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Sample records for coalbed methane

  1. Enhanced coalbed methane recovery

    SciTech Connect

    Mazzotti, M.; Pini, R.; Storti, G.

    2009-01-15

    The recovery of coalbed methane can be enhanced by injecting CO{sub 2} in the coal seam at supercritical conditions. Through an in situ adsorption/desorption process the displaced methane is produced and the adsorbed CO{sub 2} is permanently stored. This is called enhanced coalbed methane recovery (ECBM) and it is a technique under investigation as a possible approach to the geological storage of CO{sub 2} in a carbon dioxide capture and storage system. This work reviews the state of the art on fundamental and practical aspects of the technology and summarizes the results of ECBM field tests. These prove the feasibility of ECBM recovery and highlight substantial opportunities for interdisciplinary research at the interface between earth sciences and chemical engineering.

  2. Method for removal of methane from coalbeds

    DOEpatents

    Pasini, III, Joseph; Overbey, Jr., William K.

    1976-01-01

    A method for removing methane gas from underground coalbeds prior to mining the coal which comprises drilling at least one borehole from the surface into the coalbed. The borehole is started at a slant rather than directly vertically, and as it descends, a gradual curve is followed until a horizontal position is reached where the desired portion of the coalbed is intersected. Approaching the coalbed in this manner and fracturing the coalbed in the major natural fraction direction cause release of large amounts of the trapped methane gas.

  3. Coalbed methane production case histories

    SciTech Connect

    Not Available

    1981-02-01

    The production of methane gas from coal and coal-bearing rocks is one of the prime objectives of the Department of Energy's Methane Recovery from Coalbeds Project. This report contains brief description of wells that are presently producing gas from coal or coal-bearing rocks. Data from three gob gas production areas in Illinois, an in-mine horizontal borehole degasification, and eleven vertical boreholes are presented. Production charts and electric logs of the producing zones are included for some of the wells. Additional information on dry gas production from the San Juan Basin, Colorado/New Mexico and the Greater Green River Coal Region, Colorado/Wyoming is also included.

  4. Coalbed methane: from hazard to resource

    USGS Publications Warehouse

    Flores, R.M.

    1998-01-01

    Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 yr. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (eg, tunnels, vertical and horizontal drillholes, shsfts) and by drainage boreholes. The 1970s 'energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been pursued vigorously during the past two decades. Since the 1970s research investigations on the causes and effects of coal mine outbursts and gas emissions have led to major advances towards the recovery and development of coalbed methane for commercial use. Thus, coalbed methane as a mining hazard was harnessed as a conventional gas resource.Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 years. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (e.g., tunnels, vertical and horizontal drillholes, shafts) and by drainage boreholes. The 1970's `energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been

  5. Exploration for coalbed methane gains momentum in Uinta basin

    USGS Publications Warehouse

    Gloyn, Robert W.; Sommer, Steven N.

    1993-01-01

    A development program is planned, and at least three other companies are exploring for coalbed methane in the surrounding area. Estimates have been revised by the Utah Geological Survey for the coalbed methane potential of the southern Uinta basin. They are 8 tcf to more than the earlier estimates of 0.8-4.6 tcf.

  6. Coal-bed methane resources in Arkoma basin, southeastern Oklahoma

    SciTech Connect

    Friedman, S.A. )

    1989-08-01

    A major federal tax incentive for unconventional gas production has interested entrepreneurs, geologists, and engineers in the occurrence and distribution of coal-bed methane resources in the Arkoma basin. Because the methane is trapped in coal beds, geology of the coal resources also has received renewed attention. The Arkoma basin contains most of the coal-bed methane resources in Oklahoma: 76% of the 7.9 billion short tons of the remaining, identified Middle Pennsylvanian coal resources of the state. This paper briefly reviews previous estimates of coal-bed methane resources in Oklahoma and presents an updated estimate for Haskell and LeFlore Counties and a new estimate for Latimer County. Rieke and Kirr indicated that 2.8 tcf of coal-bed methane is present in 10 coals in eight Oklahoma counties of the Arkoma basin, 500-3,000 ft deep. Iannacchione and Puglio estimated that a maximum of 1.5 tcf of coal-bed methane occurs in the Hartshorne coals in Haskell and LeFlore Counties from 500-3,000 ft deep. The present investigation shows that the Hartshorne and 11 other coals contain at least 1.8 tcf of coal-bed methane resources, based on identified coal resources 500-3,000 ft deep in Haskell, Latimer, and LeFlore Counties. An additional 1.2 tcf of coal-bed methane resources occur in the Hartshorne and four other coals from 3,000-7,000 ft deep, based on assumed stratigraphic and thickness continuity. Thus, a revised estimate indicates that Haskell, Latimer, and LeFlore Counties alone contain about 3 tcf of coal-bed methane resources in 12 coal beds from 500-7,000 ft deep. Undoubtedly additional coal-bed methane resources are present in the westernmost part of the Arkoma basin.

  7. Enhancement of Biogenic Coalbed Methane Production and Back Injection of Coalbed Methane Co-Produced Water

    SciTech Connect

    Song Jin

    2007-05-31

    Biogenic methane is a common constituent in deep subsurface environments such as coalbeds and oil shale beds. Coalbed methane (CBM) makes significant contributions to world natural gas industry and CBM production continues to increase. With increasing CBM production, the production of CBM co-produced water increases, which is an environmental concern. This study investigated the feasibility in re-using CBM co-produced water and other high sodic/saline water to enhance biogenic methane production from coal and other unconventional sources, such as oil shale. Microcosms were established with the selected carbon sources which included coal, oil shale, lignite, peat, and diesel-contaminated soil. Each microcosm contained either CBM coproduced water or groundwater with various enhancement and inhibitor combinations. Results indicated that the addition of nutrients and nutrients with additional carbon can enhance biogenic methane production from coal and oil shale. Methane production from oil shale was much greater than that from coal, which is possibly due to the greater amount of available Dissolved Organic Carbon (DOC) from oil shale. Inconclusive results were observed from the other sources since the incubation period was too low. WRI is continuing studies with biogenic methane production from oil shale.

  8. Raton basin coalbed methane production picking up in Colorado

    USGS Publications Warehouse

    Hemborg, H. Thomas

    1996-01-01

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has gone over pilot testing and entered the development stage which is expected to last several years. The development work is restricted to roughly a 25 mile by 15 mile wide `fairway' centered about 20 miles west of Trinidad, Colorado. At last count, 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin's Raton and Vermejo formation coals.

  9. Coalbed methane: Clean energy for the world

    USGS Publications Warehouse

    Ahmed, A.-J.; Johnston, S.; Boyer, C.; Lambert, S.W.; Bustos, O.A.; Pashin, J.C.; Wray, A.

    2009-01-01

    Coalbed methane (CBM) has the potential to emerge as a significant clean energy resource. It also has the potential to replace other diminishing hydrocarbon reserves. The latest developments in technologies and methodologies are playing a key role in harnessing this unconventional resource. Some of these developments include adaptations of existing technologies used in conventional oil and gas generations, while others include new applications designed specifically to address coal's unique properties. Completion techniques have been developed that cause less damage to the production mechanisms of coal seams, such as those occurring during cementing operations. Stimulation fluids have also been engineered specifically to enhance CBM production. Deep coal deposits that remain inaccessible by conventional mining operations offer CBM development opportunities.

  10. Exploiting coalbed methane and protecting the global environment

    SciTech Connect

    Yuheng, Gao

    1996-12-31

    The global climate change caused by greenhouse gases (GHGs) emission has received wide attention from all countries in the world. Global environmental protection as a common problem has confronted the human being. As a main component of coalbed methane, methane is an important factor influencing the production safety of coal mine and threatens the lives of miners. The recent research on environment science shows that methane is a very harmful GHG. Although methane gas has very little proportion in the GHGs emission and its stayed period is also very short, it has very obvious impact on the climate change. From the estimation, methane emission in the coal-mining process is only 10% of the total emission from human`s activities. As a clean energy, Methane has mature recovery technique before, during and after the process of mining. Thus, coalbed methane is the sole GHG generated in the human`s activities and being possible to be reclaimed and utilized. Compared with the global greenhouse effect of other GHGs emission abatement, coalbed methane emission abatement can be done in very low cost with many other benefits: (1) to protect global environment; (2) to improve obviously the safety of coal mine; and (3) to obtain a new kind of clean energy. Coal is the main energy in China, and coalbed contains very rich methane. According to the exploration result in recent years, about 30000{approximately}35000 billion m{sup 2} methane is contained in the coalbed below 2000 m in depth. China has formed a good development base in the field of reclamation and utilization of coalbed methane. The author hopes that wider international technical exchange and cooperation in the field will be carried out.

  11. Structural control of coalbed methane production in Alabama

    USGS Publications Warehouse

    Pashin, J.C.; Groshong, R.H.

    1998-01-01

    Thin-skinned structures are distributed throughout the Alabama coalbed methane fields, and these structures affect the production of gas and water from coal-bearing strata. Extensional structures in Deerlick Creek and Cedar Cove fields include normal faults and hanging-wall rollovers, and area balancing indicates that these structures are detached in the Pottsville Formation. Compressional folds in Gurnee and Oak Grove fields, by comparison, are interpreted to be detachment folds formed above decollements at different stratigraphic levels. Patterns of gas and water production reflect the structural style of each field and further indicate that folding and faulting have affected the distribution of permeability and the overall success of coalbed methane operations. Area balancing can be an effective way to characterize coalbed methane reservoirs in structurally complex regions because it constrains structural geometry and can be used to determine the distribution of layer-parallel strain. Comparison of calculated requisite strain and borehole expansion data from calliper logs suggests that strain in coalbed methane reservoirs is predictable and can be expressed as fracturing and small-scale faulting. However, refined methodology is needed to analyze heterogeneous strain distributions in discrete bed segments. Understanding temporal variation of production patterns in areas where gas and water production are influenced by map-scale structure will further facilitate effective management of coalbed methane fields.Thin-skinned structures are distributed throughout the Alabama coalbed methane fields, and these structures affect the production of gas and water from coal-bearing strata. Extensional structures in Deerlick Creek and Cedar Cove fields include normal faults and hanging-wall rollovers, and area balancing indicates that these structures are detached in the Pottsville Formation. Compressional folds in Gurnee and Oak Grove fields, by comparison, are interpreted to

  12. Economic analysis of vertical wells for coalbed methane recovery

    SciTech Connect

    Not Available

    1981-04-01

    Previous economic studies of the recovery and utilization of methane from coalbeds using vertical wells were based on drainage in advance of mining where a single seam is drained with well spacing designed for rapid predrainage. This study extends the earlier work and shows that methane recovery costs can be reduced significantly by increasing well spacing and draining multiple coalbeds. A favorable return on investment can be realized in many geologic settings using this method. Sensitivity of recovery economics to certain development costs and parametric variations are also examined as are the economics of three methane utilization options.

  13. Coalbed methane production potential in U. S. basins

    SciTech Connect

    Byer, C.W.; Mroz, T.H.; Covatch, G.L.

    1987-07-01

    The major emphasis of the U.S. DOE's coalbed methane research has been on estimating the magnitude of the resource and developing systems for recovery. Methane resource estimates for 16 basins show that the greatest potential is in the Piceance, Northern Appalachian, Central Appalachian, Powder River, and Greater Green River coal basins. Small, high-potential target areas have been selected for in-depth analysis of the resource. Industry interest is greatest in the Warrior, San Juan, Piceance, Raton Mesa, and Northern and Central Appalachian basins. Production curves for several coalbed methane wells in these basins are included.

  14. Coalbed methane resource potential and current prospects in Pennsylvania

    USGS Publications Warehouse

    Markowski, A.K.

    1998-01-01

    Coalbed methane gas content analyses from exploratory coal cores and existing data indicate that gas content generally increases with increasing depth and rank. The coal beds studied are from the Main Bituminous field of Pennsylvania (which currently contains 24 coalbed methane pools) and the Northern and Southern Anthracite coal fields. They range from the Middle Pennsylvanian Allegheny Group to the Late Pennsylvanian-Early Permian Dunkard Group. Previous US Bureau of Mines studies revealed gas contents from 0.4 to 13.8 cm3/g at depths of 99 to 432 m for the bituminous coal beds of the Allegheny Group. More recent core data from the Allegheny Group yielded gas contents from 2.2 to 8.9 cm3/g at depths from 167 to 387 m. In the Anthracite region of eastern Pennsylvania, the little data that are available show that gas content is anomalously high or low. Gas yields from test holes in eastern Pennsylvania are low with or without artificial stimulation mainly due to the lack of a good cleat system. Overall estimates of coalbed methane resources indicate there may be 1.7 Tm3 (61 Tcf) of gas-in-place contained in the Northern Appalachian coal basin. The amount of technically recoverable coalbed methane resources is projected by the US Geological Survey National Oil and Gas Resource Assessment Team [US Geological Survey National Oil and Gas Resource Assessment Team, 1996. 1995 National assessment of United States oil and gas resources-results, methodology, and supporting data, US Geological Survey Digital Data Series DDS-30, CD-ROM, Denver, CO, 80 pp.] and Lyons [Lyons, P.C., 1997. Central-northern Appalachian coalbed methane flow grows. Oil and Gas Journal 95 (27) 76-79] at 0.3 Tm3 (11.48 Tcf). This includes portions of Pennsylvania, Ohio, West Virginia, and a small part of Maryland. Consequently, a mapping investigation was conducted to evaluate the regional geology of the bituminous coal-bearing intervals in southwestern Pennsylvania and its influence on coalbed

  15. Methane recovery from coalbeds: a potential energy source

    SciTech Connect

    Mroz, T.H.; Ryan, J.G.; Byrer, C.W.

    1983-10-01

    This document integrates all of the available geologic and coal resource data that have been acquired in the Coalbed Methane Project over the past 5 years to determine the stratigraphic units and geographical areas wherein the methane production potential is classified as favorable. Sixteen basins were included in this compilation. Each basin is a chapter in this report. The chapter write-ups feature sections on geology, coal resource, potential methane resource and recommendations for development of the technology base needed to estimate recovery potential. Information used in the sections is supported by a list of references. The integration of these data has removed much of the uncertainty about what production potential exists and where the favorable trends are located in the basin. This will aid the producers who are considering well-drilling ventures for coalbed methane recovery. Estimates of production performance from any new wells can only be developed once fundamental reservoir property measurements are acquired. This is the next field activity required. Preliminary results of the coalbed methane resource effort show that many of the coal regions in the US have significant volumes of coalbed methane. The evaluation of the core desorption data from over 50 cooperative wells has helped DOE to refine the in-place methane estimates of the various coal regions. The summary of the methane resource estimates for 16 basins is shown in the Summary of Results Table. Based upon these initial results, the basins showing a high resource estimate of coalbed methane include the Piceance, Northern Appalachian, Central Appalachian, Powder River, and Greater Green River.

  16. Evaluation of coalbed methane resource in western United States

    SciTech Connect

    Choate, R.

    1984-04-01

    Of the new or unconventional fossil energy resources studied in recent years with federal, state, or industry funding, the recovery of methane from coalbeds is the one resource with the greatest probable near-term commercial potential. Well completion records and production data indicate that much, if not most, of the gas currently produced from the Fruitland Formation of the San Juan basin, for example, has its origin in or from coalbeds. All of the intermontane sedimentary basins of the Rocky Mountain region underlain by coal deposits, also contain methane that is genetically associated with those coals. Discussed will be individual characteristics of some of these basins that bear on methane formation and accumulation in each basin, techniques for estimating methane resources and defining target areas for exploration, amounts of gas contained in the basins, and identification of some completion and production problems. Basins specifically discussed will include Piceance, San Juan, Raton, and Powder River.

  17. Preliminary resource assessment of coalbed methane in the United States

    SciTech Connect

    Not Available

    1981-04-01

    Preliminary results of the DOE Methane Recovery from Coalbeds Project reveal that many of the coal regions in the United States have significant volumes of coalbed methane. These results show that 45 cooperative wells drilled to date have helped to update the estimates of methane in the various coal regions. The most promising coal region is in the Green River Basin where preliminary estimates show that the methane potential may be over 23 trillion cubic feet. Another area of considerable interest is in the Arkoma Basin where the methane content of coal samples ranged from 200 to 400 cubic feet per ton (cf/ton) of coal. The methane estimte in this basin is between 1.6 to 3.6 trillion cubic feet. The Piceance Creek coal region is an area presently generating considerable interest and industry activity. The methane content of the coal samples extracted from this basin averaged over 100 cf/ton. The Northern Appalachian region also shows considerable promise.

  18. Raton basin coalbed methane production picking up in Colorado

    SciTech Connect

    Hemborg, H.T.

    1996-11-11

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has advanced past pilot testing and is entering into a development stage that should stretch out over several years. At last count 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin`s Raton and Vermejo formation coals (Early Paleocene to Latest Maastrichtian). This development work is currently restricted to roughly a 25 mile by 15 mile wide ``fairway`` centered about 20 miles west of Trinidad, Colo., in the headwater area of the Purgatoire River. The paper discusses the companies involved in the basin development, geology of the coal seam, and water disposal from coal seam dewatering.

  19. Coalbed methane exploration in the Lorraine Basin, France

    SciTech Connect

    Michaud, B.; Briens, F.; Girdler, D.

    1995-08-01

    DuPont Conoco Hydrocarbures has been involved in a Coalbed Methane (CBM) project in France since 1991. Coalbed methane exploration differs noticeably in several aspects from conventional oil and gas exploration. This paper is divided in three parts and discusses some geological, reservoir and drilling considerations relevant to the exploration and appraisal of a coalbed methane prospect. The first part presents geological issues such as data collection and evaluation of its associated value, building expertise to create a geological and geophysical model integrating the work of a multidisciplinary team, and assessing uncertainties of the data interpretation. A short review of the basin activity, geological and tectonic setting, and environment aspects is presented in order to illustrate some CBM exploration issues. The second part describes a comprehensive coalbed methane reservoir data acquisition program incorporating coal sample optical and chemical analyses, gas sample chromatography, canister desorption, fracture density of coal cores, and measurement of in-situ coal permeability and bounding-strata stress. Field practical concerns are then discussed such as on-site and off-site canister desorption, gas sample collection, rapid estimation of gas content, ash content, total bed moisture, and finally well testing alternatives for permeability and rock stress determination. The third part reviews drilling issues such as drilling and coring options for core hole size and casing size, rig site equipment requirements for continuous coring operations, including mud treatment equipment, core handling material and core work stations, alliance of national and foreign drilling contractors to optimize equipment and experience, and finally overview of coring procedures to identify best practices for pending operations. The paper is derived from Conoco`s experience in CBM exploration in the Lorraine Basin, North East of France.

  20. Exploration for coalbed methane starts up in northwestern Nova Scotia

    SciTech Connect

    Sakashita, B.J. )

    1993-03-29

    A consortium of three Canadian companies and a U.S. firm, Resources Enterprises Inc. (REI), Salt Lake City, has been awarded the rights for coalbed methane gas exploration on 250,000 acres in the Cumberland basin of Nova Scotia, Canada. The license agreement requires that geological and engineering studies be performed during 1993 to select exploratory well locations. Three slimhole wells must be drilled by yearend 1994, and three production test wells must be completed by yearend 1995. The paper describes the Cumberland basin exploration license; market outlets for the methane; and geothermal potential of the Cumberland basin in combination with dewatering the coal seam.

  1. Coalbed methane resources of the Appalachian Basin, eastern USA

    USGS Publications Warehouse

    Milici, Robert C.; Hatch, Joseph R.; Pawlewicz, Mark J.

    2010-01-01

    In 2002, the U.S. Geological Survey (USGS) assessed the technically recoverable, undiscovered coalbed-gas resources in the Appalachian basin and Black Warrior basin Assessment Provinces as about 15.5 trillion cubic feet. Although these resources are almost equally divided between the two areas, most of the production occurs within relatively small areas within these Provinces, where local geological and geochemical attributes have resulted in the generation and retention of large amounts of methane within the coal beds and have enhanced the producibility of the gas from the coal. In the Appalachian basin, coalbed methane (CBM) tests are commonly commercial where the cumulative coal thickness completed in wells is greater than three meters (10 ft), the depth of burial of the coal beds is greater than 100 m (350 ft), and the coal is in the thermogenic gas window. In addition to the ubiquitous cleating within the coal beds, commercial production may be enhanced by secondary fracture porosity related to supplemental fracture systems within the coal beds. In order to release the methane from microporus coal matrix, most wells are dewatered prior to commercial production of gas. Two Total Petroleum Systems (TPS) were defined by the USGS during the assessment: the Pottsville Coal-bed gas TPS in Alabama, and the Carboniferous Coal-bed Gas TPS in Pennsylvania, Ohio, West Virginia, eastern Kentucky, Virginia, Tennessee, and Alabama. These were divided into seven assessment units, of which three had sufficient data to be assessed. Production rates are higher in most horizontal wells drilled into relatively thick coal beds, than in vertical wells; recovery per unit area is greater, and potential adverse environmental impact is decreased.

  2. State-of-the-art in coalbed methane drilling fluids

    SciTech Connect

    Baltoiu, L.V.; Warren, B.K.; Natras, T.A.

    2008-09-15

    The production of methane from wet coalbeds is often associated with the production of significant amounts of water. While producing water is necessary to desorb the methane from the coal, the damage from the drilling fluids used is difficult to assess, because the gas production follows weeks to months after the well is drilled. Commonly asked questions include the following: What are the important parameters for drilling an organic reservoir rock that is both the source and the trap for the methane? Has the drilling fluid affected the gas production? Are the cleats plugged? Does the 'filtercake' have an impact on the flow of water and gas? Are stimulation techniques compatible with the drilling fluids used? This paper describes the development of a unique drilling fluid to drill coalbed methane wells with a special emphasis on horizontal applications. The fluid design incorporates products to match the delicate surface chemistry on the coal, a matting system to provide both borehole stability and minimize fluid losses to the cleats, and a breaker method of removing the matting system once drilling is completed. This paper also discusses how coal geology impacts drilling planning, drilling practices, the choice of drilling fluid, and completion/stimulation techniques for Upper Cretaceous Mannville-type coals drilled within the Western Canadian Sedimentary Basin. A focus on horizontal coalbed methane (CBM) wells is presented. Field results from three horizontal wells are discussed, two of which were drilled with the new drilling fluid system. The wells demonstrated exceptional stability in coal for lengths to 1000 m, controlled drilling rates and ease of running slotted liners. Methods for, and results of, placing the breaker in the horizontal wells are covered in depth.

  3. Biogeochemistry of microbial coal-bed methane

    USGS Publications Warehouse

    Strc, D.; Mastalerz, Maria; Dawson, K.; MacAlady, J.; Callaghan, A.V.; Wawrik, B.; Turich, C.; Ashby, M.

    2011-01-01

    Microbial methane accumulations have been discovered in multiple coal-bearing basins over the past two decades. Such discoveries were originally based on unique biogenic signatures in the stable isotopic composition of methane and carbon dioxide. Basins with microbial methane contain either low-maturity coals with predominantly microbial methane gas or uplifted coals containing older, thermogenic gas mixed with more recently produced microbial methane. Recent advances in genomics have allowed further evaluation of the source of microbial methane, through the use of high-throughput phylogenetic sequencing and fluorescent in situ hybridization, to describe the diversity and abundance of bacteria and methanogenic archaea in these subsurface formations. However, the anaerobic metabolism of the bacteria breaking coal down to methanogenic substrates, the likely rate-limiting step in biogenic gas production, is not fully understood. Coal molecules are more recalcitrant to biodegradation with increasing thermal maturity, and progress has been made in identifying some of the enzymes involved in the anaerobic degradation of these recalcitrant organic molecules using metagenomic studies and culture enrichments. In recent years, researchers have attempted lab and subsurface stimulation of the naturally slow process of methanogenic degradation of coal. Copyright ?? 2011 by Annual Reviews. All rights reserved.

  4. Biogeochemistry of Microbial Coal-Bed Methane

    NASA Astrophysics Data System (ADS)

    Strąpoć, Dariusz; Mastalerz, Maria; Dawson, Katherine; Macalady, Jennifer; Callaghan, Amy V.; Wawrik, Boris; Turich, Courtney; Ashby, Matthew

    2011-05-01

    Microbial methane accumulations have been discovered in multiple coal-bearing basins over the past two decades. Such discoveries were originally based on unique biogenic signatures in the stable isotopic composition of methane and carbon dioxide. Basins with microbial methane contain either low-maturity coals with predominantly microbial methane gas or uplifted coals containing older, thermogenic gas mixed with more recently produced microbial methane. Recent advances in genomics have allowed further evaluation of the source of microbial methane, through the use of high-throughput phylogenetic sequencing and fluorescent in situ hybridization, to describe the diversity and abundance of bacteria and methanogenic archaea in these subsurface formations. However, the anaerobic metabolism of the bacteria breaking coal down to methanogenic substrates, the likely rate-limiting step in biogenic gas production, is not fully understood. Coal molecules are more recalcitrant to biodegradation with increasing thermal maturity, and progress has been made in identifying some of the enzymes involved in the anaerobic degradation of these recalcitrant organic molecules using metagenomic studies and culture enrichments. In recent years, researchers have attempted lab and subsurface stimulation of the naturally slow process of methanogenic degradation of coal.

  5. Kansas coal distribution, resources, and potential for coalbed methane

    USGS Publications Warehouse

    Brady, L.L.

    2000-01-01

    Kansas has large amounts of bituminous coal both at the surface and in the subsurface of eastern Kansas. Preliminary studies indicate at least 53 billion tons (48 billion MT) of deep coal [>100 ft (>30 m)] determined from 32 different coal beds. Strippable coal resources at a depth < 100 ft (<30 m) total 2.8 billion tons (2.6 billion MT), and this total is determined from 17 coals. Coal beds present in the Cherokee Group (Middle Pennsylvanian) represent most of these coal resource totals. Deep coal beds with the largest resource totals include the Bevier, Mineral, "Aw" (unnamed coal bed), Riverton, and Weir-Pittsburg coals, all within the Cherokee Group. Based on chemical analyses, coals in the southeastern part of the state are generally high volatile A bituminous, whereas coals in the east-central and northeastern part of the state are high-volatile B bituminous coals. The primary concern of coal beds in Kansas for deep mining or development of coalbed methane is the thin nature [<2 ft (0.6 m)] of most coal beds. Present production of coalbed methane is centered mainly in the southern Wilson/northern Montgomery County area of southeastern Kansas where methane is produced from the Mulky, Weir-Pittsburg, and Riverton coals.

  6. Appalachian basin coal-bed methane: Elephant or flea

    SciTech Connect

    Hunt, A.M. )

    1991-08-01

    Historically, interest in the Appalachian basin coal-bed methane resource extends at least over the last 50 years. The Northern and Central Appalachian basins are estimated to contain 61 tcf and 5 tcf of coal-bed methane gas, respectively. Development of this resource has not kept pace with that of other basins, such as the Black Warrior basin of Alabama of the San Juan basin of northern New Mexico and Colorado. Without the benefit of modern completion, stimulation, and production technology, some older Appalachian basin coal-bed methane wells were reported to have produced in excess of 150 used here to characterize some past projects and their results. This work is not intended to comprise a comprehensive survey of all Appalachian basin projects, but rather to provide background information from which to proceed for those who may be interested in doing so. Several constraints to the development of this resource have been identified, including conflicting legal rights of ownership of the gas produced from the coal seams when coal and conventional oil and gas rights are controlled by separate parties. In addition, large leaseholds have been difficult to acquire and finding costs have been high. However, the threshold of minimum economic production may be relatively low when compared with other areas, because low-pressures pipelines are available and gas prices are among the highest in the nation. Interest in the commercial development of the resource seems to be on the increase with several projects currently active and more reported to be planned for the near future.

  7. Unconventional gas resources. [Eastern Gas Shales, Western Gas Sands, Coalbed Methane, Methane from Geopressured Systems

    SciTech Connect

    Komar, C.A.

    1980-01-01

    This document describes the program goals, research activities, and the role of the Federal Government in a strategic plan to reduce the uncertainties surrounding the reserve potential of the unconventional gas resources, namely, the Eastern Gas Shales, the Western Gas Sands, Coalbed Methane, and methane from Geopressured Aquifers. The intent is to provide a concise overview of the program and to identify the technical activities that must be completed in the successful achievement of the objectives.

  8. Coalbed methane could cut India`s energy deficit

    SciTech Connect

    Kelafant, J.; Stern, M.

    1998-05-25

    Foreign interest in upcoming Indian coalbed methane (CBM) concession rounds will depend on prospect quality, fiscal regime attractiveness, and perceptions interested parties will have concerning the government`s willingness to promote development. The more liberal tax and royalty provisions for foreign producers announced by the ministry of Petroleum and Natural Gas indicate that India is interested in attracting international CBM investments. This article examines the potential for developing the country`s large CBM resource base, estimated between 30 tcf (250 billion cu m) and 144 tcf (4 trillion cu m) of gas. It also provides an overview of the current contractual and regulatory framework governing CBM development.

  9. The effect of coal-bed methane water on spearmint and peppermint

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coal bed methane (CBM) is extracted from underground coal seams, flooded with water. In order to reduce the pressure and release the methane, the trapped water needs to be pumped out. The resulting ‘waste water’ is known as coal-bed methane water (CBMW). Major concerns with the use of CBMW are the h...

  10. Coal-bed methane water effects on dill and essential oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic way of methane extraction. The water that is pumped out is known as coal-bed methane water (CBMW), which is high in sodium and other salts. In past 25 years, th...

  11. Coalbed methane produced water in China: status and environmental issues.

    PubMed

    Meng, Yanjun; Tang, Dazhen; Xu, Hao; Li, Yong; Gao, Lijun

    2014-01-01

    As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing.

  12. Alaska coal geology, resources, and coalbed methane potential

    USGS Publications Warehouse

    Flores, Romeo M.; Stricker, Gary D.; Kinney, Scott A.

    2004-01-01

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines in these two provinces. Alaskan coal resources have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. The identified resources are near existing and planned infrastructure to promote development, transportation, and marketing of this low-sulfur coal. The relatively short distances to countries in the west Pacific Rim make them more exportable to these countries than to the lower 48 States of the United States. Another untapped but potential resource of large magnitude is coalbed methane, which has been estimated to total 1,000 trillion cubic feet (28 trillion cubic meters) by T.N. Smith 1995, Coalbed methane potential for Alaska and drilling results for the upper Cook Inlet Basin: Intergas, May 15 - 19, 1995, Tuscaloosa, University of Alabama, p. 1 - 21.

  13. Coalbed methane produced water in China: status and environmental issues.

    PubMed

    Meng, Yanjun; Tang, Dazhen; Xu, Hao; Li, Yong; Gao, Lijun

    2014-01-01

    As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing. PMID:24599657

  14. Montana's Coalbed Methane Ground-Water Monitoring Program: Year One

    NASA Astrophysics Data System (ADS)

    Wheaton, J. R.; Smith, M.; Donato, T. A.; Bobst, A. L.

    2003-12-01

    Tertiary coal seams in the Powder River Basin in southeastern Montana provide three very important resources: ground water, coal, and natural gas. Ground water from springs and wells is essential for the local agricultural economy. Because coal seams in the Fort Union Formation have higher hydraulic conductivity values and are more continuous than the sandstone units, they are the primary aquifers in this region. Coalbed methane (CBM) production is beginning in the Powder River Basin, and requires removal and management of large quantities of water from the coal-seam aquifers. The extensive pumping required to produce the methane is expected to create broad areas of severe potentiometric decline. The Montana CBM ground-water monitoring program, now in place, is based on scientific concepts developed during more than 30 years of coal-mine hydrogeology research. The program includes inventories of ground-water resources and regular monitoring at dedicated wells and selected springs. The program is now providing baseline potentiometric and water-quality data, and will continue to be active through the duration of CBM production and post-production ground-water recovery. An extensive inventory of ground-water resources in the Montana portion of the Powder River Basin has located 300 springs and 21 wells on private land, and 460 springs and 21 wells on U. S. Forest Service and U. S. Bureau of Land Management land, all producing ground water from the methane bearing strata. In southeastern Montana, 134 monitoring wells are currently included in the CBM monitoring program. They are completed either in coal seams, adjacent sandstone units, or alluvium. During the coal boom of the 1970's and 1980's many monitoring wells were drilled, but most have been since unused. Thirty-six of these existing wells have now been returned to service to decrease start-up costs for the CBM program. This network of existing wells has been augmented at key sites with 26 new wells drilled

  15. Temperature-pressure conditions in coalbed methane reservoirs of the Black Warrior basin: Implications for carbon sequestration and enhanced coalbed methane recovery

    USGS Publications Warehouse

    Pashin, J.C.; McIntyre, M.R.

    2003-01-01

    Sorption of gas onto coal is sensitive to pressure and temperature, and carbon dioxide can be a potentially volatile supercritical fluid in coalbed methane reservoirs. More than 5000 wells have been drilled in the coalbed methane fields of the Black Warrior basin in west-central Alabama, and the hydrologic and geothermic information from geophysical well logs provides a robust database that can be used to assess the potential for carbon sequestration in coal-bearing strata.Reservoir temperature within the coalbed methane target zone generally ranges from 80 to 125 ??F (27-52 ??C), and geothermal gradient ranges from 6.0 to 19.9 ??F/1000 ft (10.9-36.2 ??C/km). Geothermal gradient data have a strong central tendency about a mean of 9.0 ??F/1000 ft (16.4 ??C/km). Hydrostatic pressure gradients in the coalbed methane fields range from normal (0.43 psi/ft) to extremely underpressured (<0.05 psi/ft). Pressure-depth plots establish a bimodal regime in which 70% of the wells have pressure gradients greater than 0.30 psi/ft, and 20% have pressure gradients lower than 0.10 psi/ft. Pockets of underpressure are developed around deep longwall coal mines and in areas distal to the main hydrologic recharge zone, which is developed in structurally upturned strata along the southeastern margin of the basin.Geothermal gradients within the coalbed methane fields are high enough that reservoirs never cross the gas-liquid condensation line for carbon dioxide. However, reservoirs have potential for supercritical fluid conditions beyond a depth of 2480 ft (756 m) under normally pressured conditions. All target coal beds are subcritically pressured in the northeastern half of the coalbed methane exploration fairway, whereas those same beds were in the supercritical phase window prior to gas production in the southwestern half of the fairway. Although mature reservoirs are dewatered and thus are in the carbon dioxide gas window, supercritical conditions may develop as reservoirs

  16. Results from Coalbed Methane Drilling in Winn Parish, Louisiana

    USGS Publications Warehouse

    Hackley, Paul C.; Warwick, Peter D.; Breland, F. Clayton; Richard, Troy E.; Ross, Kirk

    2007-01-01

    A coalbed methane (CBM) well in Winn Parish, Louisiana, named CZ Fee A No. 114, was drilled by Vintage Petroleum, Inc., in January 2004. The CZ Fee A No. 114 CBM well was drilled to a total depth of 3,114 ft and perforated at 2,730-2,734 ft in a Wilcox Group (Paleocene-Eocene) coal bed. Analytical data from the drilling project have been released by Vintage Petroleum, Inc., and by the current well operator, Hilcorp Energy Corporation (see Appendix) to the Louisiana Geological Survey (LGS) and the U.S. Geological Survey (USGS) for publication. General information about the CZ Fee A No. 114 CBM well is compiled in Table 1, and analytical data from the well are included in following sections. The CZ Fee A No. 114 well is located in eastern Winn Parish, approximately 30 mi east of where Wilcox Group strata crop out on the Sabine Uplift (fig. 1). In the CZ Fee A No. 114 well, lower Wilcox Paleocene coal beds targeted for CBM production occur at depths of 2,600-3,000 ft (fig. 2). Average monthly gas production for the reporting period August 1, 2004, through May 1, 2005, was 450 thousand cubic feet (Mcf) (Louisiana Department of Natural Resources, 2005).

  17. Alaska coal geology, resources, and coalbed methane potential

    SciTech Connect

    Romeo M. Flores; Gary D. Stricker; Scott A. Kinney

    2005-11-15

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces, Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines. Alaskan coals have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States and are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. Another untapped potential resource is coalbed methane estimated to total 1,000 trillion cubic feet (28 trillion cubic meters).

  18. Stratigraphy and structure of coalbed methane reservoirs in the United States: an overview

    USGS Publications Warehouse

    Pashin, J.C.

    1998-01-01

    Stratigraphy and geologic structure determine the shape, continuity and permeability of coal and are therefore critical considerations for designing exploration and production strategies for coalbed methane. Coal in the United states is dominantly of Pennsylvanian, Cretaceous and Tertiary age, and to date, more than 90% of the coalbed methane produced is from Pennsylvanian and cretaceous strata of the Black Warrior and San Juan Basins. Investigations of these basins establish that sequence stratigraphy is a promising approach for regional characterization of coalbed methane reservoirs. Local stratigraphic variation within these strata is the product of sedimentologic and tectonic processes and is a consideration for selecting completion zones. Coalbed methane production in the United States is mainly from foreland and intermontane basins containing diverse compression and extensional structures. Balanced structural models can be used to construct and validate cross sections as well as to quantify layer-parallel strain and predict the distribution of fractures. Folds and faults influence gas and water production in diverse ways. However, interwell heterogeneity related to fractures and shear structures makes the performance of individual wells difficult to predict.Stratigraphy and geologic structure determine the shape, continuity and permeability of coal and are therefore critical considerations for designing exploration and production strategies for coalbed methane. Coal in the United States is dominantly of Pennsylvanian, Cretaceous and Tertiary age, and to date, more than 90% of the coalbed methane produced is from Pennsylvanian and Cretaceous strata of the Black Warrior and San Juan Basins. Investigations of these basins establish that sequence stratigraphy is a promising approach for regional characterization of coalbed methane reservoirs. Local stratigraphic variation within these strata is the product of sedimentologic and tectonic processes and is a

  19. Methane recovery from coalbeds project. Monthly progress report

    SciTech Connect

    Not Available

    1980-11-01

    Progress made on the Methane Recovery from Coalbeds Project (MRCP) is reported in the Raton Mesa Coal Region. The Uinta and Warrior basin reports have been reviewed and will be published and delivered in early December. A cooperative core test with R and P Coal Company on a well in Indiana County, Pennsylvania, was negotiated. In a cooperative effort with the USGS Coal Branch on three wells in the Wind River Basin, desorption of coal samples showed little or no gas. Completed field testing at the Dugan Petroleum well in the San Juan Basin. Coal samples showed minimal gas. Initial desorption of coal samples suggests that at least a moderate amount of gas was obtained from the Coors well test in the Piceance Basin. Field work for the Piceance Basin Detailed Site Investigation was completed. In the Occidental Research Corporation (ORC) project, a higher capacity vacuum pump to increase CH/sub 4/ venting operations has been installed. Drilling of Oxy No. 12 experienced delays caused by mine gas-offs and was eventually terminated at 460 ft after an attempt to drill through a roll which produced a severe dog leg and severely damaged the drill pipe. ORC moved the second drill rig and equipment to a new location in the same panel as Oxy No. 12 and set the stand pipe for Oxy No. 13. Drill rig No. 1 has been moved east of the longwall mining area in anticipation of drilling cross-panel on 500 foot intervals. Waynesburg College project, Equitable Gas Company has received the contract from Waynesburg College and has applied to the Pennsylvania Public Utilities Commission for a new tariff rate. Waynesburg College has identified a contractor to make the piping connections to the gas line after Equitable establishes their meter and valve requirements.

  20. Chemistry of trace elements in coalbed methane product water.

    PubMed

    McBeth, Ian; Reddy, Katta J; Skinner, Quentin D

    2003-02-01

    Extraction of methane (natural gas) from coal deposits is facilitated by pumping of aquifer water. Coalbed methane (CBM) product water, produced from pumping ground water, is discharged into associated unlined holding ponds. The objective of this study was to examine the chemistry of trace elements in CBM product water at discharge points and in associated holding ponds across the Powder River Basin, Wyoming. Product water samples from discharge points and associated holding ponds were collected from the Cheyenne River (CHR), Belle Fourche River (BFR), and Little Powder River (LPR) watersheds during the summers of 1999 and 2000. Samples were analyzed for pH, Al (aluminum), As (arsenic), B (boron), Ba (barium), Cr (chromium), Cu (copper), F (fluoride), Fe (iron), Mn (manganese), Mo (molybdenum), Se (selenium), and Zn (zinc). Chemistry of trace element concentrations were modeled with the MINTEQA2 geochemical equilibrium model. Results of this study show that pH of product water for three watersheds increased in holding ponds. For example the pH of CBM product water increased from 7.21 to 8.26 for LPR watershed. Among three watersheds, the CBM product water exhibited relatively less change in trace element concentrations in CHR watershed holding ponds. Concentration of dissolved Al, Fe, As, Se, and F in product water increased in BFR watershed holding ponds. For example, concentration of dissolved Fe increased from 113 to 135 microg/L. Boron, Cu, and Zn concentrations of product water did not change in BFR watershed holding ponds. However, concentration of dissolved Ba, Mn, and Cr in product water decreased in BFR watershed holding ponds. For instance, Ba and Cr concentrations decreased from 445 to 386 microg/L and from 43.6 to 25.1 microg/L, respectively. In the LPR watershed, Al, Fe, As, Se, and F concentrations of product water increased substantially in holding ponds. For example, Fe concentration increased from 192 to 312 microg/L. However, concentration of

  1. Gas-lift technology applied to dewatering of coalbed methane wells in the black warrior basin

    SciTech Connect

    Johnson, K.J.; Coats, A. ); Marinello, S.A. )

    1992-11-01

    Coalbed methane (CBM) wells are usually dewatered with sucker rod or progressive cavity pumps to reduce wellbore water levels, although not without problems. This paper describes high-volume artificial-lift technology that incorporates specifically designed gas-lift methods to dewater Black Warrior CBM wells. Gas lift provides improved well maintenance and production optimization by the use of conventional wireline service methods.

  2. Sage-Grouse and Coal-Bed Methane: Can They Coexist within the Powder River Basin?

    ERIC Educational Resources Information Center

    Duncan, Michael B.

    2010-01-01

    Concerns are growing regarding the availability of sustainable energy sources due to a rapidly growing human population and a better understanding of climate change. In recent years, the United States has focused much attention on developing domestic energy sources, which include coal-bed methane (CBM). There are vast deposits of the natural gas…

  3. Hydrogeological condition patterns of Kuznetsk Basin coalbed methane fields for estimating hydrodynamic calculations

    NASA Astrophysics Data System (ADS)

    Alexander, Gridasov; Konstantin, Kuzevanov; Anna, Bogdanova

    2016-09-01

    The paper describes the natural regional conditions and key formation factors of groundwater dynamics. Characteristic hydrogeological structure elements for Kuznetsk Basin coal were identified providing parameter-oriented hydrodynamic calculations and hydrogeological models in predicting coalbed methane mining impact on the regional groundwater.

  4. Coalbed methane: A partial solution to Indonesia`s growing energy problems

    SciTech Connect

    Murray, D.K.; Gold, J.P.

    1995-04-01

    Indonesia contains the largest resources of coal in Southeast Asia. Indonesian scientists estimate that the in-place coalbed methane resource in 16 onshore basins is about 213 Tcf ({approximately}6 Tcm). This volume is approximately double Indonesia`s current reserves of natural gas. Indonesia is a rapidly industrializing nation of 186 million people, of which 111 million live in Java and 38 million in Sumatra. As industrialization progresses from the present low level, the growth in energy demand will be very rapid. Indonesia`s domestic gas demand is expected to increase form 1.6 Bcf/d (0.05 Bcm/d) in 1991 to 5.7 Bcf/d (0.2 Bcm/d) in 2021. Because the major gas resources of East Kalimantan, North Sumatra, and Natuna are so remote from the main consuming area in northwest Java and are dedicated for export by virtue of the national energy policy, the need is becoming urgent to develop new resources of natural gas, including coalbed methane, for the domestic market. Due to the high geothermal gradient, the coal deposits in the back-arc basins of Sumatra and Java are expected to be of higher than normal rank at depths favorable for coalbed methane production. The oil- and gas-productive Jatibarang sub-basin in northwest Java, with estimated in-place resources of coalbed methane in excess of 20 Tcf (0.6 Tcm), is considered to be the most prospective area in Indonesia for the near-term development of coalbed methane. This area includes Jakarta and vicinity, the most populous and most heavily industrialized part of Indonesia.

  5. Method for Determining the Coalbed Methane Content with Determination the Uncertainty of Measurements

    NASA Astrophysics Data System (ADS)

    Szlązak, Nikodem; Korzec, Marek

    2016-06-01

    Methane has a bad influence on safety in underground mines as it is emitted to the air during mining works. Appropriate identification of methane hazard is essential to determining methane hazard prevention methods, ventilation systems and methane drainage systems. Methane hazard is identified while roadways are driven and boreholes are drilled. Coalbed methane content is one of the parameters which is used to assess this threat. This is a requirement according to the Decree of the Minister of Economy dated 28 June 2002 on work safety and hygiene, operation and special firefighting protection in underground mines. For this purpose a new method for determining coalbed methane content in underground coal mines has been developed. This method consists of two stages - collecting samples in a mine and testing the sample in the laboratory. The stage of determining methane content in a coal sample in a laboratory is essential. This article presents the estimation of measurement uncertainty of determining methane content in a coal sample according to this methodology.

  6. Gas Research Institute`s coalbed methane research: Selected bibliography. (Preliminary issue). Topical report, October 1994

    SciTech Connect

    Picciano, L.

    1994-10-01

    The coalbed methane citations listed here are select research reports, papers and workshop citations that were sponsored and managed by the Gas Research Institute. The initial section cites papers and reports that provide a general overview of coalbed methane production including GRI and GRI contractor paper featured in GRI publications, GRI meetings and overview volumes published by AAPG and SPE. The second section highlights general publications based on GRI`s extensive field research efforts in the eastern and western United States. The remaining sections have specific technology focuses, i.e., hydraulic fracturing. Also included is a section that features key research and results in environmental safety issues related to the production of methane from coal seams, particularly the production and disposal of produced waters.

  7. Demonstration projects for coalbed methane and Devonian shale gas: Final report. [None

    SciTech Connect

    Verrips, A.M.; Gustavson, J.B.

    1987-04-01

    In 1979, the US Department of Energy provided the American Public Gas Association (APGA) with a grant to demonstrate the feasibility of bringing unconventional gas such as methane produced from coalbeds or Devonian Shale directly into publicly owned utility system distribution lines. In conjunction with this grant, a seven-year program was initiated where a total of sixteen wells were drilled for the purpose of providing this untapped resource to communities who distribute natural gas. While coalbed degasification ahead of coal mining was already a reality in several parts of the country, the APGA demonstration program was aimed at actual consumer use of the gas. Emphasis was therefore placed on degasification of coals with high methane gas content and on utilization of conventional oil field techniques. 13 figs.

  8. Coal-bed methane in Utah, New Mexico, Colorado, and Wyoming: Resources, reserves, and production

    SciTech Connect

    Sommer, S.N. ); DeBruin, R.H. ); Tremain, C.M. ); Whitehead, N.H. III )

    1993-08-01

    Coal-bed methane reserves of 10 tcf, in-place resources up to 250 tcf, and dramatically increased production rates from Cretaceous and Tertiary formations affirm the importance of the Rocky Mountain gas province well into the 21st century. These resources have been calculated for the individual states and basins using a variety of criteria and methods and the resource numbers are not necessarily comparable. The Book Cliffs, Emery, Wastach Plateau, Kaiparowits Plateau, and Sego coal fields in Utah contain a coal-bed methane resource of 10.4 tcf. The Book Cliffs and Emery coal fields contain 8.3 tcf or 80% of this resource. The San Juan basin, New Mexico and Colorado, has 10 tcf (reserves), 40 tcf (resources) in the Fruitland Formation, and 28 tcf (resources) in the Menefee Formation. The Raton basin, Colorado and New Mexico, has 10.2 tcf of resources in the Raton and Vermejo Formations. The Piceance and Sand Wash basins in Colorado have estimated resources of more than 96 tcf. The Powder River, Green River, Hams Fork, Wind River, Hanna, Rock Creek, and Bighorn coal fields in Wyoming have resources of 54.4 tcf. The Powder River, Wind River, Green River, and Hams Fork coal fields contain 87% of this resource. In August, 1992, coal-bed methane production accounted for 49% of all gas produced from the San Juan basin (New Mexico) and 30% of all New Mexico production. For 1991, coal-bed methane production in Colorado from the San Juan and Piceance basins was 16% of all Colorado gas production.

  9. Geologic and hydrologic controls on coalbed methane producibility, Williams Fork Formation, Piceance Basin, Colorado

    SciTech Connect

    Tyler, R.; Scott, A.R.; Kaiser, W.R.; Nance, H.S.; McMurry, R.G. )

    1996-01-01

    Structural and depositional setting, coal rank, gas content, permeability, hydrodynamics, and reservoir heterogeneity control the producibility of coalbed methane in the Piceance Basin. The coal-rich Upper Cretaceous, Williams Fork Formation is genetically defined and regionally correlated to the genetic sequences in the Sand Wash Basin, to the north. Net coal is thickest in north-south oriented belts which accumulated on a coastal plain, behind west-east prograding shoreline sequences. Face cleats of Late Cretaceous age strike E-NE and W-NW in the southern and northern parts of the basin, respectively, normal to the Grand Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stresses may enhance or inhibit coal permeability in the north and south, respectively. Geopressure and hydropressure are both present in the basin with regional hydrocarbon overpressure dominant in the central part of the basin and hydropressure limited to the basin margins. The most productive gas wells in the basin are associated with structural terraces, anticlines, and/or correspond to Cameo-Wheeler-Fairfield coal-sandstone development, reflecting basement detached thrust-faulting, fracture-enhanced permeability, and reservoir heterogeneity. Depositional heterogeneties and thrusts faults isolate coal reservoirs along the Grand Hogback from the subsurface by restricting meteoric recharge and basinward flow of ground water. An evolving coalbed methane producibility model predicts that in the Piceance Basin extraordinary coalbed methane production is precluded by low permeability and by the absence of dynamic ground-water flow.

  10. Geologic and hydrologic controls on coalbed methane producibility, Williams Fork Formation, Piceance Basin, Colorado

    SciTech Connect

    Tyler, R.; Scott, A.R.; Kaiser, W.R.; Nance, H.S.; McMurry, R.G.

    1996-12-31

    Structural and depositional setting, coal rank, gas content, permeability, hydrodynamics, and reservoir heterogeneity control the producibility of coalbed methane in the Piceance Basin. The coal-rich Upper Cretaceous, Williams Fork Formation is genetically defined and regionally correlated to the genetic sequences in the Sand Wash Basin, to the north. Net coal is thickest in north-south oriented belts which accumulated on a coastal plain, behind west-east prograding shoreline sequences. Face cleats of Late Cretaceous age strike E-NE and W-NW in the southern and northern parts of the basin, respectively, normal to the Grand Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stresses may enhance or inhibit coal permeability in the north and south, respectively. Geopressure and hydropressure are both present in the basin with regional hydrocarbon overpressure dominant in the central part of the basin and hydropressure limited to the basin margins. The most productive gas wells in the basin are associated with structural terraces, anticlines, and/or correspond to Cameo-Wheeler-Fairfield coal-sandstone development, reflecting basement detached thrust-faulting, fracture-enhanced permeability, and reservoir heterogeneity. Depositional heterogeneties and thrusts faults isolate coal reservoirs along the Grand Hogback from the subsurface by restricting meteoric recharge and basinward flow of ground water. An evolving coalbed methane producibility model predicts that in the Piceance Basin extraordinary coalbed methane production is precluded by low permeability and by the absence of dynamic ground-water flow.

  11. Determination of coalbed methane potential and gas adsorption capacity in Western Kentucky coals

    USGS Publications Warehouse

    Mardon, S.M.; Takacs, K.G.; Hower, J.C.; Eble, C.F.; Mastalerz, Maria

    2006-01-01

    The Illinois Basin has not been developed for Coalbed Methane (CBM) production. It is imperative to determine both gas content and other parameters for the Kentucky portion of the Illinois Basin if exploration is to progress and production is to occur in this area. This research is part of a larger project being conducted by the Kentucky Geological Survey to evaluate the CBM production of Pennsylvanian-age western Kentucky coals in Ohio, Webster, and Union counties using methane adsorption isotherms, direct gas desorption measurements, and chemical analyses of coal and gas. This research will investigate relationships between CBM potential and petrographic, surface area, pore size, and gas adsorption isotherm analyses of the coals. Maceral and reflectance analyses are being conducted at the Center for Applied Energy Research. At the Indiana Geological Survey, the surface area and pore size of the coals will be analyzed using a Micrometrics ASAP 2020, and the CO2 isotherm analyses will be conducted using a volumetric adsorption apparatus in a water temperature bath. The aforementioned analyses will be used to determine site specific correlations for the Kentucky part of the Illinois Basin. The data collected will be compared with previous work in the Illinois Basin and will be correlated with data and structural features in the basin. Gas composition and carbon and hydrogen isotopic data suggest mostly thermogenic origin of coalbed gas in coals from Webster and Union Counties, Kentucky, in contrast to the dominantly biogenic character of coalbed gas in Ohio County, Kentucky.

  12. Water Management Strategies for Improved Coalbed Methane Production in the Black Warrior Basin

    SciTech Connect

    Pashin, Jack; McIntyre-Redden, Marcella; Mann, Steven; Merkel, David

    2013-10-31

    The modern coalbed methane industry was born in the Black Warrior Basin of Alabama and has to date produced more than 2.6 trillion cubic feet of gas and 1.6 billion barrels of water. The coalbed gas industry in this area is dependent on instream disposal of co-produced water, which ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride water. This study employed diverse analytical methods to characterize water chemistry in light of the regional geologic framework and to evaluate the full range of water management options for the Black Warrior coalbed methane industry. Results reveal strong interrelationships among regional geology, water chemistry, and gas chemistry. Coalbed methane is produced from multiple coal seams in Pennsylvanian-age strata of the Pottsville Coal Interval, in which water chemistry is influenced by a structurally controlled meteoric recharge area along the southeastern margin of the basin. The most important constituents of concern in the produced water include chlorides, ammonia compounds, and organic substances. Regional mapping and statistical analysis indicate that the concentrations of most ionic compounds, metallic substances, and nonmetallic substances correlate with total dissolved solids and chlorides. Gas is effectively produced at pipeline quality, and the only significant impurity is N{sub 2}. Geochemical analysis indicates that the gas is of mixed thermogenic-biogenic origin. Stable isotopic analysis of produced gas and calcite vein fills indicates that widespread late-stage microbial methanogenesis occurred primarily along a CO{sub 2} reduction metabolic pathway. Organic compounds in the produced water appear to have helped sustain microbial communities. Ammonia and ammonium levels increase with total dissolved solids content and appear to have played a role in late-stage microbial methanogenesis and the generation of N{sub 2}. Gas production tends to decline exponentially, whereas water production

  13. Preliminary Gulf Coast Coalbed Methane Exploration Maps: Depth to Wilcox, Apparent Wilcox Thickness and Vitrinite Reflectance

    USGS Publications Warehouse

    Barker, Charles E.; Biewick, Laura R.; Warwick, Peter D.; SanFilipo, John R.

    2000-01-01

    Strong economic controls on the viability of coalbed methane (CBM) prospects make coal geometry and coal property maps key elements in identifying sweet spots and production fairways. Therefore, this study seeks to identify the apparent prospective areas for CBM exploration in the Wilcox Group (Paleocene-Eocene) lignite and coalbeds by mapping net coal thickness, depth to coal, and coal rank (vitrinite reflectance). Economic factors are not considered in this CBM prospects study. Given the comparatively extensive gas pipeline and other production infrastructure development in the Gulf Coast Region, these factors seem less a control compared to other areas. However, open leasable public lands are minimal or nonexistent in the Gulf Coast region and access to the CBM prospects could be a problem.

  14. Organic petrography of coals from a coalbed methane test well, Ouachita Parish, Louisiana

    SciTech Connect

    Paul C. Hackley; Peter D. Warwick

    2005-07-01

    In March 2003, the U.S. Geological Survey, the Louisiana Geological Survey, and EnerVest Management Partners Ltd. participated in a Cooperative Research and Development Agreement (CRADA) to drill and core the Fairbanks Real Estate No. 359 (FRE No. 359) coalbed methane test well in Ouachita Parish, Louisiana. This effort was in support of ongoing U.S. Geological Survey investigations into the coal gas potential of the Gulf Coastal Plain. To determine possible relationships between coalbed gas content and coal composition, maceral modes were determined for 17 subsurface coal and carbonaceous shale samples cored and desorbed from the Paleocene-Eocene Wilcox Group. Similar determinations of maceral mode were made on cuttings collected from 5 non-cored coaly intervals in the overlying Eocene Sparta Sand. 22 refs., 11 figs., 3 tabs.

  15. Coalbed methane potential of the Pechora Coalfield, Timan-Pechora Basin, Russia

    SciTech Connect

    Yakutseni, V.P.; Petrova, Y.E. ); Law, B.E.; Ulmishek, G.F. )

    1996-01-01

    A comparison of the more important geologic attributes of coal beds in the coalbed methane producing regions of the United States to Permian coal beds in the Pechora Coalfield, Timan-Pechora Basin, Russia indicates a high potential for commercial coalbed methane production. Although the depositional and structural histories, as well as the age, of the coal beds in the Pechora Coalfield are different than coal beds in U.S. basins, coal quality attributes are similar. The more prospective part of the coal-bearing sequence is as thick as 1600 m and contains more than 150 coal beds that individually are as thick as 4 m. These coal beds are composed primarily of rank ranges from subbituminous to anthracite (,0.5->2.5% R[sub 0]), with the highest rank coal located near the city of Vorkuta. Published data indicates that the gas content of coals is as high as 28-35 m[sup 3]/ton, with an average value of 18 m[sup 3]/ton. About 700 MMCM of gas per year is emmitted from coal mines. Pore pressures in the coal beds are unknown, however, interbedded sandstones in some parts of the basin are overpressured. The commonly occurring problem, in mid-latitude coalbed methane well, of excessive amounts of water may be alleviated in this high-latitude coal field. We suggest that the wide-spread occurrence of permafrost in the Pechora Coalfield may form an effective barrier to down-dip water flow, thereby facilitating the dewatering state. In summary, the quality of coal beds in the Pechora Coalfield are similar to methane producing coal beds in the United States and should, therefore, be favorable for commercial rates of gas production.

  16. Coalbed methane potential of the Pechora Coalfield, Timan-Pechora Basin, Russia

    SciTech Connect

    Yakutseni, V.P.; Petrova, Y.E.; Law, B.E.; Ulmishek, G.F.

    1996-12-31

    A comparison of the more important geologic attributes of coal beds in the coalbed methane producing regions of the United States to Permian coal beds in the Pechora Coalfield, Timan-Pechora Basin, Russia indicates a high potential for commercial coalbed methane production. Although the depositional and structural histories, as well as the age, of the coal beds in the Pechora Coalfield are different than coal beds in U.S. basins, coal quality attributes are similar. The more prospective part of the coal-bearing sequence is as thick as 1600 m and contains more than 150 coal beds that individually are as thick as 4 m. These coal beds are composed primarily of rank ranges from subbituminous to anthracite (,0.5->2.5% R{sub 0}), with the highest rank coal located near the city of Vorkuta. Published data indicates that the gas content of coals is as high as 28-35 m{sup 3}/ton, with an average value of 18 m{sup 3}/ton. About 700 MMCM of gas per year is emmitted from coal mines. Pore pressures in the coal beds are unknown, however, interbedded sandstones in some parts of the basin are overpressured. The commonly occurring problem, in mid-latitude coalbed methane well, of excessive amounts of water may be alleviated in this high-latitude coal field. We suggest that the wide-spread occurrence of permafrost in the Pechora Coalfield may form an effective barrier to down-dip water flow, thereby facilitating the dewatering state. In summary, the quality of coal beds in the Pechora Coalfield are similar to methane producing coal beds in the United States and should, therefore, be favorable for commercial rates of gas production.

  17. GEOLOGIC SCREENING CRITERIA FOR SEQUESTRATION OF CO2 IN COAL: QUANTIFYING POTENTIAL OF THE BLACK WARRIOR COALBED METHANE FAIRWAY, ALABAMA

    SciTech Connect

    Jack C. Pashin; Richard E. Carroll; Richard H. Groshong Jr.; Dorothy E. Raymond; Marcella McIntyre; J. Wayne Payton

    2004-01-01

    Sequestration of CO{sub 2} in coal has potential benefits for reducing greenhouse gas emissions from the highly industrialized Carboniferous coal basins of North America and Europe and for enhancing coalbed methane recovery. Hence, enhanced coalbed methane recovery operations provide a basis for a market-based environmental solution in which the cost of sequestration is offset by the production and sale of natural gas. The Black Warrior foreland basin of west-central Alabama contains the only mature coalbed methane production fairway in eastern North America, and data from this basin provide an excellent basis for quantifying the carbon sequestration potential of coal and for identifying the geologic screening criteria required to select sites for the demonstration and commercialization of carbon sequestration technology. Coalbed methane reservoirs in the upper Pottsville Formation of the Black Warrior basin are extremely heterogeneous, and this heterogeneity must be considered to screen areas for the application of CO{sub 2} sequestration and enhanced coalbed methane recovery technology. Major screening factors include stratigraphy, geologic structure, geothermics, hydrogeology, coal quality, sorption capacity, technology, and infrastructure. Applying the screening model to the Black Warrior basin indicates that geologic structure, water chemistry, and the distribution of coal mines and reserves are the principal determinants of where CO{sub 2} can be sequestered. By comparison, coal thickness, temperature-pressure conditions, and coal quality are the key determinants of sequestration capacity and unswept coalbed methane resources. Results of this investigation indicate that the potential for CO{sub 2} sequestration and enhanced coalbed methane recovery in the Black Warrior basin is substantial and can result in significant reduction of greenhouse gas emissions while increasing natural gas reserves. Coal-fired power plants serving the Black Warrior basin in

  18. Analytical results from samples collected during coal-bed methane exploration drilling in Caldwell Parish, Louisiana

    USGS Publications Warehouse

    Warwick, Peter D.; Breland, F. Clayton; Hackley, Paul C.; Dulong, Frank T.; Nichols, Douglas J.; Karlsen, Alexander W.; Bustin, R. Marc; Barker, Charles E.; Willett, Jason C.; Trippi, Michael H.

    2006-01-01

    In 2001, and 2002, the U.S. Geological Survey (USGS) and the Louisiana Geological Survey (LGS), through a Cooperative Research and Development Agreement (CRADA) with Devon SFS Operating, Inc. (Devon), participated in an exploratory drilling and coring program for coal-bed methane in north-central Louisiana. The USGS and LGS collected 25 coal core and cuttings samples from two coal-bed methane test wells that were drilled in west-central Caldwell Parish, Louisiana. The purpose of this report is to provide the results of the analytical program conducted on the USGS/LGS samples. The data generated from this project are summarized in various topical sections that include: 1. molecular and isotopic data from coal gas samples; 2. results of low-temperature ashing and X-ray analysis; 3. palynological data; 4. down-hole temperature data; 5. detailed core descriptions and selected core photographs; 6. coal physical and chemical analytical data; 7. coal gas desorption results; 8. methane and carbon dioxide coal sorption data; 9. coal petrographic results; and 10. geophysical logs.

  19. GEOLOGIC SCREENING CRITERIA FOR SEQUESTRATION OF CO2 IN COAL: QUANTIFYING POTENTIAL OF THE BLACK WARRIOR COALBED METHANE FAIRWAY, ALABAMA

    SciTech Connect

    Jack C. Pashin; Richard E. Carroll; Richard H. Groshong, Jr.; Dorothy E. Raymond; Marcella McIntyre; J. Wayne Payton

    2003-01-01

    Sequestration of CO{sub 2} in coal has potential to reduce greenhouse gas emissions from coal-fired power plants while enhancing coalbed methane recovery. Data from more than 4,000 coalbed methane wells in the Black Warrior basin of Alabama provide an opportunity to quantify the carbon sequestration potential of coal and to develop a geologic screening model for the application of carbon sequestration technology. This report summarizes stratigraphy and sedimentation, structural geology, geothermics, hydrology, coal quality, gas capacity, and production characteristics of coal in the Black Warrior coalbed methane fairway and the implications of geology for carbon sequestration and enhanced coalbed methane recovery. Coal in the Black Warrior basin is distributed among several fluvial-deltaic coal zones in the Lower Pennsylvanian Pottsville Formation. Most coal zones contain one to three coal beds that are significant targets for coalbed methane production and carbon sequestration, and net coal thickness generally increases southeastward. Pottsville strata have effectively no matrix permeability to water, so virtually all flow is through natural fractures. Faults and folds influence the abundance and openness of fractures and, hence, the performance of coalbed methane wells. Water chemistry in the Pottsville Formation ranges from fresh to saline, and zones with TDS content lower than 10,000 mg/L can be classified as USDW. An aquifer exemption facilitating enhanced recovery in USDW can be obtained where TDS content is higher than 3,000 mg/L. Carbon dioxide becomes a supercritical fluid above a temperature of 88 F and a pressure of 1,074 psi. Reservoir temperature exceeds 88 F in much of the study area. Hydrostatic pressure gradients range from normal to extremely underpressured. A large area of underpressure is developed around closely spaced longwall coal mines, and areas of natural underpressure are distributed among the coalbed methane fields. The mobility and

  20. Optimization of enhanced coal-bed methane recovery using numerical simulation

    NASA Astrophysics Data System (ADS)

    Perera, M. S. A.; Ranjith, P. G.; Ranathunga, A. S.; Koay, A. Y. J.; Zhao, J.; Choi, S. K.

    2015-02-01

    Although the enhanced coal-bed methane (ECBM) recovery process is one of the potential coal bed methane production enhancement techniques, the effectiveness of the process is greatly dependent on the seam and the injecting gas properties. This study has therefore aimed to obtain a comprehensive knowledge of all possible major ECBM process-enhancing techniques by developing a novel 3D numerical model by considering a typical coal seam using the COMET 3 reservoir simulator. Interestingly, according to the results of the model, the generally accepted concept that there is greater CBM (coal-bed methane) production enhancement from CO2 injection, compared to the traditional water removal technique, is true only for high CO2 injection pressures. Generally, the ECBM process can be accelerated by using increased CO2 injection pressures and reduced temperatures, which are mainly related to the coal seam pore space expansion and reduced CO2 adsorption capacity, respectively. The model shows the negative influences of increased coal seam depth and moisture content on ECBM process optimization due to the reduced pore space under these conditions. However, the injection pressure plays a dominant role in the process optimization. Although the addition of a small amount of N2 into the injecting CO2 can greatly enhance the methane production process, the safe N2 percentage in the injection gas should be carefully predetermined as it causes early breakthroughs in CO2 and N2 in the methane production well. An increased number of production wells may not have a significant influence on long-term CH4 production (50 years for the selected coal seam), although it significantly enhances short-term CH4 production (10 years for the selected coal seam). Interestingly, increasing the number of injection and production wells may have a negative influence on CBM production due to the coincidence of pressure contours created by each well and the mixing of injected CO2 with CH4.

  1. The Republic of the Philippines coalbed methane assessment: based on seventeen high pressure methane adsorption isotherms

    USGS Publications Warehouse

    Flores, Romeo M.; Stricker, Gary D.; Papasin, Ramon F.; Pendon, Ronaldo R.; del Rosario, Rogelio A.; Malapitan, Ruel T.; Pastor, Michael S.; Altomea, Elmer A.; Cuaresma, Federico; Malapitan, Armando S.; Mortos, Benjamin R.; Tilos, Elizabeth N.

    2006-01-01

    Introduction: The Republic of the Philippines has some 19 coal districts that contain coal deposits ranging from Eocene to Pleistocene in age. These coal districts include: (1) Catanduanes (Eocene); (2) Cebu, Zamboanga Sibuguey, Bukidnon, Maguindanao, Sarangani, and Surigao (Oligocene to Miocene); (3) Batan Island, Masbate, Semirara (including Mindoro), and Quezon-Polilio (lower-upper Miocene); (4) Davao, Negros, and Sorsogon (middle-upper Miocene); (5) Cotabato (lower Miocene-lower Pliocene), Cagayan-Isabella, and Quirino (upper Miocene-Pliocene); (6) Sultan Kudarat (upper Miocene-Pleistocene); and (7) Samar-Leyte (lower Pliocene-Pleistocene). In general, coal rank is directly related to the age of the deposits - for example, the Eocene coal is semi-anthracite and the Pliocene-Pleistocene coal is lignite. Total coal resources in these 19 coal districts, which are compiled by the Geothermal and Coal Resources Development Division (GCRDD) of the Department of Energy of the Philippines, are estimated at a minimum of 2,268.4 million metric tonnes (MMT) (approximately 2.3 billion metric tones). The largest resource (550 MMT) is the subbituminous coal in the Semirara (including Mindoro) coal district, and the smallest (0.7 MMT) is the lignite-subbituminous coal in the Quirino coal district. The combined lignite and subbituminous coal resources, using the classification by GCRDD and including Semirara and Surigao coal districts, are about 1,899.2 MMT, which make up about 84 percent of the total coal resources of the Philippines. The remaining resources are composed of bituminous and semi-anthracite coal. The subbituminous coal of Semirara Island in the Mindoro- Semirara coal district (fig. 2) is known to contain coalbed methane (CBM), with the coal being comparable in gas content and adsorption isotherms to the coal of the Paleocene Fort Union Formation in the Powder River Basin in Wyoming, USA (Flores and others, 2005). As a consequence, the presence of CBM in the

  2. Thermodynamic Constraints on Sulfate Reduction and Methanogenesis in a Coalbed Methane Reservoir

    NASA Astrophysics Data System (ADS)

    Kirk, M. F.; Marquart, K. A.; Wilson, B. H.; Flynn, T. M.; Vinson, D. S.

    2014-12-01

    In this study we consider how commercial natural gas production could affect sulfate reduction and methanogenesis in coal-bearing sediments of the Cherokee Basin, Kansas, USA. Controls on the activity of these two groups of microbes are important to understand because their activity and interactions may influence methane formation and retention in unconventional reservoirs. During November 2013, we collected water and gas samples from 16 commercial gas wells for geochemical and microbiological analysis. Results indicate that methane in the coalbeds formed biologically and that both methanogens and sulfate reducers are present. Gas samples consisted almost entirely of methane (C1/(C2+C3) = 2638 on avg.) and the δD and δ13C of methane averaged -222‰ VSMOW and -61‰ VPDB, respectively. Archaeal sequences in our samples were nearly all classified within groups of methanogens (avg. 91%) and cultivable methanogens were present in all water samples. On average, 6% of the bacterial sequences from our samples were classified in groups of sulfate reducers and sulfate available to support their activity ranged up to 110 μM in concentration. Any interaction that occurs between these groups may be influenced by the energetics of their metabolic reactions. Thermodynamic calculations show that methanogens hold an energy advantage over sulfate reducers if dissolved methane concentrations are low. Under current conditions, methanogens see between 12 and 16 kJ mol-1 more usable free energy than sulfate reducers, if we assume a minimal methane concentration (1 μM). However, usable energy for methanogens would equal that available to sulfate reducers at methane concentrations ranging between 144 and 831 μM, well below saturation levels. Production activities that hold methane concentration below these levels, therefore, would help maintain an energy advantage for methanogens. In contrast, if production activities cause sulfate concentrations to increase, sulfate reducers would

  3. Source and Cycling of Trace Metals and Nutrients in a Microbial Coalbed Methane System

    NASA Astrophysics Data System (ADS)

    Earll, M. M.; Barnhart, E. P.; Ritter, D.; Vinson, D. S.; Orem, W. H.; Vengosh, A.; McIntosh, J. C.

    2015-12-01

    The source and cycling of trace metals and nutrients in coalbed methane (CBM) systems are controlled by both geochemical processes, such as dissolution or precipitation, and biological mediation by microbial communities. CBM production by the microbes is influenced by trace metals and macronutrients such as nitrogen (N) and phosphate (P). Previous studies have shown the importance of these nutrients to both enhance and inhibit methane production; however, it's not clear whether they are sourced from coal via in-situ biodegradation of organic matter or transported into the seams with groundwater recharge. To address this knowledge gap, trace metal and nutrient geochemistry and the organic content of solid coal and associated groundwater will be investigated across a hydrologic gradient in CBM wells in the Powder River Basin, MT. Sequential dissolution experiments (chemical extraction of organic and inorganic constituents) using 8 core samples of coal and sandstone will provide insight into the presence of trace metals and nutrients in coalbeds, the associated minerals present, and their mobilization. If significant concentrations of N, P, and trace metals are present in core samples, in-situ sourcing of nutrients by microbes is highly probable. The biogeochemical evolution of groundwater, as it relates to trace metal and nutrient cycling by microbial consortia, will be investigated by targeting core-associated coal seams from shallow wells in recharge areas to depths of at least 165 m and across a 28 m vertical profile that include overburden, coal, and underburden. If microbial-limiting trace metals and nutrients are transported into coal seams with groundwater recharge, we would expect to see higher concentrations of trace metals and nutrients in recharge areas compared to deeper coalbeds. The results of this study will provide novel understanding of where trace metals and nutrients are sourced and how they are cycled in CBM systems.

  4. Composite geochemical database for coalbed methane produced water quality in the Rocky Mountain region.

    PubMed

    Dahm, Katharine G; Guerra, Katie L; Xu, Pei; Drewes, Jörg E

    2011-09-15

    Coalbed methane (CBM) or coalbed natural gas (CBNG) is an unconventional natural gas resource with large reserves in the United States (US) and worldwide. Production is limited by challenges in the management of large volumes of produced water. Due to salinity of CBM produced water, it is commonly reinjected into the subsurface for disposal. Utilization of this nontraditional water source is hindered by limited knowledge of water quality. A composite geochemical database was created with 3255 CBM wellhead entries, covering four basins in the Rocky Mountain region, and resulting in information on 64 parameters and constituents. Database water composition is dominated by sodium bicarbonate and sodium chloride type waters with total dissolved solids concentrations of 150 to 39,260 mg/L. Constituents commonly exceeding standards for drinking, livestock, and irrigation water applications were total dissolved solids (TDS), sodium adsorption ratio (SAR), temperature, iron, and fluoride. Chemical trends in the basins are linked to the type of coal deposits, the rank of the coal deposits, and the proximity of the well to fresh water recharge. These water composition trends based on basin geology, hydrogeology, and methane generation pathway are relevant to predicting water quality compositions for beneficial use applications in CBM-producing basins worldwide. PMID:21790201

  5. Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

    PubMed Central

    2016-01-01

    The draft genome sequence of Pseudomonas stutzeri strain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

  6. Coal and coalbed methane resources of Cretaceous rocks of the Black Mesa Basin, northeastern Arizona

    SciTech Connect

    Nations, J.D.; Haven, H.W.; Swift, R.L.

    1995-06-01

    Cretaceous rocks of the Black Mesa basin of northeastern Arizona were deposited from Late Cenomanian to Santonian time near the western depositional limit of the transgressive-regressive Greenhorn and Niobrara cyclothems. Coal-bearing rocks of the sequence (including the Dakota Formation, Toreva Formation and Wepo Formation) are preserved in the Black Mesa structural basin of Laramide age. These rocks of the Black Mesa basin are the object of an NSF-sponsored research project to evaluate their coal resources and potential for coalbed methane occurrence. Forty-five measured sections and descriptions of Cretaceous rocks around the eastern margin of the basin have been incorporated into a data base in the software program LOGGER, and have been used to construct a series of stratigraphic cross-sections across the basin using the software program MacSection. These include coal beds and carbonaceous shales that are potential sources of methane as well as reservoirs, and sandstone bodies that are potential secondary reservoirs of methane (and possibly petroleum hydrocarbons from the Mancos Shale). In order to trace the facies changes between measured sections, aerial videography and 35 mm slides have been taken along the entire eastern margin of Black Mesa, a distance of 70 miles. These were digitized to provide detailed lithofacies analyses of the stratigraphic sections along the north-trending cliff line. Trends of thickness variations within these facies are interpreted from isopach maps and known shoreline trends, in order to predict the areas of greatest probability of coalbed methane generation and accumulation. These predictions are also based on the locations of anticlinal and monoclinal fold axes where they cross the thickest coal trends, due to likely enhancement of permeability by cleat and butt fractures in the coal and shale reservoir rocks.

  7. Correlation of producing Fruitland Formation coals within the western outcrop and coalbed methane leakage on the Southern Ute Reservation

    SciTech Connect

    Carroll, Christopher J.; Mathews, Stephanie; Wickman, Barbara

    2000-07-07

    The Colorado Geological Survey and Southern Ute Indian Tribe proposed to determine the cause of several gas seeps which are occurring on the western outcrop of the coalbed methane producing Fruitland Formation on the Southern Ute Indian Reservation. Correlation between outcrop coals and subsurface coals was necessary to determine seep source in the northern part of the study area. Subsurface studies include structure and net coal isopach maps, stratigraphy was cross-sections, production maps, and a production database. Detailed coal stratigraphy was correlated through production wells near the outcrop region. These maps and cross-sections were correlated to new surface outcrop maps generated by the Colorado, Geological Survey and the Southern Ute Division of Energy Resources. Methane gas seepage has been noted historically within the study area. The total investigation may help determine if gas seepage is natural, a result of coalbed methane development, or some combination of the above.

  8. Modeling Coal Matrix Shrinkage and Differential Swelling with CO2 Injection for Enhanced Coalbed Methane Recovery and Carbon Sequestration Applications

    SciTech Connect

    L. J. Pekot; S. R. Reeves

    2002-03-31

    Matrix shrinkage and swelling can cause profound changes in porosity and permeability of coalbed methane reservoirs during depletion or when under CO{sub 2} injection processes, with significant implication for primary or enhanced methane recovery. Two models that are used to describe these effects are discussed. The first was developed by Advanced Resources International (ARI) and published in 1990 by Sawyer, et al. The second model was published by Palmer and Mansoori in 1996. This paper shows that the two provide equivalent results for most applications. However, their differences in formulation cause each to have relative advantages and disadvantages under certain circumstances. Specifically, the former appears superior for undersaturated coalbed methane reservoirs while the latter would be better if a case is found where matrix swelling is strongly disproportional to gas concentration. Since its presentation in 1996, the Palmer and Mansoori model has justifiably received much critical praise. However, the model developed by ARI for the COMET reservoir simulation program has been in use since 1990, and has significant advantages in certain settings. A review of data published by Levine in 1996 reveals that carbon dioxide causes a greater degree of coal matrix swelling compared to methane, even when measured on a unit of concentration basis. This effect is described in this report as differential swelling. Differential swelling may have important consequences for enhanced coalbed methane and carbon sequestration projects. To handle the effects of differential swelling, an extension to the matrix shrinkage and swelling model used by the COMET simulator is presented and shown to replicate the data of Levine. Preliminary field results from a carbon dioxide injection project are also presented in support of the extended model. The field evidence supports that considerable changes to coal permeability occur with CO{sub 2} injection, with significant implication for

  9. Dewatering systems and techniques for coalbed methane wells. Volume 1. Final report

    SciTech Connect

    McGinnis, N.

    1983-08-01

    The production of methane from most coalbeds requires the removal of the water to reduce the hydrostatic pressure and increase the relative permeability to gas flow. This study provides an evaluation of contemporary oil and gas pumping systems for this application. The systems evaluated are sucker rod (beam pumping unit), electric submersible, hydraulic jet, hydraulic piston, plunger lift, and gas lift. Ten well systems were defined to normalize the basis of comparison for the fluid-powered systems. The systems were evaluated for pumping 15 and 200 barrels per day (bpd) of water from depths of 1,000, 2,500, 4,000, and 8,000 feet. Comparisons were developed for equipment, installation, and OandM costs for each system, and combinations of systems when smaller units are used to replace initial installations later in the well life. Subjective rankings were also developed using 17 criteria to reflect individual field situations and environments.

  10. Numerical Simulation of CO2 Flooding of Coalbed Methane Considering the Fluid-Solid Coupling Effect.

    PubMed

    Liu, Jianjun; Li, Guang; Zhang, Yue

    2016-01-01

    CO2 flooding of coalbed methane (CO2-ECBM) not only stores CO2 underground and reduces greenhouse gas emissions but also enhances the gas production ratio. This coupled process involves multi-phase fluid flow and coal-rock deformation, as well as processes such as competitive gas adsorption and diffusion from the coal matrix into fractures. A dual-porosity medium that consists of a matrix and fractures was built to simulate the flooding process, and a mathematical model was used to consider the competitive adsorption, diffusion and seepage processes and the interaction between flow and deformation. Due to the effects of the initial pressure and the differences in pressure variation during the production process, permeability changes caused by matrix shrinkage were spatially variable in the reservoir. The maximum value of permeability appeared near the production well, and the degree of rebound decreased with increasing distance from the production well.

  11. Numerical Simulation of CO2 Flooding of Coalbed Methane Considering the Fluid-Solid Coupling Effect

    PubMed Central

    Liu, Jianjun; Li, Guang; Zhang, Yue

    2016-01-01

    CO2 flooding of coalbed methane (CO2-ECBM) not only stores CO2 underground and reduces greenhouse gas emissions but also enhances the gas production ratio. This coupled process involves multi-phase fluid flow and coal-rock deformation, as well as processes such as competitive gas adsorption and diffusion from the coal matrix into fractures. A dual-porosity medium that consists of a matrix and fractures was built to simulate the flooding process, and a mathematical model was used to consider the competitive adsorption, diffusion and seepage processes and the interaction between flow and deformation. Due to the effects of the initial pressure and the differences in pressure variation during the production process, permeability changes caused by matrix shrinkage were spatially variable in the reservoir. The maximum value of permeability appeared near the production well, and the degree of rebound decreased with increasing distance from the production well. PMID:27031096

  12. Numerical Simulation of CO2 Flooding of Coalbed Methane Considering the Fluid-Solid Coupling Effect.

    PubMed

    Liu, Jianjun; Li, Guang; Zhang, Yue

    2016-01-01

    CO2 flooding of coalbed methane (CO2-ECBM) not only stores CO2 underground and reduces greenhouse gas emissions but also enhances the gas production ratio. This coupled process involves multi-phase fluid flow and coal-rock deformation, as well as processes such as competitive gas adsorption and diffusion from the coal matrix into fractures. A dual-porosity medium that consists of a matrix and fractures was built to simulate the flooding process, and a mathematical model was used to consider the competitive adsorption, diffusion and seepage processes and the interaction between flow and deformation. Due to the effects of the initial pressure and the differences in pressure variation during the production process, permeability changes caused by matrix shrinkage were spatially variable in the reservoir. The maximum value of permeability appeared near the production well, and the degree of rebound decreased with increasing distance from the production well. PMID:27031096

  13. Drunkard's wash project: Coalbed methane production from Ferron coals in east-central Utah

    SciTech Connect

    Lemarre, R.A. ); Burns, T.D. )

    1996-01-01

    The Drunkard's Wash Project produces dry, coalbed methane gas from coals within the Ferron Sandstone Member of the Mancos Shale. The project covers 120,000 acres on the western flank of the San Rafael Uplift in east-central Utah. Gas was first produced into the sales line in January 1993. The field is being developed on 160 acre spacing with 73 wells currently producing 32.2 MMCFD for an average of 437 MCFD/well. Thirty three of those wells have been producing for 32 months and now average 637 MCFD/well. Most of the wells show a classic coalbed methane negative decline curve with increasing gas rates as the reservoir pressure declines due to production of water. Daily water production is 14,500 BPD, for an average of 199 BWPD/well. Total coal thickness ranges from 7 ft. to 48 ft., with an average of 24 ft. The coals occur in 3 to 6 seams at depths of 1350 to 2450 ft. The coal rank is high volatile A B bituminous. We can not yet see a correlation between total coal thickness and current production. All wells are cased and hydraulically stimulated and most require pumping units to handle the large volumes of water. However, 22 wells do not require pumps and flow unassisted to the surface. The structure consists of monoclinal westward dip. A thin tonstein layer in the bottom coal seam serves as an excellent datum for mapping. Enhanced production is encountered along a southwest-plunging nose that probably formed additional fracture permeability within the coals. Northeast-trending reverse faults with small displacement appear to compartmentalize the reservoir. The Ferron coals were deposited in a river-dominated deltaic system that prograded to the east and southeast during Turonian-Coniacian (Upper Cretaceous) time. The Ferron Sandstone Member represents an eastward-thinning elastic wedge that was deposited during regression of the Western Interior Cretaceous seaway.

  14. Drunkard`s wash project: Coalbed methane production from Ferron coals in east-central Utah

    SciTech Connect

    Lemarre, R.A.; Burns, T.D.

    1996-12-31

    The Drunkard`s Wash Project produces dry, coalbed methane gas from coals within the Ferron Sandstone Member of the Mancos Shale. The project covers 120,000 acres on the western flank of the San Rafael Uplift in east-central Utah. Gas was first produced into the sales line in January 1993. The field is being developed on 160 acre spacing with 73 wells currently producing 32.2 MMCFD for an average of 437 MCFD/well. Thirty three of those wells have been producing for 32 months and now average 637 MCFD/well. Most of the wells show a classic coalbed methane negative decline curve with increasing gas rates as the reservoir pressure declines due to production of water. Daily water production is 14,500 BPD, for an average of 199 BWPD/well. Total coal thickness ranges from 7 ft. to 48 ft., with an average of 24 ft. The coals occur in 3 to 6 seams at depths of 1350 to 2450 ft. The coal rank is high volatile A&B bituminous. We can not yet see a correlation between total coal thickness and current production. All wells are cased and hydraulically stimulated and most require pumping units to handle the large volumes of water. However, 22 wells do not require pumps and flow unassisted to the surface. The structure consists of monoclinal westward dip. A thin tonstein layer in the bottom coal seam serves as an excellent datum for mapping. Enhanced production is encountered along a southwest-plunging nose that probably formed additional fracture permeability within the coals. Northeast-trending reverse faults with small displacement appear to compartmentalize the reservoir. The Ferron coals were deposited in a river-dominated deltaic system that prograded to the east and southeast during Turonian-Coniacian (Upper Cretaceous) time. The Ferron Sandstone Member represents an eastward-thinning elastic wedge that was deposited during regression of the Western Interior Cretaceous seaway.

  15. Identifying well contamination through the use of 3-D fluorescence spectroscopy to classify coalbed methane produced water.

    PubMed

    Dahm, Katharine G; Van Straaten, Colette M; Munakata-Marr, Junko; Drewes, Jörg E

    2013-01-01

    Production of unconventional gas resources commonly requires the use of hydraulic fracturing and chemical production well additives. Concern exists for the use of chemical compounds in gas wells due to the risk of groundwater contamination. This study focuses on a proposed method of identifying groundwater contamination from gas production. The method focuses on the classification of naturally occurring organic signatures of coalbed methane (CBM) produced water compared to anthropogenic organic compounds. The 3-D fluorescence excitation-emission matrix (EEM) spectra of coalbed methane produced water samples revealed four peaks characteristic of coalbed methane produced water: Peak P (aromatic proteins region), Peak M(1) (microbial byproducts region), Peak M(2) (microbial byproducts region), and Peak H (humic acid-like region). Peak H is characteristic of the coal-water equilibria present in all basins, while peaks P and M(2) correlate with microbial activity in basins with biogenic methane generation pathways. Anthropogenic well additives produce EEM signatures with notable flooding of peaks P, M(1), M(2), and H, relatively higher overall fluorescence intensity, and slightly higher DOC concentrations. Fluorescence spectroscopy has the potential to be used in conjunction with groundwater contamination studies to determine if detected organic compounds originate from naturally occurring sources or well production additives.

  16. Coal-Bed Methane Water Effects on Dill and Its Essential Oils.

    PubMed

    Poudyal, Shital; Zheljazkov, Valtcho D; Cantrell, Charles L; Kelleners, Thijs

    2016-03-01

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic method of methane extraction. The water that is pumped out is known as "coal-bed methane water" (CBMW), which is high in sodium and other salts. In the past 25 yr, the United States has seen a 16-fold increase in the production of coal bed methane gas, and trillions of cubic meters are yet to be extracted. There is no sustainable disposal method for CBMW, and there are very few studies investigating the effects of this water on plants and their secondary metabolites and on soil properties. This study was conducted to determine the effects of CBMW on soil chemical properties and on the biomass and essential oil yield and composition of dill ( L.). This crop was grown in a greenhouse and was subjected to different levels of CBMW treatment: tap water only; 25% CBMW, 75% tap water; 50% CBMW, 50% tap water; 75% CBMW, 25% tap water; and 100% CBMW. The major dill oil constituents, limonene and α-phellandrene, were not affected by the treatments; however, the concentration of dill ether increased with increasing CBMW levels, whereas the concentration of carvone decreased. In soil, sodium level significantly increased with increasing level of treatment, but pH and cation exchange capacity were not much affected. Coal bed methane water could be used for irrigation of dill for one growing season, but longer-term studies may be needed to clarify the long-term effects on soil and plant. PMID:27065421

  17. Coalbed methane, Cook Inlet, south-central Alaska: A potential giant gas resource

    USGS Publications Warehouse

    Montgomery, S.L.; Barker, C.E.

    2003-01-01

    Cook Inlet Basin of south-central Alaska is a forearc basin containing voluminous Tertiary coal deposits with sufficient methane content to suggest a major coalbed gas resource. Coals ranging in thickness from 2 to 50 ft (0.6 to 15 m) and in gas content from 50 to 250 scf/ton (1.6 to 7.8 cm2/g) occur in Miocene-Oligocene fluvial deposits of the Kenai Group. These coals have been identified as the probable source of more than 8 tcf gas that has been produced from conventional sandstone reservoirs in the basin. Cook Inlet coals can be divided into two main groups: (1) those of bituminous rank in the Tyonek Formation that contain mainly thermogenic methane and are confined to the northeastern part of the basin (Matanuska Valley) and to deep levels elsewhere; and (2) subbituminous coals at shallow depths (<5000 ft [1524 m]) in the Tyonek and overlying Beluga formations, which contain mainly biogenic methane and cover most of the central and southern basin. Based on core and corrected cuttings-desorption analyses, gas contents average 230 scf/ton (7.2 cm2/g) for bituminous coals and 80 scf/ton (2.5 cm2/g) for subbituminous coals. Isotherms constructed for samples of both coal ranks suggest that bituminous coals are saturated with respect to methane, whereas subbituminous coals at shallow depths along the eroded west-central basin margin are locally unsaturated. A preliminary estimate of 140 tcf gas in place is derived for the basin.

  18. Iodine-129 and Chlorine-36 as Tracers of Hydrodynamic Processes in Coalbed Methane Systems: Environmental Implications

    NASA Astrophysics Data System (ADS)

    Snyder, G. T.; Riese, W. R.; Fehn, U.; Moran, J. E.; Pelzmann, W. L.

    2003-12-01

    Models which predict the response of coalbed methane systems to commercial exploitation generally assume that the coals host groundwaters which belong to a dynamic through-flowing system. For this to occur, fluid migration must be focused along localized fractures and cleat structures. This situation can facilitate enhanced methane recovery through carbon dioxide reinjection, but may also lead to premature breakthrough of the injected gasses to production wells, thereby leaving stranded resources behind in the reservoir. Water encroachment from surrounding areas may also occur and create problems. The emerging alternative view of coal-hosted hydrodynamic systems is that they are essentially static systems which host connate formation waters. Fluid migration is precluded by the presence of gas and its influence on relative permeability in the fractures and cleats. While the removal of these waters will produce local drawdown and allow production of the adsorbed methane, it also represents extraction of a limited and non-renewable hydrologic resource. Understanding which of these hydrodynamic environments is present is critical if informed decisions regarding resource development and exploitation are to be made. We used the 129I and 36Cl systems as indicators of the migration history of fluids in the Fruitland Formation coals in the San Juan Basin of Colorado and New Mexico. Because of their long half-lives (15.7 Myr and 0.3 Myr respectively ) these cosmogenic isotopes provide useful constraints on the processes which have occurred since the peat deposits were buried 73 million years ago, and can provide direct evidence on the validity of hydrodynamic models. Our results indicate several isotopically distinct sets of waters are apparent within coals of the Fruitland Formation. The infiltration of recent surface waters is clearly limited to the uplifted basin margins, indicated by the similarity of 129I/I ratios, 36Cl/Cl ratios, δ D, and δ 18O signatures to those of

  19. The current state of coalbed methane development in the United Kingdom

    SciTech Connect

    Sharman, P.

    1997-12-31

    Much of the early work on coalbed methane exploitation was carried out in the US. Considerable quantities of gas are currently being extracted from the San Juan and Black Warrior Basins. Based on this experience there is considerable interest in using the technology in Western and Eastern Europe. This is against the background of a declining European production of conventional deep-mined coal, due to difficult geological and market conditions. Nevertheless Europe has considerable reserves of deep coal, unsuitable for conventional mining, many of which contain large amounts of in situ methane. This paper outlines the work that has been carried out in the UK. There have been considerable problems, not least of which has been the far lower permeability of European coals, compared with US ones. Nevertheless many lessons have been learned and there is now a far better understanding of the potential for CBM production in the UK. While the paper concentrates on UK conditions the results are of relevance throughout Europe and indeed in other continents.

  20. Cleats and their relation to geologic lineaments and coalbed methane potential in Pennsylvanian coals in Indiana

    USGS Publications Warehouse

    Solano-Acosta, W.; Mastalerz, Maria; Schimmelmann, A.

    2007-01-01

    Cleats and fractures in Pennsylvanian coals in southwestern Indiana were described, statistically analyzed, and subsequently interpreted in terms of their origin, relation to geologic lineaments, and significance for coal permeability and coalbed gas generation and storage. These cleats can be interpreted as the result of superimposed endogenic and exogenic processes. Endogenic processes are associated with coalification (i.e., matrix dehydration and shrinkage), while exogenic processes are mainly associated with larger-scale phenomena, such as tectonic stress. At least two distinct generations of cleats were identified on the basis of field reconnaissance and microscopic study: a first generation of cleats that developed early on during coalification and a second generation that cuts through the previous one at an angle that mimics the orientation of the present-day stress field. The observed parallelism between early-formed cleats and mapped lineaments suggests a well-established tectonic control during early cleat formation. Authigenic minerals filling early cleats represent the vestiges of once open hydrologic regimes. The second generation of cleats is characterized by less prominent features (i.e., smaller apertures) with a much less pronounced occurrence of authigenic mineralization. Our findings suggest a multistage development of cleats that resulted from tectonic stress regimes that changed orientation during coalification and basin evolution. The coals studied are characterized by a macrocleat distribution similar to that of well-developed coalbed methane basins (e.g., Black Warrior Basin, Alabama). Scatter plots and regression analyses of meso- and microcleats reveal a power-law distribution between spacing and cleat aperture. The same distribution was observed for fractures at microscopic scale. Our observations suggest that microcleats enhance permeability by providing additional paths for migration of gas out of the coal matrix, in addition to

  1. Drilling and Testing the DOI041A Coalbed Methane Well, Fort Yukon, Alaska

    USGS Publications Warehouse

    Clark, Arthur; Barker, Charles E.; Weeks, Edwin P.

    2009-01-01

    The need for affordable energy sources is acute in rural communities of Alaska where costly diesel fuel must be delivered by barge or plane for power generation. Additionally, the transport, transfer, and storage of fuel pose great difficulty in these regions. Although small-scale energy development in remote Arctic locations presents unique challenges, identifying and developing economic, local sources of energy remains a high priority for state and local government. Many areas in rural Alaska contain widespread coal resources that may contain significant amounts of coalbed methane (CBM) that, when extracted, could be used for power generation. However, in many of these areas, little is known concerning the properties that control CBM occurrence and production, including coal bed geometry, coalbed gas content and saturation, reservoir permeability and pressure, and water chemistry. Therefore, drilling and testing to collect these data are required to accurately assess the viability of CBM as a potential energy source in most locations. In 2004, the U.S. Geological Survey (USGS) and Bureau of Land Management (BLM), in cooperation with the U.S. Department of Energy (DOE), the Alaska Department of Geological and Geophysical Surveys (DGGS), the University of Alaska Fairbanks (UAF), the Doyon Native Corporation, and the village of Fort Yukon, organized and funded the drilling of a well at Fort Yukon, Alaska to test coal beds for CBM developmental potential. Fort Yukon is a town of about 600 people and is composed mostly of Gwich'in Athabascan Native Americans. It is located near the center of the Yukon Flats Basin, approximately 145 mi northeast of Fairbanks.

  2. Integrated exploration strategy for locating areas capable of high gas rate cavity completion in coalbed methane reservoirs

    SciTech Connect

    Klawitter, A.L.; Hoak, T.E.; Decker, A.D.

    1995-10-01

    In 1993, the San Juan Basin accounted for approximately 605 Bcf of the 740 Bcf of all coalbed gas produced in the United States. The San Juan {open_quotes}cavitation fairway{close_quotes} in which production occurs in open-hole cavity completions, is responsible for over 60% of all U.S. coalbed methane production. Perhaps most striking is the fact that over 17,000 wells had penetrated the Fruitland formation in the San Juan Basin prior to recognition of the coalbed methan potential. To understand the dynamic cavity fairway reservoir in the San Juan Basin, an exploration rationale for coalbed methan was developed that permits a sequential reduction in total basin exploration area based on four primary exploration criteria. One of the most significant criterion is the existence of thick, thermally mature, friable coals. A second criterion is the existence of fully gas-charged coals. Evaluation of this criterion requires reservoir geochemical data to delineate zones of meteoric influx where breaching has occurred. A third criterion is the presence of adequate reservoir permeability. Natural fracturing in coals is due to cleating and tectonic processes. Because of the general relationship between coal cleating and coal rank, coal cleating intensity can be estimated by analysis of regional coal rank maps. The final criterion is determining whether natural fractures are open or closed. To make this determination, remote sensing imagery interpretation is supported by ancillary data compiled from regional tectonic studies. Application of these four criteria to the San Juan Basin in a heuristic, stepwise process resulted in an overall 94% reduction in total basin exploration area. Application of the first criterion reduced the total basin exploration area by 80%. Application of the second criterion further winnows this area by an addition 9%. Application of the third criterion reduces the exploration area to 6% of the total original exploration area.

  3. Permo-Carboniferous coal: A major target for coalbed methane exploration in China

    SciTech Connect

    Murray, D.K.

    1996-12-31

    The People`s Republic of China is the largest producer of coal in the world, the most populous country, and is experiencing a significant growth in GNP. Three-fourths of China`s energy requirements are met by burning coal. At least 80 percent of the produced coal is Permo-Carboniferous, ranging in rank from bituminous to anthracite ({open_quotes}hardcoal{close_quotes}), and is mined from underground facilities that typically are very gas-prone. The coal resources of China, estimated at 7.7 to 12.1 trillion tons, are among the largest in the world. Much of this in-place resource consists of Permo-Carboniferous hardcoal. The resource base of coalbed methane (CBM) in China, variously estimated at 1,000 to 2,800 Tcf, may be the world`s largest. A significant portion of this valuable energy source is believed to be contained in Permo-Carboniferous coals. The government of China is seeking international technology and investment to develop and utilize CBM, which is expected to improve the nation`s economy, increase mine safety, and reduce the wasteful and polluting emissions of methane from coal mines. In particular, the government is emphasizing development of CBM in the North China Basin region, the locale of the most abundant and highest rank Permo-Carboniferous coals. An encouraging aspect of cooperative Sino-American efforts is the recent discovery of significant flows of methane from permeable anthracite reservoirs in Henan and Shanxi Provinces. These two discoveries are believed to be the first in the world from anthracites.

  4. Permo-Carboniferous coal: A major target for coalbed methane exploration in China

    SciTech Connect

    Murray, D.K. )

    1996-01-01

    The People's Republic of China is the largest producer of coal in the world, the most populous country, and is experiencing a significant growth in GNP. Three-fourths of China's energy requirements are met by burning coal. At least 80 percent of the produced coal is Permo-Carboniferous, ranging in rank from bituminous to anthracite ([open quotes]hardcoal[close quotes]), and is mined from underground facilities that typically are very gas-prone. The coal resources of China, estimated at 7.7 to 12.1 trillion tons, are among the largest in the world. Much of this in-place resource consists of Permo-Carboniferous hardcoal. The resource base of coalbed methane (CBM) in China, variously estimated at 1,000 to 2,800 Tcf, may be the world's largest. A significant portion of this valuable energy source is believed to be contained in Permo-Carboniferous coals. The government of China is seeking international technology and investment to develop and utilize CBM, which is expected to improve the nation's economy, increase mine safety, and reduce the wasteful and polluting emissions of methane from coal mines. In particular, the government is emphasizing development of CBM in the North China Basin region, the locale of the most abundant and highest rank Permo-Carboniferous coals. An encouraging aspect of cooperative Sino-American efforts is the recent discovery of significant flows of methane from permeable anthracite reservoirs in Henan and Shanxi Provinces. These two discoveries are believed to be the first in the world from anthracites.

  5. Geologic and hydrologic controls on coalbed methane: Sand wash basin, Colorado and Wyoming. Topical report, August 1, 1991-April 30, 1993

    SciTech Connect

    Kaiser, W.R.; Scott, A.R.; Hamilton, D.S.; Tyler, R.; McMurry, R.G.

    1993-08-01

    Contents: tectonic evolution, stratigraphic setting, and coal fracture patterns of the sand wash basin; stratigraphy and coal occurrence of the upper cretaceous mesaverde group, sand wash basin; coal rank, gas content, and composition and origin of coalbed gases, mesaverde group, sand wash basin; hydrologic setting of the upper mesaverde group, sand wash basin; stratigraphy and coal occurrence of the paleocene fort union formation, sand wash basin; coal rank, gas content, and composition and origin of coalbed gases, fort union formation, sand wash basin; hydrologic setting of the fort union formation, sand wash basin; and resources and producibility of coalbed methane in the sand wash basin.

  6. The central and northern Appalachian Basin-a frontier region for coalbed methane development

    USGS Publications Warehouse

    Lyons, P.C.

    1998-01-01

    The Appalachian basin is the world's second largest coalbed-methane (CBM) producing basin. It has nearly 4000 wells with 1996 annual production at 147.8 billion cubic feet (Bcf). Cumulative CBM production is close to 0.9 trillion cubic feet (Tcf). The Black Warrior Basin of Alabama in the southern Appalachian basin (including a very minor amount from the Cahaba coal field) accounts for about 75% of this annual production and about 75% of the wells, and the remainder comes from the central and northern Appalachian basin. The Southwest Virginia coal field accounts for about 95% of the production from the central and northern parts of the Appalachian basin. Production data and trends imply that several of the Appalachian basin states, except for Alabama and Virginia, are in their infancy with respect to CBM development. Total in-place CBM resources in the central and northern Appalachian basin have been variously estimated at 66 to 76 trillion cubic feet (Tcf), of which an estimated 14.55 Tcf (~ 20%) is technically recoverable according to a 1995 U.S. Geological Survey assessment. For comparison in the Black Warrior basin of the 20 Tcf in-place CBM resources, 2.30 Tcf (~ 12%) is technically recoverable. Because close to 0.9 Tcf of CBM has already been produced from the Black Warrior basin and the proved reserves are about 0.8 Tcf for 1996 [Energy Information Administration (EIA), 1997]. U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves, 1996 Annual Report. U.S. Department of Energy DOE/EIA-0216(96), 145 pp.], these data imply that the central and northern Appalachian basin could become increasingly important in the Appalachian basin CBM picture as CBM resources are depleted in the southern Appalachian basin (Black Warrior Basin and Cahaba Coal Field). CBM development in the Appalachian states could decrease the eastern U.S.A.'s dependence on coal for electricity. CBM is expected to provide over the next few decades a virtually untapped source of

  7. Estimation of different coal compressibilities of coalbed methane reservoirs under replicated in situ condition

    NASA Astrophysics Data System (ADS)

    Liu, Shimin

    Studies completed recently have shown that desorption of methane results in a change in the matrix volume of coal thus altering the permeability of, and production rates from, coalbed methane (CBM) reservoirs. An accurate estimation of different coal compressibilities is, therefore, critical in CBM operations in order to model and project gas production rates. Furthermore, a comprehensive knowledge of the dynamic permeability helps in understanding the unique feature of CBM production, an initial negative gas decline rate. In this study, different coal compressibility models were developed based on the assumption that the deformation of a depleting coalbed is limited to the vertical direction, that is, the reservoir is under uniaxial strain conditions. Simultaneously, experimental work was carried out replicating these conditions. The results showed that the matrix volumetric strain typically follows the Langmuir-type relationship. The agreement between the experimental results and those obtained using the proposed model was good. The proposed volumetric strain model successfully isolated the sorption-induced strain from the strain resulting from mechanical compression. It, therefore, provides a technique to integrate the sorption-induced strain alone into different analytical permeability models. The permeability variation of coal with a decrease in pore pressure under replicated in situ stress/strain conditions was measured. The results showed that decreasing pore pressure resulted in a significant decrease in horizontal stress and increased permeability. The permeability increased non-linearly with decreasing pore pressure, with a small increase in the high pressure range, increasing progressively as the pressure dropped below a certain value. The experimental results were also used to test the proposed coupled sorption-induced strain model and several analytical permeability models. One of the commonly used models overestimated the permeability increase between

  8. Evaluation of the relative importance of coalbed reservoir parameters for prediction of methane inflow rates during mining of longwall development entries

    NASA Astrophysics Data System (ADS)

    Karacan, C. Ö.

    2008-09-01

    This study presents a reservoir modeling approach to investigate the relative effects of different coalbed parameters on the migration of methane into development entries. A base coalbed reservoir model of a three-entry development section, where grids were dynamically controlled to simulate the advance of mining at a constant section advance rate, was created and calibrated for a Pittsburgh Coalbed mine in the Southwestern Pennsylvania section of the Northern Appalachian Basin. The values of coalbed parameters were varied to evaluate their effects on predicted methane emissions for various development distances. The results of these parametric simulations were then used to derive linear expressions relating these parameters to methane emissions into the workings. These models were analyzed to assess their significance and adequacy for predictive purposes. This work shows that coupling reservoir simulations with linear modeling yield a technique that can be applicable to different coalbeds. The reservoir parameters used by the linear models (coalbed thickness, pressure, sorption time constant, Langmuir parameters, permeability) can be determined by running relatively simple laboratory tests, such as adsorption equilibrium and permeability determination, on coal samples obtained either from the mining operation or from the exploratory boreholes drilled ahead of mining.

  9. Anomaly Identification from Super-Low Frequency Electromagnetic Data for the Coalbed Methane Detection

    NASA Astrophysics Data System (ADS)

    Zhao, S. S.; Wang, N.; Hui, J.; Ye, X.; Qin, Q.

    2016-06-01

    Natural source Super Low Frequency(SLF) electromagnetic prospecting methods have become an increasingly promising way in the resource detection. The capacity estimation of the reservoirs is of great importance to evaluate their exploitation potency. In this paper, we built a signal-estimate model for SLF electromagnetic signal and processed the monitored data with adaptive filter. The non-normal distribution test showed that the distribution of the signal was obviously different from Gaussian probability distribution, and Class B instantaneous amplitude probability model can well describe the statistical properties of SLF electromagnetic data. The Class B model parameter estimation is very complicated because its kernel function is confluent hypergeometric function. The parameters of the model were estimated based on property spectral function using Least Square Gradient Method(LSGM). The simulation of this estimation method was carried out, and the results of simulation demonstrated that the LGSM estimation method can reflect important information of the Class B signal model, of which the Gaussian component was considered to be the systematic noise and random noise, and the Intermediate Event Component was considered to be the background ground and human activity noise. Then the observation data was processed using adaptive noise cancellation filter. With the noise components subtracted out adaptively, the remaining part is the signal of interest, i.e., the anomaly information. It was considered to be relevant to the reservoir position of the coalbed methane stratum.

  10. Economic feasibility of drilling horizontal wells in a shallow high permeability coalbed methane reservoir

    NASA Astrophysics Data System (ADS)

    Doghor, Kesiena Gavin

    Coalbed methane (CBM) reservoirs have emerged as an important source of natural gas production. However, the choice of drilling configuration employed differs from basin to basin. The Powder River Basin coal seams shallow nature is believed to favor the current vertical well configuration. Horizontal well drilling in CBM reservoirs has been studied in deep and thick coal seams like the Appalachian and Cherokee Basins in USA, but little work has been done in shallow CBM reservoirs like those of the Powder River Basin. The objective of this thesis is to use a reservoir simulator and economic analysis to study the economic feasibility of drilling horizontal wells in shallow CBM reservoirs such as the CX field Monarch Coal seam of the Powder River Basin. A dual porosity reservoir model was built and historical production was matched. The resulting simulator was used to run different configurations of vertical and horizontal wells. Economic analysis was then performed on the simulated productions to determine the optimal drilling strategy. Additional cases of different permeability values and thicknesses were also considered. The results show that horizontal wells would not be economical when compared to vertical wells in shallow coal seams. The results of this work were based on current natural gas prices and drilling and operational cost.

  11. INJECTION INTO COAL SEAMS FOR SIMULTANEOUS CO2 MITIGATION AND ENHANCED RECOVERY OF COALBED METHANE

    SciTech Connect

    Francis M. Carlson; Charles G. Mones; Lyle A. Johnson; Floyd A. Barbour; L. John Fahy

    1997-04-01

    Because of confidentiality requirements of this task, this topical report is necessarily brief and is based on quarterly reports that have been previously approved for release by Amoco Production Company (Amoco). More detailed topical reports have been written and will continue to be written as the project proceeds. The US Department of Energy (DOE) has approved that these detailed reports can be held in confidence for a period not to exceed three years from their dates of publication. When this three-year period has transpired, or earlier with Amoco's approval, the more detailed topical reports will be provided to DOE for its discretionary use. Three detailed technical reports have been written that cover the two-well pilot test, the laboratory work, and modeling using a coal reservoir description and Amoco's coalbed methane simulator. The document covering the two-well pilot test elicited many comments from Amoco personnel and a major revision of the document is in progress. The other two documents are essentially complete. History matching of the Allison Unit CO{sub 2} injection project has been completed and long-term performance predictions have been made using the resulting reservoir description. Idealized predictions for a quarter of a five-spot pattern of the process have been made and economics of the process evaluated.

  12. Coalbed Methane Extraction and Soil Suitability Concerns in the Powder River Basin, Montana and Wyoming

    USGS Publications Warehouse

    ,

    2006-01-01

    The Powder River Basin is located in northeastern Wyoming and southeastern Montana. It is an area of approximately 55,000 square kilometers. Extraction of methane gas from the coal seams that underlie the Powder River Basin began in Wyoming in the late 1980s and in Montana in the late 1990s. About 100-200 barrels of co-produced water per day are being extracted from each active well in the Powder River Basin, which comes to over 1.5 million barrels of water per day for all the active coalbed methane wells in the Basin. Lab testing indicates that Powder River Basin co-produced water is potable but is high in sodium and other salts, especially in the western and northern parts of the Powder River Basin. Common water management strategies include discharge of co-produced water into drainages, stock ponds, evaporation ponds, or infiltration ponds; treatment to remove sodium; or application of the water directly on the land surface via irrigation equipment or atomizers. Problems may arise because much of the Powder River Basin contains soils with high amounts of swelling clays. As part of the USGS Rocky Mountain Geographic Science Center's hyperspectral research program, researchers are investigating whether hyperspectral remote sensing data can be beneficial in locating areas of swelling clays. Using detailed hyperspectral data collected over parts of the Powder River Basin and applying our knowledge of how the clays of interest reflect energy, we will attempt to identify and map areas of swelling clays. If successful, such information will be useful to resource and land managers.

  13. Powder River Basin Coalbed Methane Development and Produced Water Management Study

    SciTech Connect

    Advanced Resources International

    2002-11-30

    Coalbed methane resources throughout the entire Powder River Basin were reviewed in this analysis. The study was conducted at the township level, and as with all assessments conducted at such a broad level, readers must recognize and understand the limitations and appropriate use of the results. Raw and derived data provided in this report will not generally apply to any specific location. The coal geology in the basin is complex, which makes correlation with individual seams difficult at times. Although more than 12,000 wells have been drilled to date, large areas of the Powder River Basin remain relatively undeveloped. The lack of data obviously introduces uncertainty and increases variability. Proxies and analogs were used in the analysis out of necessity, though these were always based on sound reasoning. Future development in the basin will make new data and interpretations available, which will lead to a more complete description of the coals and their fluid flow properties, and refined estimates of natural gas and water production rates and cumulative recoveries. Throughout the course of the study, critical data assumptions and relationships regarding gas content, methane adsorption isotherms, and reservoir pressure were the topics of much discussion with reviewers. A summary of these discussion topics is provided as an appendix. Water influx was not modeled although it is acknowledged that this phenomenon may occur in some settings. As with any resource assessment, technical and economic results are the product of the assumptions and methodology used. In this study, key assumptions as well as cost and price data, and economic parameters are presented to fully inform readers. Note that many quantities shown in various tables have been subject to rounding; therefore, aggregation of basic and intermediate quantities may differ from the values shown.

  14. Mosquito larval habitat mapping using remote sensing and GIS: Implications of coalbed methane development and West Nile virus

    SciTech Connect

    Zou, L.; Miller, S.N.; Schmidtmann, E.T.

    2006-09-15

    Potential larval habitats of the mosquito Culex tarsalis (Coquillett), implicated as a primary vector of West Nile virus in Wyoming, were identified using integrated remote sensing and geographic information system (GIS) analyses. The study area is in the Powder River Basin of north central Wyoming, an area that has been undergoing a significant increase in coalbed methane gas extractions since the late 1990s. Large volumes of water are discharged, impounded, and released during the extraction of methane gas, creating aquatic habitats that have the potential to support immature mosquito development. Landsat TM and ETM + data were initially classified into spectrally distinct water and vegetation classes, which were in turn used to identify suitable larval habitat sites. This initial habitat classification was refined using knowledge-based GIS techniques requiring spatial data layers for topography, streams, and soils to reduce the potential for overestimation of habitat. Accuracy assessment was carried out using field data and high-resolution aerial photography commensurate with one of the Landsat images. The classifier can identify likely habitat for ponds larger than 0.8 ha (2 acres) with generally satisfactory results (72.1%) with a lower detection limit of approximate to 0.4 ha (1 acre). Results show a 75% increase in potential larval habitats from 1999 to 2004 in the study area, primarily because of the large increase in small coalbed methane water discharge ponds. These results may facilitate mosquito abatement programs in the Powder River Basin with the potential for application throughout the state and region.

  15. Hydrodynamics of coalbed methane reservoirs in the Black Warrior Basin: Key to understanding reservoir performance and environmental issues

    USGS Publications Warehouse

    Pashin, J.C.

    2007-01-01

    The Black Warrior Basin of the southeastern United States hosts one of the world's most prolific and long-lived coalbed methane plays, and the wealth of experience in this basin provides insight into the relationships among basin hydrology, production performance, and environmental issues. Along the southeast margin of the basin, meteoric recharge of reservoir coal beds exposed in an upturned fold limb exerts a strong control on water chemistry, reservoir pressure, and production performance. Fresh-water plumes containing Na-HCO3 waters with low TDS content extend from the structurally upturned basin margin into the interior of the basin. Northwest of the plumes, coal beds contain Na-Cl waters with moderate to high-TDS content. Carbon isotope data from produced gas and mineral cements suggest that the fresh-water plumes have been the site of significant bacterial activity and that the coalbed methane reservoirs contain a mixture of thermogenic and late-stage biogenic gases. Water produced from the fresh-water plumes may be disposed safely at the surface, whereas underground injection has been used locally to dispose of highly saline water. Wells in areas that had normal hydrostatic reservoir pressure prior to development tend to produce large volumes of water and may take up to 4 a to reach peak gas production. In contrast, wells drilled in naturally underpressured areas distal to the fresh-water plumes typically produce little water and achieve peak gas rates during the first year of production. Environmental debate has focused largely on issues associated with hydrologic communication between deep reservoir coal beds and shallow aquifers. In the coalbed methane fields of the Black Warrior Basin, a broad range of geologic evidence suggests that flow is effectively confined within coal and that the thick intervals of marine shale separating coal zones limit cross-formational flow. ?? 2007 Elsevier Ltd. All rights reserved.

  16. Production waters associated with the Ferron coalbed methane fields, central Utah: Chemical and isotopic composition and volumes

    USGS Publications Warehouse

    Rice, C.A.

    2003-01-01

    This study investigated the composition of water co-produced with coalbed methane (CBM) from the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in east-central Utah to better understand coalbed methane reservoirs. The Ferron coalbed methane play currently has more than 600 wells producing an average of 240 bbl/day/well water. Water samples collected from 28 wellheads in three fields (Buzzards Bench, Drunkards Wash, and Helper State) of the northeast-southwest trending play were analyzed for chemical and stable isotopic composition.Water produced from coalbed methane wells is a Na-Cl-HCO3 type. Water from the Drunkards Wash field has the lowest total dissolved solids (TDS) (6300 mg/l) increasing in value to the southeast and northeast. In the Helper State field, about 6 miles northeast, water has the highest total dissolved solids (43,000 mg/l), and major ion abundance indicates the possible influence of evaporite dissolution or mixing with a saline brine. In the southern Buzzards Bench field, water has variable total dissolved solids that are not correlated with depth or spatial distance. Significant differences in the relative compositions are present between the three fields implying varying origins of solutes and/or different water-rock interactions along multiple flow paths.Stable isotopic values of water from the Ferron range from +0.9??? to -11.4??? ?? 18O and -32??? to -90??? ?? 2H and plot below the global meteoric water line (GMWL) on a line near, but above values of present-day meteoric water. Isotopic values of Ferron water are consistent with modification of meteoric water along a flow path by mixing with an evolved seawater brine and/or interaction with carbonate minerals. Analysis of isotopic values versus chloride (conservative element) and total dissolved solids concentrations indicates that recharge water in the Buzzards Bench area is distinct from recharge water in Drunkards Wash and is about 3 ??C warmer. These variations in

  17. Feasibility of CO2 Sequestration with Simultaneous Enhanced Coalbed Methane Recovery in the Powder River Basin, Wyoming

    NASA Astrophysics Data System (ADS)

    Ross, H. E.; Zoback, M. D.

    2005-12-01

    CO2 sequestration in geological formations has been proposed as a means to reduce greenhouse gas concentrations in the atmosphere. Coal is an attractive geologic environment for CO2 sequestration because CO2 is retained in the coal as an adsorbed phase and the cost of sequestration can be offset by enhanced coalbed methane recovery. Using reservoir simulations of sub-bituminous coal in the Powder River Basin, Wyoming, we examined the feasibility of injecting and sequestering CO2 in this basin, particularly looking at whether hydraulically fracturing the coal would help increase CO2 injectivity. Our 3D model was built in an area where the least principal stress is equal to the overburden stress, resulting in horizontal hydraulic fractures, and gamma ray logs from coalbed methane wells were used to determine the depth and thickness of the coal. These wells produce from the Big George coal, which is approximately 20 m thick in this area, with a depth to the top of 310-360 m. Geostatistical techniques were employed to populate the coal matrix and cleats with permeability and porosity data taken from published reports. We conducted enhanced coalbed methane simulations using a commercial enhanced coalbed methane simulator. Our base case involved one injection well and one production well (1/4 of a 5-spot pattern). We then added a hydraulic fracture at the base of the injector and closed the rest of the well off. All our simulations were run with and without coal matrix shrinkage and swelling. The natural fracture system of the coal is the main pathway for gas migration. We found that gravity and buoyancy were the major driving forces behind gas flow within the coal, which reduced gas sweep efficiency and sequestration. Gravity caused the gas to migrate upwards at first and then along the top of the coal. The presence of the hydraulic fracture assisted in greater penetration of gas into the base of the reservoir, creating a more uniform vertical sweep as gas rose to the

  18. Developmental geology of coalbed methane from shallow to deep in Rocky Mountain basins and in Cook Inlet-Matanuska Basin, Alaska, USA and Canada

    USGS Publications Warehouse

    Johnson, R.C.; Flores, R.M.

    1998-01-01

    The Rocky Mountain basins of western North America contain vast deposits of coal of Cretaceous through early Tertiary age. Coalbed methane is produced in Rocky Mountain basins at depths ranging from 45 m (150 ft) to 1981 m (6500 ft) from coal of lignite to low-volatile bituminous rank. Although some production has been established in almost all Rocky Mountain basins, commercial production occurs in only a few. despite more than two decades of exploration for coalbed methane in the Rocky Mountain region, it is still difficult to predict production characteristics of coalbed methane wells prior to drilling. Commonly cited problems include low permeabilities, high water production, and coals that are significantly undersaturated with respect to methane. Sources of coalbed gases can be early biogenic, formed during the early stages of coalification, thermogenic, formed during the main stages of coalification, or late stage biogenic, formed as a result of the reintroduction of methane-gnerating bacteria by groundwater after uplift and erosion. Examples of all three types of coalbed gases, and combinations of more than one type, can be found in the Rocky Mountain region. Coals in the Rocky Mountain region achieved their present ranks largely as a result of burial beneath sediments that accumulated during the Laramide orogeny (Late Cretaceous through the end of the eocene) or shortly after. Thermal events since the end of the orogeny have also locally elevated coal ranks. Coal beds in the upper part of high-volatile A bituminous rank or greater commonly occur within much more extensive basin-centered gas deposits which cover large areas of the deeper parts of most Rocky Mountain basins. Within these basin-centered deposits all lithologies, including coals, sandstones, and shales, are gas saturated, and very little water is produced. The interbedded coals and carbonaceous shales are probably the source of much of this gas. Basin-centered gas deposits become overpressured

  19. Coal-bed methane production in eastern Kansas: Its potential and restraints

    SciTech Connect

    Stoeckinger, B.T.

    1989-08-01

    In 1921 and again in 1988, workers demonstrated that the high volatile A and B coals of the Pennsylvanian Cherokee Group can be produced economically from vertically drilled holes, and that some of these coals have a gas content as high as 200 ft{sup 3}/ton. Detailed subsurface mapping on a county-by-county basis using geophysical logs shows the Weir coal seam to be the thickest (up to 6 ft thick) and to exist in numerous amoeba-shaped pockets covering several thousand acres. Lateral pinch-out into deltaic sands offers a conventional gas source. New attention to geophysical logging shows most coals have a negative SP response, high resistivities, and densities of 1.6 g/cm{sup 3}. Highly permeable coals cause lost circulation during drilling and thief zones during cementing, and they are the source of abundant unwanted salt water. Low-permeability coals can be recognized by their high fracture gradients, which are difficult to explain but are documented to exceed 2.2. Current successful completions use both limited-entry, small-volume nitrogen stimulations or an open hole below production casing. Subsurface coals are at normal Mid-Continent pressures and may be free of water. Initially, some wells flow naturally without pumping. Saltwater disposal is often helped by the need for water in nearby waterflood projects and the easy availability of state-approved saltwater disposal wells in Mississippi and Arbuckle carbonates. Recent attempts to recomplete coal zones in slim-hole completions are having mixed results. The major restraints to coal-bed methane production are restricted to low permeability of the coals and engineering problems, not to the availability or gas content of the coals.

  20. Water quality changes as a result of coalbed methane development in a Rocky mountain watershed

    SciTech Connect

    Wang, X.; Melesse, A.M.; McClain, M.E.; Yang, W.

    2007-12-15

    Coalbed methane (CBM) development raises serious environmental concerns. In response, concerted efforts have been made to collect chemistry, salinity, and sodicity data on CBM produced water. However, little information on changes of stream water quality resulting from directly and/or indirectly received CBM produced water is available in the literature. The objective of this study was to examine changes in stream water quality, particularly sodicity and salinity, due to CBM development in the Powder River watershed, which is located in the Rocky Mountain Region and traverses the states of Wyoming and Montana. To this end, a retrospective analysis of water quality trends and patterns was conducted using data collected from as early as 1946 up to and including 2002 at four U.S. Geological Survey gauging stations along the Powder River. Trend analysis was conducted using linear regression and Seasonal Kendall tests, whereas, Tukey's test for multiple comparisons was used to detect changes in the spatial pattern. The results indicated that the CBM development adversely affected the water quality in the Powder River. First, the development elevated the stream sodicity, as indicated by a significant increase trend of the sodium adsorption ratio. Second, the development tended to shrink the water quality differences among the three downstream stations but to widen the differences between these stations and the farthest upstream station. In contrast, the development had only a minor influence on stream salinity. Hence, the CBM development is likely an important factor that can be managed to lower the stream sodicity. The management may need to take into account that the effects of the CBMdevelopment were different from one location to another along the Powder River.

  1. Coalbed methane-produced water quality and its management options in Raniganj Basin, West Bengal, India

    NASA Astrophysics Data System (ADS)

    Mendhe, Vinod Atmaram; Mishra, Subhashree; Varma, Atul Kumar; Singh, Awanindra Pratap

    2015-09-01

    Coalbed methane (CBM) recovery is associated with production of large quantity of groundwater. The coal seams are depressurized by pumping of water for regular and consistent gas production. Usually, CBM operators need to pump >10 m3 of water per day from one well, which depends on the aquifer characteristics, drainage and recharge pattern. In India, 32 CBM blocks have been awarded for exploration and production, out of which six blocks are commercially producing methane gas at 0.5 million metric standard cubic feet per day. Large amount of water is being produced from CBM producing blocks, but no specific information or data are available for geochemical properties of CBM-produced water and its suitable disposal or utilization options for better management. CBM operators are in infancy and searching for the suitable solutions for optimal management of produced water. CBM- and mine-produced water needs to be handled considering its physical and geochemical assessment, because it may have environmental as well as long-term impact on aquifer. Investigations were carried out to evaluate geochemical and hydrogeological conditions of CBM blocks in Raniganj Basin. Totally, 15 water samples from CBM well head and nine water samples from mine disposal head were collected from Raniganj Basin. The chemical signature of produced water reveals high sodium and bicarbonate concentrations with low calcium and magnesium, and very low sulphate in CBM water. It is comprehend that CBM water is mainly of Na-HCO3 type and coal mine water is of Ca-Mg-SO4 and HCO3-Cl-SO4 type. The comparative studies are also carried out for CBM- and mine-produced water considering the geochemical properties, aquifer type, depth of occurrence and lithological formations. Suitable options like impounding, reverse osmosis, irrigation and industrial use after prerequisite treatments are suggested. However, use of this huge volume of CBM- and mine-produced water for irrigation or other beneficial purposes

  2. Geologic evaluation of critical production parameters for coalbed methane resources. Part 2. Black Warrior basin. Annual report, August 1988-July 1989

    SciTech Connect

    Pashin, J.C.; Ward, W.E.; Winston, R.B.; Chandler, R.V.; Bolin, D.E.

    1990-02-01

    Geologic evaluation of critical production parameters for coalbed-methane resources in the Black Warrior basin of Alabama employed an interdisciplinary approach that utilized structural, coal-quality, sedimentologic, hydrologic, and engineering data. Results indicate that geologic factors are a major control on the producibility of coalbed methane and that completion techniques may be used to increase recovery if tailored to specific geologic settings. Sedimentologic and coal-quality parameters may be used to locate regions for coalbed-methane development by characterizing the occurrence, rank, and grade of coal resources. However, high-productivity trends within those regions are localized, and geologic data suggest that productivity trends may be predictable. Several highly productive trends occur along northeast-oriented lineaments. These lineaments are the inferred surface expression of zones of enhanced permeability which are related to fractures. Productive trends also are associated with areas of low reservoir pressure, and salinity maps indicate that fresh water has migrated toward areas with low reservoir pressure. The available data indicate that structure and hydrology are critical production parameters that may be used to identify favorable well sites within regions containing significant coalbed-methane resources.

  3. Organic Compounds in Produced Waters From Coalbed Methane Wells in the Powder River Basin, WY

    NASA Astrophysics Data System (ADS)

    Orem, W.; Lerch, H.; Rice, C.; Tatu, C.

    2003-12-01

    Coalbed methane (CBM) is a significant energy resource, accounting for about 7.5% of natural gas production in the USA. The Powder River Basin (PRB), WY is currently one of the most active CBM drilling sites in the USA. One aspect of concern in the exploitation of CBM resources is the large volumes of water recovered from wells along with the natural gas (so-called produced waters). CBM produced waters may contain coal-derived dissolved substances (inorganic and organic) of environmental concern, and a potential disposal problem for CBM producers. Studies of CBM produced water have mostly focused on inorganics. Dissolved organic compounds in CBM produced water may also present an environmental issue, but little information is available. As part of a larger study of the health and environmental effects of organic compounds derived from coal, we analyzed a number of produced water samples from CBM wells in the PRB, WY for dissolved organic substances. Our goals were results on coal-derived organic compounds in the environment to evaluate potential health and environmental impacts. In 2001, we sampled produced water from 13 CBM wells covering a broad area of the PRB in order to identify and quantify the organic compounds present. In 2002, produced water from 4 of the 2001 CBM wells and 8 new CBM wells were sampled for dissolved organic components. Produced water was collected directly from each well and filtered on site. Organic compounds were isolated from produced water samples by liquid/liquid extraction with methylene chloride and identified and quantified by gas chromatography/mass spectrometry (GC/MS). Organic compounds identified by GC/MS in extracts of the produced water samples, included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons, phthalates, aliphatic hydrocarbons, and fatty acids. However, most compounds had structures unidentified by GC/MS databases. Many of the identified organic compounds

  4. Adsorption Hysteresis and its Effect on CO2 Sequestration and Enhanced Coalbed Methane Recovery

    NASA Astrophysics Data System (ADS)

    Seto, C. J.; Tang, G. T.; Jessen, K.; Kovscek, A. R.; Orr, F. M.

    2006-12-01

    CO2 sequestration in coal reservoirs is a promising technology for reducing atmospheric CO2 concentrations. Of the candidates for geological sequestration, the physics of transport and sequestration in coal is the least well understood. Adsorption hysteresis has been observed for pure gas adsorption on some coals. It is manifest as desorption curves where the loading of gas on coal surfaces is greater than sorption at the same pressure. Current simulation technology does not have the functionality to incorporate this phenomenon that has a potentially great effect on sequestration in coalbeds. Understanding the interplay between adsorption and desorption of gas species, phase behaviour and convection is paramount to designing safe and effective sequestration projects. Our work integrates experiments and theory development. Isotherms of CH4, N2 and CO2 were measured on a sample of coal from the Powder River Basin, WY, for adsorption and desorption paths. Hysteresis was observed for all gases. Likewise, the displacment of methane by various mixtures of N2 and CO2 was also measured. Simultaneously, a model was developed to solve for the dispersion-free limit of convective transport in multiphase systems with adsorption, including the effects of volume change as components transfer from vapour to liquid and solid phases. Analytical solutions were obtained using the method of characteristics. These solutions were compared against corresponding solutions without adsorption hysteresis. For pure gas injection, in which the amount of adsorbed injected gas increases monotonically and the amount of adsorbed initial gas decreases monotonically, hysteresis effects were not observed. For injection gas mixtures of N2-CO2 displacing CH4, CO2 and N2 separated chromatographically and hysteresis effected breakthrough and bank arrival times as well as shifted overall component concentrations as the displacement progressed. When injection gas mixtures were rich in N2, the structures

  5. Dewatering systems and techniques for coalbed methane wells. Volume 2. Final report

    SciTech Connect

    Not Available

    1983-08-01

    The study shows that contemporary oil field systems are adequate for coalbed dewatering. In general, sucker rod systems were preferred for the shallower depths with fluid-operated systems more applicable for the deeper wells. No system was an overwhelming choice based on cost. Oil field electric submersibles were generally oversized for the flow rates and reservoirs used in this study.

  6. A preliminary evaluation of vertical separation between production intervals of coalbed-methane wells and water-supply wells in the Raton basin, Huerfano and Las Animas Counties, Colorado, 1999-2004

    USGS Publications Warehouse

    Watts, Kenneth R.

    2006-01-01

    The Raton Basin in southern Colorado and northern New Mexico is undergoing increased development of its coalbed-methane resources. Annual production of methane from coalbeds in the Raton Basin in Huerfano and Las Animas Counties, Colorado, increased from about 28,000,000 thousand cubic feet from 478 wells to about 80,000,000 thousand cubic feet from 1,543 wells, during 1999-2004. Annual ground-water withdrawals for coalbed-methane production increased from about 1.45 billion gallons from 480 wells to about 3.64 billion gallons from 1,568 wells, during 1999-2004. Where the coalbeds are deeply buried near the center of the Raton Basin, water pressure may be reduced as much as 250 to 300 pounds per square inch to produce the methane from the coalbeds, which is equivalent to a 577- to 692-foot lowering of water level. In 2001, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, began an evaluation of the potential effects of coalbed- methane production on the availability and sustainability of ground-water resources. In 2003, there were an estimated 1,370 water-supply wells in the Raton Basin in Colorado, and about 90 percent of these water-supply wells were less than 450 feet deep. The tops of the production (perforated) interval of 90 percent of the coalbed-methane wells in the Raton Basin (for which data were available) are deeper than about 675 feet. The potential for interference of coalbed-methane wells with nearby water-supply wells likely is limited because in most areas their respective production intervals are separated by more than a hundred to a few thousand feet of rock. The estimated vertical separation between production intervals of coalbed-methane and water-supply wells is less than 100 feet in an area about 1 to 6 miles west and southwest of Trinidad Lake and a few other isolated areas. It is assumed that in areas with less than 100 feet of vertical separation, production by coalbed-methane wells has a greater

  7. Emissions of coalbed and natural gas methane from abandoned oil and gas wells in the United States

    NASA Astrophysics Data System (ADS)

    Townsend-Small, Amy; Ferrara, Thomas W.; Lyon, David R.; Fries, Anastasia E.; Lamb, Brian K.

    2016-03-01

    Recent work indicates that oil and gas methane (CH4) inventories for the United States are underestimated. Here we present results from direct measurements of CH4 emissions from 138 abandoned oil and gas wells, a source currently missing from inventories. Most abandoned wells do not emit CH4, but 6.5% of wells had measurable CH4 emissions. Twenty-five percent of wells we visited that had not been plugged emitted > 5 g CH4 h-1. Stable isotopes indicate that wells emit natural gas and/or coalbed CH4. We estimate that abandoned wells make a small contribution (<1%) to regional CH4 emissions in our study areas. Additional data are needed to accurately determine the contribution of abandoned wells to national CH4 budgets, particularly measurements in other basins and better characterization of the abundance and regional distribution of high emitters.

  8. Mechanical and thermal control of cleating and shearing in coal: examples from the Alabama coalbed methane field, USA

    USGS Publications Warehouse

    Pashin, Jack; Carroll, R.E.; Hatch, Joseph R.; Goldhaber, Martin B.

    1999-01-01

    Natural fractures provide most of the interconnected macroporosity in coal. Therefore, understanding the characteristics of these fractures and the associated mechanisms of formation is essential for effective coalbed methane exploration and field management. Natural fractures in coal can be divided into two general types: cleat and shear structures. Cleat has been studied for more than a century, yet the mechanisms of cleat formation remain poorly understood (see reviews by Close, 1993; Laubach et al.,1998). An important aspect of cleating is that systematic fracturing of coal is takes place in concert with devolatization and concomitant shrinkage of the coal matrix during thermal maturation (Ammosov and Eremin, 1960). Coal, furthermore, is a mechanically weak rock type that is subject to bedding-plane shear between more competent beds like shale, sandstone, and limestone. Yet, the significance of shear structures in coal has only begun to attract scientific interest (Hathaway and Gayer, 1996; Pashin, 1998).

  9. Effects of resident water and non-equilibrium adsorption on the primary and enhanced coalbed methane gas recovery

    NASA Astrophysics Data System (ADS)

    Jahediesfanjani, Hossein

    The major part of the gas in coalbed methane and shale gas reservoirs is stored as the adsorbed gas in the coal and organic materials of the black shale internal surfaces. The sorption sites in both reservoirs are composed of several macropores that contain very small pore sizes. Therefore, the adsorption/desorption is very slow process and follows a non-equilibrium trend. The time-dependency of the sorption process is further affected by the reservoir resident water. Water can diffuse into the matrix and adsorption sites, plug the pores and affect the reservoir gas production. This study presents an experimental and theoretical procedure to investigate the effects of the resident water and time-dependency of the sorption process on coalbed and shale gas primary and enhanced recovery by simultaneous CO 2/N2 injection. Series of the experiments are conducted to construct both equilibrium and non-equilibrium single and multi-component isotherms with the presence of water. A novel and rapid data interpretation technique is developed based on the nonequilibrium adsorption/desorption thermodynamics, mass conservation law, and volume filling adsorption theory. The developed technique is implemented to construct both equilibrium and non-equilibrium multi-component multi-phase isotherms from the early time experimental measurements. The non-equilibrium isotherms are incorporated in the coalbed methane/shale gas reservoir simulations to account for the time-dependency of the sorption process. The experimental results indicate that the presence of water in the sorption system reduces both carbon dioxide and nitrogen adsorption rates. Reduction in the adsorption rate for carbon dioxide is more than nitrogen. The results also indicate that the resident water reduces the adsorption ability of low rank coals more than high rank ones. The results of the multi-component sorption tests indicate that increasing the initial mole fraction of the nitrogen gas in the injected CO2/N2

  10. Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead

    SciTech Connect

    BC Technologies

    2009-12-30

    Water associated with coalbed methane (CBM) production is a significant and costly process waste stream, and economic treatment and/or disposal of this water is often the key to successful and profitable CBM development. In the past decade, advances have been made in the treatment of CBM produced water. However, produced water generally must be transported in some fashion to a centralized treatment and/or disposal facility. The cost of transporting this water, whether through the development of a water distribution system or by truck, is often greater than the cost of treatment or disposal. To address this economic issue, BC Technologies (BCT), in collaboration with Oak Ridge National Laboratory (ORNL) and International Petroleum Environmental Consortium (IPEC), proposed developing a mechanical unit that could be used to treat CBM produced water by forming gas hydrates at the wellhead. This process involves creating a gas hydrate, washing it and then disassociating hydrate into water and gas molecules. The application of this technology results in three process streams: purified water, brine, and gas. The purified water can be discharged or reused for a variety of beneficial purposes and the smaller brine can be disposed of using conventional strategies. The overall objectives of this research are to develop a new treatment method for produced water where it could be purified directly at the wellhead, to determine the effectiveness of hydrate formation for the treatment of produced water with proof of concept laboratory experiments, to design a prototype-scale injector and test it in the laboratory under realistic wellhead conditions, and to demonstrate the technology under field conditions. By treating the water on-site, producers could substantially reduce their surface handling costs and economically remove impurities to a quality that would support beneficial use. Batch bench-scale experiments of the hydrate formation process and research conducted at ORNL

  11. U.S. Geological Survey and Bureau of Land Management Cooperative Coalbed Methane Project in the Powder River Basin, Wyoming

    USGS Publications Warehouse

    ,

    2006-01-01

    Introduction: Evidence that earthquakes threaten the Mississippi, Ohio, and Wabash River valleys of the Central United States abounds. In fact, several of the largest historical earthquakes to strike the continental United States occurred in the winter of 1811-1812 along the New Madrid seismic zone, which stretches from just west of Memphis, Tenn., into southern Illinois (fig. 1). Several times in the past century, moderate earthquakes have been widely felt in the Wabash Valley seismic zone along the southern border of Illinois and Indiana (fig. 1). Throughout the region, between 150 and 200 earthquakes are recorded annually by a network of monitoring instruments, although most are too small to be felt by people. Geologic evidence for prehistoric earthquakes throughout the region has been mounting since the late 1970s. But how significant is the threat? How likely are large earthquakes and, more importantly, what is the chance that the shaking they cause will be damaging?The Bureau of Land Management (BLM) Wyoming Reservoir Management Group and the U.S. Geological Survey (USGS) began a cooperative project in 1999 to collect technical and analytical data on coalbed methane (CBM) resources and quality of the water produced from coalbeds in the Wyoming part of the Powder River Basin. The agencies have complementary but divergent goals and these kinds of data are essential to accomplish their respective resource evaluation and management tasks. The project also addresses the general public need for information pertaining to Powder River Basin CBM resources and development. BLM needs, which relate primarily to the management of CBM resources, include improved gas content and gas in-place estimates for reservoir characterization and resource/reserve assessment, evaluation, and utilization. USGS goals include a basinwide assessment of CBM resources, an improved understanding of the nature and origin of coalbed gases and formation waters, and the development of predictive

  12. Geologic and hydrologic characterization of coalbed-methane reservoirs in the San Juan basin

    SciTech Connect

    Kaiser, W.R. ); Ayers, W.B. Jr.

    1994-09-01

    Fruitland coals are best developed in the north-central part of the San Juan basin. Coal distribution is controlled by shoreline and fluvial depositional settings. Hydraulic gradient, pressure regime, and hydrochemistry reflect regional permeability contrasts. The most productive (>1 MMcf/D) coalbed wells occur along a structural hinge line in association with a regional permeability barrier (no-flow boundary) at the basin center.

  13. Effects of coal-bed methane discharge waters on the vegetation and soil ecosystem in Powder River Basin, Wyoming

    USGS Publications Warehouse

    Stearns, M.; Tindall, J.A.; Cronin, G.; Friedel, M.J.; Bergquist, E.

    2005-01-01

    Coal-bed methane (CBM) co-produced discharge waters in the Powder River Basin of Wyoming, resulting from extraction of methane from coal seams, have become a priority for chemical, hydrological and biological research during the last few years. Soil and vegetation samples were taken from affected and reference sites (upland elevations and wetted gully) in Juniper Draw to investigate the effects of CBM discharge waters on soil physical and chemical properties and on native and introduced vegetation density and diversity. Results indicate an increase of salinity and sodicity within local soil ecosystems at sites directly exposed to CBM discharge waters. Elevated concentrations of sodium in the soil are correlated with consistent exposure to CBM waters. Clay-loam soils in the study area have a much larger specific surface area than the sandy soils and facilitate a greater sodium adsorption. However, there was no significant relation between increasing water sodium adsorption ratio (SAR) values and increasing sediment SAR values downstream; however, soils exposed to the CBM water ranged from the moderate to severe SAR hazard index. Native vegetation species density was highest at the reference (upland and gully) and CBM affected upland sites. The affected gully had the greatest percent composition of introduced vegetation species. Salt-tolerant species had the greatest richness at the affected gully, implying a potential threat of invasion and competition to established native vegetation. These findings suggest that CBM waters could affect agricultural production operations and long-term water quality. ?? Springer 2005.

  14. Re-assessing H and C Isotope Signatures of Biogenic Methane in Coalbeds and Shales: Metabolic Pathways and Alternative Influences

    NASA Astrophysics Data System (ADS)

    Vinson, D. S.; McIntosh, J. C.; Blair, N. E.; Martini, A. M.

    2013-12-01

    Hydrogen and carbon isotopes of microbial methane have long been applied to distinguish metabolic pathways of methanogenesis (utilization of acetate vs. H2+CO2 by methanogens). However, application of isotopic tools in hydrocarbon and biodegradation systems requires improved understanding of what is actually recorded by C and H isotopes of biogenic methane. Unlike culture studies where the fractionation factors of methanogenic pathways have been defined, field-collected gas or water samples represent net apparent isotope signatures influenced by a variety of overlapping water-rock-microbial interaction processes. Understanding these processes is important for modeling subsurface carbon cycling and biostimulation efforts for enhanced microbial gas production. Briefly, trends are apparent from a re-analysis of recently published water and gas isotope data from biogenic coalbed methane and shale gas systems: (1) δ13C-CH4 and the relationship between δ13C-CH4 and δ13C-CO2 (α13CCO2-CH4=(δ13C-CO2 + 1000)/(δ13C-CH4 +1000)), can also record the competition between methanogenesis and non-methanogenic processes (e.g. sulfate reduction), rather than simply recording the pathways of methanogenesis itself; and (2) Interpretation of δ2H-CH4 and δ2H-H2O can be inconsistent with δ13C-based fingerprinting techniques and indeed could be highly influenced by isotope exchange between water and methane precursors. This study provides an alternative approach for interpreting δ13C in shallow biogenic gas which considers that Corg may be consumed by competing, highly-fractionating and less-fractionating processes (e.g. methanogenesis and sulfate reduction, respectively). Whereas variation in apparent α13CCO2-CH4 could be inferred to indicate variation of metabolic pathways (that is, acetate fermentation vs. CO2 reduction) in some coalbed methane systems such as the Powder River Basin, the influx of sulfate relative to the overall Corg biodegradation rate could also be an

  15. Matrix Shrinkage and Swelling Effects on Economics of Enhanced Coalbed Methane Production and CO2 Sequestration in Coal

    SciTech Connect

    Gorucu, F.B.; Jikich, S.A.; Bromhal, G.S.; Sams, W.N.; Ertekin, T.; Smith, D.H.

    2005-09-01

    Increases in CO2 levels in the atmosphere and their contributions to global climate change have been a major concern. It has been shown that CO2 injection can enhance the methane recovery from coal. Accordingly, sequestration costs can be partially offset by the value added product. Indeed, coal seam sequestration may be profitable, particularly with the introduction of incentives for CO2 sequestration. Hence, carbon dioxide sequestration in unmineable coals is a very attractive option, not only for environmental reasons, but also for possible economic benefits. Darcy flow through cleats is an important transport mechanism in coal. Cleat compression and permeability changes due to gas sorption desorption, changes of effective stress, and matrix swelling and shrinkage introduce a high level of complexity into the feasibility of a coal sequestration project. The economic effects of carbon dioxide-induced swelling on permeabilities and injectivities has received little (if any) detailed attention. Carbon dioxide and methane have different swelling effects on coal. In this work, the Palmer-Mansoori model for coal shrinkage and permeability increases during primary methane production was re-written to also account for coal swelling caused by carbon dioxide sorption. The generalized model was added to PSU-COALCOMP, a dual porosity reservoir simulator for primary and enhanced coalbed methane production. A standard five-spot of vertical wells and representative coal properties for Appalachian coals were used.[1] Simulations and sensitivity analyses were performed with the modified simulator for nine different parameters, including coal seam and operational parameters and economic criteria. The coal properties and operating parameters that were varied included Young’s modulus, Poisson’s ratio, the cleat porosity, and the injection pressure. The economic variables included CH4 price, CO2 cost, CO2 credit, water disposal cost, and interest rate. Net present value analyses

  16. Feasibility of no-proppant stimulation to enhance removal of methane from the Mary Lee Coalbed

    SciTech Connect

    Lambert, S.W.; Trevits, M.A.

    1980-04-01

    One experimental approach to hydraulic stimulation is to use fluid to propagate fractures but not to incorporate solid proppant material in the design. The elimination of solid material negates problems related to wellbore sand proppant influx and allows better fracture height control since extremely low injection rates can be used. The Mary Lee Coalbed was stimulated using a 53,000 gallon no-proppant treatment at a 1,150 foot deep test well located approximately 1,600 feet in advance of mining. The well produced for 147 days and gas flow rates declined sharply, ceasing when intercepted by mining. Production comparison of the no-proppant test with another test incorporating sand proppant indicates that the 53,000 gallon no-proppant treatment was less effective than the more conventional 21,000 gallon treatment. The results from the no-proppant test indicate that very few roof rock fluid penetrations occurred during the course of hydraulic stimulation. It cannot be determined, however, if sparsity of roof penetration was due to the use of very low injection rates or because roof rock in the physical test area was less jointed and, therefore, less prone to stimulation fluid invasions. Because gas flow results gathered are inconclusive, the application of no-proppant stimulation designs for other than research is not recommended at this time. The lower injection rate approach to fracture height control is, however, theoretically sound and because limiting upward fracture growth in coalbeds may be desirable to future borehole gas drainage activities, no-proppant experiments could be justified on a limited scale.

  17. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    SciTech Connect

    Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

    2013-10-04

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  18. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    NASA Astrophysics Data System (ADS)

    Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

    2013-12-01

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (˜3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na-Mg-SO4 salts more soluble than gypsum. Irrigation with high SAR (˜24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  19. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    USGS Publications Warehouse

    Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

    2013-01-01

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  20. The relative contribution of methanotrophs to microbial communities and carbon cycling in soil overlying a coal-bed methane seep

    USGS Publications Warehouse

    Mills, Christopher T.; Slater, Gregory F.; Dias, Robert F.; Carr, Stephanie A.; Reddy, Christopher M.; Schmidt, Raleigh; Mandernack, Kevin W.

    2013-01-01

    Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. 14C-dead) carbon to soil microbial communities. Natural abundance 13C and 14C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison of PLFA and 16s rDNA data suggested type I and II methanotroph populations were well estimated and overestimated by their PLFA biomarkers, respectively. The δ13C values of PLFAs common in type I and II methanotrophs were as negative as −67‰ and consistent with the assimilation of CBM. PLFAs more indicative of nonmethanotrophic bacteria had δ13C values that were intermediate indicating assimilation of both plant- and CBM-derived carbon. Δ14C values of select PLFAs (−351 to −936‰) indicated similar patterns of CBM assimilation by methanotrophs and nonmethanotrophs and were used to estimate that 35–91% of carbon assimilated by nonmethanotrophs was derived from CBM depending on time of sampling and soil depth.

  1. Origin of minerals in joint and cleat systems of the Pottsville Formation, Black Warrior basin, Alabama: Implications for coalbed methane generation and production

    USGS Publications Warehouse

    Pitman, J.K.; Pashin, J.C.; Hatch, J.R.; Goldhaber, M.B.

    2003-01-01

    Coalbed methane is produced from naturally fractured strata in the lower Pennsylvanian Pottsville Formation in the eastern part of the Black Warrior basin, Alabama. Major fracture systems include orthogonal fractures, which consist of systematic joints in siliciclastic strata and face cleats in coal that strike northeast throughout the basin. Calcite and minor amounts of pyrite commonly fill joints in sandstone and shale and, less commonly, cleats in coal. Joint-fill calcite postdates most pyrite and is a weakly ferroan, coarse-crystalline variety that formed during a period of uplift and erosion late in the burial history. Pyrite forms fine to coarse euhedral crystals that line joint walls or are complexly intergrown with calcite. Stable-isotope data reveal large variations in the carbon isotope composition of joint- and cleat-fill calcite (-10.3 to + 24.3??? Peedee belemnite [PDB]) but only a relatively narrow range in the oxygen-isotope composition of this calcite (-16.2 to -4.1 ??? PDB). Negative carbon values can be attributed to 13C-depleted CO2 derived from the oxidation of organic matter, and moderately to highly positive carbon values can be attributed to bacterial methanogenesis. Assuming crystallization temperatures of 20-50??C, most joint- and cleat-fill calcite precipitated from fluids with ??18O ratios ranging from about -11 to +2 ??? standard mean ocean water (SMOW). Uplift and unroofing since the Mesozoic led to meteoric recharge of Pottsville strata and development of freshwater plumes that were fed by meteoric recharge along the structurally upturned, southeastern margin of the basin. Influxes of fresh water into the basin via faults and coalbeds facilitated late-stage bacterial methanogenesis, which accounts for the high gas content in coal and the carbonate cementation of joints and cleats. Diagenetic and epigenetic minerals can affect the transmissivity and storage capacity of joints and cleats, and they appear to contribute significantly to

  2. The effect of coal-bed methane water on spearmint and peppermint.

    PubMed

    Zheljazkov, Valtcho D; Cantrell, Charles L; Astatkie, Tess; Schlegel, Vicki; Jeliazkova, Ekaterina; Lowe, Derek

    2013-11-01

    Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce the pressure and to release the methane, the water needs to be pumped out. The resulting waste water is known as coal bed methane water (CBMW). Major concerns with the use of CBMW are its high concentrations of S, Na, dissolved Ca, Mg, SO, and bicarbonate (HCO). Irrigation water is a scarce resource in most of the western states. The objective of this study was to evaluate the effect of various amounts of CBMW on the growth, essential oil content, composition, and antioxidant activity of spearmint ( L.) and peppermint ( L.) crops that were irrigated with the water. These two crops are grown in some western states and are potential specialty crops to Wyoming farmers. The irrigation treatments were 0% CBMW (tap water only), 25% CBMW (25% CBMW plus 75% tap water), 50% CBMW (50% CBMW and 50% tap water), 75% CBMW (75% CBMW plus 25% tap water), and 100% CBMW. Analyses of the data revealed that the CBMW treatments did not affect the antioxidant capacity of spearmint or peppermint oil (242 and 377 μmol L Trolox g, respectively) or their major oil constituents (carvone or menthol). Coal bed methane water at 100% increased total phenols and total flavonoids in spearmint but not in peppermint. Coal bed methane water also affected oil content in peppermint but not in spearmint. Spearmint and peppermint could be watered with CBMW at 50% without suppression of fresh herbage yields. However, CBMW at 75 and 100% reduced fresh herbage yields of both crops and oil yields of peppermint relative to the control.

  3. Structure, sedimentology, coal quality, and hydrology of the Black Warrior Basin in Alabama: Controls on the occurrence and producibility of coalbed methane. Topical report, August 1, 1987-December 20, 1990

    SciTech Connect

    Pashin, J.C.

    1991-03-01

    Geologic evaluation of critical production parameters in the Black Warrior basin employed an interdisciplinary approach that utilized structural, sedimentologic, coal-quality, hydrologic, completion, and production data. Results indicate that geologic structure affected sedimentation, coalification, hydrogeology, and the ultimate occurrence and producibility of coalbed methane. Geologic trend analysis was used to characterize regional coalbed-methane potential, and results indicate that many parts of the basin have untapped resources. Some highly productive trends coincide with northeast-trending structures that apparently are zones of enhanced fracture permeability. Water-production data indicate that many high-permeability trends exist that are not associated with exceptional coalbed-methane production and that the coal beds are structurally compartmentalized reservoirs. Water-level data indicate that all highly productive coalbed-methane wells occur where reservoir pressure has been lowered significantly. Therefore, highly productive areas apparently represent structural compartments where formation pressure has been lowered enough to facilitate desorption of a large quantity of methane. Results of the research suggest that completion technology and field design can be tailored to specific geologic settings to produce from reservoir compartments that are readily depressurized, thereby optimizing reservoir drainage.

  4. Depositional sequence stratigraphy and architecture of the cretaceous ferron sandstone: Implications for coal and coalbed methane resources - A field excursion

    USGS Publications Warehouse

    Garrison, J.R.; Van Den, Bergh; Barker, C.E.; Tabet, D.E.

    1997-01-01

    This Field Excursion will visit outcrops of the fluvial-deltaic Upper Cretaceous (Turonian) Ferron Sandstone Member of the Mancos Shale, known as the Last Chance delta or Upper Ferron Sandstone. This field guide and the field stops will outline the architecture and depositional sequence stratigraphy of the Upper Ferron Sandstone clastic wedge and explore the stratigraphic positions and compositions of major coal zones. The implications of the architecture and stratigraphy of the Ferron fluvial-deltaic complex for coal and coalbed methane resources will be discussed. Early works suggested that the southwesterly derived deltaic deposits of the the upper Ferron Sandstone clastic wedge were a Type-2 third-order depositional sequence, informally called the Ferron Sequence. These works suggested that the Ferron Sequence is separated by a type-2 sequence boundary from the underlying 3rd-order Hyatti Sequence, which has its sediment source from the northwest. Within the 3rd-order depositional sequence, the deltaic events of the Ferron clastic wedge, recognized as parasequence sets, appear to be stacked into progradational, aggradational, and retrogradational patterns reflecting a generally decreasing sediment supply during an overall slow sea-level rise. The architecture of both near-marine facies and non-marine fluvial facies exhibit well defined trends in response to this decrease in available sediment. Recent studies have concluded that, unless coincident with a depositional sequence boundary, regionally extensive coal zones occur at the tops of the parasequence sets within the Ferron clastic wedge. These coal zones consist of coal seams and their laterally equivalent fissile carbonaceous shales, mudstones, and siltstones, paleosols, and flood plain mudstones. Although the compositions of coal zones vary along depositional dip, the presence of these laterally extensive stratigraphic horizons, above parasequence sets, provides a means of correlating and defining the tops

  5. Expansion and Enhacement of the Wyoming Coalbed Methane Clearinghouse Website to the Wyoming Energy Resources Information Clearinghouse.

    SciTech Connect

    Hulme, Diana; Hamerlinck, Jeffrey; Bergman, Harold; Oakleaf, Jim

    2010-03-25

    Energy development is expanding across the United States, particularly in western states like Wyoming. Federal and state land management agencies, local governments, industry and non-governmental organizations have realized the need to access spatially-referenced data and other non-spatial information to determine the geographical extent and cumulative impacts of expanding energy development. The Wyoming Energy Resources Information Clearinghouse (WERIC) is a web-based portal which centralizes access to news, data, maps, reports and other information related to the development, management and conservation of Wyoming's diverse energy resources. WERIC was established in 2006 by the University of Wyoming's Ruckelshaus Institute of Environment and Natural Resources (ENR) and the Wyoming Geographic Information Science Center (WyGISC) with funding from the US Department of Energy (DOE) and the US Bureau of Land Management (BLM). The WERIC web portal originated in concept from a more specifically focused website, the Coalbed Methane (CBM) Clearinghouse. The CBM Clearinghouse effort focused only on coalbed methane production within the Powder River Basin of northeast Wyoming. The CBM Clearinghouse demonstrated a need to expand the effort statewide with a comprehensive energy focus, including fossil fuels and renewable and alternative energy resources produced and/or developed in Wyoming. WERIC serves spatial data to the greater Wyoming geospatial community through the Wyoming GeoLibrary, the WyGISC Data Server and the Wyoming Energy Map. These applications are critical components that support the Wyoming Energy Resources Information Clearinghouse (WERIC). The Wyoming GeoLibrary is a tool for searching and browsing a central repository for metadata. It provides the ability to publish and maintain metadata and geospatial data in a distributed environment. The WyGISC Data Server is an internet mapping application that provides traditional GIS mapping and analysis

  6. A multicomponent, two-phase-flow model for CO{sub 2} storage and enhanced coalbed-methane recovery

    SciTech Connect

    Seto, C.J.; Jessen, K.; Orr, F.M.

    2009-03-15

    Injection of CO{sub 2} into deep unminable coal seams is an option for geological storage of CO{sub 2} and may enhance the recovery of CH{sub 4} in these systems, making coal reservoirs interesting candidates for sequestration. New analytical solutions are presented for two-phase, three- and four-component flow with volume change on mixing in adsorbing systems. We analyze the simultaneous flow of water and gas containing multiple adsorbing components. The displacement problem is solved by the method of characteristics. Mixtures of N{sub 2}, CH{sub 4}, CO{sub 2}, and H{sub 2}O are used to represent enhanced coalbed-methane (ECBM) recovery processes. The displacement behavior is demonstrated to be strongly dependent on the relative adsorption strength of the gas components. In ternary systems, two types of solutions result. When a gas rich in CO{sub 2} displaces a less strongly adsorbing gas (such as CH{sub 4}), a shock solution is obtained. As the injected gas propagates through the system, CO{sub 2} is removed from the mobile phase by adsorption, while desorbed gas propagates ahead of the CO{sub 2} front. The adsorption of CO{sub 2} reduces the flow velocity of the injected gas, delaying breakthrough and allowing for more CO{sub 2} to be sequestered per volume of CH{sub 4} produced. For injection gases rich in N{sub 2}, a decrease in partial pressure is required to displace the preferentially adsorbed CH{sub 4} and a rarefaction solution results. In quaternary displacements with injection-gas mixtures of CO{sub 2} and N{sub 2}, the relative adsorption strength of the components results in solutions that exhibit features of both the N{sub 2}-rich and CO{sub 2}-rich ternary displacements. Analytical solutions for ECBM recovery processes provide insight into the complex interplay of adsorption, phase behavior, and convection.

  7. Carbon Dioxide Transport and Sorption Behavior in Confined Coal Cores for Enhanced Coalbed Methane and CO2 Sequestration

    SciTech Connect

    Jikich, S.A.; McLendon, T.R.; Seshadri, K.S.; Irdi, G.A.; Smith, D.H.

    2007-11-01

    Measurements of sorption isotherms and transport properties of CO2 in coal cores are important for designing enhanced coalbed methane/CO2 sequestration field projects. Sorption isotherms measured in the lab can provide the upper limit on the amount of CO2 that might be sorbed in these projects. Because sequestration sites will most likely be in unmineable coals, many of the coals will be deep and under considerable lithostatic and hydrostatic pressures. These lithostatic pressures may significantly reduce the sorption capacities and/or transport rates. Consequently, we have studied apparent sorption and diffusion in a coal core under confining pressure. A core from the important bituminous coal Pittsburgh #8 was kept under a constant, three-dimensional external stress; the sample was scanned by X-ray computer tomography (CT) before, then while it sorbed, CO2. Increases in sample density due to sorption were calculated from the CT images. Moreover, density distributions for small volume elements inside the core were calculated and analyzed. Qualitatively, the computerized tomography showed that gas sorption advanced at different rates in different regions of the core, and that diffusion and sorption progressed slowly. The amounts of CO2 sorbed were plotted vs. position (at fixed times) and vs. time (for various locations in the sample). The resulting sorption isotherms were compared to isotherms obtained from powdered coal from the same Pittsburgh #8 extended sample. The results showed that for this single coal at specified times, the apparent sorption isotherms were dependent on position of the volume element in the core and the distance from the CO2 source. Also, the calculated isotherms showed that less CO2 was sorbed than by a powdered (and unconfined) sample of the coal. Changes in density distributions during the experiment were also observed. After desorption, the density distribution of calculated volume elements differed from the initial distribution

  8. Phospholipid Evidence for Methanogenic Archaea and Sulfate-reducing Bacteria in Coalbed Methane Wells in the Powder River Basin, Wyoming

    NASA Astrophysics Data System (ADS)

    Glossner, A.; Flores, R. M.; Mandernack, K.

    2008-12-01

    The Powder River Basin (PRB) comprises roughly 22,000 mi2 in northeastern Wyoming and southeastern Montana; it is a major source of coal and natural gas in the Rocky Mountain and Great Plains regions. The coalbed methane (CBM) produced from Paleocene Fort Union Formation coals in the PRB is thought primarily to be of bacterial origin due to its low δ13C values of -51 to -82 permil. Determination of the timing of methanogenesis, however, requires a methodology suitable for distinguishing viable methanogenic microorganisms. Here we provide evidence of living methanogenic Archaea and sulfate- reducing bacteria collected from co-produced water from CBM wells using phospholipid fatty acid (PLFA) and phospholipid ether lipid (PLEL) analyses. Twelve producing wells were sampled in May, 2007, using a high- pressure filtering apparatus. PLFAs were analyzed as fatty acid methyl esters and PLELs analyzed by their liberated core components using gas chromatography/mass spectrometry. Phospholipid analyses revealed an ecosystem dominated by Archaea, as the Archaeal isoprenoid, phytane, was the dominant phospholipid observed in nine of the wells sampled. Total microbial biomass estimates ranged from 1.1 ×106 cells/L to 8.3 ×107 cells/L, with the proportion of Archaeal cells ranging from 77.5 to 99.7 percent. In addition, the biomarkers 10me16:0, and cy17:0, considered to be biomarkers for genera of sulfate-reducing bacteria, were observed in several wells. The dominance of lipids from living Archaea in co- produced waters from CBM wells provides evidence supporting a recent origin of gas in the PRB coals.

  9. Tracking solutes and water from subsurface drip irrigation application of coalbed methane-produced waters, Powder River Basin, Wyoming

    USGS Publications Warehouse

    Engle, M.A.; Bern, C.R.; Healy, R.W.; Sams, J.I.; Zupancic, J.W.; Schroeder, K.T.

    2011-01-01

    One method to beneficially use water produced from coalbed methane (CBM) extraction is subsurface drip irrigation (SDI) of croplands. In SDI systems, treated CBMwater (injectate) is supplied to the soil at depth, with the purpose of preventing the buildup of detrimental salts near the surface. The technology is expanding within the Powder River Basin, but little research has been published on its environmental impacts. This article reports on initial results from tracking water and solutes from the injected CBM-produced waters at an SDI system in Johnson County, Wyoming. In the first year of SDI operation, soil moisture significantly increased in the SDI areas, but well water levels increased only modestly, suggesting that most of the water added was stored in the vadose zone or lost to evapotranspiration. The injectate has lower concentrations of most inorganic constituents relative to ambient groundwater at the site but exhibits a high sodium adsorption ratio. Changes in groundwater chemistry during the same period of SDI operation were small; the increase in groundwater-specific conductance relative to pre-SDI conditions was observed in a single well. Conversely, groundwater samples collected beneath another SDI field showed decreased concentrations of several constituents since the SDI operation.Groundwater-specific conductance at the 12 other wells showed no significant changes. Major controls on and compositional variability of groundwater, surface water, and soil water chemistry are discussed in detail. Findings from this research provide an understanding of water and salt dynamics associated with SDI systems using CBM-produced water. Copyright ??2011. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  10. Field-project designs for carbon dioxide sequestration and enhanced coalbed methane production

    SciTech Connect

    W. Neal Sams; Grant Bromhal; Sinisha Jikich; Turgay Ertekin; Duane H. Smith

    2005-12-01

    Worldwide concerns about global warming and possible contributions to it from anthropogenic carbon dioxide have become important during the past several years. Coal seams may make excellent candidates for CO{sub 2} sequestration; coal-seam sequestration could enhance methane production and improve sequestration economics. Reservoir-simulation computations are an important component of any engineering design before carbon dioxide is injected underground. We have performed such simulations for a hypothetical pilot-scale project in representative coal seams. In these simulations we assume four horizontal production wells that form a square, that is, two wells drilled at right angles to each other forming two sides of a square, with another pair of horizontal wells similarly drilled to form the other two sides. Four shorter horizontal wells are drilled from a vertical well at the center of the square, forming two straight lines orthogonal to each other. By modifying coal properties, especially sorption rate, we have approximated different types of coals. By varying operational parameters, such as injector length, injection well pressure, time to injection, and production well pressure, we can evaluate different production schemes to determine an optimum for each coal type. Any optimization requires considering a tradeoff between total CO{sub 2} sequestered and the rate of methane production. Values of total CO{sub 2} sequestered and methane produced are presented for multiple coal types and different operational designs. 30 refs., 11 figs., 1 tab.

  11. Controls on coalbed methane potential and gas sorption characteristics of high-volatile bituminous coals in Indiana

    NASA Astrophysics Data System (ADS)

    Solano-Acosta, Wilfrido

    The increasing demand for energy and a growing concern for global warming, owing in part to the steep rise in anthropogenic greenhouse gas emissions, have sparked worldwide interest in clean coal technologies. Although the energy potential of coal is large, there are many environmental concerns associated with its large-scale utilization. An alternative solution to increasing demand for energy is the recovery of coalbed methane (CBM), an efficient and clean fossil fuel associated with extensive coal deposits. CBM today represents nearly 10 percent of the energy consumed in the United States. From an environmental perspective, coal beds that are too deep or that contain low-quality coal are being investigated as potential sites for permanently sequestering carbon dioxide emissions (CO2 sequestration). Methane has been documented in coals of various ranks. The occurrence and distribution of economically recoverable quantities of CBM result from the interplay between stratigraphy, tectonics, and hydrology. This study evaluates geologic factors that control the occurrence of CBM in Indiana coals, ranging from large-scale processes (i.e., burial and fracturing) to molecular interactions between CBM and the physical structure of coal (i.e., gas adsorption). This study investigates the role of tectonics and burial in the formation of coal fracture sets (cleats) that are critical for CBM extraction. Based on field data, I investigate the role of fracturing with regard to gas occurrence and CBM producibility. The timing of cleat formation is evaluated via carbon and oxygen isotopic signatures of cleat-filling minerals. In addition to field-scale observations, this study includes an experimental component that, based on a multitude of laboratory data, constrains optimum conditions for coal-sample preservation prior to laboratory analyses for exploration. Chemical analyses, petrography, grain-size distributions, Fourier transform infra-red (FTIR) spectroscopy, pore

  12. Coal-bed methane development in Alabama. Biomonitoring of a produced water discharge from the Cedar Cove degasification field, Alabama. Final report, June 1986-December 1988

    SciTech Connect

    O'Neil, P.E.; Harris, S.C.; Drottar, K.R.; Mount, D.R.; Fillo, J.P.

    1989-06-01

    Stream discharge of a produced water generated by the coal-bed methane industry in Alabama was evaluated using instream biological studies in conjunction with whole-effluent toxicity testing. Instream biological studies included development of a concentration-response model of chloride effects to benthic invertebrate communities and long-term monitoring of both benthic invertebrates and fishes in Little Hurricane Creek. Results of the instream work identified limiting values of chloride below which no significant effects on instream benthic invertebrate communities were observed. Additionally, results of long-term monitoring for 1 year during controlled discharge of the produced water, indicated no significant effects to communities of fishes and benthic invertebrates resulting from this particular water. Aquatic toxicity testing was conducted to determine acute and chronic endpoints for standard test species and species occurring in Little Hurricane Creek. Results of the aquatic toxicity tests indicated that chloride accounted for all of the acute toxicity observed in Ceriodaphnia sp. whereas some chronic toxicity to Ceriodaphnia sp. was not explainable by chloride alone. The source of this chronic toxicity, beyond that explainable by chloride, is unknown at this time. The study provides a significant source of data for use in managing the discharge of coal-bed methane-produced waters.

  13. Effects of Coal-Bed Methane Discharge Waters on Soils and Vegetation Diversity

    NASA Astrophysics Data System (ADS)

    Stearns, M.; Tindall, J. A.; Friedel, M. J.; Cronin, G.; Berquist, E.

    2004-12-01

    Coal bed methane co-produced discharge waters in the Powder River Basin of Wyoming, resulting from extraction of methane from coal seams, have become a priority for chemical, hydrological and biological research during the last few years. Soil and vegetation samples were taken from impacted and reference sites (upland elevations and wetted gully) to investigate impacts of CBM discharge waters on soil physical and chemical properties and on native and introduced vegetation richness and diversity. Results indicate a significant increase of salinity and sodicity within local soil ecosystems at sites directly exposed to CBM discharge waters. Elevated concentrations of sodium in the soil appear to be due to consistent exposure to CBM waters. Clay-loam soils in the study area, which have a much larger specific surface area than the sandy soils, readily allow sodium ions to adsorb quickly to exchange sites. There was no significant relation between increasing water SAR values and increasing sediment SAR values downstream; however, soils exposed to the CBM water ranged from the moderate to severe SAR hazard index. Native vegetation species richness was highest at the reference (upland and gully) and impacted upland sites. The impacted gully had the greatest percent composition of introduced vegetation species. Salt-tolerant species had the greatest richness at the impacted gully, implicating a potential threat of invasion and competition to established native vegetation. CBM waters could have detrimental impacts to the local ecosystem, causing dispersion of soils and making it difficult for native vegetation to exist. These waters could also have a devastating effect on agricultural production operations and long-term water quality.

  14. Assessment of Spatial and Temporal Variation of Surface Water Quality in Streams Affected by Coalbed Methane Development

    NASA Astrophysics Data System (ADS)

    Chitrakar, S.; Miller, S. N.; Liu, T.; Caffrey, P. A.

    2015-12-01

    Water quality data have been collected from three representative stream reaches in a coalbed methane (CBM) development area for over five years to improve the understanding of salt loading in the system. These streams are located within Atlantic Rim development area of the Muddy Creek in south-central Wyoming. Significant development of CBM wells is ongoing in the study area. Three representative sampling stream reaches included the Duck Pond Draw and Cow Creek, which receive co-produced water, and; South Fork Creek, and upstream Cow Creek which do not receive co-produced water. Water samples were assayed for various parameters which included sodium, calcium, magnesium, fluoride, chlorine, nitrate, O-phosphate, sulfate, carbonate, bicarbonates, and other water quality parameters such as pH, conductivity, and TDS. Based on these water quality parameters we have investigated various hydrochemical and geochemical processes responsible for the high variability in water quality in the region. However, effective interpretation of complex databases to understand aforementioned processes has been a challenging task due to the system's complexity. In this work we applied multivariate statistical techniques including cluster analysis (CA), principle component analysis (PCA) and discriminant analysis (DA) to analyze water quality data and identify similarities and differences among our locations. First, CA technique was applied to group the monitoring sites based on the multivariate similarities. Second, PCA technique was applied to identify the prevalent parameters responsible for the variation of water quality in each group. Third, the DA technique was used to identify the most important factors responsible for variation of water quality during low flow season and high flow season. The purpose of this study is to improve the understanding of factors or sources influencing the spatial and temporal variation of water quality. The ultimate goal of this whole research is to

  15. Assessment of the Environmental Impacts of Coalbed Methane Development in the Powder River Basin - Use of Coalbead Methane Produced Water for Cropland Irrigation

    SciTech Connect

    Jeff Morris

    2009-01-30

    Water quality is a major concern with regard to development of coalbed methane (CBM) in the Powder River Basin, Wyoming. Large quantities of water are being produced and discharged as a by-product in the process of releasing natural gas from coal. Current practices of discharging large volumes of water into drainage channels or using it to irrigate cropland areas has the potential to elevate salinity and sodicity in soils. Elevated salinity affects the ability of plants to uptake water to facilitate biochemical processes such as photosynthesis and plant growth. Elevated sodicity in irrigation water adversely affects soil structure necessary for water infiltration, nutrient supply, and aeration. Salinity and sodicity concentrations are important in that a sodic soil can maintain its structure if the salinity level is maintained above the threshold electrolyte concentration. In this study, cropland soil and CBM water were treated with gypsum and sulfur. Changes in soil chemistry among different treatments were monitored using a split plot experiment. The CBM water used for irrigation had an EC of 1380 {micro}S cm{sup -1} and SAR of 24.3 mmol{sup 1/2} L{sup -1/2}. Baseline and post treatment soil samples were collected to a depth of 60 cm within each study plot, analyzed, and characterized for chemical parameters. Comparisons between Spring 2004 and Fall 2004 soil chemistry data after one irrigation season (using the equivalent of 1 month of irrigation water or {approx}12 inches) indicated that irrigating with Piney Creek water or a 50:50 blend of Piney Creek water and CBM water did not cause SAR values to increase. A combination of using a gypsum amendment to the soil along with a gypsum injection and sulfur burner treatment to the irrigation water resulted in the lowest SAR value in the first soil horizon among treatments irrigated solely with CBM produced water. The SAR value resulting from this combination treatment was 53% lower than using CBM water with no

  16. Field evaluation of gas-lift and progressive-cavity pumps as effective dewatering methods for coalbed methane wells. Final report, April 1984-December 1985

    SciTech Connect

    Graves, S.L.; Hollingsworth, F.C.; Beavers, W.M.

    1986-03-01

    Field evaluations of gas-lift and progressive-cavity pumps were conducted to determine their effectiveness as dewatering techniques for coalbed-methane wells in the Warrior Coal Field. AMPCO installed a gas-lift system in AMPCO Well No. 6. Problems included poor performance of all gas-lift valve designs and higher instantaneous water production rates than anticipated due to heading and unloading. The test provided the conclusion that gas lift is an effective start-up dewatering tool for initial removal of large amounts of water and solids but that in use as a long-term dewatering tool, needs additional evaluation relative to capital cost, valve design, and extended performance.

  17. Using a Watershed-Based Effluent Trading Approach to Manage Coalbed Methane Produced Water in a Cost-Effective and Environmentally Sound Manner

    NASA Astrophysics Data System (ADS)

    Wang, X.; Harju, J. A.; Bolles, B. A.

    2004-12-01

    Coalbed methane (CBM) is expected to supply much of the incremental U.S. natural gas demand in the coming decades. Extraction of methane from coal seams necessitates reduction of the hydrostatic pressure in the coalbed by removal of water, called produced water. The large volume of produced water not only raises concerns about its impact on surface water quality but also negatively affects producers' profitability because of costs associated with handling the water in a manner consistent with environmental regulatory requirements imposed by the Clean Water Act. Alternatively, watershed-based effluent trading could provide a market mechanism for managing CBM produced water and more quickly improving the overall water quality in a watershed at a lower cost. However, the complexity of appraising the potential trading options in accordance with the prerequisites of implementation feasibility and the effects on environment, economy, and equity dictates an easy-to-be-implemented tool. This paper presents a decision support tool that can be used by both water resources managers and other stakeholders to evaluate various trading options. The tool consists of a database on water quality and discharge baseline determined in terms of the U.S. Environmental Protection Agency's Total Maximum Daily Loads, algorithms to define trading types and trading and transferability rules, a SPARROW (SPAtially Referenced Regression On Watershed attributes) watershed model, a two-dimensional hydrodynamic water quality model, and a simplified economic model. These components are seamlessly integrated with ArcView GIS to facilitate use of this tool. In addition to the prototype developed for the Powder River Basin in Wyoming and Montana, this study formulates a general framework upon which similar tools can be created for other watersheds.

  18. Results of coalbed-methane drilling, Meadowfill Landfill, Harrison County, West Virginia: Chapter G.4 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ruppert, Leslie F.; Trippi, Michael H.; Fedorko, Nick; Grady, William C.; Eble, Cortland F.; Schuller, William A.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Methane contents of desorbed gas from coal samples in the Meadowfill Landfill study area ranged from 14.87 to 98.73 percent (corrected for air contamination) for the Harlem coal bed and Clarion coal zone, respectively. Proportions of methane to the sum of the higher molecular weight hydrocarbons ranged from about 40 to 340 as the desorbed gas contained only a small percentage of higher weight hydrocarbons. Coalbed methane from the Upper Kittanning upper split and the Upper Kittanning coal beds is thermogenic in origin with isotopic composition of carbon (carbon 13, 13C) in methane (expressed as δ13C in units of parts per thousand (per mil) relative to the Vienna Peedee belemnite (VPDB) standard) ranging from -46.6 to -48.7 per mil. Coalbed methane from the Brush Creek and Upper Freeport coal beds and the Clarion coal zone contains some biogenic methane with δ13C values ranging from -51.05 to -51.56 per mil.

  19. Effects of matrix shrinkage and swelling on the economics of enhanced-coalbed-methane production and CO{sub 2} sequestration in coal

    SciTech Connect

    Gorucu, F.B.; Jikich, S.A.; Bromhal, G.S.; Sams, W.N.; Ertekin, T.; Smith, D.H.

    2007-08-15

    In this work, the Palmer-Mansoori model for coal shrinkage and permeability increases during primary methane production was rewritten to also account for coal swelling caused by CO{sub 2} sorption. The generalized model was added to a compositional, dual porosity coalbed-methane reservoir simulator for primary (CBM) and ECBM production. A standard five-spot of vertical wells and representative coal properties for Appalachian coals was used. Simulations and sensitivity analyses were performed with the modified simulator for nine different parameters, including coal seam and operational parameters and economic criteria. The coal properties and operating parameters that were varied included Young's modulus, Poisson's ratio, cleat porosity, and injection pressure. The economic variables included CH{sub 4}, price, Col Cost, CO{sub 2} credit, water disposal cost, and interest rate. Net-present value (NPV) analyses of the simulation results included profits resulting from CH{sub 4}, production and potential incentives for sequestered CO{sub 2}, This work shows that for some coal seams, the combination of compressibility, cleat porosity, and shrinkage/swelling of the coal may have a significant impact on project economics.

  20. Reconnaissance shallow seismic investigation of depth-to-bedrock and possible methane-bearing coalbeds, Galena, Alaska

    USGS Publications Warehouse

    Stephenson, William J.; Williams, Robert A.; Odum, Jack K.; Worley, David M.; Barker, Charles E.; Clark, Arthur C.; Clough, James G.

    2002-01-01

    A reconnaissance shallow seismic reflection/refraction investigation in and around the city of Galena, Alaska suggests that Tertiary and/or Cretaceous bedrock, and possible coalbeds within the Cretaceous, is at least as deep as 550 feet in the immediate vicinity of town. Rock could be deeper than 1000 feet under alternate interpretations. Reflections recorded in these data are believed to be from the sediment/bedrock interface. Analysis of these reflections and associated refractions indicates that this interface, interpreted at most of the six profile locations, has a high seismic velocity, possibly indicating non-sedimentary rock (e.g. volcanic or igneous).

  1. Coalbed methane potential in the Appalachian states of Pennsylvania, West Virginia, Maryland, Ohio, Virginia, Kentucky, and Tennessee; an overview

    USGS Publications Warehouse

    Lyons, Paul C.

    1996-01-01

    This report focuses on the coalbed methane (CBM) potential of the central Appalachian basin (Virginia, eastern Kentucky, southern West Virginia, and Tennessee) and the northern Appalachian basin (Pennsylvania, northern West Virginia, Maryland, and Ohio). As of April 1996, there were about 800 wells producing CBM in the central and northern Appalachian basin. For the Appalchian basin as a whole (including the Cahaba coal field, Alabama, and excluding the Black Warrior Basin, Alabama), the total CBM production for 1992, 1993, 1994, and 1995, is here estimated at 7.77, 21.51, 29.99, and 32 billion cubic feet (Bcf), respectively. These production data compare with 91.38, 104.70, 110.70, and 112.11 Bcf, respectively, for the same years for the Black Warrior Basin, which is the second largest CBM producing basin in the United States. For 1992-1995, 92-95% of central and northern Appalachian CBM production came from southwestern Virginia, which has by far the largest CBM production the Appalachian states, exclusive of Alabama. For 1994, the average daily production of CBM wells in Virginia was 119.6 Mcf/day, which is about two to four times the average daily production rates for many of the CBM wells in the northern Appalachian basin. For 1992-1995, there is a clear increase in the percentage of CBM being produced in the central and northern Appalachian basin as compared with the Black Warrior Basin. In 1992, this percentage was 8% of the combined central and northern Appalachian and Black Warrior Basin CBM production as compared with 22% in 1995. These trends imply that the Appalachian states, except for Alabama and Virginia, are in their infancy with respect to CBM production. Total in place CBM resources in the central and northern Appalachian basin have been variously estimated at 66-76 trillion cubic feet (Tcf), of which an estimated 14.55 Tcf (3.07 Tcf for central Appalachian basin and 11.48 Tcf for northern Appalachian basin) is technically recoverable according to

  2. Hydrology of the Upper Cretaceous Fruitland Formation and the producibility of coal-bed methane, San Juan basin, Colorado and New Mexico

    SciTech Connect

    Kaiser, W.R. ); Swartz, T.E. )

    1990-05-01

    Fruitland coal seams contain 49 tcf of methane, which is produced from abnormally pressured coals in a variety of hydrologic settings. In a study funded by the Gas Research Institute, the authors calculated bottom-hole pressures from wellhead shut-in pressures to map hydraulic head and pressure regime, and estimated vertical pressure gradients to evaluate Fruitland hydrology and its relation to methane producibility. They inferred relative permeability from hydraulic head, pressure regime, and hydrochemistry, and related these hydrologic elements to established production. In the Fruitland Formation, coal seams are the primary aquifers, receiving recharge mainly from the elevated, wet, north and northwest margins of the basin. Formation waters in the north-central part of the basin have low chlorinities and high alkalinities, whereas those in the southern part of the basin are saline Na-Cl type similar to seawater. Regional discharge is to the San Juan River valley in the western part of the basin. Overpressuring in the north-central part of the basin is explained hydrodynamically and is attributed to artesian conditions. They infer enhanced coal-bed permeability where the potentiometric surface is flat and reduced permeability where it is steep. Overpressuring indicates enhanced permeability because permeability in coal seams is stress dependent. In the overpressured region, groundwater is fresh, indicative of an active, dynamic flow system and of permeable pathways. In contrast, connate seawater in the underpressured southern part of the basin implies negligible permeability; strata are too tight to accept and transmit measurable recharge. The basin's most productive coal bed-methane wells are overpressured and occur at hydrologic transitions from a flat to a steep potentiometric surface, overpressuring to underpressuring, and low- to high-chloride formation waters.

  3. Organic geochemical investigation and coal-bed methane characteristics of the Guasare coals (Paso Diablo mine, western Venezuela)

    USGS Publications Warehouse

    Quintero, K.; Martinez, M.; Hackley, P.; Marquez, G.; Garban, G.; Esteves, I.; Escobar, M.

    2011-01-01

    The aim of this work was to carry out a geochemical study of channel samples collected from six coal beds in the Marcelina Formation (Zulia State, western Venezuela) and to determine experimentally the gas content of the coals from the Paso Diablo mine. Organic geochemical analyses by gas chromatography-mass spectrometry and isotopic analyses on-line in coalbed gas samples were performed. The results suggest that the Guasare coals were deposited in a continental environment under highly dysoxic and low salinity conditions. The non-detection of 18??(H)-oleanane does not preclude that the organic facies that gave rise to the coals were dominated by angiosperms. In addition, the presence of the sesquiterpenoid cadalene may indicate the subordinate contribution of gymnosperms (conifers) in the Paleocene Guasare mire. The average coalbed gas content obtained was 0.6 cm3/g. ??13C and D values indicate that thermogenic gas is prevalent in the studied coals. Copyright ?? Taylor & Francis Group, LLC.

  4. Water quality and environmental isotopic analyses of ground-water samples collected from the Wasatch and Fort Union Formations in areas of coalbed methane development : implications to recharge and ground-water flow, eastern Powder River basin, Wyoming

    USGS Publications Warehouse

    Bartos, Timothy T.; Ogle, Kathy Muller

    2002-01-01

    Chemical analyses of ground-water samples were evaluated as part of an investigation of lower Tertiary aquifers in the eastern Powder River Basin where coalbed methane is being developed. Ground-water samples were collected from two springs discharging from clinker, eight monitoring wells completed in the Wasatch aquifer, and 13 monitoring or coalbed methane production wells completed in coalbed aquifers. The ground-water samples were analyzed for major ions and environmental isotopes (tritium and stable isotopes of hydrogen and oxygen) to characterize the composition of waters in these aquifers, to relate these characteristics to geochemical processes, and to evaluate recharge and ground-water flow within and between these aquifers. This investigation was conducted in cooperation with the Wyoming State Engineer's Office and the Bureau of Land Management. Water quality in the different aquifers was characterized by major-ion composition. Samples collected from the two springs were classified as calcium-sulfate-type and calcium-bicarbonate-type waters. All ground-water samples from the coalbed aquifers were sodium-bicarbonate-type waters as were five of eight samples collected from the overlying Wasatch aquifer. Potential areal patterns in ionic composition were examined. Ground-water samples collected during this and another investigation suggest that dissolved-solids concentrations in the coalbed aquifers may be lower south of the Belle Fourche River (generally less than 600 milligrams per liter). As ground water in coalbed aquifers flows to the north and northwest away from an inferred source of recharge (clinker in the study area), dissolved-solids concentrations appear to increase. Variation in ionic composition in the vertical dimension was examined qualitatively and statistically within and between aquifers. A relationship between ionic composition and well depth was noted and corroborates similar observations by earlier investigators in the Powder River

  5. A primer on the occurrence of coalbed methane in low-rank coals, with special reference to its potential occurrence in Pakistan

    USGS Publications Warehouse

    SanFilipo, John R.

    2000-01-01

    Introduction: This report compiles and updates a series of correspondence that took place between 1998 and early 2000 among the author and representatives of various consulting groups operating in the coal sector of Pakistan. The purpose of the original correspondence was to introduce basic concepts of coalbed methane (CBM) in low-rank coals to planners and other parties interested in the development of Pakistan's coal, particularly the large deposits of the Thar desert area of Sindh Province that were recently discovered (SanFilipo and Khan, 1994) by the Geological Survey of Pakistan (GSP) and the U.S. Geological Survey (USGS). The author tested two shallow boreholes in Sindh Province for CBM in 1992, including one in Thar, with very marginal results. Additional targets with better CBM prospects were recommended shortly thereafter (SanFilipo and others, 1994), but these were not followed up during subsequent drilling, nor were any other sites tested. Recent events, notably the rapid pace of CBM development in low-rank coals of the Powder River Basin of the U.S., and a show of CBM in commercial quantities in the Cambay Basin of India - both of which are similar in age and rank to most of Pakistan's coal - have indicated a need for reevaluating the initial CBM investigations made in Pakistan in 1992 and for a reassessment of the CBM prospects for the country at large.

  6. Coalbed-methane production in the Appalachian basin: Chapter G.2 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Milici, Robert C.; Polyak, Désirée E.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Coalbed methane (CBM) occurs in coal beds of Mississippian and Pennsylvanian (Carboniferous) age in the northern, central, and southern Appalachian basin coal regions, which extend almost continuously from Pennsylvania southward to Alabama. Most commercial CBM production in the Appalachian basin is from three structural subbasins: (1) the Dunkard basin in Pennsylvania, Ohio, and northern West Virginia; (2) the Pocahontas basin in southern West Virginia, eastern Kentucky, and southwestern Virginia; and (3) part of the Black Warrior basin in Alabama. The cumulative CBM production in the Dunkard basin through 2005 was 17 billion cubic feet (BCF), the production in the Pocahontas basin through 2006 was 754 BCF, and the production in the part of the Black Warrior basin in Alabama through 2007 was 2.008 TCF. CBM development may be regarded as mature in Alabama, where annual production from 1998 through 2007 was relatively constant and ranged from 112 to 121 BCF. An opportunity still exists for additional growth in the Pocahontas basin. In 2005, annual CBM production in the Pocahontas basin in Virginia and West Virginia was 85 BCF. In addition, opportunities are emerging for producing the large, diffuse CBM resources in the Dunkard basin as additional wells are drilled and technology improves.

  7. 3D Geological Modeling of CoalBed Methane (CBM) Resources in the Taldykuduk Block Karaganda Coal Basin, Kazakhstan

    NASA Astrophysics Data System (ADS)

    Sadykov, Raman; Kiponievich Ogay, Evgeniy; Royer, Jean-Jacques; Zhapbasbayev, Uzak; Panfilova, Irina

    2015-04-01

    Coal Bed Methane (CBM) is gas stored in coal layers. It can be extracted from wells after hydraulic fracturing and/or solvent injection, and secondary recovery techniques such as CO2 injection. Karaganda Basin is a very favorable candidate region to develop CBM production for the following reasons: (i) Huge gas potential; (ii) Available technologies for extracting and commercializing the gas produced by CBM methods; (iii) Experience in degassing during underground mining operations for safety reasons; (iv) Local needs in energy for producing electricity for the industrial and domestic market. The objectives of this work are to model the Taldykuduk block coal layers and their properties focusing on Coal Bed Methane production. It is motivated by the availability of large coal bed methane resources in Karaganda coal basin which includes 4 300 Bm3 equivalent 2 billion tons of coal (B = billion = 109) with gas content 15-25 m3/t of coal (for comparison San Juan basin (USA) has < 20 m3/t). The CBM reserves estimations are about: Saransk block, 26.3 Bm3 and Taldykuduk block, 23.5 Bm3. Methane (CH4) can be considered as an environmentally-friendly fuel compared to coal. Actually, the methane extracted during mining is released in the atmosphere, collecting it for recovering energy will reduce CO2 equivalent emissions by 36 Mt, good news regarding climate warming issues. The exploitation method will be based on a EOR technology consisting in injecting CO2 which replaces methane in pores because it has a higher adsorption capacity than CH4; exploiting CBM by CO2 injection provides thus a safe way to sequestrate CO2 in adsorbed form. The 3D geological model was built on Gocad/Skua using the following available data set: 926 wells and large area (7 x 12 km). No seismic data; coal type and chemical components (S, ash, …); unreliable available cross-section & maps due to old acquisition; quality mature coal; complex heterogeneous fractures network reported on geological cross

  8. Research on sequence stratigraphy, hydrogeological units and commingled drainage associated with coalbed methane production: a case study in Zhuzang syncline of Guizhou province, China

    NASA Astrophysics Data System (ADS)

    Li, Xin; Fu, Xuehai; Ge, Yanyan; Chang, Xixi

    2016-08-01

    Exploitation of coalbed methane (CBM) involves groundwater extraction to depressurize coal reservoirs. This can involve groundwater extraction from multiple coal seams (commingled drainage). Interlayer interferences, caused by heterogeneity of hydrodynamic fields of the different coal gas reservoirs, can restrain CBM production. Understanding of the hydrogeological characteristics of each reservoir, inseparable from characteristics of the sequence stratigraphic framework, is critical for CBM exploration. Analysis of Zhuzang syncline in Guizhou province, China, found gas- and water-blocking strata near the maximum flooding surface in the upper part of each third-order stratigraphic sequence; thus, the hydrogeological units were divided vertically (SQ4, SQ3, SQ2 and SQ1) by the boundaries of the third-order sequence. The commingled-drainage CBM wells were analyzed by numerical simulation and Extenics theory, on the basis of characteristics of the hydrogeological units. Gas content, reservoir pressure and hydrodynamic parameters were found to vary between the hydrogeological units. The interlayer interference was not obvious where there was commingled drainage within single hydrogeological units with similar hydrodynamic force; this was validated by observing the consistent pressure decrease within each reservoir using historical matching. Since the source of drainage water varied from stratum SQ3 to SQ4 (containing lower hydrodynamic force compared to SQ3), it was obvious that groundwater extraction from SQ4 was restrained by SQ3, by showing obvious interlayer interference and restrained CBM production during commingled drainage across the different hydrogeological units. Reservoirs within each single hydrogeological unit tend to obtain higher CBM yield, thus take priority for commingled drainage.

  9. Hydraulic fracturing and wellbore completion of coalbed methane wells in the Powder River Basin, Wyoming: Implications for water and gas production

    SciTech Connect

    Colmenares, L.B.; Zoback, M.D.

    2007-01-15

    Excessive water production (more than 7000 bbl/month per well) from many coalbed methane (CBM) wells in the Powder River Basin of Wyoming is also associated with significant delays in the time it takes for gas production to begin. Analysis of about 550 water-enhancement activities carried out during well completion demonstrates that such activities result in hydraulic fracturing of the coal. Water-enhancement activities, consists of pumping 60 bbl of water/min into the coal seam during approximately 15 min. This is done to clean the well-bore and to enhance CBM production. Hydraulic fracturing is of concern because vertical hydraulic fracture growth could extend into adjacent formations and potentially result in excess CBM water production and inefficient depressurization of coals. Analysis of the pressure-time records of the water-enhancement tests enabled us to determine the magnitude of the least principal stress (S{sub 3}) in the coal seams of 372 wells. These data reveal that because S{sub 3} switches between the minimum horizontal stress and the overburden at different locations, both vertical and horizontal hydraulic fracture growth is inferred to occur in the basin, depending on the exact location and coal layer. Relatively low water production is observed for wells with inferred horizontal fractures, whereas all of the wells associated with excessive water production are characterized by inferred vertical hydraulic fractures. The reason wells with exceptionally high water production show delays in gas production appears to be inefficient depressurization of the coal caused by water production from the formations outside the coal. To minimize CBM water production, we recommend that in areas of known vertical fracture propagation, the injection rate during the water-enhancement tests should be reduced to prevent the propagation of induced fractures into adjacent water-bearing formations.

  10. Effects of Adsorbed Gases on the Physical and Transport Properties of Low-Rank Coal, PRB, WY: Implications for Carbon Sequestration and Enhanced Coalbed Methane Recovery

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Zoback, M. D.; Hagin, P. N.

    2010-12-01

    When CO2 is injected into unminable coalbeds, it has the potential to enhance the amount of methane production (ECBM) and to geologically sequester CO2 as an adsorbed phase. In this study we study the effects of adsorption of He, N2, CH4 and CO2, on the mechanical and flow properties of sub-bituminous coal from the Powder River Basin (PRB) on both intact and crushed samples. The coal samples were vacuum dried before each test, then saturated by each test gas at a series of either increasing pore pressure or increasing effective stress until steady state was reached. Thus, the amount of adsorption can be measured as a function of pore pressure Permeability was measured as a function of effective stress. Preliminary results show that the adsorption of CO2 is twice as large as CH4, and almost four times that of N2. Hysteresis is observed among pure component adsorption and desorption isotherms which are characterized Langmuir-type adsorption isotherms. Permeability decreases with increasing effective stress for He, CH4 and CO2. At constant effective stress, permeability decreases when the saturating gas changes from He to CH4 and CO2. Hysteresis of permeability with increasing and decreasing effective stress is not observed in crushed samples. The coal swells when CH4 displaces He and swells more when CO2 displaces He. Viscoplastic creep behavior is observed in the presence of CH4 and CO2 with both intact and crushed samples, which may affect maintaining permeability for long-term CO2 injection. Adsorption Isotherm of Crushed Coal Sample, WY Permeability as a function of effective stress with different gas saturation

  11. Reuse of Produced Water from CO2 Enhanced Oil Recovery, Coal-Bed Methane, and Mine Pool Water by Coal-Based Power Plants

    SciTech Connect

    Knutson, Chad; Dastgheib, Seyed A.; Yang, Yaning; Ashraf, Ali; Duckworth, Cole; Sinata, Priscilla; Sugiyono, Ivan; Shannon, Mark A.; Werth, Charles J.

    2012-07-01

    Power generation in the Illinois Basin is expected to increase by as much as 30% by the year 2030, and this would increase the cooling water consumption in the region by approximately 40%. This project investigated the potential use of produced water from CO2 enhanced oil recovery (CO2-EOR) operations; coal-bed methane (CBM) recovery; and active and abandoned underground coal mines for power plant cooling in the Illinois Basin. Specific objectives of this project were: (1) to characterize the quantity, quality, and geographic distribution of produced water in the Illinois Basin; (2) to evaluate treatment options so that produced water may be used beneficially at power plants; and (3) to perform a techno-economic analysis of the treatment and transportation of produced water to thermoelectric power plants in the Illinois Basin. Current produced water availability within the basin is not large, but potential flow rates up to 257 million liters per day (68 million gallons per day (MGD)) are possible if CO2-enhanced oil recovery and coal bed methane recovery are implemented on a large scale. Produced water samples taken during the project tend to have dissolved solids concentrations between 10 and 100 g/L, and water from coal beds tends to have lower TDS values than water from oil fields. Current pretreatment and desalination technologies including filtration, adsorption, reverse osmosis (RO), and distillation can be used to treat produced water to a high quality level, with estimated costs ranging from $2.6 to $10.5 per cubic meter ($10 to $40 per 1000 gallons). Because of the distances between produced water sources and power plants, transportation costs tend to be greater than treatment costs. An optimization algorithm was developed to determine the lowest cost pipe network connecting sources and sinks. Total water costs increased with flow rate up to 26 million liters per day (7 MGD), and the range was from $4 to $16 per cubic meter

  12. Diagenetic mineralization in Pennsylvanian coals from Indiana, USA: 13C/12C and 18O/16O implications for cleat origin and coalbed methane generation

    USGS Publications Warehouse

    Solano-Acosta, W.; Schimmelmann, A.; Mastalerz, Maria; Arango, I.

    2008-01-01

    Cleats and fractures in southwestern Indiana coal seams are often filled with authigenic kaolinite and/or calcite. Carbon- and oxygen-stable isotope ratios of kaolinite, calcite, and coalbed CO2 were evaluated in combination with measured values and published estimates of ??18O of coalbed paleowaters that had been present at the time of mineralization. ??18Omineral and ??18Owater values jointly constrain the paleotemperature of mineralization. The isotopic evidence and the thermal and tectonic history of this part of the Illinois Basin led to the conclusion that maximum burial and heat-sterilization of coal seams approximately 272??Ma ago was followed by advective heat redistribution and concurrent precipitation of kaolinite in cleats at a burial depth of < 1600??m at ??? 78 ?? 5????C. Post-Paleozoic uplift, the development of a second generation of cleats, and subsequent precipitation of calcite occurred at shallower burial depth between ??? 500 to ??? 1300??m at a lower temperature of 43 ?? 6????C. The available paleowater in coalbeds was likely ocean water and/or tropical meteoric water with a ??18Owater ??? - 1.25??? versus VSMOW. Inoculation of coalbeds with methanogenic CO2-reducing microbes occurred at an even later time, because modern microbially influenced 13C-enriched coalbed CO2 (i.e., the isotopically fractionated residue of microbial CO2 reduction) is out of isotopic equilibrium with 13C-depleted calcite in cleats. ?? 2007 Elsevier B.V. All rights reserved.

  13. Assessments of Environmental Impacts and Beneficial Use of Coalbed Methane Produced Water in the Powder River Basin

    SciTech Connect

    Jeff Morris

    2009-03-15

    Impact on water quality and the beneficial use of the coal bed methane (CBM) produced water are imminent questions to be answered due to the rapidly growing CBM exploration in the Powder River Basin (PRB). The practice of discharging large volumes of water into drainage channels or using it to irrigate rangeland areas has the potential of causing serious problems. The elevated salinity and sodicity in the CBM water may be detrimental to soils, plants and the associated microbial communities. There are limited studies on CBM water characterization; however, a comprehensive understanding of CBM water influence on the local ecosystem is lacking. It is very important that the water applied to soils meets the favorable combination of salinity and sodicity that will allow the plants to grow at good production levels and that will maintain the structure of the soils. The purpose of this study was to access various CBM water treatment technologies and the influence of the treated water on local biogeochemical settings in order to evaluate and identify the proper technologies to treat the CBM produced water from CBM operations, and use it in an environmentally safe manner. Unfortunately, a suitable field site was not identified and the funds for this effort were moved to a different project.

  14. Characteristic of In Situ Stress and Its Control on the Coalbed Methane Reservoir Permeability in the Eastern Margin of the Ordos Basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Junlong; Tang, Dazhen; Xu, Hao; Li, Yong; Li, Song; Tao, Shu; Lin, Wenji; Liu, Zhenxing

    2016-08-01

    Coalbed methane (CBM) development faces many challenges, among which in situ stress and permeability are two of the most important and fundamental factors. Knowledge of the characteristics of these factors is crucial to CBM exploration and development. Based on measured injection/falloff and in situ stress well test data of 55 CBM wells in the eastern margin of the Ordos Basin, correlations between parameters including initial reservoir pressure, in situ stress, lateral stress coefficient, well test permeability, and burial depth were determined. The distribution of in situ stress was analyzed systematically and its influence on permeability was also addressed. The results indicate that the maximum horizontal principal stress ( σ H 10.13-37.84 MPa, average 22.50 MPa), minimum horizontal principal stress ( σ h 6.98-26.88 MPa, average 15.04 MPa) and vertical stress ( σ v 12.30-35.72 MPa, average 22.48 MPa) all have positive correlations with coal burial depth. Stress ratios ( σ H/ σ h, σ H/ σ v, and σ h/ σ v) and lateral stress coefficient slowly attenuated with depth. With increase of horizontal principal stresses, coal reservoir permeability (0.01-3.33 mD, average 0.65 mD) decreases. The permeability variation is basically consistent with change of stress state at a certain burial depth, the essence of which is the deformation and destruction of coal pore structures under the action of stresses. Three types of stress fields exist in the area: in the shallow coal seam at burial depths <700 m, the horizontal principal stress is dominant, revealing a strike slip regime ( σ H > σ v > σ h), with average permeability 0.89 mD; from 700 to 1000 m depths, there is a stress transition zone ( σ H ≈ σ v > σ h) with average permeability 0.73 mD; in the deep coal seam with burial depths >1000 m, the vertical principal stress is dominant, demonstrating a normal stress regime ( σ v > σ H > σ h) with average permeability 0.11 mD.

  15. Geologic cross section, gas desorption, and other data from four wells drilled for Alaska rural energy project, Wainwright, Alaska, coalbed methane project, 2007-2009

    USGS Publications Warehouse

    Clark, Arthur C.; Roberts, Stephen B.; Warwick, Peter D.

    2010-01-01

    Energy costs in rural Alaskan communities are substantial. Diesel fuel, which must be delivered by barge or plane, is used for local power generation in most off-grid communities. In addition to high costs incurred for the purchase and transport of the fuel, the transport, transfer, and storage of fuel products pose significant difficulties in logistically challenging and environmentally sensitive areas. The Alaska Rural Energy Project (AREP) is a collaborative effort between the United States Geological Survey (USGS) and the Bureau of Land Management Alaska State Office along with State, local, and private partners. The project is designed to identify and evaluate shallow (<3,000 ft) subsurface resources such as coalbed methane (CBM) and geothermal in the vicinity of rural Alaskan communities where these resources have the potential to serve as local-use power alternatives. The AREP, in cooperation with the North Slope Borough, the Arctic Slope Regional Corporation, and the Olgoonik Corporation, drilled and tested a 1,613 ft continuous core hole in Wainwright, Alaska, during the summer of 2007 to determine whether CBM represents a viable source of energy for the community. Although numerous gas-bearing coal beds were encountered, most are contained within the zone of permafrost that underlies the area to a depth of approximately 1,000 ft. Because the effective permeability of permafrost is near zero, the chances of producing gas from these beds are highly unlikely. A 7.5-ft-thick gas-bearing coal bed, informally named the Wainwright coal bed, was encountered in the sub-permafrost at a depth of 1,242 ft. Additional drilling and testing conducted during the summers of 2008 and 2009 indicated that the coal bed extended throughout the area outlined by the drill holes, which presently is limited to the access provided by the existing road system. These tests also confirmed the gas content of the coal reservoir within this area. If producible, the Wainwright coal bed

  16. Subsurface Drip Irrigation As a Methold to Beneficiallly Use Coalbed Methane Produced Water: Initial Impacts to Groundwater, Soil Water, and Surface Water

    SciTech Connect

    Engle, M.A.: Bern, C: Healy, R: Sams, J: Zupancic, J.: Schroeder, K.

    2009-10-18

    Coalbed methane (CBM) currently accounts for >8% of US natural gas production. Compared to traditional sources, CBM co-produces large volumes of water. Of particular interest is CBM development in the Powder River Basin of Wyoming and Montana, the 2nd largest CBM production field in the US, where CBM produced waters exhibit low to moderate TDS and relatively high sodium-adsorption ratio (SAR) that could potentially impact the surface environment. Subsurface drip irrigation (SDI) is an emerging technology for beneficial use of pre-treated CBM waters (injectate) which are emitted into the root zone of an agricultural field to aid in irrigation. The method is designed to minimize environmental impacts by storing potentially detrimental salts in the vadose zone. Research objectives include tracking the transport and fate of the water and salts from the injected CBM produced waters at an SDI site on an alluvial terrace, adjacent to the Powder River, Johnson County, Wyoming. This research utilizes soil science, geochemical, and geophysical methods. Initial results from pre-SDI data collection and the first 6-months of post-SDI operation will be presented. Substantial ranges in conductivity (2732-9830 {micro}S/cm) and dominant cation chemistry (Ca-SO{sub 4} to Na-SO{sub 4}) have been identified in pre-SDI analyses of groundwater samples from the site. Ratios of average composition of local ground water to injectate demonstrate that the injectate contains lower concentrations of most constituents except for Cr, Zn, and Tl (all below national water quality standards) but exhibits a higher SAR. Composition of soil water varies markedly with depth and between sites, suggesting large impacts from local controls, including ion exchange and equilibrium with gypsum and carbonates. Changes in chemical composition and specific conductivity along surface water transects adjacent to the site are minimal, suggesting that discharge to the Powder River from groundwater underlying the

  17. Potential water-quality effects of coal-bed methane production water discharged along the upper Tongue River, Wyoming and Montana

    USGS Publications Warehouse

    Kinsey, Stacy M.; Nimick, David A.

    2011-01-01

    Water quality in the upper Tongue River from Monarch, Wyoming, downstream to just upstream from the Tongue River Reservoir in Montana potentially could be affected by discharge of coal-bed methane (CBM) production water (hereinafter referred to as CBM discharge). CBM discharge typically contains high concentrations of sodium and other ions that could increase dissolved-solids (salt) concentrations, specific conductance (SC), and sodium-adsorption ratio (SAR) in the river. Increased inputs of sodium and other ions have the potential to alter the river's suitability for agricultural irrigation and aquatic ecosystems. Data from two large tributaries, Goose Creek and Prairie Dog Creek, indicate that these tributaries were large contributors to the increase in SC and SAR in the Tongue River. However, water-quality data were not available for most of the smaller inflows, such as small tributaries, irrigation-return flows, and CBM discharges. Thus, effects of these inflows on the water quality of the Tongue River were not well documented. Effects of these small inflows might be subtle and difficult to determine without more extensive data collection to describe spatial patterns. Therefore, synoptic water-quality sampling trips were conducted in September 2005 and April 2006 to provide a spatially detailed profile of the downstream changes in water quality in this reach of the Tongue River. The purpose of this report is to describe these downstream changes in water quality and to estimate the potential water-quality effects of CBM discharge in the upper Tongue River. Specific conductance of the Tongue River through the study reach increased from 420 to 625 microsiemens per centimeter (.μS/cm; or 49 percent) in the downstream direction in September 2005 and from 373 to 543 .μS/cm (46 percent) in April 2006. Large increases (12 to 24 percent) were measured immediately downstream from Goose Creek and Prairie Dog Creek during both sampling trips. Increases attributed to

  18. Chemical and stable isotopic evidence for water/rock interaction and biogenic origin of coalbed methane, Fort Union Formation, Powder River Basin, Wyoming and Montana U.S.A

    USGS Publications Warehouse

    Rice, C.A.; Flores, R.M.; Stricker, G.D.; Ellis, M.S.

    2008-01-01

    Significant amounts (> 36??million m3/day) of coalbed methane (CBM) are currently being extracted from coal beds in the Paleocene Fort Union Formation of the Powder River Basin of Wyoming and Montana. Information on processes that generate methane in these coalbed reservoirs is important for developing methods that will stimulate additional production. The chemical and isotopic compositions of gas and ground water from CBM wells throughout the basin reflect generation processes as well as those that affect water/rock interaction. Our study included analyses of water samples collected from 228 CBM wells. Major cations and anions were measured for all samples, ??DH2O and ??18OH2O were measured for 199 of the samples, and ??DCH4 of gas co-produced with water was measured for 100 of the samples. Results show that (1) water from Fort Union Formation coal beds is exclusively Na-HCO3-type water with low dissolved SO4 content (median < 1??mg/L) and little or no dissolved oxygen (< 0.15??mg/L), whereas shallow groundwater (depth generally < 120??m) is a mixed Ca-Mg-Na-SO4-HCO3 type; (2) water/rock interactions, such as cation exchange on clay minerals and precipitation/dissolution of CaCO3 and SO4 minerals, account for the accumulation of dissolved Na and depletion of Ca and Mg; (3) bacterially-mediated oxidation-reduction reactions account for high HCO3 (270-3310??mg/L) and low SO4 (median < 0.15??mg/L) values; (4) fractionation between ??DCH4 (- 283 to - 328 per mil) and ??DH2O (- 121 to - 167 per mil) indicates that the production of methane is primarily by biogenic CO2 reduction; and (5) values of ??DH2O and ??18OH2O (- 16 to - 22 per mil) have a wide range of values and plot near or above the global meteoric water line, indicating that the original meteoric water has been influenced by methanogenesis and by being mixed with surface and shallow groundwater.

  19. Coal seam methane is one of the hotter current plays

    SciTech Connect

    Crouse, P.C. )

    1989-11-01

    The author discusses how exploitation and development of coal seams for methane gas recovery has caught the fancy of the petroleum industry. This resource has the potential to add trillions of cubic feet of marketable gas in the future. Shallow coalbed provinces are estimated to constitute around a 400 to 900-Tcf resource with 10 to 100 Tcf of potentially recoverable reserves. Current U.S. gas reserves are 168 Tcf, excluding Alaska (25 Tcf). Coalbed methane resources occur over a large portion of the United States with 37 states containing some amount of coalbed methane. The author shows the major provinces for coalbed methane.

  20. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-06-15

    predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, two-dimensional cubic equations of state, and the local density model. In general, all models performed well for Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). However, for pressures higher than 8.3 MPa (1200 psia), carbon dioxide produced multilayer adsorption behavior similar to Type IV adsorption. Our results to date indicate that the SLD model may be a suitable choice for modeling multilayer coalbed gas adsorption. However, model improvements are required to (a) account for coal heterogeneity and structure complexity, and (b) provide for more accurate density predictions. (3) Coal Characterization: We have identified several well-characterized coals for use in our adsorption studies. The criteria for coal selection has been guided by the need for coals that (a) span the spectrum of properties encountered in coalbed methane production (such as variation in rank), and (b) originate from coalbed methane recovery sites (e.g., San Juan Basin, Black Warrior Basin, etc.). At Pennsylvania State University, we have completed calibrating our instruments using a well-characterized activated carbon. In addition, we have conducted CO{sub 2} and methane uptakes on four samples, including (a) a widely used commercial activated carbon, BPL from Calgon Carbon Corp.; (b) an Illinois No.6 bituminous coal from the Argonne Premium Coal sample bank; (c) a Fruitland Intermediate coal sample; (d) a dry Fruitland sample. The results are as expected, except for a greater sensitivity to the outgassing temperature. ''Standard'' outgassing conditions (e.g., 383.2 K, overnight), which are often used, may not be appropriate for gas storage in coalbeds. Conditions that are more representative of in-situ coal (approximately 313.2 K) may be much more appropriate. In addition, our results highlight the importance of assessing the degree

  1. Coalbed gas in the Mecsek Basin, Hungary

    USGS Publications Warehouse

    Landis, E.R.; Rohrbacher, T.J.; Barker, C.E.; Fodor, B.; Gombar, G.

    2003-01-01

    Information about the presence and recovery of coalbed gas during underground mining and attempts to recover the gas as an energy source, plus new data about gas storage capacity, petrography, maturity, and other coal quality factors, indicate that the coals of the Mecsek Basin may contain large quantities of coalbed gas that is largely methane. Two preliminary estimates of the total gas content of the coalfield are 0.28e+11 m3 (almost 1 trillion cubic feet) and 1.13e+11 m3 (nearly 4 trillion cubic feet). Although much more information is needed about gas contents, permeabilities and other reservoir factors, the available geologic information may be sufficient to identify target areas for exploration. Efforts required to evaluate production potential are warranted. ?? 2003 Elsevier Science B.V. All rights reserved.

  2. Suppressed vitrinite reflectance in the Ferron coalbed gas fairway, central Utah: Possible influence of overpressure

    USGS Publications Warehouse

    Quick, J.C.; Tabet, D.E.

    2003-01-01

    Chemical and thermoplastic properties of coals in the Ferron coalbed methane fairway indicate that coals in the north are of higher rank than coals in the south. Measured vitrinite reflectance does not accurately show this variation of coal rank. Although vitrinite reflectance in the southern and central part of the fairway is consistent with other measures of coal rank, suppressed vitrinite reflectance is observed in the north where methane contents are relatively high. This coincidence of suppressed reflectance and relatively high coalbed methane yields may be significant. We speculate that the suppressed reflectance values result from a burial history where overpressure developed during the early stages of coalification and persisted until recent uplift and cooling; such instances may be diagnostic of prospective coalbed methane targets elsewhere. ?? 2003 Published by Elsevier B.V.

  3. Project identification for methane reduction options

    SciTech Connect

    Kerr, T.

    1996-12-31

    This paper discusses efforts directed at reduction in emission of methane to the atmosphere. Methane is a potent greenhouse gas, which on a 20 year timeframe may present a similar problem to carbon dioxide. In addition, methane causes additional problems in the form of smog and its longer atmospheric lifetime. The author discusses strategies for reducing methane emission from several major sources. This includes landfill methane recovery, coalbed methane recovery, livestock methane reduction - in the form of ruminant methane reduction and manure methane recovery. The author presents examples of projects which have implemented these ideas, the economics of the projects, and additional gains which come from the projects.

  4. Development of an instream bioassessment methodology for the surface disposal of coalbed methane produced waters. Topical report, January-December 1991

    SciTech Connect

    O'Neil, P.E.; Harris, S.C.

    1992-10-01

    The goal of the study was to develop and evaluate an instream monitoring methodology for the disposal of produced waters within guidelines of the water quality-based approach for the discharge of effluents. The methodology was developed using produced waters derived from the production of methane from coal seams in Alabama. Research efforts during 1991 focused on development and testing of an instream bioassessment procedure to be used for determining if discharged produced water effluents cause biological impairment within the receiving stream. Development of this particular procedure is important because regulations governing effluents are becoming more protective of the total instream environment, as opposed to strictly water quality, and methods are being proposed by the U.S. Environmental Protection Agency (USEPA) for use by industry and the states to this end. The bioassessment procedure outlined in the paper documents a sampling methodology that can be followed to determine if a discharged effluent is having a statistically significant effect on the structure of benthic macroinvertebrate communities downstream of a permitted discharge point.

  5. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects listed above, also

  6. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2003-03-10

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The originally-stated, major objectives of the current project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project has developed, an important additional objective has been added to the above original list. Namely, we have been encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we have participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects

  7. Interconnecting compressors control coalbed gas production

    SciTech Connect

    Payton, R.; Niederhofer, J. )

    1992-10-05

    This paper reports that centralized compressors afford Taurus Exploration Inc.'s coalbed gas operations optimum control of gas production. Unlike satellite stations, the centralized system allows methane gas to e shifted from station to station via the interconnecting low-pressure pipeline network. The operations area encompasses approximately 40,000 acres, about 40 miles southwest of Birmingham, Ala. The project includes about 250-miles of low-pressure gas flow lines to almost 400 wells. The centralized system is less costly than a satellite station to build and operate. Unlike a satellite station that requires each compressor to have a complete set of ancillary equipment, the centralized system requires only one suction manifold, one dehydration setup, and one metering facility for every five compressor sets.

  8. Methane drainage with horizontal boreholes in advance of longwall mining: an analysis. Final report

    SciTech Connect

    Gabello, D.P.; Felts, L.L.; Hayoz, F.P.

    1981-05-01

    The US Department of Energy (DOE) Morgantown Energy Technology Center has implemented a comprehensive program to demonstrate the technical and economic viability of coalbed methane as an energy resource. The program is directed toward solution of technical and institutional problems impeding the recovery and use of large quantities of methane contained in the nation's minable and unminable coalbeds. Conducted in direct support of the DOE Methane Recovery from Coalbeds Project, this study analyzes the economic aspects of a horizontal borehole methane recovery system integrated as part of a longwall mine operation. It establishes relationships between methane selling price and annual mine production, methane production rate, and the methane drainage system capital investment. Results are encouraging, indicating that an annual coal production increase of approximately eight percent would offset all associated drainage costs over the range of methane production rates and capital investments considered.

  9. Methane production from coal by a single methanogen

    NASA Astrophysics Data System (ADS)

    Mayumi, Daisuke; Mochimaru, Hanako; Tamaki, Hideyuki; Yamamoto, Kyosuke; Yoshioka, Hideyoshi; Suzuki, Yuichiro; Kamagata, Yoichi; Sakata, Susumu

    2016-10-01

    Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface–derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this “methoxydotrophic” mode of methanogenesis couples O-demethylation, CO2 reduction, and possibly acetyl–coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

  10. Phase states of methane in fossil coals

    NASA Astrophysics Data System (ADS)

    Alexeev, A. D.; Vasylenko, T. A.; Ul'yanova, E. V.

    2004-06-01

    NMR measurements have revealed that methane can exist in coal samples in the state of solid solution rather than only adsorbed gas, opening new ways to prevention of gas dynamic accidents in underground coal mines and true estimation of coalbed methane resources. Understanding molecular structure of coal constituents and forms of methane occurrence in coal is the only way of extracting safely either coal or methane. We had studied nuclear magnetic resonance lines in various coals at room or low temperatures and have found that there exist three species of methane molecules differing in molecular mobility. Based on estimated diffusion parameters, these species were attributed to free methane, adsorbed methane, and solid solution of methane in crystalline coal substance. While first two phases are well known and can be analyzed by many different techniques, the last one hardly can be studied by methods other than NMR, resulting in inadequate estimations of methane resources.

  11. Characterization of the origin of coalbed gases in southeastern Illinois Basin by compound-specific carbon and hydrogen stable isotope ratios

    USGS Publications Warehouse

    Strapoc, D.; Mastalerz, Maria; Eble, C.; Schimmelmann, A.

    2007-01-01

    Coalbed gases and waters from exploratory and production gas wells in the southeastern Illinois Basin were sampled to assess geochemically the origin of coalbed gases, with an emphasis on the Springfield and Seelyville Coal Members that are commercially targeted for coalbed methane production in Indiana. On-line analyses of hydrocarbon gases methane to butanes (C1, C2, C3, n-C4, i-C4) and CO2 yielded gas concentrations, plus ??D and ??13C values. The low thermal maturity of Indiana coals with vitrinite reflectance R0 ??? 0.6% is in agreement with an overwhelmingly biogenic isotopic signature of coalbed gases containing ???96% methane generated via bacterial CO2-reduction. In contrast, thermogenic gas was generated in the stratigraphically equivalent coal beds in western Kentucky's Rough Creek Graben zone where higher maturities of up to R0 ??? 0.8% were reached owing to tectonic and hydrothermal activity. No secondary biogenic methane was observed in more mature western Kentucky coal beds where greater burial depth limits the recharge of meteoric water. Biogenic and thermogenic coalbed gases represent two end-members that are compositionally and isotopically distinct. Microbial biodegradation of thermogenic C2+ hydrocarbon gases in Indiana coal beds preferentially targets C3 and introduces isotope fractionation whereby remaining C3 is enriched in deuterium and 13C.

  12. Assessment of environmental health and safety issues associated with the commercialization of unconventional gas recovery: methane from coal seams

    SciTech Connect

    Ethridge, L.J.; Cowan, C.E.; Riedel, E.F.

    1980-07-01

    Potential public health and safety problems and the potential environmental impacts from the recovery of gas from coalbeds are identified and examined. The technology of methane recovery is described and economic and legal barriers to production are discussed. (ACR)

  13. Fermentation Enhancement of Methanogenic Archaea Consortia from an Illinois Basin Coalbed via DOL Emulsion Nutrition

    PubMed Central

    Xiao, Dong; Peng, Su-Ping; Wang, En-Yuan

    2015-01-01

    Microbially enhanced coalbed methane technology must be used to increase the methane content in mining and generate secondary biogenic gas. In this technology, the metabolic processes of methanogenic consortia are the basis for the production of biomethane from some of the organic compounds in coal. Thus, culture nutrition plays an important role in remediating the nutritional deficiency of a coal seam. To enhance the methane production rates for microorganism consortia, different types of nutrition solutions were examined in this study. Emulsion nutrition solutions containing a novel nutritional supplement, called dystrophy optional modification latex, increased the methane yield for methanogenic consortia. This new nutritional supplement can help methanogenic consortia form an enhanced anaerobic environment, optimize the microbial balance in the consortia, and improve the methane biosynthesis rate. PMID:25884952

  14. Results of coalbed-methane drilling, Mylan Park, Monongalia County, West Virginia: Chapter G.3 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ruppert, Leslie F.; Fedorko, Nick; Warwick, Peter D.; Grady, William C.; Britton, James Q.; Schuller, William A.; Crangle, Robert D.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    High-pressure carbon-dioxide adsorption isotherms were measured on composite coal samples of the Upper Kittanning coal bed and the Middle Kittanning and Clarion coal zones. Assuming that the reservoir pressure in the Mylan Park coals is equivalent to the normal hydrostatic pressure, the estimated maximum carbon-dioxide adsorption pressures range from a low of about 300 pounds per square inch (lb/in2 ) in coals from the Clarion coal zone to 500 lb/in2 for coals from the Upper Kittanning coal bed. The estimated maximum methane adsorption isotherms show that the coals from the Upper Kittanning coal bed and the Middle Kittanning coal zone are undersaturated in methane, but coals from the Clarion coal zone are close to saturation.

  15. Patterns of Endemism and Habitat Selection in Coalbed Microbial Communities

    PubMed Central

    Lawson, Christopher E.; Strachan, Cameron R.; Williams, Dominique D.; Koziel, Susan; Hallam, Steven J.

    2015-01-01

    Microbially produced methane, a versatile, cleaner-burning alternative energy resource to fossil fuels, is sourced from a variety of natural and engineered ecosystems, including marine sediments, anaerobic digesters, shales, and coalbeds. There is a prevailing interest in developing environmental biotechnologies to enhance methane production. Here, we use small-subunit rRNA gene sequencing and metagenomics to better describe the interplay between coalbed methane (CBM) well conditions and microbial communities in the Alberta Basin. Our results show that CBM microbial community structures display patterns of endemism and habitat selection across the Alberta Basin, consistent with observations from other geographical locations. While some phylum-level taxonomic patterns were observed, relative abundances of specific taxonomic groups were localized to discrete wells, likely shaped by local environmental conditions, such as coal rank and depth-dependent physicochemical conditions. To better resolve functional potential within the CBM milieu, a metagenome from a deep volatile-bituminous coal sample was generated. This sample was dominated by Rhodobacteraceae genotypes, resolving a near-complete population genome bin related to Celeribacter sp. that encoded metabolic pathways for the degradation of a wide range of aromatic compounds and the production of methanogenic substrates via acidogenic fermentation. Genomic comparisons between the Celeribacter sp. population genome and related organisms isolated from different environments reflected habitat-specific selection pressures that included nitrogen availability and the ability to utilize diverse carbon substrates. Taken together, our observations reveal that both endemism and metabolic specialization should be considered in the development of biostimulation strategies for nonproductive wells or for those with declining productivity. PMID:26341214

  16. Patterns of Endemism and Habitat Selection in Coalbed Microbial Communities.

    PubMed

    Lawson, Christopher E; Strachan, Cameron R; Williams, Dominique D; Koziel, Susan; Hallam, Steven J; Budwill, Karen

    2015-11-01

    Microbially produced methane, a versatile, cleaner-burning alternative energy resource to fossil fuels, is sourced from a variety of natural and engineered ecosystems, including marine sediments, anaerobic digesters, shales, and coalbeds. There is a prevailing interest in developing environmental biotechnologies to enhance methane production. Here, we use small-subunit rRNA gene sequencing and metagenomics to better describe the interplay between coalbed methane (CBM) well conditions and microbial communities in the Alberta Basin. Our results show that CBM microbial community structures display patterns of endemism and habitat selection across the Alberta Basin, consistent with observations from other geographical locations. While some phylum-level taxonomic patterns were observed, relative abundances of specific taxonomic groups were localized to discrete wells, likely shaped by local environmental conditions, such as coal rank and depth-dependent physicochemical conditions. To better resolve functional potential within the CBM milieu, a metagenome from a deep volatile-bituminous coal sample was generated. This sample was dominated by Rhodobacteraceae genotypes, resolving a near-complete population genome bin related to Celeribacter sp. that encoded metabolic pathways for the degradation of a wide range of aromatic compounds and the production of methanogenic substrates via acidogenic fermentation. Genomic comparisons between the Celeribacter sp. population genome and related organisms isolated from different environments reflected habitat-specific selection pressures that included nitrogen availability and the ability to utilize diverse carbon substrates. Taken together, our observations reveal that both endemism and metabolic specialization should be considered in the development of biostimulation strategies for nonproductive wells or for those with declining productivity. PMID:26341214

  17. Organic petrology and coalbed gas content, Wilcox Group (Paleocene-Eocene), northern Louisiana

    USGS Publications Warehouse

    Hackley, P.C.; Warwick, P.D.; Breland, F.C.

    2007-01-01

    Wilcox Group (Paleocene-Eocene) coal and carbonaceous shale samples collected from four coalbed methane test wells in northern Louisiana were characterized through an integrated analytical program. Organic petrographic analyses, gas desorption and adsorption isotherm measurements, and proximate-ultimate analyses were conducted to provide insight into conditions of peat deposition and the relationships between coal composition, rank, and coalbed gas storage characteristics. The results of petrographic analyses indicate that woody precursor materials were more abundant in stratigraphically higher coal zones in one of the CBM wells, consistent with progradation of a deltaic depositional system (Holly Springs delta complex) into the Gulf of Mexico during the Paleocene-Eocene. Comparison of petrographic analyses with gas desorption measurements suggests that there is not a direct relationship between coal type (sensu maceral composition) and coalbed gas storage. Moisture, as a function of coal rank (lignite-subbituminous A), exhibits an inverse relationship with measured gas content. This result may be due to higher moisture content competing for adsorption space with coalbed gas in shallower, lower rank samples. Shallower ( 600??m) coal samples containing less moisture range from under- to oversaturated with respect to their CH4 adsorption capacity.

  18. Distribution and geochemical characterization of coalbed gases at excavation fields at natural analogue site area Velenje Basin, Slovenia

    NASA Astrophysics Data System (ADS)

    Kanduč, Tjaša; Žigon, Stojan; Grassa, Fausto; Sedlar, Jerneja; Zadnik, Ivo; Zavšek, Simon

    2016-04-01

    Unconventional gas resources, including coal bed methane and shale gas, are a growing part of the global energy mix, which has changed the economic and strategic picture for gas consuming and producing countries, including the USA, China and Australia that, together are responsible for around half the currently recoverable unconventional gas resources. However, CBM production was often hindered by low permeability and mineralization in cleats and fractures, necessitating the development of cost effective horizontal drilling and completion techniques. Geochemical and isotopic monitoring of coalbed gases at excavation fields in Velenje Basin started in year 2000, with the aim to obtain better insights into the origin of coalbed gases. Results from active excavation fields in the mining areas Pesje and Preloge in the year period 2014-2015 are presented in this study. Composition and isotopic composition of coalbed gases were determined with mass - spectrometric methods. The chemical (methane, carbon dioxide, nitrogen) and isotopic composition of carbon in methane and carbon dioxide in the Velenje Basin vary and depend on the composition of the source of coalbed gas before excavation, advancement of the working face, depth of the longwall face, pre-mining activity and newly mined activity. The basic gas components determined in excavation fields are carbon dioxide and methane. Knowledge of the stable isotope geochemistry of coal bed and shale gas and the related production water is essential to determine not only gas origins but also the dominant methanogenic pathway in the case of microbial gas. Concentrations of methane at active excavation fields are changing from 1.8 to 63.9 %, concentrations of carbon dioxide are changing from 36.1 to 98.2% and CDMI (Carbon Dioxide Methane Index) index from 0.2 to 100 %. Isotopic composition of carbon dioxide is changing from -11.0 to -1.9‰ , isotopic composition of methane from -71.8 to -43.3‰ , isotopic composition of

  19. Assessment of undiscovered carboniferous coal-bed gas resources of the Appalachian Basin and Black Warrior Basin Provinces, 2002

    SciTech Connect

    Milici, R.C.; Hatch, J.R.

    2004-09-15

    Coalbed methane (CBM) occurs in coal beds of Mississippian and Pennsylvanian (Carboniferous) age in the Appalachian basin, which extends almost continuously from New York to Alabama. In general, the basin includes three structural subbasins: the Dunkard basin in Pennsylvania, Ohio, and northern West Virginia; the Pocahontas basin in southern West Virginia, eastern Kentucky, and southwestern Virginia; and the Black Warrior basin in Alabama and Mississippi. For assessment purposes, the Appalachian basin was divided into two assessment provinces: the Appalachian Basin Province from New York to Alabama, and the Black Warrior Basin Province in Alabama and Mississippi. By far, most of the coalbed methane produced in the entire Appalachian basin has come from the Black Warrior Basin Province. 8 refs., 1 fig., 1 tab.

  20. Geochemical analysis of atlantic rim water, carbon county, wyoming: New applications for characterizing coalbed natural gas reservoirs

    USGS Publications Warehouse

    McLaughlin, J.F.; Frost, C.D.; Sharma, Shruti

    2011-01-01

    Coalbed natural gas (CBNG) production typically requires the extraction of large volumes of water from target formations, thereby influencing any associated reservoir systems. We describe isotopic tracers that provide immediate data on the presence or absence of biogenic natural gas and the identify methane-containing reservoirs are hydrologically confined. Isotopes of dissolved inorganic carbon and strontium, along with water quality data, were used to characterize the CBNG reservoirs and hydrogeologic systems of Wyoming's Atlantic Rim. Water was analyzed from a stream, springs, and CBNG wells. Strontium isotopic composition and major ion geochemistry identify two groups of surface water samples. Muddy Creek and Mesaverde Group spring samples are Ca-Mg-S04-type water with higher 87Sr/86Sr, reflecting relatively young groundwater recharged from precipitation in the Sierra Madre. Groundwaters emitted from the Lewis Shale springs are Na-HCO3-type waters with lower 87Sr/86Sr, reflecting sulfate reduction and more extensive water-rock interaction. To distinguish coalbed waters, methanogenically enriched ??13CDIC wasused from other natural waters. Enriched ??13CDIC, between -3.6 and +13.3???, identified spring water that likely originates from Mesaverde coalbed reservoirs. Strongly positive ??13CDIC, between +12.6 and +22.8???, identified those coalbed reservoirs that are confined, whereas lower ??13CDIC, between +0.0 and +9.9???, identified wells within unconfined reservoir systems. Copyright ?? 2011. The American Association of Petroleum Geologists. All rights reserved.

  1. Methanogenic pathways of coal-bed gas in the Powder River Basin, United States: The geologic factor

    USGS Publications Warehouse

    Flores, R.M.; Rice, C.A.; Stricker, G.D.; Warden, A.; Ellis, M.S.

    2008-01-01

    Coal-bed gas of the Tertiary Fort Union and Wasatch Formations in the Powder River Basin in Wyoming and Montana, U.S. was interpreted as microbial in origin by previous studies based on limited data on the gas and water composition and isotopes associated with the coal beds. To fully evaluate the microbial origin of the gas and mechanisms of methane generation, additional data for 165 gas and water samples from 7 different coal-bed methane-bearing coal-bed reservoirs were collected basinwide and correlated to the coal geology and stratigraphy. The C1/(C2 + C3) ratio and vitrinite reflectance of coal and organic shale permitted differentiation between microbial gas and transitional thermogenic gas in the central part of the basin. Analyses of methane ??13C and ??D, carbon dioxide ??13C, and water ??D values indicate gas was generated primarily from microbial CO2 reduction, but with significant gas generated by microbial methyl-type fermentation (aceticlastic) in some areas of the basin. Microbial CO2 reduction occurs basinwide, but is generally dominant in Paleocene Fort Union Formation coals in the central part of the basin, whereas microbial methyl-type fermentation is common along the northwest and east margins. Isotopically light methane ??13C is distributed along the basin margins where ??D is also depleted, indicating that both CO2-reduction and methyl-type fermentation pathways played major roles in gas generation, but gas from the latter pathway overprinted gas from the former pathway. More specifically, along the northwest basin margin gas generation by methyl-type fermentation may have been stimulated by late-stage infiltration of groundwater recharge from clinker areas, which flowed through highly fractured and faulted coal aquifers. Also, groundwater recharge controlled a change in gas composition in the shallow Eocene Wasatch Formation with the increase of nitrogen and decrease of methane composition of the coal-bed gas. Other geologic factors, such as

  2. Microbial Methanogenesis In Laboratory Incubations Of Coal: Implications For A Sustainable Energy Resource In Subsurface Coalbeds

    NASA Astrophysics Data System (ADS)

    Harris, S. H.; Barker, C. E.; Smith, R. L.

    2005-12-01

    Methane desorbed from subsurface coalseams contributes about 8% of the total natural gas produced in the US. This value is expected to increase over the next several years as a growing proportion of energy demands are supplied from unconventional reservoirs. Isotopic analyses of gas samples from several geographically separate coalbeds indicates a substantial proportion of the sorbed methane is biogenic in origin. Furthermore, previous studies have shown the ability of microbial consortia to degrade coal in aerobic laboratory incubations. These findings suggests the stimulation of microbial methane production in subsurface coals may provide a sustainable source of domestic energy. To address this prospect, we assessed the ability of indigenous microbial populations to produce methane in coal maintained under anaerobic conditions in the laboratory and investigated factors that influenced the rate and extent of the process. Several freshly collected coals of different rank were examined for their ability to support methanogenesis in mineral medium alone or amended with different nutrients such as hydrogen (4 kPa), formate (20 mM), or acetate (25mM). Microbial methane production was distinguished from abiotic desorption by subtracting methane generated in replicate incubations that contained bromoethanesulfonic acid (5 mM), an inhibitor of methanogenesis. The extent and rate of methane production varied among the different coals. A relatively shallow (400 m), immature coal exhibited a rate of 700 nmole CH4*day-1*g coal-1, a value comparable to previous observations of contaminated sediments. Methane production was negligible in a deeper, relatively mature (650 m) coal obtained from the same borehole although the same material exhibited a rate of about 80 nmole CH4*day-1*g coal-1 after a formate amendment. In contrast, hydrogen proved to be ineffective as a methanogenic substrate, although this electron donor was rapidly consumed in coal incubations. A filter

  3. Stable and radiogenic isotopic analysis of aquifer systems, Atlantic Rim, Carbon County, Wyoming: Implications for production of coalbed natural gas

    NASA Astrophysics Data System (ADS)

    McLaughlin, J. Fred

    Coalbed natural gas (CBNG) production requires the extraction of considerable volumes of water from target formations. This process can dynamically alter local aquifers and affect the larger hydrologic systems of a producing area. An analytical method that provides immediate, cost-effective quantitative information on both resource (methane) and habitat (coalbed aquifer) would help to optimize gas production. This study used a combination of field measurements, water chemistry analysis, and isotopic analysis, both stable (delta13C DIC, deltaO, deltaD) and radiometric (87Sr/ 86Sr), to analyze and characterize the CBNG aquifers and hydrogeologic systems of Wyoming's Atlantic Rim. Waters were sampled and analyzed from streams, springs, and CBNG wells across the Atlantic Rim. Samples were first grouped on the basis of geologic location, and then additionally defined by isotopic and water chemistry analysis into Mesaverde Group springs, Lewis Shale springs, Steele Shale springs, Sand Hill springs, enriched delta 13CDIC springs, methane springs, and subsurface samples (monitoring and CBNG wells). Two distinct water chemistry types are evident in Atlantic Rim samples, Ca-Mg-SO4-type and Na-HCO3-type waters. Atlantic Rim samples also had distinct radiogenic isotopic signatures. Stream water sourced from the Sierra Madre and waters associated with the Mesaverde Group have the highest 87Sr/86Sr ratios, whereas spring samples from the Lewis Shale have the lowest 87Sr/ 86Sr. delta13CDIC, which is enriched by bacterial methanogenesis, was used to identify coalbed waters from other natural waters. Positive delta13CDIC identified spring waters that originated from Mesaverde coalbed aquifers, including methane springs. Strongly positive delta13CDIC of Atlantic Rim CBNG samples identified those coalbed aquifers that are hydraulically isolated, whereas lower delta13CDIC identified wells within open aquifer systems and wells with inefficient casing. This study demonstrated that delta

  4. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-12-26

    The authors' long term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The major objectives of the project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized in three broad categories outlining experimentation, model development, and coal characterization.

  5. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-06-15

    During the present reporting period, six complementary tasks involving experimentation, model development, and coal characterization were undertaken to meet our project objectives: (1) A second adsorption apparatus, utilizing equipment donated by BP Amoco, was assembled. Having confirmed the reliability of this additional experimental apparatus and procedures, adsorption isotherms for CO{sub 2}, methane, ethane, and nitrogen on wet Fruitland coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 3%. The addition of this new facility has allowed us to essentially double our rate of data production. (2) Adsorption isotherms for pure CO{sub 2}, methane, and nitrogen on wet Illinois-6 coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia) on our first apparatus. The activated carbon measurements showed good agreement with literature data and with measurements obtained on our second apparatus. The expected uncertainty of the data is about 3%. The Illinois-6 adsorption measurements are a new addition to the existing database. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on DESC-8 coal. (3) Adsorption from binary mixtures of methane, nitrogen and CO{sub 2} at a series of compositions was also measured on the wet Fruitland coal at 319.3 K (115 F), using our first apparatus. The nominal compositions of these mixtures are 20%/80%, 40%/60%, 60%/40%, and 80%/20%. The experiments were conducted at pressures from 100 psia to 1800 psia. The expected uncertainty for these binary mixture data varies from 2 to 9%. (4) A study was completed to address the previously-reported rise in the CO{sub 2} absolute adsorption on wet Fruitland coal at 115 F and pressures exceeding 1200 psia. Our additional adsorption measurements on

  6. Integrating geophysics and geochemistry to evaluate coalbed natural gas produced water disposal, Powder River Basin, Wyoming

    NASA Astrophysics Data System (ADS)

    Lipinski, Brian Andrew

    Production of methane from thick, extensive coalbeds in the Powder River Basin of Wyoming has created water management issues. More than 4.1 billion barrels of water have been produced with coalbed natural gas (CBNG) since 1997. Infiltration impoundments, which are the principal method used to dispose CBNG water, contribute to the recharge of underlying aquifers. Airborne electromagnetic surveys of an alluvial aquifer that has been receiving CBNG water effluent through infiltration impoundments since 2001 reveal produced water plumes within these aquifers and also provide insight into geomorphologic controls on resultant salinity levels. Geochemical data from the same aquifer reveal that CBNG water enriched in sodium and bicarbonate infiltrates and mixes with sodium-calcium-sulfate type alluvial groundwater, which subsequently may have migrated into the Powder River. The highly sodic produced water undergoes cation exchange reactions with native alluvial sediments as it infiltrates, exchanging sodium from solution for calcium and magnesium on montmorillonite clays. The reaction may ultimately reduce sediment permeability by clay dispersion. Strontium isotope data from CBNG wells discharging water into these impoundments indicate that the Anderson coalbed of the Fort Union Formation is dewatered due to production. Geophysical methods provide a broad-scale tool to monitor CBNG water disposal especially in areas where field based investigations are logistically prohibitive, but geochemical data are needed to reveal subsurface processes undetectable by geophysical techniques. The results of this research show that: (1) CBNG impoundments should not be located near streams because they can alter the surrounding hydraulic potential field forcing saline alluvial groundwater and eventually CBNG water into the stream, (2) point bars are poor impoundment locations because they are essentially in direct hydraulic communication with the associated stream and because plants

  7. Toxicity of Sodium Bicarbonate to Fish from Coal-Bed Natural Gas Production in the Tongue and Powder River Drainages, Montana and Wyoming

    USGS Publications Warehouse

    ,

    2006-01-01

    This study evaluates the sensitivity of aquatic life to sodium bicarbonate (NaHCO3), a major constituent of coal-bed natural gas-produced water. Excessive amounts of sodium bicarbonate in the wastewater from coal-bed methane natural gas production released to freshwater streams and rivers may adversely affect the ability of fish to regulate their ion uptake. The collaborative study focuses on the acute and chronic toxicity of sodium bicarbonate on select fish species in the Tongue and Powder River drainages in southeastern Montana and northeastern Wyoming. Sodium bicarbonate is not naturally present in appreciable concentrations within the surface waters of the Tongue and Powder River drainages; however, the coal-bed natural gas wastewater can reach levels over 1,000 milligrams per liter. Large concentrations have been shown to be acutely toxic to native fish (Mount and others, 1997). In 2003, with funding and guidance provided by the U.S. Environmental Protection Agency, the Montana Fish, Wildlife, and Parks and the U.S. Geological Survey initiated a collaborative study on the potential effects of coal-bed natural gas wastewater on aquatic life. A major goal of the study is to provide information to the State of Montana Water Quality Program needed to develop an aquatic life standard for sodium bicarbonate. The standard would allow the State, if necessary, to establish targets for sodium bicarbonate load reductions.

  8. Cultivation of methanogenic community from 2-km deep subseafloor coalbeds using a continuous-flow bioreactor

    NASA Astrophysics Data System (ADS)

    Imachi, H.; Tasumi, E.; Morono, Y.; Ito, M.; Takai, K.; Inagaki, F.

    2013-12-01

    Deep subseafloor environments associated with hydrocarbon reservoirs have been least explored by previous scientific drilling and hence the nature of deep subseafloor life and its ecological roles in the carbon cycle remain largely unknown. In this study, we performed cultivation of subseafloor methanogenic communities using a continuous-flow bioreactor with polyurethane sponges, called down-flow hanging sponge (DHS) reactor. The sample used for the reactor cultivation was obtained from 2 km-deep coalbeds off the Shimokita Peninsula of Japan, the northwestern Pacific, during the Integrated Ocean Drilling Program (IODP) Expedition 337 using a riser drilling technology of the drilling vessel Chikyu. The coalbed samples were incubated anaerobically in the DHS reactor at the in-situ temperature of 40°C. Synthetic seawater supplemented with a tiny amount of yeast extract, acetate, propionate and butyrate was provided into the DHS reactor. After 34 days of the bioreactor operation, a small production of methane was observed. The methane concentration was gradually increased and the stable carbon isotopic composition of methane was consistency 13C-depleted during the bioreactor operation, indicating the occurrence of microbial methanogenesis. Microscopic observation showed that the enrichment culture contained a variety of microorganisms, including methanogen-like rod-shaped cells with F420 auto-fluorescence. Interestingly, many spore-like particles were observed in the bioreactor enrichment. Phylogenetic analysis of 16S rRNA genes showed the growth of phylogenetically diverse bacteria and archaea in the DHS reactor. Predominant archaeal components were closely related to hydrogenotrophic methanogens within the genus Methanobacterium. Some predominant bacteria were related to the spore-formers within the class Clostridia, which are overall in good agreement with microscopic observations. By analyzing ion images using a nano-scale secondary ion mass spectrometry (Nano

  9. Analysis of hydrocarbons generated in coalbeds

    NASA Astrophysics Data System (ADS)

    Butala, Steven John M.

    This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

  10. Fall may be imminent for Kansas Cherokee basin coalbed gas output

    USGS Publications Warehouse

    David, Newell K.

    2010-01-01

    Natural gas production in the Kansas portion of the Cherokee basin, Southeastern Kansas, for 2008 was 49.1 bcf. The great majority of Cherokee basin gas production is now coal-bed methane (CBM). The major producers are Quest Energy LLC, Dart Cherokee Basin Operating Co. LLC, and Layne Energy Operating LLC. Most CBM in Southeastern Kansas is from Middle and Upper Pennsylvanian high-volatile B and A rank bituminous coals at 800 to 1,200 ft depth. Rates of decline for the CBM wells generally decrease the longer a well produces. A gentler collective decline of 13.8% is calculated by averaging the number of new producing wells in a given year with that of the previous year. By the calculations using the gentler overall 13.8% decline rate, if more than 918 successful CBM wells are drilled in 2009, then gas production will increase from 2008 to 2009.

  11. Competitive Adsorption of Carbon Dioxide/Methane in Coal: First-Principles Quantum Mechanical Investigations

    NASA Astrophysics Data System (ADS)

    Liu, Yingdi; Wang, Sanwu

    Sequestration of CO2 into geological formations has been suggested to mitigate the effect of the increasing of the atmospheric CO2 concentration on global warming. Coalbeds are investigated as one of the attractive storage sites since the cost of CO2 sequestration can be offset by the enhanced coalbed methane (ECBM) recovery. Extensive experimental studies have been performed for the competitive adsorption of CO2/CH4 into coalbeds. However, the atomic-level understanding for the interaction between the adsorbate (CO2/CH4) and the adsorbent (coal) has not been fully explored. We report first-principles density-functional calculations for the competitive adsorption between CO2/CH4 in the coal network. In particular, we report results of atomic structures, bonding characteristics, energetics, as well as electronic structures of the CO2/CH4-coal systems. This research used the supercomputer resources at NERSC, of XSEDE, at TACC, and at the Tandy Supercomputing Center.

  12. Stored CO2 and Methane Leakage Risk Assessment and Monitoring Tool Development: CO2 Capture Project Phase 2 (CCP2)

    SciTech Connect

    Dan Kieki

    2008-09-30

    The primary project goal is to develop and test tools for optimization of ECBM recovery and geologic storage of CO{sub 2} in coalbeds, in addition to tools for monitoring CO{sub 2} sequestration in coalbeds to support risk assessment. Three critical topics identified are (1) the integrity of coal bed methane geologic and engineered systems, (2) the optimization of the coal bed storage process, and (3) reliable monitoring and verification systems appropriate to the special conditions of CO{sub 2} storage and flow in coals.

  13. Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

    SciTech Connect

    James Bauder

    2008-09-30

    U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial waste product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments when

  14. Methane conversion

    SciTech Connect

    Jones, C.A.; Leonard, J.J.; Sofranko, J.A.

    1984-04-17

    Another version of Arco's process for reforming methane or natural gas into a synthesis gas uses bismuth oxide as the reforming agent; it also requires no nickel or noble metal catalyst. The methane-containing gas contacts bismuth oxide at temperatures of 900/sup 0/-1560/sup 0/F. The oxide is reduced by methane and easily regenerated with an oxygen-containing gas. The oxide Bi/sub 2/O/sub 3/ is a particularly effective synthesizing agent.

  15. Financing coal mine, methane recovery and utilization projects

    SciTech Connect

    2006-07-01

    The article describes types and sources of funding that may be available to project developers and investors that are interested in pursuing coal mine methane (CMM) project opportunities particularly in developing countries or economies in transition. It briefly summarizes prefeasibility and feasibility studies and technology demonstrations. It provides a guide to key parties involved in project financing (equity, debt or carbon financing) as well as project risk reduction support. This article provides an update to the information contained in two previous guides - Catalogue of Coal Mine Methane Project Finance Sources (2002) and A Guide to Financing Coalbed Methane Projects (1997) - both available on the CMOP web site http://www.epa.gov/cmop/resources/reports/finance.html.

  16. Formation and retention of methane in coal

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  17. Sinking methane.

    PubMed

    Reay, David S

    2003-02-01

    Concentrations of the powerful greenhouse gas, methane, in our atmosphere have doubled since the beginning of the industrial age. Reducing these levels is a vital part of global efforts to combat global warming. Could we make use of the Earth's own methane sinks?

  18. Methane Gas Concentration in Soils and Ground Water, Carbon and Emery Counties, Utah, 1995-2003

    USGS Publications Warehouse

    Stolp, B.J.; Burr, A.L.; Johnson, K.K.

    2006-01-01

    The release of methane gas from coal beds creates the potential for it to move into near-surface environments through natural and human-made pathways. To help ensure the safety of communities and determine the potential effects of development of coal-bed resources, methane gas concentrations in soils and ground water in Carbon and Emery Counties, Utah, were monitored from 1995 to 2003. A total of 420 samples were collected, which contained an average methane concentration of 2,740 parts per million by volume (ppmv) and a median concentration of less than 10 ppmv. On the basis of spatial and temporal methane concentration data collected during the monitoring period, there does not appear to be an obvious, widespread, or consistent migration of methane gas to the near-surface environment.

  19. Monitoring for Methane Gas in Carbon and Emery Counties, Utah, 1995-2003

    USGS Publications Warehouse

    Burr, Andrew L.; Stolp, Bernard J.; Johnson, Kevin K.; Hunt, Gilbert L.

    2006-01-01

    The release of methane gas from coal beds creates the potential for it to move into near-surface environments through natural and human-made pathways. To help ensure the safety of communities and determine the potential effects of development of coal-bed resources, methane gas concentrations in soils and ground water in Carbon and Emery Counties, Utah, were monitored from 1995 to 2003. A total of 420 samples were collected, which contained an average methane concentration of 2,740 parts per million by volume (ppmv) and a median concentration of less than 10 ppmv. On the basis of spatial and temporal methane concentration data collected during the monitoring period, there does not appear to be an obvious, widespread, or consistent migration of methane gas to the near-surface environment.

  20. An anomalous subdiffusion model with fractional derivatives for methane desorption in heterogeneous coal matrix

    NASA Astrophysics Data System (ADS)

    Kang, Jianhong; Zhou, Fubao; Ye, Gaobang; Liu, Yingke

    2015-12-01

    Methane desorption in coal matrix is one of the fundamental gas transport processes during coalbed methane extraction, the mechanism of which is commonly described by Fickian diffusion theory. Here, an anomalous subdiffusion model with fractional derivatives is developed to explore the methane desorption in coal matrix with a highly heterogeneous pore structure. Numerical simulations reproduce the volume fraction of gas desorbed over the entire timescale of experimental desorption. It is suggested that the diffusion of methane in heterogeneous coal matrix may obey the anomalous time and space subdiffusion, rather than Fickian second law. The physical reason is perhaps due to the basic topological complexity inherent to porous coal matrix and the strong adsorption effect of coal on methane molecules.

  1. Assessment of CO2 Sequestration and ECBM Potential of U.S. Coalbeds

    SciTech Connect

    Scott R. Reeves

    2003-03-31

    In October, 2000, the U.S. Department of Energy, through contractor Advanced Resources International, launched a multi-year government-industry R&D collaboration called the Coal-Seq project. The Coal-Seq project is investigating the feasibility of CO{sub 2} sequestration in deep, unmineable coalseams, by performing detailed reservoir studies of two enhanced coalbed methane recovery (ECBM) field projects in the San Juan basin. The two sites are the Allison Unit, operated by Burlington Resources, and into which CO{sub 2} is being injected, and the Tiffany Unit, operating by BP America, into which N{sub 2} is being injected (the interest in understanding the N{sub 2}-ECBM process has important implications for CO{sub 2} sequestration via flue-gas injection). The purposes of the field studies are to understand the reservoir mechanisms of CO{sub 2} and N{sub 2} injection into coalseams, demonstrate the practical effectiveness of the ECBM and sequestration processes, an engineering capability to simulate them, and to evaluate sequestration economics. In support of these efforts, laboratory and theoretical studies are also being performed to understand and model multi-component isotherm behavior, and coal permeability changes due to swelling with CO{sub 2} injection. This report describes the results of an important component of the overall project, applying the findings from the San Juan Basin to a national scale to develop a preliminary assessment of the CO{sub 2} sequestration and ECBM recovery potential of U.S. coalbeds. Importantly, this assessment improves upon previous investigations by (1) including a more comprehensive list of U.S. coal basins, (2) adopting technical rationale for setting upper-bound limits on the results, and (3) incorporating new information on CO{sub 2}/CH{sub 4} replacement ratios as a function of coal rank. Based on the results of the assessment, the following conclusions have been drawn: (1) The CO{sub 2} sequestration capacity of U

  2. Breaking methane

    PubMed Central

    Rosenzweig, Amy C.

    2015-01-01

    The most powerful oxidant found in nature is compound Q, an enzymatic intermediate that oxidizes methane. New spectroscopic data have resolved the long-running controversy about Q’s chemical structure. PMID:25607367

  3. Harnessing methane

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The total methane resource in hydrates—ice-like substances found in deep ocean sediments and Arctic permafrost—exceeds the energy content of all other fossil fuel resources,such as coal, oil, and conventional gas, according to the U.S. Geological Survey (USGS).The Methane Hydrate Research and Development Act, signed into law by U.S. President Bill Clinton on May 3, establishes a new federal commitment to developing methane hydrates, which has been touted as a potentially clean energy source that could make the U.S. less dependent on foreign sources of energy. The bill authorizes $47.5 million over five years for the Department of Energy to establish a federal methane hydrate research and development program.

  4. Integrated process for coalbed brine disposal

    SciTech Connect

    Brandt, H. |; Bourcier, W.L.; Jackson, K.J.

    1994-03-01

    A brine disposal process is described that converts the brine stream of a coalbed gas producing site into clean water for agricultural use, combustion products and water vapor that can be released into the atmosphere and dry solids that can be recycled for industrial consumption. The process uses a reverse osmosis unit, a submerged combustion evaporator and a pulse combustion dryer. Pretreatment of the brine feedstream is necessary to prevent fouling of the membranes of the reverse osmosis unit and to separate from the brine stream hazardous metal and other constituents that may make the permeate from the reverse osmosis unit unsuitable for agricultural or other use. A chemical modeling code is used to calculate the saturation states of solids that may precipitate and foul the reverse osmosis membranes. Sodium carbonate is added to the brine to precipitate carbonates of Ba, Ca, Mg and Sr prior to filtration, acidification, and passage into the reverse osmosis unit. Optimization of the process in terms of types and amounts of additives is possible with analysis using the modeling code. The minimum amounts of additives to prevent scaling are calculated. In a typical operation, a brine feedstream of 1,000 m{sup 3}/day (6,290 bpd) that may have a total dissolved salt concentration (TDS) of 7,000 ppm will be separated into a permeate stream of 750 m{sup 3}/day (4,718 bpd) with a TDS of 400 ppm and a concentrated brine stream of 250 m{sup 3}/day (1,573 bpd) with a TDS of 26,800 ppm. The submerged combustion evaporator will concentrate this latter stream to a concentration of 268,000 ppm and reduce the volume to 25 m{sup 3}/day (158 bpd). The pulse combustion dryer can dry the concentrated brine mixture to a low moisture salt. Energy costs to operate the reverse osmosis unit are primarily the pumping costs.

  5. An evaluation of pretreatment agents for the stimulation of secondary biogenic coalbed natural gas

    NASA Astrophysics Data System (ADS)

    Huang, Zaixing

    Coalbed methane is considered to be an underexploited source of clean energy and, with the realization of its biogenic nature, it has attracted increasing interest in recent decades. Most of the published studies on biogenic coal bed natural gas (CBNG) have focused either on biostimulation (the addition of nutrients to stimulate the native microbial populations) or bioaugmentation (the addition of both nutrients and non-native microbial consortia of microorganisms). Although these approaches have shown promise, they are predicated on the assumption that the coal seam is nutrient-limited or that the existing microbial communities are not optimized to convert coal to natural gas. The premise of this research is that the organic matter present within the coal matrix is, for the most part, environmentally inert and not readily available to the microorganisms living within the coal seam. The goal of this research has been to focus on treatments that will increase the solubility, and hence the bioavailability, of coal to the indigenous microbial community. Initially, treatment agents representing acids, bases and oxidants were selected to evaluate the potential for the in situ solubilization and depolymerization of subbituminous coal. The bioavailability of the coal-derived constituents was then evaluated aerobically using biometer assays and anaerobic bioassays. The experiments have shown that the acid (nitric acid) and base (sodium hydroxide) treatments are more efficient than the oxidants (potassium permanganate and catalyzed hydrogen peroxide) with respect to total organic carbon (TOC). The carbon contained in the solubilized/depolymerized product of nitric acid treatments accounted for approximately 14% of the carbon from the Powder River Basin (PRB) coal evaluated in the study; however, the biometer assays revealed that the bioavailability of the solubilized/depolymerized products was not directly correlated to the amount of dissolved organic carbon (TOC). The

  6. Coalbed gas play emerges in eastern Kansas basins

    USGS Publications Warehouse

    Newell, K.D.; Brady, L.L.; Lange, J.P.; Carr, T.R.

    2002-01-01

    Coalbed gas from Middle Pennsylvanian rocks in eastern Kansas is an emerging new energy play. Many of the critical geological parameters that will prove to be the major controls on the production fairways of this potential new resource have yet to be determined. Nevertheless, preliminary analyses indicate that recent leasing and exploration may translate into long-term production of new gas resources in what was hitherto considered a supermature petroleum province.

  7. Methane emissions measurements of natural gas components using a utility terrain vehicle and portable methane quantification system

    NASA Astrophysics Data System (ADS)

    Johnson, Derek; Heltzel, Robert

    2016-11-01

    Greenhouse Gas (GHG) emissions are a growing problem in the United States (US). Methane (CH4) is a potent GHG produced by several stages of the natural gas sector. Current scrutiny focuses on the natural gas boom associated with unconventional shale gas; however, focus should still be given to conventional wells and outdated equipment. In an attempt to quantify these emissions, researchers modified an off-road utility terrain vehicle (UTV) to include a Full Flow Sampling system (FFS) for methane quantification. GHG emissions were measured from non-producing and remote low throughput natural gas components in the Marcellus region. Site audits were conducted at eleven locations and leaks were identified and quantified at seven locations including at a low throughput conventional gas and oil well, two out-of-service gathering compressors, a conventional natural gas well, a coalbed methane well, and two conventional and operating gathering compressors. No leaks were detected at the four remaining sites, all of which were coal bed methane wells. The total methane emissions rate from all sources measured was 5.3 ± 0.23 kg/hr, at a minimum.

  8. Research and Development Concerning Coalbed Natural Gas

    SciTech Connect

    William Ruckelshaus

    2008-09-30

    The Powder River Basin in northeastern Wyoming is one of the most active areas of coalbed natural gas (CBNG) development in the western United States. This resource provides clean energy but raises environmental concerns. Primary among these is the disposal of water that is co-produced with the gas during depressurization of the coal seam. Beginning with a few producing wells in Wyoming's Powder River Basin (PRB) in 1987, CBNG well numbers in this area increased to over 13,600 in 2004, with projected growth to 20,900 producing wells in the PRB by 2010. CBNG development is continuing apace since 2004, and CBNG is now being produced or evaluated in four other Wyoming coal basins in addition to the PRB, with roughly 3500-4000 new CBNG wells permitted statewide each year since 2004. This is clearly a very valuable source of clean fuel for the nation, and for Wyoming the economic benefits are substantial. For instance, in 2003 alone the total value of Wyoming CBNG production was about $1.5 billion, with tax and royalty income of about $90 million to counties, $140 million to the state, and $27 million to the federal government. In Wyoming, cumulative CBNG water production from 1987 through December 2004 was just over 380,000 acre-feet (2.9 billion barrels), while producing almost 1.5 trillion cubic feet (tcf) of CBNG gas statewide. Annual Wyoming CBNG water production in 2003 was 74,457 acre-feet (577 million barrels). Total production of CBNG water across all Wyoming coal fields could total roughly 7 million acre-feet (55.5 billion barrels), if all of the recoverable CBNG in the projected reserves of 31.7 tcf were produced over the coming decades. Pumping water from coals to produce CBNG has been designated a beneficial water use by the Wyoming State Engineer's Office (SEO), though recently the SEO has limited this beneficial use designation by requiring a certain gas/water production ratio. In the eastern part of the PRB where CBNG water is generally of good quality

  9. Assessment of Coalbed Gas Resources in Cretaceous and Tertiary Rocks on the North Slope, Alaska, 2006

    USGS Publications Warehouse

    Roberts, Steve; Barker, Charles E.; Bird, Kenneth J.; Charpentier, Ronald R.; Cook, Troy; Houseknecht, David W.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2006-01-01

    The North Slope of Alaska is a vast area of land north of the Brooks Range, extending from the Chukchi Sea eastward to the Canadian border. This Arctic region is known to contain extensive coal deposits; hypothetical coal resource estimates indicate that nearly 4 trillion short tons of coal are in Cretaceous and Tertiary rocks. Because of the large volume of coal, other studies have indicated that this region might also have potential for significant coalbed gas resources. The present study represents the first detailed assessment of undiscovered coalbed gas resources beneath the North Slope by the USGS. The assessment is based on the total petroleum system (TPS) concept. Geologic elements within a TPS relate to hydrocarbon source rocks (maturity, hydrocarbon generation, migration), the characteristics of reservoir rocks, and trap and seal formation. In the case of coalbed gas, the coal beds serve as both source rock and reservoir. The Brookian Coalbed Gas Composite TPS includes coal-bearing rocks in Cretaceous and Tertiary strata underlying the North Slope and adjacent Alaska State waters. Assessment units (AUs) within the TPS (from oldest to youngest) include the Nanushuk Formation Coalbed Gas AU, the Prince Creek and Tuluvak Formations Coalbed Gas AU, and the Sagavanirktok Formation Coalbed Gas AU.

  10. Coalbed natural gas exploration, drilling activities, and geologic test results, 2007-2010

    USGS Publications Warehouse

    Clark, Arthur C.

    2014-01-01

    The U.S. Geological Survey, in partnership with the U.S. Bureau of Land Management, the North Slope Borough, and the Arctic Slope Regional Corporation conducted a four-year study designed to identify, define, and delineate a shallow coalbed natural gas (CBNG) resource with the potential to provide locally produced, affordable power to the community of Wainwright, Alaska. From 2007 through 2010, drilling and testing activities conducted at three sites in or near Wainwright, identified and evaluated an approximately 7.5-ft-thick, laterally continuous coalbed that contained significant quantities of CBNG. This coalbed, subsequently named the Wainwright coalbed, was penetrated at depths ranging from 1,167 ft to 1,300 ft below land surface. Core samples were collected from the Wainwright coalbed at all three drill locations and desorbed-gas measurements were taken from seventeen 1-ft-thick sections of the core. These measurements indicate that the Wainwright coalbed contains enough CBNG to serve as a long-term energy supply for the community. Although attempts to produce viable quantities of CBNG from the Wainwright coalbed proved unsuccessful, it seems likely that with proper well-field design and by utilizing currently available drilling and reservoir stimulation techniques, this CBNG resource could be developed as a long-term economically viable energy source for Wainwright.

  11. Formation and retention of methane in coal. Final report

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  12. Deep subsurface drip irrigation using coal-bed sodic water: Part I. Water and solute movement

    SciTech Connect

    Bern, Carleton R; Breit, George N; Healy, Richard W; Zupancic, John W; Hammack, Richard

    2013-02-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300–480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  13. Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

    USGS Publications Warehouse

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

    2013-01-01

    Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

  14. Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

    USGS Publications Warehouse

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.; Hammack, Richard

    2013-01-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300-480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  15. Coalbed methane adsorption and desorption characteristics related to coal particle size

    NASA Astrophysics Data System (ADS)

    Yan-Yan, Feng; Wen, Yang; Wei, Chu

    2016-06-01

    Effects of particle size on CH4 and CO2 adsorption and desorption characteristics of coals are investigated at 308 K and pressures up to 5.0 MPa. The gas adsorption and desorption isotherms of coals with particle sizes ranging from 250 μm to 840 μm are measured via the volumetric method, and the Langmuir model is used to analyse the experimental results. Coal particle size is found to have an obvious effect on the coal pore structure. With the decrease of coal particle size in the process of grinding, the pore accessibility of the coal, including the specific surface area and pore volume, increases. Hence, coal with smaller particle size has higher specific surface area and higher pore volume. The ability of adsorption was highly related to the pore structure of coal, and coal particle size has a significant influence on coal adsorption/desorption characteristics, including adsorption capacity and desorption hysteresis for CH4 and CO2, i.e., coal with a smaller particle size achieves higher adsorption capacity, while the sample with a larger particle size has lower adsorption capacity. Further, coal with larger particle size is also found to have relatively large desorption hysteresis. In addition, dynamic adsorption performances of the samples are carried out at 298 K and at pressures of 0.1 MPa and 0.5 MPa, respectively, and the results indicate that with the increase of particle size, the difference between CO2 and CH4 adsorption capacities of the samples decreases. Project supported by the National Basic Research Program of China (Grant No. 2011CB201202).

  16. Simulation of CO2 Sequestration and Enhanced Coalbed Methane Production in Multiple Appalachian Basin Coal Seams

    SciTech Connect

    Bromhal, G.S.; Siriwardane, H.J.; Gondle, R.K.

    2007-11-01

    A DOE-funded field injection of carbon dioxide is to be performed in an Appalachian Basin coal seam by CONSOL Energy and CNX Gas later this year. A preliminary analysis of the migration of CO2 within the Upper Freeport coal seam and the resulting ground movements has been performed on the basis of assumed material and geometric parameters. Preliminary results show that ground movements at the field site may be in a range that are measurable by tiltmeter technology.

  17. Multi-Seam Well Completion Technology: Implications for Powder River Basin Coalbed Methane Production

    SciTech Connect

    Office of Fossil Energy; National Energy Technology Laboratory

    2003-09-01

    The purpose of this study is to evaluate the potential benefits of applying multiseam [well] completion (MSC) technology to the massive stack of low-rank coals in the Powder River Basin. As part of this, the study objectives are: Estimate how much additional CBM resource would become accessible and technically recoverable--compared to the current practice of drilling one well to drain a single coal seam; Determine whether there are economic benefits associated with MSC technology utilization (assuming its widespread, successful application) and if so, quantify the gains; Briefly examine why past attempts by Powder River Basin CBM operators to use MSC technology have been relatively unsuccessful; Provide the underpinnings to a decision whether a MSC technology development and/or demonstration effort is warranted by DOE. To a great extent, this assessment builds on the previously published study (DOE, 2002), which contains many of the key references that underlie this analysis. It is available on the U.S. Department of Energy, National Energy technology Laboratory, Strategic Center for Natural Gas website (www.netl.doe.gov/scng). It is suggested that readers obtain a copy of the original study to complement the current report.

  18. Methane seeps along boundaries of arctic permafrost thaw and melting glaciers

    NASA Astrophysics Data System (ADS)

    Anthony, P.; Walter Anthony, K. M.; Grosse, G.; Chanton, J.

    2014-12-01

    Methane, a potent greenhouse gas, accumulates in subsurface hydrocarbon reservoirs. In the Arctic, impermeable icy permafrost and glacial overburden form a 'cryosphere cap' that traps gas leaking from these reservoirs, restricting flow to the atmosphere. We document the release of geologic methane to the atmosphere from abundant gas seeps concentrated along boundaries of permafrost thaw and receding glaciers in Alaska. Through aerial and ground surveys we mapped >150,000 seeps identified as bubbling-induced open holes in lake ice. Subcap methane seeps had anomalously high fluxes, 14C-depletion, and stable isotope values matching known coalbed and thermogenic methane accumulations in Alaska. Additionally, we observed younger subcap methane seeps in Greenland that were associated with ice-sheet retreat since the Little Ice Age. These correlations suggest that in a warming climate, continued disintegration of permafrost, glaciers, and parts of the polar ice sheets will relax pressure on subsurface seals and further open conduits, allowing a transient expulsion of geologic methane currently trapped by the cryosphere cap.

  19. Piezophilic Bacteria Isolated from Sediment of the Shimokita Coalbed, Japan

    NASA Astrophysics Data System (ADS)

    Fang, J.; Kato, C.; Hori, T.; Morono, Y.; Inagaki, F.

    2013-12-01

    The Earth is a cold planet as well as pressured planet, hosting both the surface biosphere and the deep biosphere. Pressure ranges over four-orders of magnitude in the surface biosphere and probably more in the deep biosphere. Pressure is an important thermodynamic property of the deep biosphere that affects microbial physiology and biochemistry. Bacteria that require high-pressure conditions for optimal growth are called piezophilic bacteria. Subseafloor marine sediments are one of the most extensive microbial habitats on Earth. Marine sediments cover more than two-thirds of the Earth's surface, and represent a major part of the deep biosphere. Owing to its vast size and intimate connection with the surface biosphere, particularly the oceans, the deep biosphere has enormous potential for influencing global-scale biogeochemical processes, including energy, climate, carbon and nutrient cycles. Therefore, studying piezophilic bacteria of the deep biosphere has important implications in increasing our understanding of global biogeochemical cycles, the interactions between the biosphere and the geosphere, and the evolution of life. Sediment samples were obtained during IODP Expedition 337, from 1498 meters below sea floor (mbsf) (Sample 6R-3), 1951~1999 mbsf (19R-1~25R-3; coalbed mix), and 2406 mbsf (29R-7). The samples were mixed with MB2216 growth medium and cultivated under anaerobic conditions at 35 MPa (megapascal) pressure. Growth temperatures were adjusted to in situ environmental conditions, 35°C for 6R-3, 45°C for 19R-1~25R-3, and 55°C for 29R-7. The cultivation was performed three times, for 30 days each time. Microbial cells were obtained and the total DNA was extracted. At the same time, isolation of microbes was also performed under anaerobic conditions. Microbial communities in the coalbed sediment were analyzed by cloning, sequencing, and terminal restriction fragment length polymorphism (t-RFLP) of 16S ribosomal RNA genes. From the partial 16S r

  20. Tracking solutes and water from subsurface drip irrigation application of coalbed methane–produced waters, Powder River Basin, Wyoming

    SciTech Connect

    Engle, Mark A.; Bern, Carleton R.; Healy, Richard W.; Sams, James I.; Zupancic, John W.; Schroeder, Karl T.

    2011-09-01

    One method to beneficially use water produced from coalbed methane (CBM) extraction is subsurface drip irrigation (SDI) of croplands. In SDI systems, treated CBM water (injectate) is supplied to the soil at depth, with the purpose of preventing the buildup of detrimental salts near the surface. The technology is expanding within the Powder River Basin, but little research has been published on its environmental impacts. This article reports on initial results from tracking water and solutes from the injected CBM-produced waters at an SDI system in Johnson County, Wyoming. In the first year of SDI operation, soil moisture significantly increased in the SDI areas, but well water levels increased only modestly, suggesting that most of the water added was stored in the vadose zone or lost to evapotranspiration. The injectate has lower concentrations of most inorganic constituents relative to ambient groundwater at the site but exhibits a high sodium adsorption ratio. Changes in groundwater chemistry during the same period of SDI operation were small; the increase in groundwater-specific conductance relative to pre-SDI conditions was observed in a single well. Conversely, groundwater samples collected beneath another SDI field showed decreased concentrations of several constituents since the SDI operation. Groundwater-specific conductance at the 12 other wells showed no significant changes. Major controls on and compositional variability of groundwater, surface water, and soil water chemistry are discussed in detail. Findings from this research provide an understanding of water and salt dynamics associated with SDI systems using CBM-produced water.

  1. Implications of coal-bed splitting for assessing coal resources

    SciTech Connect

    Thacker, E.E.; Weisenfluh, G.A.

    1998-12-31

    Appalachian Basin coal beds are noted for their characteristic of splitting that arose from deposition of detritus between benches of mineable seams. The increase in thickness of this parting material commonly defines the limit of mining for such beds. The complex stratigraphic nature of coal zones with this property are difficult to characterize in a two-dimensional framework, and present serious challenges to determining and coding correlations for tabular databases. Delineation of split lines on coal-bed maps has two advantages in coal bed assessment. First, it imparts information that relates directly to mineability. More important, the resulting subdivisions of regional areas become more homogeneous with respect to thickness and quality variation and this reduces the amounts of data necessary for assessment.

  2. Methane Plumes on Mars

    NASA Video Gallery

    Spectrometer instruments attached to several telescopes detect plumes of methane emitted from Mars during its summer and spring seasons. High levels of methane are indicated by warmer colors. The m...

  3. Up with methane

    SciTech Connect

    Barlaz, M.A.; Milke, M.W.; Ham, R.K.

    1986-12-01

    Methane production from municipal refuse represents a rapidly developing source of energy which remains underutilized. Part of the problem is the small amount of methane which is typically collected relative to the refuse's methane generation potential. This study was undertaken to define the parameters which affect the onset of methane production and methane yields in sanitary landfills. Ultimately, we need to develop refuse disposal methods which enhance its methane production potential. Included in the study were tests of how introduction of old refuse, use of sterile cover soil, addition of acetate to refuse, and use of leachate, recycling and neutralization affect methane generation. A more thorough understanding of how the microbes present in refuse react to different variables is the first step in the development of techniques for stimulating methane production in sanitary landfills.

  4. Phospholipid-Derived Fatty Acids and Their Stable and Radiocarbon Isotope Values as Indicators of Bacterial Methane Oxidation at a Thermogenic Methane Seep

    NASA Astrophysics Data System (ADS)

    Mills, C. T.; Dias, R. F.; Slater, G. F.; Reddy, C. M.; Mandernack, K. W.

    2004-12-01

    The importance of aerobic methanotrophy as a filter for biogenic methane emissions is well documented for environments such as natural wetlands, landfills, and rice paddies, but less is known about methane oxidation in soils overlying thermogenic methane seeps. We are utilizing phospholipid-derived fatty acids (PLFAs) extracted from soils overlying a high-rate, coal-bed methane seep in Southwestern Colorado to investigate the location and extent of bacterial methane consumption within the soil column. PLFAs have been widely used as indicators of both quantities and types of viable bacterial populations. Two specific PLFAs, 16:1ω 8 and 18:1ω 8, appear to be unique to type I and type II methanotrophs, respectively. We have detected higher abundances of these methanotroph biomarkers in surface soils ( ˜0-30 cm) under wetter soil conditions and near the water table ( ˜150 cm) under drier conditions. Maximum concentrations of both type I and type II methanotroph PLFA biomarkers were greatest in the shallow soils during wetter conditions with the type I maximum located just above the type II maximum. This is consistent with pure culture studies that have shown type I methanotrophs to prefer higher oxygen, lower methane conditions and type II methanotrophs to prefer lower oxygen, higher methane conditions. Soil gas methane concentrations during this wetter period were approximately 30% at 20 cm depth and 80% at 100 cm depth. During a drier period a type II methanotroph biomarker maximum was observed near the water table but no type I maximum was observed. Soil gas methane concentrations at this time were less than 1% at 20 cm and 25% at 100 cm. These data suggest that methanotrophs may consume a significant fraction of the methane as it rises through the soil column. Greater saturation of soil pore spaces during wetter conditions may inhibit atmospheric oxygen diffusion into deeper soils forcing methanotrophs to reside in the shallow soils and resulting in larger

  5. Heat pipe methanator

    DOEpatents

    Ranken, William A.; Kemme, Joseph E.

    1976-07-27

    A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

  6. Methane photochemistry and methane production on Neptune

    NASA Astrophysics Data System (ADS)

    Romani, P. N.; Atreya, S. K.

    1988-06-01

    The Neptune stratosphere's methane photochemistry is presently studied by means of a numerical model in which the observed mixing ratio of methane prompts photolysis near the CH4 homopause. Haze generation by methane photochemistry has its basis in the formation of hydrocarbon ices and polyacetylenes; the hazes can furnish the requisite aerosol haze at the appropriate pressure levels required by observations of Neptune in the visible and near-IR. Comparisons of model predictions with Uranus data indicate a lower ratio of polyacetylene production to hydrocarbon ice, as well as a lower likelihood of UV postprocessing of the acetylene ice to polymers on Neptune, compared to Uranus.

  7. Methane photochemistry and methane production on Neptune

    NASA Technical Reports Server (NTRS)

    Romani, P. N.; Atreya, S. K.

    1988-01-01

    The Neptune stratosphere's methane photochemistry is presently studied by means of a numerical model in which the observed mixing ratio of methane prompts photolysis near the CH4 homopause. Haze generation by methane photochemistry has its basis in the formation of hydrocarbon ices and polyacetylenes; the hazes can furnish the requisite aerosol haze at the appropriate pressure levels required by observations of Neptune in the visible and near-IR. Comparisons of model predictions with Uranus data indicate a lower ratio of polyacetylene production to hydrocarbon ice, as well as a lower likelihood of UV postprocessing of the acetylene ice to polymers on Neptune, compared to Uranus.

  8. Methane photochemistry and methane production on Neptune

    SciTech Connect

    Romani, P.N.; Atreya, S.K.

    1988-06-01

    The Neptune stratosphere's methane photochemistry is presently studied by means of a numerical model in which the observed mixing ratio of methane prompts photolysis near the CH4 homopause. Haze generation by methane photochemistry has its basis in the formation of hydrocarbon ices and polyacetylenes; the hazes can furnish the requisite aerosol haze at the appropriate pressure levels required by observations of Neptune in the visible and near-IR. Comparisons of model predictions with Uranus data indicate a lower ratio of polyacetylene production to hydrocarbon ice, as well as a lower likelihood of UV postprocessing of the acetylene ice to polymers on Neptune, compared to Uranus. 65 references.

  9. Map of assessed coalbed-gas resources in the United States, 2014

    USGS Publications Warehouse

    ,; Biewick, Laura R. H.

    2014-01-01

    This report presents a digital map of coalbed-gas resource assessments in the United States as part of the U.S. Geological Survey’s (USGS) National Assessment of Oil and Gas Project. Using a geology-based assessment methodology, the USGS quantitatively estimated potential volumes of undiscovered, technically recoverable natural gas resources within coalbed-gas assessment units (AUs). This is the third digital map product in a series of USGS unconventional oil and gas resource maps. The map plate included in this report can be printed in hardcopy form or downloaded in a Geographic Information System (GIS) data package, including an ArcGIS ArcMap document (.mxd), geodatabase (.gdb), and published map file (.pmf). In addition, the publication access table contains hyperlinks to current USGS coalbed-gas assessment publications and web pages.

  10. The distribution of methane in groundwater in Alberta (Canada) and associated aqueous geochemistry conditions

    NASA Astrophysics Data System (ADS)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Millot, Romain; Kloppmann, Wolfram

    2016-04-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish: (a) natural in-situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. We have conducted a NSERC-ANR co-funded baseline study investigating the occurrence of methane in shallow groundwater of Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. Our objective was to assess the occurrence and sources of methane in shallow groundwaters and to also characterize the hydrochemical environment in which the methane was formed or transformed through redox processes. Ultimately our aim was to determine whether methane was formed in-situ or whether it migrated from deeper formations into shallow aquifers. Combining hydrochemical and dissolved and free geochemical gas data from 372 groundwater samples obtained from 186 monitoring wells of the provincial groundwater observation well network (GOWN) in Alberta, it was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of dissolved biogenic methane (> 0.01 mM or > 0.2 mg/L), characterized by δ13CCH4 values < -55‰, occurred in anoxic Na-Cl, Na-HCO3 and Na-HCO3-Cl type groundwater with negligible concentrations of nitrate and sulfate suggesting that methane was formed in-situ under methanogenic conditions consistent with the redox ladder concept. Despite quite variable gas concentrations and a

  11. Methane emission from sewers.

    PubMed

    Liu, Yiwen; Ni, Bing-Jie; Sharma, Keshab R; Yuan, Zhiguo

    2015-08-15

    Recent studies have shown that sewer systems produce and emit a significant amount of methane. Methanogens produce methane under anaerobic conditions in sewer biofilms and sediments, and the stratification of methanogens and sulfate-reducing bacteria may explain the simultaneous production of methane and sulfide in sewers. No significant methane sinks or methanotrophic activities have been identified in sewers to date. Therefore, most of the methane would be emitted at the interface between sewage and atmosphere in gravity sewers, pumping stations, and inlets of wastewater treatment plants, although oxidation of methane in the aeration basin of a wastewater treatment plant has been reported recently. Online measurements have also revealed highly dynamic temporal and spatial variations in methane production caused by factors such as hydraulic retention time, area-to-volume ratio, temperature, and concentration of organic matter in sewage. Both mechanistic and empirical models have been proposed to predict methane production in sewers. Due to the sensitivity of methanogens to environmental conditions, most of the chemicals effective in controlling sulfide in sewers also suppress or diminish methane production. In this paper, we review the recent studies on methane emission from sewers, including the production mechanisms, quantification, modeling, and mitigation. PMID:25889543

  12. Methane emission from sewers.

    PubMed

    Liu, Yiwen; Ni, Bing-Jie; Sharma, Keshab R; Yuan, Zhiguo

    2015-08-15

    Recent studies have shown that sewer systems produce and emit a significant amount of methane. Methanogens produce methane under anaerobic conditions in sewer biofilms and sediments, and the stratification of methanogens and sulfate-reducing bacteria may explain the simultaneous production of methane and sulfide in sewers. No significant methane sinks or methanotrophic activities have been identified in sewers to date. Therefore, most of the methane would be emitted at the interface between sewage and atmosphere in gravity sewers, pumping stations, and inlets of wastewater treatment plants, although oxidation of methane in the aeration basin of a wastewater treatment plant has been reported recently. Online measurements have also revealed highly dynamic temporal and spatial variations in methane production caused by factors such as hydraulic retention time, area-to-volume ratio, temperature, and concentration of organic matter in sewage. Both mechanistic and empirical models have been proposed to predict methane production in sewers. Due to the sensitivity of methanogens to environmental conditions, most of the chemicals effective in controlling sulfide in sewers also suppress or diminish methane production. In this paper, we review the recent studies on methane emission from sewers, including the production mechanisms, quantification, modeling, and mitigation.

  13. Methane-Powered Vehicles

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Liquid methane is beginning to become an energy alternative to expensive oil as a power source for automotive vehicles. Methane is the principal component of natural gas, costs less than half as much as gasoline, and its emissions are a lot cleaner than from gasoline or diesel engines. Beech Aircraft Corporation's Boulder Division has designed and is producing a system for converting cars and trucks to liquid methane operation. Liquid methane (LM) is a cryogenic fuel which must be stored at a temperature of 260 degrees below zero Fahrenheit. The LM system includes an 18 gallon fuel tank in the trunk and simple "under the hood" carburetor conversion equipment. Optional twin-fuel system allows operator to use either LM or gasoline fuel. Boulder Division has started deliveries for 25 vehicle conversions and is furnishing a liquid methane refueling station. Beech is providing instruction for Northwest Natural Gas, for conversion of methane to liquid state.

  14. Mars methane engine

    NASA Technical Reports Server (NTRS)

    Bui, Hung; Coletta, Chris; Debois, Alain

    1994-01-01

    The feasibility of an internal combustion engine operating on a mixture of methane, carbon dioxide, and oxygen has been verified by previous design groups for the Mars Methane Engine Project. Preliminary stoichiometric calculations examined the theoretical fuel-air ratios needed for the combustion of methane. Installation of a computer data acquisition system along with various ancillary components will enable the performance of the engine, running on the described methane mixture, to be optimized with respect to minimizing excess fuel. Theoretical calculations for stoichiometric combustion of methane-oxygen-carbon dioxide mixtures yielded a ratio of 1:2:4.79 for a methane-oxygen-carbon dioxide mixture. Empirical data shows the values to be closer to 1:2.33:3.69 for optimum operation.

  15. Detecting Methane Leaks

    NASA Technical Reports Server (NTRS)

    Grant, W. B.; Hinkley, E. D.

    1984-01-01

    Remote sensor uses laser radiation backscattered from natural targets. He/Ne Laser System for remote scanning of Methane leaks employs topographic target to scatter light to receiver near laser transmitter. Apparatus powered by 1.5kW generator transported to field sites and pointed at suspected methane leaks. Used for remote detection of natural-gas leaks and locating methane emissions in landfill sites.

  16. Methane emissions from cattle.

    PubMed

    Johnson, K A; Johnson, D E

    1995-08-01

    Increasing atmospheric concentrations of methane have led scientists to examine its sources of origin. Ruminant livestock can produce 250 to 500 L of methane per day. This level of production results in estimates of the contribution by cattle to global warming that may occur in the next 50 to 100 yr to be a little less than 2%. Many factors influence methane emissions from cattle and include the following: level of feed intake, type of carbohydrate in the diet, feed processing, addition of lipids or ionophores to the diet, and alterations in the ruminal microflora. Manipulation of these factors can reduce methane emissions from cattle. Many techniques exist to quantify methane emissions from individual or groups of animals. Enclosure techniques are precise but require trained animals and may limit animal movement. Isotopic and nonisotopic tracer techniques may also be used effectively. Prediction equations based on fermentation balance or feed characteristics have been used to estimate methane production. These equations are useful, but the assumptions and conditions that must be met for each equation limit their ability to accurately predict methane production. Methane production from groups of animals can be measured by mass balance, micrometeorological, or tracer methods. These techniques can measure methane emissions from animals in either indoor or outdoor enclosures. Use of these techniques and knowledge of the factors that impact methane production can result in the development of mitigation strategies to reduce methane losses by cattle. Implementation of these strategies should result in enhanced animal productivity and decreased contributions by cattle to the atmospheric methane budget.

  17. Gas Hydrates and Perturbed Permafrost: Can Thermokarst Lakes Leak Hydrate-Derived Methane?

    NASA Astrophysics Data System (ADS)

    Ruppel, C.; Walter, K.; Pohlman, J.; Wooller, M.

    2008-12-01

    Thermokarst lakes are common features in the continuous permafrost of Siberia, the Alaskan North Slope, and the Canadian Arctic and have been intensely studied as the loci of rapid and substantial methane flux to the atmosphere. Previous numerical modeling has constrained the conditions under which deep thermokarst lakes can develop organic-rich thaw bulbs (talik) tens of meters thick, and seismic surveys have imaged thaw bulbs more than 75 m thick beneath some thermokarst lakes. Microbial processes active in talik organic material are likely the predominant source for thermokarst methane emissions, although coalbed methane and methane associated with conventional hydrocarbons may contribute in some geologic settings. Here we evaluate the possibility that another source--methane released from dissociating gas hydrate--could contribute to methane emissions from these lakes. Temperatures within and beneath thermokarst lakes are significantly warmer than those in surrounding permafrost, and these relatively warm conditions can persist to depths several times greater than the thickness of the thaw bulb. For a 95-m-thick thaw bulb and a geothermal gradient consistent with the regional top of gas hydrate stability at ~200 m depth, the warmer temperatures beneath a thermokarst lake could lead to destabilization of up to 75 m of gas hydrate. Arguably, the presence of gas hydrate near the top of the stability zone in permafrost regions has not yet been observed. Nonetheless, the potential dissociation of such relatively shallow gas hydrate and the widespread availability in terrestrial settings of high permeability conduits (e.g., faults, sandy strata) that could facilitate the migration of hydrate-derived methane to the surface render this an important topic for future investigation. The susceptibility of permafrost gas hydrate zones to thermal perturbations is in sharp contrast to the situation in conventional marine hydrate provinces. There, gas hydrate first dissociates

  18. Seafloor methane: Atlantic bubble bath

    NASA Astrophysics Data System (ADS)

    Kessler, John

    2014-09-01

    The release of large quantities of methane from ocean sediments might affect global climate change. The discovery of expansive methane seeps along the US Atlantic margin provides an ideal test bed for such a marine methane-climate connection.

  19. Geologic Sequestration of CO2 in Deep, Unmineable Coalbeds: An Integrated Researdh and Commercial-Scale Field Demonstration Project

    SciTech Connect

    Scott Reeves; George Koperna

    2008-09-30

    The Coal-Seq consortium is a government-industry collaborative consortium with the objective of advancing industry's understanding of complex coalbed methane and gas shale reservoir behavior in the presence of multi-component gases via laboratory experiments, theoretical model development and field validation studies. This will allow primary recovery, enhanced recovery and CO{sub 2} sequestration operations to be commercially enhanced and/or economically deployed. The project was initially launched in 2000 as a U.S. Department of Energy sponsored investigation into CO{sub 2} sequestration in deep, unmineable coalseams. The initial project accomplished a number of important objectives, which mainly revolved around performing baseline experimental studies, documenting and analyzing existing field projects, and establishing a global network for technology exchange. The results from that Phase have been documented in a series of reports which are publicly available. An important outcome of the initial phase was that serious limitations were uncovered in our knowledge of reservoir behavior when CO{sub 2} is injected into coal. To address these limitations, the project was extended in 2005 as a government-industry collaborative consortium. Selected accomplishments from this phase have included the identification and/or development of new models for multi-component sorption and diffusion, laboratory studies of coal geomechanical and permeability behavior with CO{sub 2} injection, additional field validation studies, and continued global technology exchange. Further continuation of the consortium is currently being considered. Some of the topics that have been identified for investigation include further model development/refinement related to multicomponent equations-of-state, sorption and diffusion behavior, geomechanical and permeability studies, technical and economic feasibility studies for major international coal basins, the extension of the work to gas shale

  20. The future of methane

    SciTech Connect

    Howell, D.G.

    1995-12-31

    Natural gas, mainly methane, produces lower CO{sub 2}, CO, NO{sub x}, SO{sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce ca. 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the above rates of recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions steming from the need to drill an enormous number of wells, many in ecologically sensitive areas. Until all these aspects of methane are better understood, its future role in the world`s energy mix will remain uncertain. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity and importance of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.

  1. Assessment of Appalachian basin oil and gas resources: Carboniferous Coal-bed Gas Total Petroleum System: Chapter G.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Milici, Robert C.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Trap formation began with the deposition of the peat deposits during the Mississippian and continued into the Late Pennsylvanian and Permian, when strata of the Appalachian Plateaus were deformed during the Alleghanian orogeny. The seals are the connate waters that occupy fractures and larger pore spaces within the coal beds, as well as the fine-grained, siliciclastic sedimentary strata that are intercalated with the coal. The critical moment for the petroleum system occurred during the Alleghanian orogeny, when deformation resulted in the geologic structures in the eastern part of the Appalachian basin that enhanced fracture porosity within the coal beds. In places, burial by thrust sheets (thrust loading) in the Valley and Ridge physiographic province may have resulted in the additional generation of thermogenic coalbed methane in the Pennsylvania Anthracite region and in the semianthracite deposits of Virginia and West Virginia, although other explanations have been offered.

  2. Methanation assembly using multiple reactors

    DOEpatents

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  3. Effects of stimulation treatments on coalbeds and surrounding strata. Evidence from underground observations

    SciTech Connect

    Diamond, W.P.; Oyler, D.C.

    1987-01-01

    This Bureau of Mines report examines the coal mine roof damage potential of stimulation treatments. Vertical fractures in the coalbed were discernible for most treatments, and horizontal fractures were present for about half of the stimulations. Evidence of stimulation fluid movement could generally be traced beyond the maximum extent of sand-filled fractures when fluorescent paint was added to the treatment fluids.

  4. Methane drizzle on Titan.

    PubMed

    Tokano, Tetsuya; McKay, Christopher P; Neubauer, Fritz M; Atreya, Sushil K; Ferri, Francesca; Fulchignoni, Marcello; Niemann, Hasso B

    2006-07-27

    Saturn's moon Titan shows landscapes with fluvial features suggestive of hydrology based on liquid methane. Recent efforts in understanding Titan's methane hydrological cycle have focused on occasional cloud outbursts near the south pole or cloud streaks at southern mid-latitudes and the mechanisms of their formation. It is not known, however, if the clouds produce rain or if there are also non-convective clouds, as predicted by several models. Here we show that the in situ data on the methane concentration and temperature profile in Titan's troposphere point to the presence of layered optically thin stratiform clouds. The data indicate an upper methane ice cloud and a lower, barely visible, liquid methane-nitrogen cloud, with a gap in between. The lower, liquid, cloud produces drizzle that reaches the surface. These non-convective methane clouds are quasi-permanent features supported by the global atmospheric circulation, indicating that methane precipitation occurs wherever there is slow upward motion. This drizzle is a persistent component of Titan's methane hydrological cycle and, by wetting the surface on a global scale, plays an active role in the surface geology of Titan.

  5. Methane conversion process

    SciTech Connect

    Gaffney, A.M.; Jones, C.A.; Sofranko, J.A.

    1989-01-03

    This patent describes a process for the conversion of methane to higher hydrocarbons and coproduct water wherein methane is contacted at reactive conditions with a conversion catalyst comprised of a reducible metal oxide selected from the group consisting of an oxide of manganese, tin, indium, germanium, antimony, leads, bismuth, cerium, praseodymium, terbium, iron, and ruthenium. The improvement consists of: pretreating the catalyst before use in the conversion of methane to higher hydrocarbons and coproduct water with a reducing agent at 650/sup 0/C to 1200/sup 0/C for a time sufficient to improve the bulk density and attrition resistance of the catalyst and thereafter contacting the pretreated catalyst with methane at methane conversion conditions effective to form higher hydrocarbons and coproduct water.

  6. Methane emission by camelids.

    PubMed

    Dittmann, Marie T; Runge, Ullrich; Lang, Richard A; Moser, Dario; Galeffi, Cordula; Kreuzer, Michael; Clauss, Marcus

    2014-01-01

    Methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. Ruminants were found to produce more enteric methane than other mammalian herbivores. As camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. This is of special relevance for countrywide greenhouse gas budgets of countries that harbor large populations of camelids like Australia. However, hardly any quantitative methane emission measurements have been performed in camelids. In order to fill this gap, we carried out respiration chamber measurements with three camelid species (Vicugna pacos, Lama glama, Camelus bactrianus; n = 16 in total), all kept on a diet consisting of food produced from alfalfa only. The camelids produced less methane expressed on the basis of body mass (0.32±0.11 L kg⁻¹ d⁻¹) when compared to literature data on domestic ruminants fed on roughage diets (0.58±0.16 L kg⁻¹ d⁻¹). However, there was no significant difference between the two suborders when methane emission was expressed on the basis of digestible neutral detergent fiber intake (92.7±33.9 L kg⁻¹ in camelids vs. 86.2±12.1 L kg⁻¹ in ruminants). This implies that the pathways of methanogenesis forming part of the microbial digestion of fiber in the foregut are similar between the groups, and that the lower methane emission of camelids can be explained by their generally lower relative food intake. Our results suggest that the methane emission of Australia's feral camels corresponds only to 1 to 2% of the methane amount produced by the countries' domestic ruminants and that calculations of greenhouse gas budgets of countries with large camelid populations based on equations developed for ruminants are generally overestimating the actual levels.

  7. Development and utilization strategies for recovery and utilization of coal mine methane

    SciTech Connect

    Byrer, C.W.; Layne, A.W.; Guthrie, H.D.

    1995-10-01

    The U.S. Department of Energy (DOE), at its Morgantown Energy Technology Center, has been involved in natural gas research since the 1970`s. DOE has assessed the potential of gas in coals throughout the U.S. and promoted research and development for recovery and use of methane found in minable and unminable coalbeds. DOE efforts have focused on the use of coal mine methane for regional economic gas self-sufficiency, energy parks, self-help initiatives, and small-power generation. This paper focuses on DOE`s past and present efforts to more effectively and efficiently recover and use this valuable domestic energy source. The Climate Change Action Plan (CCAP) (1) lists a series of 50 voluntary initiatives designed to reduce greenhouse gas emissions, such as methane from mining operations, to their 1990 levels. Action No. 36 of the CCAP expands the DOE research, development, and demonstration (RD&D) efforts to broaden the range of cost-effective technologies and practices for recovering methane associated with coal mining operations. The major thrust of Action No. 36 is to reduce methane emissions associated with coal mining operations from target year 2000 levels by 1.5 MMT of carbon equivalent. Crosscutting activities in the DOE Natural Gas Program supply the utilization sectors will address RD&D to reduce methane emissions released from various mining operations, focusing on recovery and end use technology systems to effectively drain, capture, and utilize the emitted gas. Pilot projects with industry partners will develop and test the most effective methods and technology systems for economic recovery and utilization of coal mine gas emissions in regions where industry considers efforts to be presently non-economic. These existing RD&D programs focus on near-term gas recovery and gathering systems, gas upgrading, and power generation.

  8. Relative importance of physical and economic factors in Appalachian coalbed gas assessment

    USGS Publications Warehouse

    Attanasi, E.D.

    1998-01-01

    In the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey, only 20% of the assessed technically recoverable Appalachian Province coalbed gas resources were economic. Physical and economic variables are examined to explain the disparity between economic and technically recoverable coalbed gas. The Anticline and Syncline plays of the Northern Appalachian Basin, which account for 77% of the assessed technically recoverable coalbed gas, are not economic. Analysis shows marginal reductions in costs or rate of return will not turn these plays into commercial successes. Physical parameters that determine ultimate well recoverability and the rate of gas recovery are primary reasons the Northern Appalachian Basin plays are non-commercial. If the application of new well stimulation technology could offset slow gas desorption rates, Appalachian Province economic gas could increase to more then 70% of the technically recoverable gas. Similarly, if operators are able to develop strategies to selectively drill plays by avoiding dry holes and non-commercial occurrences, the economic fraction of technically recoverable gas could increase to over half.In the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey, only 20% of the assessed technically recoverable Appalachian Province coalbed gas resources were economic. Physical and economic variables are examined to explain the disparity between economic and technically recoverable coalbed gas. The Anticline and Syncline plays of the Northern Appalachian Basin, which account for 77% of the assessed technically recoverable coalbed gas, are not economic. Analysis shows marginal reductions in costs or rate of return will not turn these plays into commercial successes. Physical parameters that determine ultimate well recoverability and the rate of gas recovery are primary reasons the Northern Appalachian Basin plays are non-commercial. If the application of new well

  9. Mars Methane Plume Tracer

    NASA Astrophysics Data System (ADS)

    Mischna, M. A.; Banfield, D.; Sykes, I.

    2014-07-01

    Putative releases of methane from the martian surface may be challenging to detect from orbit. Successful detections depend on the character of the plume itself (duration, magnitude, expanse), but also on the observing platform.

  10. Methane heat transfer investigation

    NASA Technical Reports Server (NTRS)

    Cook, R. T.

    1984-01-01

    Future high chamber pressure LOX/hydrocarbon booster engines require copper-base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and resuable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper-base alloy material adjacent to the fuel coolant. High-pressure methane cooling and coking characteristics were recently evaluated using stainless-steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper-base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.

  11. Methane heat transfer investigation

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Future high chamber pressure LOX/hydrocarbon booster engines require copper base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and reusable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper base alloy material adjacent to he fuel coolant. High pressure methane cooling and coking characteristics recently evaluated at Rocketdyne using stainless steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.

  12. Enzymatic Oxidation of Methane

    SciTech Connect

    Sirajuddin, S; Rosenzweig, AC

    2015-04-14

    Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, proteinprotein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.

  13. Electrochemical methane sensor

    DOEpatents

    Zaromb, S.; Otagawa, T.; Stetter, J.R.

    1984-08-27

    A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about 1.4 volts vs R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.

  14. Laser beam methane detector

    NASA Technical Reports Server (NTRS)

    Hinkley, E. D., Jr.

    1981-01-01

    Instrument uses infrared absorption to determine methane concentration in liquid natural gas vapor. Two sensors measure intensity of 3.39 mm laser beam after it passes through gas; absorption is proportional to concentration of methane. Instrument is used in modeling spread of LNG clouds and as leak detector on LNG carriers and installations. Unit includes wheels for mobility and is both vertically and horizontally operable.

  15. Methane Emissions from Upland Forests

    NASA Astrophysics Data System (ADS)

    Megonigal, Patrick; Pitz, Scott; Wang, Zhi-Ping

    2016-04-01

    Global budgets ascribe 4-10% of atmospheric methane sinks to upland soils and assume that soils are the sole surface for methane exchange between upland forests and the atmosphere. The dogma that upland forests are uniformly atmospheric methane sinks was challenged a decade ago by the discovery of abiotic methane production from plant tissue. Subsequently a variety of relatively cryptic microbial and non-microbial methane sources have been proposed that have the potential to emit methane in upland forests. Despite the accumulating evidence of potential methane sources, there are few data demonstrating actual emissions of methane from a plant surface in an upland forest. We report direct observations of methane emissions from upland tree stems in two temperate forests. Stem methane emissions were observed from several tree species that dominate a forest located on the mid-Atlantic coast of North America (Maryland, USA). Stem emissions occurred throughout the growing season while soils adjacent to the trees simultaneously consumed methane. Scaling fluxes by stem surface area suggested the forest was a net methane source during a wet period in June, and that stem emissions offset 5% of the soil methane sink on an annual basis. High frequency measurements revealed diurnal cycles in stem methane emission rates, pointing to soils as the methane source and transpiration as the most likely pathway for gas transport. Similar observations were made in an upland forest in Beijing, China. However, in this case the evidence suggested the methane was not produced in soils, but in the heartwood by microbial or non-microbial processes. These data challenge the concept that forests are uniform sinks of methane, and suggest that upland forests are smaller methane sinks than previously estimated due to stem emissions. Tree emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration.

  16. Hydrologic properties of coal-beds in the Powder River Basin, Montana. II. Aquifer test analysis

    USGS Publications Warehouse

    Weeks, E.P.

    2005-01-01

    A multiple well aquifer test to determine anisotropic transmissivity was conducted on a coal-bed in the Powder River Basin, southeastern Montana, as part of a multidisciplinary investigation to determine hydrologic conditions of coal-beds in the area. For the test, three wells were drilled equidistant from and at different angles to a production well tapping the Flowers-Goodale coal seam, a 7.6-m thick seam confined at a depth of about 110 m. The test was conducted by air-lift pumping for 9 h, and water levels were monitored in the three observation wells using pressure transducers. Drawdown data collected early in the test were affected by interporosity flow between the coal fracture network and the matrix, but later data were suitable to determine aquifer anisotropy, as the slopes of the late-time semilog time-drawdown curves are nearly identical, and the zero-drawdown intercepts are different. The maximum transmissivity, trending N87??E, is 14.9 m2/d, and the minimum transmissivity 6.8 m2/d, giving an anisotropy ratio of 2.2:1. Combined specific storage of the fractures and matrix is 2??10 -5/m, and of the fracture network alone 5??10-6/m. The principal direction of the anisotropy tensor is not aligned with the face cleats, but instead is aligned with another fracture set and with dominant east-west tectonic compression. Results of the test indicate that the Flowers-Goodale coal-bed is more permeable than many coals in the Powder River Basin, but the anisotropy ratio and specific storage are similar to those found for other coal-beds in the basin.

  17. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    SciTech Connect

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  18. Characteristics of slush and boiling methane and methane mixtures.

    NASA Technical Reports Server (NTRS)

    Sindt, C. F.; Ludtke, P. R.

    1971-01-01

    Methane gas of two purities, 99.97% and 99%, was condensed to study the characteristics of the boiling liquid and the slush. In addition, binary mixtures of nitrogen and methane, and those of ethane and methane, and propane and methane, were also studied. Potential advantages of these gases when employed as fuels for high-performance aircraft, rocket engines, and motor vehicles are emphasized.

  19. Combustion of Methane Hydrate

    NASA Astrophysics Data System (ADS)

    Roshandell, Melika

    A significant methane storehouse is in the form of methane hydrates on the sea floor and in the arctic permafrost. Methane hydrates are ice-like structures composed of water cages housing a guest methane molecule. This caged methane represents a resource of energy and a potential source of strong greenhouse gas. Most research related to methane hydrates has been focused on their formation and dissociation because they can form solid plugs that complicate transport of oil and gas in pipelines. This dissertation explores the direct burning of these methane hydrates where heat from the combustion process dissociates the hydrate into water and methane, and the released methane fuels the methane/air diffusion flame heat source. In contrast to the pipeline applications, very little research has been done on the combustion and burning characteristics of methane hydrates. This is the first dissertation on this subject. In this study, energy release and combustion characteristics of methane hydrates were investigated both theoretically and experimentally. The experimental study involved collaboration with another research group, particularly in the creation of methane hydrate samples. The experiments were difficult because hydrates form at high pressure within a narrow temperature range. The process can be slow and the resulting hydrate can have somewhat variable properties (e.g., extent of clathration, shape, compactness). The experimental study examined broad characteristics of hydrate combustion, including flame appearance, burning time, conditions leading to flame extinguishment, the amount of hydrate water melted versus evaporated, and flame temperature. These properties were observed for samples of different physical size. Hydrate formation is a very slow process with pure water and methane. The addition of small amounts of surfactant increased substantially the hydrate formation rate. The effects of surfactant on burning characteristics were also studied. One finding

  20. Methane formation and methane oxidation by methanogenic bacteria.

    PubMed Central

    Zehnder, A J; Brock, T D

    1979-01-01

    Methanogenic bacteria were found to form and oxidize methane at the same time. As compared to the quantity of methane formed, the amount of methane simultaneously oxidized varied between 0.3 and 0.001%, depending on the strain used. All the nine tested strains of methane producers (Methanobacterium ruminantium, Methanobacterium strain M.o.H., M. formicicum, M. thermoautotrophicum, M. arbophilicum, Methanobacterium strain AZ, Methanosarcina barkeri, Methanospirillum hungatii, and the "acetate organism") reoxidized methane to carbon dioxide. In addition, they assimilated a small part of the methane supplied into cell material. Methanol and acetate also occurred as oxidation products in M. barkeri cultures. Acetate was also formed by the "acetate organism," a methane bacterium unable to use methanogenic substrates other than acetate. Methane was the precursor of the methyl group of the acetate synthesized in the course of methane oxidation. Methane formation and its oxidation were inhibited equally by 2-bromoethanesulfonic acid. Short-term labeling experiments with M. thermoautotrophicum and M. hungatii clearly suggest that the pathway of methane oxidation is not identical with a simple back reaction of the methane formation process. Images PMID:762019

  1. Chemical and stable isotopic composition of water and gas in the Fort Union Formation of the Powder River Basin, Wyoming and Montana: Evidence for water/rock interaction and the biogenic origin of coalbed natural gas

    USGS Publications Warehouse

    Rice, Cynthia A.; Flores, Romeo M.; Stricker, Gary D.; Ellis, Margaret S.

    2008-01-01

    Significant amounts (> 36 million m3/day) of coalbed methane (CBM) are currently being extracted from coal beds in the Paleocene Fort Union Formation of the Powder River Basin of Wyoming and Montana. Information on processes that generate methane in these coalbed reservoirs is important for developing methods that will stimulate additional production. The chemical and isotopic compositions of gas and ground water from CBM wells throughout the basin reflect generation processes as well as those that affect water/rock interaction. Our study included analyses of water samples collected from 228 CBM wells. Major cations and anions were measured for all samples, δDH2O and δ18OH2O were measured for 199 of the samples, and δDCH4 of gas co-produced with water was measured for 100 of the samples. Results show that (1) water from Fort Union Formation coal beds is exclusively Na–HCO3-type water with low dissolved SO4 content (median < 1 mg/L) and little or no dissolved oxygen (< 0.15 mg/L), whereas shallow groundwater (depth generally < 120 m) is a mixed Ca–Mg–Na–SO4–HCO3 type; (2) water/rock interactions, such as cation exchange on clay minerals and precipitation/dissolution of CaCO3 and SO4 minerals, account for the accumulation of dissolved Na and depletion of Ca and Mg; (3) bacterially-mediated oxidation–reduction reactions account for high HCO3 (270–3310 mg/L) and low SO4 (median < 0.15 mg/L) values; (4) fractionation between δDCH4 (− 283 to − 328 per mil) and δDH2O (− 121 to − 167 per mil) indicates that the production of methane is primarily by biogenic CO2 reduction; and (5) values of δDH2O and δ18OH2O (− 16 to − 22 per mil) have a wide range of values and plot near or above the global meteoric water line, indicating that the original meteoric water has been influenced by methanogenesis and by being mixed with surface and shallow groundwater.

  2. Transformations in methane hydrates

    USGS Publications Warehouse

    Chou, I.-Ming; Sharma, A.; Burruss, R.C.; Shu, J.; Mao, Ho-kwang; Hemley, R.J.; Goncharov, A.F.; Stern, L.A.; Kirby, S.H.

    2000-01-01

    Detailed study of pure methane hydrate in a diamond cell with in situ optical, Raman, and x-ray microprobe techniques reveals two previously unknown structures, structure II and structure H, at high pressures. The structure II methane hydrate at 250 MPa has a cubic unit cell of a = 17.158(2) A?? and volume V = 5051.3(13) A??3; structure H at 600 MPa has a hexagonal unit cell of a = 11.980(2) A??, c = 9.992(3) A??, and V = 1241.9(5) A??3. The compositions of these two investigated phases are still not known. With the effects of pressure and the presence of other gases in the structure, the structure II phase is likely to dominate over the known structure I methane hydrate within deep hydrate-bearing sediments underlying continental margins.

  3. Methane-Powered Airplane

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Beech Aircraft's Corporation's Boulder Division developed expertise in producing superinsulated virtually leak-proof cryogenic equipment for storing liquid oxygen and hydrogen fuels in NASA's Apollo, Skylab and Space Shuttle programs. Boulder Division used this experience in designing a fuel storage tank for liquid methane, a "cryogenic" fuel that must be supercooled to keep it liquid. Beech Aircraft is producing a four-place lightplane powered by liquid methane (LM) which is stored in two of these specially designed cryogenic storage tanks holding 18 gallons each.

  4. Biomimetic methane oxidation

    SciTech Connect

    Watkins, B.E.; Droege, M.W.; Taylor, R.T.; Satcher, J.H.

    1992-06-12

    Methane monooxygenase (MMO) is an enzyme found in methanotrophs that catalyses the selective oxidation of methane to methanol. MMO is protein complex one component of which is a binuclear metal center containing oxygenase. We have completed one round of a design/synthesis/evaluation cycle in the development of coordination complexes that mimic the structure/function of the MMO active site. One of these, a binuclear, coordinately-asymmetric copper complex, is capable of oxidizing cyclohexane to a mixture of cyclohexanol and cyclohexanone in the presence of hydrogen peroxide.

  5. Reduction of Non-CO2 Gas Emissions Through The In Situ Bioconversion of Methane

    SciTech Connect

    Scott, A R; Mukhopadhyay, B; Balin, D F

    2012-09-06

    The primary objectives of this research were to seek previously unidentified anaerobic methanotrophs and other microorganisms to be collected from methane seeps associated with coal outcrops. Subsurface application of these microbes into anaerobic environments has the potential to reduce methane seepage along coal outcrop belts and in coal mines, thereby preventing hazardous explosions. Depending upon the types and characteristics of the methanotrophs identified, it may be possible to apply the microbes to other sources of methane emissions, which include landfills, rice cultivation, and industrial sources where methane can accumulate under buildings. Finally, the microbes collected and identified during this research also had the potential for useful applications in the chemical industry, as well as in a variety of microbial processes. Sample collection focused on the South Fork of Texas Creek located approximately 15 miles east of Durango, Colorado. The creek is located near the subsurface contact between the coal-bearing Fruitland Formation and the underlying Pictured Cliffs Sandstone. The methane seeps occur within the creek and in areas adjacent to the creek where faulting may allow fluids and gases to migrate to the surface. These seeps appear to have been there prior to coalbed methane development as extensive microbial soils have developed. Our investigations screened more than 500 enrichments but were unable to convince us that anaerobic methane oxidation (AMO) was occurring and that anaerobic methanotrophs may not have been present in the samples collected. In all cases, visual and microscopic observations noted that the early stage enrichments contained viable microbial cells. However, as the levels of the readily substrates that were present in the environmental samples were progressively lowered through serial transfers, the numbers of cells in the enrichments sharply dropped and were eliminated. While the results were disappointing we acknowledge that

  6. Methane emissions from natural wetlands

    SciTech Connect

    Meyer, J.L.; Burke, R.A. Jr.

    1993-09-01

    Analyses of air trapped in polar ice cores in conjunction with recent atmospheric measurements, indicate that the atmospheric methane concentration increased by about 250% during the past two or three hundred years (Rasmussen and Khalil, 1984). Because methane is a potent ``greenhouse`` gas, the increasing concentrations are expected to contribute to global warning (Dickinson and Cicerone, 1986). The timing of the methane increase suggests that it is related to the rapid growth of the human population and associated industrialization and agricultural development. The specific causes of the atmospheric methane concentration increase are not well known, but may relate to either increases in methane sources, decreases in the strengths of the sinks, or both.

  7. Direct Aromaization of Methane

    SciTech Connect

    George Marcelin

    1997-01-15

    The thermal decomposition of methane offers significant potential as a means of producing higher unsaturated and aromatic hydrocarbons when the extent of reaction is limited. Work in the literature previous to this project had shown that cooling the product and reacting gases as the reaction proceeds would significantly reduce or eliminate the formation of solid carbon or heavier (Clo+) materials. This project studied the effect and optimization of the quenching process as a means of increasing the amount of value added products during the pyrolysis of methane. A reactor was designed to rapidly quench the free-radical combustion reaction so as to maximize the yield of aromatics. The use of free-radical generators and catalysts were studied as a means of lowering the reaction temperature. A lower reaction temperature would have the benefits of more rapid quenching as well as a more feasible commercial process due to savings realized in energy and material of construction costs. It was the goal of the project to identify promising routes from methane to higher hydrocarbons based on the pyrolysis of methane.

  8. Methane Clathrate Hydrate Prospecting

    NASA Technical Reports Server (NTRS)

    Duxbury, N.; Romanovsky, V.

    2003-01-01

    A method of prospecting for methane has been devised. The impetus for this method lies in the abundance of CH4 and the growing shortages of other fuels. The method is intended especially to enable identification of subpermafrost locations where significant amounts of methane are trapped in the form of methane gas hydrate (CH4(raised dot)6H2O). It has been estimated by the U.S. Geological Survey that the total CH4 resource in CH4(raised dot) 6H2O exceeds the energy content of all other fossil fuels (oil, coal, and natural gas from non-hydrate sources). Also, CH4(raised dot)6H2O is among the cleanest-burning fuels, and CH4 is the most efficient fuel because the carbon in CH4 is in its most reduced state. The method involves looking for a proxy for methane gas hydrate, by means of the combination of a thermal-analysis submethod and a field submethod that does not involve drilling. The absence of drilling makes this method easier and less expensive, in comparison with prior methods of prospecting for oil and natural gas. The proposed method would include thermoprospecting in combination with one more of the other non-drilling measurement techniques, which could include magneto-telluric sounding and/or a subsurface-electrical-resistivity technique. The method would exploit the fact that the electrical conductivity in the underlying thawed region is greater than that in the overlying permafrost.

  9. The potential for coalbed gas exploration and production in the Greater Green River Basin, southwest Wyoming and northwest Colorado

    SciTech Connect

    Tyler, R.; Kaiser, W.R.; Scott, A.R.; Hamilton, D.S.

    1997-01-01

    Coalbed gas is an important source of natural gas in the United States. In 1993, approximately 740 BCF of coalbed gas was produced in the United States, or about 4.2% of the nation`s total gas production. Nearly 96% of this coalbed gas is produced from just two basins, the San Juan (615.7 BCF; gas in place 84 TCF) and Black Warrior (105 BCF; gas in place 20 TCF), and current production represents only a fraction of the nation`s estimated 675 TCF of in-place coalbed gas. Coal beds in the Greater Green River Basin in southwest Wyoming and northwest Colorado hold almost half of the gas in place (314 TCF) and are an important source of gas for low-permeability Almond sandstones. Because total gas in place in the Greater Green River Basin is reported to exceed 3,000 TCF (Law et al., 1989), the basin may substantially increase the domestic gas resource base. Therefore, through integrated geologic and hydrologic studies, the coalbed gas potential of the basin was assessed where tectonic, structural, and depositional setting, coal distribution and rank, gas content, coal permeability, and ground-water flow are critical controls on coalbed gas producibility. Synergism between these geologic and hydrologic controls determines gas productivity. High productivity is governed by (1) thick, laterally continuous coals of high thermal maturity, (2) basinward flow of ground water through fractured and permeable coals, down the coal rank gradient toward no-flow boundaries oriented perpendicular to the regional flow direction, and (3) conventional trapping of gas along those boundaries to provide additional sources of gas beyond that sorbed on the coal surface.

  10. The 4-Corners methane hotspot: Mapping CH4 plumes at 60km through 1m resolution using space- and airborne spectrometers

    NASA Astrophysics Data System (ADS)

    Frankenberg, C.; Thorpe, A. K.; Hook, S. J.; Green, R. O.; Thompson, D. R.; Kort, E. A.; Hulley, G. C.; Vance, N.; Bue, B. D.; Aubrey, A. D.

    2015-12-01

    The SCIAMACHY instrument onboard the European research satellite ENVISAT detected a large methane hotspot in the 4-Corners area, specifically in New Mexico and Colorado. Total methane emissions in this region were estimated to be on the order of 0.5Tg/yr, presumably related to coal-bed methane exploration. Here, we report on NASA efforts to augment the TOPDOWN campaign intended to enable regional methane source inversions and identify source types in this area. The Jet Propulsion Laboratory was funded to fly two airborne imaging spectrometers, viz. AVIRIS-NG and HyTES. In April 2015, we used both instruments to continuously map about 2000km2 in the 4-Corners area at 1-5m spatial resolution, with special focus on the most enhanced areas as observed from space. During our weeklong campaign, we detected more than 50 isolated and strongly enhanced methane plumes, ranging from coal mine venting shafts and gas processing facilities through individual well-pads, pipeline leaks and outcrop. Results could be immediately shared with ground-based teams and TOPDOWN aircraft so that ground-validation and identification was feasible for a number of sources. We will provide a general overview of the JPL-led mapping campaign efforts and show individual results, derive source strength estimates and discuss how the results fit in with space borne estimates.

  11. Methane capture from livestock manure.

    PubMed

    Tauseef, S M; Premalatha, M; Abbasi, Tasneem; Abbasi, S A

    2013-03-15

    It has been estimated that livestock manure contributes about 240 million metric tons of carbon dioxide equivalent of methane to the atmosphere and represents one of the biggest anthropogenic sources of methane. Considering that methane is the second biggest contributor to global warming after carbon dioxide, it is imperative that ways and means are developed to capture as much of the anthropogenic methane as possible. There is a major associated advantage of methane capture: its use as a source of energy which is comparable in 'cleanness' to natural gas. The present review dwells upon the traditional ways of methane capture used in India, China, and other developing countries for providing energy to the rural poor. It then reviews the present status of methane capture from livestock manure in developed countries and touches upon the prevalent trends.

  12. Future methane emissions from animals

    SciTech Connect

    Anastasi, C.; Simpson, V.J. )

    1993-04-20

    The authors project future methane emissions from animals to the year 2025. They review the present estimated sources of methane from enteric fermentation in animals. Ruminant animals produce the highest concentrations of methane. Methane is a byproduct of anaerobic breakdown of carbohydrates by microbes in the digestive tract of herbatious animals. In general the methane production depends on the variety of animal, the quality of the feed, and the feeding level. Since cattle, sheep, and buffalo account for roughly 91% of all animal methane emission, they only study these animals in detail. Results suggest a rise in methane production of roughly 1% per year averaged through 2025. Increasing levels are found to originate from developed countries even though the feedstock levels are lower.

  13. Redox controls on methane formation, migration and fate in shallow aquifers

    NASA Astrophysics Data System (ADS)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Bayegnak, Guy; Millot, Romain; Kloppmann, Wolfram

    2016-07-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish (a) natural in situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. This study combines aqueous and gas (dissolved and free) geochemical and isotope data from 372 groundwater samples obtained from 186 monitoring wells of the provincial Groundwater Observation Well Network (GOWN) in Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. We investigated whether methane occurring in shallow groundwater formed in situ, or whether it migrated into the shallow aquifers from elsewhere in the stratigraphic column. It was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of biogenic methane (> 0.01 mM or > 0.2 mgL-1), characterized by δ13CCH4 values < -55 ‰, occurred in anoxic Na-Cl, Na-HCO3, and Na-HCO3-Cl type groundwaters with negligible concentrations of nitrate and sulfate suggesting that methane was formed in situ under methanogenic conditions for 39.1 % of the samples. In only a few cases (3.7 %) was methane of biogenic origin found in more oxidizing shallow aquifer portions suggesting limited upward migration from deeper methanogenic aquifers. Of the samples, 14.1 % contained methane with δ13CCH4 values > -54 ‰, potentially suggesting a thermogenic origin, but aqueous and isotope

  14. Methane cycling. Nonequilibrium clumped isotope signals in microbial methane.

    PubMed

    Wang, David T; Gruen, Danielle S; Lollar, Barbara Sherwood; Hinrichs, Kai-Uwe; Stewart, Lucy C; Holden, James F; Hristov, Alexander N; Pohlman, John W; Morrill, Penny L; Könneke, Martin; Delwiche, Kyle B; Reeves, Eoghan P; Sutcliffe, Chelsea N; Ritter, Daniel J; Seewald, Jeffrey S; McIntosh, Jennifer C; Hemond, Harold F; Kubo, Michael D; Cardace, Dawn; Hoehler, Tori M; Ono, Shuhei

    2015-04-24

    Methane is a key component in the global carbon cycle, with a wide range of anthropogenic and natural sources. Although isotopic compositions of methane have traditionally aided source identification, the abundance of its multiply substituted "clumped" isotopologues (for example, (13)CH3D) has recently emerged as a proxy for determining methane-formation temperatures. However, the effect of biological processes on methane's clumped isotopologue signature is poorly constrained. We show that methanogenesis proceeding at relatively high rates in cattle, surface environments, and laboratory cultures exerts kinetic control on (13)CH3D abundances and results in anomalously elevated formation-temperature estimates. We demonstrate quantitatively that H2 availability accounts for this effect. Clumped methane thermometry can therefore provide constraints on the generation of methane in diverse settings, including continental serpentinization sites and ancient, deep groundwaters. PMID:25745067

  15. Relation of geology to mine roof conditions in the Pocahontas No. 3 coalbed. Information circular/1982

    SciTech Connect

    Moebs, N.N.; Fern, J.C.

    1982-03-01

    Bureau of Mines studies of mine roof fall problems in the Pocahontas No. 3 Coalbed of southern West Virginia and southwestern Virginia have established that type and sequence of rock are significant factors in roof competence. The poorest conditions occur where the immediate roof consists of slump structures and slickensided rock. The best conditions occur where the roof consists of a sequence that coarsens upward from shale to massive sandy shale. A small manual of color photographs of rock types was devised to aid in identifying drill cores. Proper identifications should enhance the prediction of areas of potential roof problems in advance of mining.

  16. Methane from acetate.

    PubMed

    Ferry, J G

    1992-09-01

    The general features are known for the pathway by which most methane is produced in nature. All acetate-utilizing methanogenic microorganisms contain CODH which catalyzes the cleavage of acetyl-CoA; however, the pathway differs from all other acetate-utilizing anaerobes in that the methyl group is reduced to methane with electrons derived from oxidation of the carbonyl group of acetyl-CoA to CO2. The current understanding of the methanogenic fermentation of acetate provides impressions of nature's novel solutions to problems of methyl transfer, electron transport, and energy conservation. The pathway is now at a level of understanding that will permit productive investigations of these and other interesting questions in the near future. PMID:1512186

  17. Coal Bed Methane Primer

    SciTech Connect

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  18. Methane ocean on Titan?

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    There was an impressive list of names on a recent scientific communication that argues for the existence on Titan of an ocean of liquid methane (CH4) perhaps several hundred meters deep. C. Sagan and S. Dermott with helpful comments by S. Oter, S. Ostro, S. Peale, C. Yoder, W. Thompson, S. Squyres, G. Pettengill, P. Gierasch, and B. Khare speculate that such a methanic ocean, with its Saturnian tides and its tholinian floor, should exist all over Titan's surface; it should unless, they conclude, there is the ‘distracting coincidence [that] … the position of the surface of Titan [is] … near the liquidus in the CH4phase diagram [and, consequently, there is] …almost no methane ocean at all’ (Nature, 300, 731, 1982).We know very little about Titan and its surface; the way of checking into Sagan and Dermott's ideas appears to rest on the interpretation of radar reflectivity data. Preliminary attempts to obtain radar data were made in 1979 with the 305-m Arecibo telescope, but only broad limits resulted. The next opportunity for a measurement at Arecibo comes in the 1990's. Of course, the ideal circumstance would be to send spacecraft equipped with a radar reflectometer for a Titan flyby.

  19. Methane in the Upper Silesian Coal Basin (Poland) - problem of reserves and exploitation

    SciTech Connect

    Wojcik, A.J.

    1995-08-01

    The Upper Silesian Coal Basin (USCB) is the best recognized and the most productive coal basin in Poland. The USCB is primarily defined by the extent of Carboniferous coal-bearing formations. The sedimentary fill displays the stratigraphic record of major progressive inversion phases of the entire Moravo-Silesian basin during the late and post-geosynclinal period of the Variscan orogeny. According to the last estimates the coal reserves occurring above the depth limit of 1500 in are as follows: documented reserves - 58 billion tons, prognostic reserves - 46 billion tons, total - 104 billion tons. The coal type is predominantly vitrinitic, and ash content is reported to be in the range of 11-17% and average sulphur content is 1.13%. The rank of USCB coal is largely controlled by complex coalification processes. It ranges from high volatile bituminous B, through medium volatile bituminous to high rank special coal semi anthracite and anthracite. The methane content of coal seams in USCB varies in a very broad range of 0-22 m{sup 3}/t coal (dry, ash free basis). The average gas content increases considerably within the depth range 600-1000 in from 0.99 to 4.68 m{sup 3}/t coal (daf). In deeper horizons it is more or less stable varying within the range of 4.7-7.0 m{sup 3}/t coal (daf). By this estimate, on average, the methane content is about 12,5 m{sup 3}/ton. There are several estimates of coal-bed methane resources in the USCB based on different methods. The resources are as follows: documented deposits in active mines to 1000 m: 370 BCM, undeveloped deposits to 1000 in: 340 BCM, deposit between 1000 and 1500 m: 590 BCM, total: 1300 BCM. The coalbed gas from this basin is primarily composed of saturated hydrocarbons and Nitrogen which amount to 97 volume percent. The rest is dominant by Carbon dioxide and Hydrogen.

  20. Measurements of methane emissions from natural gas gathering facilities and processing plants: measurement methods

    NASA Astrophysics Data System (ADS)

    Roscioli, J. R.; Yacovitch, T. I.; Floerchinger, C.; Mitchell, A. L.; Tkacik, D. S.; Subramanian, R.; Martinez, D. M.; Vaughn, T. L.; Williams, L.; Zimmerle, D.; Robinson, A. L.; Herndon, S. C.; Marchese, A. J.

    2014-12-01

    Increased natural gas production in recent years has spurred intense interest in methane (CH4) emissions associated with its production, gathering, processing, transmission and distribution. Gathering and processing facilities (G&P facilities) are unique in that the wide range of gas sources (shale, coal-bed, tight gas, conventional, etc.) results in a wide range of gas compositions, which in turn requires an array of technologies to prepare the gas for pipeline transmission and distribution. We present an overview and detailed description of the measurement method and analysis approach used during a 20-week field campaign studying CH4 emissions from the natural gas G&P facilities between October 2013 and April 2014. Dual tracer flux measurements and onsite observations were used to address the magnitude and origins of CH4 emissions from these facilities. The use of a second tracer as an internal standard revealed plume-specific uncertainties in the measured emission rates of 20-47%, depending upon plume classification. Combining downwind methane, ethane (C2H6), carbon monoxide (CO), carbon dioxide (CO2), and tracer gas measurements with onsite tracer gas release allows for quantification of facility emissions, and in some cases a more detailed picture of source locations.

  1. Methane/nitrogen separation process

    DOEpatents

    Baker, R.W.; Lokhandwala, K.A.; Pinnau, I.; Segelke, S.

    1997-09-23

    A membrane separation process is described for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. The authors have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen. 11 figs.

  2. Methane/nitrogen separation process

    DOEpatents

    Baker, Richard W.; Lokhandwala, Kaaeid A.; Pinnau, Ingo; Segelke, Scott

    1997-01-01

    A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

  3. On methane pyrolysis special applications

    NASA Astrophysics Data System (ADS)

    Toncu, D. C.; Toncu, G.; Soleimani, S.

    2015-11-01

    Methane pyrolysis represents one of the most important processes in industrial use, with applications rising from the chemical and petrochemical industry, combustion, materials and protective coatings. Despite the intense research, experimental data lack kinetic aspects, and the thermodynamics involved often leads to inaccurate results when applied to various systems. Carrying out a comparative analysis of several available data on methane pyrolysis, the paper aims to study the phenomenon of methane pyrolysis under different environments (combustion and plasma), concluding on the most possible reaction pathways involved in many of its applications. Computer simulation using different database underlines the conclusion, helping to the understanding of methane pyrolysis importance in future technologies.

  4. Redefining the isotopic boundaries of biogenic methane: Methane from endoevaporites

    NASA Astrophysics Data System (ADS)

    Tazaz, Amanda M.; Bebout, Brad M.; Kelley, Cheryl A.; Poole, Jennifer; Chanton, Jeffrey P.

    2013-06-01

    The recent reports of methane in the atmosphere of Mars, as well as the findings of hypersaline paleoenvironments on that planet, have underscored the need to evaluate the importance of biological (as opposed to geological) trace gas production and consumption, particularly in hypersaline environments. Methane in the atmosphere of Mars may be an indication of extant life, but it may also be a consequence of geologic activity and/or the thermal alteration of ancient organic matter. On Earth these methane sources can be distinguished using stable isotopic analyses and the ratio of methane (C1) to C2 and C3 alkanes present in the gas source (C1/(C2 + C3)). We report here that methane produced in hypersaline environments on Earth has an isotopic composition and alkane content outside the values presently considered to indicate a biogenic origin. Methane-rich bubbles released from sub-aqueous substrates contained δ13CCH4 and δ2HCH4 values ranging from -65‰ to -35‰ and -350‰ to -140‰ respectively. Higher salinity endoevaporites yielded what would be considered non-biogenic methane based upon stable isotopic and alkane content, however incubation of crustal and algal mat samples resulted in methane production with similar isotopic values. Radiocarbon analysis indicated that the production of the methane was from recently fixed carbon. An extension of the isotopic boundaries of biogenic methane is necessary in order to avoid the possibility of false negatives returned from measurements of methane on Mars and other planetary bodies.

  5. Consumption of atmospheric methane by tundra soils

    NASA Technical Reports Server (NTRS)

    Whalen, S. C.; Reeburgh, W. S.

    1990-01-01

    The results of field and laboratory experiments on methane consumption by tundra soils are reported. For methane concentrations ranging from below to well above ambient, moist soils are found to consume methane rapidly; in nonwaterlogged soils, equilibration with atmospheric methane is fast relative to microbial oxidation. It is concluded that lowering of the water table in tundra as a resulting from a warmer, drier climate will decrease methane fluxes and could cause these areas to provide negative feedback for atmospheric methane.

  6. Methane emissions from canopy wetlands

    NASA Astrophysics Data System (ADS)

    Martinson, G. O.; Conrad, R.

    2012-12-01

    Ground wetlands are the main natural source of methane but they fail to explain the observed amounts of methane over tropical forests. Bromeliad tanks are discrete habitats for aquatic organisms and up to several thousand of bromeliad individuals per hectare of tropical forest create a unique canopy wetland ecosystem in neotropical forests. Recently, we have discovered that canopy wetlands inhabit methanogenic archaea, emit substantial amounts of methane and may help to explain the high amounts of methane over neotropical forests. However, the pathway of methane formation and potential methane production in canopy wetlands of different tropical forest ecosystems have not yet been studied. In this study, we investigated the stable carbon isotope fractionation, methanogenic pathway and potential methane production of bromeliad tanks along an elevation gradient in neotropical forests for the first time. We sampled the bromeliad tank-substrate of 3 tank bromeliads per functional type and elevation (1000 m, 2000 m and 3000 m above the sea level). We distinguished three functional types of tank bromeliads, based on plant architecture and ecological niche preference. Functional type I-tank bromeliads are concentrated in the understory and on the ground. Functional type II and type III are concentrated in the mid and overstory. We conducted tank-substrate incubation experiments and measured CH4, CO2, 13CH4 and 13CO2 at regular time intervals during the incubation period. The methane production potential of bromeliad tanks correlated positively with tank-substrate carbon concentration and decreased with increasing canopy height and increasing elevation. The dominant pathway of methane formation in bromeliad tanks was hydrogenotrophic methanogenesis (>50%) and this dominance increased with increasing canopy height and increasing elevation. Our results provide novel insights into the pathway of methane formation in neotropical canopy wetlands and suggest that canopy height is

  7. Time-lapse analysis of methane quantity in Mary Lee group of coal seams using filter-based multiple-point geostatistical simulation

    USGS Publications Warehouse

    Karacan, C. Özgen; Olea, Ricardo A.

    2013-01-01

    The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition. Furthermore, performing filter simulations using point-wise data and TIs could be used to predict methane quantity in coal seams subjected to degasification. During the course of the study, it was shown that the material balance of gas produced by wellbores and the GIP reductions in coal seams predicted using filter simulations compared very well, showing the success of filter simulations for continuous variables in this case study. Quantitative results from filter simulations of GIP within the studied area briefly showed that GIP was reduced from an initial ∼73 Bcf (median) to ∼46 Bcf (2011), representing a 37 % decrease and varying spatially through degasification. It is forecasted that there will be an additional ∼2 Bcf reduction in methane quantity between 2011 and 2015. This study and presented results showed that the applied methodology and utilized techniques can be used to map GIP and its change within coal seams after degasification, which can further be used for ventilation design for methane control in coal mines.

  8. Dielectric Barrier Discharge Methane Conversion

    NASA Astrophysics Data System (ADS)

    Liu, Chong; Fridman, Alexander; Rabinovich, Alexander; Dobrynin, Danil

    2015-09-01

    With the large amount of nature gas discovery every year, there is an increasing interest on modification of methane. The fact that methane is gaseous makes it less economic and efficient than liquid fuel. Here we propose a new way of converting methane from gas phase to liquid phase. Dielectric barrier discharge is used to treat methane and nitrogen mixture bubbles inside of liquid fuel. Nitrogen is here to help activate methane into an excited state, then it is possible for the excited molecules to react with other liquid hydrocarbon. Gaseous methane is converted in to liquid phase when excited methane replace a hydrogen and add onto the carbon chain. In this study some preliminary experiments is done to verify this hypothesis. There is equivalent weight increases with methane and nitrogen mixture discharging in diesel when compare to only nitrogen discharging in diesel. The same experiment have also been done with gas mixture discharged in 1-methylnaphthalene. And FTIR analysis of the after treatment hydrocarbon liquid all indicates that there is an increasing in C-H bond concentration and a decreasing in phenyl ring structure.

  9. A Methane Balloon Inflation Chamber

    ERIC Educational Resources Information Center

    Czerwinski, Curtis J.; Cordes, Tanya J.; Franek, Joe

    2005-01-01

    The various equipments, procedure and hazards in constructing the device for inflating a methane balloon using a standard methane outlet in a laboratory are described. This device is fast, safe, inexpensive, and easy to use as compared to a hydrogen gas cylinder for inflating balloons.

  10. Constraining Methane Flux Estimates Using Atmospheric Observations of Methane and 1^3C in Methane

    NASA Astrophysics Data System (ADS)

    Mikaloff Fletcher, S. E.; Tans, P. P.; Miller, J. B.; Bruhwiler, L. M.

    2002-12-01

    Understanding the budget of methane is crucial to predicting climate change and managing earth's carbon reservoirs. Methane is responsible for approximately 15% of the anthropogenic greenhouse forcing and has a large impact on the oxidative capacity of Earth's atmosphere due to its reaction with hydroxyl radical. At present, many of the sources and sinks of methane are poorly understood due in part to the large spatial and temporal variability of the methane flux. Model simulations of methane mixing ratios using most process-based source estimates typically over-predict the latitudinal gradient of atmospheric methane relative to the observations; however, the specific source processes responsible for this discrepancy have not been identified definitively. The aim of this work is to use the isotopic signatures of the sources to attribute these discrepancies to a source process or group of source processes and create global and regional budget estimates that are in agreement with both the atmospheric observations of methane and 1^3C in methane. To this end, observations of isotopic ratios of 1^3C in methane and isotopic signatures of methane source processes are used in conjunction with an inverse model of the methane budget. Inverse modeling is a top-down approach which uses observations of trace gases in the atmosphere, an estimate of the spatial pattern of trace gas fluxes, and a model of atmospheric transport to estimate the sources and sinks. The atmospheric transport was represented by the TM3 three-dimensional transport model. The GLOBALVIEW 2001 methane observations were used along with flask measurements of 1^3C in methane at six of the CMDL-NOAA stations by INSTAAR. Initial results imply interesting differences from previous methane budget estimates. For example, the 1^3C isotope observations in methane call for an increase in southern hemisphere sources with a bacterial isotopic signature such as wetlands, rice paddies, termites, and ruminant animals. The

  11. Coal mine methane global review

    SciTech Connect

    2008-07-01

    This is the second edition of the Coal Mine Methane Global Overview, updated in the summer of 2008. This document contains individual, comprehensive profiles that characterize the coal and coal mine methane sectors of 33 countries - 22 methane to market partners and an additional 11 coal-producing nations. The executive summary provides summary tables that include statistics on coal reserves, coal production, methane emissions, and CMM projects activity. An International Coal Mine Methane Projects Database accompanies this overview. It contains more detailed and comprehensive information on over two hundred CMM recovery and utilization projects around the world. Project information in the database is updated regularly. This document will be updated annually. Suggestions for updates and revisions can be submitted to the Administrative Support Group and will be incorporate into the document as appropriate.

  12. Coal bed methane potential in Venezuela-The forgotten resource

    SciTech Connect

    Vasquez-Herrera, A.R.; Bereskin, S.R.; McLennan, J.D.

    1996-08-01

    In nations already possessing riches of hydrocarbons situated in conventional reservoirs, evaluation of coal-bearing sequences for potential gas is logically delayed or ignored. Nonetheless, Venezuelan coals have long been recognized as stratigraphically associated with oil accumulations, but because coalbed methane (CBM) is a relatively new worldwide phenomenon, CBM potential has not been widely assessed in the country. Two general areas contain vast accumulations of coal for potential CBM activity: (1) the Maracaibo basin, containing the Guasare (northwest), Lobatera-Santo Domingo (southwest) and Urumaco (northeast) districts; and (2) the Oficina basin in eastern Venezuela possessing abundant accumulations related to the Faja Petrolifera de Orinoco (Orinoco Oil Belt). In both basins, high volatile bituminous and lignitic coals of mostly Oligo-Miocene age are abundantly found. Older coals are also present especially in the Maracaibo area. Two factors represent powerful incentives for CBM exploitation: addition of known reserves for economic considerations, and aid in bringing heavy crude oil to the surface by additional gas lift and oil viscosity reduction. Other favorable factors important for CBM methodology include: (1) abundant coals lying above known conventional reservoir targets; (2).6 - 1% vitrinite reflectance measurements in the Orinoco Oil Belt; (3) many coals occurring above 1500 m; (4) documented mine explosions especially in the 1920s and 1930s; (5) a strong tectonic overprint to perhaps add shear fractures to already cleated coals; (6) individual coal thickness up to 12 m with averages in the .8 m range; and (7) gas shows while drilling coal-rich intervals.

  13. Oxygen-Methane Thruster

    NASA Technical Reports Server (NTRS)

    Pickens, Tim

    2012-01-01

    An oxygen-methane thruster was conceived with integrated igniter/injector capable of nominal operation on either gaseous or liquid propellants. The thruster was designed to develop 100 lbf (approximately 445 N) thrust at vacuum conditions and use oxygen and methane as propellants. This continued development included refining the design of the thruster to minimize part count and manufacturing difficulties/cost, refining the modeling tools and capabilities that support system design and analysis, demonstrating the performance of the igniter and full thruster assembly with both gaseous and liquid propellants, and acquiring data from this testing in order to verify the design and operational parameters of the thruster. Thruster testing was conducted with gaseous propellants used for the igniter and thruster. The thruster was demonstrated to work with all types of propellant conditions, and provided the desired performance. Both the thruster and igniter were tested, as well as gaseous propellants, and found to provide the desired performance using the various propellant conditions. The engine also served as an injector testbed for MSFC-designed refractory combustion chambers made of rhenium.

  14. Making methane visible

    NASA Astrophysics Data System (ADS)

    Gålfalk, Magnus; Olofsson, Göran; Crill, Patrick; Bastviken, David

    2016-04-01

    Methane (CH4) is one of the most important greenhouse gases, and an important energy carrier in biogas and natural gas. Its large scale emission patterns have been unpredictable and the source and sink distributions are poorly constrained. Remote assessment of CH4 with high sensitivity at m2 spatial resolution would allow detailed mapping of near ground distribution and anthropogenic sources and sinks in landscapes but has hitherto not been possible. Here we show that CH4 gradients can be imaged on methane imaging will include a lake, barn, sewage sludge deposit, waste incineration plant, and controlled gas releases. We will also present successful simultaneous imaging of another important greenhouse gas, nitrous oxide, with the same instrument.

  15. Search for interstellar methane

    NASA Technical Reports Server (NTRS)

    Knacke, R. F.; Kim, Y. H.; Noll, K. S.; Geballe, T. R.

    1990-01-01

    Researchers searched for interstellar methane in the spectra of infrared sources embedded in molecular clouds. New observations of several lines of the P and R branches of the nu 3 band of CH4 near 3.3 microns give column densities in the range N less than 1(-2) times 10 to the minus 16th power cm(-2). Resulting abundance ratios are (CH4)/(CO) less than 3.3 times 10 to the minus 2nd power toward GL961 in NGC 2244 and less than 2.4 times 10 to the minus 3rd power toward GL989 in the NGC 2264 molecular cloud. The limits, and those determined in earlier observations of BN in Orion and GL490, suggest that there is little methane in molecular clouds. The result agrees with predictions of chemical models. Exceptions could occur in clouds where oxygen may be depleted, for example by H2O freezing on grains. The present observations probably did not sample such regions.

  16. Hydroxylation of methane through component interactions in soluble methane monooxygenases.

    PubMed

    Lee, Seung Jae

    2016-04-01

    Methane hydroxylation through methane monooxygenases (MMOs) is a key aspect due to their control of the carbon cycle in the ecology system and recent applications of methane gas in the field of bioenergy and bioremediation. Methanotropic bacteria perform a specific microbial conversion from methane, one of the most stable carbon compounds, to methanol through elaborate mechanisms. MMOs express particulate methane monooxygenase (pMMO) in most strains and soluble methane monooxygenase (sMMO) under copper-limited conditions. The mechanisms of MMO have been widely studied from sMMO belonging to the bacterial multicomponent monooxygenase (BMM) superfamily. This enzyme has diiron active sites where different types of hydrocarbons are oxidized through orchestrated hydroxylase, regulatory and reductase components for precise control of hydrocarbons, oxygen, protons, and electrons. Recent advances in biophysical studies, including structural and enzymatic achievements for sMMO, have explained component interactions, substrate pathways, and intermediates of sMMO. In this account, oxidation of methane in sMMO is discussed with recent progress that is critical for understanding the microbial applications of C-H activation in one-carbon substrates.

  17. Groundwater flow associated with coalbed gas production, Ferron Sandstone, east-central Utah

    USGS Publications Warehouse

    Anna, L.O.

    2003-01-01

    The flow and distribution of water associated with coalbed gas production in the Ferron Sandstone was characterized utilizing a discrete fracture network model and a porous media model. A discrete fracture network model calculated fluid flux through volumes of various scales to determine scale effects, directional bulk permeability, and connectivity. The mean directional permeabilities varied by less than a factor of 6, with the northwest-southeast direction (face cleat direction) as the most conductive. Northwest southeast directed hydrofracture simulations increased permeability in all directions except the northeast-southwest, although the permeability increase was not more than a factor of 3. Cluster analysis showed that the simulated cleat network was very well connected at all simulated scales. For thick coals, the entire cleat network formed one compartment, whereas thin coals formed several compartments. Convex hulls of the compartments confirmed that the directional bulk permeability was nearly isotropic. Volumetric calculations of the Ferron coal indicated that all the water produced to date can be accounted for from the coal cleat porosity system and does not depend on contributions of water from contiguous units.Flow paths, determined from porous media modeling from recharge to discharge, indicate that the three coalbed gas (CBG) fields assessed in this study could have different groundwater chemical compositions as confirmed by geochemical data. Simulated water production from 185 wells from 1993 to 1998 showed that in 1998 the maximum head drawdown from the Drunkards Wash field was more than 365 m, and the cone of depression extended to within a short distance of the Ferron outcrop. Maximum drawdown in the Helper field was 120 m, and the maximum drawdown in the Buzzards Bench field was just over 60 m. The cone of depression for the Helper field was half the size of the Drunkards Wash field, and the cone of depression for the Buzzards Bench field was

  18. Methane Hydrates: Chapter 8

    USGS Publications Warehouse

    Boswell, Ray; Yamamoto, Koji; Lee, Sung-Rock; Collett, Timothy S.; Kumar, Pushpendra; Dallimore, Scott

    2008-01-01

    Gas hydrate is a solid, naturally occurring substance consisting predominantly of methane gas and water. Recent scientific drilling programs in Japan, Canada, the United States, Korea and India have demonstrated that gas hydrate occurs broadly and in a variety of forms in shallow sediments of the outer continental shelves and in Arctic regions. Field, laboratory and numerical modelling studies conducted to date indicate that gas can be extracted from gas hydrates with existing production technologies, particularly for those deposits in which the gas hydrate exists as pore-filling grains at high saturation in sand-rich reservoirs. A series of regional resource assessments indicate that substantial volumes of gas hydrate likely exist in sand-rich deposits. Recent field programs in Japan, Canada and in the United States have demonstrated the technical viability of methane extraction from gas-hydrate-bearing sand reservoirs and have investigated a range of potential production scenarios. At present, basic reservoir depressurisation shows the greatest promise and can be conducted using primarily standard industry equipment and procedures. Depressurisation is expected to be the foundation of future production systems; additional processes, such as thermal stimulation, mechanical stimulation and chemical injection, will likely also be integrated as dictated by local geological and other conditions. An innovative carbon dioxide and methane swapping technology is also being studied as a method to produce gas from select gas hydrate deposits. In addition, substantial additional volumes of gas hydrate have been found in dense arrays of grain-displacing veins and nodules in fine-grained, clay-dominated sediments; however, to date, no field tests, and very limited numerical modelling, have been conducted with regard to the production potential of such accumulations. Work remains to further refine: (1) the marine resource volumes within potential accumulations that can be

  19. Archaebacterial Fuel Production: Methane from Biomass.

    ERIC Educational Resources Information Center

    Lennox, John E.; And Others

    1983-01-01

    Discusses microbial production of methane from biomass. Topics include methogens (bacteria producing methane), ecology of methanogenesis, methanogenesis in ruminant/nonruminant and other environments, role of methanogenesis in nature, and methane production in sewage treatment plants. Also discusses construction of methane digesters (and related…

  20. 75 FR 9886 - Methane Hydrate Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Methane... meeting. SUMMARY: This notice announces a meeting of the Methane Hydrate Advisory Committee. Federal... Methane Hydrate Advisory Committee is to provide advice on potential applications of methane hydrate...

  1. Oceanic Methane Concentrations in Three Mexican Regions

    EPA Science Inventory

    The atmospheric concentration of methane has increased significantly over the last several decades. Methane is an important greenhouse gas, and it is important to better quantify methane sources and sinks. Dissolved methane in the ocean is produced by biological and hydrothermal ...

  2. Tetraperchlorate of methane

    NASA Technical Reports Server (NTRS)

    Schack, C. J.

    1972-01-01

    The preparation of the tetraperchlorate of methane (TPM) was attempted. Displacement of halogen from carbon tetrahalides was accomplished with either CCl4 or CBr4 using the halogen perchlorates, ClOClO3, and BOClO3. Although the displacement process was successful, the generated carbon perchlorate intermediates were not isolated. Instead, these species decomposed to COCl2, CO2, and Cl2O7. The vigorous displacement reaction that often occurred required moderation. Fluorocarbon solvents and chlorine perchlorate were successfully tested for compatibility, permitting their use in these synthetic reactions. While the sought for moderating effect was obtained, the net result of the displacement of halogen from CX sub 4 substrates was the same as before. Thus only CO2, COCl2, and Cl2O7 were isolated.

  3. (Methane digester). Final report

    SciTech Connect

    Waybright, R.C.

    1981-01-01

    The purpose of the grant was to construct and operate a methane digester for dairy manure involving the latest state-of-the-art technics. The first step taken was to empty out the existing digester to evaluate its performance and to gain ideas of how to build the next digester so it would operate more efficiently. Next, the design criteria was set up in order to eliminate some problems involved with the first digester and also new ideas as to how to build the next one without a protective building and testing simplified construction technics. After this the digester construction was started with the completion date in late January. The digester was then filled and operated at different temperatures attempting to achieve the optimum operating range.

  4. Large methane reserves beneath Antarctica?

    NASA Astrophysics Data System (ADS)

    Wadham, J. L.; Tulaczyk, S. M.; Stibal, M.; Arndt, S.; Telling, J.; Lis, G.; Lawson, E. C.; Dubnick, A.; Tranter, M.; Sharp, M. J.; Anesio, A.

    2010-12-01

    Once thought to be devoid of life, the Antarctic Ice Sheet is now known to be a dynamic reservoir of metabolically active microbial cells and organic carbon. Its potential to support the degradation of organic carbon to methane, however, has not yet been evaluated. Large marine sedimentary basins beneath the ice sheet (estimated to cover up to 50% by area and contain sedimentary sequences up to 3 km thick) remain thawed during glaciation. These basins are estimated to contain ~7000 Pg of organic carbon, assuming that sedimentary basins account for 1 and 2 M km2 of the West and East Antarctic Ice Sheets respectively, the organic carbon content of overridden marine sediments is 0.5 % and the mean sediment depth is 1 km. We predict that this carbon is microbially cycled to methane under anoxic conditions beneath the ice sheet. Laboratory experimental data are consistent with this and show that organic carbon overridden by glaciers and ice sheets produces methane under anoxic conditions, and at rates similar to those observed in sub-seafloor sediments. We numerically model the accumulation of methane in Antarctic sedimentary basins and show that sediment porewaters become over-saturated with methane over >1 Myr and that typical pressure/temperature conditions favour methane hydrate formation down to between ~500m and ~1000m in the sedimentary column. We calculate conservatively that a minimum of ~70 and ~360 PgC of releasable methane (clathrate + free gas) could be produced beneath the West and East Antarctic Ice Sheets over 3 and 30 Myr of glaciation respectively, which is of a similar order of magnitude to methane present as hydrate in Arctic permafrost. The stability of this releasable methane reserve depends sensitively upon in situ pressure conditions, and hence ice thickness. We show that only modest ice sheet retreat rates (700-2000 km2 a-1) are required to stimulate out gassing of releasable methane from Antarctic sedimentary basins at rates sufficient to

  5. Phase behavior of methane haze.

    PubMed

    Signorell, R; Jetzki, M

    2007-01-01

    Methane aerosols play a fundamental role in the atmospheres of Neptune, Uranus, and Saturn's moon Titan as borne out by the recent Cassini-Huygens mission. Here we present the first study of the phase behavior of free methane aerosol particles combining collisional cooling with rapid-scan infrared spectroscopy in situ. We find fast (within minutes) phase transitions to crystalline states directly after particle formation and characteristic surface effects for nanometer-sized particles. From our results, we conclude that in atmospheric clouds solid methane particles are crystalline.

  6. Phase behavior of methane haze.

    PubMed

    Signorell, R; Jetzki, M

    2007-01-01

    Methane aerosols play a fundamental role in the atmospheres of Neptune, Uranus, and Saturn's moon Titan as borne out by the recent Cassini-Huygens mission. Here we present the first study of the phase behavior of free methane aerosol particles combining collisional cooling with rapid-scan infrared spectroscopy in situ. We find fast (within minutes) phase transitions to crystalline states directly after particle formation and characteristic surface effects for nanometer-sized particles. From our results, we conclude that in atmospheric clouds solid methane particles are crystalline. PMID:17358473

  7. Global Methane Biogeochemistry

    NASA Astrophysics Data System (ADS)

    Reeburgh, W. S.

    2003-12-01

    Methane (CH4) has been studied as an atmospheric constituent for over 200 years. A 1776 letter from Alessandro Volta to Father Campi described the first experiments on flammable "air" released by shallow sediments in Lake Maggiore (Wolfe, 1996; King, 1992). The first quantitative measurements of CH4, both involving combustion and gravimetric determination of trapped oxidation products, were reported in French by Boussingault and Boussingault, 1864 and Gautier (1901), who reported CH4 concentrations of 10 ppmv and 0.28 ppmv (seashore) and 95 ppmv (Paris), respectively. The first modern measurements of atmospheric CH4 were the infrared absorption measurements of Migeotte (1948), who estimated an atmospheric concentration of 2.0 ppmv. Development of gas chromatography and the flame ionization detector in the 1950s led to observations of vertical CH4 distributions in the troposphere and stratosphere, and to establishment of time-series sampling programs in the late 1970s. Results from these sampling programs led to suggestions that the concentration of CH4, as that of CO2, was increasing in the atmosphere. The possible role of CH4 as a greenhouse gas stimulated further research on CH4 sources and sinks. Methane has also been of interest to microbiologists, but findings from microbiology have entered the larger context of the global CH4 budget only recently.Methane is the most abundant hydrocarbon in the atmosphere. It plays important roles in atmospheric chemistry and the radiative balance of the Earth. Stratospheric oxidation of CH4 provides a means of introducing water vapor above the tropopause. Methane reacts with atomic chlorine in the stratosphere, forming HCl, a reservoir species for chlorine. Some 90% of the CH4 entering the atmosphere is oxidized through reactions initiated by the OH radical. These reactions are discussed in more detail by Wofsy (1976) and Cicerone and Oremland (1988), and are important in controlling the oxidation state of the atmosphere

  8. Mapping the hydraulic connection between a coalbed and adjacent aquifer: example of the coal-seam gas resource area, north Galilee Basin, Australia

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenjiao; Mariethoz, Gregoire; Schrank, Christoph; Cox, Malcolm; Timms, Wendy

    2016-07-01

    Coal-seam gas production requires groundwater extraction from coal-bearing formations to reduce the hydraulic pressure and improve gas recovery. In layered sedimentary basins, the coalbeds are often separated from freshwater aquifers by low-permeability aquitards. However, hydraulic connection between the coalbed and aquifers is possible due to the heterogeneity in the aquitard such as the existence of conductive faults or sandy channel deposits. For coal-seam gas extraction operations, it is desirable to identify areas in a basin where the probability of hydraulic connection between the coalbed and aquifers is low in order to avoid unnecessary loss of groundwater from aquifers and gas production problems. A connection indicator, the groundwater age indictor (GAI), is proposed, to quantify the degree of hydraulic connection. The spatial distribution of GAI can indicate the optimum positions for gas/water extraction in the coalbed. Depressurizing the coalbed at locations with a low GAI would result in little or no interaction with the aquifer when compared to the other positions. The concept of GAI is validated on synthetic cases and is then applied to the north Galilee Basin, Australia, to assess the degree of hydraulic connection between the Aramac Coal Measure and the water-bearing formations in the Great Artesian Basin, which are separated by an aquitard, the Betts Creek Beds. It is found that the GAI is higher in the western part of the basin, indicating a higher risk to depressurization of the coalbed in this region due to the strong hydraulic connection between the coalbed and the overlying aquifer.

  9. Quasielastic electron scattering from methane, methane-d4, methane-d2, ethylene, and 2-methylpropane

    NASA Astrophysics Data System (ADS)

    Cooper, G.; Christensen, E.; Hitchcock, A. P.

    2007-08-01

    Quasielastic electron scattering from gaseous species at high momentum transfer was recently reported for the first time [Cooper et al., J. Electron Spectrosc. Relat. Phenom. 155, 28 (2007)]. The first results for CH4 and CD4 were well explained by a classical electron Compton scattering picture in which the electron scatters independently from each atom rather than the molecule as a whole. However, an alternative possible interpretation in terms of nondipole molecular vibrational excitation is suggested by previously published quantum mechanical calculations on high momentum transfer electron scattering from diatomic molecules [Bonham and de Souza, J. Chem. Phys. 79, 134 (1983)]. In order to determine which of these two interpretations best fits the experimental results, we have measured the quasielastic spectra of gaseous 2-methylpropane, ethylene, methane, and two isotopically substituted methanes, CH2D2 and CD4, at a momentum transfer of ˜20a.u. (2.25keV impact energy and 100° scattering angle). The experimental spectra are found to be composed of as many peaks as there are different atomic isotopes in the molecule (two for CH4, C2H4, 2-methylpropane, and CD4 and three for CH2D2). The peak positions are predicted accurately by the independent atom electron Compton scattering model, and the relative intensities are in reasonable agreement. The experimental results thus support classical electron Compton scattering as the origin of the signal.

  10. Methane production in terrestrial arthropods

    SciTech Connect

    Hackstein, J.H.P.; Stumm, C.K. )

    1994-06-07

    The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

  11. Methane production in terrestrial arthropods.

    PubMed

    Hackstein, J H; Stumm, C K

    1994-06-01

    We have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. We show that arthropod symbionts can contribute substantially to atmospheric methane.

  12. Methane production in terrestrial arthropods.

    PubMed Central

    Hackstein, J H; Stumm, C K

    1994-01-01

    We have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. We show that arthropod symbionts can contribute substantially to atmospheric methane. Images PMID:8202505

  13. Methane emissions from MBT landfills

    SciTech Connect

    Heyer, K.-U. Hupe, K.; Stegmann, R.

    2013-09-15

    Highlights: • Compilation of methane generation potential of mechanical biological treated (MBT) municipal solid waste. • Impacts and kinetics of landfill gas production of MBT landfills, approach with differentiated half-lives. • Methane oxidation in the waste itself and in soil covers. • Estimation of methane emissions from MBT landfills in Germany. - Abstract: Within the scope of an investigation for the German Federal Environment Agency (“Umweltbundesamt”), the basics for the estimation of the methane emissions from the landfilling of mechanically and biologically treated waste (MBT) were developed. For this purpose, topical research including monitoring results regarding the gas balance at MBT landfills was evaluated. For waste treated to the required German standards, a methane formation potential of approximately 18–24 m{sup 3} CH{sub 4}/t of total dry solids may be expected. Monitoring results from MBT landfills show that a three-phase model with differentiated half-lives describes the degradation kinetics in the best way. This is due to the fact that during the first years of disposal, the anaerobic degradation processes still proceed relatively intensively. In addition in the long term (decades), a residual gas production at a low level is still to be expected. Most of the soils used in recultivation layer systems at German landfills show a relatively high methane oxidation capacity up to 5 l CH{sub 4}/(m{sup 2} h). However, measurements at MBT disposal sites indicate that the majority of the landfill gas (in particular at non-covered areas), leaves the landfill body via preferred gas emission zones (hot spots) without significant methane oxidation. Therefore, rather low methane oxidation factors are recommended for open and temporarily covered MBT landfills. Higher methane oxidation rates can be achieved when the soil/recultivation layer is adequately designed and operated. Based on the elaborated default values, the First Order Decay (FOD

  14. Methane generation from animal wastes

    SciTech Connect

    Fulton, E.L.

    1980-06-01

    The conversion of manure to biogas via anaerobic digestion is described. The effluent resulting from the conversion retains fertilizer value and is environmentally acceptable. Discussion is presented under the headings: methane formation in the digester; the Tarleton State Poultry Waste to Methane production system; operating experience at Tarleton State; economics of biogas production from poultry waste; construction cost and biogas value; energy uses; feed and waste processing; and advantages of anaerobic digestion. (DMC)

  15. Methane production in Minnesota peatlands

    SciTech Connect

    Williams, R.T.; Crawford, R.L.

    1984-06-01

    Rates of methane production in Minnesota peats were studied. Surface (10- to 25-cm) peats produced an average of 228 nmol of CH/sub 4/ per g (dry weight) per h at 25/sup 0/C and ambient pH. Methanogenesis rates generally decreased with depth in ombrotrophic peats, but on occasion were observed to rise within deeper layers of certain fen peats. Methane production was temperature dependent, increasing with increasing temperature (4 to 30/sup 0/C), except in peats from deeper layers. Maximal methanogenesis from these deeper regions occurred at 12/sup 0/C. Methane production rates were also pH dependent. Two peats with pHs of 3.8 and 4.3 had an optimum rate of methane production at pH 6.0. The addition to peat of glucose and H/sub 2/-CO/sub 2/ stimulated methanogenesis, whereas the addition of acetate inhibited methanogenesis. Cysteine-sulfide, nitrogen-phosphorus-trace metals, and vitamins-yeast extract affected methane production very little. Various gases were found to be trapped or dissolved (or both) within peatland waters. Dissolved methane increased linearly to a depth of 210 cm. The accumulation of metabolic end products produced within peat bogs appears to be an important mechanism limiting turnover in peatland environments.

  16. Optical constants of solid methane

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N.; Thompson, W. R.; Sagan, C.; Arakawa, E. T.; Bruel, C.; Judish, J. P.; Khanna, R. K.; Pollack, J. B.

    1989-01-01

    Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented of the optical constants of solid methane for the 0.4 to 2.6 micron region. K is reported for both the amorphous and the crystalline (annealed) states. Using the previously measured values of the real part of the refractive index, n, of liquid methane at 110 K n is computed for solid methane using the Lorentz-Lorentz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for condensed CH4.

  17. Is methane a new therapeutic gas?

    PubMed Central

    2012-01-01

    Background Methane is an attractive fuel. Biologically, methanogens in the colon can use carbon dioxide and hydrogen to produce methane as a by-product. It was previously considered that methane is not utilized by humans. However, in a recent study, results demonstrated that methane could exert anti-inflammatory effects in a dog small intestinal ischemia-reperfusion model. Point of view Actually, the bioactivity of methane has been investigated in gastrointestinal diseases, but the exact mechanism underlying the anti-inflammatory effects is required to be further elucidated. Methane can cross the membrane and is easy to collect due to its abundance in natural gas. Although methane is flammable, saline rich in methane can be prepared for clinical use. These seem to be good news in application of methane as a therapeutic gas. Conclusion Several problems should be resolved before its wide application in clinical practice. PMID:23009320

  18. IODP Expedition 337: Deep Coalbed Biosphere off Shimokita - Microbial processes and hydrocarbon system associated with deeply buried coalbed in the ocean

    NASA Astrophysics Data System (ADS)

    Inagaki, Fumio; Hinrichs, Kai-Uwe; Kubo, Yusuke; IODP Expedition 337 Scientists

    2016-06-01

    The Integrated Ocean Drilling Program (IODP) Expedition 337 was the first expedition dedicated to subseafloor microbiology that used riser-drilling technology with the drilling vessel Chikyu. The drilling Site C0020 is located in a forearc basin formed by the subduction of the Pacific Plate off the Shimokita Peninsula, Japan, at a water depth of 1180 m. Primary scientific objectives during Expedition 337 were to study the relationship between the deep microbial biosphere and a series of ˜ 2 km deep subseafloor coalbeds and to explore the limits of life in the deepest horizons ever probed by scientific ocean drilling. To address these scientific objectives, we penetrated a 2.466 km deep sedimentary sequence with a series of lignite layers buried around 2 km below the seafloor. The cored sediments, as well as cuttings and logging data, showed a record of dynamically changing depositional environments in the former forearc basin off the Shimokita Peninsula during the late Oligocene and Miocene, ranging from warm-temperate coastal backswamps to a cool water continental shelf. The occurrence of small microbial populations and their methanogenic activity were confirmed down to the bottom of the hole by microbiological and biogeochemical analyses. The factors controlling the size and viability of ultra-deep microbial communities in those warm sedimentary habitats could be the increase in demand of energy and water expended on the enzymatic repair of biomolecules as a function of the burial depth. Expedition 337 provided a test ground for the use of riser-drilling technology to address geobiological and biogeochemical objectives and was therefore a crucial step toward the next phase of deep scientific ocean drilling.

  19. Making methane visible

    NASA Astrophysics Data System (ADS)

    Gålfalk, Magnus; Olofsson, Göran; Crill, Patrick; Bastviken, David

    2016-04-01

    Methane (CH4) is one of the most important greenhouse gases, and an important energy carrier in biogas and natural gas. Its large-scale emission patterns have been unpredictable and the source and sink distributions are poorly constrained. Remote assessment of CH4 with high sensitivity at a m2 spatial resolution would allow detailed mapping of the near-ground distribution and anthropogenic sources in landscapes but has hitherto not been possible. Here we show that CH4 gradients can be imaged on the

  20. Methane monooxygenase: functionalizing methane at iron and copper.

    PubMed

    Sazinsky, Matthew H; Lippard, Stephen J

    2015-01-01

    Methane monooxygenases (MMOs) catalyze the conversion of methane to methanol as the first committed step in the assimilation of this hydrocarbon into biomass and energy by methanotrophs, thus playing a significant role in the biogeochemistry of this potent greenhouse gas. Two distinct enzymes, a copper-dependent membrane protein, particulate methane monooxygenase (pMMO), and an iron-dependent cytosolic protein, soluble methane monooxygenase (sMMO), carry out this transformation using large protein scaffolds that help to facilitate the timely transport of hydrocarbon, O₂, proton, and electron substrates to buried dimetallic active sites. For both enzymes, reaction of the reduced metal centers with O₂leads to intermediates that activate the relatively inert C-H bonds of hydrocarbons to yield oxidized products. Among synthetic and biological catalysts, MMOs are unique because they are the only ones known to hydroxylate methane at ambient temperatures. As a need for new industrial catalysts and green chemical transformations increases, understanding how the different MMO metal centers efficiently accomplish this challenging chemistry has become the focus of intense study. This chapter examines current understanding of the sMMO and pMMO protein structures, their methods for substrate channeling, and mechanisms for the dimetallic activation of O₂and C-H bonds. PMID:25707469

  1. Methane production from steam-exploded bamboo.

    PubMed

    Kobayashi, Fumihisa; Take, Harumi; Asada, Chikako; Nakamura, Yoshitoshi

    2004-01-01

    To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo.

  2. Methane Emission from Tropical Rivers

    NASA Astrophysics Data System (ADS)

    Sawakuchi, H. O.; Rasera, M. F. F. L.; Krusche, A. V.; Ballester, M. V. R.

    2012-04-01

    Inland water is already known as an important source of methane to atmosphere. Methane is produced in anaerobic environments usually find in lakes and floodplain bottom sediment. It is the main reason that almost all information regarding methane flux come from this environments. However, while floodplain dries during low water season reducing methanogenesis, rivers keep the capacity to emit methane throughout the year. Here we present preliminary results of CH4 flux measurements done in 6 large tropical rivers within the Amazon basin. We measured 17 areas using floating chamber during dry (low water) season, between September and November of 2011, in Amazon river mainstem, Araguaia, Xingu, Tapajós, Madeira, and Negro Rivers. Measured fluxes of all rivers ranged from 59.3 to 2974.4 mmol m-2 yr-1. Geomorphologic structure of channels is one important factor that contributes to this high heterogeneity due to development of low flow velocity depositional settings allowing formation of anoxic zones in rivers. Hydraulic and sediment barriers in the confluence of river channels promote the generation of natural dams which function as a trap for the suspension load favoring the deposition of organic rich muds. This kind of environment is very different from common river channels and has a stronger potential of methane emission. Average values of our flux measurements for this two river environments show that depositional areas can have much higher fluxes than the main channel, 1089.6 and 163.1 mmol m-2 yr-1, respectively. Hence, CH4 flux from these depositional zones is similar to some tropical floodplain lakes and reservoirs. Although the low flux from channel, the area covered by water is very large resulting in a significant contribution to the regional methane emission to the atmosphere. Moreover, mapping the area of these depositional river zones will give us a better idea of the magnitude of methane flux from tropical rivers.

  3. Characterization of Methane Degradation and Methane-Degrading Microbes in Alaska Coastal Water

    SciTech Connect

    Kirchman, David L.

    2012-03-29

    The net flux of methane from methane hydrates and other sources to the atmosphere depends on methane degradation as well as methane production and release from geological sources. The goal of this project was to examine methane-degrading archaea and organic carbon oxidizing bacteria in methane-rich and methane-poor sediments of the Beaufort Sea, Alaska. The Beaufort Sea system was sampled as part of a multi-disciplinary expedition (Methane in the Arctic Shelf or MIDAS) in September 2009. Microbial communities were examined by quantitative PCR analyses of 16S rRNA genes and key methane degradation genes (pmoA and mcrA involved in aerobic and anaerobic methane degradation, respectively), tag pyrosequencing of 16S rRNA genes to determine the taxonomic make up of microbes in these sediments, and sequencing of all microbial genes (metagenomes ). The taxonomic and functional make-up of the microbial communities varied with methane concentrations, with some data suggesting higher abundances of potential methane-oxidizing archaea in methane-rich sediments. Sequence analysis of PCR amplicons revealed that most of the mcrA genes were from the ANME-2 group of methane oxidizers. According to metagenomic data, genes involved in methane degradation and other degradation pathways changed with sediment depth along with sulfate and methane concentrations. Most importantly, sulfate reduction genes decreased with depth while the anaerobic methane degradation gene (mcrA) increased along with methane concentrations. The number of potential methane degradation genes (mcrA) was low and inconsistent with other data indicating the large impact of methane on these sediments. The data can be reconciled if a small number of potential methane-oxidizing archaea mediates a large flux of carbon in these sediments. Our study is the first to report metagenomic data from sediments dominated by ANME-2 archaea and is one of the few to examine the entire microbial assemblage potentially involved in

  4. Anaerobic Methane Oxidation: Occurrence and Ecology

    PubMed Central

    Zehnder, Alexander J. B.; Brock, Thomas D.

    1980-01-01

    Anoxic sediments and digested sewage sludge anaerobically oxidized methane to carbon dioxide while producing methane. This strictly anaerobic process showed a temperature optimum between 25 and 37°C, indicating an active microbial participation in this reaction. Methane oxidation in these anaerobic habitats was inhibited by oxygen. The rate of the oxidation followed the rate of methane production. The observed anoxic methane oxidation in Lake Mendota and digested sewage sludge was more sensitive to 2-bromoethanesulfonic acid than the simultaneous methane formation. Sulfate diminished methane formation as well as methane oxidation. However, in the presence of iron and sulfate the ratio of methane oxidized to methane formed increased markedly. Manganese dioxide and higher partial pressures of methane also stimulated the oxidation. The rate of methane oxidation in untreated samples was approximately 2% of the CH4 production rate in Lake Mendota sediments and 8% of that in digested sludge. This percentage could be increased up to 90% in sludge in the presence of 10 mM ferrous sulfate and at a partial pressure of methane of 20 atm (2,027 kPa). PMID:16345488

  5. Geologic history of natural coal-bed fires, Powder River basin, USA

    USGS Publications Warehouse

    Heffern, E.L.; Coates, D.A.

    2004-01-01

    Coal-bed fires ignited by natural processes have baked and fused overlying sediments to form clinker, a hard red or varicolored rock, through much of the northern Great Plains of the United States (USA). The gently dipping coal beds in the region burn when regional downwasting brings them above the local water table. The resulting clinker forms a rim along the exposed edge of the coal bed in an ongoing process through geologic time. The resistant clinker is left capping buttes and ridges after the softer unbaked strata erode away. Clinker outcrops cover more than 4100 km2 in the Powder River basin (PRB), which lies in Wyoming (WY) and Montana (MT). The clinker in place records tens of billions of tons of coal that have burned, releasing gases into the atmosphere. The amount of clinker that has eroded away was at least an order of magnitude greater than the clinker that remains in place. Fission-track and uranium-thorium/ helium ages of detrital zircon crystals in clinker, and paleomagnetic ages of clinker, show that coal beds have burned naturally during at least the past 4 million years (Ma). The oldest in-place clinker that has been dated, collected from a high, isolated, clinker-capped ridge, has a fission track age of 2.8??0.6 Ma. Evidence of erosion and downcutting is also preserved by clinker clasts in gravel terraces. One clinker boulder in a terrace 360 m above the Yellowstone River has a fission track age of 4.0??0.7 Ma. Coal-bed fires are caused by lightning, wildfires, spontaneous combustion, or human activity on coal outcrops and in mines. Miners, government agencies, and ranchers have extinguished thousands of coal bed fires, but natural ignition continues where fresh coal has access to air. At any given time, hundreds of fires, mostly small, are burning. In the Powder River basin, the total amount of coal burned by natural fires in the last 2 Ma is one to two orders of magnitude greater than the total amount of coal removed by mining in the past

  6. 46 CFR 154.703 - Methane (LNG).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG)...

  7. Biogeochemistry: Rebalancing the global methane budget

    NASA Astrophysics Data System (ADS)

    Allen, Grant

    2016-10-01

    A database of the carbon-isotope 'fingerprints' of methane has been used to constrain the contributions of different sources to the global methane budget. The surprising results have implications for climate prediction. See Letter p.88

  8. Hello, Water -- Good-bye, Methane

    NASA Video Gallery

    An animation shows carbon, hydrogen and oxygen atoms. Two hydrogen atoms join each oxygen atom to make water, or H2O. Four hydrogen atoms join a carbon atom to make methane, or CH4. The methane the...

  9. Method for the photocatalytic conversion of methane

    DOEpatents

    Noceti, Richard P.; Taylor, Charles E.; D'Este, Joseph R.

    1998-01-01

    A method for converting methane to methanol is provided comprising subjecting the methane to visible light in the presence of a catalyst and an electron transfer agent. Another embodiment of the invention provides for a method for reacting methane and water to produce methanol and hydrogen comprising preparing a fluid containing methane, an electron transfer agent and a photolysis catalyst, and subjecting said fluid to visible light for an effective period of time.

  10. Method for the photocatalytic conversion of methane

    DOEpatents

    Noceti, R.P.; Taylor, C.E.; D`Este, J.R.

    1998-02-24

    A method for converting methane to methanol is provided comprising subjecting the methane to visible light in the presence of a catalyst and an electron transfer agent. Another embodiment of the invention provides for a method for reacting methane and water to produce methanol and hydrogen comprising preparing a fluid containing methane, an electron transfer agent and a photolysis catalyst, and subjecting said fluid to visible light for an effective period of time. 3 figs.

  11. Quantification of Methane and Ethane Emissions from the San Juan Basin

    NASA Astrophysics Data System (ADS)

    Smith, M. L.; Kort, E. A.; Karion, A.; Sweeney, C.; Gvakharia, A.

    2015-12-01

    Methane (CH4), a potent greenhouse gas, and the primary component of natural gas, is emitted from areas of high fossil fuel production and processing. Recently, persistent and large methane emissions (~0.59 Tg yr-1) from the four corners area of the United States have been identified using satellite (SCIAMACHY) observations taken over the years 2003 to 2009. These emissions appear to be the largest CH4 anomaly (positive deviation above background values) in the contiguous U.S., and exceed bottom-up inventory estimates for the area by 1.8 to 3.5 times. The majority of emissions sources expected to contribute to this anomalous CH4 signal are located in the San Juan basin of New Mexico, and include harvesting and processing of natural gas, coal, and coalbed CH4. The magnitude of CH4 emissions from the San Juan basin have not yet been directly quantified using airborne measurements. Additionally, changing fossil fuel-related activities in the basin may have altered the magnitude of CH4 emissions compared to estimates derived from 2003-2009 satellite measurements. Here, we present in-situ airborne observations of CH4 over the San Juan basin, which allow tight quantification of CH4 fluxes using the mass balance method. Observations over the basin were taken for multiple wind directions on multiple days in April, 2015 to obtain a robust estimate of CH4 emissions. The flux of ethane (C2H6), the second most abundant component of natural gas and a tracer species indicative of fossil-derived CH4, was also quantified. Substantial C2H6 emissions may affect regional air quality and chemistry through its influence on tropospheric ozone production.

  12. Potential methane reservoirs beneath Antarctica.

    PubMed

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.

  13. Potential methane reservoirs beneath Antarctica.

    PubMed

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387

  14. Optical constants of solid methane

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N.; Thompson, W. R.; Sagan, C.; Arakawa, E. T.; Bruel, C.; Judish, J. P.; Khanna, R. K.; Pollack, J. B.

    1990-01-01

    Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented on the optical constants of solid methane for the 0.4 to 2.6 micrometer region. Deposition onto a substrate at 10 K produces glassy (semi-amorphous) material. Annealing this material at approximately 33 K for approximately 1 hour results in a crystalline material as seen by sharper, more structured bands and negligible background extinction due to scattering. The constant k is reported for both the amorphous and the crystalline (annealed) states. Typical values (at absorption maxima) are in the .001 to .0001 range. Below lambda = 1.1 micrometers the bands are too weak to be detected by transmission through the films less than or equal to 215 micrometers in thickness, employed in the studies to date. Using previously measured values of the real part of the refractive index, n, of liquid methane at 110 K, n is computed for solid methane using the Lorentz-Lorenz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for

  15. Is there methane on Mars?

    NASA Astrophysics Data System (ADS)

    Zahnle, Kevin; Freedman, Richard S.; Catling, David C.

    2011-04-01

    There have been several reports of methane on Mars at the 10-60 ppbv level. Most suggest that methane is both seasonally and latitudinally variable. Here we review why variable methane on Mars is physically and chemically implausible, and then we critically review the published reports. There is no known mechanism for destroying methane chemically on Mars. But if there is one, methane oxidation would deplete the O 2 in Mars's atmosphere in less than 10,000 years unless balanced by an equally large unknown source of oxidizing power. Physical sequestration does not raise these questions, but adsorption in the regolith or condensation in clathrates ignore competition for adsorption sites or are inconsistent with clathrate stability, respectively. Furthermore, any mechanism that relies on methane's van der Waals' attraction is inconsistent with the continued presence of Xe in the atmosphere at the 60 ppbv level. We then use the HITRAN database and transmission calculations to identify and characterize the absorption lines that would be present on Earth or Mars at the wavelengths of the published observations. These reveal strong competing telluric absorption that is most problematic at just those wavelengths where methane's signature seems most clearly seen from Earth. The competing telluric lines must be removed with models. The best case for martian methane was made for the 12CH 4ν3 R0 and R1 lines seen in blueshift when Mars was approaching Earth in early 2003 (Mumma, M.J., Villanueva, G.L., Novak, R.E., Hewagama, T., Bonev, B.P., DiSanti, M.A., Mandell, A.M., Smith, M.D. [2009]. Science 323, 1041-1045). For these the Doppler shift moves the two martian lines into near coincidence with telluric 13CH 4ν3 R1 and R2 lines that are 10-50× stronger than the inferred martian lines. By contrast, the 12CH 4ν3 R0 and R1 lines when observed in redshift do not contend with telluric 13CH 4. For these lines, Mumma et al.'s observations and analyses are consistent with an

  16. Terminating marine methane bubbles by superhydrophobic sponges.

    PubMed

    Chen, Xiao; Wu, Yuchen; Su, Bin; Wang, Jingming; Song, Yanlin; Jiang, Lei

    2012-11-14

    Marine methane bubbles are absorbed, steadily stored, and continuously transported based on the employment of superhydrophobic sponges. Antiwetting sponges are water-repellent in the atmosphere and absorb gas bubbles under water. Their capacity to store methane bubbles increases with enhanced submerged depth. Significantly, trapped methane bubbles can be continuously transported driven by differential pressure.

  17. APPROACH FOR ESTIMATING GLOBAL LANDFILL METHANE EMISSIONS

    EPA Science Inventory

    The report is an overview of available country-specific data and modeling approaches for estimating global landfill methane. Current estimates of global landfill methane indicate that landfills account for between 4 and 15% of the global methane budget. The report describes an ap...

  18. Are methane production and cattle performance related?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methane is a product of fermentation of feed in ruminant animals. Approximately 2 -12% of the gross energy consumed by cattle is released through enteric methane production. There are three primary components that contribute to the enteric methane footprint of an animal. Those components are dry ...

  19. 78 FR 37536 - Methane Hydrate Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Methane... meeting. SUMMARY: This notice announces a meeting of the Methane Hydrate Advisory Committee. The Federal... of the Methane Hydrate Advisory Committee is to provide advice on potential applications of...

  20. 40 CFR 721.4820 - Methane, bromodifluoro-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Methane, bromodifluoro-. 721.4820... Substances § 721.4820 Methane, bromodifluoro-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as methane, bromodifluoro- is subject to reporting...

  1. 30 CFR 75.342 - Methane monitors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Methane monitors. 75.342 Section 75.342 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.342 Methane monitors. (a)(1) MSHA approved methane monitors shall be installed on all face cutting machines, continuous miners, longwall...

  2. 30 CFR 75.342 - Methane monitors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Methane monitors. 75.342 Section 75.342 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.342 Methane monitors. (a)(1) MSHA approved methane monitors shall be installed on all face cutting machines, continuous miners, longwall...

  3. 40 CFR 721.4820 - Methane, bromodifluoro-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methane, bromodifluoro-. 721.4820... Substances § 721.4820 Methane, bromodifluoro-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as methane, bromodifluoro- is subject to reporting...

  4. 30 CFR 75.342 - Methane monitors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Methane monitors. 75.342 Section 75.342 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.342 Methane monitors. (a)(1) MSHA approved methane monitors shall be installed on all face cutting machines, continuous miners, longwall...

  5. 76 FR 59667 - Methane Hydrate Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Methane... Meeting. SUMMARY: This notice announces a meeting of the Methane Hydrate Advisory Committee. Federal... of the Committee: The purpose of the Methane Hydrate Advisory Committee is to provide advice...

  6. 78 FR 26337 - Methane Hydrate Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Methane... Meeting. SUMMARY: This notice announces a meeting of the Methane Hydrate Advisory Committee. The Federal... of the Methane Hydrate Advisory Committee is to provide advice on potential applications of...

  7. 30 CFR 75.342 - Methane monitors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Methane monitors. 75.342 Section 75.342 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.342 Methane monitors. (a)(1) MSHA approved methane monitors shall be installed on all face cutting machines, continuous miners, longwall...

  8. Improving saline-sodic coalbed natural gas water quality using natural zeolites.

    PubMed

    Ganjegunte, Girisha K; Vance, George F; Gregory, Robert W; Urynowicz, Michael A; Surdam, Ronald C

    2011-01-01

    Management of saline-sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolie zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)-rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca(2+)-rich natural clinoptilolites to remove Na+ from saline-sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity ofclinoptilolite ranged from 4.3 (4 x 6 mesh) to 7.98 g kg(-1) (14 x 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 x 8, 6 x 14, and 14 x 40 mesh) zeolites. Passing the CBNG water through Ca(2+)-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption 10 mmol 1/2 L(-1/2). Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor-quality CBNG waters.

  9. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    USGS Publications Warehouse

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  10. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate.

    PubMed

    Farag, Aïda M; Harper, David D; Skaar, Don

    2014-09-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO(3) rise to more than 1500 mg/L (also expressed as >1245 mg HCO(3) (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  11. Soil chemical changes resulting from irrigation with water co-produced with coalbed natural gas

    SciTech Connect

    Ganjegunte, G.K.; Vance, G.F.; King, L.A.

    2005-12-01

    Land application of coalbed natural gas (CBNG) co-produced water is a popular management option within northwestern Powder River Basin (PRB) of Wyoming. This study evaluated the impacts of land application of CBNG waters on soil chemical properties at five sites. Soil samples were collected from different depths (0-5, 5-15, 15-30, 30-60, 60-90, and 90-120 cm) from sites that were irrigated with CBNG water for 2 to 3 yr and control sites. Chemical properties of CBNG water used for irrigation on the study sites indicate that electrical conductivity of CBNG water (EC{sub w}) and sodium adsorption ratio of CBNG water (SAR{sub w}) values were greater than those recommended for irrigation use on the soils at the study sites. Soil chemical analyses indicated that electrical conductivity of soil saturated paste extracts (ECe) and sodium adsorption ratio of soil saturated paste extracts (SAR(e)) values for irrigated sites were significantly greater (P < 0.05) than control plots in the upper 30-cm soil depths. Mass balance calculations suggested that there has been significant buildup of Na in irrigated soils due to CBNG irrigation water as well as Na mobilization within the soil profiles. Results indicate that irrigation with CBNG water significantly impacts certain soil properties, particularly if amendments are not properly utilized. This study provides information for better understanding changes in soil properties due to land application of CBNG water.

  12. Improving saline-sodic coalbed natural gas water quality using natural zeolites.

    PubMed

    Ganjegunte, Girisha K; Vance, George F; Gregory, Robert W; Urynowicz, Michael A; Surdam, Ronald C

    2011-01-01

    Management of saline-sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolie zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)-rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca(2+)-rich natural clinoptilolites to remove Na+ from saline-sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity ofclinoptilolite ranged from 4.3 (4 x 6 mesh) to 7.98 g kg(-1) (14 x 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 x 8, 6 x 14, and 14 x 40 mesh) zeolites. Passing the CBNG water through Ca(2+)-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption 10 mmol 1/2 L(-1/2). Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor-quality CBNG waters. PMID:21488493

  13. The effect of elevated methane pressure on methane hydrate dissociation

    USGS Publications Warehouse

    Circone, S.; Stern, L.A.; Kirby, S.H.

    2004-01-01

    Methane hydrate, equilibrated at P, T conditions within the hydrate stability field, was rapidly depressurized to 1.0 or 2.0 MPa and maintained at isobaric conditions outside its stability field, while the extent and rate of hydrate dissociation was measured at fixed, externally maintained temperatures between 250 and 288 K. The dissociation rate decreases with increasing pressure at a given temperature. Dissociation rates at 1.0 MPa parallel the complex, reproducible T-dependence previously observed between 250 and 272 K at 0.1 MPa. The lowest rates were observed near 268 K, such that >50% of the sample can persist for more than two weeks at 0.1 MPa to more than a month at 1 and 2 MPa. Varying the pressure stepwise in a single experiment increased or decreased the dissociation rate in proportion to the rates observed in the isobaric experiments, similar to the rate reversibility previously observed with stepwise changes in temperature at 0.1 MPa. At fixed P, T conditions, the rate of methane hydrate dissociation decreases monotonically with time, never achieving a steady rate. The relationship between time (t) and the extent of hydrate dissociation is empirically described by: Evolved gas (%) = A??tB where the pre-exponential term A ranges from 0 to 16% s-B and the exponent B is generally <1. Based on fits of the dissociation results to Equation 1 for the full range of temperatures (204 to 289 K) and pressures (0.1 to 2.0 MPa) investigated, the derived parameters can be used to predict the methane evolution curves for pure, porous methane hydrate to within ??5%. The effects of sample porosity and the presence of quartz sand and seawater on methane hydrate dissociation are also described using Equation 1.

  14. Methane sources and emissions in Italy

    SciTech Connect

    Guidotti, G.R.; Castagnola, A.M.

    1994-12-31

    Methane emissions in Italy were assessed in the framework of the measures taken to follow out the commitments undertaken at the 1992 U.N. Conference for Environment and Development. Methane emissions of anthropic origin were estimated to be in the range of 1.6 to 2.3 million ton of methane per year. Some of these methane sources (natural gas production, transmission and distribution; rice paddies; managed livestock enteric fermentation and waste; solid waste landfills) are given here particular care as they mainly contribute to the total methane emission budget.

  15. Methane on Triton - Physical state and distribution

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Apt, J.

    1984-01-01

    Infrared spectrophotometric measurements of Neptune's satellite Triton obtained between 1980 and 1982 in the spectral range 0.8-2.5 microns show six individual absorption bands attributable to methane. An additional band in the Triton data is not methane. The Triton spectral data conform more closely to a laboratory spectrum of frozen methane than to a synthetic spectrum of methane gas computed for conditions of low temperature expected at the satellite. Additionally, the strength of the bands vary with Triton's orbital position. The data thus suggest that methane in the ice phase is mostly responsible for the bands in Triton's spectrum, and that the ice is distributed nonuniformly around the satellite's surface.

  16. Methane Dynamics in Flooded Lands

    EPA Science Inventory

    Methane (CH4) is the second most important anthropogenic greenhouse gas with a heat trapping capacity 34 times greater than that of carbon dioxide on a100 year time scale. Known anthropogenic CH4 sources include livestock production, rice agriculture, landfills, and natural gas m...

  17. Bis(2-chloroethoxy)methane

    Integrated Risk Information System (IRIS)

    Bis ( 2 - chloroethoxy ) methane ; CASRN 111 - 91 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  18. Methane flux from Minnesota peatlands

    SciTech Connect

    Crill, P.M.; Bartlett, K.B.; Harriss, R.C.; Gorham, E.; Verry, E.S. )

    1988-12-01

    Northern (> 40 deg N) wetlands have been suggested as the largest natural source of methane (CH{sub 4}) to the troposphere. To refine the authors estimates of source strengths from this region and to investigate climatic controls on the process, fluxes were measured from a variety of Minnesota peatlands during May, June, and August 1986. Late spring and summer fluxes ranged from 11 to 866 mg CH{sub 4}/sq/m/day, averaging 207 mg CH{sub 4} sq/m/day overall. At Marcell Forest, forested bogs and fen sites had lower fluxes than open bogs. In the Red Lake peatland, circumneutral fens, with standing water above the peat surface, produced more methane than acid bog sites in which the water table was beneath the moss surface. Peat temperature was an important control. Methane flux increased in response to increasing soil temperature. It is estimated that the methane flux from all peatlands north of 40 deg may be on the order of 70 to 90 Tg/yr though estimates of this sort are plagued by uncertainties in the areal extent of peatlands, length of the CH{sub 4} producing season, and the spatial and temporal variability of the flux. 60 refs., 7 figs., 5 tabs.

  19. Methane production by attached film

    DOEpatents

    Jewell, William J.

    1981-01-01

    A method for purifying wastewater of biodegradable organics by converting the organics to methane and carbon dioxide gases is disclosed, characterized by the use of an anaerobic attached film expanded bed reactor for the reaction process. Dilute organic waste material is initially seeded with a heterogeneous anaerobic bacteria population including a methane-producing bacteria. The seeded organic waste material is introduced into the bottom of the expanded bed reactor which includes a particulate support media coated with a polysaccharide film. A low-velocity upward flow of the organic waste material is established through the bed during which the attached bacterial film reacts with the organic material to produce methane and carbon dioxide gases, purified water, and a small amount of residual effluent material. The residual effluent material is filtered by the film as it flows upwardly through the reactor bed. In a preferred embodiment, partially treated effluent material is recycled from the top of the bed to the bottom of the bed for further treatment. The methane and carbon dioxide gases are then separated from the residual effluent material and purified water.

  20. Methane storage in molecular nanostructures

    NASA Astrophysics Data System (ADS)

    Adisa, Olumide O.; Cox, Barry J.; Hill, James M.

    2012-05-01

    We survey various molecular structures which have been proposed as possible nanocontainers for methane storage. These are molecular structures that have been investigated through either experiments, molecular dynamics simulations or mathematical modelling. Computational simulation and mathematical modelling play an important role in predicting and verifying experimental outcomes, but both have their limitations. Even though recent advances have greatly improved computations, due to the large number of atoms and force field calculations involved, computational simulations can still be time consuming as compared to an instantaneous mathematical modelling approach. On the other hand, underlying an ideal mathematical model, there are many assumptions and approximations, but such modelling often reveals the key physical parameters and optimal configurations. Here, we review methane adsorption for three conventional nanostructures, namely graphite, single and multi-walled carbon nanotubes, and nanotube bundles (including interstitial and groove sites), and we survey methane adsorption in other molecular structures including metal organic frameworks. We also include an examination of minimum binding energies, equilibrium distances, gravimetric and volumetric uptakes, volume available for adsorption, as well as the effects of temperature and pressure on the adsorption of methane onto these molecular structures.

  1. Methane on the greenhouse agenda

    NASA Technical Reports Server (NTRS)

    Hogan, Kathleen B.; Hoffman, John S.; Thompson, Anne M.

    1991-01-01

    Options for reducing methane emissions, which could have a significant effect on global warming, are addressed. Emissions from landfills, coal mining, oil and natural gas systems, ruminants, animal wastes and wastewater, rice cultivation, and biomass burning are considered. Methods for implementing these emission reductions are discussed.

  2. Ductile flow of methane hydrate

    USGS Publications Warehouse

    Durham, W.B.; Stern, L.A.; Kirby, S.H.

    2003-01-01

    Compressional creep tests (i.e., constant applied stress) conducted on pure, polycrystalline methane hydrate over the temperature range 260-287 K and confining pressures of 50-100 MPa show this material to be extraordinarily strong compared to other icy compounds. The contrast with hexagonal water ice, sometimes used as a proxy for gas hydrate properties, is impressive: over the thermal range where both are solid, methane hydrate is as much as 40 times stronger than ice at a given strain rate. The specific mechanical response of naturally occurring methane hydrate in sediments to environmental changes is expected to be dependent on the distribution of the hydrate phase within the formation - whether arranged structurally between and (or) cementing sediments grains versus passively in pore space within a sediment framework. If hydrate is in the former mode, the very high strength of methane hydrate implies a significantly greater strain-energy release upon decomposition and subsequent failure of hydrate-cemented formations than previously expected.

  3. Methane generation from waste materials

    DOEpatents

    Samani, Zohrab A.; Hanson, Adrian T.; Macias-Corral, Maritza

    2010-03-23

    An organic solid waste digester for producing methane from solid waste, the digester comprising a reactor vessel for holding solid waste, a sprinkler system for distributing water, bacteria, and nutrients over and through the solid waste, and a drainage system for capturing leachate that is then recirculated through the sprinkler system.

  4. Insights into Methane Formation Temperatures, Biogenic Methanogenesis, and Natural Methane Emissions from Clumped Isotopes

    NASA Astrophysics Data System (ADS)

    Douglas, P. M.; Stolper, D. A.; Walter Anthony, K. M.; Dallimore, S.; Paull, C. K.; Wik, M.; Crill, P. M.; Winterdahl, M.; Smith, D. A.; Luhmann, A. J.; Ding, K.; Seyfried, W. E., Jr.; Eiler, J. M.; Ponton, C.; Sessions, A. L.

    2015-12-01

    Multiply substituted isotopologues of methane are a valuable new tool for characterizing and understanding the source of methane in different Earth environments. Here we present methane clumped isotope results from natural gas wells, hydrothermal vents, marine and lacustrine methane seeps, and culture experiments. We observe a wide range of formation temperatures for thermogenic methane. Methane samples from low-maturity reservoirs indicate formation temperatures between 102-144° C, high-maturity conventional and shale gasses indicate temperatures between 158-246 °C, and thermogenic coal gases indicate temperatures between 174-267 °C. Methane formation temperatures generally correlate positively with δ13C, and negatively with gas wetness indices. Methane samples from a set of marine hydrothermal vents indicate a formation temperature of 290-350 °C. Methane sampled from subsurface and marine biogenic sources typically indicate temperatures consistent with the formation environment (0-64° C). In contrast, freshwater biogenic methane samples, and cultures of hydrogenotrophic and methylotrophic methanogens, express low levels of isotopic clumping inconsistent with their formation temperature. These data and complementary models suggest that kinetic isotope effects, likely modulated by rates and pathways of methanogenesis, affect biogenic methane in cultures and freshwater environments. Alternatively, non-equilibrium signatures may result from mixing of methane with widely differing δD and δ13C values. Analyses of biogenic methane emissions from lakes indicate a correlation between methane flux and non-equilibrium clumped isotope fractionations in a given lake. Results from large methane seeps in Alaskan lakes confirm that some seeps emit thermogenic methane, but also indicate that other seeps emit subsurface biogenic methane or variable mixtures of biogenic and thermogenic methane. These results point to diverse sources for large Arctic methane seeps.

  5. Understanding the Recent Methane Budget

    NASA Astrophysics Data System (ADS)

    Bruhwiler, L.; Dlugokencky, E. J.; Masarie, K.

    2010-12-01

    Anthropogenic sources are thought to account for roughly 2/3 of the global atmospheric methane budget, with natural sources making up the other 1/3. Emissions from wetlands are the largest contribution from natural sources while agriculture (rice and ruminants) and waste dominate anthropogenic emissions. Fugitive emissions from fossil fuel extraction are thought to make up about 20% of the global atmospheric methane budget. It is generally recognized that observed inter-annual variability in global network observations can be attributed to natural sources such as wetlands and biomass burning, while longer-term trends likely indicate changes in anthropogenic sources. Exceptions include an abrupt decrease in fossil fuel emissions in the early 1990s associated with political changes in the Former Soviet Union, and long-term trends in emissions from the Arctic due to a warming climate. The growth rate of global average atmospheric methane since the 1980s shows a steady decline until recent years when it started to increase again. Superimposed on these trends are episodes of higher growth rates. The cause of the recent increase is not currently well-understood, although climate-driven increases in wetland emissions likely played an important role, especially in the tropics. Recent increases in anthropogenic emissions, especially from rapidly expanding Asian economies cannot be ruled out. In addition, trends in the photochemical lifetime of methane must also be considered. In this paper we use both traditional data analysis of observations of methane and related species, and a state-of-the-art ensemble data assimilation system (CarbonTracker-CH4) to attribute methane variability and trends to anthropogenic and natural source processes. We pay particular attention to the Arctic, where some recent years have been the warmest on record, and to the tropics and the potential role of ENSO in driving variability of wetland emissions. Finally, we explore whether a signal in

  6. The regulation of methane oxidation in soil

    NASA Technical Reports Server (NTRS)

    Mancinelli, R. L.

    1995-01-01

    The atmospheric concentration of methane, a greenhouse gas, has more than doubled during the past 200 years. Consequently, identifying the factors influencing the flux of methane into the atmosphere is becoming increasingly important. Methanotrophs, microaerophilic organisms widespread in aerobic soils and sediments, oxidize methane to derive energy and carbon for biomass. In so doing, they play an important role in mitigating the flux of methane into the atmosphere. Several physico-chemical factors influence rates of methane oxidation in soil, including soil diffusivity; water potential; and levels of oxygen, methane, ammonium, nitrate, nitrite, and copper. Most of these factors exert their influence through interactions with methane monooxygenase (MMO), the enzyme that catalyzes the reaction converting methane to methanol, the first step in methane oxidation. Although biological factors such as competition and predation undoubtedly play a role in regulating the methanotroph population in soils, and thereby limit the amount of methane consumed by methanotrophs, the significance of these factors is unknown. Obtaining a better understanding of the ecology of methanotrophs will help elucidate the mechanisms that regulate soil methane oxidation.

  7. Estimation of methane emission flux at landfill surface using laser methane detector: Influence of gauge pressure.

    PubMed

    Park, Jin-Kyu; Kang, Jong-Yun; Lee, Nam-Hoon

    2016-08-01

    The aim of this study was to investigate the possibility of measuring methane emission fluxes, using surface methane concentration and gauge pressure, by analyzing the influence of gauge pressure on the methane emission flux and the surface methane concentration, as well as the correlation between the methane emission flux and surface methane concentrations. The surface methane concentration was measured using a laser methane detector. Our results show a positive linear relationship between the surface methane concentration and the methane emission flux. Furthermore, the methane emission flux showed a positive linear relationship with the gauge pressure; this implies that when the surface methane concentration and the surface gauge pressure are measured simultaneously, the methane emission flux can be calculated using Darcy's law. A decrease in the vertical permeability was observed when the gauge pressure was increased, because reducing the vertical permeability may lead to a reduced landfill gas emission to the atmosphere, and landfill gas would be accumulated inside the landfill. Finally, this method is simple and can allow for a greater number of measurements during a relatively shorter period. Thus, it provides a better representation of the significant space and time variations in methane emission fluxes. PMID:27401161

  8. Estimation of methane emission flux at landfill surface using laser methane detector: Influence of gauge pressure.

    PubMed

    Park, Jin-Kyu; Kang, Jong-Yun; Lee, Nam-Hoon

    2016-08-01

    The aim of this study was to investigate the possibility of measuring methane emission fluxes, using surface methane concentration and gauge pressure, by analyzing the influence of gauge pressure on the methane emission flux and the surface methane concentration, as well as the correlation between the methane emission flux and surface methane concentrations. The surface methane concentration was measured using a laser methane detector. Our results show a positive linear relationship between the surface methane concentration and the methane emission flux. Furthermore, the methane emission flux showed a positive linear relationship with the gauge pressure; this implies that when the surface methane concentration and the surface gauge pressure are measured simultaneously, the methane emission flux can be calculated using Darcy's law. A decrease in the vertical permeability was observed when the gauge pressure was increased, because reducing the vertical permeability may lead to a reduced landfill gas emission to the atmosphere, and landfill gas would be accumulated inside the landfill. Finally, this method is simple and can allow for a greater number of measurements during a relatively shorter period. Thus, it provides a better representation of the significant space and time variations in methane emission fluxes.

  9. Methane clathrates in the solar system.

    PubMed

    Mousis, Olivier; Chassefière, Eric; Holm, Nils G; Bouquet, Alexis; Waite, Jack Hunter; Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-Dib, Mohamad; Charlou, Jean-Luc; Rousselot, Philippe

    2015-04-01

    We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form into the building blocks of comets, icy bodies, and giant planets. Methane clathrates may play an important role in the evolution of planetary atmospheres. On Earth, the production of methane in clathrates is essentially biological, and these compounds are mostly found in permafrost regions or in the sediments of continental shelves. On Mars, methane would more likely derive from hydrothermal reactions with olivine-rich material. If they do exist, martian methane clathrates would be stable only at depth in the cryosphere and sporadically release some methane into the atmosphere via mechanisms that remain to be determined. In the case of Titan, most of its methane probably originates from the protosolar nebula, where it would have been trapped in the clathrates agglomerated by the satellite's building blocks. Methane clathrates are still believed to play an important role in the present state of Titan. Their presence is invoked in the satellite's subsurface as a means of replenishing its atmosphere with methane via outgassing episodes. The internal oceans of Enceladus and Europa also provide appropriate thermodynamic conditions that allow formation of methane clathrates. In turn, these clathrates might influence the composition of these liquid reservoirs. Finally, comets and Kuiper Belt Objects might have formed from the agglomeration of clathrates and pure ices in the nebula. The methane observed in comets would then result from the destabilization of clathrate layers in the nuclei concurrent with their approach to perihelion. Thermodynamic equilibrium calculations show that methane-rich clathrate

  10. Methane clathrates in the solar system.

    PubMed

    Mousis, Olivier; Chassefière, Eric; Holm, Nils G; Bouquet, Alexis; Waite, Jack Hunter; Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-Dib, Mohamad; Charlou, Jean-Luc; Rousselot, Philippe

    2015-04-01

    We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form into the building blocks of comets, icy bodies, and giant planets. Methane clathrates may play an important role in the evolution of planetary atmospheres. On Earth, the production of methane in clathrates is essentially biological, and these compounds are mostly found in permafrost regions or in the sediments of continental shelves. On Mars, methane would more likely derive from hydrothermal reactions with olivine-rich material. If they do exist, martian methane clathrates would be stable only at depth in the cryosphere and sporadically release some methane into the atmosphere via mechanisms that remain to be determined. In the case of Titan, most of its methane probably originates from the protosolar nebula, where it would have been trapped in the clathrates agglomerated by the satellite's building blocks. Methane clathrates are still believed to play an important role in the present state of Titan. Their presence is invoked in the satellite's subsurface as a means of replenishing its atmosphere with methane via outgassing episodes. The internal oceans of Enceladus and Europa also provide appropriate thermodynamic conditions that allow formation of methane clathrates. In turn, these clathrates might influence the composition of these liquid reservoirs. Finally, comets and Kuiper Belt Objects might have formed from the agglomeration of clathrates and pure ices in the nebula. The methane observed in comets would then result from the destabilization of clathrate layers in the nuclei concurrent with their approach to perihelion. Thermodynamic equilibrium calculations show that methane-rich clathrate

  11. Characterizing thermogenic coalbed gas from Polish coals of different ranks by hydrous pyrolysis

    USGS Publications Warehouse

    Kotarba, M.J.; Lewan, M.D.

    2004-01-01

    To provide a better characterization of origin and volume of thermogenic gas generation from coals, hydrous pyrolysis experiments were conducted at 360??C for 72 h on Polish coals ranging in rank from lignite (0.3% R r) to semi-anthracite (2.0% Rr). Under these conditions, the lignites attained a medium-volatile bituminous rank (1.5% Rr), high-volatile bituminous coals attained a low-volatile bituminous rank (1.7% Rr), and the semi-anthracite obtained an anthracite rank (4.0% R r). Hydrous pyrolysis of a coal, irrespective of rank, provides a diagnostic ??13C value for its thermogenic hydrocarbon gases. This value can be used quantitatively to interpret mixing of indigenous thermogenic gas with microbial methane or exogenous thermogenic gas from other sources. Thermogenic methane quantities range from 20 dm3/kg of lignite (0.3% Rr) to 0.35 dm3/kg of semi-anthracite (2.0% Rr). At a vitrinite reflectance of 1.7% Rr, approximately 75% of the maximum potential for a coal to generate thermogenic methane has been expended. At a vitrinite reflectance of 1.7% Rr, more than 90% of the maximum potential for a coal to generate CO2 has been expended. Assuming that these quantities of generated CO2 remain associated with a sourcing coal bed as uplift or erosion provide conditions conducive for microbial methanogenesis, the resulting quantities of microbial methane generated by complete CO2 reduction can exceed the quantities of thermogenic methane generated from the same coal bed by a factor of 2-5. ?? 2004 Elsevier Ltd. All rights reserved.

  12. Geologic Assessment of Undiscovered, Technically Recoverable Coalbed-Gas Resources in Cretaceous and Tertiary Rocks, North Slope and Adjacent State Waters, Alaska

    USGS Publications Warehouse

    Roberts, Stephen B.

    2008-01-01

    The purpose of the U.S. Geological Survey's (USGS) National Oil and Gas Assessment is to develop geology-based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the United States, focusing on the distribution, quantity, and availability of oil and natural gas resources. The USGS has completed an assessment of the undiscovered, technically recoverable coalbed-gas resources in Cretaceous and Tertiary rocks underlying the North Slope and adjacent State waters of Alaska (USGS Northern Alaska Province 5001). The province is a priority Energy Policy and Conservation Act (EPCA) province for the National Assessment because of its potential for oil and gas resources. The assessment of this province is based on geologic principles and uses the total petroleum system concept. The geologic elements of a total petroleum system include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (stratigraphy, sedimentology, petrophysical properties), and hydrocarbon traps (trap formation and timing). In the Northern Alaska Province, the USGS used this geologic framework to define one composite coalbed gas total petroleum system and three coalbed gas assessment units within the petroleum system, and quantitatively estimated the undiscovered coalbed-gas resources within each assessment unit.

  13. Turbulent burning rates of methane and methane-hydrogen mixtures

    SciTech Connect

    Fairweather, M.; Ormsby, M.P.; Sheppard, C.G.W.; Woolley, R.

    2009-04-15

    Methane and methane-hydrogen (10%, 20% and 50% hydrogen by volume) mixtures have been ignited in a fan stirred bomb in turbulence and filmed using high speed cine schlieren imaging. Measurements were performed at 0.1 MPa (absolute) and 360 K. A turbulent burning velocity was determined for a range of turbulence velocities and equivalence ratios. Experimental laminar burning velocities and Markstein numbers were also derived. For all fuels the turbulent burning velocity increased with turbulence velocity. The addition of hydrogen generally resulted in increased turbulent and laminar burning velocity and decreased Markstein number. Those flames that were less sensitive to stretch (lower Markstein number) burned faster under turbulent conditions, especially as the turbulence levels were increased, compared to stretch-sensitive (high Markstein number) flames. (author)

  14. The Methane to Markets Coal Mine Methane Subcommittee meeting

    SciTech Connect

    2008-07-01

    The presentations (overheads/viewgraphs) include: a report from the Administrative Support Group; strategy updates from Australia, India, Italy, Mexico, Nigeria, Poland and the USA; coal mine methane update and IEA's strategy and activities; the power of VAM - technology application update; the emissions trading market; the voluntary emissions reduction market - creating profitable CMM projects in the USA; an Italian perspective towards a zero emission strategies; and the wrap-up and summary.

  15. Assessment of the Coal-Bed Gas Total Petroleum System in the Cook Inlet-Susitna region, south-central Alaska

    USGS Publications Warehouse

    Rouse, William A.; Houseknecht, David W.

    2012-01-01

    The Cook Inlet-Susitna region of south-central Alaska contains large quantities of gas-bearing coal of Tertiary age. The U.S. Geological Survey in 2011 completed an assessment of undiscovered, technically recoverable coal-bed gas resources underlying the Cook Inlet-Susitna region based on the total petroleum system (TPS) concept. The Cook Inlet Coal-Bed Gas TPS covers about 9,600,000 acres and comprises the Cook Inlet basin, Matanuska Valley, and Susitna lowland. The TPS contains one assessment unit (AU) that was evaluated for coal-bed gas resources between 1,000 and 6,000 feet in depth over an area of about 8,500,000 acres. Coal beds, which serve as both the source and reservoir for natural gas in the AU, were deposited during Paleocene-Pliocene time in mires associated with a large trunk-tributary fluvial system. Thickness of individual coal beds ranges from a few inches to more than 50 feet, with cumulative coal thickness of more than 800 feet in the western part of the basin. Coal rank ranges from lignite to subbituminous, with vitrinite reflectance values less than 0.6 percent throughout much of the AU. The AU is considered hypothetical because only a few wells in the Matanuska Valley have tested the coal-bed reservoirs, so the use of analog coal-bed gas production data was necessary for this assessment. In order to estimate reserves that might be added in the next 30 years, coal beds of the Upper Fort Union Formation in the Powder River Basin of Wyoming and Montana were selected as the production analog for Tertiary coal beds in the Cook Inlet-Susitna region. Upper Fort Union coal beds have similar rank (lignite to subbituminous), range of thickness, and coal-quality characteristics as coal beds of the Tertiary Kenai Group. By use of this analog, the mean total estimate of undiscovered coal-bed gas in the Tertiary Coal-Bed Gas AU is 4.674 trillion cubic feet (TCF) of gas.

  16. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    PubMed

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  17. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    PubMed

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  18. The origin and fate of arsenic in coalbed natural gas-produced water ponds.

    PubMed

    Sowder, J T; Kelleners, T J; Reddy, K J

    2010-01-01

    Coalbed natural gas (CBNG)-produced water contains small amounts of trace metals that can accumulate over time in produced water retention ponds. Within the Powder River Basin (PRB) of Wyoming, high concentrations of trace metals in pond water and their effect on shallow groundwater are potential concerns. A pond with a maximum As concentration of 146 microg L(-1) was studied in detail to determine the potential for groundwater pollution and to explain the cause for the high concentration of As. Infiltration characteristics, subsurface hydrology, our fall and pond water quality, isotope signatures, and trace metal balances were examined to assess the hydrology and geochemistry of the pond. The results indicated minimum or no infiltration of pond water and no measurable contamination of the shallow groundwater. The high As concentrations in the pond were determined to be the result of semi-continuous inputs of CBNG-produced water with low As concentrations (0.20-0.48 microg L(-1)), exasperated by low pond volumes during drought conditions. Because of reduced infiltration and high evaporation rates, As became concentrated over time. Reduced infiltration was most likely caused by the high sodium concentration and high sodium adsorption ratio of the CBNG-produced water, which disrupt soil structure. The findings for the pond and the techniques used may serve as a template for future impact assessments of other CBNG-produced water ponds and are relevant for the approximately 4000 ponds currently permitted in the PRB and for future ponds. Further studies are recommended in the use of playa landforms to store marginal-quality produced water. PMID:21043266

  19. Passive remediation of coalbed natural gas co-produced water using zeolite.

    PubMed

    Belbase, Shashidhar; Urynowicz, Michael A; Vance, George F; Dangi, Mohan B

    2013-12-15

    Coalbed natural gas (CBNG) co-produced waters can contain sodium (Na(+)) concentrations that may be environmentally detrimental if discharged to receiving bodies of water or applied to land surfaces. A field demonstration and companion laboratory studies were conducted to evaluate the use of a Bear River zeolite (BR-zeolite) for mitigating impacts associated with Na(+) in CBNG waters. Bench-scale kinetic and adsorption isotherm studies were performed to determine both the rate and extent of sodium Na(+) adsorption and assess the effects of bicarbonate (HCO3(-)) and chloride (Cl(-)) anions. Results of these studies showed that the adsorption of Na(+) on BR-zeolite followed the Langmuir adsorption model with maximum adsorption equal to 21 and 18 g Na(+)/kg zeolite with 0.0012 and 0.0006 L/mg Langmuir coefficients (KL) for sodium bicarbonate and sodium chloride, respectively. The kinetics study indicated that the sorption of Na(+) was inversely related to the size of the zeolite particles with significantly greater adsorption for smaller particles. The field demonstration evaluated the effectiveness of BR-zeolite for mitigating infiltration losses from Na(+) in CBNG waters. The field site utilized 12 open boreholes, each installed to a depth of approximately 1.8 m. Each borehole was lined with a 3.0 m long, 15 cm diameter schedule 40 PVC pipe and fitted with an automatic data logging pressure transducer for measuring water levels over time. The BR-zeolite was found to mitigate much of the deleterious effect that high sodium adsorption ratio (SAR = 27 (mol/m(3))(1/2)) CBNG co-produced water had on soil permeabilities. PMID:24211379

  20. The origin and fate of arsenic in coalbed natural gas-produced water ponds.

    PubMed

    Sowder, J T; Kelleners, T J; Reddy, K J

    2010-01-01

    Coalbed natural gas (CBNG)-produced water contains small amounts of trace metals that can accumulate over time in produced water retention ponds. Within the Powder River Basin (PRB) of Wyoming, high concentrations of trace metals in pond water and their effect on shallow groundwater are potential concerns. A pond with a maximum As concentration of 146 microg L(-1) was studied in detail to determine the potential for groundwater pollution and to explain the cause for the high concentration of As. Infiltration characteristics, subsurface hydrology, our fall and pond water quality, isotope signatures, and trace metal balances were examined to assess the hydrology and geochemistry of the pond. The results indicated minimum or no infiltration of pond water and no measurable contamination of the shallow groundwater. The high As concentrations in the pond were determined to be the result of semi-continuous inputs of CBNG-produced water with low As concentrations (0.20-0.48 microg L(-1)), exasperated by low pond volumes during drought conditions. Because of reduced infiltration and high evaporation rates, As became concentrated over time. Reduced infiltration was most likely caused by the high sodium concentration and high sodium adsorption ratio of the CBNG-produced water, which disrupt soil structure. The findings for the pond and the techniques used may serve as a template for future impact assessments of other CBNG-produced water ponds and are relevant for the approximately 4000 ponds currently permitted in the PRB and for future ponds. Further studies are recommended in the use of playa landforms to store marginal-quality produced water.

  1. Tracing coalbed natural gas-coproduced water using stable isotopes of carbon

    SciTech Connect

    Sharma, S.; Frost, C.D.

    2008-03-15

    Recovery of hydrocarbons commonly is associated with coproduction of water. This water may be put to beneficial use or may be reinjected into subsurface aquifers. In either case, it would be helpful to establish a fingerprint for that coproduced water so that it may be tracked following discharge on the surface or reintroduction to geologic reservoirs. This study explores the potential of using {delta}{sup 13}C of dissolved inorganic carbon (DIC) of coalbed natural gas (CBNG) - coproduced water as a fingerprint of its origin and to trace its fate once it is disposed on the surface. Our initial results for water samples coproduced with CBNG from the Powder River Basin show that this water has strongly positive {delta}{sup 13}C(DIC) (12 parts per thousand to 22 parts per thousand) that is readily distinguished from the negative {delta}{sup 13}C of most surface and ground water (-8 parts per thousand to -11 parts per thousand). Furthermore, the DIC concentrations in coproduced water samples are also high (more than 100 mg C/L) compared to the 20 to 50 mg C/L in ambient surface and ground water of the region. The distinctively high {delta}{sup 13}C and DIC concentrations allow us to identify surface and ground water that have incorporated CBNG-coproduced water. Accordingly, we suggest that the {delta}{sup 13}C(DIC) and DIC concentrations of water can be used for long-term monitoring of infiltration of CBNG-coproduced water into ground water and streams. Our results also show that the {delta} {sup 13}C (DIC) of CBNG-coproduced water from two different coal zones are distinct leading to the possibility of using {delta}{sup 13}C(DIC) to distinguish water produced from different coal zones.

  2. Passive remediation of coalbed natural gas co-produced water using zeolite.

    PubMed

    Belbase, Shashidhar; Urynowicz, Michael A; Vance, George F; Dangi, Mohan B

    2013-12-15

    Coalbed natural gas (CBNG) co-produced waters can contain sodium (Na(+)) concentrations that may be environmentally detrimental if discharged to receiving bodies of water or applied to land surfaces. A field demonstration and companion laboratory studies were conducted to evaluate the use of a Bear River zeolite (BR-zeolite) for mitigating impacts associated with Na(+) in CBNG waters. Bench-scale kinetic and adsorption isotherm studies were performed to determine both the rate and extent of sodium Na(+) adsorption and assess the effects of bicarbonate (HCO3(-)) and chloride (Cl(-)) anions. Results of these studies showed that the adsorption of Na(+) on BR-zeolite followed the Langmuir adsorption model with maximum adsorption equal to 21 and 18 g Na(+)/kg zeolite with 0.0012 and 0.0006 L/mg Langmuir coefficients (KL) for sodium bicarbonate and sodium chloride, respectively. The kinetics study indicated that the sorption of Na(+) was inversely related to the size of the zeolite particles with significantly greater adsorption for smaller particles. The field demonstration evaluated the effectiveness of BR-zeolite for mitigating infiltration losses from Na(+) in CBNG waters. The field site utilized 12 open boreholes, each installed to a depth of approximately 1.8 m. Each borehole was lined with a 3.0 m long, 15 cm diameter schedule 40 PVC pipe and fitted with an automatic data logging pressure transducer for measuring water levels over time. The BR-zeolite was found to mitigate much of the deleterious effect that high sodium adsorption ratio (SAR = 27 (mol/m(3))(1/2)) CBNG co-produced water had on soil permeabilities.

  3. [Copper in methane oxidation: a review].

    PubMed

    Su, Yao; Kong, Jiao-Yan; Zhang, Xuan; Xia, Fang-Fang; He, Ruo

    2014-04-01

    Methane bio-oxidation plays an important role in the global methane balance and warming mitigation, while copper has a crucial function in methane bio-oxidation. On one side, copper is known to be a key factor in regulating the expression of the genes encoding the two forms of methane monooxygenases (MMOs) and is the essential metal element of the particulate methane monooxygenase (pMMO). On the other side, the content and fractionation of copper in the environment have great effects on the distribution of methanotrophs and their metabolic capability of methane and non-methane organic compounds, as well as on the copper-specific uptake systems in methanotrophs. Thus, it is meaningful to know the role of copper in methane bio-oxidation for comprehensive understanding of this process and is valuable for guiding the application of methanotrophs in greenhouse gas removal and pollution remediation. In this paper, the roles of copper in methane oxidation were reviewed, including the effect of copper on methanotrophic community structure and activity, the expression and activity of MMOs as well as the copper uptake systems in methanotrophs. The future studies of copper and methane oxidation were also discussed.

  4. Photocatalytic conversion of methane to methanol

    SciTech Connect

    Taylor, C.E.; Noceti, R.P.; D`Este, J.R.

    1995-12-31

    A long-term goal of our research group is the exploration of novel pathways for the direct oxidation of methane to liquid fuels, chemicals, and intermediates. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol is attractive. The products of reaction, methanol and hydrogen, are both commercially desirable, methanol being used as is or converted to a variety of other chemicals, and the hydrogen could be utilized in petroleum and/or chemical manufacturing. Methane is produced as a by-product of coal gasification. Depending upon reactor design and operating conditions, up to 18% of total gasifier product may be methane. In addition, there are vast proven reserves of geologic methane in the world. Unfortunately, a large fraction of these reserves are in regions where there is little local demand for methane and it is not economically feasible to transport it to a market. There is a global research effort under way in academia, industry, and government to find methods to convert methane to useful, more readily transportable and storable materials. Methanol, the initial product of methane oxidation, is a desirable product of conversion because it retains much of the original energy of the methane while satisfying transportation and storage requirements. Investigation of direct conversion of methane to transportation fuels has been an ongoing effort at PETC for over 10 years. One of the current areas of research is the conversion of methane to methanol, under mild conditions, using light, water, and a semiconductor photocatalyst. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol, is attractive. Research in the laboratory is directed toward applying the techniques developed for the photocatalytic splitting of the water and the photochemical conversion of methane.

  5. Compilation of coal-bed folios to characterize coal-thickness and coal-quality distribution in eastern Kentucky coalfield

    SciTech Connect

    Sergeant, R.E.; Davidson, O.B.; Cobb, J.C.

    1988-08-01

    Coal-bed folios are currently being prepared for major coal beds in the Eastern Kentucky coalfield. These comprehensive folios contain information on geologic setting, coal setting, coal quality, coal resources, and environments of deposition for each of the selected coal beds. Additionally, each folio contains a series of maps (at a scale of 1:500,000) and geologic cross sections. Individual structure, isopach, coal-quality (sulfur, ash, and Btu), and overburden maps are prepared in conjunction with longitudinal and transverse geologic cross sections. The folios are compiled using field-measurement and chemical-analysis data maintained by the Kentucky Geological Survey in its Kentucky Coal Resources Information System (KCRIS). KCRIS is a computer-based, fully integrated data storage and retrieval system that contains coal-thickness measurements, coal-quality analyses, core descriptions, petrographic analyses, and lithologic descriptions. Maps and cross sections for the coal-bed folios are computer generated using coal-thickness and coal-quality information from the KCRIS data set. Grid matrices are prepared for the appropriate coal-thickness measurements or coal-quality parameters. These grids are then modeled or contoured on the Survey's computer system using MINEX software, and the resulting plot files are then plotted on a multi-pen or ink-jet plotter.

  6. Pluto: evidence for methane frost.

    PubMed

    1976-11-19

    Infrared photometry (1.2 to 2.2 micrometers) of Pluto provides evidence for frozen methane on the surface of the planet. This appears to be the first observational indication of this ice in the solar system. Its presence on Pluto suggests that the planet's albedo (reflectance) may be >/= 0.4 and that its diameter may be less than that of the moon.

  7. Titan's Methane Cycle is Closed

    NASA Astrophysics Data System (ADS)

    Hofgartner, J. D.; Lunine, J. I.

    2013-12-01

    Doppler tracking of the Cassini spacecraft determined a polar moment of inertia for Titan of 0.34 (Iess et al., 2010, Science, 327, 1367). Assuming hydrostatic equilibrium, one interpretation is that Titan's silicate core is partially hydrated (Castillo-Rogez and Lunine, 2010, Geophys. Res. Lett., 37, L20205). These authors point out that for the core to have avoided complete thermal dehydration to the present day, at least 30% of the potassium content of Titan must have leached into an overlying water ocean by the end of the core overturn. We calculate that for probable ammonia compositions of Titan's ocean (compositions with greater than 1% ammonia by weight), that this amount of potassium leaching is achievable via the substitution of ammonium for potassium during the hydration epoch. Formation of a hydrous core early in Titan's history by serpentinization results in the loss of one hydrogen molecule for every hydrating water molecule. We calculate that complete serpentinization of Titan's core corresponds to the release of more than enough hydrogen to reconstitute all of the methane atoms photolyzed throughout Titan's history. Insertion of molecular hydrogen by double occupancy into crustal clathrates provides a storage medium and an opportunity for ethane to be converted back to methane slowly over time--potentially completing a cycle that extends the lifetime of methane in Titan's surface atmosphere system by factors of several to an order of magnitude over the photochemically-calculated lifetime.

  8. Ceramic membranes for methane conversion

    SciTech Connect

    Balachandran, U.; Dusek, J.T.; Mieville, R.L.; Maiya, P.S.; Kleefisch, M.S.; Pei, S.; Kobylinski, T.P.; Udovich, C.A.

    1994-09-01

    In conventional conversion of methane to syngas, a significant cost of the partial oxidation process is that of the oxygen plant. In this report, the authors offer a technology that is based on dense ceramic membranes and that uses air as the oxidant for methane-conversion reactions, thus eliminating the need for the oxygen plant. Certain ceramic materials exhibit both electronic and ionic conductivities (of particular interest is oxygen-ion conductivity). These materials transport not only oxygen ions (functioning as selective oxygen separators) but also electrons back from the reactor side to the oxygen/reduction interface. No external electrodes are required and if the driving potential of transport is sufficient, the partial-oxidation reactions should be spontaneous. Such a system will operate without an externally applied potential. Oxygen is transported across the ceramic material in the form of oxygen anions, not oxygen molecules. Long tubes of Sr-Fe-Co-O (SFC) membrane were fabricated by plastic extrusion, and thermal stability of the tubes was studied as a function of oxygen partial pressure and high-temperature XRD. Mechanical properties were measured and found to be acceptable for a reactor material. Fracture of certain SFC tubes was the consequence of an oxygen gradient that introduced a volumetric lattice difference between the inner and outer walls. However, tubes made with a particular stoichiometry (SFC-2) provided methane conversion efficiencies of >99% in a reactor and some of these tubes have operated for up to {approx}1,000 h.

  9. Evidence for methane in Martian meteorites

    PubMed Central

    Blamey, Nigel J. F.; Parnell, John; McMahon, Sean; Mark, Darren F.; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R. M.; Banerjee, Neil R.; Flemming, Roberta L.

    2015-01-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity. PMID:26079798

  10. Evidence for methane in Martian meteorites

    NASA Astrophysics Data System (ADS)

    Blamey, Nigel J. F.; Parnell, John; McMahon, Sean; Mark, Darren F.; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R. M.; Banerjee, Neil R.; Flemming, Roberta L.

    2015-06-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  11. Evidence for methane in Martian meteorites.

    PubMed

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-01-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity. PMID:26079798

  12. Emerging topics in marine methane biogeochemistry.

    PubMed

    Valentine, David L

    2011-01-01

    Our knowledge of physical, chemical, geological and biological processes affecting methane in the ocean and in underlying sediments is expanding at a rapid pace. On first inspection, marine methane biogeochemistry appears simple: Methane distribution in sediment is set by the deposition pattern of organic material, and the balance of sources and sinks keeps its concentration low in most waters. However, recent research reveals that methane is affected by complex biogeochemical processes whose interactions are understood only at a superficial level. Such processes span the deep-subsurface, near subsurface, and ocean waters, and relate primarily to the production, consumption, and transport of methane. The purpose of this synthesis is to examine select processes within the framework of methane biogeochemistry, to formulate hypotheses on how they might operate and interact with one another, and to consider their controls. PMID:21329202

  13. Methane-induced haemolysis of human erythrocytes.

    PubMed Central

    Batliwala, H; Somasundaram, T; Uzgiris, E E; Makowski, L

    1995-01-01

    Human erythrocytes were exposed to high concentrations of methane and nitrogen through the application of elevated partial pressures of these gas molecules. Cell leakage (haemolysis) was measured for cells exposed to these gases under a wide range of experimental conditions. Application of methane produces haemolysis at pressures far below the hydrostatic pressures known to disrupt membrane or protein structure. The effects of changes in buffer, temperature, diffusion rate and detergents were studied. Methane acts co-operatively with detergents to produce haemolysis at much lower detergent concentration than is required in the absence of methane or in the presence of nitrogen. At sufficiently high concentrations of methane, all cells are haemolysed. Increased temperature enhances the effect. Methane produces 50% haemolysis at a concentration of about 0.33 M compared with about 7.5 M methanol required for the same degree of haemolysis. Images Figure 1 PMID:7733880

  14. Evidence for methane in Martian meteorites.

    PubMed

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-06-16

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  15. Thermal properties of methane gas hydrates

    USGS Publications Warehouse

    Waite, William F.

    2007-01-01

    Gas hydrates are crystalline solids in which molecules of a “guest” species occupy and stabilize cages formed by water molecules. Similar to ice in appearance (fig. 1), gas hydrates are stable at high pressures and temperatures above freezing (0°C). Methane is the most common naturally occurring hydrate guest species. Methane hydrates, also called simply “gas hydrates,” are extremely concentrated stores of methane and are found in shallow permafrost and continental margin sediments worldwide. Brought to sea-level conditions, methane hydrate breaks down and releases up to 160 times its own volume in methane gas. The methane stored in gas hydrates is of interest and concern to policy makers as a potential alternative energy resource and as a potent greenhouse gas that could be released from sediments to the atmosphere and ocean during global warming. In continental margin settings, methane release from gas hydrates also is a potential geohazard and could cause submarine landslides that endanger offshore infrastructure. Gas hydrate stability is sensitive to temperature changes. To understand methane release from gas hydrate, the U.S. Geological Survey (USGS) conducted a laboratory investigation of pure methane hydrate thermal properties at conditions relevant to accumulations of naturally occurring methane hydrate. Prior to this work, thermal properties for gas hydrates generally were measured on analog systems such as ice and non-methane hydrates or at temperatures below freezing; these conditions limit direct comparisons to methane hydrates in marine and permafrost sediment. Three thermal properties, defined succinctly by Briaud and Chaouch (1997), are estimated from the experiments described here: - Thermal conductivity, λ: if λ is high, heat travels easily through the material. - Thermal diffusivity, κ: if κ is high, it takes little time for the temperature to rise in the material. - Specific heat, cp: if cp is high, it takes a great deal of heat to

  16. Carbon isotope fractionation during microbial methane oxidation

    NASA Astrophysics Data System (ADS)

    Barker, James F.; Fritz, Peter

    1981-09-01

    Methane, a common trace constituent of groundwaters, occasionally makes up more than 20% of the total carbon in groundwaters1,2. In aerobic environments CH4-rich waters can enable microbial food chain supporting a mixed culture of bacteria with methane oxidation as the primary energy source to develop3. Such processes may influence the isotopic composition of the residual methane and because 13C/12C analyses have been used to characterize the genesis of methanes found in different environments, an understanding of the magnitude of such effects is necessary. In addition, carbon dioxide produced by the methane-utilizing bacteria can be added to the inorganic carbon pool of affected groundwaters. We found carbon dioxide experimentally produced by methane-utilizing bacteria to be enriched in 12C by 5.0-29.6‰, relative to the residual methane. Where methane-bearing groundwaters discharged into aerobic environments microbial methane oxidation occurred, with the residual methane becoming progressively enriched in 13C. Various models have been proposed to explain the 13C/12C and 14C content of the dissolved inorganic carbon (DIC) of groundwaters in terms of additions or losses during flow in the subsurface4,5. The knowledge of both stable carbon isotope ratios in various pools and the magnitude of carbon isotope fractionation during various processes allows geochemists to use the 13C/12C ratio of the DIC along with water chemistry to estimate corrected 14C groundwater ages4,5. We show here that a knowledge of the carbon isotope fractionation between CH4 and CO2 during microbial methane-utilization could modify such models for application to groundwaters affected by microbial methane oxidation.

  17. Methane Pyrolysis and Disposing Off Resulting Carbon

    NASA Technical Reports Server (NTRS)

    Sharma, P. K.; Rapp, D.; Rahotgi, N. K.

    1999-01-01

    Sabatier/Electrolysis (S/E) is a leading process for producing methane and oxygen for application to Mars ISPP. One significant problem with this process is that it produces an excess of methane for combustion with the amount of oxygen that is produced. Therefore, one must discard roughly half of the methane to obtain the proper stoichiometric methane/oxygen mixture for ascent from Mars. This is wasteful of hydrogen, which must be brought from Earth and is difficult to transport to Mars and store on Mars. To reduced the problem of transporting hydrogen to Mars, the S/E process can be augmented by another process which reduces overall hydrogen requirement. Three conceptual approaches for doing this are (1) recover hydrogen from the excess methane produced by the S/E process, (2) convert the methane to a higher hydrocarbon or other organic with a lower H/C ratio than methane, and (3) use a separate process (such as zirconia or reverse water gas shift reaction) to produce additional oxygen, thus utilizing all the methane produced by the Sabatier process. We report our results here on recovering hydrogen from the excess methane using pyrolysis of methane. Pyrolysis has the advantage that it produces almost pure hydrogen, and any unreacted methane can pass through the S/E process reactor. It has the disadvantage that disposing of the carbon produced by pyrolysis presents difficulties. Hydrogen may be obtained from methane by pyrolysis in the temperature range 10000-12000C. The main reaction products are hydrogen and carbon, though very small amounts of higher hydrocarbons, including aromatic hydrocarbons are formed. The conversion efficiency is about 95% at 12000C. One needs to distinguish between thermodynamic equilibrium conversion and conversion limited by kinetics in a finite reactor.

  18. Evaluation of methane emissions from Taiwanese paddies.

    PubMed

    Liu, Chen-Wuing; Wu, Chung-Yi

    2004-10-15

    The main greenhouse gases are carbon dioxide, methane and nitrous oxide. Methane is the most important because the warming effect of methane is 21 times greater than that of carbon dioxide. Methane emitted from rice paddy fields is a major source of atmospheric methane. In this work, a methane emission model (MEM), which integrates climate change, plant growth and degradation of soil organic matter, was applied to estimate the emission of methane from rice paddy fields in Taiwan. The estimated results indicate that much methane is emitted during the effective tillering and booting stages in the first crop season and during the transplanting stage in the second crop season in a year. Sensitivity analysis reveals that the temperature is the most important parameter that governs the methane emission rate. The order of the strengths of the effects of the other parameters is soil pH, soil water depth (SWD) and soil organic matter content. The masses of methane emitted from rice paddy fields of Taiwan in the first and second crop seasons are 28,507 and 350,231 tons, respectively. The amount of methane emitted during the second crop season is 12.5 times higher than that emitted in the first crop season. With a 12% reduction in planted area during the second crop season, methane emission could be reduced by 21%. In addition, removal of rice straw left from the first crop season and increasing the depth of flooding to 25 cm are also strategies that could help reduce annual emission by up to 18%.

  19. Ebullitive methane emissions from oxygenated wetland streams.

    PubMed

    Crawford, John T; Stanley, Emily H; Spawn, Seth A; Finlay, Jacques C; Loken, Luke C; Striegl, Robert G

    2014-11-01

    Stream and river carbon dioxide emissions are an important component of the global carbon cycle. Methane emissions from streams could also contribute to regional or global greenhouse gas cycling, but there are relatively few data regarding stream and river methane emissions. Furthermore, the available data do not typically include the ebullitive (bubble-mediated) pathway, instead focusing on emission of dissolved methane by diffusion or convection. Here, we show the importance of ebullitive methane emissions from small streams in the regional greenhouse gas balance of a lake and wetland-dominated landscape in temperate North America and identify the origin of the methane emitted from these well-oxygenated streams. Stream methane flux densities from this landscape tended to exceed those of nearby wetland diffusive fluxes as well as average global wetland ebullitive fluxes. Total stream ebullitive methane flux at the regional scale (103 Mg C yr(-1) ; over 6400 km(2) ) was of the same magnitude as diffusive methane flux previously documented at the same scale. Organic-rich stream sediments had the highest rates of bubble release and higher enrichment of methane in bubbles, but glacial sand sediments also exhibited high bubble emissions relative to other studied environments. Our results from a database of groundwater chemistry support the hypothesis that methane in bubbles is produced in anoxic near-stream sediment porewaters, and not in deeper, oxygenated groundwaters. Methane interacts with other key elemental cycles such as nitrogen, oxygen, and sulfur, which has implications for ecosystem changes such as drought and increased nutrient loading. Our results support the contention that streams, particularly those draining wetland landscapes of the northern hemisphere, are an important component of the global methane cycle.

  20. Draft Genome Sequence of Desulfocarbo indianensis SCBM, a New Genus of Sulfate-Reducing Bacteria, Isolated from Water Extracted from an Active Coalbed Methane Gas Well.

    PubMed

    An, Thuy T; Picardal, Flynn W

    2015-09-03

    We used Illumina MiSeq technology to sequence the whole genome of Desulfocarbo indianensis SCBM, a new genus of sulfate-reducing bacteria isolated from a coal bed in Indiana, USA. This draft genome represents the first sequenced genome of the genus Desulfocarbo and the second known genome of the order Desulfarculales.

  1. Inhibition Experiments on Anaerobic Methane Oxidation †

    PubMed Central

    Alperin, Marc J.; Reeburgh, William S.

    1985-01-01

    Anaerobic methane oxidation is a general process important in controlling fluxes of methane from anoxic marine sediments. The responsible organism has not been isolated, and little is known about the electron acceptors and substrates involved in the process. Laboratory evidence indicates that sulfate reducers and methanogens are able to oxidize small quantities of methane. Field evidence suggests anaerobic methane oxidation may be linked to sulfate reduction. Experiments with specific inhibitors for sulfate reduction (molybdate), methanogenesis (2-bromoethanesulfonic acid), and acetate utilization (fluoroacetate) were performed on marine sediments from the zone of methane oxidation to determine whether sulfate-reducing bacteria or methanogenic bacteria are responsible for methane oxidation. The inhibition experiment results suggest that methane oxidation in anoxic marine sediments is not directly mediated by sulfate-reducing bacteria or methanogenic bacteria. Our results are consistent with two possibilities: anaerobic methane oxidation may be mediated by an unknown organism or a consortium involving an unknown methane oxidizer and sulfate-reducing bacteria. PMID:16346921

  2. [Sources of Methane in the Boreal Region

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In determining the global methane budget the sources of methane must be balanced with the sinks and atmospheric inventory. The approximate contribution of the different methane sources to the budget has been establish showing the major terrestrial inputs as rice, wetlands, bogs, fens, and tundra. Measurements and modeling of production in these sources suggest that temperature, water table height and saturation along with substratum composition are important in controlling methane production and emission. The isotopic budget of 13 C and D/H in methane can be used as a tool to clarify the global budget. This approach has achieved success at constraining the inputs. Studies using the isotopic approach place constraints on global methane production from different sources. Also, the relation between the two biogenic production pathways, acetate fermentation and CO2 reduction, and the effect of substratum composition can be made using isotope measurements shows the relation between the different biogenic, thermogenic and anthropogenic sources of methane as a function of the carbon and hydrogen isotope values for each source and the atmosphere, tropospheric composition. Methane emissions from ponds and fens are a significant source in the methane budget of the boreal region. An initial study in 1993 and 1994 on the isotopic composition of this methane source and the isotopic composition in relation to oxidation of methane at the sediment surface of the ponds or fen was conducted as part of our BOREAS project. The isotopic composition of methane emitted by saturated anoxic sediment is dependent on the sediment composition and geochemistry, but will be influenced by in situ oxidation, in part, a function of rooted plant activity. The influence of oxidation mediated by rooted plant activities on the isotopic composition of methane is not well known and will depend on the plant type, sediment temperature, and numerous other variables. Information on this isotopic composition

  3. Methane flux time series for tundra environments

    SciTech Connect

    Whalen, S.C.; Reeburgh, W.E. )

    1988-12-01

    Seasonal measurements of net methane flux were made at permanent sites representing important components of arctic tundra. The sites include Eriophorum tussocks, intertussock depressions, moss-covered areas, and Carex stands. Methane fluxes showed high diel, seasonal, intra site, and between site variability. Eriophorum tussocks and Carex dominated methane release to the atmosphere, with mean annual net methane fluxes of 8.05 + or{minus}2.50 g CH{sub 4}/sq m and 4.88 + or{minus}0.73 g CH{sub 4}/sq m, respectively. Methane fluxes form the moss sites and intertussock depressions were much lower. Over 90% of the mean annual methane flux from the Eriophorum, intertussock depressions, and Carex sites occurred between thaw and freeze-up. Some 40% of the mean annual methane flux from the moss sites occurred during winter. Composite methane fluxes for tussock tundra and Carex-dominated wet meadow tundra environments were produced by weighting measured component fluxes according to areal coverage. Tussock and wet meadow tundra account for an estimated global methane emission of 19-33 Tg/yr. 39 refs., 7 figs., 2 tabs.

  4. GRI methane chemistry program review meeting

    SciTech Connect

    Dignon, J.; Grant, K.; Grossman, A.; Wuebles, D.; Brasseur, G.; Madronich, S.; Huang, T.; Chang, J.; Lott, B.

    1997-02-01

    Methane is an important greenhouse gas which affects the atmosphere directly by the absorption and re-emission of infrared radiation as well as indirectly, through chemical interactions. Emissions of several important greenhouse gases (GHGS) including methane are increasing, mainly due to human activity. Higher concentrations of these gases in the atmosphere are projected to cause a decrease in the amount of infrared radiation escaping to space, and a subsequent warming of global climate. It is therefore vital to understand not only the causes of increased production of methane and other GHGS, but the effect of higher GHG concentrations on climate, and the possibilities for reductions of these emissions. In GRI-UIUC methane project, the role of methane in climate change and greenhouse gas abatement strategies is being studied using several distinct approaches. First, a detailed treatment of the mechanisms controlling each important methane source and sink, and hence the atmospheric concentration of methane, is being developed for use with the UIUC Integrated Science Assessment Model. The focus of this study is to resolve the factors which determine methane emissions and removal, including human population, land use, energy demand, global temperature, and regional concentrations of the hydroxyl radical, carbon monoxide, nitrous oxides, non-methane hydrocarbons, water vapor, tropospheric and stratospheric ozone.

  5. Relationships between methane production and emission to lacunal methane concentrations in rice

    NASA Astrophysics Data System (ADS)

    Byrd, G. T.; Fisher, F. M.; Sass, R. L.

    2000-03-01

    We measured lacunal methane concentrations in field-grown rice plants as a correlative to both methane production and emissions. Using a gas-tight syringe, 100-μL samples were withdrawn from plant lacunar spaces below the water level and diluted to provide enough volume for analysis by gas chromatography. Lacunal methane concentrations increased throughout the season and, for each sampling date, were usually significantly higher in the cultivars Mars and Cypress (high emitters) when compared with Lemont and Della (low emitters). The field site influenced lacunal methane concentrations, wherein greater lacunal methane concentrations corresponded with greater methane. Methane emission rates were positively correlated with plant lacunal methane concentrations for each cultivar, with an improvement in the relationship during the preheading season. With increases in methane production determined by emissions following field-induced anoxia, lacunal methane concentrations increased accordingly. Lacunal methane concentrations also clearly increased as plant biomass increased, but the relationship depended on field location, which also influenced emissions. Sampling lacunal methane concentrations of rice plants, although labor intensive, is quite flexible, using little field equipment, and may provide an effective alternative to large-scale flux measurements in areas not easily accessible.

  6. Pasture-scale measurement of methane emissions of grazing cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying methane emission of cattle grazing on southern Great Plains pastures using micrometeorology presents several challenges. Cattle are elevated, mobile point sources of methane, so that knowing their location in relation to atmospheric methane concentration measurements becomes critical. St...

  7. Potential methane production and methane oxidation rates in peatland ecosystems of the Appalachian Mountains, United States

    SciTech Connect

    Yavitt, J.B.; Lang, G.E.; Downey, D.M. )

    1988-09-01

    Potential rates of methane production and carbon dioxide production were measured on 11 dates in 1986 in peat from six plant communities typical of moss-dominated peatlands in the Appalachian Mountains. Annual methane production ranged from 2.7 to 17.5 mol/sq m, and annual carbon dioxide production ranged from 30.6 to 79.0 mol/sq m. The wide range in methane production values among the communities found within a single peatland indicates that obtaining one production value for a peatland may not be appropriate. Low temperature constrained the potential for methane production in winter, while the chemical quality of the peat substrate appears to control methane production in the summer. Methane oxidation was measured throughout the peat profile to a depth of 30 cm. Values for methane oxidation ranged from 0.08 to 18.7 microM/hr among the six plant communities. Aerobic methane-oxidizing bacteria probably mediated most of the activity. On a daily basis during the summer, between 11 and 100% of the methane produced is susceptible to oxidation within the peat column. Pools of dissolved methane and dissolved carbon dioxide in pore waters were less than 0.2 and less than 1.0 mol/sq m, respectively, indicating that methane does not accumulate in the pore waters. Peatlands have been considered as an important source of biologically produced methane. Despite the high rates of methane production, the high rates of methane oxidation dampen the potential emission of methane to the atmosphere. 41 refs., 7 figs., 4 tabs.

  8. Composition and origin of coalbed gases in the Lower Silesian basin, southwest Poland

    USGS Publications Warehouse

    Kotarba, M.J.; Rice, D.D.

    2001-01-01

    Coalbed gases in the Lower Silesian Coal Basin (LSCB) of Poland are highly variable in both their molecular and stable isotope compositions. Geochemical indices and stable isotope ratios vary within the following ranges: hydrocarbon (CHC) index CHC = CH4/(C2H6+C3H8) from 1.1 to 5825, wet gas (C2+) index C2+ = (C2H6+ C3H8+ C4H10+ C5H12) / (CH4+ C2H6+ C3H8+ C4H10+ C5H12) 100 (%) from 0.0 to 48.3%, CO2-CH4 (CDMI) index CDMI = CO2/ (CO2+ CH4) 100 (%) from 0.1 to 99.9%, ??13C(CH4) from -66.1 to -24.6%o, ??D(CH4) from -266 to -117%o, ??13C(C2H6) from -27.8 to -22.8%o, and ??13C(CO2) from -26.6 to 16.8%o. Isotopic studies reveal the presence of 3 genetic types of natural gases: thermogenic (CH4, higher gaseous hydrocarbons, and CO2), endogenic CO2, and microbial CH4 and CO2. Thermogenic gases resulted from coalification processes, which were probably completed by Late Carboniferous and Early Permian time. Endogenic CO2 migrated along the deep-seated faults from upper mantle and/or magma chambers. Minor volumes of microbial CH4 and CO2 occur at shallow depths close to the abandoned mine workings. "Late-stage" microbial processes have commenced in the Upper Cretaceous and are probably active at present. However, depth-related isotopic fractionation which has resulted from physical and physicochemical (e.g. diffusion and adsorption/desorption) processes during gas migration cannot be neglected. The strongest rock and gas outbursts occur only in those parts of coal deposits of the LSCB which are dominated by large amounts of endogenic CO2. ?? 2001 Elsevier Science Ltd.

  9. Origin of long-chain alkylcyclohexanes and alkylbenzenes in a coal-bed wax

    NASA Astrophysics Data System (ADS)

    Dong, Ji-Zhou; Vorkink, William P.; Lee, Milton L.

    1993-02-01

    A coal-bed wax was fractionated and analyzed using capillary column GC and combined GC/MS. It was found that the major components in the wax were n-alkanes (55.6%), cyclic/branched alkanes (26.0%), and several homologous series of alkylbenzenes (5.7%). All alkylbenzene isomers (except 6- n-alkyl- m-xylene) were positively identified by comparison with the retention times and mass spectra of newly synthesized authentic standards. 5- n-Alkyl- m-xylene, 2- n-alkyl- p-xylene, 4- n-alkyl- m-xylene, 4- n-alkyl- o-xylene, 2- n-alkyl- m-xylene, and 3- n-alkyl- o-xylene were identified for the first time from geological sources. All of these long-chain alkyl compounds (e.g., n-alkylcyclohexanes, n-alkylbenzenes, n-alkyl- o-toluenes, n-alkyl- p-toluenes, and 5- n-alkyl- m-xylenes) have similar total carbon number distributions and maxima with a slight even over odd carbon number preference between C 28-C 30. Moreover, the carbon number distributions of these compounds resembled those of the n-alkanes found in the same wax with slight odd over even carbon preference between C 27-C 21. This indicates that the alkylcyclohexanes and alkylbenzenes may have the same fatty acid precursors as the n-alkanes. The alkylcyclohexanes and alkylbenzenes could have been formed by direct cyclization and aromatization, while the n-alkanes could have been formed by decarboxylation of the straight chain fatty acids. This explanation is further supported by the identification of homologous series of tetramethyl- n-alkylbenzenes and pentamethyl- n-alkylbenzenes with relatively high abundances at C 15, C 16, and C 18, and a fatty acid distribution with maxima at C 16 and C 18. Based on these findings, mechanisms for the conversion of fatty acids or alcohols to alkylcyclohexanes and alkylbenzenes are proposed.

  10. Assessment of Appalachian Basin Oil and Gas Resources: Carboniferous Coal-bed Gas Total Petroleum System

    USGS Publications Warehouse

    Milici, Robert C.

    2004-01-01

    The Carboniferous Coal-bed Gas Total Petroleum System, lies within the central and northern parts of the Appalachian coal field. It consists of five assessment units (AU): the Pocahontas Basin in southwestern Virginia, southern West Virginia, and eastern Kentucky, the Central Appalachian Shelf in Tennessee, eastern Kentucky and southern West Virginia, East Dunkard (Folded) in western Pennsylvania and northern West Virginia, West Dunkard (Unfolded) in Ohio and adjacent parts of Pennsylvania and West Virginia, and the Appalachian Anthracite and Semi-Anthracite AU in Pennsylvania and Virginia. Of these, only the Pocahontas Basin and West Dunkard (Folded) AU were assessed quantitatively by the U.S. Geological survey in 2002 as containing about 3.6 and 4.8 Tcf of undiscovered, technically recoverable gas, respectively (Milici and others, 2003). In general, the coal beds of this Total Petroleum System, which are both the source rock and reservoir, were deposited together with their associated sedimentary strata in Mississippian and Pennsylvanian (Carboniferous) time. The generation of biogenic (microbial) gas probably began almost immediately as the peat deposits were first formed. Microbial gas generation is probably occurring at present to some degree throughout the basin, where the coal beds are relatively shallow and wet. With sufficient depth of burial, compaction, and coalification during the late Paleozoic and Early Mesozoic, the coal beds were heated sufficiently to generate thermogenic gas in the eastern part of the Appalachian basin. Trap formation began initially with the deposition of the paleopeat deposits during the Mississippian, and continued into the Late Pennsylvanian and Permian as the Appalachian Plateau strata were deformed during the Alleghanian orogeny. Seals are the connate waters that occupy fractures and larger pore spaces within the coal beds as well as the fine-grained siliciclastic sedimentary strata that are intercalated with the coal. The

  11. Anaerobic Methane Oxidation in Soils - revealed using 13C-labelled methane tracers

    NASA Astrophysics Data System (ADS)

    Riekie, G. J.; Baggs, E. M.; Killham, K. S.; Smith, J. U.

    2008-12-01

    In marine sediments, anaerobic methane oxidation is a significant biogeochemical process limiting methane flux from ocean to atmosphere. To date, evidence for anaerobic methane oxidation in terrestrial environments has proved elusive, and its significance is uncertain. In this study, an isotope dilution method specifically designed to detect the process of anaerobic methane oxidation in methanogenic wetland soils is applied. Methane emissions of soils from three contrasting permanently waterlogged sites in Scotland are investigated in strictly anoxic microcosms to which 13C- labelled methane is added, and changes in the concentration and 12C/13C isotope ratios of methane and carbon dioxide are subsequently measured and used to calculate separate the separate components of the methane flux. The method used takes into account the 13C-methane associated with methanogenesis, and the amount of methane dissolved in the soil. The calculations make no prior assumptions about the kinetics of methane production or oxidation. The results indicate that methane oxidation can take place in anoxic soil environments. The clearest evidence for anaerobic methane oxidation is provided by soils from a minerotrophic fen site (pH 6.0) in Bin Forest underlain by ultra-basic and serpentine till. In the fresh soil anoxic microcosms, net consumption methane was observed, and the amount of headspace 13C-CO2 increased at a greater rate than the 12+13C-CO2, further proof of methane oxidation. A net increase in methane was measured in microcosms of soil from Murder Moss, an alkaline site, pH 6.5, with a strong calcareous influence. However, the 13C-CH4 data provided evidence of methane oxidation, both in the disappearance of C- CH4 and appearance of smaller quantities of 13C-CO2. The least alkaline (pH 5.5) microcosms, of Gateside Farm soil - a granitic till - exhibited net methanogenesis and the changes in 13C-CH4 and 13C-CO2 here followed the pattern expected if no methane is consumed

  12. Plasma catalytic reforming of methane

    SciTech Connect

    Bromberg, L.; Cohn, D.R.; Rabinovich, A.; Alexeev, N.

    1998-08-01

    Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This paper describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of dissociation and substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (50% H{sub 2}, 17% CO and 33% N{sub 2}, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2--3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H{sub 2} with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content ({approximately} 1.5%) with power densities of {approximately} 30 kW (H{sub 2} HHV)/liter of reactor, or {approximately} 10 m{sup 3}/hr H{sub 2} per liter of reactor. Power density should further increase with increased power and improved design.

  13. Sorption enhanced CO2 methanation.

    PubMed

    Borgschulte, Andreas; Gallandat, Noris; Probst, Benjamin; Suter, Riccardo; Callini, Elsa; Ferri, Davide; Arroyo, Yadira; Erni, Rolf; Geerlings, Hans; Züttel, Andreas

    2013-06-28

    The transformation from the fatuous consumption of fossil energy towards a sustainable energy circle is most easily marketable by not changing the underlying energy carrier but generating it from renewable energy. Hydrocarbons can be principally produced from renewable hydrogen and carbon dioxide collected by biomass. However, research is needed to increase the energetic and economic efficiency of the process. We demonstrate the enhancement of CO2 methanation by sorption enhanced catalysis. The preparation and catalytic activity of sorption catalysts based on Ni particles in zeolites is reported. The functioning of the sorption catalysis is discussed together with the determination of the reaction mechanism, providing implications for new ways in catalysis. PMID:23673365

  14. Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes

    PubMed Central

    Oswald, Kirsten; Milucka, Jana; Brand, Andreas; Littmann, Sten; Wehrli, Bernhard; Kuypers, Marcel M. M.; Schubert, Carsten J.

    2015-01-01

    Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological methane oxidation in the water column of the seasonally stratified Lake Rotsee. A zone of methane oxidation extending from the oxic/anoxic interface into anoxic waters was identified by chemical profiling of oxygen, methane and δ13C of methane. Incubation experiments with 13C-methane yielded highest oxidation rates within the oxycline, and comparable rates were measured in anoxic waters. Despite predominantly anoxic conditions within the zone of methane oxidation, known groups of anaerobic methanotrophic archaea were conspicuously absent. Instead, aerobic gammaproteobacterial methanotrophs were identified as the active methane oxidizers. In addition, continuous oxidation and maximum rates always occurred under light conditions. These findings, along with the detection of chlorophyll a, suggest that aerobic methane oxidation is tightly coupled to light-dependent photosynthetic oxygen production both at the oxycline and in the anoxic bottom layer. It is likely that this interaction between oxygenic phototrophs and aerobic methanotrophs represents a widespread mechanism by which methane is oxidized in lake water, thus diminishing its release into the atmosphere. PMID:26193458

  15. Inhibition of Methane Oxidation by Methylococcus capsulatus with Hydrochlorofluorocarbons and Fluorinated Methanes

    PubMed Central

    Matheson, L. J.; Jahnke, L. L.; Oremland, R. S.

    1997-01-01

    The inhibition of methane oxidation by cell suspensions of Methylococcus capsulatus (Bath) exposed to hydrochlorofluorocarbon 21 (HCFC-21; difluorochloromethane [CHF(inf2)Cl]), HCFC-22 (fluorodichloromethane [CHFCl(inf2)]), and various fluorinated methanes was investigated. HCFC-21 inhibited methane oxidation to a greater extent than HCFC-22, for both the particulate and soluble methane monooxygenases. Among the fluorinated methanes, both methyl fluoride (CH(inf3)F) and difluoromethane (CH(inf2)F(inf2)) were inhibitory while fluoroform (CHF(inf3)) and carbon tetrafluoride (CF(inf4)) were not. The inhibition of methane oxidation by HCFC-21 and HCFC-22 was irreversible, while that by methyl fluoride was reversible. The HCFCs also proved inhibitory to methanol dehydrogenase, which suggests that they disrupt other aspects of C(inf1) catabolism in addition to methane monooxygenase activity. PMID:16535662

  16. High rates of anaerobic methane oxidation in freshwater wetlands reduce potential atmospheric methane emissions.

    PubMed

    Segarra, K E A; Schubotz, F; Samarkin, V; Yoshinaga, M Y; Hinrichs, K-U; Joye, S B

    2015-06-30

    The role of anaerobic oxidation of methane (AOM) in wetlands, the largest natural source of atmospheric methane, is poorly constrained. Here we report rates of microbially mediated AOM (average rate=20 nmol cm(-3) per day) in three freshwater wetlands that span multiple biogeographical provinces. The observed AOM rates rival those in marine environments. Most AOM activity may have been coupled to sulphate reduction, but other electron acceptors remain feasible. Lipid biomarkers typically associated with anaerobic methane-oxidizing archaea were more enriched in (13)C than those characteristic of marine systems, potentially due to distinct microbial metabolic pathways or dilution with heterotrophic isotope signals. On the basis of this extensive data set, AOM in freshwater wetlands may consume 200 Tg methane per year, reducing their potential methane emissions by over 50%. These findings challenge precepts surrounding wetland carbon cycling and demonstrate the environmental relevance of an anaerobic methane sink in ecosystems traditionally considered strong methane sources.

  17. Arctic permafrost: Microbial lid on subsea methane

    NASA Astrophysics Data System (ADS)

    Thornton, Brett F.; Crill, Patrick

    2015-08-01

    Submarine permafrost thaw in the Arctic has been suggested as a trigger for the release of large quantities of methane to the water column, and subsequently the atmosphere -- with important implications for global warming. Now research shows that microbial oxidation of methane at the thaw front can effectively prevent its release.

  18. Dairy livestock methane remediation and global warming.

    PubMed

    Nusbaum, Neil J

    2010-10-01

    One of the major greenhouse gases is the methane released from ruminants. Greenhouse gas emissions in the agricultural portion of the economy may benefit from biologically based remediation strategies, including potential use of probiotics in animal husbandry. A broad range of disciplines (including climatologists, microbiologists, biochemists, physical chemists, agricultural economists) can assist in biological strategies to reduce agricultural methane emissions.

  19. Chemical transformations of methane in trifluoroacetic acid

    NASA Astrophysics Data System (ADS)

    Vishnetskaya, M. V.; Svichkarev, O. M.; Budynina, E. M.; Mel'nikov, M. Ya.

    2013-12-01

    The reaction of methane conversion in anhydrous trifluoroacetic acid (TFA) is shown to take place at room temperature and atmospheric pressure and to result in the formation of a resinous product. Signals of ions with molecular weights of 684 and 700 are observed in MALDI-TOF spectra of the dry residue of methane conversion products.

  20. Thermophilic methane production and oxidation in compost.

    PubMed

    Jäckel, Udo; Thummes, Kathrin; Kämpfer, Peter

    2005-04-01

    Methane cycling within compost heaps has not yet been investigated in detail. We show that thermophilic methane oxidation occurred after a lag phase of up to one day in 4-week old, 8-week old and mature (>10-week old) compost material. The potential rate of methane oxidation was between 2.6 and 4.1 micromol CH4(gdw)(-1)h(-1). Profiles of methane concentrations within heaps of different ages indicated that 46-98% of the methane produced was oxidised by methanotrophic bacteria. The population size of thermophilic methanotrophs was estimated at 10(9) cells (gdw)(-1), based on methane oxidation rates. A methanotroph (strain KTM-1) was isolated from the highest positive step of a serial dilution series. This strain belonged to the genus Methylocaldum, which contains thermotolerant and thermophilic methanotrophs. The closest relative organism on the basis of 16S rRNA gene sequence identity was M. szegediense (>99%), a species originally isolated from hot springs. The temperature optimum (45-55 degrees C) for methane oxidation within the compost material was identical to that of strain KTM-1, suggesting that this strain was well adapted to the conditions in the compost material. The temperatures measured in the upper layer (0-40 cm) of the compost heaps were also in this range, so we assume that these organisms are capable of effectively reducing the potential methane emissions from compost.

  1. Abiotic production of methane in terrestrial planets.

    PubMed

    Guzmán-Marmolejo, Andrés; Segura, Antígona; Escobar-Briones, Elva

    2013-06-01

    On Earth, methane is produced mainly by life, and it has been proposed that, under certain conditions, methane detected in an exoplanetary spectrum may be considered a biosignature. Here, we estimate how much methane may be produced in hydrothermal vent systems by serpentinization, its main geological source, using the kinetic properties of the main reactions involved in methane production by serpentinization. Hydrogen production by serpentinization was calculated as a function of the available FeO in the crust, given the current spreading rates. Carbon dioxide is the limiting reactant for methane formation because it is highly depleted in aqueous form in hydrothermal vent systems. We estimated maximum CH4 surface fluxes of 6.8×10(8) and 1.3×10(9) molecules cm(-2) s(-1) for rocky planets with 1 and 5 M⊕, respectively. Using a 1-D photochemical model, we simulated atmospheres with volume mixing ratios of 0.03 and 0.1 CO2 to calculate atmospheric methane concentrations for the maximum production of this compound by serpentinization. The resulting abundances were 2.5 and 2.1 ppmv for 1 M⊕ planets and 4.1 and 3.7 ppmv for 5 M⊕ planets. Therefore, low atmospheric concentrations of methane may be produced by serpentinization. For habitable planets around Sun-like stars with N2-CO2 atmospheres, methane concentrations larger than 10 ppmv may indicate the presence of life.

  2. Carbon and hydrogen isotope composition and C-14 concentration in methane from sources and from the atmosphere: Implications for a global methane budget

    NASA Technical Reports Server (NTRS)

    Wahlen, Martin

    1994-01-01

    The topics covered include the following: biogenic methane studies; forest soil methane uptake; rice field methane sources; atmospheric measurements; stratospheric samples; Antarctica; California; and Germany.

  3. Nonequilibrium clumped isotope signals in microbial methane

    NASA Astrophysics Data System (ADS)

    Wang, David T.; Gruen, Danielle S.; Lollar, Barbara Sherwood; Hinrichs, Kai-Uwe; Stewart, Lucy C.; Holden, James F.; Hristov, Alexander N.; Pohlman, John W.; Morrill, Penny L.; Könneke, Martin; Delwiche, Kyle B.; Reeves, Eoghan P.; Sutcliffe, Chelsea N.; Ritter, Daniel J.; Seewald, Jeffrey S.; McIntosh, Jennifer C.; Hemond, Harold F.; Kubo, Michael D.; Cardace, Dawn; Hoehler, Tori M.; Ono, Shuhei

    2015-04-01

    Methane is a key component in the global carbon cycle, with a wide range of anthropogenic and natural sources. Although isotopic compositions of methane have traditionally aided source identification, the abundance of its multiply substituted “clumped” isotopologues (for example, 13CH3D) has recently emerged as a proxy for determining methane-formation temperatures. However, the effect of biological processes on methane’s clumped isotopologue signature is poorly constrained. We show that methanogenesis proceeding at relatively high rates in cattle, surface environments, and laboratory cultures exerts kinetic control on 13CH3D abundances and results in anomalously elevated formation-temperature estimates. We demonstrate quantitatively that H2 availability accounts for this effect. Clumped methane thermometry can therefore provide constraints on the generation of methane in diverse settings, including continental serpentinization sites and ancient, deep groundwaters.

  4. Optical constants of liquid and solid methane

    NASA Technical Reports Server (NTRS)

    Martonchik, John V.; Orton, Glenn S.

    1994-01-01

    The optical constants n(sub r) + in(sub i) of liquid methane and phase 1 solid methane were determined over the entire spectral range by the use of various data sources published in the literature. Kramers-Kronig analyses were performed on the absorption spectra of liquid methane at the boiling point (111 K) and the melting point (90 K) and on the absorption spectra of phase 1 solid methane at the melting point and at 30 K. Measurements of the static dielectric constant at these temperatures and refractive indices determined over limited spectral ranges were used as constraints in the analyses. Applications of methane optical properties to studies of outer solar system bodies are described.

  5. Methane flux from coastal salt marshes

    NASA Astrophysics Data System (ADS)

    Bartlett, K. B.; Harriss, R. C.; Sebacher, D. I.

    1985-06-01

    It is thought that biological methanogenesis in natural and agricultural wetlands and enteric fermentation in animals are the dominant sources of global tropospheric methane. It is pointed out that the anaerobic soils and sediments, where methanogenesis occurs, predominate in coastal marine wetlands. Coastal marine wetlands are generally believed to be approximately equal in area to freshwater wetlands. For this reason, coastal marine wetlands may be a globally significant source of atmospheric methane. The present investigation is concerned with the results of a study of direct measurements of methane fluxes to the atmosphere from salt marsh soils and of indirect determinations of fluxes from tidal creek waters. In addition, measurements of methane distributions in coastal marine wetland sediments and water are presented. The results of the investigation suggest that marine wetlands provide only a minor contribution to atmospheric methane on a global scale.

  6. Methane flux from coastal salt marshes

    NASA Technical Reports Server (NTRS)

    Bartlett, K. B.; Harriss, R. C.; Sebacher, D. I.

    1985-01-01

    It is thought that biological methanogenesis in natural and agricultural wetlands and enteric fermentation in animals are the dominant sources of global tropospheric methane. It is pointed out that the anaerobic soils and sediments, where methanogenesis occurs, predominate in coastal marine wetlands. Coastal marine wetlands are generally believed to be approximately equal in area to freshwater wetlands. For this reason, coastal marine wetlands may be a globally significant source of atmospheric methane. The present investigation is concerned with the results of a study of direct measurements of methane fluxes to the atmosphere from salt marsh soils and of indirect determinations of fluxes from tidal creek waters. In addition, measurements of methane distributions in coastal marine wetland sediments and water are presented. The results of the investigation suggest that marine wetlands provide only a minor contribution to atmospheric methane on a global scale.

  7. High methane emission from Siberian river floodplains

    NASA Astrophysics Data System (ADS)

    Mi, Yanjiao; van Huissteden, Ko; Dolman, Han

    2013-04-01

    Methane contributes significantly to global warming. Methane emission is essentially the net result of a balance between CH4 production by methanogenic bacteria in anaerobic soil zones, and CH4 oxidation by methanotrophic bacteria in aerated soil zones and plants. Arctic and sub-arctic permafrost holds a large amount of climate vulnerable carbon. In particular river floodplains are carbon-rich soils. River floodplains in this area are periodically or permanently submerged. The occurrence of flooding decreases soil oxygen availability, providing an ideal anaerobic environment for methane generation. Here we compare the chamber measurements of the methane flux from tundra and floodplain of the Kytalyk site in Northeast Siberia. Model experiments on this site have also been carried out in order to better explain spatial and temporal variations in methane emissions from northern permafrost. This serves as a basis for further model development including modeling of the flooding regime on the floodplain.

  8. Analysis of methane emissions from digested sludge.

    PubMed

    Schaum, C; Fundneider, T; Cornel, P

    2016-01-01

    The energetic use of sewage sludge is an important step in the generation of electricity and heat within a wastewater treatment plant (WWTP). For a holistic approach, methane emissions derived from anaerobic treatment have to be considered. Measurements show that methane dissolved in digested sludge can be analyzed via the vacuum salting out degassing method. At different WWTPs, dissolved methane was measured, showing a concentration range of approximately 7-37 mg CH4/L. The average concentration of dissolved methane in mesophilic digested sludge was approximately 29 mg CH4/L, which corresponds to an estimated yearly specific load of approximately 14-21 g CH4 per population equivalent. Comparisons between continuous and discontinuous digester feeding show that a temporary rise in the volume load causes increased concentrations of dissolved methane. Investigations using an industrial-scale digestion plant, consisting of three digestion tank operated in series, show comparable results. PMID:27054731

  9. Analysis of methane emissions from digested sludge.

    PubMed

    Schaum, C; Fundneider, T; Cornel, P

    2016-01-01

    The energetic use of sewage sludge is an important step in the generation of electricity and heat within a wastewater treatment plant (WWTP). For a holistic approach, methane emissions derived from anaerobic treatment have to be considered. Measurements show that methane dissolved in digested sludge can be analyzed via the vacuum salting out degassing method. At different WWTPs, dissolved methane was measured, showing a concentration range of approximately 7-37 mg CH4/L. The average concentration of dissolved methane in mesophilic digested sludge was approximately 29 mg CH4/L, which corresponds to an estimated yearly specific load of approximately 14-21 g CH4 per population equivalent. Comparisons between continuous and discontinuous digester feeding show that a temporary rise in the volume load causes increased concentrations of dissolved methane. Investigations using an industrial-scale digestion plant, consisting of three digestion tank operated in series, show comparable results.

  10. Nonequilibrium clumped isotope signals in microbial methane

    USGS Publications Warehouse

    Wang, David T.; Gruen, Danielle S.; Lollar, Barbara Sherwood; Hinrichs, Kai-Uwe; Stewart, Lucy C.; Holden, James F.; Hristov, Alexander N.; Pohlman, John W.; Morrill, Penny L.; Könneke, Martin; Delwiche, Kyle B.; Reeves, Eoghan P.; Sutcliffe, Chelsea N.; Ritter, Daniel J.; Seewald, Jeffrey S.; McIntosh, Jennifer C.; Hemond, Harold F.; Kubo, Michael D.; Cardace, Dawn; Hoehler, Tori M.; Ono, Shuhei

    2015-01-01

    Methane is a key component in the global carbon cycle with a wide range of anthropogenic and natural sources. Although isotopic compositions of methane have traditionally aided source identification, the abundance of its multiply-substituted “clumped” isotopologues, e.g., 13CH3D, has recently emerged as a proxy for determining methane-formation temperatures; however, the impact of biological processes on methane’s clumped isotopologue signature is poorly constrained. We show that methanogenesis proceeding at relatively high rates in cattle, surface environments, and laboratory cultures exerts kinetic control on 13CH3D abundances and results in anomalously elevated formation temperature estimates. We demonstrate quantitatively that H2 availability accounts for this effect. Clumped methane thermometry can therefore provide constraints on the generation of methane in diverse settings, including continental serpentinization sites and ancient, deep groundwaters.

  11. Activated carbon monoliths for methane storage

    NASA Astrophysics Data System (ADS)

    Chada, Nagaraju; Romanos, Jimmy; Hilton, Ramsey; Suppes, Galen; Burress, Jacob; Pfeifer, Peter

    2012-02-01

    The use of adsorbent storage media for natural gas (methane) vehicles allows for the use of non-cylindrical tanks due to the decreased pressure at which the natural gas is stored. The use of carbon powder as a storage material allows for a high mass of methane stored for mass of sample, but at the cost of the tank volume. Densified carbon monoliths, however, allow for the mass of methane for volume of tank to be optimized. In this work, different activated carbon monoliths have been produced using a polymeric binder, with various synthesis parameters. The methane storage was studied using a home-built, dosing-type instrument. A monolith with optimal parameters has been fabricated. The gravimetric excess adsorption for the optimized monolith was found to be 161 g methane for kg carbon.

  12. Methane storage in advanced porous materials.

    PubMed

    Makal, Trevor A; Li, Jian-Rong; Lu, Weigang; Zhou, Hong-Cai

    2012-12-01

    The need for alternative fuels is greater now than ever before. With considerable sources available and low pollution factor, methane is a natural choice as petroleum replacement in cars and other mobile applications. However, efficient storage methods are still lacking to implement the application of methane in the automotive industry. Advanced porous materials, metal-organic frameworks and porous organic polymers, have received considerable attention in sorptive storage applications owing to their exceptionally high surface areas and chemically-tunable structures. In this critical review we provide an overview of the current status of the application of these two types of advanced porous materials in the storage of methane. Examples of materials exhibiting high methane storage capacities are analyzed and methods for increasing the applicability of these advanced porous materials in methane storage technologies described.

  13. Thermal maturity and organic composition of Pennsylvanian coals and carbonaceous shales, north-central Texas: Implications for coalbed gas potential

    USGS Publications Warehouse

    Hackley, P.C.; Guevara, E.H.; Hentz, T.F.; Hook, R.W.

    2009-01-01

    Thermal maturity was determined for about 120 core, cuttings, and outcrop samples to investigate the potential for coalbed gas resources in Pennsylvanian strata of north-central Texas. Shallow (< 600??m; 2000??ft) coal and carbonaceous shale cuttings samples from the Middle-Upper Pennsylvanian Strawn, Canyon, and Cisco Groups in Archer and Young Counties on the Eastern Shelf of the Midland basin (northwest and downdip from the outcrop) yielded mean random vitrinite reflectance (Ro) values between about 0.4 and 0.8%. This range of Ro values indicates rank from subbituminous C to high volatile A bituminous in the shallow subsurface, which may be sufficient for early thermogenic gas generation. Near-surface (< 100??m; 300??ft) core and outcrop samples of coal from areas of historical underground coal mining in the region yielded similar Ro values of 0.5 to 0.8%. Carbonaceous shale core samples of Lower Pennsylvanian strata (lower Atoka Group) from two deeper wells (samples from ~ 1650??m; 5400??ft) in Jack and western Wise Counties in the western part of the Fort Worth basin yielded higher Ro values of about 1.0%. Pyrolysis and petrographic data for the lower Atoka samples indicate mixed Type II/Type III organic matter, suggesting generated hydrocarbons may be both gas- and oil-prone. In all other samples, organic material is dominated by Type III organic matter (vitrinite), indicating that generated hydrocarbons should be gas-prone. Individual coal beds are thin at outcrop (< 1??m; 3.3??ft), laterally discontinuous, and moderately high in ash yield and sulfur content. A possible analog for coalbed gas potential in the Pennsylvanian section of north-central Texas occurs on the northeast Oklahoma shelf and in the Cherokee basin of southeastern Kansas, where contemporaneous gas-producing coal beds are similar in thickness, quality, and rank.

  14. Biochemically enhanced methane production from coal

    NASA Astrophysics Data System (ADS)

    Opara, Aleksandra

    For many years, biogas was connected mostly with the organic matter decomposition in shallow sediments (e.g., wetlands, landfill gas, etc.). Recently, it has been realized that biogenic methane production is ongoing in many hydrocarbon reservoirs. This research examined microbial methane and carbon dioxide generation from coal. As original contributions methane production from various coal materials was examined in classical and electro-biochemical bench-scale reactors using unique, developed facultative microbial consortia that generate methane under anaerobic conditions. Facultative methanogenic populations are important as all known methanogens are strict anaerobes and their application outside laboratory would be problematic. Additional testing examined the influence of environmental conditions, such as pH, salinity, and nutrient amendments on methane and carbon dioxide generation. In 44-day ex-situ bench-scale batch bioreactor tests, up to 300,000 and 250,000 ppm methane was generated from bituminous coal and bituminous coal waste respectively, a significant improvement over 20-40 ppm methane generated from control samples. Chemical degradation of complex hydrocarbons using environmentally benign reagents, prior to microbial biodegradation and methanogenesis, resulted in dissolution of up to 5% bituminous coal and bituminous coal waste and up to 25% lignite in samples tested. Research results confirm that coal waste may be a significant underutilized resource that could be converted to useful fuel. Rapid acidification of lignite samples resulted in low pH (below 4.0), regardless of chemical pretreatment applied, and did not generate significant methane amounts. These results confirmed the importance of monitoring and adjusting in situ and ex situ environmental conditions during methane production. A patented Electro-Biochemical Reactor technology was used to supply electrons and electron acceptor environments, but appeared to influence methane generation in a

  15. The direct aromatization of methane

    SciTech Connect

    Marcelin, G.; Oukaci, R.; Migone, R.A.; Kazi, A.M.

    1995-12-31

    The thermal decomposition of methane shows significant potential as a process for the production of higher unsaturated and aromatic hydrocarbons when the extent of the reaction is limited. Thermodynamic calculations have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that cooling the product and reacting gases as the reaction proceeds can significantly reduce or eliminate the formation of solid carbon and heavier (C{sub 10+}) materials. Much work remains to be done in optimizing the quenching process and this is one of the goals of this program. Means to lower the temperature of the reaction are being studied as this result in a more feasible commercial process due to savings realized in energy and material of construction costs. The use of free-radical generators and catalysts will be investigated as a means of lowering the reaction temperature thus allowing faster quenching. It is highly likely that such studies will lead to a successful direct methane to higher hydrocarbon process.

  16. Methane emissions from Carex rostrata

    NASA Astrophysics Data System (ADS)

    Yelverton, C. A.; Varner, R. K.; Roddy, S.; Noyce, G. L.

    2013-12-01

    Peatlands, especially in northern regions, are known for their contribution to the increase of methane (CH4) in the atmosphere. Methane emissions from peatlands are strongly correlated with water table, temperature, and species composition. Sedges, in particular, are a conduit for the release of CH4 directly to the atmosphere. This study examines the impact of clipping and sealing sedges (Carex rostrata) on CH4 emissions from a temperate peatland (Sallie's Fen, Barrington, NH, USA). Measurements of CH4 fluxes, dissolved CH4, and environmental conditions were made over a six-year period. Data from 2008 to 2013 show that the presence of Carex rostrata in this peatland increases CH4 emissions. Clipped plots have both lower seasonal and annual CH4 emissions, compared to control plots. By studying the type of environment associated with C. rostrata through measurements of water-table depth, pore water characteristics, and the peat, surface, and air temperature of each surrounding location, further studies will show how these factors affect the rate at which CH4 is emitted into the atmosphere.

  17. Evaluation of Heat Induced Methane Release from Methane Hydrates

    NASA Astrophysics Data System (ADS)

    Leeman, J.; Elwood-Madden, M.; Phelps, T. J.; Rawn, C. J.

    2010-12-01

    Clathrates, or gas hydrates, structurally are guest gas molecules populating a cavity in a cage of water molecules. Gas hydrates naturally occur on Earth under low temperature and moderate pressure environments including continental shelf, deep ocean, and permafrost sediments. Large quantities of methane are trapped in hydrates, providing significant near-surface reserves of carbon and energy. Thermodynamics predicts that hydrate deposits may be destabilized by reducing the pressure in the system or raising the temperature. However, the rate of methane release due to varying environmental conditions remains relatively unconstrained and complicated by natural feedback effects of clathrate dissociation. In this study, hydrate dissociation in sediment due to localized increases in temperature was monitored and observed at the mesoscale (>20L) in a laboratory environment. Experiments were conducted in the Seafloor Process Simulator (SPS) at Oak Ridge National Laboratory (ORNL) to simulate heat induced dissociation. The SPS, containing a column of Ottawa sand saturated with water containing 25mg/L Sno-Max to aid nucleation, was pressurized and cooled well into the hydrate stability field. A fiber optic distributed sensing system (DSS) was embedded at four depths in the sediment column. This allowed the temperature strain value (a proxy for temperature) of the system to be measured with high spatial resolution to monitor the clathrate formation/dissociation processes. A heat exchanger embedded in the sediment was heated using hot recirculated ethylene glycol and the temperature drop across the exchanger was measured. These experiments indicate a significant and sustained amount of heat is required to release methane gas from hydrate-bearing sediments. Heat was consumed by hydrate dissociated in a growing sphere around the heat exchanger until steady state was reached. At steady state all heat energy entering the system was consumed in maintaining the temperature profile

  18. Identification of Methanogens and Controls on Methane Production in Incubations of Natural Methane Seep Sediments

    NASA Astrophysics Data System (ADS)

    Kevorkian, R.; Lloyd, K. G.

    2014-12-01

    Methane, the most abundant hydrocarbon in Earth's atmosphere, is produced in large quantities in sediments underlying the world's oceans. Very little of this methane makes it to surface sediments as it is consumed by Anaerobic Methanotrophs (ANME's) in consortia with Sulfate Reducing Bacteria (SRB). Less is known about which organisms are responsible for methane production in marine sediments, and whether that production is under thermodynamic control based on hydrogen concentrations. Although ANMEs have been found to be active in methanogenic sediments and incubations, it is currently unknown whether they are able to grow in methanogenic conditions. We demonstrated with bottle incubations of methane seep sediment taken from Cape Lookout Bight, NC, that hydrogen controls methane production. While sulfate was present the hydrogen concentration was maintained at below 2 nM. Only after the depletion of sulfate allowed hydrogen concentrations to rise above 5 nM did we see production of methane. The same sediments when spiked with methane gas demonstrated its complete removal while sulfate reduction occurred. Quantitative PCR shows that ANME-2 and ANME-1 increase in 16S copy number as methane increases. Total direct cell counts demonstrate a decline in cells with the decrease of sulfate until a recovery corresponding with production of methane. Our results strongly suggest that hydrogen concentrations influence what metabolic processes can occur in marine sediments, and that ANME-1 and ANME-2 are able to grow on the energy provided from methane production.

  19. Stable methane hydrate above 2 GPa and the source of Titan's atmospheric methane.

    PubMed

    Loveday, J S; Nelmes, R J; Guthrie, M; Belmonte, S A; Allan, D R; Klug, D D; Tse, J S; Handa, Y P

    2001-04-01

    Methane hydrate is thought to have been the dominant methane-containing phase in the nebula from which Saturn, Uranus, Neptune and their major moons formed. It accordingly plays an important role in formation models of Titan, Saturn's largest moon. Current understanding assumes that methane hydrate dissociates into ice and free methane in the pressure range 1-2 GPa (10-20 kbar), consistent with some theoretical and experimental studies. But such pressure-induced dissociation would have led to the early loss of methane from Titan's interior to its atmosphere, where it would rapidly have been destroyed by photochemical processes. This is difficult to reconcile with the observed presence of significant amounts of methane in Titan's present atmosphere. Here we report neutron and synchrotron X-ray diffraction studies that determine the thermodynamic behaviour of methane hydrate at pressures up to 10 GPa. We find structural transitions at about 1 and 2 GPa to new hydrate phases which remain stable to at least 10 GPa. This implies that the methane in the primordial core of Titan remained in stable hydrate phases throughout differentiation, eventually forming a layer of methane clathrate approximately 100 km thick within the ice mantle. This layer is a plausible source for the continuing replenishment of Titan's atmospheric methane. PMID:11287946

  20. Root-Associated Methane Oxidation and Methanogenesis: Key Determinants of Wetland Methane Emissions

    NASA Technical Reports Server (NTRS)

    King, G. M.

    1997-01-01

    During the award period, we have assessed the extent and controls of methane oxidation in north temperate wetlands. It is evident that wetlands have been a major global source of atmospheric methane in the past, and are so at present. It is also evident that microbial methane oxidation consumes a variable fraction of total wetland methane production, perhaps 10%-90%. Methane oxidation is thus a potentially important control of wetland methane emission. Our efforts have been designed to determine the extent of the process, its controls, and possible relationships to changes that might be expected in wetlands as a consequence of anthropogenic or climate-related disturbances. Current work, has emphasized controls of methane oxidation associated with rooted aquatic plants. As for the sediment-water interface, we have observed that oxygen availability is a primary limiting factor. Our conclusion is based on several different lines of evidence obtained from in vitro and in situ analyses. First, we have measured the kinetics of methane oxidation by intact plant roots harboring methane-oxidizing bacteria, as well as the kinetics of the methanotrophs themselves. Values for the half-saturation constant (apparent K(sub m)) are approximately 5 microns. These values are roughly equivalent to, or much less than porewater methane concentrations, indicating that uptake is likely saturated with respect to methane, and that some other parameter must limit activity. Methane concentrations in the lacunar spaces at the base of plant stems are also comparable to the half-saturation constants (when expressed as equivalent dissolved concentrations), providing further support for limitation of uptake by parameters other than methane.

  1. Environmental factors affecting methane distribution and bacterial methane oxidation in the German Bight (North Sea)

    NASA Astrophysics Data System (ADS)

    Osudar, Roman; Matoušů, Anna; Alawi, Mashal; Wagner, Dirk; Bussmann, Ingeborg

    2015-07-01

    River estuaries are responsible for high rates of methane emissions to the atmosphere. The complexity and diversity of estuaries require detailed investigation of methane sources and sinks, as well as of their spatial and seasonal variations. The Elbe river estuary and the adjacent North Sea were chosen as the study site for this survey, which was conducted from October 2010 to June 2012. Using gas chromatography and radiotracer techniques, we measured methane concentrations and methane oxidation (MOX) rates along a 60 km long transect from Cuxhaven to Helgoland. Methane distribution was influenced by input from the methane-rich mouth of the Elbe and gradual dilution by methane-depleted sea water. Methane concentrations near the coast were on average 30 ± 13 nmol L-1, while in the open sea, they were 14 ± 6 nmol L-1. Interestingly, the highest methane concentrations were repeatedly detected near Cuxhaven, not in the Elbe River freshwater end-member as previously reported. Though, we did not find clear seasonality we observed temporal methane variations, which depended on temperature and presumably on water discharge from the Elbe River. The highest MOX rates generally coincided with the highest methane concentrations, and varied from 2.6 ± 2.7 near the coast to 0.417 ± 0.529 nmol L-1 d-1 in the open sea. Turnover times varied from 3 to >1000 days. MOX rates were strongly affected by methane concentration, temperature and salinity. We ruled out the supposition that MOX is not an important methane sink in most of the Elbe estuary and adjacent German Bight.

  2. 30 CFR 75.1324 - Methane concentration and tests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Methane concentration and tests. 75.1324... Methane concentration and tests. (a) No shot shall be fired in an area that contains 1.0 volume percent or more of methane. (b) Immediately before shots are fired, the methane concentration in a working...

  3. 30 CFR 75.1324 - Methane concentration and tests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Methane concentration and tests. 75.1324... Methane concentration and tests. (a) No shot shall be fired in an area that contains 1.0 volume percent or more of methane. (b) Immediately before shots are fired, the methane concentration in a working...

  4. 30 CFR 75.1324 - Methane concentration and tests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Methane concentration and tests. 75.1324... Methane concentration and tests. (a) No shot shall be fired in an area that contains 1.0 volume percent or more of methane. (b) Immediately before shots are fired, the methane concentration in a working...

  5. 30 CFR 75.1324 - Methane concentration and tests.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Methane concentration and tests. 75.1324... Methane concentration and tests. (a) No shot shall be fired in an area that contains 1.0 volume percent or more of methane. (b) Immediately before shots are fired, the methane concentration in a working...

  6. 30 CFR 75.1324 - Methane concentration and tests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Methane concentration and tests. 75.1324... Methane concentration and tests. (a) No shot shall be fired in an area that contains 1.0 volume percent or more of methane. (b) Immediately before shots are fired, the methane concentration in a working...

  7. 30 CFR 75.323 - Actions for excessive methane.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Actions for excessive methane. 75.323 Section... excessive methane. (a) Location of tests. Tests for methane concentrations under this section shall be made.... (1) When 1.0 percent or more methane is present in a working place or an intake air course,...

  8. 30 CFR 75.323 - Actions for excessive methane.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions for excessive methane. 75.323 Section... excessive methane. (a) Location of tests. Tests for methane concentrations under this section shall be made.... (1) When 1.0 percent or more methane is present in a working place or an intake air course,...

  9. 30 CFR 27.21 - Methane-monitoring system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Methane-monitoring system. 27.21 Section 27.21... APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.21 Methane-monitoring system. (a) A methane-monitoring system shall be so designed that any machine or equipment,...

  10. 30 CFR 75.323 - Actions for excessive methane.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Actions for excessive methane. 75.323 Section... excessive methane. (a) Location of tests. Tests for methane concentrations under this section shall be made.... (1) When 1.0 percent or more methane is present in a working place or an intake air course,...

  11. 30 CFR 27.21 - Methane-monitoring system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Methane-monitoring system. 27.21 Section 27.21... APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.21 Methane-monitoring system. (a) A methane-monitoring system shall be so designed that any machine or equipment,...

  12. 30 CFR 27.21 - Methane-monitoring system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Methane-monitoring system. 27.21 Section 27.21... APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.21 Methane-monitoring system. (a) A methane-monitoring system shall be so designed that any machine or equipment,...

  13. Methane cycling in a tidal freshwater swamp

    SciTech Connect

    Megonigal, J.P.; Schlesinger, W.H. )

    1993-06-01

    Previous studies of methanogenesis in a tidal freshwater swamp on the North Carolina coast have found that potential rates of methane production overestimate observed rates of methane flux, especially during summer months. This research investigates three possibilities for the unexplained losses: methane oxidation, lateral export of dissolved methane to the adjacent river, and ebullition. It is possible that each of these sinks increase during the summer. The potential for methane oxidation was demonstrated in intact soil cores incubated for 21 hours under a 0.5% CH[sub 3]F atmosphere. Methane flux increased from 10+/-27 (mean+/-sd) to 60+/-3 mg m[sup [minus]2] d[sup [minus]1] in treated cores; control core fluxes were 15+/-3 and 19+/-3 mg m[sup [minus]2] d[sup [minus]1] over the same periods. Incubations of slightly unsaturated soils with [sup 14]CH[sub 4] confirmed rapid potential rates of methane oxidation.

  14. Liquid Ethane and Methane on Titan

    NASA Astrophysics Data System (ADS)

    Clark, Roger Nelson; Curchin, J.; Brown, R. H.; Barnes, J. W.; Jaumann, R.; Soderblom, L.; Cruikshank, D. P.; Lunine, J.; Stephan, K.; Hoefen, T. H.; Le Mouelic, S.; Sotin, C.; Baines, K.; Buratti, B.; Nicholson, P.

    2008-09-01

    Absorption coefficients for liquid methane and ethane were derived in a 1-bar nitrogen atmosphere at 90K. Ethane and methane were condensed in an aluminum sample cup, and a 2-way transmission spectrum was measured. Different path lengths up to 14 mm allowed a wide range of absorption coefficients to be measured, and covered the range needed to compare to spectra of Titan in the 1- to 5-micron atmospheric windows. The data were used to compute possible liquid absorption in spectra from the Cassini Visual and Infrared Mapping Spectrometer (VIMS) and were compared to global VIMS data for Titan. The laboratory data show that both liquid methane and ethane have a strong absorption band near 4.97 microns that is detectable by VIMS. A liquid lake thickness of 3 mm (6 mm path length) would result in an absorption band depth of about 65% for methane and 85% for ethane. Ethane has a 2.02-micron absorption with a strength similar to the 4.97-micron absorption, and methane has an absorption that is 10x weaker. Continuum absorption would result in the following surface reflectance levels (at VIMS wavelengths and resolution). Examining VIMS Titan data, we find that for most of the surface, we detect no liquid methane or ethane. In a few locations VIMS data indicate liquid methane or ethane, but at less than about 1-mm total path length.

  15. Methane on Mars: Measurements and Possible Origins

    NASA Technical Reports Server (NTRS)

    Mumma, Michael J.; Villanueva, Geronimo L.; Novak, Robert E.; Radeva, Yana L.; Kaufl, H. Ulrich; Tokunaga, Alan; Encrenaz, Therese; Hartogh, Paul

    2011-01-01

    The presence of abundant methane in Earth's atmosphere (1.6 parts per million) requires sources other than atmospheric chemistry. Living systems produce more than 90% of Earth's atmospheric methane; the balance is of geochemical origin. On Mars, methane has been sought for nearly 40 years because of its potential biological significance, but it was detected only recently [1-5]. Its distribution on the planet is found to be patchy and to vary with time [1,2,4,5], suggesting that methane is released recently from the subsurface in localized areas, and is then rapidly destroyed [1,6]. Before 2000, searchers obtained sensitive upper limits for methane by averaging over much of Mars' dayside hemisphere, using data acquired by Marsorbiting spacecraft (Mariner 9) and Earth-based observatories (Kitt Peak National Observatory, Canada- France-Hawaii Telescope, Infrared Space Observatory). These negative findings suggested that methane should be searched at higher spatial resolution since the local abundance could be significantly larger at active sites. Since 2001, searches for methane have emphasized spatial mapping from terrestrial observatories and from Mars orbit (Mars Express).

  16. Treating Coalbed Natural Gas Produced Water for Beneficial Use By MFI Zeolite Membranes

    SciTech Connect

    Robert Lee; Liangxiong Li

    2008-03-31

    Desalination of brines produced from oil and gas fields is an attractive option for providing potable water in arid regions. Recent field-testing of subsurface sequestration of carbon dioxide for climate management purposes provides new motivation for optimizing efficacy of oilfield brine desalination: as subsurface reservoirs become used for storing CO{sub 2}, the displaced brines must be managed somehow. However, oilfield brine desalination is not economical at this time because of high costs of synthesizing membranes and the need for sophisticated pretreatments to reduce initial high TDS and to prevent serious fouling of membranes. In addition to these barriers, oil/gas field brines typically contain high concentrations of multivalent counter cations (eg. Ca{sup 2+} and SO{sub 4}{sup 2-}) that can reduce efficacy of reverse osmosis (RO). Development of inorganic membranes with typical characteristics of high strength and stability provide a valuable option to clean produced water for beneficial uses. Zeolite membranes have a well-defined subnanometer pore structure and extreme chemical and mechanical stability, thus showing promising applicability in produced water purification. For example, the MFI-type zeolite membranes with uniform pore size of {approx}0.56 nm can separate ions from aqueous solution through a mechanism of size exclusion and electrostatic repulsion (Donnan exclusion). Such a combination allows zeolite membranes to be unique in separation of both organics and electrolytes from aqueous solutions by a reverse osmosis process, which is of great interest for difficult separations, such as oil-containing produced water purification. The objectives of the project 'Treating Coalbed Natural Gas Produced Water for Beneficial Use by MFI Zeolite Membranes' are: (1) to conduct extensive fundamental investigations and understand the mechanism of the RO process on zeolite membranes and factors determining the membrane performance, (2) to improve the

  17. Methane venting to the atmosphere from sediments

    NASA Astrophysics Data System (ADS)

    Shakhova, Natalia; Semiletov, Igor; Salyuk, Anatoly; Joussupov, Vladimir; Kosmach, Denis; Gustafsson, Orjan; Leifer, Ira

    2010-05-01

    Sustained release of methane to the atmosphere from thawing Arctic permafrost likely is a strong positive feedback to climate warming. A climate impact of Arctic methane releases is implied by past climate shifts and may play a role in the renewed growth of contemporary atmospheric methane. Observed Arctic warming in early 21st century is stronger than predicted by several degrees, which may accelerate thaw-release of methane. The East Siberian Arctic Shelf (ESAS, encompassing the Laptev, East Siberian and Russian part of the Chuckchi Seas) occupies an area of 2.1×106 km2, three times as great as terrestrial Siberian wetlands. It is a shallow seaward extension of the Siberian tundra that was flooded during the Holocene transgression 7-15 kyr ago. The ESAS sub-sea permafrost, (frozen sediments inter-layered with the flooded peatland) contains not only comparable amounts of carbon as still land-fast permafrost in the Siberian tundra, but also sequesters permafrost-related seabed deposits of CH4. Remobilization to the atmosphere of only a small fraction of the methane trapped in ESAS sediments could trigger abrupt climate warming. Currently it is hypothesized that sub-sea permafrost acts as a lid retaining this shallow methane reservoir. However, estimates of ESAS methane emissions based on recent observations indicate the current atmospheric budget, which arises from gradual diffusion and ebullition, is on par with estimates of methane emissions from the entire World Ocean. Large transient emissions remain to be assessed; yet initial data suggest this component could increase significantly annual emissions. These study results show methane leakage from the shallow ESAS needs consideration in interactions between the biogeosphere and a warming Arctic climate.

  18. Anaerobic methane oxidation on the Amazon shelf

    SciTech Connect

    Blair, N.E.; Aller, R.C.

    1995-09-01

    Anaerobic methane oxidation on the Amazon shelf is strongly controlled by dynamic physical sedimentation processes. Rapidly accumulating, physically reworked deltaic sediments characteristic of much of the shelf typically support what appear to be low rates of steady state anaerobic methane oxidation at depths of 5-8 m below the sediment-water interface. Methane oxidation in these cases is responsible for < {approximately}10% of the {Sigma}CO{sub 2} inventory in the oxidation zone and is limited largely by the steady-state diffusive flux of methane into the overlying sulfate reduction zone. In contrast, a large area of the shelf has been extensively eroded, reexposing once deeply buried (>10 m) methane-charged sediment directly to seawater. In this nonsteady-state situation, methane is a major source of recently produced {Sigma}CO{sub 2} and an important reductant for sulfate. These observations suggest that authigenic sedimentary carbonates derived from anaerobic methane oxidation may sometimes reflect physically enhanced nonsteady-state exposure of methane to sulfate in otherwise biogeochemically unreactive deposits. The concentration profiles of CH{sub 4}, SO{sub 4}{sup =}, and {Sigma}CO{sub 2} in the eroded deposit were reproduced by a coupled reaction-transport model. This area of the shelf was reexposed to seawater approximately 5-10 years ago based on the model results and the assumption that the erosion of the deposit occurred as a single event that has now ceased. The necessary second order rate constant for anaerobic methane oxidation was {le}0.1 mM{sup -1} d{sup -1}.

  19. Mars Methane highs unrelated to comets

    NASA Astrophysics Data System (ADS)

    Roos-Serote, Maarten; Atreya, Sushil K.; Webster, Chris; Mahaffy, Paul

    2016-10-01

    Until the Curiosity Rover arrived at Mars, all measurements of methane were done by remote sensing, either from Earth or from orbiting spacecraft, using a variety of different instruments and under different observing conditions. The Curiosity Rover's Sample Analysis at Mars (SAM) / Tunable Laser Spectrometer (TLS) has carried out systematic measurements of martian methane from Gale crater for two consecutive martian years (31 - 33, starting in October 2012). Meteoric material interacts with the martian atmosphere when Mars passes through a meteoroid stream left behind by cometary bodies orbiting the Sun. Predictions show that 33 such events are likely to occur during the martian year. It has been suggested that the organics present in this material trigger the formation of methane in the atmosphere, and thus these events could possibly be an explanation for the observed variations in the methane abundance. In a recent paper, Fries et al. [2016] argued that all measurements of high methane concentrations are within 16 days of a predicted meteor shower event, and that as such there is a correlation. We present a new analysis including seven new data points that were not available previously. All these new measurements show low methane values. Some of the new measurements were deliberately taken at the same Ls when high values of methane were measured in the previous martian year, showing that the high methane measurements are likely not seasonal, as would be expected if they were connected to meteor shower events. In our analysis we take into account all the predicted meteor events and search for any correlation drawn between these events and the level of methane in the atmosphere. We conclude that whether we consider individual data points, apply statistical analysis, or consider different time spans between measurements and the occurrence of meteor events, or possible supply of organic material from comets, there is no evidence for such a correlation in the

  20. Experiments on Methane Displacement by Carbon Dioxide in Large Coal Specimens

    NASA Astrophysics Data System (ADS)

    Liang, Weiguo; Zhao, Yangsheng; Wu, Di; Dusseault, Maurice B.

    2011-09-01

    changes in the microstructure of the coal itself. Artificial stimulation (e.g. hydraulic fracturing) to improve coalbed transport properties for either CO2 sequestration or enhanced coal bed methane recovery will be necessary. The interactions of large-scale induced fractures with the fabric at the scale of observable fissures and fractures in the laboratory specimens, as well as to the pore scale processes associated with adsorption and desorption, remain of profound interest and a great challenge.

  1. Measuring Methane Production from Ruminants.

    PubMed

    Hill, Julian; McSweeney, Chris; Wright, André-Denis G; Bishop-Hurley, Greg; Kalantar-Zadeh, Kourosh

    2016-01-01

    Radiative forcing of methane (CH4) is significantly higher than carbon dioxide (CO2) and its enteric production by ruminant livestock is one of the major sources of greenhouse gas emissions. CH4 is also an important marker of farming productivity, because it is associated with the conversion of feed to product in livestock. Consequently, measurement of enteric CH4 is emerging as an important research topic. In this review, we briefly describe the conversion of carbohydrate to CH4 by the bacterial community within gut, and highlight some of the key host-microbiome interactions. We then provide a picture of current progress in techniques for measuring enteric CH4, the context in which these technologies are used, and the challenges faced. We also discuss solutions to existing problems and new approaches currently in development.

  2. Measuring Methane Production from Ruminants.

    PubMed

    Hill, Julian; McSweeney, Chris; Wright, André-Denis G; Bishop-Hurley, Greg; Kalantar-Zadeh, Kourosh

    2016-01-01

    Radiative forcing of methane (CH4) is significantly higher than carbon dioxide (CO2) and its enteric production by ruminant livestock is one of the major sources of greenhouse gas emissions. CH4 is also an important marker of farming productivity, because it is associated with the conversion of feed to product in livestock. Consequently, measurement of enteric CH4 is emerging as an important research topic. In this review, we briefly describe the conversion of carbohydrate to CH4 by the bacterial community within gut, and highlight some of the key host-microbiome interactions. We then provide a picture of current progress in techniques for measuring enteric CH4, the context in which these technologies are used, and the challenges faced. We also discuss solutions to existing problems and new approaches currently in development. PMID:26603286

  3. Methane Pyrolysis and Disposing Off Resulting Carbon

    NASA Technical Reports Server (NTRS)

    Sharma, P. K.; Rapp, D.; Rahotgi, N. K.

    1999-01-01

    Sabatier/Electrolysis (S/E) is a leading process for producing methane and oxygen for application to Mars ISPP. One significant problem with this process is that it produces an excess of methane for combustion with the amount of oxygen that is produced. Therefore, one must discard roughly half of the methane to obtain the proper stoichiometric methane/oxygen mixture for ascent from Mars. This is a waste of hydrogen, which must be brought from Earth and is difficult to transport to Mars and store on Mars. To reduce the problem of transporting hydrogen to Mars, the S/E process can be augmented by another process which reduces overall hydrogen requirement. Three conceptual approaches for doing this are (i) recover hydrogen from the excess methane produced by the S/E process, (ii) convert the methane to a higher hydrocarbon or other organic with a lower H/C ratio than methane, and (iii) use a separate process (such as zirconia or reverse water gas shift reaction) to produce additional oxygen, thus utilizing all the methane produced by the Sabatier process. We report our results here on recovering hydrogen from the excess methane using pyrolysis of methane. Pyrolysis has the advantage that it produces almost pure hydrogen, and any unreacted methane can pass through the S/E process reactor. It has the disadvantage that disposing of the carbon produced by pyrolysis presents difficulties. The goals of a research program on recovery of hydrogen from methane are (in descending priority order): 1) Study the kinetics of pyrolysis to arrive at a pyrolysis reactor design that produces high yields in a confined volume at the lowest possible operating temperature; 2) Study the kinetics of carbon burnoff to determine whether high yields can be obtained in a confined volume at acceptable operating temperatures; and 3) Investigate catalytic techniques for depositing carbon as a fine soot which can be physically separated from the reactor. In the JPL program, we have made significant

  4. Tapping methane hydrates for unconventional natural gas

    USGS Publications Warehouse

    Ruppel, Carolyn

    2007-01-01

    Methane hydrate is an icelike form of concentrated methane and water found in the sediments of permafrost regions and marine continental margins at depths far shallower than conventional oil and gas. Despite their relative accessibility and widespread occurrence, methane hydrates have never been tapped to meet increasing global energy demands. With rising natural gas prices, production from these unconventional gas deposits is becoming economically viable, particularly in permafrost areas already being exploited for conventional oil and gas. This article provides an overview of gas hydrate occurrence, resource assessment, exploration, production technologies, renewability, and future challenges.

  5. METHOD FOR PRODUCING ISOTOPIC METHANES AND PARTIALLY HALOGENATED DERIVATIVES THEROF

    DOEpatents

    Frazer, J.W.

    1959-08-18

    A method is given for producing isotopic methanes and/ or partially halogenated derivatives. Lithium hydride, deuteride, or tritide is reacted with a halogenated methane or with a halogenated methane in combination with free halogen. The process is conveniently carried out by passing a halogenated methane preferably at low pressures or in an admixture with an inert gas through a fixed bed of finely divided lithium hydride heated initially to temperatures of 100 to 200 deg C depending upon the halogenated methane used.

  6. Methane metabolism in a temperate swamp

    SciTech Connect

    Amaral, J.A.; Knowles, R.

    1994-11-01

    Methane production has received much attention due not only to its importance as a terminal step in anaerobic organic matter degradation but also to its potentially significant role in climatic change and atmospheric chemistry. Wetlands are an important source and potential reservoir of methane, but the factors controlling its production and emission are not fully understood. This study examined in situ availability of substrates and the distribution of electron acceptors in a temperate peat swamp to determine how the chemistry and microbiology of the site affects methane production. Measurements were obtained in summer, fall and spring at two sites. Laboratory incubations with slurried peat soil were carried out. From the results, the authors speculate that along with differences in hydrology and chemical characteristics, heterogeneity in microbial activity may also contribute to the spatial variability of methane production and emission in wetlands. 45 refs., 6 figs., 4 tabs.

  7. Producing Hydrogen by Plasma Pyrolysis of Methane

    NASA Technical Reports Server (NTRS)

    Atwater, James; Akse, James; Wheeler, Richard

    2010-01-01

    Plasma pyrolysis of methane has been investigated for utility as a process for producing hydrogen. This process was conceived as a means of recovering hydrogen from methane produced as a byproduct of operation of a life-support system aboard a spacecraft. On Earth, this process, when fully developed, could be a means of producing hydrogen (for use as a fuel) from methane in natural gas. The most closely related prior competing process - catalytic pyrolysis of methane - has several disadvantages: a) The reactor used in the process is highly susceptible to fouling and deactivation of the catalyst by carbon deposits, necessitating frequent regeneration or replacement of the catalyst. b) The reactor is highly susceptible to plugging by deposition of carbon within fixed beds, with consequent channeling of flow, high pressure drops, and severe limitations on mass transfer, all contributing to reductions in reactor efficiency. c) Reaction rates are intrinsically low. d) The energy demand of the process is high.

  8. Methane Detector With Plastic Fresnel Lens

    NASA Technical Reports Server (NTRS)

    Grant, W. B.

    1986-01-01

    Laser detector for natural gas leaks modified by substitution of molded plastic lens for spherical mirror. By measuring relative attenuation at two wavelengths, detector used to check for methane escaping from pipelines above or below ground and from landfill.

  9. Formation temperatures of thermogenic and biogenic methane

    USGS Publications Warehouse

    Stolper, D.A.; Lawson, M.; Davis, C.L.; Ferreira, A.A.; Santos Neto, E. V.; Ellis, G.S.; Lewan, M.D.; Martini, A.M.; Tang, Y.; Schoell, M.; Sessions, A.L.; Eiler, J.M.

    2014-01-01

    Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models.

  10. Aerodyne Research mobile infrared methane monitor

    NASA Technical Reports Server (NTRS)

    Mcmanus, J. B.; Kebabian, P. L.; Kolb, C. E.

    1991-01-01

    An improved real-time methane monitor based on infrared absorption of the 3.39 micron line of a HeNe laser is described. Real time in situ measurement of methane has important applications in stratospheric and tropospheric chemistry, especially when high accuracy measurements can be made rapidly, providing fine spatial-scale information. The methane instrument provides 5 ppb resolution in a 1 sec averaging time. A key feature in this instrument is the use of magnetic (Zeeman) broadening to achieve continuous tunability with constant output power over a range of 0.017/cm. The instruments optical absorption path length is 47 m through sampled air held at 50 torr in a multipass cell of the Herriott (off-axis resonator) type. A microprocessor controls laser frequency and amplitude and collects data with minimal operator attention. The instrument recently has been used to measure methane emissions from a variety of natural and artificial terrestrial sources.

  11. Abiotic Production of Methane in Terrestrial Planets

    PubMed Central

    Guzmán-Marmolejo, Andrés; Escobar-Briones, Elva

    2013-01-01

    Abstract On Earth, methane is produced mainly by life, and it has been proposed that, under certain conditions, methane detected in an exoplanetary spectrum may be considered a biosignature. Here, we estimate how much methane may be produced in hydrothermal vent systems by serpentinization, its main geological source, using the kinetic properties of the main reactions involved in methane production by serpentinization. Hydrogen production by serpentinization was calculated as a function of the available FeO in the crust, given the current spreading rates. Carbon dioxide is the limiting reactant for methane formation because it is highly depleted in aqueous form in hydrothermal vent systems. We estimated maximum CH4 surface fluxes of 6.8×108 and 1.3×109 molecules cm−2 s−1 for rocky planets with 1 and 5 M⊕, respectively. Using a 1-D photochemical model, we simulated atmospheres with volume mixing ratios of 0.03 and 0.1 CO2 to calculate atmospheric methane concentrations for the maximum production of this compound by serpentinization. The resulting abundances were 2.5 and 2.1 ppmv for 1 M⊕ planets and 4.1 and 3.7 ppmv for 5 M⊕ planets. Therefore, low atmospheric concentrations of methane may be produced by serpentinization. For habitable planets around Sun-like stars with N2-CO2 atmospheres, methane concentrations larger than 10 ppmv may indicate the presence of life. Key Words: Serpentinization—Exoplanets—Biosignatures—Planetary atmospheres. Astrobiology 13, 550–559. PMID:23742231

  12. The Clumped Isotope Composition of Biogenic Methane.

    NASA Astrophysics Data System (ADS)

    Sessions, A. L.; Douglas, P. M.; Eiler, J. M.; Stolper, D. A.

    2015-12-01

    The excess or lack of 13CH3D, a doubly substituted ("clumped") isotopologue of methane, relative to that expected for a random distribution of isotopes across molecules, is a function of the processes that generated the methane. For high-temperature thermogenic methane, which typically achieves internal equilibrium, an excess of 13CH3D is expected and the amount of excess can serve as a thermometer. In contrast, biogenic methane often - though not always - has a smaller excess of clumped isotopologues, and sometimes even a deficit of clumped species ("anti-clumped"). The effect presumably arises from kinetic isotope effects accompanying enzymatic reactions in the methanogenic pathway, though the particular reaction(s) has not yet been positively identified. The decrease in clumping is also known to correlate with both the reversibility of the pathway and the methane flux. In this talk, we will present recent data bearing on the origin and utility of biologic fractionations of clumped isotopologues in methane. Preliminary data suggest that methane deriving from the fermentative pathway is enriched in D-bearing isotopologues, at the same level of clumping, relative to that derived from the CO2-reductive pathway. This property offers another potential means to distinguish biogenic methane sources in the environment. Recently, we have also begun to measure the 12CH2D2 isotopologue, for which equilibrium and kinetic isotope effects are predicted to be distinct from 13CH3D. Preliminary data suggest that the combination of both doubly-substituted isotopologues will be especially useful for disentangling mixtures containing biogenic gas.

  13. Methane Fingerprinting: Isotopic Methane and Ethane-to-Methane Ratio Analysis Using a Cavity Ring-Down Spectrometer

    NASA Astrophysics Data System (ADS)

    Saad, Nabil; Fleck, Derek; Hoffnagle, John

    2016-04-01

    Emissions of Natural gas, and methane (CH4) specifically, have come under increased scrutiny by virtue of methane's 28-36x greenhouse warming potential compared to carbon dioxide (CO2) while accounting for 10% of the total greenhouse gas emissions in the US. Large uncontrolled leaks, such as the recent Aliso Canyon leak, originating from uncapped wells, coal mines and storage facilities have increased the total global contribution of methane missions even further. Determining the specific fingerprint of methane sources, by quantifying δ13C values and C2:C1 ratios, provides the means to understand methane producing processes and allows for sources of methane to be mapped and classified through these processes; i.e. biogenic vs. thermogenic, wet vs dry. In this study we present a fully developed Cavity Ring-Down Spectrometer (CRDS) that precisely measures 12CH4 concentration and its 13CH4 isotope concentration, yielding δ13C measurements, C2H6 concentration, along with CO2 and H2O. This provides real-time continuous measurements without an upfront separation requirement or multiple analyses to derive the origin of the gas samples. The highly sensitive analyzer allows for measurements of scarce molecules down to sub-ppb 1-σ precision in 5 minutes of measurement: with CH4 <0.1ppb, δ13C <1‰ C2H6 <1ppb and CO2 <1ppm. To complement this work, we provide the analysis of different methane sources providing a 2-dimensional mapping of methane sources as functions of δ13C and C2:C1 ratios, which can be thought of as a modified Bernard Plot. This dual ratio mapping can be used to discriminate between naturally occurring biogenic methane sources, naturally occurring enriched thermogenic sources, and natural gas distribution sources. This also shows future promise in aiding gas and oil exploration, in distinguishing oil vs coal gases, as well as a valuable tool in the development of methane sequestration.

  14. Methane emission by adult ostriches (Struthio camelus).

    PubMed

    Frei, Samuel; Dittmann, Marie T; Reutlinger, Christoph; Ortmann, Sylvia; Hatt, Jean-Michel; Kreuzer, Michael; Clauss, Marcus

    2015-02-01

    Ostriches (Struthio camelus) are herbivorous birds with a digestive physiology that shares several similarities with that of herbivorous mammals. Previous reports, however, claimed a very low methane emission from ostriches, which would be clearly different from mammals. If this could be confirmed, ostrich meat would represent a very attractive alternative to ruminant-and generally mammalian-meat by representing a particularly low-emission agricultural form of production. We individually measured, by chamber respirometry, the amount of oxygen consumed as well as carbon dioxide and methane emitted from six adult ostriches (body mass 108.3±8.3 kg) during a 24-hour period when fed a pelleted lucerne diet. While oxygen consumption was in the range of values previously reported for ostriches, supporting the validity of our experimental setup, methane production was, at 17.5±3.2 L d(-1), much higher than previously reported for this species, and was of the magnitude expected for similar-sized, nonruminant mammalian herbivores. These results suggest that methane emission is similar between ostriches and nonruminant mammalian herbivores and that the environmental burden of these animals is comparable. The findings furthermore indicate that it appears justified to use currently available scaling equations for methane production of nonruminant mammals in paleo-reconstructions of methane production of herbivorous dinosaurs.

  15. Climate reconstruction from a methane influenced environment

    NASA Astrophysics Data System (ADS)

    Sztybor, K.; Rasmussen, T. L.; Mienert, J.; Bunz, S.; Consolaro, C.

    2013-12-01

    Sediment cores have been collected from Vestnesa Ridge, western Svalbard margin, from within and outside an active pockmark with methane gas flares. The lithological log, X-ray, magnetic susceptibility and numerous AMS dates were used to constrain the age model and for high-resolution inter-core correlation. Other proxies used in order to reconstruct the dynamics of changes of bottom water properties as well as North Atlantic hydrography were oxygen and carbon isotopes of benthic and planktonic foraminifera and assemblage counts. The main purpose of the study is to resolve the frequency of CH4 emissions from the seafloor through time in relation to past climate change. The magnetic susceptibility record from the pockmark core shows very low and constant values without the pattern typical for the western Svalbard. The seeping of methane clearly destroyed the signal. Benthic foraminifera within several intervals are depleted in δ13C, indicating increased methane flux from the seafloor. Carbon isotope values measured in planktonic foraminifera shells are also extremely low (<-10 ‰), which can be caused by coating of AOM (Anaerobic oxidation of methane)-derived carbonates (authigenic overgrowth). Moreover methane seepage affects the outcomes of AMS dating. Our results suggest that radiocarbon dates measured in bivalve shells are approximately 3000 cal years too old. In a methane influenced environment a multiproxy approach is necessary for more accurate paleoclimate reconstructions.

  16. Airborne Methane Measurements using Optical Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Riris, H.; Numata, K.; Li, S.; Wu, S.; Ramanathan, A.; Dawsey, M.; Abshire, J. B.; Kawa, S. R.; Mao, J.

    2012-12-01

    We report on airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from clathrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment and more measurements are needed. In this paper we report on an airborne demonstration of atmospheric methane column optical depth measurements at 1.65 μm using widely tunable, seeded optical parametric amplifier (OPA) and a photon counting detector. Our results show good agreement between the experimentally derived optical depth measurements and theoretical calculations and follow the expected changes for aircraft altitudes from 3 to 11 km. The technique has also been used to measure carbon dioxide and monoxide, water vapor, and other trace gases in the near and mid-infrared spectral regions on the ground.

  17. Methane emission by adult ostriches (Struthio camelus).

    PubMed

    Frei, Samuel; Dittmann, Marie T; Reutlinger, Christoph; Ortmann, Sylvia; Hatt, Jean-Michel; Kreuzer, Michael; Clauss, Marcus

    2015-02-01

    Ostriches (Struthio camelus) are herbivorous birds with a digestive physiology that shares several similarities with that of herbivorous mammals. Previous reports, however, claimed a very low methane emission from ostriches, which would be clearly different from mammals. If this could be confirmed, ostrich meat would represent a very attractive alternative to ruminant-and generally mammalian-meat by representing a particularly low-emission agricultural form of production. We individually measured, by chamber respirometry, the amount of oxygen consumed as well as carbon dioxide and methane emitted from six adult ostriches (body mass 108.3±8.3 kg) during a 24-hour period when fed a pelleted lucerne diet. While oxygen consumption was in the range of values previously reported for ostriches, supporting the validity of our experimental setup, methane production was, at 17.5±3.2 L d(-1), much higher than previously reported for this species, and was of the magnitude expected for similar-sized, nonruminant mammalian herbivores. These results suggest that methane emission is similar between ostriches and nonruminant mammalian herbivores and that the environmental burden of these animals is comparable. The findings furthermore indicate that it appears justified to use currently available scaling equations for methane production of nonruminant mammals in paleo-reconstructions of methane production of herbivorous dinosaurs. PMID:25446146

  18. Responses of methane effluxes and soil methane concentrations to compaction.

    NASA Astrophysics Data System (ADS)

    Plain, C.; Delogu, E.; Longdoz, B.; Epron, D.; Ranger, J.

    2015-12-01

    Forest soils host methanotrophic bacterial communities that make them a major methane sink worldwide. Soil compaction resulting from mechanization of forest operations is first affecting soil macroporosity, and thus gas and water transfer within the soil, leading to a reduced oxygenation of the soil. This reduction of soil aeration is expected to reduce the methanotrophic activity leading thus to less CH4 oxidation and more CH4 production, affecting the overall soil CH4budget. Compaction was applied in 2007 and had created linear ruts. We measured continuously since September 2014, in three different situations (compacted-mound, compacted hollow and control), soil CO2 and CH4 effluxes using closed chamber coupled to a cavity ring down spectrometer in an young oak plantation. Since December 2015, in addition to these measurements, we have implanted hydrophobic tubes to measure vertical soil profiles of CH4, O2 and CO2 concentrations in the 3 situations. The soil acts as CH4 sink, with no significant difference in net CH4uptake between control and both hollow and mound in the compacted treatment. However, the uptake of CH4 was significantly lower for the hollows than for the mounds resulting from both a lower diffusion of CH4 within soil and a higher production of CH4 in deeper layer when the soil is water saturated.

  19. Inhibitory effects of sulfur compounds on methane oxidation by a methane-oxidizing consortium.

    PubMed

    Lee, Eun-Hee; Moon, Kyung-Eun; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

    2015-12-01

    Kinetic and enzymatic inhibition experiments were performed to investigate the effects of methanethiol (MT) and hydrogen sulfide (H2S) on methane oxidation by a methane-oxidizing consortium. In the coexistence of MT and H2S, the oxidation of methane was delayed until MT and H2S were completely degraded. MT and H2S could be degraded, both with and without methane. The kinetic analysis revealed that the methane-oxidizing consortium showed a maximum methane oxidation rate (Vmax) of 3.7 mmol g-dry cell weight (DCW)(-1) h(-1) and a saturation constant (Km) of 184.1 μM. MT and H2S show competitive inhibition on methane oxidation, with inhibition values (Ki) of 1504.8 and 359.8 μM, respectively. MT was primary removed by particulate methane monooxygenases (pMMO) of the consortium, while H2S was degraded by the other microorganisms or enzymes in the consortium. DNA and mRNA transcript levels of the pmoA gene expressions were decreased to ∼10(6) and 10(3)pmoA gene copy number g-DCW(-1) after MT and H2S degradation, respectively; however, both the amount of the DNA and mRNA transcript recovered their initial levels of ∼10(7) and 10(5)pmoA gene copy number g-DCW(-1) after methane oxidation, respectively. The gene expression results indicate that the pmoA gene could be rapidly reproducible after methane oxidation. This study provides comprehensive information of kinetic interactions between methane and sulfur compounds. PMID:26143035

  20. Isotopic composition of methane released from wetlands: Implications for the increase in atmospheric methane

    SciTech Connect

    Quay, P.D.; King, S.L.; Lansdown, J.M.; Wilbur, D.O. )

    1988-12-01

    Measurements of the delta-C{sup 13} of methane released from tropical, temperate, and arctic wetland sites are reported. The mean delta C{sup 13} values (relative to PDB carbonate standard) for peat bogs and Alaskan tundra are {minus}53 + or{minus}8, {minus}66 + or{minus}5 and {minus}64 + or{minus}5{per thousand}, respectively. These measurements combined with methane flux estimates yield a flux-weighted global average delta-C{sup 13} value of {minus}59 + or{minus}6{per thousand} for methane released from wetlands, a major natural methane source. The agreement between the measured delta-C{sup 13} for methane emitted from wetlands and the calculated steady state value of approximately {minus}6{per thousand} for the delta-C{sup 13} of preindustrial methane sources suggests that methane was predominantly produced biogenically in the preindustrial era. The industrial era time rate of change of the delta-C{sup 13} of the global methane flux is calculated from estimates of the growth rate of the major anthropogenically derived methane sources and the C{sup 13} composition of these sources, and compared to the measured change in the delta-C{sup 13} of methane during the last 300 years. Based on these results, it is estimated that 13 + or{minus}8% of the current global methane flux is derived abiogenically from natural gas and biomass burning, whereas the remainder is derived biogenically primarily from wetlands, rice paddies, and livestock. 40 refs., 5 figs., 2 tabs.

  1. Transcriptomic evidence for net methane oxidation and net methane production in putative ANaerobic MEthanotrophic (ANME) archaea

    NASA Astrophysics Data System (ADS)

    Lloyd, K. G.; Alperin, M. J.; Teske, A.

    2010-12-01

    Anaerobic methane oxidation regulates methane emissions in marine sediments and is thought to be mediated by uncultured methanogen-like archaea collectively labeled ANME (for ANaerobic MEthanotrophs). ANME archaea are often assumed to be obligate methanotrophs that are incapable of net methanogenesis, and are therefore used as proxies for anaerobic methane oxidation in many environments in spite of uncertainty regarding their metabolic capabilities. We tested this assumption by detecting and quantifying methanogenic gene transcription of ANME archaea across clearly differentiated zones of methane oxidation vs. methane production in sediments from the White Oak River estuary, NC. ANME-1 archaea (a group of putative obligate methanotrophs) consistently transcribe 16S rRNA and mRNA of methyl coenzyme M reductase (mcrA) the key gene for methanogenesis, up to 45 cm into methanogenic sediments. CARD-FISH shows that ANME-1 archaea exist as single rod-shaped cells or pairs of cells, and in very low numbers. Integrating normalized depth-distributions of 16S rDNA and rRNA (measured with qPCR and RT-qPCR, respectively) shows that 26-77 % of the rDNA proxy for ANME-1 cell numbers, and 18-74 % of the rRNA proxy for ANME-1 activity occurs within methane-producing sediments. mRNA transcripts of dissimilatory sulfite reductase (dsrAB) from sulfate reducing bacteria, the putative syntrophic partners of sulfate-dependent methane oxidation, were amplified consistently from methane-oxidizing sediments, and inconsistently from methane-producing sediments. These results change the perspective from ANME-1 archaea as obligate methane oxidizers to methanogens that are also capable of methane oxidation.

  2. Inhibitory effects of sulfur compounds on methane oxidation by a methane-oxidizing consortium.

    PubMed

    Lee, Eun-Hee; Moon, Kyung-Eun; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

    2015-12-01

    Kinetic and enzymatic inhibition experiments were performed to investigate the effects of methanethiol (MT) and hydrogen sulfide (H2S) on methane oxidation by a methane-oxidizing consortium. In the coexistence of MT and H2S, the oxidation of methane was delayed until MT and H2S were completely degraded. MT and H2S could be degraded, both with and without methane. The kinetic analysis revealed that the methane-oxidizing consortium showed a maximum methane oxidation rate (Vmax) of 3.7 mmol g-dry cell weight (DCW)(-1) h(-1) and a saturation constant (Km) of 184.1 μM. MT and H2S show competitive inhibition on methane oxidation, with inhibition values (Ki) of 1504.8 and 359.8 μM, respectively. MT was primary removed by particulate methane monooxygenases (pMMO) of the consortium, while H2S was degraded by the other microorganisms or enzymes in the consortium. DNA and mRNA transcript levels of the pmoA gene expressions were decreased to ∼10(6) and 10(3)pmoA gene copy number g-DCW(-1) after MT and H2S degradation, respectively; however, both the amount of the DNA and mRNA transcript recovered their initial levels of ∼10(7) and 10(5)pmoA gene copy number g-DCW(-1) after methane oxidation, respectively. The gene expression results indicate that the pmoA gene could be rapidly reproducible after methane oxidation. This study provides comprehensive information of kinetic interactions between methane and sulfur compounds.

  3. Methane Fluxes from Subtropical Wetlands

    NASA Astrophysics Data System (ADS)

    DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.

    2013-12-01

    It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify

  4. [Effect of temperature on methane production and oxidation in soils].

    PubMed

    Ding, Weixin; Cai, Zucong

    2003-04-01

    The influence of temperature and its mechanism on methane production and oxidation in soils were reviewed in this paper. Temperature can alter the soil ability to produce methane through changing types of dominant methanogens in archaeal community. Dominant methanogen is Methanosarcinaceae at higher temperature which can utilize both H2/CO2 and acetate as the precursor to produce methane, while Methanosaetaceae at lower temperature which only use acetate as the precursor and produce far less methane than do Methanosarcinaceae. Increasing soil temperature apparently raises soil ability to produce methane, which is called temperature effectiveness and expressed as Q10 with a range from 1.5 to 28 and an average of 4.1. There is an obviously positive correlation between temperature effectiveness (Q10) on methane production and substrate content. As compared to methane production, effect of temperature on methane oxidation is lower, which may be related to the strong affinity of methanotrophs for methane.

  5. Coal and coalbed-methane resources in the Appalachian and Black Warrior basins: maps showing the distribution of coal fields, coal beds, and coalbed-methane fields: Chapter D.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Trippi, Michael H.; Ruppert, Leslie F.; Milici, Robert C.; Kinney, Scott A.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The study area for most reports in this volume is the Appalachian basin. The term “Appalachian basin study area” (shortened from “Appalachian basin geologic framework study area”) includes all of the Appalachian Basin Province (Province 67) and part of the neighboring Black Warrior Basin Province (Province 65) of Dolton and others (1995). The boundaries for these two provinces and the study area are shown on figure 1.

  6. In situ methane enrichment in anaerobic digestion.

    PubMed

    Hayes, T D; Isaacson, H R; Pfeffer, J T; Liu, Y M

    1990-01-01

    A major cost consideration in the use of anaerobic digestion to convert biomass and waste to utility-grade gas is the expense of separating CO(2) from the product gas. Anaerobic digestion has a number of inherent properties that can be exploited to increase the methane content of the gas directly produced by the digester, the most important of which is the high solubility of CO(2)(40-60 times that of methane) in water under digestion conditions. The methane enrichment concept examined in this study involved the recirculation of a liquid stream from the digester through a CO(2) desorption process and the return of the liquid stream back to the digester for absorption of additional CO(2) produced by the conversion of organic materials. A steady-state equilibrium model predicted that a digester gas methane content exceeding 94% could be achieved with this scheme using modest recirculation rates provided a desorption process could be designed to achieve a 60+% CO(2) removal efficiency in the degassing of the liquid recycle stream. Using fixed-film laboratory digesters operated on synthetic feedstocks, the technique of methane enrichment was tested under pressurized and unpressurized conditions. A 93 + 2% methane gas stream was produced from a volatile-acid-fed bench-scale digester simulating the methanogenic stage of two-phase digestion under conditions of (1) a pH swing achieved without caustic addition that allowed digestion at pH 7. 5 and air stripping at pH 6. 5-7. 0, (2) digester pressurization to 30 psig, and (3) a recycle rate of 0. 33 L/L reactor/day. Significant but lower levels of methane enrichment were achieved with the single-stage digester at the low experimental recycle rate. However, the narrow range among all experiments of CO(2) desorption efficiencies achieved in air stripping the recycle stream (35-60% CO(2) removal) suggests that comparable methane enrichment-may be achieved with unpressurized single-stage digestion using greater recycle rates. A

  7. Detection of Abiotic Methane in Terrestrial Continental Hydrothermal Systems: Implications for Methane on Mars

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Niles, Paul B.; Gibson, Everett K., Jr.; Romanek, Christopher S.; Zhang, Chuanlun L.; Bissada, Kadry K.

    2008-01-01

    The recent detection of methane in the Martian atmosphere and the possibility that its origin could be attributed to biological activity, have highlighted the importance of understanding the mechanisms of methane formation and its usefulness as a biomarker. Much debate has centered on the source of the methane in hydrothermal fluids, whether it is formed biologically by microorganisms, diagenetically through the decomposition of sedimentary organic matter, or inorganically via reduction of CO2 at high temperatures. Ongoing research has now shown that much of the methane present in sea-floor hydrothermal systems is probably formed through inorganic CO2 reduction processes at very high temperatures (greater than 400 C). Experimental results have indicated that methane might form inorganically at temperatures lower still, however these results remain controversial. Currently, methane in continental hydrothermal systems is thought to be formed mainly through the breakdown of sedimentary organic matter and carbon isotope equilibrium between CO2 and CH4 is thought to be rarely present if at all. Based on isotopic measurements of CO2 and CH4 in two continental hydrothermal systems, we suggest that carbon isotope equilibration exists at temperatures as low as 155 C. This would indicate that methane is forming through abiotic CO2 reduction at lower temperatures than previously thought and could bolster arguments for an abiotic origin of the methane detected in the martian atmosphere.

  8. Anaerobic methane oxidation in low-organic content methane seep sediments

    USGS Publications Warehouse

    Pohlman, John W.; Riedel, Michael; Bauer, James E.; Canuel, Elizabeth A.; Paull, Charles K.; Lapham, Laura; Grabowski, Kenneth S.; Coffin, Richard B.; Spence, George D.

    2013-01-01

    Sulfate-dependent anaerobic oxidation of methane (AOM) is the key sedimentary microbial process limiting methane emissions from marine sediments and methane seeps. In this study, we investigate how the presence of low-organic content sediment influences the capacity and efficiency of AOM at Bullseye vent, a gas hydrate-bearing cold seep offshore of Vancouver Island, Canada. The upper 8 m of sediment contains 14C. A fossil origin for the DIC precludes remineralization of non-fossil OM present within the sulfate zone as a significant contributor to pore water DIC, suggesting that nearly all sulfate is available for anaerobic oxidation of fossil seep methane. Methane flux from the SMT to the sediment water interface in a diffusion-dominated flux region of Bullseye vent was, on average, 96% less than at an OM-rich seep in the Gulf of Mexico with a similar methane flux regime. Evidence for enhanced methane oxidation capacity within OM-poor sediments has implications for assessing how climate-sensitive reservoirs of sedimentary methane (e.g., gas hydrate) will respond to ocean warming, particularly along glacially-influenced mid and high latitude continental margins.

  9. Methane, microbes and models: fundamental understanding of the soil methane cycle for future predictions.

    PubMed

    Nazaries, Loïc; Murrell, J Colin; Millard, Pete; Baggs, Liz; Singh, Brajesh K

    2013-09-01

    Methane is an important greenhouse gas and microbes in the environment play major roles in both global methane emissions and terrestrial sinks. However, a full mechanistic understanding of the response of the methane cycle to global change is lacking. Recent studies suggest that a number of biological and environmental processes can influence the net flux of methane from soils to the atmosphere but the magnitude and direction of their impact are still debated. Here, we synthesize recent knowledge on soil microbial and biogeochemical process and the impacts of climate change factors on the soil methane cycle. We focus on (i) identification of the source and magnitude of methane flux and the global factors that may change the flux rate and magnitude in the future, (ii) the microbial communities responsible for methane production and terrestrial sinks, and (iii) how they will respond to future climatic scenarios and the consequences for feedback responses at a global scale. We also identify the research gaps in each of the topics identified above, provide evidence which can be used to demonstrate microbial regulation of methane cycle and suggest that incorporation of microbial data from emerging -omic technologies could be harnessed to increase the predictive power of simulation models. PMID:23718889

  10. Atmospheric methane removal by methane-oxidizing bacteria immobilized on porous building materials.

    PubMed

    Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Hoefman, Sven; De Vos, Paul; Boeckx, Pascal; Boon, Nico

    2014-04-01

    Biological treatment using methane-oxidizing bacteria (MOB) immobilized on six porous carrier materials have been used to mitigate methane emission. Experiments were performed with different MOB inoculated in building materials at high (~20 % (v/v)) and low (~100 ppmv) methane mixing ratios. Methylocystis parvus in autoclaved aerated concrete (AAC) exhibited the highest methane removal rate at high (28.5 ± 3.8 μg CH₄ g⁻¹ building material h⁻¹) and low (1.7 ± 0.4 μg CH₄ g⁻¹ building material h⁻¹) methane mixing ratio. Due to the higher volume of pores with diameter >5 μm compared to other materials tested, AAC was able to adsorb more bacteria which might explain for the higher methane removal observed. The total methane and carbon dioxide-carbon in the headspace was decreased for 65.2 ± 10.9 % when M. parvus in Ytong was incubated for 100 h. This study showed that immobilized MOB on building materials could be used to remove methane from the air and also act as carbon sink.

  11. High-pressure phase diagrams of methane + squalane and methane + hexatriacontane mixtures

    SciTech Connect

    Marteau, P.; Tobaly, P.; Ruffier-Meray, V.; Hemptinne, J.C. de

    1998-05-01

    Thermodynamic properties of crude oils and natural gases are important for optimizing operating conditions. Equilibrium data on the methane + hexatriacontane mixture at (373, 398, 423, and 453) K and on the methane + squalane (2,6,10,15,19,23-hexamethyltetracosane) mixture at (323, 370, 420) K are reported. The apparatus and the near-infrared absorption method have been previously described.

  12. Turbulent Methane-Air Combustion

    NASA Technical Reports Server (NTRS)

    Yaboah, Yaw D.; Njokwe, Anny; James, LaShanda

    1996-01-01

    This study is aimed at enhancing the understanding of turbulent premixed methane-air combustion. Such understanding is essential since: (1) many industries are now pursuing lighter hydrocarbon alternative fuels and the use of premixed flames to reduce pollutant emissions, and (2) the characteristic dimensions and flow rates of most industrial combustors are often large for flows to be turbulent. The specific objectives of the study are: (1) to establish the effects of process variables (e.g., flow rate, fuel/air ratio, chlorinated hydro-carbons, and pressure) on the emissions and flow structure (velocity distribution, streamlines, vorticity and flame shape), and (2) to develop a mechanistic model to explain the observed trends. This includes the acquisition of Dantec FlowMap Particle Image Velocimeter. The design and fabrication of the premixed burner has also been completed. The study is now at the stage of testing of equipment and analytical instruments. The presentation will give details on the tasks completed and on the current and future plans. The project is progressing well and all activities are on schedule. The outlook for the success of the project is bright.

  13. Gaia's breath - Global methane exhalations

    USGS Publications Warehouse

    Kvenvolden, K.A.; Rogers, B.W.

    2005-01-01

    Methane (CH4) is the most abundant organic compound in the Earth's atmosphere, where it acts as a greenhouse gas and thus has implications for global climate change. The current atmospheric CH4 budget, however, does not take into account geologically-sourced CH4 seepage. Geological sources of CH4 include natural macro- and micro-seeps, mud volcanoes, and other miscellaneous sources such as gas hydrates, magmatic volcanoes, geothermal regions, and mid-ocean ridges. Macro-seeps contribute ???25 Tg (teragrams) CH4/yr to the atmosphere, whereas, micro-seepage contributes perhaps 7 Tg CH4/yr. Mud volcanoes emit ???5 Tg CH4/yr, and miscellaneous sources emit ???8 Tg CH4/yr to the atmosphere. Thus, the total contribution to the atmosphere from geological sources is estimated to be 45 Tg CH4/yr, which is significant to the atmospheric organic carbon cycle and should be included in any global inventory of atmospheric CH4. We argue that the atmospheric CH4 global inventory of the Interplanetary Panel on Climate Change must be adjusted in order to incorporate geologically-sourced CH4 from naturally occurring seepage.

  14. Investigations of Methane Production in Hypersaline Environments

    NASA Technical Reports Server (NTRS)

    Bebout, Brad M.

    2015-01-01

    The recent reports of methane in the atmosphere of Mars, as well as the findings of hypersaline paleo-environments on that planet, have underscored the need to evaluate the importance of biological (as opposed to geological) trace gas production and consumption. Methane in the atmosphere of Mars may be an indication of life but might also be a consequence of geologic activity and/or the thermal alteration of ancient organic matter. Hypersaline environments have now been reported to be extremely likely in several locations in our solar system, including: Mars, Europa, and Enceladus. Modern hypersaline microbial mat communities, (thought to be analogous to those present on the early Earth at a period of time when Mars was experiencing very similar environmental conditions), have been shown to produce methane. However, very little is known about the physical and/or biological controls imposed upon the rates at which methane, and other important trace gases, are produced and consumed in these environments. We describe here the results of our investigations of methane production in hypersaline environments, including field sites in Chile, Baja California Mexico, California, USA and the United Arab Emirates. We have measured high concentrations of methane in bubbles of gas produced both in the sediments underlying microbial mats, as well as in areas not colonized by microbial mats in the Guerrero Negro hypersaline ecosystem, Baja California Mexico, in Chile, and in salt ponds on the San Francisco Bay. The carbon isotopic (d13C) composition of the methane in the bubbles exhibited an extremely wide range of values, (ca. -75 per mille ca. -25 per mille). The hydrogen isotopic composition of the methane (d2H) ranged from -60 to -30per mille and -450 to -350per mille. These isotopic values are outside of the range of values normally considered to be biogenic, however incubations of the sediments in contact with these gas bubbles reveals that the methane is indeed being

  15. Influence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests.

    PubMed

    Valero, David; Montes, Jesús A; Rico, José Luis; Rico, Carlos

    2016-02-01

    The biochemical methane potential test is the most commonly applied method to determine methane production from organic wastes. One of the parameters measured is the volume of biogas produced which can be determined manometrically by keeping the volume constant and measuring increases in pressure. In the present study, the effect of pressure accumulation in the headspace of the reactors has been studied. Triplicate batch trials employing cocoa shell, waste coffee grounds and dairy manure as substrates have been performed under two headspace pressure conditions. The results obtained in the study showed that headspace overpressures higher than 600mbar affected methane production for waste coffee grounds. On the contrary, headspace overpressures within a range of 600-1000mbar did not affect methane production for cocoa shell and dairy manure. With the analyses performed in the present work it has not been possible to determine the reasons for the lower methane yield value obtained for the waste coffee grounds under high headspace pressures.

  16. Forest cockchafer larvae as methane production hotspots in soils and their importance for net soil methane fluxes

    NASA Astrophysics Data System (ADS)

    Görres, Carolyn-Monika; Kammann, Claudia; Murphy, Paul; Müller, Christoph

    2016-04-01

    Certain groups of soil invertebrates, namely scarab beetles and millipedes, are capable of emitting considerable amounts of methane due to methanogens inhabiting their gut system. It was already pointed out in the early 1990's, that these groups of invertebrates may represent a globally important source of methane. However, apart from termites, the importance of invertebrates for the soil methane budget is still unknown. Here, we present preliminary results of a laboratory soil incubation experiment elucidating the influence of forest cockchafer larvae (Melolontha hippocastani FABRICIUS) on soil methane cycling. In January/February 2016, two soils from two different management systems - one from a pine forest (extensive use) and one from a vegetable field (intensive use) - were incubated for 56 days either with or without beetle larvae. Net soil methane fluxes and larvae methane emissions together with their stable carbon isotope signatures were quantified at regular intervals to estimate gross methane production and gross methane oxidation in the soils. The results of this experiment will contribute to testing the hypothesis of whether methane production hotspots can significantly enhance the methane oxidation capacity of soils. Forest cockchafer larvae are only found in well-aerated sandy soils where one would usually not suspect relevant gross methane production. Thus, besides quantifying their contribution to net soil methane fluxes, they are also ideal organisms to study the effect of methane production hotspots on overall soil methane cycling. Funding support: Reintegration grant of the German Academic Exchange Service (DAAD) (#57185798).

  17. Extracting value from coal mine methane

    SciTech Connect

    Liebert, B.

    2009-06-15

    Emerging US policy to regulate greenhouse gas (GHG) emissions through a cap-and-trade program presents mine managers with a new opportunity to explore and develop methane utilization or abatement projects that generate value from the anodization of carbon offset credits. In addition, the rising focus on US energy security and domestic energy supply is promoting mine managers and engineers to give further consideration to the importance of their methane gas by-products. The market through which coal mine methane offset projects can be developed and carbon offset credits monetized is quickly maturing. While many methane utilization projects have previously been uneconomical, the carbon offset credit market provides a new set of financing tools for mine engineers to capitalize these projects today. Currently , there are two certification programs that have approved project protocols for CMM projects. The Voluntary Carbon Standard (VCS) offers a methodology approved under the Clean Development Mechanism, the international compliance based offset market under the Kyoto Protocol. The VCS protocol is applicable to projects that combust ventilation air methane (VAM) and methane extracted from pre-and post-mine drainage systems. The Chicago Climate Exchange (CCX), which operates a voluntary yet binding cap-and-trade market, also has an approved protocol for CMM projects. CCX's protocol can be applied to projects combusting VAM, and methane extracted from pre-and-post-mine drainage systems, as well as abandoned mines. The article describes two case studies - Developing a gob gas utilization project financed by carbon offset credits and First VAM oxidation system to be commissioned at an operating mine in the US. 1 tab., 4 photos.

  18. Geologic emissions of methane to the atmosphere.

    PubMed

    Etiope, Giuseppe; Klusman, Ronald W

    2002-12-01

    The atmospheric methane budget is commonly defined assuming that major sources derive from the biosphere (wetlands, rice paddies, animals, termites) and that fossil, radiocarbon-free CH4 emission is due to and mediated by anthropogenic activity (natural gas production and distribution, and coal mining). However, the amount of radiocarbon-free CH4 in the atmosphere, estimated at approximately 20% of atmospheric CH4, is higher than the estimates from statistical data of CH4 emission from fossil fuel related anthropogenic sources. This work documents that significant amounts of "old" methane, produced within the Earth crust, can be released naturally into the atmosphere through gas permeable faults and fractured rocks. Major geologic emissions of methane are related to hydrocarbon production in sedimentary basins (biogenic and thermogenic methane) and, subordinately, to inorganic reactions (Fischer-Tropsch type) in geothermal systems. Geologic CH4 emissions include diffuse fluxes over wide areas, or microseepage, on the order of 10(0)-10(2) mg m(-2) day(-1), and localised flows and gas vents, on the order of 10(2) t y(-1), both on land and on the seafloor. Mud volcanoes producing flows of up to 10(3) t y(-1) represent the largest visible expression of geologic methane emission. Several studies have indicated that methanotrophic consumption in soil may be insufficient to consume all leaking geologic CH4 and positive fluxes into the atmosphere can take place in dry or seasonally cold environments. Unsaturated soils have generally been considered a major sink for atmospheric methane, and never a continuous, intermittent, or localised source to the atmosphere. Although geologic CH4 sources need to be quantified more accurately, a preliminary global estimate indicates that there are likely more than enough sources to provide the amount of methane required to account for the suspected missing source of fossil CH4.

  19. Methane in permafrost - Preliminary results from coring at Fairbanks, Alaska

    USGS Publications Warehouse

    Kvenvolden, K.A.; Lorenson, T.D.

    1993-01-01

    Permafrost has been suggested as a high-latitude source of methane (a greenhouse gas) during global warming. To begin to assess the magnitude of this source, we have examined the methane content of permafrost in samples from shallow cores (maximum depth, 9.5m) at three sites in Fairbanks, Alaska, where discontinuous permafrost is common. These cores sampled frozen loess, peat, and water (ice) below the active layer. Methane contents of permafrost range from <0.001 to 22.2mg/kg of sample. The highest methane content of 22.2mg/kg was found in association with peat at one site. Silty loess had high methane contents at each site of 6.56, 4.24, and 0.152mg/kg, respectively. Carbon isotopic compositions of the methane (??13C) ranged from -70.8 to -103.9 ???, and hydrogen isotopic compositions of the methane (??D) from -213 to -313 ???, indicating that the methane is microbial in origin. The methane concentrations were used in a one dimensional heat conduction model to predict the amount of methane that will be released from permafrost worldwide over the next 100 years, given two climate change scenarios. Our results indicate that at least 30 years will elapse before melting permafrost releases important amounts of methane; a maximum methane release rate will be about 25 to 30 Tg/yr, assuming that methane is generally distributed in shallow permafrost as observed in our samples.

  20. Estimating methane fluxes at a landscape scale

    NASA Astrophysics Data System (ADS)

    Stockdale, James; MacBean, Natasha

    2010-05-01

    Terrestrial methane fluxes are an important component of peatland carbon budgets. Using a well-studied peatland site in Wales as a case study, we present a variety of approaches to quantifying annual methane fluxes at a landscape scale, with a focus on the comparison between a simple stratification method, an empirical regression-based method and a process-based method. The simplest approach relies on in situ methane flux measurements which, due to the indirect effects on methane flux from the vascular transport mechanism and co-variation with hydrological conditions, were stratified by vegetation type. Aside from this initial classification, an annual landscape flux was produced through a linear scaling model without attempting to consider any physical, chemical or biological processes known to control methane fluxes. The regress