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Sample records for characterizing co2 seepage

  1. The role of optimality in characterizing CO2 seepage from geological carbon sequestration sites

    SciTech Connect

    Cortis, Andrea; Oldenburg, Curtis M.; Benson, Sally M.

    2008-09-15

    Storage of large amounts of carbon dioxide (CO{sub 2}) in deep geological formations for greenhouse gas mitigation is gaining momentum and moving from its conceptual and testing stages towards widespread application. In this work we explore various optimization strategies for characterizing surface leakage (seepage) using near-surface measurement approaches such as accumulation chambers and eddy covariance towers. Seepage characterization objectives and limitations need to be defined carefully from the outset especially in light of large natural background variations that can mask seepage. The cost and sensitivity of seepage detection are related to four critical length scales pertaining to the size of the: (1) region that needs to be monitored; (2) footprint of the measurement approach, and (3) main seepage zone; and (4) region in which concentrations or fluxes are influenced by seepage. Seepage characterization objectives may include one or all of the tasks of detecting, locating, and quantifying seepage. Each of these tasks has its own optimal strategy. Detecting and locating seepage in a region in which there is no expected or preferred location for seepage nor existing evidence for seepage requires monitoring on a fixed grid, e.g., using eddy covariance towers. The fixed-grid approaches needed to detect seepage are expected to require large numbers of eddy covariance towers for large-scale geologic CO{sub 2} storage. Once seepage has been detected and roughly located, seepage zones and features can be optimally pinpointed through a dynamic search strategy, e.g., employing accumulation chambers and/or soil-gas sampling. Quantification of seepage rates can be done through measurements on a localized fixed grid once the seepage is pinpointed. Background measurements are essential for seepage detection in natural ecosystems. Artificial neural networks are considered as regression models useful for distinguishing natural system behavior from anomalous behavior

  2. Modeling of Near-Surface Leakage and Seepage of CO2 for Risk Characterization

    SciTech Connect

    Oldenburg, Curtis M.; Unger, Andre A.J.

    2004-02-18

    The injection of carbon dioxide (CO2) into deep geologic carbon sequestration sites entails risk that CO2 will leak away from the primary storage formation and migrate upwards to the unsaturated zone from which it can seep out of the ground. We have developed a coupled modeling framework called T2CA for simulating CO2 leakage and seepage in the subsurface and in the atmospheric surface layer. The results of model simulations can be used to calculate the two key health, safety, and environmental (HSE) risk drivers, namely CO2 seepage flux and nearsurface CO2 concentrations. Sensitivity studies for a subsurface system with a thick unsaturated zone show limited leakage attenuation resulting in correspondingly large CO2 concentrations in the shallow subsurface. Large CO2 concentrations in the shallow subsurface present a risk to plant and tree roots, and to humans and other animals in subsurface structures such as basements or utility vaults. Whereas CO2 concentrations in the subsurface can be high, surfacelayer winds reduce CO2 concentrations to low levels for the fluxes investigated. We recommend more verification and case studies be carried out with T2CA, along with the development of extensions to handle additional scenarios such as calm conditions, topographic effects, and catastrophic surface-layer discharge events.

  3. Characterizing CO2 storage reservoir for above-zone monitoring

    NASA Astrophysics Data System (ADS)

    Zahid, K. M.; Hovorka, S. D.

    2011-12-01

    CO2 enhanced oil recovery (EOR) provides an excellent opportunity for commercial sequestration of anthropogenic CO2. Fluvial, strand plain, and deltaic sandstones of Oligocene and Miocene formations that extend across the Gulf Coast Basin were prolific oil producers for many decades and are also considered to be effective reservoirs for large scale carbon storage. A deep-seated salt dome, faulted anticlinal structure from Gulf coastal region is currently under investigation to develop a monitoring, verification, and accounting (MVA) plan as coordinated with commercial surveillance of an EOR site for injecting large volume (>1 Million ton/year) of CO2. Geophysical logs have been used to characterize the injection zone reservoir and overburden. One novel MVA element in design is above-zone pressure and geochemical monitoring for out-of-zone migration. Initial characterization with wireline logs demonstrates the extent and areal continuity of reservoir sands and geometries of faults that cut the reservoir. To develop the monitoring plan, we focus characterization on several elements: (1) input data for quick-look dynamic model of the extent of CO2 plume and amount and extent of accompanying pressure elevation, (2) characterization of the zones above the top-reservoir seal for above-zone pressure monitoring, and (3) intersection of faults with well-bores in intervals above the top-reservoir seal for thermal monitoring. Other uncertainties addressed during characterization are the upper extent of faults and juxtaposition of layers to assess the potential for cross-fault fluid migration. Such detail characterization will allow realistic assessment of the sensitivity of monitoring techniques such as temperature logging for tracking up-fault fluid migration and pressure change for out-of zone fluid migration. Successful use of such geophysical techniques for MVA based on uniting elements of existing regulatory monitoring expectations with commercial best practices will be

  4. Characterization of CO2 leakage into the freshwater body

    NASA Astrophysics Data System (ADS)

    Singh, Ashok; Delfs, Jens-Olaf; Shao, Habing; Kolditz, Olaf

    2013-04-01

    Current research into Carbon dioxide Capture and Storage (CCS) is dominated by improving the CO2 storage capacity. However, potential leakage of CO2 can cause environmental problems, particularly if freshwater resources are nearby. In this regards, it is important to understand the chemistry of CO2 and the water system. CO2 leakage across the fluid interface (CO2 and water) is controlled by the difference in the partial pressure of CO2 in the storage and in the freshwater body. Once the CO2 is in solution, it equilibrates with the bicarbonate and carbonate ions. According to Millero (1994)such a system can be characterized by two parameters out of the four: total alkalinity (TA), total carbonate (TCO2), fugacity of CO2(fCO2) and pH. In the present modeling study, we are interested in the (i) CO2 leakage into a freshwater body (while injecting CO2 for storage) through an inclined fracture and (ii) characterization of the system by measuring fugacity of CO2 and pH. According to work presented by Singh et al. (2012), about 31% of injected CO2 leaks into the freshwater body. Solubility of CO2 in water follows Henry's law, while the Henry constant, K0 is calculated by an empirical relation developed by Murray and Riley (1971), which is a function of salinity and temperature. According to our results, pH and fugacity both appear to be a linear function of temperature. To simulate the discussed problem, a corresponding numerical module has been developed for multi-component fluid flow coupled with heat and mass transport processes. Governing equations and Volume Translated Peng-Robinson equations of state are implemented within the object-oriented finite element code OpenGeoSys (Kolditz et al., 2012; www.opengeosys.org). Primary variables are pressure, temperature and salinity which are obtained by solving the governing equations in a monolithic way The governing equations are discretized spatially within the context of a Galerkin approach, whereas the temporal

  5. Characterization of CO2 reservoir rock in Switzerland

    NASA Astrophysics Data System (ADS)

    Fabbri, Stefano; Madonna, Claudio; Zappone, Alba

    2014-05-01

    Anthropogenic emissions of Carbon Dioxide (CO2) are one of the key drivers regarding global climate change (IPCC, 2007). Carbon Dioxide Capture and Storage (CCS) is one valuable technology to mitigate current climate change with an immediate impact. The IPCC special report on CCS predicted a potential capture range of 4.7 to 37.5 Gt of CO2 by 2050. Among several countries, Switzerland has started to investigate its potential for CO2 storage (Chevalier et al., 2010) and is currently performing research on the characterization of the most promising reservoir/seal rocks for CO2 sequestration. For Switzerland, the most feasible option is to store CO2 in saline aquifers, sealed by impermeable formations. One aquifer of regional scale in the Swiss Molasse Basin is a carbonate sequence consisting of reworked shallow marine limestones and accumulations of shell fragments. The upper part of the formation presents the most promising permeability values and storage properties. The storage potential has been estimated of 706 Mt of CO2, based on the specific ranking scheme proposed by Chevalier et al. 2010. In this study, key parameters such as porosity, permeability and acoustic velocities in compressional and shear mode have been measured in laboratory at pressures and temperatures simulating in situ conditions. Reservoir rock samples have been investigated. Permeability has been estimated before and after CO2 injection in supercritical state. The simulation of typical reservoir conditions allows us to go one step further towards a significant evaluation of the reservoir's true capacities for CO2 sequestration. It seems of major importance to notice that the permeability crucially depends on confining pressure, temperature and pore pressure conditions of the sample. Especially at in situ conditions with CO2 being at supercritical state, a substantial loss in permeability have to be taken into consideration when it comes to the calculation of potential injection rates. The

  6. International Symposium on Site Characterization for CO2Geological Storage

    SciTech Connect

    Tsang, Chin-Fu

    2006-02-23

    Several technological options have been proposed to stabilize atmospheric concentrations of CO{sub 2}. One proposed remedy is to separate and capture CO{sub 2} from fossil-fuel power plants and other stationary industrial sources and to inject the CO{sub 2} into deep subsurface formations for long-term storage and sequestration. Characterization of geologic formations for sequestration of large quantities of CO{sub 2} needs to be carefully considered to ensure that sites are suitable for long-term storage and that there will be no adverse impacts to human health or the environment. The Intergovernmental Panel on Climate Change (IPCC) Special Report on Carbon Dioxide Capture and Storage (Final Draft, October 2005) states that ''Site characterization, selection and performance prediction are crucial for successful geological storage. Before selecting a site, the geological setting must be characterized to determine if the overlying cap rock will provide an effective seal, if there is a sufficiently voluminous and permeable storage formation, and whether any abandoned or active wells will compromise the integrity of the seal. Moreover, the availability of good site characterization data is critical for the reliability of models''. This International Symposium on Site Characterization for CO{sub 2} Geological Storage (CO2SC) addresses the particular issue of site characterization and site selection related to the geologic storage of carbon dioxide. Presentations and discussions cover the various aspects associated with characterization and selection of potential CO{sub 2} storage sites, with emphasis on advances in process understanding, development of measurement methods, identification of key site features and parameters, site characterization strategies, and case studies.

  7. Characterization of seepage in the exploratory studies facility, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Oliver, T.A.; Whelan, J.F.

    2006-01-01

    Following a 5-month period of above-average precipitation during the winter of 2004-2005, water was observed seeping into the South Ramp section of the Exploratory Studies Facility of the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada. Samples of the seepage were collected and analyzed for major ions, trace metals, and delta deuterium and delta oxygen-18 values in an effort to characterize the water and assess the interaction of seepage with anthropogenic materials used in the construction of the proposed repository. As demonstrated by the changes in the chemistry of water dripping from a rock bolt, interaction of seepage with construction materials can alter solution chemistry and oxidation state.

  8. Characterization of an HF-Pumped CO2 Laser.

    DTIC Science & Technology

    1981-10-01

    the 101 and 100 energy levels and lasing action is achieved at 4.3 microns. The results of a theoretical analysis and an experimental study are used...14 3 Predicted HF Power Pulse Shape .................. 30 4 Optical Pumping Schemes ......................... 31 5 CO2 Energy Level Diaqram...32 6 12C1802 Energy Level Diagram .................... 34 7 HF and CO2 Line Broadeninq ....................... 36 8 CO Absorption

  9. Seepage Calibration Model and Seepage Testing Data

    SciTech Connect

    P. Dixon

    2004-02-17

    The purpose of this Model Report is to document the Seepage Calibration Model (SCM). The SCM is developed (1) to establish the conceptual basis for the Seepage Model for Performance Assessment (SMPA), and (2) to derive seepage-relevant, model-related parameters and their distributions for use in the SMPA and seepage abstraction in support of the Total System Performance Assessment for License Application (TSPA-LA). The SCM is intended to be used only within this Model Report for the estimation of seepage-relevant parameters through calibration of the model against seepage-rate data from liquid-release tests performed in several niches along the Exploratory Studies Facility (ESF) Main Drift and in the Cross Drift. The SCM does not predict seepage into waste emplacement drifts under thermal or ambient conditions. Seepage predictions for waste emplacement drifts under ambient conditions will be performed with the SMPA (see upcoming REV 02 of CRWMS M&O 2000 [153314]), which inherits the conceptual basis and model-related parameters from the SCM. Seepage during the thermal period is examined separately in the Thermal Hydrologic (TH) Seepage Model (see BSC 2003 [161530]). The scope of this work is (1) to evaluate seepage rates measured during liquid-release experiments performed in several niches in the Exploratory Studies Facility (ESF) and in the Cross Drift, which was excavated for enhanced characterization of the repository block (ECRB); (2) to evaluate air-permeability data measured in boreholes above the niches and the Cross Drift to obtain the permeability structure for the seepage model; (3) to use inverse modeling to calibrate the SCM and to estimate seepage-relevant, model-related parameters on the drift scale; (4) to estimate the epistemic uncertainty of the derived parameters, based on the goodness-of-fit to the observed data and the sensitivity of calculated seepage with respect to the parameters of interest; (5) to characterize the aleatory uncertainty of

  10. Seepage Calibration Model and Seepage Testing Data

    SciTech Connect

    S. Finsterle

    2004-09-02

    The purpose of this Model Report is to document the Seepage Calibration Model (SCM). The SCM was developed (1) to establish the conceptual basis for the Seepage Model for Performance Assessment (SMPA), and (2) to derive seepage-relevant, model-related parameters and their distributions for use in the SMPA and seepage abstraction in support of the Total System Performance Assessment for License Application (TSPA-LA). This Model Report has been revised in response to a comprehensive, regulatory-focused evaluation performed by the Regulatory Integration Team [''Technical Work Plan for: Regulatory Integration Evaluation of Analysis and Model Reports Supporting the TSPA-LA'' (BSC 2004 [DIRS 169653])]. The SCM is intended to be used only within this Model Report for the estimation of seepage-relevant parameters through calibration of the model against seepage-rate data from liquid-release tests performed in several niches along the Exploratory Studies Facility (ESF) Main Drift and in the Cross-Drift. The SCM does not predict seepage into waste emplacement drifts under thermal or ambient conditions. Seepage predictions for waste emplacement drifts under ambient conditions will be performed with the SMPA [''Seepage Model for PA Including Drift Collapse'' (BSC 2004 [DIRS 167652])], which inherits the conceptual basis and model-related parameters from the SCM. Seepage during the thermal period is examined separately in the Thermal Hydrologic (TH) Seepage Model [see ''Drift-Scale Coupled Processes (DST and TH Seepage) Models'' (BSC 2004 [DIRS 170338])]. The scope of this work is (1) to evaluate seepage rates measured during liquid-release experiments performed in several niches in the Exploratory Studies Facility (ESF) and in the Cross-Drift, which was excavated for enhanced characterization of the repository block (ECRB); (2) to evaluate air-permeability data measured in boreholes above the niches and the Cross-Drift to obtain the permeability structure for the seepage model

  11. Utilizing geophysical methods for asessment and characterization of canal seepage in El Paso's lower valley irrigation delivery systems

    NASA Astrophysics Data System (ADS)

    Cegon, Amanda Brooke

    El Paso County Water Improvement District No. 1 (EPCWID No.1) delivers the Rio Grande water for agricultural production and urban uses through numerous networked irrigation canals. Of the nearly 86 billion gallons of water released annually for irrigation uses in Texas, billions are lost due to evaporation and seepage in unlined canals with 56 million gallons of the billions are lost in Franklin Canal annually due to improper lining and sediment variation of the canals. To characterize seepage patterns and identify areas of high seepage, Electrical Resistivity, Ground Truthing via soil sample analysis were used along three, half-mile long sectioned canals during irrigation and non-irrigation seasons. The data lines acquired were processed in EARTHIMAGER 2D to create 2D vertical resistivity inversion profiles to locate potential areas of high seepage/high resistivity. The research results will help El Paso County Water Improvement District No. 1 to develop management strategies to conserve water and improve the delivery efficiency systems which leads to economic growth in the Rio Grande Basin.

  12. Hydrogeological characterization of shallow-depth zone for CO2 injection and leak test at a CO2 environmental monitoring site in Korea

    NASA Astrophysics Data System (ADS)

    Lee, S. S.; Kim, T. W.; Kim, H. H.; Ha, S. W.; Jeon, W. T.; Lee, K. K.

    2015-12-01

    The main goal of the this study is to evaluate the importance of heterogeneities in controlling the field-scale transport of CO2 are originated from the CO2 injected at saturated zone below the water table for monitoring and prediction of CO2 leakage from a reservoir. Hydrogeological and geophysical data are collected to characterize the site, prior to conducting CO2 injection experiment at the CO2 environmental monitoring site at Eumseong, Korea. The geophysical data were acquired from borehole electromagnetic flowmeter tests, while the hydraulic data were obtained from pumping tests, slug tests, and falling head permeability tests. Total of 13 wells to perform hydraulic and geophysical test are established along groundwater flow direction in regular sequence, revealed by the results of borehole electromagnetic flowmeter test. The results of geophysical tests indicated that hydraulic gradient is not identical with the topographic gradient. Groundwater flows toward the uphill direction in the study area. Then, the hydraulic tests were conducted to identify the hydraulic properties of the study site. According to the results of pumping and slug tests at the study site, the hydraulic conductivity values show ranges between 4.75 x 10-5 cm/day and 9.74 x 10-5 cm/day. In addition, a portable multi-level sampling and monitoring packer device which remains inflated condition for a long period developed and used to isolate designated depths to identify vertical distribution of hydrogeological characteristics. Hydrogeological information obtained from this study will be used to decide the injection test interval of CO2-infused water and gaseous CO2. Acknowledgement: Financial support was provided by "R&D Project on Environmental Mangement of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003).

  13. Preparation and characterization of Ni-based perovskite catalyst for steam CO2 reforming of methane.

    PubMed

    Yang, Eun-Hyeok; Kim, Sang Woo; Ahn, Byong Song; Moon, Dong Ju

    2013-06-01

    Steam CO2 reforming of methane was investigated over Ni-based perovskite catalyst to produce desired H2/CO ratio by adjusting the feed ratio of CH4, CO2 and H2O for floating GTL process application. La modified perovskites were prepared by the Pechini method and calcined in air and the Ni-based catalysts were prepared by dispersing Ni on the La modified perovskite by an incipient wetness impregnation. The catalysts before and after the reaction were characterized by N2 physisoprtion, CO chemisoprtion, XRD, TPR and SEM techniques. To control desired H2/CO ratio, simulation for SCR was carried out by Aspen plus, and product distribution for SCR was investigated in a fixed bed reactor system using feed ratio estimated by simulation. The Ni-based perovskite catalysts were found to give CH4 and CO2 conversions of up to 82% and 60% respectively to yield a H2/CO product ratio close to 2.

  14. Rapid detection and characterization of surface CO2 leakage through the real-time measurement of δ13C signatures in CO2 flux from the ground

    NASA Astrophysics Data System (ADS)

    Krevor, S.; Perrin, J.; Esposito, A.; Rella, C.; Benson, S. M.

    2009-12-01

    A portable stable carbon isotope ratio analyzer for carbon dioxide, based on wavelength scanned cavity ringdown spectroscopy, has been used to detect and characterize an intentional leakage of CO2 from an underground pipeline at the ZERT experimental facility in Bozeman, Montana. Rapid (~1 hour) walking surveys of the entire 100m x 100m site were collected using this mobile, real-time instrument. The resulting concentration and 13C isotopic abundance maps were processed using simple yet powerful analysis techniques, permitting not only the identification of specific leakage locations, but providing the ability to distinguish petrogenic sources of CO2 from biogenic sources. At the site an approximately 100-meter horizontal well has been drilled below an alfalfa field at a depth between 1-3 meters below the surface. The well has perforations along the central 70 meters of the well. The overlying strata are highly permeable sand, silt, and topsoil. The flora consists generally of long grasses and was cut to a height of less than 6 inches before the start of the experiment. For 30 days starting July 15, 2009, CO2 was injected at a rate of 0.2 tonnes per day. The injection rate is designed to simulate leakage from a mature storage reservoir at an annual rate of between .001 and .01%. The isotopic composition of the gas from the tank is at δ13C signature of approximately -52‰, far more negative than either atmospheric (approx. -8‰) or CO2 from soil respiration (approx. -26‰) at the site. The CO2 isotopic and concentration measurements were taken with a Picarro WS-CRDS analyzer with 1/8” tubing connected to a sampling inlet. Simultaneous with CO2 concentrations (including 13C), position data was logged using a GPS receiver. Datapoints are taken around every second. The analyzer was powered using batteries and housed in a conventional garden cart. The surveys consisted of traverses of the site along the length of the pipeline and extending out 100 meters on either

  15. Rapid detection and characterization of surface CO2 leakage through the real-time measurement of δ13C signatures in CO2 flux from the ground

    NASA Astrophysics Data System (ADS)

    Krevor, Samuel; Benson, Sally; Rella, Chris; Perrin, Jean-Christophe; Esposito, Ariel; Crosson, Eric

    2010-05-01

    characterize an intentional leakage of CO2 from an underground pipeline at the ZERT experimental facility in Bozeman, Montana. Rapid ( 1 hour) walking surveys of the entire 100m x 100m site were collected using this mobile, real-time instrument. The resulting concentration and 13C isotopic abundance maps were processed using simple yet powerful analysis techniques, permitting not only the identification of specific leakage locations, but providing the ability to distinguish petrogenic sources of CO2 from biogenic sources. At the site an approximately 100-meter horizontal well has been drilled below an alfalfa field at a depth between 1-3 meters below the surface. The well has perforations along the central 70 meters of the well. The overlying strata are highly permeable sand, silt, and topsoil. For 30 days starting July 15, 2009, CO2 was injected at a rate of 0.2 tonnes per day. The injection rate is designed to simulate leakage from a mature storage reservoir at an annual rate of between .001 and .01%. The isotopic composition of the gas from the tank is at δ13C signature of approximately -52 parts per thousand (per mil), far more negative than either atmospheric (approx. -8 per mil) or CO2 from soil respiration (approx. -26 per mil) at the site. The CO2 isotopic and concentration measurements were taken with a Picarro WS-CRDS analyzer with 1/8' tubing connected to a sampling inlet. Simultaneous with CO2 concentrations (including 13C), position data was logged using a GPS receiver. Datapoints are taken around every second. The analyzer was powered using batteries and housed in a mobile cart. The surveys consisted of traverses of the site along the length of the pipeline and extending out 100 meters on either side of the pipeline with the end of the gas inlet tube approximate 9 cm above the ground at a speed of 1-2m/sec. This simulates the type of survey that could be easily performed if the actual or potential site of a leak was known to within an area on the order of 100

  16. Characterization of focused seepage through an earthfill dam using geoelectrical methods.

    PubMed

    Ikard, S J; Revil, A; Schmutz, M; Karaoulis, M; Jardani, A; Mooney, M

    2014-01-01

    Resistivity and self-potential tomography can be used to investigate anomalous seepage inside heterogeneous earthen dams. The self-potential (SP) signals provide a unique signature to groundwater flow because the source current density responsible for the SP signals is proportional to the Darcy velocity. The distribution of the SP signals is also influenced by the distribution of the resistivity; therefore, resistivity and SP need to be used in concert to elucidate groundwater flow pathways. In this study, a survey is conducted at a small earthen dam in Colorado where anomalous seepage is observed on the downstream face at the dam toe. The data reveal SP and direct current resistivity anomalies that are used to delineate three anomalous seepage zones within the dam and to estimate the source of the localized seepage discharge. The SP data are inverted in two dimensions using the resistivity distribution to determine the distribution of the Darcy velocity responsible for the observed seepage. The inverted Darcy velocity agrees with an estimation of the Darcy velocity from the hydraulic conductivity obtained from a slug test and the observed head gradient.

  17. Characterization of a novel dissolved CO2 sensor for utilization in environmental monitoring and aquaculture industry

    NASA Astrophysics Data System (ADS)

    Balogh, K.; Jesus, João. M.; Gouveia, C.; Domingues, Jorge O.; Markovics, A.; Baptista, J. M.; Kovacs, B.; Pereira, Carlos M.; Borges, Maria-Teresa; Jorge, P. A. S.

    2013-11-01

    A novel optical fiber sensor is presented for measuring dissolved CO2 for water quality monitoring applications, where the optical signal is based either on refractive index changes or on color change. The sensing chemistry is based on the acid-basic equilibrium of 4-nitrophenol, that is converted into the anionic form by addition quaternary ammonium hydroxide. The CO2 sensitive layer was characterized and tested by using simple absorbance/reflectance measurement setups where the sensor was connected to a fiber optic CCD spectrometer. A prototype simulating a real shallow raceway aquaculture system was developed and its hydraulic behavior characterized. A commercially available partial-pressure- NDIR sensor was used as a reference for dissolved CO2 tests with the new optical fiber sensor under development. Preliminary tests allowed verifying the suitability of the new optical sensor for accurately tracking the dissolved carbon dioxide concentration in a suitable operation range. Direct comparison of the new sensor and the reference sensor system allowed to demonstrate the suitability of the new technology but also to identify some fragilities there are presently being addressed.

  18. Synthesis, Characterization, and Sensor Applications of Spinel ZnCo2O4 Nanoparticles

    PubMed Central

    Morán-Lázaro, Juan Pablo; López-Urías, Florentino; Muñoz-Sandoval, Emilio; Blanco-Alonso, Oscar; Sanchez-Tizapa, Marciano; Carreon-Alvarez, Alejandra; Guillén-Bonilla, Héctor; Olvera-Amador, María de la Luz; Guillén-Bonilla, Alex; Rodríguez-Betancourtt, Verónica María

    2016-01-01

    Spinel ZnCo2O4 nanoparticles were synthesized by means of the microwave-assisted colloidal method. A solution containing ethanol, Co-nitrate, Zn-nitrate, and dodecylamine was stirred for 24 h and evaporated by a microwave oven. The resulting solid material was dried at 200 °C and subsequently calcined at 500 °C for 5 h. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, confirming the formation of spinel ZnCo2O4 nanoparticles with average sizes between 49 and 75 nm. It was found that the average particle size decreased when the dodecylamine concentration increased. Pellets containing ZnCo2O4 nanoparticles were fabricated and tested as sensors in carbon monoxide (CO) and propane (C3H8) gases at different concentrations and temperatures. Sensor performance tests revealed an extremely high response to 300 ppm of CO at an operating temperature of 200 °C. PMID:27999315

  19. Structural, petrophysical and geomechanical characterization of the Becancour CO2 storage pilot site (Quebec, Canada)

    NASA Astrophysics Data System (ADS)

    Konstantinovskaya, E.; Malo, M.; Claprood, M.; Tran-Ngoc, T. D.; Gloaguen, E.; Lefebvre, R.

    2012-04-01

    The Paleozoic sedimentary succession of the St. Lawrence Platform was characterized to estimate the CO2 storage capacity, the caprock integrity and the fracture/fault stability at the Becancour pilot site. Results are based on the structural interpretation of 25 seismic lines and analysis of 11 well logs and petrophysical data. The three potential storage units of Potsdam, Beekmantown and Trenton saline aquifers are overlain by a multiple caprock system of Utica shales and Lorraine siltstones. The NE-SW regional normal faults dipping to the SE affect the subhorizontal sedimentary succession. The Covey Hill (Lower Potsdam) was found to be the only unit with significant CO2 sequestration potential, since these coarse-grained poorly-sorted fluvial-deltaic quartz-feldspar sandstones are characterized by the highest porosity, matrix permeability and net pay thickness and have the lowest static Young modulus, Poisson's ratio and compressive strength relative to other units. The Covey Hill is located at depths of 1145-1259 m, thus injected CO2 would be in supercritical state according to observed salinity, temperature and fluid pressure. The calcareous Utica shale of the regional seal is more brittle and has higher Young modulus and lower Poisson's ratio than the overlying Lorraine shale. The 3D geological model is kriged using the tops of the geological formations recorded at wells and picked travel times as external drift. The computed CO2 storage capacity in the Covey Hill sandstones is estimated by the volumetric and compressibility methods as 0.22 tons/km2 with storage efficiency factor E 2.4% and 0.09 tons/km2 with E 1%, respectively. A first set of numerical radial simulations of CO2 injection into the Covey Hill were carried out with TOUGH2/ECO2N. A geomechanical analysis of the St. Lawrence Platform sedimentary basin provides the maximum sustainable fluid pressures for CO2 injection that will not induce tensile fracturing and shear reactivation along pre

  20. Deep microbial life in the Altmark natural gas reservoir: baseline characterization prior CO2 injection

    NASA Astrophysics Data System (ADS)

    Morozova, Daria; Shaheed, Mina; Vieth, Andrea; Krüger, Martin; Kock, Dagmar; Würdemann, Hilke

    2010-05-01

    Within the framework of the CLEAN project (CO2 Largescale Enhanced gas recovery in the Altmark Natural gas field) technical basics with special emphasis on process monitoring are explored by injecting CO2 into a gas reservoir. Our study focuses on the investigation of the in-situ microbial community of the Rotliegend natural gas reservoir in the Altmark, located south of the city Salzwedel, Germany. In order to characterize the microbial life in the extreme habitat we aim to localize and identify microbes including their metabolism influencing the creation and dissolution of minerals. The ability of microorganisms to speed up dissolution and formation of minerals might result in changes of the local permeability and the long-term safety of CO2 storage. However, geology, structure and chemistry of the reservoir rock and the cap rock as well as interaction with saline formation water and natural gases and the injected CO2 affect the microbial community composition and activity. The reservoir located at the depth of about 3500m, is characterised by high salinity fluid and temperatures up to 127° C. It represents an extreme environment for microbial life and therefore the main focus is on hyperthermophilic, halophilic anaerobic microorganisms. In consequence of the injection of large amounts of CO2 in the course of a commercial EGR (Enhanced Gas Recovery) the environmental conditions (e.g. pH, temperature, pressure and solubility of minerals) for the autochthonous microorganisms will change. Genetic profiling of amplified 16S rRNA genes are applied for detecting structural changes in the community by using PCR- SSCP (PCR-Single-Strand-Conformation Polymorphism) and DGGE (Denaturing Gradient Gel Electrophoresis). First results of the baseline survey indicate the presence of microorganisms similar to representatives from other saline, hot, anoxic, deep environments. However, due to the hypersaline and hyperthermophilic reservoir conditions, cell numbers are low, so that

  1. CO2-induced dissolution of low permeability carbonates. Part I: Characterization and experiments

    NASA Astrophysics Data System (ADS)

    Smith, Megan M.; Sholokhova, Yelena; Hao, Yue; Carroll, Susan A.

    2013-12-01

    The effect of elevated dissolved CO2 concentrations on compositionally and structurally distinct carbonate sample cores from the Weyburn-Midale CO2-enhanced oil recovery and storage site (Canada) was measured from analysis of 3-D sample characterization and fluid chemistry data from core-flood experiments. Experimental conditions (60 °C; 24.8 MPa confining pressure) and brine composition were chosen to mimic in situ reservoir conditions. Mineralogy and pore space distributions within the eight individual cores were characterized with X-ray computed microtomography and scanning electron microscopy both before and after exposure to brine with 0.5 ⩽ pCO2 ⩽ 3 MPa, while solution chemistry and differential fluid pressures were monitored during experiments. Our experimental study aimed to quantify the relationship between fluid flow, heterogeneity, and reaction specific to carbon storage at the Weyburn-Midale field by integrating characterization imaging, pressure data, and solution chemistry. Through the use of non-invasive microtomographic imaging, a variety of dissolution behaviors were observed, with variable effects on the evolution of solution chemistry and permeability as a result of heterogeneity within these two relatively low permeability carbonate samples. Similar-sized, evenly distributed pores, and steadily advancing dissolution fronts suggested that uniform flow velocities were maintained throughout the duration of the higher permeability “Marly” dolostone core experiments. The development of unstable dissolution fronts and fast pathways occurred in the “Vuggy” sample experiments when fluid velocities varied widely within the sample (as a result of increased pore structure heterogeneity). The overall effect of fast pathway development was to increase bulk permeability values by several orders of magnitude, allowing CO2-acidified fluids to travel through the cores largely unmodified by carbonate mineral reaction, as indicated by a lack of change

  2. InGaAsSb Detectors' Characterization for 2-Micron CO2 Lidar/DIAL Applications

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Abedin, M. Nurul; Koch, Grady J.; Singh, Upendra N.

    2003-01-01

    Recent interest in monitoring atmospheric CO2 focuses attention on infrared remote sensing using the 2-micron lidar/differential absorption lidar (DIAL) technique. Quantum detectors are critical components in this technique, and many research efforts concentrate on developing such devices for the 2-micron wavelength. Characterization results of InGaAsSb quantum detectors for the 2-micron wavelength range are presented, including experimental setup and procedure. Detectors are prototype devices manufactured by using separate absorption and multiplication (SAM) structures. Characterization experiments include V-I measurements, spectral response and its variation with bias voltage and temperature, noise measurements, noise-equivalent-power (NEP) and detectivity calculations, and signal-to-noise ratio (SNR) estimation. A slight increase in the output signal occurred with increased bias voltage and was associated with a noise level increase. Cooling down the detectors reduces noise and shifts the cutoff wavelength to shorter values. Further improvement in the design and manufacturing process, by increasing the device gain and lowering its noise level, is necessary to meet the required CO2 lidar/DIAL specifications.

  3. CO2 sequestration in deep coal seams: experimental characterization of the fundamental underlying mechanisms

    NASA Astrophysics Data System (ADS)

    Pini, R.; Mazzotti, M.

    2012-04-01

    The process of injecting and storing carbon dioxide (CO2) into suitable deep geological formations, such as saline aquifers, (depleted) oil or gas reservoirs, and unmineable coal seams, is referred to as CO2 sequestration. In little more than a decade, this technology has emerged as one of the most important options for reducing CO2 emissions. Among the different options, unmineable coal seams are not as broadly distributed as saline aquifers or oil/gas reservoirs, but their peculiarity resides in the proven capacity of retaining significant amount of gas (mainly methane, CH4) for a very long time. Additionally, the injection of CO2 into the coal reservoir would enhance the recovery of this natural gas, a source of energy that will most likely play a key role in the power sector over the next 20 years from now. This process is called Enhanced Coal Bed Methane (ECBM) recovery and, as for enhanced oil recovery, it allows in principle offsetting the costs associated to the storage operation. A study was undertaken aimed at the experimental characterization of the fundamental mechanisms that take place during the process of injection and storage in coal reservoirs, namely adsorption and swelling (Pini et al 2010), and of their effects on the coal's permeability (Pini et al. 2009), the property that plays a dominant role in controlling fluid transport in a porous rock. An apparatus has been built that allows measuring the permeability of rock cores under typical reservoir conditions (high pressure and temperature) by the so-called transient step method. For this study, a coal core from the Sulcis coal mine in Sardinia (Italy) has been used. In the experiments, an inert gas (helium) was used to investigate the effects of the effective pressure on the permeability of the coal sample, whereas two adsorbing gases (CO2 and N2) to quantify those of adsorption and swelling. The experiments have been interpreted by a one-dimensional model that describes the fluid transport

  4. Characterization of Tropospheric Emission Spectrometer (TES) CO2 for carbon cycle science

    NASA Astrophysics Data System (ADS)

    Kulawik, S. S.; Jones, D. B. A.; Nassar, R.; Irion, F. W.; Worden, J. R.; Bowman, K. W.; Machida, T.; Matsueda, H.; Sawa, Y.; Biraud, S. C.; Fischer, M.; Jacobson, A. R.

    2009-12-01

    We present carbon dioxide (CO2) estimates from the Tropospheric Emission Spectrometer (TES) on the EOS-Aura satellite launched in 2004. For observations between 40° S and 45° N, we find about 1 degree of freedom with peak sensitivity at 511 hPa. The estimated error is ~10 ppm for a single target and about 1.3 ppm for monthly averages on spatial scales of 20°×30°. Monthly spatially-averaged TES results from 2005-2008 processed with a uniform initial guess and prior are compared to CONTRAIL aircraft data over the Pacific ocean, aircraft data at the Southern Great Plains (SGP) ARM site in the southern US, and the Mauna Loa and Samoa surface stations. Comparisons to Mauna Loa observatory show a correlation of 0.92, a standard deviation of 1.3 ppm, a predicted error of 1.2 ppm, and a ~2% low bias, which is subsequently corrected, and comparisons to SGP aircraft data over land show a correlation of 0.67 and a standard deviation of 2.3 ppm. TES data between 40° S and 45° N for 2006-2007 are compared to surface flask data, GLOBALVIEW, the Atmospheric Infrared Sounder (AIRS), and CarbonTracker. Comparison to GLOBALVIEW-CO2 ocean surface sites shows a correlation of 0.60 which drops when TES is offset in latitude, longitude, or time. At these same locations, TES shows a 0.62 and 0.67 correlation to CarbonTracker with TES observation operator at the surface and 5 km, respectively. We also conducted an observing system simulation experiment to assess the potential utility of the TES data for inverse modeling of CO2 fluxes. We find that if biases in the data and model are well characterized, the averaged data have the potential to provide sufficient information to significantly reduce uncertainty on annual estimates of regional CO2 sources and sinks. Averaged pseudo-data at 10°×10° reduced uncertainty in flux estimates by as much as 70% for some tropical regions.

  5. Characterization of Tropospheric Emission Spectrometer (TES) CO2 for carbon cycle science

    NASA Astrophysics Data System (ADS)

    Kulawik, S. S.; Jones, D. B. A.; Nassar, R.; Irion, F. W.; Worden, J. R.; Bowman, K. W.; Machida, T.; Matsueda, H.; Sawa, Y.; Biraud, S. C.; Fischer, M. L.; Jacobson, A. R.

    2010-06-01

    We present carbon dioxide (CO2) estimates from the Tropospheric Emission Spectrometer (TES) on the EOS-Aura satellite launched in 2004. For observations between 40° S and 45° N, we find about 1 degree of freedom with peak sensitivity at 511 hPa. The estimated error is ~10 ppm for a single target and 1.3-2.3 ppm for monthly averages on spatial scales of 20°×30°. Monthly spatially-averaged TES data from 2005-2008 processed with a uniform initial guess and prior are compared to CONTRAIL aircraft data over the Pacific ocean, aircraft data at the Southern Great Plains (SGP) ARM site in the southern US, and the Mauna Loa and Samoa surface stations. Comparisons to Mauna Loa data show a correlation of 0.92, a standard deviation of 1.3 ppm, a predicted error of 1.2 ppm, and a ~2% low bias, which is subsequently corrected. Comparisons to SGP aircraft data over land show a correlation of 0.67 and a standard deviation of 2.3 ppm. TES data between 40° S and 45° N for 2006-2007 are compared to surface flask data, GLOBALVIEW, the Atmospheric Infrared Sounder (AIRS), and CarbonTracker. Comparison to GLOBALVIEW-CO2 ocean surface sites shows a correlation of 0.60 which drops when TES is offset in latitude, longitude, or time. At these same locations, TES shows a 0.62 and 0.67 correlation to CarbonTracker at the surface and 5 km, respectively. We also conducted an observing system simulation experiment to assess the potential utility of the TES data for inverse modeling of CO2 fluxes. We find that if biases in the data and model are well characterized, the averaged data have the potential to provide sufficient information to significantly reduce uncertainty on annual estimates of regional CO2 sources and sinks. Averaged pseudo-data at 10°×10° reduced uncertainty in flux estimates by as much as 70% for some tropical regions.

  6. Supercritical CO2 extract of Cinnamomum zeylanicum: chemical characterization and antityrosinase activity.

    PubMed

    Marongiu, Bruno; Piras, Alessandra; Porcedda, Silvia; Tuveri, Enrica; Sanjust, Enrico; Meli, Massimo; Sollai, Francesca; Zucca, Paolo; Rescigno, Antonio

    2007-11-28

    The volatile oil of the bark of Cinnamomum zeylanicum was extracted by means of supercritical CO2 fluid extraction in different conditions of pressure and temperature. Its chemical composition was characterized by GC-MS analysis. Nineteen compounds, which in the supercritical extract represented >95% of the oil, were identified. (E)-Cinnamaldehyde (77.1%), (E)-beta-caryophyllene (6.0%), alpha-terpineol (4.4%), and eugenol (3.0%) were found to be the major constituents. The SFE oil of cinnamon was screened for its biological activity about the formation of melanin in vitro. The extract showed antityrosinase activity and was able to reduce the formation of insoluble flakes of melanin from tyrosine. The oil also delayed the browning effect in apple homogenate. (E)-Cinnamaldehyde and eugenol were found to be mainly responsible of this inhibition effect.

  7. Characterization of amine-functionalized electrode for aqueous carbon dioxide (CO2) direct detection

    NASA Astrophysics Data System (ADS)

    Sato, Hiroshi

    2017-03-01

    In this study, fabrication of amino groups and ferrocenes co-modified sensor electrode and electrochemical detection of carbon dioxide (CO2) in the saline solution is reported. Electrochemical detection of CO2 was carried out using cyclic voltammetry in saline solution containing sodium bicarbonate as CO2 source. Oxidation and reduction peak current intensities computed from cyclic voltammograms varied as a function of concentration of CO2 molecules. The calibration curve was obtained by plotting oxidation peak current intensities as a function of CO2 concentration. The sensor electrode prepared in this study can estimate the differences between concentrations of CO2 in normal seawater up to 10 times higher. Furthermore, the surface analysis was performed to clarify the CO2 detection mechanism.

  8. Preliminary Geophysical Characterization of a CO2-Driven Geyser in the Rio Grande Rift, New Mexico

    NASA Astrophysics Data System (ADS)

    Feucht, D. W.; Jensen, K. J.; Kelly, C.; Ryan, J. C.; Ferriz, H.; Kanjorski, N.; Ferguson, J. F.; McPhee, D. K.; Pellerin, L.

    2009-12-01

    As part of the Summer of Applied Geophysical Experience (SAGE) a preliminary geophysical investigation was conducted in the vicinity of a cold CO2-driven geyser located at Chimayó, NM, along the eastern margin of the Rio Grand Rift. This geyser is of interest as a possible analog for CO2 leakage from deep saline-aquifer carbon sequestration projects. Observed water chemistry variations can be explained by mixing of a CO2-rich, high salinity brine rising into, and mixing with a shallow freshwater aquifer. Several large, basin bounding faults and numerous smaller normal faults cut the area of the well and may constitute the necessary conduit for the deep water. Geophysical methods were used to characterize the subsurface properties at the Chimayó geyser as well as regional structures that may influence groundwater flow in the area. Shallow transient electromagnetic (TEM) data and capactively-coupled resistivity (CCR) data were acquired in close proximity to the geyser. The CCR shows a near-surface resistive feature, possibly hematite-cemented Tesuque formation sediment, in close proximity to the geyser. A shallow, highly conductive layer delineated through modeling of the TEM data is postulated to be a fluid consistent with high levels of Total Dissolved Solid (TDS) content. The well is located almost directly on the Roberts fault, which is antithetic to the basin bounding Chimayó fault 1.5 km to the east. Previously published hydrogeochemical studies associate this fault with high CO2 and TDS water along its strike. Deeper sounding TEM and audiomagnetotelluric (AMT) data were acquired along the Alamo Arroyo, 3 km to the southwest of the well. The Kelley Federal #1 Well located in this arroyo provides deep stratigraphic control to Pennsylvanian carbonate basement at 740 m. Tesuque formation conglomeritic alluvial fan deposits occur between 230 and 708 m and are overlain by finer grained basin floor deposits. The deep, coarse grained unit is thought to be a good

  9. Characterizing near-surface CO2 conditions before injection - Perspectives from a CCS project in the Illinois Basin, USA

    USGS Publications Warehouse

    Locke, R.A.; Krapac, I.G.; Lewicki, J.L.; Curtis-Robinson, E.

    2011-01-01

    The Midwest Geological Sequestration Consortium is conducting a large-scale carbon capture and storage (CCS) project in Decatur, Illinois, USA to demonstrate the ability of a deep saline formation to store one million tonnes of carbon dioxide (CO2) from an ethanol facility. Beginning in early 2011, CO2 will be injected at a rate of 1,000 tonnes/day for three years into the Mount Simon Sandstone at a depth of approximately 2,100 meters. An extensive Monitoring, Verification, and Accounting (MVA) program has been undertaken for the Illinois Basin Decatur Project (IBDP) and is focused on the 0.65 km2 project site. Goals include establishing baseline conditions to evaluate potential impacts from CO2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO2. MVA efforts are being conducted pre-, during, and post- CO2 injection. Soil and net CO2 flux monitoring has been conducted for more than one year to characterize near-surface CO2 conditions. More than 2,200 soil CO2 flux measurements have been manually collected from a network of 118 soil rings since June 2009. Three ring types have been evaluated to determine which type may be the most effective in detecting potential CO 2 leakage. Bare soil, shallow-depth rings were driven 8 cm into the ground and were prepared to minimize surface vegetation in and near the rings. Bare soil, deep-depth rings were prepared similarly, but were driven 46 cm. Natural-vegetation, shallow-depth rings were driven 8 cm and are most representative of typical vegetation conditions. Bare-soil, shallow-depth rings had the smallest observed mean flux (1.78 ??mol m-2 s-1) versus natural-vegetation, shallow-depth rings (3.38 ??mol m-2 s-1). Current data suggest bare ring types would be more sensitive to small CO2 leak signatures than natural ring types because of higher signal to noise ratios. An eddy covariance (EC) system has been in use since June

  10. Workflow Integrating Fracture Permeability Characterization and Multiphase Flow Modeling for CO2 Storage and Risk Assessments in Fractured Reservoirs

    NASA Astrophysics Data System (ADS)

    Jin, G.; Pashin, J. C.

    2014-12-01

    Ensuring safe and permanent storage of sequestered CO2in naturally fractured geological media is vital for the success of geologic storage projects. Critical needs exist to develop advanced techniques to characterize and model fluid transport in naturally fractured reservoirs and seals. We have developed a scale-independent 3-D stochastic fracture permeability characterization workflow that employs multiple discrete fracture network (DFN) realizations. The workflow deploys a multidirectional flux-based upwind weighting scheme that is capable of modeling multiphase flow in highly heterogeneous fractured media. The techniques employed herein show great promise for increasing the accuracy of capacity determinations and the prediction of pressure footprints associated with injected CO2 plumes. The proposed workflow has been conducted in a simulation study of flow transport and risk assessment of CO2 injection into a deep fractured saline formation using geological parameters from Knox Group carbonate and Red Mountain shale rocks in central Alabama. A 3-D fracture permeability map was generated from multiple realizations of DFN models. A multiphase flow model composed of supercritical CO2 and saline water was applied to simulate CO2 plume evolution during and after injection. Injection simulation reveals significant permeability anisotropy that favors development of northeast-elongate CO2 plumes. The spreading front of the CO2 plume shows strong viscous fingering effects. Post-injection simulation indicates significant lateral spreading of CO2 near the top of the fractured formations because of the buoyancy of injectate in rock matrix and strata-bound vertical fractures. Risk assessment shows that although pressure drops faster in the fractured formations than in those lacking fractures, lateral movement of CO2 along natural fractures necessitates that the injectate be confined by widespread seals with high integrity.

  11. Geophysical Characterization for a CO2 Sequestration Potential in the Ohio River Valley Region

    NASA Astrophysics Data System (ADS)

    Gupta, N.; Jagucki, P.; Meggyesy, D.; Janosy, R.; Sminchak, J.; Ramakrishan, T.; Boyd, A.

    2003-12-01

    A site at the American Electric Power's (AEP) Mountaineer Power Plant, WV in the Ohio River Valley in the Midwestern U.S., a region with the economy heavily dependent on fossil fuels, such as coal, oil, and gas, is being evaluated to determine the potential for geologic sequestration. The project is supported by the U.S. Department of Energy, Battelle, AEP, BP, The Ohio Air Quality Development Office, and Schlumberger. The major objective of the current phase is to characterize the reservoir at the plant site. Future decisions with regard to CO2 injection will be subject to the evaluated reservoir properties. The effort includes acquisition of 2-dimensional seismic data, assessment of regional geology, drilling to PreCambrian rocks and formation analysis and testing in a 2,800 meters deep well, reservoir simulations, risk assessment, and stakeholder outreach. The test well reached total depth in summer 2003. Wireline logging and reservoir testing was performed for each section of the borehole, including extensive tests in the lowermost 885 meters to estimate formation properties and pressure gradients. The logs included gamma-ray, neutron and density, and array resistivity, magnetic resonance relaxation for permeability information, elemental composition via capture spectroscopy, and resistivity based formation image. The seismic survey was conducted over approximately 11 miles along 2 lines: one along strike and one along dip. The results of the geophysical surveys combined with the field observations provide an integrated assessment of the major injection parameters for the two main injection reservoirs of interest, the Rose Run Formation and the Lower Maryville formation. In addition, the properties of the potential caprock formations overlying the candidate injection zones were also determined. The results of this characterization will be presented with emphasis on geophysical testing and seismic survey. These results are also being used to conduct reservoir

  12. Utilizing Continuous Resistivity Profiling for Assessment and Characterization of Canal Seepage in El Paso's Lower Valley Irrigation Network System

    NASA Astrophysics Data System (ADS)

    Brown, W. A.; Sheng, Z.

    2009-12-01

    Annually, billions of gallons of water are lost through seepage along sections of the irrigation network. To conserve water, El Paso County Water Improvement District has been assessing seepage losses and investigating measures for reducing such losses. Resistivity techniques were used to identify areas of high seepage and provide information on locations along canals that need to be structurally modified in an effort to curb water lost through seepage. Several half mile sections were selected along canals with varying seepage rates to conduct electric resistivity surveys in order generate soil profiles during the non-irrigation and irrigation seasons. Two different multiple channel resistivity meters (The“OhmMapper and the Super Sting R8”) were used, which both allow a vertical resistivity profile to be collected using a single current transmission. The results presented are preliminary and we believe that upon completion findings will serve multiple purposes. Firstly, a better understanding of seepage patterns, seepage rate and its spatial variation can be obtained. Secondly, our findings could be used to produce geological profiles associated with seepage areas which will enable the irrigation district to develop guidelines for improving delivery efficiency, especially during drought. And thirdly, our results will be transferable to other areas of the state and will have a positive impact on the environment and the overall quality of life.

  13. Characterization of CO2 flow in a hypersonic impulse facility using DLAS

    NASA Astrophysics Data System (ADS)

    Meyers, J. M.; Paris, S.; Fletcher, D. G.

    2016-02-01

    This work documents diode laser absorption measurements of CO2 flow in the free stream of the Longshot hypersonic impulse facility at Mach numbers ranging from 10 to 12. The diode laser sensor was designed to measure absorption of the P12 (30013) ← (00001) transition near 1.6 \\upmum, which yields relatively weak direct absorption levels (3.5 % per meter at peak Longshot free-stream conditions). Despite this weak absorption, measurements yielded valuable flow property information during the first 20 ms of facility runs. Simultaneous measurements of static temperature, pressure, and velocity were acquired in the inviscid core flow region using a laser wavelength scanning frequency of 600 Hz. The free-stream values obtained from DLAS measurements were then compared to Longshot probe-derived values determined from settling chamber and probe measurements. This comparison enabled an assessment of the traditional method of flow characterization in the facility, which indicated negligible influence from possible vibrational freezing of reservoir gases.

  14. Characterization of gypsum crystals exposed to a high CO2 concentration fog using x-ray

    NASA Astrophysics Data System (ADS)

    Carreño-Márquez, I. J. A.; Castillo-Sandoval, I.; Esparza-Ponce, H. E.; Fuentes-Cobas, L.; Montero-Cabrera, M. E.

    2015-07-01

    In Chihuahua State, a little town called Naica has the largest gypsum single crystals in the world. The growth of these structures has been described as a long and stable process developed over thousands of years. Due to the change in the environmental conditions, these crystals could suffer alterations on their surface. In this project we study the cause of possible deterioration of the giant crystals and intend to suggest measures for their preservation. For this sake, our first experiment consists on several gypsum crystals that have been subjected in a climate chamber to a fog at high CO2 concentration and 51 °C for a period of time of six months, extracting two crystals every 15 days. Then the crystals have been characterized through Grazing Incidence X-Ray Diffraction using a diffractometer PanAlytical X'PertPro with two different detectors; Xe-filled proportional detector and a Pixel 3D detector. The results were compared to determine which technique is the most suitable to study the degradation of gypsum single crystals. In the two cases, we have identified only the gypsum phase, but with different crystal plane orientations.

  15. Fractal characterization of seepage-pores of coals from China: An investigation on permeability of coals

    NASA Astrophysics Data System (ADS)

    Yao, Yanbin; Liu, Dameng; Tang, Dazhen; Tang, Shuheng; Huang, Wenhui; Liu, Zhihua; Che, Yao

    2009-06-01

    To better understand the characteristics of seepage-pores (pore radius larger than 100 nanometers) and their influence on the permeability of coals, we have conducted fractal analyses for 34 fresh coal samples (mean maximum vitrinite reflectance Ro,max from 0.43% to 4.21%) from North, Northwest and Northeast China. Mercury porosimetry data indicate that the coals are fractal, with pore radius ranging from 0.1 to 50 μm. Calculated fractal dimensions of these coals range from 2.61 to 2.98, higher than those from other kinds of rocks such as sandstone, shale, and carbonate. The data suggest that the coals have more complicated and inhomogeneous pore structures than other rocks. The fractal dimension has a negative correlation with the petrologic permeability of coals, particularly for higher rank coals (with 1.47-4.21% Ro,max), from which a strong negative linear correlation ( R2=0.85) between fractal dimension and permeability is observed. A 'U-shaped' trend between fractal dimensions and coal ranks is observed, with the minimum fractal dimensions occurring at 1.1-1.3% Ro,max. The sub-bituminous, high volatile bituminous, semi-anthracite, and anthracite have higher fractal dimensions. The effects of coal rank upon fractal dimensions are mainly due to the variety of micropore contents and aromaticity of coals with coalification.

  16. Postsynthetic Functionalization of Mg-MOF-74 with Tetraethylenepentamine: Structural Characterization and Enhanced CO2 Adsorption.

    PubMed

    Su, Xiao; Bromberg, Lev; Martis, Vladimir; Simeon, Fritz; Huq, Ashfia; Hatton, T Alan

    2017-03-15

    Postsynthetic functionalization of magnesium 2,5-dihydroxyterephthalate (Mg-MOF-74) with tetraethylenepentamine (TEPA) resulted in improved CO2 adsorption performance under dry and humid conditions. XPS, elemental analysis, and neutron powder diffraction studies indicated that TEPA was incorporated throughout the MOF particle, although it coordinated preferentially with the unsaturated metal sites located in the immediate proximity to the surface. Neutron and X-ray powder diffraction analyses showed that the MOF structure was preserved after amine incorporation, with slight changes in the lattice parameters. The adsorption capacity of the functionalized amino-Mg-MOF-74 (TEPA-MOF) for CO2 was as high as 26.9 wt % versus 23.4 wt % for the original MOF due to the extra binding sites provided by the multiunit amines. The degree of functionalization with the amines was found to be important in enhancing CO2 adsorption, as the optimal surface coverage improved performance and stability under both pure CO2 and CO2/H2O coadsorption, and with partially saturated surface coverage, optimal CO2 capacity could be achieved under both wet and dry conditions by a synergistic binding of CO2 to the amines as well as metal centers.

  17. EM Methods Applied for the Characterization and Monitoring of the Hontomin (Spain) CO2 Storage Pilot Plant

    NASA Astrophysics Data System (ADS)

    Ledo, Juanjo; Queralt, Pilar; Marcuello, Alex; Ogaya, Xenia; Vilamajo, Eloi; Bosch, David; Escalas, Lena; Piña, Perla

    2013-04-01

    The work presented here correspond to an on-going project in the frame of the development of a pilot plant for CO2 storage in a deep saline aquifer funded by Fundación Ciudad de la Energía-CIUDEN (http://www.ciuden.es/) on behalf of the Spanish Government. The main objective of the research Project is to monitor the CO2 migration within the reservoir during and after the injection as well as testing and evaluating different EM monitoring methods. In this way, a good characterization of the zone is imperative to perceive and quantify, as soon as possible, any change owing to the CO2 injection. Among all geophysical techniques, electrical and electromagnetic methods are especially useful and meaningful to monitor the CO2 plume since these methods are sensitive to the electrical conductivity of the pore fluid. The presence of CO2 inside the pore will replace a fraction of saline fluid within the storage aquifer, reducing the effective volume available for ionic transport. As a consequence, the bulk electrical resistivity of the rock is expected to increase significantly. The proposed EM techniques are the following: 1- Magnetotelluric method, 2-Cross-hole electrical resistivity tomography, 3- Control source electromagnetics. Moreover laboratory experiments are being carried out to monitor the CO2 flux inside sample cores using ERT.

  18. Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

    NASA Astrophysics Data System (ADS)

    Santillan, Eugenio Felipe; Shanahan, Timothy; Omelon, Christopher; Major, Jonathan; Bennett, Philip

    2015-07-01

    When CO2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO2- rich spring considered a carbon sequestration analogue, was characterized. The isolate was cultured under varying CO2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs) to elucidate growth conditions and metabolic activity. Designated CG-1, the isolate is related (99%) to Lactobacillus casei in 16S rRNA gene identity, growing at PCO2 between 0 to 1.0 MPa. Growth is inhibited at 2.5 MPa, but stationary phase cultures exposed to this pressure survive beyond 5 days. At 5.0 MPa, survival is at least 24 hours. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° to 45°C andconsumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 MPa to 1.0 MPa suggests decreases in cell size and increases in membrane rigidity. Transmission electron microscopy reveals rod shaped bacteria at 0.1 MPa. At 1.0 MPa, cells are smaller, amorphous, and produce abundant capsular material. Its ability to grow in environments regardless of the presence of CO2 suggests we have isolated an organism that is more capnotolerant than capnophilic. Results also show that microorganisms are capable of surviving the stressful conditions created by the introduction of CO2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the surrounding environment.

  19. Preparation and characterization of amine-functionalized sugarcane bagasse for CO2 capture.

    PubMed

    Luo, Shihe; Chen, Siyu; Chen, Shuixia; Zhuang, Linzhou; Ma, Nianfang; Xu, Teng; Li, Qihan; Hou, Xunan

    2016-03-01

    A low-cost solid amine adsorbent for CO2 capture was prepared by using sugarcane bagasse (SB), a dominant agro-industrial residue in the sugar and alcohol industry as raw materials. In this preparation process, acrylamide was grafted on SB, and the grafted fiber was then aminated with different type of amine reagents to introduce primary and secondary amine groups onto the surface of SB fibers. The graft and amination conditions were optimized. The prepared solid amine adsorbent showed remarkable CO2 adsorption capacity and the adsorption capacity of the solid amine adsorbent could reach 5.01 mmol CO2/g at room temperature. The comparison of adsorption capacities of amine fibers aminated with various amination agents demonstrated that fibers aminated with triethylenetetramine would obtain higher adsorption capacities and higher amine efficiency. These adsorbents also showed good regeneration performance, the regenerated adsorbent could maintain almost the same adsorption capacity for CO2 after 10 recycles.

  20. Advanced Reservoir Characterization and Evaluation of CO2 Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III

    SciTech Connect

    Knight, Bill; Schechter, David S.

    2002-07-26

    The goal of this project was to assess the economic feasibility of CO2 flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. This provides results of the final year of the six-year project for each of the four areas.

  1. Advanced Reservoir Characterization and Evaluation of CO2 Gravity Drainage in the Naturally Fractured Spraberry Trend Area

    SciTech Connect

    McDonald, Paul; Schechter, David S.

    1999-11-01

    The overall goal of this project was to assess the economic feasibility of CO2 flooding the naturally fractured Spraberry Trend Area in West Texas. This objective was accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. Additionally, a ten (10) acre field demonstration pilot project is part of this project. This report discusses the activity, during the third calendar quarter (July through September) of 1998 (fourth quarter of the projects fiscal year).

  2. Characterization of atmosphere-water exchange processes of CO 2 in estuaries using dynamic simulation

    NASA Astrophysics Data System (ADS)

    García-Luque, E.; Forja, J. M.; Gómez-Parra, A.

    2005-12-01

    CO 2 is one of the so-called "greenhouse effect" gases; therefore, its rates of water-atmosphere exchange are very relevant for studies of climate change. Coastal zones (which include estuarine systems) are of special interest in relation to the global carbon cycle. Thus, an estuary simulator, which operates in a dynamic mixing regime, is specifically applied in an initial study of the estuarine dynamic of inorganic carbon, focusing basically on the influence of salinity and pH on the water-atmosphere fluxes of CO 2 in these zones. The simulation has been performed under two assumptions: (i) considering that the system is subjected to a stationary gradient of salinity and (ii) taking into account the effect of the tides, owing to the daily oscillations introduced by this phenomenon in the process of CO 2 transfer between the water and the atmosphere. After analysing the results, it has been observed that a potential source of error exists when choosing the coefficients of gas exchange ( k) for CO 2 studies. Nevertheless, the evolution of CO 2 fluxes along the salinity and pH gradients achieved shows the same trends with those observed in a wide variety of real estuaries described in the related literature.

  3. Synthesis and characterization of mesoporous spinel NiCo2O4 using surfactant-assembled dispersion for asymmetric supercapacitors

    NASA Astrophysics Data System (ADS)

    Hsu, Chun-Tsung; Hu, Chi-Chang

    2013-11-01

    A simple and scalable process has been developed for synthesizing spinel NiCo2O4 nanocrystals through a thermal decomposition method. The introduction of hexadecyltrimethylammonium bromide (CTAB, (C16H33)N(CH3)3Br) into precursor solutions significantly enhances the homogeneity and porosity of spinel NiCo2O4. The porosity and high specific surface area of NiCo2O4 preserves the brilliant pseudo-capacitive performances due to providing smooth paths for electrolyte penetration and ion diffusion into inner active sites. Morphologies and microstructures of the active materials are examined by transmission electron microscopic (TEM) and X-ray diffraction (XRD) analyses. Thermogravimetric analysis (TGA) is used to evaluate the thermal properties of precursor solutions. The electrochemical performances of NiCo2O4 are systematically characterized by cyclic voltammetry and charge-discharge tests. Asymmetric supercapacitors are assembled with these brilliant binary oxides as the positive electrode and activated carbon as the negative electrode. The highly porous NiCo2O4 exhibits superior capacitive performances, i.e., high specific capacitance (764 F g-1 at 2 mV s-1) and long cycle life.

  4. Isolation and Characterization of a Novel CO2-Tolerant Lactobacillus Strain from Crystal Geyser, UT

    NASA Astrophysics Data System (ADS)

    Santillan, E. U.; Major, J. R.; Omelon, C. R.; Shanahan, T. M.; Bennett, P.

    2013-12-01

    Capnophiles are microbes that grow in CO2 enriched environments. Cultured capnophiles generally, grow in 2 to 25% CO2, or 0.02 to 0.25 atm. When CO2 is sequestered in deep saline aquifers, the newly created high CO2 environment may select for capnophlic organisms. In this study, a capnophile was isolated from Crystal Geyser, a CO2 spring along the Little Grand Wash Fault, UT, a site being investigated as an analogue to CO2 sequestration. Crystal Geyser periodically erupts with CO2 charged water, indicating the presence of very high CO2 pressures below the subsurface, similar to sequestration conditions. Biomass was sampled by pumping springwater from approximately 10 m below the surface through filters. Filters were immediately placed in selective media within pressure vessels where they were pressurized to 10 atm in the field. Subsequent recultures produced an isolate, designated CG-1, that is most closely (99%) related to Lactobacillus casei on the strain level. CG-1 grows in tryptic soy broth, in PCO2 ranging from 0 atm to 10 atm, 40 times higher than pressures of previously cultured capnophiles. At 25 atm, growth is inhibited though survival can be as long as 5 days. At 50 atm, survival is poor, with sterilization occurring by 24 hours. Growth is optimal between pH values of 6 to 8, though sluggish if no CO2 is present. Its optimal salinity is 0.25 M NaCl though growth is observed ranging from 0 to 1 M NaCl. Growth is observed between 25o to 45o C, but optimal at 25oC. It consumes long-chained carbon molecules such as glucose, sucrose, and crude oil, and exhibits poor growth when supplied with lactate, acetate, formate, and pyruvate. The organism likely performs lactic acid fermentation as it requires no electron acceptors for growth and produces no acid, gas, and sulfide in triple sugar iron agar slants. CG-1 also expresses a variety of lipids, most notably cyclopropyl C19 (cycC19), or lactobacillic acid, characteristic of organisms belonging to the

  5. Methane production from formate, acetate and H2/CO2; focusing on kinetics and microbial characterization.

    PubMed

    Pan, Xiaofang; Angelidaki, Irini; Alvarado-Morales, Merlin; Liu, Houguang; Liu, Yuhong; Huang, Xu; Zhu, Gefu

    2016-10-01

    For evaluating the methanogenesis from typical methanogenic precursors (formate, acetate and H2/CO2), CH4 production kinetics were investigated at 37±1°C in batch anaerobic digestion tests and stimulated by modified Gompertz model. The results showed that maximum methanation rate from formate, acetate and H2/CO2 were 19.58±0.49, 42.65±1.17 and 314.64±3.58NmL/gVS/d in digested manure system and 6.53±0.31, 132.04±3.96 and 640.16±19.92NmL/gVS/d in sewage sludge system during second generation incubation. Meanwhile the model could not fit well in granular sludge system, while the rate of formate methanation was faster than from H2/CO2 and acetate. Considering both the kinetic results and microbial assay we could conclude that H2/CO2 methanation was the fastest methanogenic step in digested manure and sewage sludge system with Methanomicrobiales as dominant methanogens, while granular sludge with Methanobacteriales as dominant methanogens contributed to the fastest formate methanation.

  6. Geomechanical Reservoir Characterization for Prediction of the Likelihood of Faulting Induced by CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Chiaramonte, L.; Zoback, M.; Friedmann, J.; Stamp, V.

    2006-12-01

    Geologic sequestration of CO2 has been proposed as a key technology for reducing greenhouse gas in the atmosphere. However, leakage of CO2 from any potential reservoir could seriously compromise the goal of long-term storage. Therefore understanding the likelihood of leakage is a key step toward the feasibility of this technology. Because it has long been known that fluid injection can lead to fault reactivation, assessing the potential of induced fault slip and leakage of CO2 from any potential storage reservoir is critical prior to injection of large quantities of CO2. We have developed a geomechanical model in advance of a proposed injection experiment at Teapot Dome, WY in order to study in detail the processes of a CO2 leak through predicted faults. Teapot Dome is an elongated asymmetrical, basement-cored anticline with a north-northeast axis. It is part of the Salt Creek structural trend, located in the southwestern edge of the Powder River Basin. The anticline is compartmentalized in a series of oblique-slip faults, generally oriented NE-SW, although varying in geometry, displacement, and complexity. In particular, the fault network referred to as S2 shows a greater complexity and a range of geometries and azimuths that enhances its potential for leakage. Furthermore its surface expression show alkali springs and hydrocarbon samples within the fault veins and gouge. The S2 fault intersects the oil-bearing 2nd Wall Creek around 650m, which is close in terms of temperature and pressure to conditions of supercritical CO2 phase injection and oil miscibility. We developed a preliminary geomechanical model of the deeper Tensleep Fm. previously, utilizing observations of wellbore breakouts, drilling induced fractures, leak-off or mini-frac tests and other available geophysical data. We used this information to evaluate the potential for injection to induce slip on the S1 fault, approximately 2 km south of the present study area. These results are compared and

  7. Seismic dynamic monitoring in CO2 flooding based on characterization of frequency-dependent velocity factor

    NASA Astrophysics Data System (ADS)

    Zhang, Jun-Hua; Li, Jun; Xiao, Wen; Tan, Ming-You; Zhang, Yun-Ying; Cui, Shi-Ling; Qu, Zhi-Peng

    2016-06-01

    The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reservoir conditions it is thus feasible to extract the frequency-dependent velocity factor with the aim of monitoring changes in the reservoir both before and after CO2 injection. In the paper, we derive a quantitative expression for the frequency-dependent factor based on the Robinson seismic convolution model. In addition, an inversion equation with a frequency-dependent velocity factor is constructed, and a procedure is implemented using the following four processing steps: decomposition of the spectrum by generalized S transform, wavelet extraction of cross-well seismic traces, spectrum equalization processing, and an extraction method for frequency-dependent velocity factor based on the damped least-square algorithm. An attenuation layered model is then established based on changes in the Q value of the viscoelastic medium, and spectra of migration profiles from forward modeling are obtained and analyzed. Frequency-dependent factors are extracted and compared, and the effectiveness of the method is then verified using a synthetic data. The frequency-dependent velocity factor is finally applied to target processing and oil displacement monitoring based on real seismic data obtained before and after CO2 injection in the G89 well block within Shengli oilfield. Profiles and slices of the frequency-dependent factor determine its ability to indicate differences in CO2 flooding, and the predicting results are highly consistent with those of practical investigations within the well block.

  8. Controlled Synthesis, Characterization, and Photocatalytic Application of Co2TiO4 Nanoparticles

    NASA Astrophysics Data System (ADS)

    Ramezani, Majid; Hosseinpour-Mashkani, S. Mostafa

    2017-02-01

    In the current study, an attempt is made to synthesize Co2TiO4 nanoparticles through the simple two-step sol-gel method with the aid of titanium(IV) isopropoxide and cobalt(II) acetate tetrahydrate as starting reagents in the presence of ethanol as a solvent. Additionally, the effects of sodium hydroxide and oxalic acid as the pH controller agents on the morphology and particle size of the products were investigated. Furthermore, effects of several natural and chemical surfactants such as starch, lactose, glucose, oleyl amine, and sodium dodecyl sulfate (SDS) on the morphology and particle size of final products were investigated. Based on the scanning electron microscopy (SEM) results, the above-mentioned parameters have a direct effect on the morphology and particle size of Co2TiO4 nanoparticles. The x-ray diffraction (XRD) results showed that pure cubic cobalt titanium oxide nanoparticles were obtained by this method after heat treatment at 600 and 900°C. Moreover, in the presence of Co2TiO4 nanoparticles as photocatalyst, the percentage of methyl orange (MO) degradation was about 100% after 40 min of irradiation of ultraviolet (UV) light.

  9. Geological characterization of Italian reservoirs and numerical 3D modelling of CO2 storage scenarios into saline aquifers

    NASA Astrophysics Data System (ADS)

    Beretta, S.; Moia, F.; Guandalini, R.; Cappelletti, F.

    2012-04-01

    The research activities carried out by the Environment and Sustainable Development Department of RSE S.p.A. aim to evaluate the feasibility of CO2 geological sequestration in Italy, with particular reference to the storage into saline aquifers. The identification and geological characterization of the Italian potential storage sites, together with the study of the temporal and spatial evolution of the CO2 plume within the caprock-reservoir system, are performed using different modelling tools available in the Integrated Analysis Modelling System (SIAM) entirely powered in RSE. The numerical modelling approach is the only one that allows to investigate the behaviour of the injected CO2 regarding the fluid dynamic, geochemical and geomechanical aspects and effects due to its spread, in order to verify the safety of the process. The SIAM tools allow: - Selection of potential Italian storage sites through geological and geophysical data collected in the GIS-CO2 web database; - Characterization of caprock and aquifer parameters, seismic risk and environmental link for the selected site; - Creation of the 3D simulation model for the selected domain, using the modeller METHODRdS powered by RSE and the mesh generator GMSH; - Simulation of the injection and the displacement of CO2: multiphase fluid 3D dynamics is based on the modified version of TOUGH2 model; - Evaluation of geochemical reaction effects; - Evaluation of geomechanic effects, using the coupled 3D CANT-SD finite elements code; - Detailed local analysis through the use of open source auxiliary tools, such as SHEMAT and FEHM. - 3D graphic analysis of the results. These numerical tools have been successfully used for simulating the injection and the spread of CO2 into several real Italian reservoirs and have allowed to achieve accurate results in terms of effective storage capacity and safety analysis. The 3D geological models represent the high geological complexity of the Italian subsoil, where reservoirs are

  10. Characterization of the Axial Jet Separator with a CO2/Helium Mixture: Toward GC-AMS Hyphenation.

    PubMed

    Salazar, G; Agrios, K; Eichler, R; Szidat, S

    2016-02-02

    Development of interfaces for sample introduction from high pressures is important for real-time online hyphenation of chromatographic and other separation devices with mass spectrometry (MS) or accelerator mass spectrometry (AMS). Momentum separators can reduce unwanted low-density gases and introduce the analyte into the vacuum. In this work, the axial jet separator, a new momentum interface, is characterized by theory and empirical optimization. The mathematical model describes the different axial penetration of the components of a jet-gas mixture and explains the empirical results for injections of CO2 in helium into MS and AMS instruments. We show that the performance of the new interface is sensitive to the nozzle size, showing good qualitative agreement with the mathematical model. Smaller nozzle sizes are more preferable due to their higher inflow capacity. The CO2 transmission efficiency of the interface into a MS instrument is ∼ 14% (CO2/helium separation factor of 2.7). The interface receives and delivers flows of ∼ 17.5 mL/min and ∼ 0.9 mL/min, respectively. For the interfaced AMS instrument, the ionization and overall efficiencies are 0.7-3% and 0.1-0.4%, respectively, for CO2 amounts of 4-0.6 μg C, which is only slightly lower compared to conventional systems using intermediate trapping. The ionization efficiency depends on to the carbon mass flow in the injected pulse and is suppressed at high CO2 flows. Relative to a conventional jet separator, the transmission efficiency of the axial jet separator is lower, but its performance is less sensitive to misalignments.

  11. Prototype Near-Field/GIS Model for Sequestered-CO2 Risk Characterization and Management

    SciTech Connect

    Bogen, K T; Homann, S G; Gouveia, F J; Neher, L A

    2006-02-10

    Detecting unmapped abandoned wells thus remains a major carbon sequestration (CS) technology gap. Many (>10{sup 5}) abandoned wells are thought to lie in potential sequestration sites. For such wells, risk analysis to date has focused on aggregate long-term future impacts of seepage at rates < or << {approx}1 g m{sup 2} d{sup -1} on storage goals as sequestered plumes encroach upon wells with assumed distributions of seal ineffectiveness (Oldenburg and Unger, 2003; Saripali et al. 2003; Celia, 2005). However, unmapped abandoned wells include an unknown number without any effective seal at all, venting through which may dominate CO{sub 2}-loss scenarios. A model of such a well is Crystal Geyser (CG), a prospective oil well abandoned in the 1930s with no barrier installed after it encountered a natural CO{sub 2} reservoir rather than oil (Baer and Rigby, 1978; Rinehart, 1980). CG demonstrates how an unimpeded conduit to the surface now regularly vents from 10{sup 3} to >10{sup 4} kg of CO{sub 2} gas to the terrestrial surface (Figure 1). Unique field data recently gathered from Crystal Geyser (CG) in Utah (Gouveia et al. 2005) confirm that, although resulting surface CO{sub 2} concentrations resulting from CG-like eruptions would likely be safe in general, they could accumulate to pose lethal hazards under relatively rare meteorological and topographic (MT) conditions. This source of foreseeable risk needs to be managed if carbon sequestration is to be publicly accepted. To address this concern, we used CG field data to estimate the source term for a prototype model that identifies zones at relatively highly elevated risk for sequestered-CO{sub 2} casualties. Such a model could be applied both to design and comply with future regulatory requirements to survey high-risk zones in each proposed sequestration site for improperly sealed wells.

  12. Silurian "Clinton" Sandstone Reservoir Characterization for Evaluation of CO2-EOR Potential in the East Canton Oil Field, Ohio

    SciTech Connect

    Ronald Riley; John Wicks; Christopher Perry

    2009-12-30

    The purpose of this study was to evaluate the efficacy of using CO2-enhanced oil recovery (EOR) in the East Canton oil field (ECOF). Discovered in 1947, the ECOF in northeastern Ohio has produced approximately 95 million barrels (MMbbl) of oil from the Silurian 'Clinton' sandstone. The original oil-in-place (OOIP) for this field was approximately 1.5 billion bbl and this study estimates by modeling known reservoir parameters, that between 76 and 279 MMbbl of additional oil could be produced through secondary recovery in this field, depending on the fluid and formation response to CO2 injection. A CO2 cyclic test ('Huff-n-Puff') was conducted on a well in Stark County to test the injectivity in a 'Clinton'-producing oil well in the ECOF and estimate the dispersion or potential breakthrough of the CO2 to surrounding wells. Eighty-one tons of CO2 (1.39 MMCF) were injected over a 20-hour period, after which the well was shut in for a 32-day 'soak' period before production was resumed. Results demonstrated injection rates of 1.67 MMCF of gas per day, which was much higher than anticipated and no CO2 was detected in gas samples taken from eight immediately offsetting observation wells. All data collected during this test was analyzed, interpreted, and incorporated into the reservoir characterization study and used to develop the geologic model. The geologic model was used as input into a reservoir simulation performed by Fekete Associates, Inc., to estimate the behavior of reservoir fluids when large quantities of CO2 are injected into the 'Clinton' sandstone. Results strongly suggest that the majority of the injected CO2 entered the matrix porosity of the reservoir pay zones, where it diffused into the oil. Evidence includes: (A) the volume of injected CO2 greatly exceeded the estimated capacity of the hydraulic fracture and natural fractures; (B) there was a gradual injection and pressure rate build-up during the test; (C) there was a subsequent, gradual flashout of

  13. Silurian "Clinton" Sandstone Reservoir Characterization for Evaluation of CO2-EOR Potential in the East Canton Oil Field, Ohio

    SciTech Connect

    Riley, Ronald; Wicks, John; Perry, Christopher

    2009-12-30

    The purpose of this study was to evaluate the efficacy of using CO2-enhanced oil recovery (EOR) in the East Canton oil field (ECOF). Discovered in 1947, the ECOF in northeastern Ohio has produced approximately 95 million barrels (MMbbl) of oil from the Silurian “Clinton” sandstone. The original oil-in-place (OOIP) for this field was approximately 1.5 billion bbl and this study estimates by modeling known reservoir parameters, that between 76 and 279 MMbbl of additional oil could be produced through secondary recovery in this field, depending on the fluid and formation response to CO2 injection. A CO2 cyclic test (“Huff-n-Puff”) was conducted on a well in Stark County to test the injectivity in a “Clinton”-producing oil well in the ECOF and estimate the dispersion or potential breakthrough of the CO2 to surrounding wells. Eighty-one tons of CO2 (1.39 MMCF) were injected over a 20-hour period, after which the well was shut in for a 32-day “soak” period before production was resumed. Results demonstrated injection rates of 1.67 MMCF of gas per day, which was much higher than anticipated and no CO2 was detected in gas samples taken from eight immediately offsetting observation wells. All data collected during this test was analyzed, interpreted, and incorporated into the reservoir characterization study and used to develop the geologic model. The geologic model was used as input into a reservoir simulation performed by Fekete Associates, Inc., to estimate the behavior of reservoir fluids when large quantities of CO2 are injected into the “Clinton” sandstone. Results strongly suggest that the majority of the injected CO2 entered the matrix porosity of the reservoir pay zones, where it diffused into the oil. Evidence includes: (A) the volume of injected CO2 greatly exceeded the estimated capacity of the hydraulic fracture and natural fractures; (B) there was a gradual injection and pressure rate build-up during the test; (C) there was a subsequent

  14. Preparation and characterization of Co2TiO4 and doped Co2- x M x TiO4 (M = Zn2+, Ni2+)-coated mica composite pigments

    NASA Astrophysics Data System (ADS)

    Zhang, Shuting; Ye, Mingquan; Han, Aijun; Liu, Chunlan

    2016-07-01

    Green composite pearlescent pigments were prepared by coating Co2TiO4 and doped Co2- x M x TiO4 nanoparticles on mica. The effects of calcination temperature, Ti/Co mole ratio and doped ions Ni2+ and Zn2+ on the crystal structure of mica/Co2- x M x TiO4 were studied. Scanning electron microscopy, atomic force microscopy and X-ray diffraction (XRD) technique were employed to characterize the morphology and crystal features of the composite particles. TG-DSC analysis and XRD patterns analysis showed that the appropriate calcination temperature for mica/Co2TiO4 pigments was about 1000 °C. UV-Vis spectroscopy and CIE L* a* b* parameters revealed that the composite pigments were yellow-green, and the color and colorimetric parameters changed with the particle size of mica, types of coated pigments and coating amount of pigments on mica. Moreover, the lightness L* of mica/Co2- x M x TiO4 pigments was larger than that of undoped mica/Co2TiO4, and it increased with increasing doped Zn2+ and Ni2+ content.

  15. The Synthesis and Characterization of Multifunctional Titania-based Materials for the Photo/Thermal Catalytic Reduction of CO2

    NASA Astrophysics Data System (ADS)

    Schwartzenberg, Kevin

    The work presented in this dissertation is aimed at improving our understanding of the fundamental processes required for the photocatalytic reduction of CO2. A QCM reactor system for measuring CO2 adsorption under a range of conditions was designed, constructed, and characterized. Measurements on catalyst films revealed sufficient sensitivity to detect CO2 adsorption on the order of 0.1 molecules/nm2. Adsorption experiments were repeatable across multiple measurements for the same film. However, variation across multiple films prepared using the same mass of catalyst highlights the large contribution of surface roughness to frequency response and the importance of uniform, reproducible film preparation. The design of a multifunctional photo/thermal catalyst was explored through the concept of MnOx-TiO2 composites with thermally generated oxygen vacancies as the active sites for CO2 activation. MnOx-TiO 2 were prepared by incipient wetness impregnation of titania supports with one of two Mn precursors, and were characterized and screened for catalytic activity. The results were compared with predictions from theoretical modeling studies. Through TPR, UV-vis spectroscopy, and XANES, it was observed that a Mn(NO 3)2•4H2O precursor led to bulk-like domains of MnOx whereas a Mn(CH3COO)2•4H2O precursor led to a dispersed surface oxide. This precursor effect was less pronounced on rutile than on anatase support. As predicted by theory, the MnOx-TiO 2 exhibited the reversible generation of oxygen vacancies at mild temperatures (< 300°C) and a red shift in the band gap for anatase-supported composites. A similar red shift was not observed for rutile-supported materials. In screening reactions, however, neither CO nor other products were detected by GC. In-situ FTIR experiments also failed to show evidence of nonvolatile CO2 reduction products. However, several carbonate, bicarbonate, and carboxylate species were observed, confirming the interaction of CO 2 with oxygen

  16. Synthesis and characterization of NiCo2O4 nanoplates as efficient electrode materials for electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Kim, Taehyun; Ramadoss, Ananthakumar; Saravanakumar, Balasubramaniam; Veerasubramani, Ganesh Kumar; Kim, Sang Jae

    2016-05-01

    In the present work, NiCo2O4 nanoplates were prepared by a facile, low temperature, hydrothermal method, followed by thermal annealing and used supercapacitor applications. The physico-chemical characterization of as-prepared materials were investigated by means of X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). The electrochemical measurements demonstrate that the NiCo2O4 nanoplates electrode (NC-5) exhibits a high specific capacitance of 332 F g-1 at a scan rate of 5 mV s-1 and also retained about 86% of the initial specific capacitance value even after 2000 cycles at a current density of 2.5 A g-1. These results suggest that the fabricated electrode material has huge potential as a novel electrode material for electrochemical capacitors.

  17. Characterization of deep saline aquifers for CO2 storage capacity assessment, Bécancour area, Québec, Canada

    NASA Astrophysics Data System (ADS)

    TRAN NGOC, T.; Konstantinovskaya, E. A.; Lefebvre, R.; Malo, M.

    2011-12-01

    The Cambrian-Ordovician St. Lawrence Lowlands basin of southern Québec has been assessed the most prospective for CO2 storage potential according to geological and practical criteria. Such a demonstration requires the assessment of numerous aspects: storing, injectivity, containment and adequate long-term monitoring. To do so, the characterisation stage of potential sites has to be comprehensive. We provide a case study of the CO2 storage capacity assessment in the deep saline aquifers of the Bécancour region (between Montréal and Québec City) through characterizing in term of hydrogeology and rock petrophysics. The analysed data include stratigraphy and lithology, drill stem tests, hydraulic well tests, well logging, fluid sampling and core analyses. The saline aquifers of the Bécancour region are found at depths between 800 and 2400 m in sandstones of the Potsdam Gp., dolomites of the Beekmantown Gp, and limestones of the Trenton Gp. The caprock consists of at least 800 m of siltstone and shale. The reservoir units are compartmentalized at depth into two distinct blocks by the Yamaska regional normal fault trending SW-NE. Hydrostatic pressure measurements from different intervals and locations show different pressure gradients ΔP with the average value of 12.17 kPa/m, varying from 10.78 kPa/m in the northeastern part of the region and to 15.60 kPa/m in its southwestern part. We observed also different in situ artesian rates of brine-producing boreholes: Q=0, 0< Q <10 and Q=13 l/min which is correlated to ΔP magnitudes. This indicates that the site reservoir is partially overpressurized and non-homogeneous at the regional scale. Permeability anisotropy from core analyses (k_h/k_v = O(10^2)) is indicative of dominant horizontal hydraulic connectivity. Average salinity profiles differing from S=109 g/l to 242 g/l in separate reservoir units confirms this lateral connectivity preponderance and a vertical discontinuity between the aquifers. An average

  18. The preparation and electrochemical characterization of urchin-like NiCo2O4 nanostructures

    NASA Astrophysics Data System (ADS)

    Dong, J. Y.; Zhang, X. T.

    2015-03-01

    The urchin-like NiCo2O4 nanostructures were synthesized by a mild hydrothermal method. A possible growth mechanism is proposed based on the morphology evolution process upon reaction time. The effect of the concentration of metal salt on the electrochemical performance was investigated. The high electrochemical performance was achieved by optimizing the concentration. The corresponding specific capacitance is as high as 1484.1 F g-1 at the current density of 1 A g-1. Furthermore, the capacitance retains 90.1% even after more than 2000 cycles. The resulting high performance is due to the unique three-dimensional structure constructed by nanorings and nanowires, which increases the amount of electroactive sites and facilitates the electrolyte penetration and electron transfer.

  19. Strain and temperature characterization of LPGs written by CO2 laser in pure silica LMA photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Chaves, Roberta Cardoso; Pohl, Alexandre de Almeida Prado; Abe, Ilda; Sebem, Renan; Paterno, Aleksander

    2015-09-01

    This paper reports on the writing of long period gratings (LPGs) in a six-ring pure silica solid core, and large mode area photonic crystal fiber (fiber core diameter ρ = 10.1 μm) using a CO2 laser system, and the characterization of their strain and temperature sensitivities. Temperature and strain sensitivities in the order of -19.6 pm/°C and -88 pm/μɛ, respectively, were obtained, which were comparable or surpassed values of the similar photonic crystal fiber (PCF)-based LPG or sensor configurations found in the literature.

  20. Exploring the effects of data quality, data worth, and redundancy of CO2 gas pressure and saturation data on reservoir characterization through PEST Inversion

    SciTech Connect

    Fang, Zhufeng; Hou, Zhangshuan; Lin, Guang; Engel, David W.; Fang, Yilin; Eslinger, Paul W.

    2014-04-01

    This study examined the impacts of reservoir properties on CO2 migration after subsurface injection and evaluated the possibility of characterizing reservoir properties using CO2 monitoring data such as saturation distribution. The injection reservoir was assumed to be located 1400-1500 m below the ground surface such that CO2 remained in the supercritical state. The reservoir was assumed to contain layers with alternating conductive and resistive properties, which is analogous to actual geological formations such as the Mount Simon Sandstone unit. The CO2 injection simulation used a cylindrical grid setting in which the injection well was situated at the center of the domain, which extended up to 8000 m from the injection well. The CO2 migration was simulated using the PNNL-developed simulator STOMP-CO2e (the water-salt-CO2 module). We adopted a nonlinear parameter estimation and optimization modeling software package, PEST, for automated reservoir parameter estimation. We explored the effects of data quality, data worth, and data redundancy on the detectability of reservoir parameters using CO2 saturation monitoring data, by comparing PEST inversion results using data with different levels of noises, various numbers of monitoring wells and locations, and different data collection spacing and temporal sampling intervals. This study yielded insight into the use of CO2 saturation monitoring data for reservoir characterization and how to design the monitoring system to optimize data worth and reduce data redundancy.

  1. Characterization of seepage surfaces from Space-borne radar interferometry stacking techniques, Southern Dead Sea area, Jordan

    NASA Astrophysics Data System (ADS)

    Tessari, Giulia; Closson, Damien; Abou Karaki, Najib; Atzori, Simone; Fiaschi, Simone; Floris, Mario; Pasquali, Paolo; Riccardi, Paolo

    2014-05-01

    The Dead Sea is a terminal lake located in a pull-apart basin of the Dead Sea Transform fault zone. It is the lowest emerged place on Earth at about -428 m bsl. Since the 1960s, the over-pumping of its tributaries leads to a decrease in the water level. Eventually, it became more pronounced decades after decades. In 2014, it is more than 1m/year. The overall drop is around 33 m. With salinity ten times greater than the ocean water one, the lake body and its underground lateral extensions act as a high density layer over which the fresh ground waters are in hydrostatic equilibrium. The slope of the interface between saline and fresh waters is ten times shallower than normally expected near the ocean. According to a number of wells along the Jordanian Dead Sea coast, the water table level does not drop at the same speed than the Dead Sea. An increasingly important gradient is constantly being created along the coastal zone. In many places, the fresh ground waters move very rapidly towards the base level to compensate for the imbalance. This statement is supported by a body of observations: a) appearance of vegetation (Tamarisk) in arid areas (precipitation: 50 to 70 mm/year) dominated by salt deposits such as the Lisan peninsula; b) presence of submarine circular collapses visible along the coast. Their diameters decreasing with distance from the shore line; c) appearances of springs and recurring landslides along the coast. With the exception of the submarine features, all these elements are located in the land strip that emerged progressively from the 1960s, 33 m in elevation, ranging from a few decameters up to several kilometers wide. In many places, the surface is characterized by superficial seepages causing subtle to very pronounced subsidence, and sinkholes. In this contribution, we show that advanced differential radar interferometry techniques applied to ERS, ENVISAT and COSMO-SkyMed images stacks are able to underscore the most affected places. The mapping

  2. Characterization of OMEGA/MEx CO2 non-LTE limb observations on the dayside of Mars

    NASA Astrophysics Data System (ADS)

    Piccialli, A.; Drossart, P.; Lopez-Valverde, M. A.; Altieri, F.; Määttänen, A.; Gondet, B.; Witasse, O.; Bibring, J. P.

    2012-09-01

    The upper atmosphere of a terrestrial planet is a region difficult to sound, both by in-situ and remote sounding [1]. This atmospheric region is characterized by non-local thermodynamic equilibrium (non-LTE) that occurs when collisions between atmospheric species are not enough efficient in transferring energy. The CO2 non-LTE emission at 4.3 μm originates in the upper layers of the atmosphere and is a feature common to the three terrestrial planets with an atmosphere (Venus, Earth, and Mars). It provides a useful tool to gain insight into the atmospheric processes at these altitudes [2]. Non-LTE fluorescent emissions were first observed in the Earth's upper atmosphere in CO2 bands at 15 and 4.3 μm [3] and were later observed on several planets in different spectral bands. Ground-based observations of CO2 laser bands at 10 μm in the atmospheres of Venus and Mars [4] were interpreted as non-LTE emissions by several atmospheric models developed in the 1980s [5]. On Jupiter, Saturn and Titan non-LTE emissions were identified in the CH4 band at 3.3 μm [6]. More recently, CO2 non-LTE emission at 4.3 μm was detected in the upper atmosphere of Mars and Venus by the PFS (Planetary Fourier Spectrometer) and OMEGA (Visible and Infrared Mapping Spectrometer) experiments on board the European spacecraft Mars Express [7, 8, 9] and by VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) on board the European Venus Express [10]. These observations led to the development of a more comprehensive non-LTE model for the upper atmosphere [9, 11]. According to these models, during daytime the solar radiation in several near-IR bands from 1 to 5 μm produce enhanced state populations of many CO2 vibrational levels which cascade down to lower states emitting photons in diverse 4.3 μm bands. These emissions produce what is observed.

  3. Synthesis, characterization and evaluation of CO-oxidation catalysts for high repetition rate CO2 TEA lasers

    NASA Technical Reports Server (NTRS)

    Moser, Thomas P.

    1990-01-01

    An extremely active class of noble metal catalysts supported on titania was developed and fabricated at Hughes for the recombination of oxygen (O2) and carbon monoxide (CO) in closed-cycle CO2 TEA lasers. The incipient wetness technique was used to impregnate titania and alumina pellets with precious metals including platinum and palladium. In particular, the addition of cerium (used as an oxygen storage promoter) produced an extremely active Pt/Ce/TiO2 catalyst. By comparison, the complementary Pt/Ce/ gamma-Al2O3 catalyst was considerably less active. In general, chloride-free catalyst precursors proved critical in obtaining an active catalyst while also providing uniform metal distributions throughout the support structure. Detailed characterization of the Pt/Ce/TiO2 catalyst demonstrated uniform dendritic crystal growth of the metals throughout the support. Electron spectroscopy for Chemical Analysis (ESCA) analysis was used to characterize the oxidation states of Pt, Ce and Ti. The performance of the catalysts was evaluated with an integral flow reactor system incorporating real time analysis of O2 and CO. With this system, the transient and steady-state behavior of the catalysts were evaluated. The kinetic evaluation was complemented by tests in a compact, closed-cycle Hughes CO2 TEA laser operating at a pulse repetition rate of 100 Hz with a catalyst temperature of 75 to 95 C. The Pt/Ce/TiO2 catalyst was compatible with a C(13)O(16)2 gas fill.

  4. Monitoring of Potential Seepage Through Surface Sediments in the Sleipner Carbon Capture and Storage Area

    NASA Astrophysics Data System (ADS)

    James, R. H.; Lichtschlag, A.; Cevatoglu, M.; Reigstad, L.; Connelly, D.; Bull, J. M.

    2013-12-01

    Subseafloor Carbon Capture and Storage (CCS) has been recognized as critical technology for reducing the release of anthropogenic CO2 emissions to the atmosphere. However, the potential pathways of CO2 movement in the sedimentary overburden as well as the impact of any CO2 seepage from a storage site on the marine environment are poorly understood. As part of the ECO2 project, we have conducted a multidisciplinary survey of the area around Sleipner, which is one of the longest operated subseafloor CCS sites. Our aims were to: (1) Search for tracers of leakage of formation fluids or any other potential precursors of CO2 seepage, in the vicinity of the subseafloor CO2 plume. (2) Assess the potential for mobilization of toxic metals by CO2. (3) Characterize the environment in the vicinity of the Sleipner storage site. Potential pathways of seepage from the storage site were determined by the AUV AUTOSUB, that was equipped with a variety of instrumentation including sidescan sonar and an EM2000 multibeam systems, as well as a CHIRP profiler capable of inspecting the architecture of the sedimentary overburden. To detect geochemical indicators of leakage and their potential impact on the seafloor environment, the composition of fluids and gases were determined in the upper part of the sediment overburden (up to 3.8 m below seafloor), which was recovered by vibrocoring. The microbial activity in these sediments was also determined, by measuring the RNA content of selected cores. In this presentation we will compare the results that we have obtained from the area above the CO2 plume with results from an area ~20 km the north of the Sleipner platform (Hugin fracture). The Hugin fracture is several km long, and pore fluids from sediments recovered from the fracture have a distinctively different composition, with depletion of sulphate and chloride and increase of sulphide, dissolved inorganic carbon and total alkalinity. Assessing the natural variation in the sedimentary

  5. An integrated petrophysical-geophysical approach for the characterization of a potential caprock-reservoir system for CO2 storage.

    NASA Astrophysics Data System (ADS)

    Fais, Silvana; Ligas, Paola; Cuccuru, Francesco; Casula, Giuseppe; Giovanna Bianchi, Maria; Maggio, Enrico; Plaisant, Alberto; Pettinau, Alberto

    2016-04-01

    The selection of a CO2 geologic storage site requires the choice of a study site suitable for the characterization in order to create a robust experimental database especially regarding the spatial petrophysical heterogeneities and elasto-mechanical properties of the rocks that make up a potential caprock-reservoir system. In our study the petrophysical and elasto-mechanical characterization began in a previously well drilled area in the northern part of the Sulcis coal basin (Nuraxi Figus area - SW Sardinia - Italy) where crucial geologic data were recovered from high-quality samples from stratigraphic wells and from mining galleries. The basin represents one of the most important Italian carbon reserves characterized by a great mining potential. In the study area, the Middle Eocene - Lower Oligocene Cixerri Fm. made up of terrigeneous continental rocks and the Upper Thanetian - Lower Ypresian Miliolitico Carbonate Complex in the Sulcis coal basin have been identified respectively as potential caprock and reservoir for CO2 storage. Petrophysical and geophysical investigations were carried out by a great number of laboratory tests on the core samples and in situ measurements on a mining gallery in order to characterize the potential caprock-reservoir system and to substantially reduce geologic uncertainty in the storage site characterization and in the geological and numerical modelling for the evaluation of CO2 storage capacity. In order to better define the spatial distribution of the petrophysical heterogeneity, the seismic responses from the caprock-reservoir system formations were also analysed and correlated with the petrophysical and elasto-mechanical properties In a second step of this work, we also analysed the tectonic stability of the study area by the integrated application of remote-sensing monitoring spatial geodetic techniques. In particular, the global positioning system (GPS) and interferometric synthetic aperture radar (inSAR) were considered

  6. Performance characterization and ground testing of an airborne CO2 differential absorption LIDAR system

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Fox, Marsha J.; Bousek, Ronald R.; Dowling, James A.; Richter, Dale A.; Kelly, Brian T.

    1998-01-01

    The Phillips Laboratory Remote Optical Sensors (ROS) program is developing the Laser Airborne Remote Sensing (LARS) system for chemical detection using the differential absorption lidar (DIAL) technique. The system is based upon a high-power CO(subscript 2) laser which can use either the standard (superscript 12)C(superscript 16)O(subscript 2) or the (superscript 13)C(superscript 16)O(subscript 2) carbon dioxide isotopes as the lasing medium, and has output energies in excess of 4 J on the stronger laser transitions. The laser, transmitter optics, receiver telescope and optics, and monitoring equipment are mounted on a flight-qualified optical breadboard designed to mount in the Argus C-135E optical testbed aircraft operated by Phillips Laboratory. The LARS system is being prepared for initial flight experiments at Kirtland AFB, NM, in August 1997, and for chemical detection flight experiments at the Idaho National Engineering Laboratory (INEL) in September 1997. This paper briefly describes the system characterization, and presents some results from the pre- flight ground testing.

  7. Teapot Dome: Site Characterization of a CO2- Enhanced Oil Recovery Site in Eastern Wyoming

    SciTech Connect

    Friedmann, S J; Stamp, V

    2005-11-01

    Naval Petroleum Reserve No. 3 (NPR-3), better known as the Teapot Dome oil field, is the last U.S. federally-owned and -operated oil field. This provides a unique opportunity for experiments to provide scientific and technical insight into CO{sub 2}-enhanced oil recovery (EOR) and other topics involving subsurface fluid behavior. Towards that end, a combination of federal, academic, and industrial support has produced outstanding characterizations of important oil- and brine-bearing reservoirs there. This effort provides an unparalleled opportunity for industry and others to use the site. Data sets include geological, geophysical, geochemical, geomechanical, and operational data over a wide range of geological boundary conditions. Importantly, these data, many in digital form, are available in the public domain due to NPR-3's federal status. Many institutions are already using portions of the Teapot Dome data set as the basis for a variety of geoscience, modeling, and other research efforts. Fifteen units, 9 oil-bearing and 6 brine-bearing, have been studied to varying degrees. Over 1200 wells in the field are active or accessible, and over 400 of these penetrate 11 formations located below the depth that corresponds to the supercritical point for CO{sub 2}. Studies include siliciclastic and carbonate reservoirs; shale, carbonate, and anhydrite cap rocks; fractured and unfractured units; and over-pressured and under-pressured zones. Geophysical data include 3D seismic and vertical seismic profiles. Reservoir data include stratigraphic, sedimentological, petrologic, petrographic, porosity, and permeability data. These have served as the basis for preliminary 3D flow simulations. Geomechanical data include fractures (natural and drilling induced), in-situ stress determination, pressure, and production history. Geochemical data include soil gas, noble gas, organic, and other measures. The conditions of these reservoirs directly or indirectly represent many reservoirs

  8. Superposition well-test method for reservoir characterization and pressure management during CO2 injection

    NASA Astrophysics Data System (ADS)

    White, J. A.

    2014-12-01

    As a significant fraction of a carbon storage project's budget is devoted to site characterization and monitoring, there has been an intense drive in recent years to both lower cost and improve the quality of data obtained. Two data streams that are cheap and always available are pressure and flow rate measurements from the injection well. Falloff testing, in which the well is shut-in for some period of time and the pressure decline curve measured, is often used to probe the storage zone and look for indications of hydraulic barriers, fracture-dominated flow, and other reservoir characteristics. These tests can be used to monitor many hydromechanical processes of interest, including hydraulic fracturing and fault reactivation. Unfortunately, the length of the shut-in period controls how far away from the injector information may be obtained. For operational reasons these tests are typically kept short and infrequent, limiting their usefulness. In this work, we present a new analysis method in which ongoing injection data is used to reconstruct an equivalent falloff test, without shutting in the well. The entire history of injection may therefore be used as a stand in for a very long test. The method relies upon a simple superposition principle to transform a multi-rate injection sequence into an equivalent single-rate process. We demonstrate the effectiveness of the method using injection data from the Snøhvit storage project. We also explore its utility in an active pressure management scenario. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  9. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Wier, Don R. Chimanhusky, John S.; Czirr, Kirk L.; Hallenbeck, Larry; Gerard, Matthew G.; Dollens, Kim B.; Owen, Rex; Gaddis, Maurice; Moshell, M.K.

    2002-11-18

    The purpose of this project was to economically design an optimum carbon dioxide (CO2) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO2 horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields.

  10. Abstraction of Drift Seepage

    SciTech Connect

    J.T. Birkholzer

    2004-11-01

    This model report documents the abstraction of drift seepage, conducted to provide seepage-relevant parameters and their probability distributions for use in Total System Performance Assessment for License Application (TSPA-LA). Drift seepage refers to the flow of liquid water into waste emplacement drifts. Water that seeps into drifts may contact waste packages and potentially mobilize radionuclides, and may result in advective transport of radionuclides through breached waste packages [''Risk Information to Support Prioritization of Performance Assessment Models'' (BSC 2003 [DIRS 168796], Section 3.3.2)]. The unsaturated rock layers overlying and hosting the repository form a natural barrier that reduces the amount of water entering emplacement drifts by natural subsurface processes. For example, drift seepage is limited by the capillary barrier forming at the drift crown, which decreases or even eliminates water flow from the unsaturated fractured rock into the drift. During the first few hundred years after waste emplacement, when above-boiling rock temperatures will develop as a result of heat generated by the decay of the radioactive waste, vaporization of percolation water is an additional factor limiting seepage. Estimating the effectiveness of these natural barrier capabilities and predicting the amount of seepage into drifts is an important aspect of assessing the performance of the repository. The TSPA-LA therefore includes a seepage component that calculates the amount of seepage into drifts [''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504], Section 6.3.3.1)]. The TSPA-LA calculation is performed with a probabilistic approach that accounts for the spatial and temporal variability and inherent uncertainty of seepage-relevant properties and processes. Results are used for subsequent TSPA-LA components that may handle, for example, waste package corrosion or radionuclide transport.

  11. Groundwater-Seepage Meter

    NASA Technical Reports Server (NTRS)

    Walthall, Harry G.; Reay, William G.

    1993-01-01

    Instrument measures seepage of groundwater into inland or coastal body of water. Positioned at depth as great as 40 meters, and measures flow at low rate and low pressure differential. Auxiliary pressure meter provides data for correlation of flow of groundwater with tides and sea states. Seepage meter operates independently for several weeks. Its sampling rate adjusted to suit hydrologic conditions; to measure more frequently when conditions changing rapidly. Used in water-quality management and for biological and geological research. Potential industrial uses include measurement of seepage of caustic and corrosive liquids.

  12. Raman spectroscopic characterization of gas mixtures. II. Quantitative composition and pressure determination of the CO2-CH4 system

    USGS Publications Warehouse

    Seitz, J.C.; Pasteris, J.D.; Chou, I.-Ming

    1996-01-01

    Raman spectral parameters were determined for the v1 band of CH4 and the v1 and 2v2 bands (Fermi diad) of CO2 in pure CO2 and CO2-CH4 mixtures at pressures up to 700 bars and room temperature. Peak position, area, height, and width were investigated as functions of pressure and composition. The peak positions of the CH4 and CO2 bands shift to lower relative wavenumbers as fluid pressure is increased. The peak position of the lower-wavenumber member of the Fermi diad for CO2 is sensitive to fluid composition, whereas the peak positions of the CH4 band and the upper Fermi diad member for CO2 are relatively insensitive in the CO2-CH4 system. The magnitude of the shifts in each of the three peak positions (as a function of pressure) is sufficient to be useful as a monitor of fluid pressure. The relative molar proportions in a CO2-CH4 mixture may be determined from the peak areas: the ratio of the peak areas of the CH4 band and the CO2 upper Fermi diad member is very sensitive to composition, whereas above about 100 bars, it is insensitive to pressure. Likewise, the peak height ratio is very sensitive to composition but also to fluid pressure. The individual peak widths of CO2 and CH4, as well as the ratios of the widths of the CH4 peak to the CO2 peaks are a sensitive function of pressure and, to a lesser extent, composition. Thus, upon determination of fluid composition, the peak width ratios may be used as a monitor of fluid pressure. The application of these spectral parameters to a suite of natural CO2-CH4 inclusions has yielded internally-consistent, quantitative determinations of the fluid composition and density.

  13. Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

    USGS Publications Warehouse

    Majcher, Emily H.; Phelan, Daniel J.; Lorah, Michelle M.; McGinty, Angela L.

    2007-01-01

    Wetlands act as natural transition zones between ground water and surface water, characterized by the complex interdependency of hydrology, chemical and physical properties, and biotic effects. Although field and laboratory demonstrations have shown efficient natural attenuation processes in the non-seep wetland areas and stream bottom sediments of West Branch Canal Creek, chlorinated volatile organic compounds are present in a freshwater tidal creek at Aberdeen Proving Ground, Maryland. Volatile organic compound concentrations in surface water indicate that in some areas of the wetland, preferential flow paths or seeps allow transport of organic compounds from the contaminated sand aquifer to the overlying surface water without undergoing natural attenuation. From 2002 through 2004, the U.S. Geological Survey, in cooperation with the Environmental Conservation and Restoration Division of the U.S. Army Garrison, Aberdeen Proving Ground, characterized preferential ground-water seepage as part of an ongoing investigation of contaminant distribution and natural attenuation processes in wetlands at this site. Seep areas were discrete and spatially consistent during thermal infrared surveys in 2002, 2003, and 2004 throughout West Branch Canal Creek wetlands. In these seep areas, temperature measurements in shallow pore water and sediment more closely resembled those in ground water than those in nearby surface water. Generally, pore water in seep areas contaminated with chlorinated volatile organic compounds had lower methane and greater volatile organic compound concentrations than pore water in non-seep wetland sediments. The volatile organic compounds detected in shallow pore water in seeps were spatially similar to the dominant volatile organic compounds in the underlying Canal Creek aquifer, with both parent and anaerobic daughter compounds detected. Seep locations characterized as focused seeps contained the highest concentrations of chlorinated parent compounds

  14. Characterization of CO2-induced (?) bleaching phenomena in German red bed sediments by combined geochemical and evolved gas analysis

    NASA Astrophysics Data System (ADS)

    Hilse, Ulrike; Goepel, Andreas; Pudlo, Dieter; Heide, Klaus; Gaupp, Reinhard

    2010-05-01

    sulphates. DEGAS pattern show no obvious systematic differences between the varied coloured zones of this specimen. Sample A1 consists of totally bleached medium grained, lithoclast rich Rotliegend sandstone which was deposited on a flood plain with braided rivers and aeolian dunes. Subsamples of A1 are grouped into three zones - all are bleached, with colours ranging from white to dark grey. Grey and dark grey zones (A1-1 to A1-6, A1-15) are cemented by Ca-rich carbonates and contain microscopically identified bitumina. In contrast the pore space of white zones (A1-7 to A1-14) is filled by anhydrite. These mineralogical differences are also reflected in the bulk rock geochemistry. In comparison to grey rocks white subsamples are depleted in iron and related elements as well as in REEs. Moreover, correlations between rock colour and degassing behavior exist. White samples display typical degassing signatures of sulphates, whereas dark grey zones reveal minor sulphate content, but also the presence of an additional S-species (sulphide) and CO2 (carbonate). Similar features were obtained regarding the specification and abundance of hydrocarbon components. In all samples of A1 methane, ethane and carbonylsulphide were detected, with higher contents in the more whitish parts. In grey rocks an additional, long-chained hydrocarbon component occurs. The relevance of this species is not yet resolved and will be investigated further in more detail. Mass spectrometric gas analytical and related geochemical data confirm major differences in rock composition of Buntsandstein and Rotliegend samples, mainly caused by primary rock composition and by the involvement of variable fluid composition during burial diagenetic alteration. In this study DEGAS was applied for the first time to characterize sandstone geochemistry. Our results constrain that this method might be a complementary analytical tool appropriate for petrological sedimentary research.

  15. Geophysical and Hydrologic Studies of Lake Seepage Variability.

    PubMed

    Toran, Laura; Nyquist, Jonathan; Rosenberry, Donald; Gagliano, Michael; Mitchell, Natasha; Mikochik, James

    2015-01-01

    Variations in lake seepage were studied along a 130 m shoreline of Mirror Lake NH. Seepage was downward from the lake to groundwater; rates measured from 28 seepage meters varied from 0 to -282 cm/d. Causes of this variation were investigated using electrical resistivity surveys and lakebed sediment characterization. Two-dimensional (2D) resistivity surveys showed a transition in lakebed sediments from outwash to till that correlated with high- and low-seepage zones, respectively. However, the 2D survey was not able to predict smaller scale variations within these facies. In the outwash, fast seepage was associated with permeability variations in a thin (2 cm) layer of sediments at the top of the lakebed. In the till, where seepage was slower than that in the outwash, a three-dimensional resistivity survey mapped a point of high seepage associated with heterogeneity (lower resistivity and likely higher permeability). Points of focused flow across the sediment-water interface are difficult to detect and can transmit a large percentage of total exchange. Using a series of electrical resistivity geophysical methods in combination with hydrologic data to locate heterogeneities that affect seepage rates can help guide seepage meter placement. Improving our understanding of the causes and types of heterogeneity in lake seepage will provide better data for lake budgets and prediction of mass transfer of solutes or contaminants between lakes and groundwater.

  16. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales, Class III

    SciTech Connect

    Perri, Pasquale R.; Cooney, John; Fong, Bill; Julander, Dale; Marasigan, Aleks; Morea, Mike; Piceno, Deborah; Stone, Bill; Emanuele, Mark; Sheffield, Jon; Wells, Jeff; Westbrook, Bill; Karnes, Karl; Pearson, Matt; Heisler, Stuart

    2000-04-24

    The primary objective of this project was to conduct advanced reservoir characterization and modeling studies in the Antelope Shale of the Bureau Vista Hills Field. Work was subdivided into two phases or budget periods. The first phase of the project focused on a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work would then be used to evaluate how the reservoir would respond to enhanced oil recovery (EOR) processes such as of CO2 flooding. The second phase of the project would be to implement and evaluate a CO2 in the Buena Vista Hills Field. A successful project would demonstrate the economic viability and widespread applicability of CO2 flooding in siliceous shale reservoirs of the San Joaquin Valley.

  17. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Morea, Michael F.

    1999-11-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  18. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect

    Morea, Michael F.

    1999-11-08

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field.

  19. Characterization of Activated Carbons from Oil-Palm Shell by CO2 Activation with No Holding Carbonization Temperature

    PubMed Central

    Herawan, S. G.; Hadi, M. S.; Ayob, Md. R.; Putra, A.

    2013-01-01

    Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced. PMID:23737721

  20. Characterization of activated carbons from oil-palm shell by CO2 activation with no holding carbonization temperature.

    PubMed

    Herawan, S G; Hadi, M S; Ayob, Md R; Putra, A

    2013-01-01

    Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

  1. Encapsulation of CO2 into amorphous and crystalline α-cyclodextrin powders and the characterization of the complexes formed.

    PubMed

    Ho, Thao M; Howes, Tony; Bhandari, Bhesh R

    2015-11-15

    Carbon dioxide complexation was undertaken into solid matrices of amorphous and crystalline α-cyclodextrin (α-CD) powders, under various pressures (0.4-1.6 MPa) and time periods (4-96 h). The results show that the encapsulation capacity of crystalline α-CD was significantly lower than that of amorphous α-CD at low pressure and short time (0.4-0.8 MPa and 4-24 h), but was markedly enhanced with an increase of pressure and prolongation of encapsulation time. For each pressure level tested, the time required to reach a near equilibrium encapsulation capacity of the crystalline powder was around 48 h, which was much longer than that of the amorphous one, which only required about 8h. The inclusion complex formation of both types of α-CD powders was confirmed by the appearance of a CO2 peak on the FTIR and NMR spectra. Moreover, inclusion complexes were also characterized by DSC, TGA, SEM and X-ray analyses.

  2. Characterizing water and CO2 fluxes and their driving impact factors by using a hierarchical diagnostic geophysical monitoring concept

    NASA Astrophysics Data System (ADS)

    Sauer, Uta; Schütze, Claudia; Dietrich, Peter

    2013-04-01

    Processes in soil, plants and near surface atmosphere interact with each other in a complex way. Soil is an environmental component and important part of our ecosystems. Parent material of soils determines the original supply of nutrients. However, environmental parameters such as meteorological and land use have also an influence to the soil conditions. The objective of our research work is the development of a hierarchical diagnostic monitoring concept for the characterization of water and CO2 fluxes and their driving impact factors to provide information on structures and fluxes in the soil-vegetation- atmosphere system. As part of this hierarchical diagnostic monitoring concept, several methods and technologies from different disciplines (such as chemistry, hydrogeology, and geophysics) will either be combined or used complementary to one another. Our approach will allow large spatial areas to be consistently covered, for efficient monitoring of increases in spatial and temporal resolutions. Firstly, remote sensing monitoring methods for large-scale application (more than 1km2) are used to obtain information about energy and matter fluxes in the atmosphere. A common spectroscopic method for analysis is FTIR spectroscopy, where chemical anorganic and organic compounds can be detected through their characteristic infra-red absorption frequencies or wavelengths. Open-path Fourier transform infrared (OP FTIR) spectrometry is a sensitive and non-invasive method to detect and quantify a wide range of gases simultaneously. Subsequently, meso-scale methods (0.01-1km2) can be employed which investigate subsurface characteristics to describe geological and soil structures and dynamics. Various soil parameters can be mapped using rapid, nearly non-destructive methods (e.g. geophysics, spectroscopy), for quasi-continuous 2D as well as 3D mapping of soil physical and hydrological properties. Finally, point measurements at plot scale (less than 0.01km2) enable high

  3. Pore-scale Modeling on the Characterization of Kyeongsang Basin, South Korea for the Geological CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Han, J.; Keehm, Y.

    2011-12-01

    Carbon dioxide is a green-house gas and is believed to be responsible for global warming and climate change. Many countries are looking for various techniques for effective storage of CO2 and the geological sequestration is regarded as the most economical and efficient option. For successful geological sequestration, accurate evaluation of physical properties of the target formation and their changes when CO2 is injected, is essential. Since physical property changes during CO2 injection are strongly dependent on the pore-scale details of the target formation, we used a series of pore-scale simulation techniques including CO2 injection simulation to estimate physical properties of CO2 bearing formations. The study area, Kyeongsang basin is located in southeastern part of Korea, which has many industrial complexes including power plants. We first obtained high-resolution 3D microstructures from core samples of the prospective formation. We performed a set of pore-scale simulation and estimated physical properties, such as porosity, permeability, electrical conductivity and velocity. Then we used lattice-Boltzmann two-phase flow simulation to mimic CO2 injection into the formation. During this simulation, a variety of microstructures with different CO2 saturation were obtained and we again performed pore-scale simulation to estimate the changes of physical properties as CO2 saturation increases. These quantitative interrelations between physical properties and CO2 saturation would be a valuable piece of information to evaluate the performance of the target formation. Acknowledgement: This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2010201020001A)

  4. Encapsulation of CO2 into amorphous alpha-cyclodextrin powder at different moisture contents - Part 2: Characterization of complexed powders and determination of crystalline structure.

    PubMed

    Ho, Thao M; Howes, Tony; Jack, Kevin S; Bhandari, Bhesh R

    2016-09-01

    This study aims to characterize CO2-α-cyclodextrin (α-CD) inclusion complexes produced from amorphous α-CD powder at moisture contents (MC) close to or higher than the critical level of crystallization (e.g. 13, 15 and 17% MC on wet basis, w.b.) at 0.4 and 1.6MPa pressure for 72h. The results of (13)C NMR, SEM, DSC and X-ray analyses showed that these MC levels were high enough to induce crystallization of CO2-α-CD complexed powders during encapsulation, by which amount of CO2 encapsulated by amorphous α-CD powder was significantly increased. The formation of inclusion complexes were well confirmed by results of FTIR and (13)C NMR analyses through an appearance of a peak associated with CO2 on the FTIR (2334cm(-1)) and NMR (125.3ppm) spectra. Determination of crystal packing patterns of CO2-α-CD complexed powders showed that during crystallization, α-CD molecules were arranged in cage-type structure in which CO2 molecules were entrapped in isolated cavities.

  5. Thermal Characterization and Effect of Deposited hbox {CO}2 on a Cryogenic Insulation System Based on a Spherical Powder

    NASA Astrophysics Data System (ADS)

    Geisler, M.; Ebert, H.-P.

    2016-08-01

    The objective of this work is to study the effect of deposited hbox {CO}2 on the solid thermal conductivity of a cryogenic insulation system. Therefore, measurements were performed using a guarded hot plate apparatus at temperatures in the range from 80 K to 290 K in combination with a bellow acting as the sample containment. The unique experimental setup and sample preparation are described in detail. Furthermore, existing thermal models which are based on a superposition of thermal transfer due to radiation and solid thermal conductivity were modified to account for the thermal effects of deposited gases and the consequently increased solid thermal conductivity for a spherical powder. Measurements showed a significant increase of the solid thermal conductivity depending on the amount of hbox {CO}2 that was provided for deposition-evacuation. 2.77 Vol-‰hbox {CO}2 resulted in an increase of 5.5 % in the overall solid thermal conductivity. Twice this amount (5.54 Vol-‰hbox {CO}2) and four times this amount (11.1 Vol-‰hbox {CO}2) resulted in an increase of 8.8 % and 14.1 % in the overall solid thermal conductivity, respectively. Due to additional temperature sensors, it was possible to measure the effective thermal conductivity in different layers of the insulation material. Thus, a significant change in the innermost layer of 75 % was measured for the solid thermal conductivity comparing the evacuated sample with the hbox {CO}2-loaded (11.1 Vol-‰hbox { CO}2) sample.

  6. Source Characterization and Temporal Variation of Methane Seepage from Thermokarst Lakes on the Alaska North Slope in Response to Arctic Climate Change

    SciTech Connect

    None, None

    2012-09-30

    The goals of this research were to characterize the source, magnitude and temporal variability of methane seepage from thermokarst lakes (TKL) within the Alaska North Slope gas hydrate province, assess the vulnerability of these areas to ongoing and future arctic climate change and determine if gas hydrate dissociation resulting from permafrost melting is contributing to the current lake emissions. Analyses were focused on four main lake locations referred to in this report: Lake Qalluuraq (referred to as Lake Q) and Lake Teshekpuk (both on Alaska's North Slope) and Lake Killarney and Goldstream Bill Lake (both in Alaska's interior). From analyses of gases coming from lakes in Alaska, we showed that ecological seeps are common in Alaska and they account for a larger source of atmospheric methane today than geologic subcap seeps. Emissions from the geologic source could increase with potential implications for climate warming feedbacks. Our analyses of TKL sites showing gas ebullition were complemented with geophysical surveys, providing important insight about the distribution of shallow gas in the sediments and the lake bottom manifestation of seepage (e.g., pockmarks). In Lake Q, Chirp data were limited in their capacity to image deeper sediments and did not capture the thaw bulb. The failure to capture the thaw bulb at Lake Q may in part be related to the fact that the present day lake is a remnant of an older, larger, and now-partially drained lake. These suggestions are consistent with our analyses of a dated core of sediment from the lake that shows that a wetland has been present at the site of Lake Q since approximately 12,000 thousand years ago. Chemical analyses of the core indicate that the availability of methane at the site has changed during the past and is correlated with past environmental changes (i.e. temperature and hydrology) in the Arctic. Discovery of methane seeps in Lake Teshekpuk in the northernmost part of the lake during 2009

  7. U.S. Department of Energy's site screening, site selection, and initial characterization for storage of CO2 in deep geological formations

    USGS Publications Warehouse

    Rodosta, T.D.; Litynski, J.T.; Plasynski, S.I.; Hickman, S.; Frailey, S.; Myer, L.

    2011-01-01

    The U.S. Department of Energy (DOE) is the lead Federal agency for the development and deployment of carbon sequestration technologies. As part of its mission to facilitate technology transfer and develop guidelines from lessons learned, DOE is developing a series of best practice manuals (BPMs) for carbon capture and storage (CCS). The "Site Screening, Site Selection, and Initial Characterization for Storage of CO2 in Deep Geological Formations" BPM is a compilation of best practices and includes flowchart diagrams illustrating the general decision making process for Site Screening, Site Selection, and Initial Characterization. The BPM integrates the knowledge gained from various programmatic efforts, with particular emphasis on the Characterization Phase through pilot-scale CO2 injection testing of the Validation Phase of the Regional Carbon Sequestration Partnership (RCSP) Initiative. Key geologic and surface elements that suitable candidate storage sites should possess are identified, along with example Site Screening, Site Selection, and Initial Characterization protocols for large-scale geologic storage projects located across diverse geologic and regional settings. This manual has been written as a working document, establishing a framework and methodology for proper site selection for CO2 geologic storage. This will be useful for future CO2 emitters, transporters, and storage providers. It will also be of use in informing local, regional, state, and national governmental agencies of best practices in proper sequestration site selection. Furthermore, it will educate the inquisitive general public on options and processes for geologic CO2 storage. In addition to providing best practices, the manual presents a geologic storage resource and capacity classification system. The system provides a "standard" to communicate storage and capacity estimates, uncertainty and project development risk, data guidelines and analyses for adequate site characterization, and

  8. Application of the top specified boundary layer (TSBL) approximation to initial characterization of an inland aquifer mineralization: 2. Seepage of saltwater through semi-confining layers

    USGS Publications Warehouse

    Rubin, H.; Buddemeier, R.W.

    1998-01-01

    This paper presents a generalized basic study that addresses practical needs for an understanding of the major mechanisms involved in the mineralization of groundwater in the Great Bend Prairie aquifer in south- central Kansas. This Quaternary alluvial aquifer and associated surface waters are subject to contamination by saltwater, which in some areas seeps from the deeper Permian bedrock formation into the overlying freshwater aquifer through semiconfining layers. A simplified conceptual model is adopted. It incorporates the freshwater aquifer whose bottom is comprised of a semiconfining layer through which a hydrologically minor but geochemically important saline water discharge seeps into the aquifer. A hierarchy of approximate approaches is considered to analyze the mineralization processes taking place in the aquifer. The recently developed top specified boundary layer (TSBL) approach is very convenient to use for the initial characterization of these processes, and is further adapted to characterization of head-driven seepage through semi-confining layers. TSBL calculations indicate that the seeping saline water may create two distinct new zones in the aquifer: (1) a completely saline zone (CSZ) adjacent to the semiconfining bottom of the aquifer, and (2) a transition zone (TZ) which develops between the CSZ and the freshwater zone. Some possible scenarios associated with the various mineralization patterns are analyzed and discussed.

  9. Characterization of an urban-rural CO 2 /temperature gradient and associated changes in initial plant productivity during secondary succession

    SciTech Connect

    Ziska, L. H.; Bunce, J. A.; Goins, E. W.

    2004-05-01

    To examine the impact of climate change on vegetative productivity, we exposed fallow agricultural soil to an in situ temperature and CO2 gradient between urban, suburban and rural areas in 2002. Along the gradient, average daytime CO2 concentration increased by 21% and maximum (daytime) and minimum (nighttime) daily temperatures increased by 1.6 and 3.3°C, respectively in an urban relative to a rural location. Consistent location differences in soil temperature were also ascertained. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented. The urban-induced environmental changes that were observed were consistent with most short-term (~50 year) global change scenarios regarding CO2 concentration and air temperature. Productivity, determined as final above-ground biomass, and maximum plant height were positively affected by daytime and soil temperatures as well as enhanced [CO2], increasing 60 and 115% for the suburban and urban sites, respectively, relative to the rural site. While long-term data are needed, these initial results suggest that urban environments may act as a reasonable surrogate for investigating future climatic change in vegetative communities.

  10. Characterizing flow behavior for gas injection: Relative permeability of CO2-brine and N2-water in heterogeneous rocks

    NASA Astrophysics Data System (ADS)

    Reynolds, C. A.; Krevor, S.

    2015-12-01

    We provide a comprehensive experimental study of steady state, drainage relative permeability curves with CO2-brine and N2-deionized water, on a single Bentheimer sandstone core with a simple two-layer heterogeneity. We demonstrate that, if measured in the viscous limit, relative permeability is invariant with changing reservoir conditions, and is consistent with the continuum-scale multiphase flow theory for water wet systems. Furthermore, we show that under capillary limited conditions, the CO2-brine system is very sensitive to heterogeneity in capillary pressure, and by performing core floods under capillary limited conditions, we produce effective relative permeability curves that are flow rate and fluid parameter dependent. We suggest that the major uncertainty in past observations of CO2-brine relative permeability curves is due to the interaction of CO2 flow with pore space heterogeneity under capillary limited conditions and is not due to the effects of changing reservoir conditions. We show that the appropriate conditions for measuring intrinsic or effective relative permeability curves can be selected simply by scaling the driving force for flow by a quantification of capillary heterogeneity. Measuring one or two effective curves on a core with capillary heterogeneity that is representative of the reservoir will be sufficient for reservoir simulation.

  11. Reservoir Characterization and Flow Simulation for CO 2-EOR in the Tensleep Formation Using Discrete Fracture Networks, Teapot Dome, Wyoming

    NASA Astrophysics Data System (ADS)

    Kavousi Ghahfarokhi, Payam

    The Tensleep oil reservoir at Teapot Dome, Wyoming, USA, is a naturally fractured tight sandstone reservoir that has been considered for carbon-dioxide enhanced oil recovery (CO2-EOR) and sequestration. CO2-EOR analysis requires a thorough understanding of the Tensleep fracture network. Wireline image logs from the field suggest that the reservoir fracture network is dominated by early formed structural hinge oblique fractures with interconnectivity enhanced by hinge parallel and hinge perpendicular fracture sets. Available post stack 3D seismic data are used to generate a seismic fracture intensity attribute for the reservoir fracture network. The resulting seismic fracture intensity is qualitatively correlated to the field production history. Wells located on hinge-oblique discontinuities are more productive than other wells in the field. We use Oda's method to upscale the fracture permeabilities in the discrete fracture network for use in a dual porosity fluid flow simulator. We analytically show that Oda's method is sensitive to the grid orientation relative to fracture set strike. Results show that the calculated permeability tensors have maximum geometric mean for the non-zero permeability components (kxx,kyy,kzz,kxy) when the dominant fracture set cuts diagonally through the grid cell at 45° relative to the grid cell principal directions (i,j). The geometric mean of the permeability tensor components falls to a minimum when the dominant fracture set is parallel to either grid wall (i or j principal directions). The latter case has off-diagonal permeability terms close to zero. We oriented the Tensleep reservoir grid to N72°W to minimize the off-diagonal permeability terms. The seismic fracture intensity attribute is then used to generate a realization of the reservoir fracture network. Subsequently, fracture properties are upscaled to the reservoir grid scale for a fully compositional flow simulation. We implemented a PVT analysis using CO2 swelling test

  12. Purification and characterization of neutral alpha-mannosidase from hen oviduct: studies on the activation mechanism of Co2+.

    PubMed

    Yamashiro, K; Itoh, H; Yamagishi, M; Natsuka, S; Mega, T; Hase, S

    1997-12-01

    Neutral alpha-mannosidase was purified to homogeneity from hen oviduct. The molecular mass of the enzyme was 480 kDa on gel filtration, and the 110-kDa band on SDS-PAGE in the presence of 2-mercaptoethanol indicated that it is composed of four subunits. The activated enzyme hydrolyzed both p-nitrophenyl alpha-D-mannoside and high mannose-type sugar chains. This substrate specificity is almost the same as that reported for the neutral a-mannosidase from Japanese quail oviduct [Oku and Hase (1991) J. Biochem. 110, 982-989]. Manalpha1-6(Manalpha1-3)Manalpha1-6(Manalpha1-3) Manbeta1-4GlcNAc (Km =0.44 mM) was hydrolyzed four times faster than Manalpha1-6(Manalpha1-3)Manalpha1-6(Manalpha1-3) Manbeta1-4GIcNAcbeta1-4GlcNAc, and Manalpha1-6(Manalpha1-2Manalpha1-2Manalpha1-3)++ +Manbeta1-4GlcNAc was obtained as the end product from Man9GlcNAc on digestion with the activated alpha-mannosidase. The enzyme was activated 24-fold on preincubation with Co2+. The activation with other metal ions, like Mn2+, Ca2+, Fe2+, Fe3+, and Sr2+, was less than 5-fold, and Zn2+, Cu2+, and Hg2+ inhibited the enzyme activity. The optimum pHs for both the enzyme activity and activation with Co2+ were around 7. The cobalt ion contents of the purified, EDTA-treated, and Co2+-activated enzymes were 1.5, 0.0, and 3.9, respectively, per molecule. Since the Co2+-activated enzyme gradually lost its activity on incubation with EDTA and the activity was restored promptly on the addition of Co2+, the binding of Co2+ to the enzyme seems to be essential for its activation. The results obtained with protease inhibitors together with those of the SDS-PAGE before and after activation, showed that the proteolytic cleavage reported for the activation of monkey brain alpha-mannosidase seems not to be involved.

  13. Growing TiO2 nanowires on the surface of graphene sheets in supercritical CO2: characterization and photoefficiency

    NASA Astrophysics Data System (ADS)

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chowdhury, Rajib Roy; Charpentier, Paul A.

    2012-07-01

    Tremendous interest exists towards synthesizing nanoassemblies for dye-sensitized solar cells (DSSCs) using earth-abundant and -friendly materials with green synthetic approaches. In this work, high surface area TiO2 nanowire arrays were grown on the surface of functionalized graphene sheets (FGSs) containing -COOH functionalities acting as a template by using a sol-gel method in the green solvent, supercritical carbon dioxide (scCO2). The effect of scCO2 pressure (1500, 3000 and 5000 psi), temperature (40, 60 and 80 °C), acetic acid/titanium isopropoxide monomer ratios (HAc/TIP = 2, 4 and 6), functionalized graphene sheets (FGSs)/TIP weight ratios (1:20, 1:40 and 1:60 w/w) and solvents (EtOH, hexane) were investigated. Increasing the HAc/TIPweight ratio from 4 to 6 in scCO2 resulted in increasing the TiO2 nanowire diameter from 10 to 40 nm. Raman and high resolution XPS showed the interaction of TiO2 with the -COOH groups on the surface of the graphene sheets, indicating that graphene acted as a template for polycondensation growth. UV-vis diffuse reflectance and photoluminescence spectroscopy showed a reduction in titania’s bandgap and also a significant reduction in electron-hole recombination compared to bare TiO2 nanowires. Photocurrent measurements showed that the TiO2nanowire/graphene composites prepared in scCO2 gave a 5× enhancement in photoefficiency compared to bare TiO2 nanowires.

  14. Growing TiO2 nanowires on the surface of graphene sheets in supercritical CO2: characterization and photoefficiency.

    PubMed

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chowdhury, Rajib Roy; Charpentier, Paul A

    2012-07-27

    Tremendous interest exists towards synthesizing nanoassemblies for dye-sensitized solar cells (DSSCs) using earth-abundant and -friendly materials with green synthetic approaches. In this work, high surface area TiO(2) nanowire arrays were grown on the surface of functionalized graphene sheets (FGSs) containing -COOH functionalities acting as a template by using a sol-gel method in the green solvent, supercritical carbon dioxide (scCO(2)). The effect of scCO(2) pressure (1500, 3000 and 5000 psi), temperature (40, 60 and 80 °C), acetic acid/titanium isopropoxide monomer ratios (HAc/TIP = 2, 4 and 6), functionalized graphene sheets (FGSs)/TIP weight ratios (1:20, 1:40 and 1:60 w/w) and solvents (EtOH, hexane) were investigated. Increasing the HAc/TIPweight ratio from 4 to 6 in scCO(2) resulted in increasing the TiO(2) nanowire diameter from 10 to 40 nm. Raman and high resolution XPS showed the interaction of TiO(2) with the -COOH groups on the surface of the graphene sheets, indicating that graphene acted as a template for polycondensation growth. UV-vis diffuse reflectance and photoluminescence spectroscopy showed a reduction in titania's bandgap and also a significant reduction in electron-hole recombination compared to bare TiO(2) nanowires. Photocurrent measurements showed that the TiO(2)nanowire/graphene composites prepared in scCO(2) gave a 5× enhancement in photoefficiency compared to bare TiO(2) nanowires.

  15. Synthesis and characterization of nickel and zinc ferrite nanocatalysts for decomposition of CO2 greenhouse effect gas.

    PubMed

    Lin, Kuen-Song; Adhikari, Abhijit Krishna; Wang, Chi-Yu; Hsu, Pei-Ju; Chan, Ho-Yang

    2013-04-01

    The decomposition of CO2 over oxygen deficient nickel ferrite nanoparticles (NFNs) and zinc ferrite nanoparticles (ZFNs) at 573 K was studied. The oxidation states with fine structure of Fe/Ni or Fe/Zn species were also measured in NFNs and ZFNs catalysts, respectively. Oxygen deficiency of catalysts was obtained by reduction in hydrogen. Decomposition of CO2 into carbon and oxygen has been carried out within few minutes when it comes into contact with oxygen deficient catalysts through incorporation of oxygen into ferrite nanoparticles. Oxygen and carbon rather than CO were produced in the decomposition process. The complete decomposition of CO2 was possible because of higher degree of oxygen deficiency andsurface-to-volume ratio of the catalysts. The pre-edge XANES spectra of Fe species in both catalysts exhibit an absorbance feature at 7114 eV for the 1s to 3d transition which is forbidden by the selection rule in case of perfect octahedral symmetry. The EXAFS data showed that the NFNs had two central Fe atoms coordinated by primarily Fe-O and Fe-Fe with bond distances of 1.871 and 3.051 angstroms, respectively. In case of ZFNs these values are 1.889 and 3.062 A, respectively. Methane gas was produced during the reactivation of NFNs by flowing hydrogen gas. Decomposition of CO2, moreover, recovery of valuable methane using heat energy of offgas produced from power generation plant or steel industry is an appealing alternative for energy recovery.

  16. Characterization of a Mixture of CO2 Adsorption Products in Hyperbranched Aminosilica Adsorbents by (13)C Solid-State NMR.

    PubMed

    Moore, Jeremy K; Sakwa-Novak, Miles A; Chaikittisilp, Watcharop; Mehta, Anil K; Conradi, Mark S; Jones, Christopher W; Hayes, Sophia E

    2015-11-17

    Hyperbranched amine polymers (HAS) grown from the mesoporous silica SBA-15 (hereafter "SBA-15-HAS") exhibit large capacities for CO2 adsorption. We have used static in situ and magic-angle spinning (MAS) ex situ (13)C nuclear magnetic resonance (NMR) to examine the adsorption of CO2 by SBA-15-HAS. (13)C NMR distinguishes the signal of gas-phase (13)CO2 from that of the chemisorbed species. HAS polymers possess primary, secondary, and tertiary amines, leading to multiple chemisorption reaction outcomes, including carbamate (RnNCOO(-)), carbamic acid (RnNCOOH), and bicarbonate (HCO3(-)) moieties. Carbamates and bicarbonate fall within a small (13)C chemical shift range (162-166 ppm), and a mixture was observed including carbamic acid and carbamate, the former disappearing upon evacuation of the sample. By examining the (13)C-(14)N dipolar coupling through low-field (B0 = 3 T) (13)C{(1)H} cross-polarization MAS NMR, carbamate is confirmed through splitting of the (13)C resonance. A third species that is either bicarbonate or a second carbamate is evident from bimodal T2 decay times of the ∼163 ppm peak, indicating the presence of two species comprising that single resonance. The mixture of products suggests that (1) the presence of amines and water leads to bicarbonate being present and/or (2) the multiple types of amine sites in HAS permit formation of chemically distinct carbamates.

  17. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    Czirr, Kirk

    1999-10-28

    The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the second quarter falls within the demonstration project.

  18. Expression and characterization of a codon-optimized alkaline-stable carbonic anhydrase from Aliivibrio salmonicida for CO2 sequestration applications.

    PubMed

    Jun, So-Young; Kim, Sung Ho; Kanth, Bashista Kumar; Lee, Jinwon; Pack, Seung Pil

    2017-03-01

    The CO2 mineralization process, accelerated by carbonic anhydrase (CA) was proposed for the efficient capture and storage of CO2, the accumulation of which in the atmosphere is the main cause of global warming. Here, we characterize a highly stable form of the cloned CA from the Gram-negative marine bacterium Aliivibrio salmonicida, named ASCA that can promote CO2 absorption in an alkaline solvent required for efficient carbon capture. We designed a mature form of ASCA (mASCA) using a codon optimization of ASCA gene and removal of ASCA signal peptide. mASCA was highly expressed (255 mg/L) with a molecular weight of approximately 26 kDa. The mASCA enzyme exhibited stable esterase activity within a temperature range of 10-60 °C and a pH range of 6-11. mASCA activity remained stable for 48 h at pH 10. We also investigated its inhibition profiles using inorganic anions, such as acetazolamide, sulfanilamide, iodide, nitrate, and azide. We also demonstrate that mASCA is capable of catalyzing the conversion of CO2 to CaCO3 (calcite form) in the presence of Ca(2+). It should be noted that mASCA enzyme exhibits high production yield and sufficient stabilities against relatively high temperature and alkaline pH, which are required conditions for the development of more efficient enzymatic CCS systems.

  19. CO2-Neutral Fuels

    NASA Astrophysics Data System (ADS)

    Goede, Adelbert; van de Sanden, Richard

    2016-06-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.

  20. Thermal decomposition of sewage sludge under N2, CO2 and air: Gas characterization and kinetic analysis.

    PubMed

    Hernández, Ana Belén; Okonta, Felix; Freeman, Ntuli

    2017-03-25

    Thermochemical valorisation processes that allow energy to be recovered from sewage sludge, such as pyrolysis and gasification, have demonstrated great potential as convenient alternatives to conventional sewage sludge disposal technologies. Moreover, these processes may benefit from CO2 recycling. Today, the scaling up of these technologies requires an advanced knowledge of the reactivity of sewage sludge and the characteristics of the products, specific to the thermochemical process. In this study the behaviour of sewage sludge during thermochemical conversion, under different atmospheres (N2, CO2 and air), was studied, using TGA-FTIR, in order to understand the effects of different atmospheric gases on the kinetics of degradation and on the gaseous products. The different steps observed during the solid degradation were related with the production of different gaseous compounds. A higher oxidative degree of the atmosphere surrounding the sample resulted in higher reaction rates and a shift of the degradation mechanisms to lower temperatures, especially for the mechanisms taking place at temperatures above 400 °C. Finally, a multiple first-order reaction model was proposed to compare the kinetic parameters obtained under different atmospheres. Overall, the highest activation energies were obtained for combustion. This work proves that CO2, an intermediate oxidative atmosphere between N2 and air, results in an intermediate behaviour (intermediate peaks in the derivative thermogravimetric curves and intermediate activation energies) during the thermochemical decomposition of sewage sludge. Overall, it can be concluded that the kinetics of these different processes require a different approach for their scaling up and specific consideration of their characteristic reaction temperatures and rates should be evaluated.

  1. Estimation of continuous anthropogenic CO2 using CO2, CO, δ13C(CO2) and Δ14C(CO2)

    NASA Astrophysics Data System (ADS)

    Vardag, S. N.; Gerbig, C.; Janssens-Maenhout, G.; Levin, I.

    2015-07-01

    We investigate different methods for estimating anthropogenic CO2 using modelled continuous atmospheric concentrations of CO2 alone, as well as CO2 in combination with the surrogate tracers CO, δ13C(CO2) and Δ14C(CO2). These methods are applied at three hypothetical stations representing rural, urban and polluted conditions. We find that independent of the tracer used, an observation-based estimate of continuous anthropogenic CO2 is not feasible at rural measurement sites due to the low signal to noise ratio of anthropogenic CO2 estimates at such settings. At urban and polluted sites, potential future continuous Δ14C(CO2) measurements with a precision of 5 ‰ or better are most promising for anthropogenic CO2 determination (precision ca. 10-20%), but the insensitivity against CO2 contributions from biofuel emissions may reduce its accuracy in the future. Other tracers, such as δ13C(CO2) and CO could provide an accurate and already available alternative if all CO2 sources in the catchment area are well characterized with respect to their isotopic signature and CO to anthropogenic CO2 ratio. We suggest a strategy for calibrating these source characteristics on an annual basis using precise Δ14C(CO2) measurements on grab samples. The precision of anthropogenic CO2 determination using δ13C(CO2) is largely determined by the measurement precision of δ13C(CO2) and CO2. The precision when using the CO-method is mainly limited by the variation of natural CO sources and CO sinks. At present, continuous anthropogenic CO2 could be determined using the tracers δ13C(CO2) and/or CO with a precision of about 30 %, a mean bias of about 10 % and without significant diurnal discrepancies. This allows significant improvement, validation and bias reduction of highly resolved emission inventories using atmospheric observation and regional modelling.

  2. 4D reservoir characterization using well log data for feasible CO2-enhanced oil recovery at Ankleshwar, Cambay Basin - A rock physics diagnostic and modeling approach

    NASA Astrophysics Data System (ADS)

    Ganguli, Shib Sankar; Vedanti, Nimisha; Dimri, V. P.

    2016-12-01

    In recent years, rock physics modeling has become an integral part of reservoir characterization as it provides the fundamental relationship between geophysical measurements and reservoir rock properties. These models are also used to quantify the effect of fluid saturation and stress on reservoir rocks by tracking the changes in elastic properties during production. Additionally, various rock physics models can be applied to obtain the information of rock properties away from existing drilled wells, which can play a crucial role in the feasibility assessment of CO2-enhanced oil recovery (EOR) operation at field. Thus, the objective of this study is to develop a rock-physics model of the Ankleshwar reservoir to predict the reservoir response under CO2-EOR. The Ankleshwar oil field is a mature field situated in Cambay Basin (Western India) that witnessed massive peripheral water flooding for around 40 years. Since the field was under water flooding for a long term, reasonable changes in reservoir elastic properties might have occurred. To identify potential reservoir zone with significant bypassed (or residual) oil saturation, we applied the diagnostic rock physics models to two available wells from the Ankleshwar oil field. The results clearly indicate transitions from clean sands to shaly sands at the base, and from sandy shale to pure shale at the top of the reservoir pay zone, suggesting a different seismic response at the top when compared to the base of the reservoir in both the wells. We also found that clay content and sorting affects the elastic properties of these sands, indicating different depositional scenario for the oil sands encountered in the Ankleshwar formation. Nevertheless, the rock physics template (RPT) analysis of the well data provides valuable information about the residual oil zone, a potential target for CO2-EOR. Further, a 4D reservoir characterization study has been conducted to assess the seismic detectability of CO2-EOR, and we

  3. (13)C and (15)N NMR characterization of amine reactivity and solvent effects in CO2 capture.

    PubMed

    Perinu, Cristina; Arstad, Bjørnar; Bouzga, Aud M; Jens, Klaus-J

    2014-08-28

    Factors influencing the reactivity of selected amine absorbents for carbon dioxide (CO2) capture, in terms of the tendency to form amine carbamate, have been studied. Four linear primary alkanolamines at varying chain lengths (MEA, 3A1P, 4A1B , and 5A1P ), two primary amines with different substituents in the β-position to the nitrogen (1A2P and ISOB), a secondary alkanolamine (DEA), and a sterically hindered primary amine (AMP) were investigated. The relationship between the (15)N NMR data of aqueous amines and their ability to form carbamate, as determined at equilibrium by quantitative (13)C NMR experiments, was analyzed, taking into account structural-chemical properties. For all the amines, the (15)N chemical shifts fairly reflected the observed reactivity for carbamate formation. In addition to being a useful tool for the investigation of amine reactivity, (15)N NMR data clearly provided evidence of the importance of solvent effects for the understanding of chemical dynamics in CO2 capture by aqueous amine absorbents.

  4. The influence of CO(2) on ISFETs with polymer membranes and characterization of a carbonate ion sensor.

    PubMed

    Abramova, Natalia; Levichev, Sergey; Bratov, Andrey

    2010-06-15

    The influence of CO(2) and acetic acid on the response of ISFET sensors with PVC and photocured polyurethane polymer membranes with valinomycin as an ionophore was assessed. Experimental results show that the presence of these compounds has no effect on sensors parameters even after prolonged soaking in a water solution. Using a photocured polyurethane polymer as an ion-selective membrane matrix for an ISFET, a carbonate ion sensor was developed with hexyl-p-trifluoroacetylbenzoate (HE) as an ionophore. Effect of cationic and anionic lipophilic additives on the sensors response was studied. Sensors with the optimized membrane composition based on HE (7.9%, w/w) and tridodecylmethylammonium chloride (5.7%, w/w) show sensitivity of 27-30mV per decade of carbonate ion concentration, sufficient selectivity in front of chloride ions, and a lifetime of 3-5 months.

  5. CO2 -Responsive polymers.

    PubMed

    Lin, Shaojian; Theato, Patrick

    2013-07-25

    This Review focuses on the recent progress in the area of CO2 -responsive polymers and provides detailed descriptions of these existing examples. CO2 -responsive polymers can be categorized into three types based on their CO2 -responsive groups: amidine, amine, and carboxyl groups. Compared with traditional temperature, pH, or light stimuli-responsive polymers, CO2 -responsive polymers provide the advantage to use CO2 as a "green" trigger as well as to capture CO2 directly from air. In addition, the current challenges of CO2 -responsive polymers are discussed and the different solution methods are compared. Noteworthy, CO2 -responsive polymers are considered to have a prosperous future in various scientific areas.

  6. CO2 laser preionisation

    NASA Technical Reports Server (NTRS)

    Spiers, Gary D.

    1991-01-01

    The final report for work done during the reporting period of January 25, 1990 to January 24, 1991 is presented. A literature survey was conducted to identify the required parameters for effective preionization in TEA CO2 lasers and the methods and techniques for characterizing preionizers are reviewed. A numerical model of the LP-140 cavity was used to determine the cause of the transverse mode stability improvement obtained when the cavity was lengthened. The measurement of the voltage and current discharge pulses on the LP-140 were obtained and their subsequent analysis resulted in an explanation for the low efficiency of the laser. An assortment of items relating to the development of high-voltage power supplies is also provided. A program for analyzing the frequency chirp data files obtained with the HP time and frequency analyzer is included. A program to calculate the theoretical LIMP chirp is also included and a comparison between experiment and theory is made. A program for calculating the CO2 linewidth and its dependence on gas composition and pressure is presented. The program also calculates the number of axial modes under the FWHM of the line for a given resonator length. A graphical plot of the results is plotted.

  7. CO2 laser modeling

    NASA Technical Reports Server (NTRS)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  8. Integrating seepage heterogeneity with the use of ganged seepage meters

    USGS Publications Warehouse

    Rosenberry, D.O.

    2005-01-01

    The usefulness of standard half-barrel seepage meters for measurement of fluxes between groundwater, and surface water is limited by the small bed area that each measurement represents and the relatively large associated labor costs. Standard half-barrel cylinders were ganged together to allow one measurement of the summed seepage through all of the meters, reducing labor cost and increasing the representative area of measurement. Comparisons of ganged versus individual-meter measurements at two lakes, under both inseepage and outseepage conditions, indicate little loss of efficiency resulting from routing seepage water through the ganging system. Differences between summed and ganged seepage rates were not significant for all but the fastest rates of seepage. At flow rates greater than about 250 mL min-1, ganged values were as low as 80% of summed values. Ganged-meter head losses also were calculated to determine their significance relative to hydraulic-head gradients measured at the field sites. The calculated reduction in hydraulic gradient beneath the seepage meters was significant only for the largest measured seepage rates. A calibration tank was used to determine single-meter and ganged-meter efficiencies compared to known seepage rates. Single-cylinder seepage meters required an average correction factor of 1.05 to convert measured to actual values, whereas the ganged measurements made in the tank required a larger correction factor of 1.14. Although manual measurements were used in these tests, the concept of ganging seepage cylinders also would be useful when used in conjunction with automated flowmeters. ?? 2005, by the American Society of Limnology and Oceanography, Inc.

  9. Preparation and structural, optical, magnetic, and electrical characterization of Mn2+/Co2+/Cu2+ doped hematite nanocrystals

    NASA Astrophysics Data System (ADS)

    Srikrishna Ramya, S. I.; Mahadevan, C. K.

    2014-03-01

    Pure and Mn2+ / Co2+ / Cu2+ doped (1 and 2 at.%) spherical hematite (α-Fe2O3)nanocrystals have been synthesized by a simple solvothermal method using a domestic microwave oven. XRD measurements confirm that all the seven nanocrystals prepared consist of nanocrystalline hematite phase without any other phases. The energy dispersive X-ray and Fourier transform infrared spectral analyses confirm the phase purity of the nanocrystals prepared. TEM analysis shows the average particle sizes within the range 33-51 nm. Optical absorption measurements indicate that all the three dopants enhance the optical transmittance and reflectance. A red shift is observed in the bandgap energy values estimated from optical absorption and reflectance spectra. Results of magnetic measurements made at room temperature using a vibrating sample magnetometer indicate significant changes in the magnetic properties (coercivity, retentivity and saturationmagnetization) due to doping. Results of magnetic measurements indicate significant changes in the magnetic properties. Results of AC electrical measurements made at various temperatures in the range 40-130 °C and frequencies in the range 100 Hz -1 MHz indicate low dielectric constants and AC electrical conductivities and consequently show the occurrence of nanoconfined states.

  10. SEEPAGE/BACKFILL INTERACTIONS

    SciTech Connect

    P. Mariner

    2000-04-14

    As directed by written development plan (CRWMS M&O 1999a), a sub-model of seepage/backfill interactions is developed and presented in this document to support the Engineered Barrier System (EBS) Physical and Chemical Environment Model. The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift. In this analysis, a conceptual model is developed to provide PAO a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The development plan calls for a sub-model that evaluates the effect on water chemistry of chemical reactions between water that enters the drift and backfill materials in the drift. The development plan specifically requests an evaluation of the following important chemical reaction processes: dissolution-precipitation, aqueous complexation, and oxidation-reduction. The development plan also requests the evaluation of the effects of varying seepage and drainage fluxes, varying temperature, and varying evaporation and condensation fluxes. Many of these effects are evaluated in a separate Analysis/Model Report (AMR), ''Precipitates Salts Analysis AMR'' (CRWMS M&O 2000), so the results of that AMR are referenced throughout this AMR.

  11. Rock formation characterization for CO2-EOR and carbon geosequestration; 3D seismic amplitude and coherency anomalies, Wellington Field, Kansas, USA

    USGS Publications Warehouse

    Ohl, D.; Raef, A.; Watnef, L.; Bhattacharya, S.

    2011-01-01

    In this paper, we present a workflow for a Mississipian carbonates characterization case-study integrating post-stack seismic attributes, well-logs porosities, and seismic modeling to explore relating changes in small-scale "lithofacies" properties and/or sub-seismic resolution faulting to key amplitude and coherency 3D seismic attributes. The main objective of this study is to put emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2-EOR in preparation for future carbon geosequestration in a depleting reservoir and a deep saline aquifer. The extracted 3D seismic coherency attribute indicated anomalous features that can be interpreted as a lithofacies change or a sub-seismic resolution faulting. A 2D finite difference modeling has been undertaken to understand and potentially build discriminant attributes to map structural and/or lithofacies anomalies of interest especially when embarking upon CO2-EOR and/or carbon sequestration monitoring and management projects. ?? 2011 Society of Exploration Geophysicists.

  12. A natural analogue for CO2 leakage: The release and fate of CO2 at the Jan Mayen vent fields (AMOR)

    NASA Astrophysics Data System (ADS)

    Baumberger, T.; Lilley, M. D.; Pedersen, R. B.; Thorseth, I. H.

    2013-12-01

    Carbon dioxide capture and storage (CCS) is seen as a new possible technique for reducing the emission of industrial CO2 to the atmosphere. To evaluate the risks of sub-seabed CO2 storage, the European Commission is supporting the international and multi-disciplinary ECO2 project. Among other objectives, this project is dealing with evaluating the likelihood of leakage and the resulting possible impacts on marine ecosystems. In the framework of the ECO2 project, the release and dispersal of CO2 have been studied at several natural seep sites. In this study, we present geochemical data collected at the natural CO2 leakage analogue, Jan Mayen vent fields (JMVF). The basalt-hosted JMVF are located at 71° N on the southern end of the ultra-slow spreading Mohns Ridge, which is part of the Arctic Mid-Ocean Ridge (AMOR) system. The JMVF are composed of several venting sites, spread over a large area. These venting areas include focused high-temperature venting and diffuse low-temperature fluid flow vents as well as areas where free gas bubbles are released. Over the past few years, we have repeatedly visited and extensively sampled these vent fields to study the release and fate of CO2 in this natural seep area. One of our main objectives was to constrain the CO2 content of the widely emitted gas and to study its dispersion and fate in the water column. We have also investigated hydrate formation, which is observed at various locations. The venting fluids are chemically characterized by CO2 concentrations of up to 110 mmol/kg, having an associated isotopic composition representing a mantle carbon source. Thus, the CO2 concentrations measured at the JMVF represent the high-end compared to the concentration range of most other basalt-hosted hydrothermal mid-ocean ridge systems. Even though the concentrations of the emitted CO2 vary over time and with the type of venting (focused flow, diffuse flow or bubbles), the overall release is continuously high. The dispersion of the

  13. Multi-Satellite Characterization of Interannual Variation in Primary Production and Air-Sea CO2 Flux in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Arrigo, K. R.

    2005-12-01

    The Ross Sea is the most productive sector of the Southern Ocean, the largest of the three iron limited HNLC regions. This productivity supports a rich upper trophic level community, including large numbers of penguins, seals, and whales. It also represents a large sink for atmospheric CO2. Since the advent of ocean color remote sensing using satellites such as CZCS, SeaWiFS, and MODIS, it has become increasingly clear that productivity in the Ross Sea is also characterized by a great deal of interannual variability. Passive microwave data from the Special Sensor Microwave/Imager show that distributions of sea ice within the Ross Sea vary markedly from year to year, with some years experiencing nearly ice-free springtime conditions while others remain nearly ice covered. This extreme variability in sea ice cover is due to changes in climate state as well as some unusual events specific to the Ross Sea, such as the calving of two enormous icebergs, one in 2000 and the other in 2002. Variation in ice cover during austral spring and summer impacts the growth of the phytoplankton community, whose cumulative rate of annual primary production ranges widely, from <10 Tg C in 2002-03 to almost 40 Tg C in 1999-00. When these satellite data are used in conjunction with a three-dimensional ocean ecosystem model of the Ross Sea, the calculated air-sea fluxes of CO2 are even more variable, varying over 50-fold between 1997 and 2004. Not surprisingly, the lowest atmospheric flux of CO2 into the surface waters of the Ross Sea (0.10 Tg C) is associated with the year having the lowest primary production and highest sea ice cover. The extreme sensitivity of rates of primary production and particularly air-sea CO2 fluxes to changes in sea ice distribution in the Southern Ocean suggest that this region may undergo dramatic changes if global temperatures continue to rise, as they have in the vicinity of the Antarctic Peninsula.

  14. Structural and biophysical characterization of the α-carbonic anhydrase from the gammaproteobacterium Thiomicrospira crunogena XCL-2: insights into engineering thermostable enzymes for CO2 sequestration

    PubMed Central

    Díaz-Torres, Natalia A.; Mahon, Brian P.; Boone, Christopher D.; Pinard, Melissa A.; Tu, Chingkuang; Ng, Robert; Agbandje-McKenna, Mavis; Silverman, David; Scott, Kathleen; McKenna, Robert

    2015-01-01

    Biocatalytic CO2 sequestration to reduce greenhouse-gas emissions from industrial processes is an active area of research. Carbonic anhydrases (CAs) are attractive enzymes for this process. However, the most active CAs display limited thermal and pH stability, making them less than ideal. As a result, there is an ongoing effort to engineer and/or find a thermostable CA to fulfill these needs. Here, the kinetic and thermal characterization is presented of an α-CA recently discovered in the mesophilic hydrothermal vent-isolate extremophile Thiomicrospira crunogena XCL-2 (TcruCA), which has a significantly higher thermostability compared with human CA II (melting temperature of 71.9°C versus 59.5°C, respectively) but with a tenfold decrease in the catalytic efficiency. The X-ray crystallographic structure of the dimeric TcruCA shows that it has a highly conserved yet compact structure compared with other α-CAs. In addition, TcruCA contains an intramolecular disulfide bond that stabilizes the enzyme. These features are thought to contribute significantly to the thermostability and pH stability of the enzyme and may be exploited to engineer α-CAs for applications in industrial CO2 sequestration. PMID:26249355

  15. Structural and biophysical characterization of the α-carbonic anhydrase from the gammaproteobacterium Thiomicrospira crunogena XCL-2: insights into engineering thermostable enzymes for CO2 sequestration.

    PubMed

    Díaz-Torres, Natalia A; Mahon, Brian P; Boone, Christopher D; Pinard, Melissa A; Tu, Chingkuang; Ng, Robert; Agbandje-McKenna, Mavis; Silverman, David; Scott, Kathleen; McKenna, Robert

    2015-08-01

    Biocatalytic CO2 sequestration to reduce greenhouse-gas emissions from industrial processes is an active area of research. Carbonic anhydrases (CAs) are attractive enzymes for this process. However, the most active CAs display limited thermal and pH stability, making them less than ideal. As a result, there is an ongoing effort to engineer and/or find a thermostable CA to fulfill these needs. Here, the kinetic and thermal characterization is presented of an α-CA recently discovered in the mesophilic hydrothermal vent-isolate extremophile Thiomicrospira crunogena XCL-2 (TcruCA), which has a significantly higher thermostability compared with human CA II (melting temperature of 71.9°C versus 59.5°C, respectively) but with a tenfold decrease in the catalytic efficiency. The X-ray crystallographic structure of the dimeric TcruCA shows that it has a highly conserved yet compact structure compared with other α-CAs. In addition, TcruCA contains an intramolecular disulfide bond that stabilizes the enzyme. These features are thought to contribute significantly to the thermostability and pH stability of the enzyme and may be exploited to engineer α-CAs for applications in industrial CO2 sequestration.

  16. Emissions of NH3, CO2 and H2S during swine wastewater management: Characterization of transient emissions after air-liquid interface disturbances

    NASA Astrophysics Data System (ADS)

    Blanes-Vidal, V.; Guàrdia, M.; Dai, X. R.; Nadimi, E. S.

    2012-07-01

    Air contaminants emitted from stored animal wastewater affect human health and the environment. Measurements of gaseous emissions from undisturbed animal wastewater are abundant in the literature. However, in-barn wastewater management is characterized by the frequent occurrence of surface liquid disturbances. Information about emissions during and after wastewater disturbances is scarce. This study evaluates emissions of NH3, CO2 and H2S under transient conditions after wastewater disturbances (caused by slurry addition, water addition and mixing), and describes the mechanisms involved until reaching steady-state conditions. All three disturbances modified the gas emission patterns. Emissions of NH3 immediately decreased after the disturbances (-61% after slurry and water addition and by -91% after mixing), and then gradually increased during 90-200 min. Emissions of CO2 increased during the disturbances (40% during slurry and water addition and 1515% during mixing), and then decreased during up to 30 min after the disturbance. H2S emissions sharply increased during all three disturbances and then decreased for 2 min to 20 min. Emissions under transient conditions were related to the formation of a pH profile. Transient emissions should be considered in gas emission studies as they may represent an important part of the cumulative gas emissions during slurry storage.

  17. Characterization of mid-infrared emissions from C2H2, CO, CO2, and HCN-filled hollow fiber lasers

    NASA Astrophysics Data System (ADS)

    Jones, A. M.; Fourcade-Dutin, C.; Mao, C.; Baumgart, B.; Nampoothiri, A. V. V.; Campbell, N.; Wang, Y.; Benabid, F.; Rudolph, W.; Washburn, B. R.; Corwin, K. L.

    2012-02-01

    We have now demonstrated and characterized gas-filled hollow-core fiber lasers based on population inversion from acetylene (12C2H2) and HCN gas contained within the core of a kagome-structured hollow-core photonic crystal fiber. The gases are optically pumped via first order rotational-vibrational overtones near 1.5 μm using 1-ns pulses from an optical parametric amplifier. Transitions from the pumped overtone modes to fundamental C-H stretching modes in both molecules create narrow-band laser emissions near 3 μm. High gain resulting from tight confinement of the pump and laser light together with the active gas permits us to operate these lasers in a single pass configuration, without the use of any external resonator structure. A delay between the emitted laser pulse and the incident pump pulse has been observed and is shown to vary with pump pulse energy and gas pressure. Furthermore, we have demonstrated lasing beyond 4 μm from CO and CO2 using silver-coated glass capillaries, since fused silica based fibers do not transmit in this spectral region and chalcogenide fibers are not yet readily available. Studies of the laser pulse energy as functions of the pump pulse energy and gas pressure were performed. Efficiencies reaching ~ 20% are observed for both acetylene and CO2.

  18. CO2 laser resurfacing.

    PubMed

    Fitzpatrick, R E

    2001-07-01

    The CO2 Laser offers a variety of unique features in resurfacing facial photodamage and acne scarring. These include hemostasis, efficient removal of the epidermis in a single pass, thermally induced tissue tightening, and safe, predictable tissue interaction. Knowledge of these mechanisms will result in the capability of using the CO2 laser effectively and safely whether the goal is superficial or deep treatment.

  19. CO2 blood test

    MedlinePlus

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum ... Many medicines can interfere with blood test results. Your health care provider will tell you if you need to stop taking any medicines before you have this test. DO ...

  20. Impact of Rock Bolts on Seepage

    SciTech Connect

    F. C. Ahlers

    2001-06-01

    Characterization of seepage into drifts in unsaturated fractured tuff is a key factor for assessing the long-term viability of the proposed high level nuclear waste repository at Yucca Mountain. Rock bolts are among the methods proposed for ground control in the emplacement drifts. They may provide a conduit whereby percolating water that would otherwise bypass the drift will seep into the drift. The objective of this study is to assess the impact that the use of rock bolts may have on seepage. The impact of rock bolts on seepage is studied using a numerical model that is finely discretized around the rock bolt. There are several sources of uncertainty and variability with respect to the flow system around the drift and rock bolt. There is uncertainty about the capillary strength of the fractures around the drift. There is also uncertainty about how the permeability and capillary strength of the grout used to cement the steel rock bolts into the bolt holes will change over time. There is variability expected in the percolation rates incident upon the drifts depending on location. The uncertainty and variability of these parameters are approached by evaluating the rock bolt impact over a range of values for several model parameters. It is also important to consider where the last fracture capable of carrying flow away from the rock bolt intersects the rock bolt. Three models are used where the last fracture is 0, 10 and 50 cm above the drift.

  1. Outsourcing CO2 Emissions

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; Caldeira, K. G.

    2009-12-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

  2. Facile hydrothermal synthesis and characterization of Co2GeO4/r-GO@C ternary nanocomposite as negative electrode for Li-ion batteries.

    PubMed

    Subramanian, Yuvaraj; Kaliyappan, Karthikeyan; Ramakrishnan, Kalai Selvan

    2017-03-02

    Ternary nanocomposite of Co2GeO4/r-GO@C is synthesized by single step hydrothermal method followed by calcination. The XRD analysis reveals the formation of cubic structured Co2GeO4 and their corresponding functional groups identified through Raman analysis. The TEM analysis assures that uniform distribution of Co2GeO4 nanoparticles on the r-GO layers. The Galvanostatic charge-discharge (GCD) curve demonstrates that the initial discharge capacity of pristine Co2GeO4, Co2GeO4/r-GO and Co2GeO4/r-GO@C composite is 1400, 1284 and 1594mAhg(-1) at 50mAg(-1), respectively. The cycling stability curve shows the specific capacity of 609, 970 and 1180mAhg(-1) for pristine, Co2GeO4/r-GO and Co2GeO4/r-GO@C composite, respectively over 15 cycles. The ternary composite of Co2GeO4/r-GO@C delivers the discharge capacity of 323mAhg(-1) at high current density of 1Ag(-1) over 500 cycles with capacity retention of 71%. The rate capability curve indicates that Co2GeO4/r-GO@C composite shows the better rate capability.

  3. Geochemical characterization of tarballs on beaches along the California coast. Part I - Shallow seepage impacting the Santa Barbara Channel Islands, Santa Cruz, Santa Rosa and San Miguel

    USGS Publications Warehouse

    Hostettler, F.D.; Rosenbauer, R.J.; Lorenson, T.D.; Dougherty, J.

    2004-01-01

    Tarballs are common along the southern California coastline. This study investigates tarballs from beaches along this coastline, with a focus on Santa Cruz, Santa Rosa, and San Miquel Islands in the Santa Barbara Channel. The tarballs were fingerprinted using biomarker and stable carbon isotope parameters, and then grouped according to genetic similarities. The data show that the tarballs are of natural and not anthropogenic origin and that all originate from source rock within the Miocene Monterey Formation via shallow seeps offshore. Sterane biomarker parameters were found to vary widely in the sample set. Biodegradation, especially of the regular steranes, is the primary process impacting the biomarker distributions in a large group of samples. The most common tarball occurrences appear to come from offshore seepage near the west end of Santa Cruz Island. Another major group most likely was transported north from near Santa Monica Bay. Several individual occurrences of some of these tarball groups also were found on beaches as far north as Pt. Reyes and as far south as San Diego, indicating significant long-distance dispersal by ocean currents. This study begins a library of tarball fingerprints to be used as a database to help distinguish between natural and anthropogenic tar occurrences all along the California coast, and to compare shallow seepage with future samples of deeper production oils from the same area.

  4. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales, Class III

    SciTech Connect

    Perri, Pasquale R.

    2001-04-04

    This report describes the evaluation, design, and implementation of a DOE funded CO2 pilot project in the Lost Hills Field, Kern County, California. The pilot consists of four inverted (injector-centered) 5-spot patterns covering approximately 10 acres, and is located in a portion of the field, which has been under waterflood since early 1992. The target reservoir for the CO2 pilot is the Belridge Diatomite. The pilot location was selected based on geology, reservoir quality and reservoir performance during the waterflood. A CO2 pilot was chosen, rather than full-field implementation, to investigate uncertainties associated with CO2 utilization rate and premature CO2 breakthrough, and overall uncertainty in the unproven CO2 flood process in the San Joaquin Valley.

  5. Geochronology, geochemistry, and tectonic characterization of Quaternary large-volume travertine deposits in the southwestern United States and their implications for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Priewisch, Alexandra

    Travertines are freshwater carbonates that precipitate from carbonic groundwater due to the degassing of CO2. Travertine deposits are often situated along faults that serve as conduits for CO2-charged groundwater and their geochemistry often records mixing of deeply-derived fluids and volatiles with shallow meteoric water. Travertines are surface expressions of dynamic mantle processes related to the tectonic setting. This dissertation includes four chapters that focus on different aspects of travertine formation and their scientific value. They are excellent, although underestimated, diagnostic tools for climatology, hydrology, tectonics, geochemistry, geomicrobiology, and they can inform carbon sequestration models. Quaternary large-volume travertine deposits in New Mexico and Arizona occur in an extensional tectonic stress regime on the southeastern Colorado Plateau and along the Rio Grande rift. They accumulated above fault systems during episodes of high hydraulic head in confined aquifers, increased regional volcanic activity, and high input of mantle-derived volatiles such as CO 2 and He. Stable isotope and trace element geochemistry of travertines is controlled by groundwater geochemistry as well as the degassing of CO 2. The geochemical composition allows for distinguishing different travertine facies and evaluating past groundwater flow. The travertine deposits in New Mexico are interpreted to be extinct CO2 fields due to the large volumes that accumulated and in analogy to the travertine deposits in Arizona that are associated with an active CO2-gas field. Travertines are natural analogues for CO2 leakage along fault systems that bypassed regional cap rocks and they provide important insight into the migration of CO2 from a reservoir to the surface. The volume of travertine can be used to infer the integrated CO2 leakage along a fault system over geologic time. This leakage is estimated as: (1) CO2 that becomes fixed in CaCO3/travertine (tons of carbon

  6. Abstraction of Seepage into Drifts

    SciTech Connect

    M.L. Wilson; C.K. Ho

    2000-09-26

    A total-system performance assessment (TSPA) for a potential nuclear-waste repository requires an estimate of the amount of water that might contact waste. This paper describes the model used for part of that estimation in a recent TSPA for the Yucca Mountain site. The discussion is limited to estimation of how much water might enter emplacement drifts; additional considerations related to flow within the drifts, and how much water might actually contact waste, are not addressed here. The unsaturated zone at Yucca Mountain is being considered for the potential repository, and a drift opening in unsaturated rock tends to act as a capillary barrier and divert much of the percolating water around it. For TSPA, the important questions regarding seepage are how many waste packages might be subjected to water flow and how much flow those packages might see. Because of heterogeneity of the rock and uncertainty about the future (how the climate will evolve, etc.), it is not possible to predict seepage amounts or locations with certainty. Thus, seepage is treated as a stochastic quantity in TSPA simulations, with the magnitude and spatial distribution of seepage sampled from uncertainty distributions. The distillation of the essential components of process modeling into a form suitable for use in TSPA simulations is referred to as abstraction. In the following sections, seepage process models and abstractions will be summarized and then some illustrative results are presented.

  7. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Czirr, K.L.; Gaddis, M.P.; Moshell, M.K.

    2002-02-21

    The principle objective of this project is to demonstrate the economic viability and widespread applicability of an innovative reservoir management and carbon dioxide (CO2) flood project development approach for improving CO2 flood project economics in shallow shelf carbonate (SSC) reservoirs.

  8. Joint NASA-ESA-DARA Study. Part three: characterization of sleep under ambient CO2-levels of 0.7% and 1.2%.

    PubMed

    Gundel, A; Parisi, R A; Strobel, R; Weihrauch, M R

    1998-05-01

    An experiment was conducted to study sleep quality and sleep architecture in volunteers living in a closed system under elevated ambient CO2 levels of 0.7% and 1.2%. In a closed system, human life is possible only if the CO2 level is permanently adjusted. For the Russian space station MIR, for example, the CO2 levels of the present study are actual upper limits for the adjustment. Sleep architecture was found to be altered in astronauts on the orbiting MIR station. Sleep quantity and quality were reduced. The latency to the first REM sleep was shorter in space and slow wave sleep was redistributed from the first to the second sleep cycle. The elevated CO2 concentration in the atmosphere on MIR may be one of the reasons for those observations regarding sleep in space. Thus, this experiment was also conducted in order to clarify the interpretation of data obtained from astronauts on MIR. In this study sleep polygraphies could be recorded in 4 subjects who lived for 23 d under 0.7% and then for the same period of time under 1.2% CO2. Findings suggest that these levels of ambient CO2 do not reduce sleep quality. Sleep architecture, however, was slightly changed and showed that the amount of slow wave sleep increased with the duration of the exposure to CO2. But it can be excluded that findings on MIR were caused by elevated CO2-levels.

  9. H-Area Seepage Basins

    SciTech Connect

    Stejskal, G.

    1990-12-01

    During the third quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium.

  10. Synthesis and characterization of a novel semi-IPN hydrogel based on Salecan and poly(N,N-dimethylacrylamide-co-2-hydroxyethyl methacrylate).

    PubMed

    Hu, Xinyu; Feng, Liandong; Wei, Wei; Xie, Aming; Wang, Shiming; Zhang, Jianfa; Dong, Wei

    2014-05-25

    Salecan is a novel water-soluble, high molecular mass extracellular β-glucan produced by Agrobacterium sp. ZX09. Salecan has excellent physicochemical and biological properties, making it very suitable for hydrogel preparation. In this study, a series of novel semi-interpenetrating polymer network (semi-IPN) hydrogels containing Salecan and poly(N,N-dimethylacrylamide-co-2-hydroxyethylmethacrylate) (poly(DMAA-co-HEMA)) were synthesized by radical polymerization and semi-IPN technology. Structure and morphology of the hydrogels were characterized by FTIR, XRD, TGA and SEM. The semi-IPNs had a well-interconnected porous structure with tunable pore size ranging from 6 to 41μm. Swelling capability of the hydrogels was improved by introducing the hydrophilic Salecan. Rheological results indicated that the incorporation of poly(DMAA-co-HEMA) into hydrogels enhanced the storage modulus. Compression tests revealed that these semi-IPNs were robust materials with compressive modulus between 13.3 and 90.5kPa, the addition of Salecan increased the fracture strain from 71.1% to 88.8%. Degradation and cytotoxicity tests demonstrated that semi-IPNs were degradable and non-toxic.

  11. Do the rich always become richer? Characterizing the leaf physiological response of the high-yielding rice cultivar Takanari to free-air CO2 enrichment.

    PubMed

    Chen, Charles P; Sakai, Hidemitsu; Tokida, Takeshi; Usui, Yasuhiro; Nakamura, Hirofumi; Hasegawa, Toshihiro

    2014-02-01

    The development of crops which are well suited to growth under future environmental conditions such as higher atmospheric CO2 concentrations ([CO2]) is essential to meeting the challenge of ensuring food security in the face of the growing human population and changing climate. A high-yielding indica rice variety (Oryza sativa L. cv. Takanari) has been recently identified as a potential candidate for such breeding, due to its high productivity in present [CO2]. To test if it could further increase its productivity under elevated [CO2] (eCO2), Takanari was grown in the paddy field under season-long free-air CO2 enrichment (FACE, approximately 200 µmol mol(-1) above ambient [CO2]) and its leaf physiology was compared with the representative japonica variety 'Koshihikari'. Takanari showed consistently higher midday photosynthesis and stomatal conductance than Koshihikari under both ambient and FACE growth conditions over 2 years. Maximum ribulose-1,5-bisphosphate carboxylation and electron transport rates were higher for Takanari at the mid-grain filling stage in both years. Mesophyll conductance was higher in Takanari than in Koshihikari at the late grain-filling stage. In contrast to Koshihikari, Takanari grown under FACE conditions showed no decrease in total leaf nitrogen on an area basis relative to ambient-grown plants. Chl content was higher in Takanari than in Koshihikari at the same leaf nitrogen level. These results indicate that Takanari maintains its superiority over Koshihikari in regards to its leaf-level productivity when grown in elevated [CO2] and it may be a valuable resource for rice breeding programs which seek to increase crop productivity under current and future [CO2].

  12. Reactivity of cyclopentadienyl transition metal(ii) complexes with borate ligands: structural characterization of the toluene-activated molybdenum complex [Cp*Mo(CO)2(η(3)-CH2C6H5)].

    PubMed

    Ramalakshmi, Rongala; Maheswari, K; Sharmila, Dudekula; Paul, Anamika; Roisnel, Thierry; Halet, Jean-François; Ghosh, Sundargopal

    2016-10-18

    Reactions of cyclopentadienyl transition-metal halide complexes [Cp*Mo(CO)3Cl], 1, and [CpFe(CO)2I], 2, (Cp = C5H5; Cp* = η(5)-C5Me5) with borate ligands are reported. Treatment of 1 with [NaBt2] (Bt2 = dihydrobis(2-mercapto-benzothiazolyl)borate) in toluene yielded [Cp*Mo(CO)2(C7H4S2N)], 3, and [Cp*Mo(CO)2(η(3)-CH2C6H5)], 4, with a selective binding of toluene through C-H activation followed by orthometallation. Note that compound 4 is a structurally characterized toluene-activated molecule in which the metal is in η(3)-coordination mode. Under similar reaction conditions, [NaPy2] (Py2 = dihydrobis(2-mercaptopyridyl)borate) produced only the mercaptopyridyl molybdenum complex [Cp*Mo(CO)2(C5H4SN)], 5, in good yield. On the other hand, when compound 2 was treated individually with [NaBt] (Bt = trihydro(2-mercapto-benzothiazolyl)borate) and [NaPy2] in THF, formation of the η(1)-coordinated complexes [CpFe(CO)2(C7H4S2N)], 6, and [CpFe(CO)2(C5H4SN)], 7, was observed. The solid-state molecular structures of compounds 3, 4, 6, and 7 have been established by single-crystal X-ray crystallographic analyses.

  13. CO2-neutral fuels

    NASA Astrophysics Data System (ADS)

    Goede, A. P. H.

    2015-08-01

    The need for storage of renewable energy (RE) generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G) scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel cycle is

  14. Methane Seepage at Hyperalkaline Springs in the Ronda Peridotite Massif (Spain)

    NASA Astrophysics Data System (ADS)

    Etiope, G.; Vadillo, I.; Whiticar, M. J.; Marques, J. M.; Carreira, P. M.; Tiago, I.; Benavente, J.; Jimenez, P.; Urresti, B.

    2014-12-01

    Methane-rich, hyperalkaline spring waters and bubbling pools have been sampled in the Ronda peridotite massif in southern Spain. Water chemistry (T: 17.1-21.5 ºC; pH: 10.7-11.7; DO: <2 mg/L; Ca-OH facies) is characteristic of present-day serpentinization. Dissolved CH4 concentrations range from 0.1 to 3.2 mg/L. CH4 stable C and H isotope ratios suggest a dominant abiotic origin in two natural spring sites (delta13C: -13 to -29 ‰ VPDB; delta2H: -309 to -333 ‰ VSMOW) and a mixed biotic-abiotic origin in springs with artificial water delivery systems (i.e., pipes or fountains; delta13C: -44 to -69 ‰; delta2H: -180 to -319 ‰). At the natural springs, gas is mainly released through bubbles close to the water outlet (CH4 flux ~1 kg/day by individual bubble trains), and subordinately by microseepage from the ground, even at distances of ~100 m from the bubble-spring site (flux of 10's, up to 97, mg CH4 m-2day-1). Gas seepage is strictly controlled by faults. Under-saturation of CH4 in water, bubbling and seepage location suggest that CH4 is not exclusively transported to the surface by hyperalkaline water, but it follows autonomous migration pathways along faults. Similar 'dry' seepage of abiotic gas was observed in the Philippines, New Zealand, Turkey and Italy. Like other land-based serpentinization systems, the Ronda peridotite massif is characterized by low heat flow (<40 mW/m2), with temperatures <60°C at depths of 1.5 km. At these low T and high pH conditions, CO32- is the only available carbon source dissolved in the water, and unlikely contributes to catalysed Fischer-Tropsch Type reactions. Methane production from CO2 hydrogenation in a gas phase system (unsaturated fractured rocks) cannot be excluded. The presence of ruthenium-enriched chromitites in the Ronda peridotites may support the hypothesis that CH4 is produced by CO2 hydrogenation catalyzed by Ru minerals, even at temperatures below 100°C, as demonstrated in recent laboratory experiments

  15. Characterization of the CO2 fluid adsorption in coal as a function of pressure using neutron scattering techniques (SANS and USANS)

    USGS Publications Warehouse

    Melnichenko, Y.B.; Radlinski, A.P.; Mastalerz, Maria; Cheng, G.; Rupp, J.

    2009-01-01

    Small angle neutron scattering techniques have been applied to investigate the phase behavior of CO2 injected into coal and possible changes in the coal pore structure that may result from this injection. Three coals were selected for this study: the Seelyville coal from the Illinois Basin (Ro = 0.53%), Baralaba coal from the Bowen Basin (Ro = 0.67%), and Bulli 4 coal from the Sydney Basin (Ro = 1.42%). The coals were selected from different depths to represent the range of the underground CO2 conditions (from subcritical to supercritical) which may be realized in the deep subsurface environment. The experiments were conducted in a high pressure cell and CO2 was injected under a range of pressure conditions, including those corresponding to in-situ hydrostatic subsurface conditions for each coal. Our experiments indicate that the porous matrix of all coals remains essentially unchanged after exposure to CO2 at pressures up to 200??bar (1??bar = 105??Pa). Each coal responds differently to the CO2 exposure and this response appears to be different in pores of various sizes within the same coal. For the Seelyville coal at reservoir conditions (16????C, 50??bar), CO2 condenses from a gas into liquid, which leads to increased average fluid density in the pores (??pore) with sizes (r) 1 ?? 105 ??? r ??? 1 ?? 104???? (??pore ??? 0.489??g/cm3) as well as in small pores with size between 30 and 300???? (??pore ??? 0.671??g/cm3). These values are by a factor of three to four higher than the density of bulk CO2 (??CO2) under similar thermodynamic conditions (??CO2 ??? 0.15??g/cm3). At the same time, in the intermediate size pores with r ??? 1000???? the average fluid density is similar to the density of bulk fluid, which indicates that adsorption does not occur in these pores. At in situ conditions for the Baralaba coal (35 OC, 100??bar), the average fluid density of CO2 in all pores is lower than that of the bulk fluid (??pore / ??CO2 ??? 0.6). Neutron scattering from the

  16. Widespread Low-Latitude Diurnal CO2 Frost on Mars

    NASA Astrophysics Data System (ADS)

    Piqueux, S.; Kleinböhl, A.; Hayne, P. O.; Heavens, N. G.; Kass, D. M.; McCleese, D. J.; Schofield, J. T.; Shirley, J. H.

    2016-09-01

    We map and characterize MCS nighttime surface temperature observations consistent with the occurrence of CO2 frost on Mars. Low-latitude nighttime CO2 frost is widespread, with potential implications for the physical nature of the surface layer.

  17. Assessing the health risks of natural CO2 seeps in Italy

    PubMed Central

    Roberts, Jennifer J.; Wood, Rachel A.; Haszeldine, R. Stuart

    2011-01-01

    Industrialized societies which continue to use fossil fuel energy sources are considering adoption of Carbon Capture and Storage (CCS) technology to meet carbon emission reduction targets. Deep geological storage of CO2 onshore faces opposition regarding potential health effects of CO2 leakage from storage sites. There is no experience of commercial scale CCS with which to verify predicted risks of engineered storage failure. Studying risk from natural CO2 seeps can guide assessment of potential health risks from leaking onshore CO2 stores. Italy and Sicily are regions of intense natural CO2 degassing from surface seeps. These seeps exhibit a variety of expressions, characteristics (e.g., temperature/flux), and location environments. Here we quantify historical fatalities from CO2 poisoning using a database of 286 natural CO2 seeps in Italy and Sicily. We find that risk of human death is strongly influenced by seep surface expression, local conditions (e.g., topography and wind speed), CO2 flux, and human behavior. Risk of accidental human death from these CO2 seeps is calculated to be 10-8 year-1 to the exposed population. This value is significantly lower than that of many socially accepted risks. Seepage from future storage sites is modeled to be less that Italian natural flux rates. With appropriate hazard management, health risks from unplanned seepage at onshore storage sites can be adequately minimized. PMID:21911398

  18. Assessing the health risks of natural CO2 seeps in Italy

    SciTech Connect

    Roberts, J.J.; Wood, R.A.; Haszeldine, R.S.

    2011-10-04

    Industrialized societies which continue to use fossil fuel energy sources are considering adoption of Carbon Capture and Storage (CCS) technology to meet carbon emission reduction targets. Deep geological storage of CO2 onshore faces opposition regarding potential health effects of CO2 leakage from storage sites. There is no experience of commercial scale CCS with which to verify predicted risks of engineered storage failure. Studying risk from natural CO2 seeps can guide assessment of potential health risks from leaking onshore CO2 stores. Italy and Sicily are regions of intense natural CO2 degassing from surface seeps. These seeps exhibit a variety of expressions, characteristics (e.g., temperature/ flux), and location environments. Here we quantify historical fatalities from CO2 poisoning using a database of 286 natural CO2 seeps in Italy and Sicily. We find that risk of human death is strongly influenced by seep surface expression, local conditions (e.g., topography and wind speed), CO2 flux, and human behavior. Risk of accidental human death from these CO2 seeps is calculated to be 10-8 year-1 to the exposed population. This value is significantly lower than that of many socially accepted risks. Seepage from future storage sites is modeled to be less than Italian natural flux rates. With appropriate hazard management, health risks from unplanned seepage at onshore storage sites can be adequately minimized.

  19. Assessing the health risks of natural CO2 seeps in Italy

    NASA Astrophysics Data System (ADS)

    Roberts, Jennifer J.; Wood, Rachel A.; Haszeldine, R. Stuart

    2011-10-01

    Industrialized societies which continue to use fossil fuel energy sources are considering adoption of Carbon Capture and Storage (CCS) technology to meet carbon emission reduction targets. Deep geological storage of CO2 onshore faces opposition regarding potential health effects of CO2 leakage from storage sites. There is no experience of commercial scale CCS with which to verify predicted risks of engineered storage failure. Studying risk from natural CO2 seeps can guide assessment of potential health risks from leaking onshore CO2 stores. Italy and Sicily are regions of intense natural CO2 degassing from surface seeps. These seeps exhibit a variety of expressions, characteristics (e.g., temperature/flux), and location environments. Here we quantify historical fatalities from CO2 poisoning using a database of 286 natural CO2 seeps in Italy and Sicily. We find that risk of human death is strongly influenced by seep surface expression, local conditions (e.g., topography and wind speed), CO2 flux, and human behavior. Risk of accidental human death from these CO2 seeps is calculated to be 10-8 year-1 to the exposed population. This value is significantly lower than that of many socially accepted risks. Seepage from future storage sites is modeled to be less that Italian natural flux rates. With appropriate hazard management, health risks from unplanned seepage at onshore storage sites can be adequately minimized.

  20. Lake Okeechobee seepage monitoring network

    USGS Publications Warehouse

    McKenzie, Donald J.

    1973-01-01

    This report summarizes the data collected at the five original monitoring sites along the south shore of Lake Okeechobee from January 29, 1970 to June 28, 1972. In order to use the hydrographs in this report to full advantage, they should be studied in conjunction with Meyer's graphs and text (1971). During steady-state conditions, water seeps from the lake through the filtercake and through the aquifers beneath the dike. At those sites where the filtercake is missing, or has about the same permeability as the aquifers, the seepage from the lake is about equivalent to the flow through the aquifers. Present data are insufficient to determine whether or not filtercake buildup has reduced seepage. No appreciable change in drainage occurred during the observed period.

  1. Hydrogeochemistry of Maine seepage lakes and related groundwaters

    NASA Astrophysics Data System (ADS)

    Stauffer, Robert E.; Wittchen, Bruce D.

    1992-10-01

    Southeastern Maine contains numerous small seepage lakes (no perennial surface inflows or outflows), set in felsic, glacial deposits (eskers, pitted outwash, glacio-marine deltaic terraces) dating from the Wisconsin glacial retreat ca. 12 500 years B.P. The modern landscape is either forested or maintained as low blueberry heath by semi-annual mowing and burning. Although local precipitation is currently moderately acidic (volume-weighted pH ≈ 4.5), spring waters issuing from the glacial deposits are only weakly acidic (6.1 < pH < 7.0), and bicarbonate-buffered (120 to 300 mmol m -3) on account of tertiary weathering by dissolved CO 2. The order of mobility (denudation rate) for base cations (BC) is: Ca > Na > Mg > K, the same as for upland granitic terrane in the same region. Springwater composition is temporally stable but geographically variable. The most dilute springwaters drain blueberry barrens. Here, chemical weathering is limited by available acidity as evidenced by the relatively high final pHs (> 6.3) and low concentrations of strong oxy-anions (nitrate, sulfate) and dissolved inorganic carbon (DIC < 250 μM). Closely neighboring lakes often range widely in alkalinity, BC, and F, depending on their connection to the local groundwater system. Tracer analysis indicates seepage inflow is equal to 5-50 cm year -1 for typical regional seepage lakes, vs. higher rates (> 100 cm year -1) for groundwater discharge lakes. Approximately 88% of Si inputs to regional seepage lakes is retained in the sediments. Non-marine sulfate is lowest in groundwater discharge lakes containing the highest concentrations of BC and F, and featuring the shortest hydraulic residence times, suggesting that S retention in lake sediments is currently less efficient than in the adjoining terrestrial soils and vegetation.

  2. Ability of the 4-D-Var analysis of the GOSAT BESD XCO2 retrievals to characterize atmospheric CO2 at large and synoptic scales

    NASA Astrophysics Data System (ADS)

    Massart, Sébastien; Agustí-Panareda, Anna; Heymann, Jens; Buchwitz, Michael; Chevallier, Frédéric; Reuter, Maximilian; Hilker, Michael; Burrows, John P.; Deutscher, Nicholas M.; Feist, Dietrich G.; Hase, Frank; Sussmann, Ralf; Desmet, Filip; Dubey, Manvendra K.; Griffith, David W. T.; Kivi, Rigel; Petri, Christof; Schneider, Matthias; Velazco, Voltaire A.

    2016-02-01

    This study presents results from the European Centre for Medium-Range Weather Forecasts (ECMWF) carbon dioxide (CO2) analysis system where the atmospheric CO2 is controlled through the assimilation of column-averaged dry-air mole fractions of CO2 (XCO2) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free-run simulation (without assimilation of XCO2), and they are both evaluated against XCO2 data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO2 product from the Bremen Optimal Estimation Differential Optical Absorption Spectroscopy (BESD) algorithm during the year 2013 provides XCO2 fields with an improved mean absolute error of 0.6 parts per million (ppm) and an improved station-to-station bias deviation of 0.7 ppm compared to the free run (1.1 and 1.4 ppm, respectively) and an improved estimated precision of 1 ppm compared to the GOSAT BESD data (3.3 ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems, where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10-day forecast from each analysis at 00:00 UTC, and we demonstrate that the CO2 forecast shows synoptic skill for the largest-scale weather patterns (of the order of 1000 km) even up to day 5 compared to its own analysis.

  3. Ability of the 4-D-Var analysis of the GOSAT BESD XCO2 retrievals to characterize atmospheric CO2 at large and synoptic scales

    NASA Astrophysics Data System (ADS)

    Massart, S.; Agustí-Panareda, A.; Heymann, J.; Buchwitz, M.; Chevallier, F.; Reuter, M.; Hilker, M.; Burrows, J. P.; Hase, F.; Desmet, F.; Feist, D. G.; Kivi, R.

    2015-09-01

    This study presents results from the European Centre for Medium-Range Weather Forecasts (ECMWF) carbon dioxide (CO2) analysis system where the atmospheric CO2 is controlled through the assimilation of column-average dry-air mole fractions of CO2 (XCO2) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free run simulation and they are both evaluated against XCO2 data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO2 product from the Bremen Optimal Estimation DOAS (BESD) algorithm during the year 2013 provides XCO2 fields with an improved station-to-station bias deviation of 0.7 parts per million (ppm) compared to the free run (1.4 ppm) and an improved estimated precision of ~ 1 ppm compared to the used GOSAT data (3.4 ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10 day forecast from each analysis at 00:00 UTC. Compared to its own analysis the CO2 forecast shows synoptic skill for the largest scale weather patterns even up to day 5 according to the anomaly correlation coefficient.

  4. CO2 Laser Market

    NASA Astrophysics Data System (ADS)

    Simonsson, Samuel

    1989-03-01

    It gives me a great deal of pleasure to introduce our final speaker of this morning's session for two reasons: First of all, his company has been very much in the news not only in our own community but in the pages of Wall Street Journal and in the world economic press. And, secondly, we would like to welcome him to our shores. He is a temporary resident of the United States, for a few months, forsaking his home in Germany to come here and help with the start up of a new company which we believe, probably, ranks #1 as the world supplier of CO2 lasers now, through the combination of former Spectra Physics Industrial Laser Division and Rofin-Sinar GMBH. Samuel Simonsson is the Chairman of the Board of Rofin-Sinar, Inc., here in the U.S. and managing director of Rofin-Sinar GMBH. It is a pleasure to welcome him.

  5. Drift natural convection and seepage at the Yucca Mountain repository

    NASA Astrophysics Data System (ADS)

    Halecky, Nicholaus Eugene

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock, from the hot drift center to the cool drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water- induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  6. Our trial to develop a risk assessment tool for CO2 geological storage (GERAS-CO2GS)

    NASA Astrophysics Data System (ADS)

    Tanaka, A.; Sakamoto, Y.; Komai, T.

    2012-12-01

    We will introduce our researches about to develop a risk assessment tool named 'GERAS-CO2GS' (Geo-environmental Risk Assessment System, CO2 Geological Storage Risk Assessment System) for 'Carbon Dioxide Geological Storage (Geological CCS)'. It aims to facilitate understanding of size of impact of risks related with upper migration of injected CO2. For gaining public recognition about feasibility of Geological CCS, quantitative estimation of risks is essential, to let public knows the level of the risk: whether it is negligible or not. Generally, in preliminary hazard analysis procedure, potential hazards could be identified within Geological CCS's various facilities such as: reservoir, cap rock, upper layers, CO2 injection well, CO2 injection plant and CO2 transport facilities. Among them, hazard of leakage of injected C02 is crucial, because it is the clue to estimate risks around a specific injection plan in terms of safety, environmental protection effect and economy. Our risk assessment tool named GERAS-CO2GS evaluates volume and rate of retention and leakage of injected CO2 in relation with fractures and/or faults, and then it estimates impact of seepages on the surface of the earth. GERAS-CO2GS has four major processing segments: (a) calculation of CO2 retention and leakage volume and rate, (b) data processing of CO2 dispersion on the surface and ambient air, (c) risk data definition and (d) evaluation of risk. Concerning to the injection site, we defined a model, which is consisted from an injection well and a geological strata model: which involves a reservoir, a cap rock, an upper layer, faults, seabed, sea, the surface of the earth and the surface of the sea. For retention rate of each element of CO2 injection site model, we use results of our experimental and numerical studies on CO2 migration within reservoirs and faults with specific lithological conditions. For given CO2 injection rate, GERAS-CO2GS calculates CO2 retention and leakage of each segment

  7. Development and Characterization of a High Speed Mid-IR Tunable Diode Laser Absorption Spectrometer for CO and CO2 Detection in Detonation Events

    DTIC Science & Technology

    2014-03-27

    expected results with approximately 10% error bounds. With this system’s proof of concept, it will be possible to analyze real combustors as well as...the intensity is normalized ac - cording to an intensity where no absorption occurs according to Beer’s Law. Furthermore, the plots now focus on the...Data for CO (top) and CO2 (bottom) in which the intensity is normalized ac - cording to an intensity where no absorption occurs according to Beer’s

  8. Probability distribution functions of turbulence in seepage-affected alluvial channel

    NASA Astrophysics Data System (ADS)

    Sharma, Anurag; Kumar, Bimlesh

    2017-02-01

    The present experimental study is carried out on the probability distribution functions (PDFs) of turbulent flow characteristics within near-bed-surface and away-from-bed surfaces for both no seepage and seepage flow. Laboratory experiments were conducted in the plane sand bed for no seepage (NS), 10% seepage (10%S) and 15% seepage (15%) cases. The experimental calculation of the PDFs of turbulent parameters such as Reynolds shear stress, velocity fluctuations, and bursting events is compared with theoretical expression obtained by Gram-Charlier (GC)-based exponential distribution. Experimental observations follow the computed PDF distributions for both no seepage and seepage cases. Jensen-Shannon divergence (JSD) method is used to measure the similarity between theoretical and experimental PDFs. The value of JSD for PDFs of velocity fluctuation lies between 0.0005 to 0.003 while the JSD value for PDFs of Reynolds shear stress varies between 0.001 to 0.006. Even with the application of seepage, the PDF distribution of bursting events, sweeps and ejections are well characterized by the exponential distribution of the GC series, except that a slight deflection of inward and outward interactions is observed which may be due to weaker events. The value of JSD for outward and inward interactions ranges from 0.0013 to 0.032, while the JSD value for sweep and ejection events varies between 0.0001 to 0.0025. The theoretical expression for the PDF of turbulent intensity is developed in the present study, which agrees well with the experimental observations and JSD lies between 0.007 and 0.015. The work presented is potentially applicable to the probability distribution of mobile-bed sediments in seepage-affected alluvial channels typically characterized by the various turbulent parameters. The purpose of PDF estimation from experimental data is that it provides a complete numerical description in the areas of turbulent flow either at a single or finite number of points.

  9. Sensory Transduction of the CO2 Response of Guard Cells

    SciTech Connect

    Dr. Eduardo Zeiger

    2003-06-30

    Stomata have a key role in the regulation of gas exchange and intercellular CO2 concentrations of leaves. Guard cells sense internal and external signals in the leaf environment and transduce these signals into osmoregulatory processes that control stomatal apertures. This research proposal addresses the characterization of the sensory transduction of the CO2 signal in guard cells. Recent studies have shown that in Vicia leaves kept at constant light and temperature in a growth chamber, changes in ambient CO2 concentrations cause large changes in guard cell zeaxanthin that are linear with CO2-dependent changes in stomatal apertures. Research proposed here will test the hypothesis that zeaxanthin function as a transducer of CO2 signals in guard cells. Three central aspects of this hypothesis will be investigated: CO2 sensing by the carboxylation reaction of Rubisco in the guard cell chloroplast, which would modulate zeaxanthin concentrations via changes in lumen pH; transduction of the CO2 signal by zeaxanthin via a transducing cascade that controls guard cell osmoregulation; and blue light dependence of the CO2 signal transduction by zeaxanthin, required for the formation of an isomeric form of zeaxanthin that is physiologically active as a transducer. The role of Rubisco in CO2 sensing will be investigated in experiments characterizing the stomatal response to CO2 in the Arabidopsis mutants R100 and rca-, which have reduced rates of Rubisco-dependent carboxylation. The role of zeaxanthin as a CO2 transducer will be studied in npq1, a zeaxanthin-less mutant. The blue light-dependence of CO2 sensing will be studied in experiments characterizing the stomatal response to CO2 under red light. Arabidopsis mutants will also be used in further studies of an acclimation of the stomatal response to CO2, and a possible role of the xanthophyll cycle of the guard cell chloroplast in acclimations of the stomatal response to CO2. Studies on the osmoregulatory role of sucrose in

  10. Application of gas phase cryogenic vibrational spectroscopy to characterize the CO2, CO, N2 and N2O interactions with the open coordination site on a Ni(I) macrocycle using dual cryogenic ion traps

    NASA Astrophysics Data System (ADS)

    Craig, Stephanie M.; Menges, Fabian S.; Johnson, Mark A.

    2017-02-01

    Recent advances in gas phase ion chemistry, coupled with cryogenic ion vibrational predissociation spectroscopy, provide a powerful way to characterize the structures of small molecules bound to open coordination sites of organometallic compounds. Here we extend our previous measurements on the relatively weakly interacting CO2 molecule with a Ni(I) tetraaza-macrocyclic compound to enable the characterization of more strongly interacting substrates. We first confirm the calculated η2-C,O binding motif of CO2 using isotopic labeling by direct, one photon vibrational predissociation of the Ni(I)-CO2 complex. We then apply this approach to study complexation of N2 at the active site. The generality of the method is then expanded to include application to more strongly bound systems that cannot be photodissociated with one IR photon. This involves implementation of a recently developed scheme (Marsh et al., 2015) involving two temperature-controlled ion traps. The first is optimized to complex the substrate molecule to the active site and the second is cooled to around 10 K to enable condensation of weakly bound "tag" molecules onto the target complex so as to enable its characterization by linear vibrational predissociation spectroscopy. We demonstrate this capability by applying it to the coordination of CO to the active Ni(I) site, as well as to elucidate the nature of the products that are formed upon reaction with N2O.

  11. Isolation of microorganisms from CO2 sequestration sites through enrichments under high pCO2

    NASA Astrophysics Data System (ADS)

    Peet, K. C.; Freedman, A. J.; Boreham, C.; Thompson, J. R.

    2012-12-01

    Carbon Capture and Storage (CCS) in geologic formations has the potential to reduce greenhouse gas emissions from fossil fuel processing and combustion. However, little is known about the effects that CO2 may have on biological activity in deep earth environments. To understand microorganisms associated with these environments, we have developed a simple high-pressure enrichment methodology to cultivate organisms capable of growth under supercritical CO2 (scCO2). Growth media targeting different subsurface functional metabolic groups is added to sterilized 316 stainless steel tubing sealed with quarter turn plug valves values and pressurized to 120-136 atm using a helium-padded CO2 tank, followed by incubation at 37 °C to achieve the scCO2 state. Repeated passages of crushed subsurface rock samples and growth media under supercritical CO2 headspaces are assessed for growth via microscopic enumeration. We have utilized this method to survey sandstone cores for microbes capable of growth under scCO2 from two different geologic sites targeted for carbon sequestration activities. Reproducible growth of microbial biomass under high pCO2 has been sustained from each site. Cell morphologies consist of primarily 1-2 μm rods and oval spores, with densities from 1E5-1E7 cells per ml of culture. We have purified and characterized a bacterial strain most closely related to Bacillus subterraneus (99% 16S rRNA identity) capable of growth under scCO2. Preliminary physiological characterization of this strain indicates it is a spore-forming facultative anaerobe able to grow in 0.5 to 50 ppt salinity. Genome sequencing and analysis currently in progress will help reveal genetic mechanisms of acclimation to high pCO2 conditions associated with geologic carbon sequestration.

  12. Forecasting global atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Agustí-Panareda, A.; Massart, S.; Chevallier, F.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Ciais, P.; Deutscher, N. M.; Engelen, R.; Jones, L.; Kivi, R.; Paris, J.-D.; Peuch, V.-H.; Sherlock, V.; Vermeulen, A. T.; Wennberg, P. O.; Wunch, D.

    2014-11-01

    A new global atmospheric carbon dioxide (CO2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO2 analyses based on the assimilation of CO2 products retrieved from satellite measurements and

  13. Simulation procedure of unconfined seepage with an inner seepage face in a heterogeneous field

    NASA Astrophysics Data System (ADS)

    Wu, MengXi; Yang, LianZhi; Yu, Ting

    2013-06-01

    An inner seepage face phenomenon is given and a numerical simulation procedure has been developed. It may appear at the interface of two materials when an unconfined seepage flows from a porous media to a coarser porous media with a higher permeability. Inaccuracy and divergent problems may arise both in a saturated-only and in a variably saturated analysis while an inner seepage face is not simulated with a special procedure. The position of the seepage face is determined during the nonlinear iteration process and the flux of the inner seepage face nodes is transferred to the downstream side nodes. Validity and efficiency of the procedure are illustrated by the simulation of two dimensional steady state seepage examples of heterogeneous zoned dams which is usually used to validate algorithms. An analysis of a three-dimensional earth core rockfill dam is also presented here. The procedure can also be applied to general transient seepage problems.

  14. Seepage water of northern Utah

    USGS Publications Warehouse

    Fortier, Samuel

    1897-01-01

    The term “seepage water” is used by the irrigators of the West to designate the water which reaches the lowest grounds or the stream channels, swelling the latter by imperceptible degrees and keeping up the flow long after the rains have ceased and the snow has melted. The word “seepage” is applied particularly to the water which begins to appear in spots below irrigation canals and cultivated fields, usually some months or even years after irrigation has been introduced, and which tends to convert the lowlands into marshes and gives rise to springs, which in turn may be employed in watering other fields.The importance of a thorough knowledge of the behavior of seepage water is obvious when consideration is given to the close relationship which exists between the available water supply and the material prosperity of the arid region where irrigation is practiced. This is particularly true of Utah, where every readily available source of supply has long since been utilized and where the rapidly increasing agricultural population necessitates the complete utilization of all fresh waters.

  15. Estimation of continuous anthropogenic CO2: model-based evaluation of CO2, CO, δ13C(CO2) and Δ14C(CO2) tracer methods

    NASA Astrophysics Data System (ADS)

    Vardag, S. N.; Gerbig, C.; Janssens-Maenhout, G.; Levin, I.

    2015-11-01

    We investigate different methods for estimating anthropogenic CO2 using modeled continuous atmospheric concentrations of CO2 alone, as well as CO2 in combination with the surrogate tracers CO, δ13C(CO2) and Δ14C(CO2). These methods are applied at three hypothetical stations representing rural, urban and polluted conditions. We find that, independent of the tracer used, an observation-based estimate of continuous anthropogenic CO2 is not yet feasible at rural measurement sites due to the low signal-to-noise ratio of anthropogenic CO2 estimates at such settings. The tracers δ13C(CO2) and CO provide an accurate possibility to determine anthropogenic CO2 continuously, only if all CO2 sources in the catchment area are well characterized or calibrated with respect to their isotopic signature and CO to anthropogenic CO2 ratio. We test different calibration strategies for the mean isotopic signature and CO to CO2 ratio using precise Δ14C(CO2) measurements on monthly integrated as well as on grab samples. For δ13C(CO2), a calibration with annually averaged 14C(CO2) grab samples is most promising, since integrated sampling introduces large biases into anthropogenic CO2 estimates. For CO, these biases are smaller. The precision of continuous anthropogenic CO2 determination using δ13C(CO2) depends on measurement precision of δ13C(CO2) and CO2, while the CO method is mainly limited by the variation in natural CO sources and sinks. At present, continuous anthropogenic CO2 could be determined using the tracers δ13C(CO2) and/or CO with a precision of about 30 %, a mean bias of about 10 % and without significant diurnal discrepancies. Hypothetical future measurements of continuous Δ14C(CO2) with a precision of 5 ‰ are promising for anthropogenic CO2 determination (precision ca. 10-20 %) but are not yet available. The investigated tracer-based approaches open the door to improving, validating and reducing biases of highly resolved emission inventories using atmospheric

  16. Geochemical and mineralogical characterization of the Arbuckle aquifer with laboratory flow cell experiments under supercritical conditions: Implications for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Barker, R. L.; Watney, W. L.; Bhattacharya, S.; Strazisar, B. R.; Kelly, L.; Ford, S. K.; Datta, S.

    2011-12-01

    The deep saline aquifer in south-central Kansas has been proposed as a potential site for geologic storage for CO2. Two wells (KGS 1-32 and 1-28) have been drilled to the basement to provide data for a site specific determination of the storage potential of the Arbuckle. The entirety of the Arbuckle (~4100-5100 ft) was cored to provide rock samples for description and flow cell experiments. Initial examination of the formation rocks show heterogeneity throughout the core samples that makes evident the need for careful examination of the formation to ensure accurate geochemical modeling in determining the storage capacity and extent of mineralization within injection rocks. The dominant mineralogy in the proposed CO2 injection zone is dolomitic limestone with sporadic large cherty nodules. Presence of extensive vugs and micro fractures are common at some depths. Thin section and XRD data have provided the specific mineral assemblage of each core plug. Drill stem test water samples were collected from 8 depths throughout the aquifer to describe the changing chemistry of water with depth. Initial chemical analysis show a hyper saline brine (range~50,000 - 190,000 TDS) dominated by Cl, Na and Ca. Elemental ratios of Cl:Br, Na:Cl and Ca:Sr are what is expected of a typical saline aquifer system. The swabbed water from 4995 to 5020 ft gave a constant pH of 4.76 for the entire period of pumping and field results show high sulfate concentrations (>200 mg/L). Laboratory experiments carried out at the National Energy Technology Laboratory at formation temperatures and pressures using formation core plugs and collected brine to identify the major reaction that can be anticipated when supercritical CO2 is in place. Formation brine is injected into the core plugs and supercritical CO2 is added thereafter. The effluent is collected as a time series of 1, 3, 6, 12, 18, 24, 32, 48 and 72 hours and analyzed for major, trace elements and anions by ICP-OES and IC to see the chemical

  17. Geological and geophysical properties of cap rock in a natural CO2 occurrence, Mihályi-Répcelak area, Western Hungary

    NASA Astrophysics Data System (ADS)

    Király, Csilla; Szamosfalvi, Ágnes; Sendula, Eszter; Páles, Mariann; Kovács, István; Kónya, Péter; Falus, György; Szabó, Csaba

    2015-04-01

    The physical and geochemical consistency of the cap rock is primarily important for safe geological storage of CO2.. As a consequence of CO2 injection reactions took place between the minerals of the reservoir, the cap rock and CO2 saturated pore water. These reactions may change the mineral composition and petrophysical properties of the storage reservoir as well as the cap rock that provides the only physical barrier that retains carbon dioxide in the target reservoir formation. Study of the natural CO2 occurrences delivers information to understand which properties of a cap rock provide the sustainable closure and retainment. Knowledge of the long term effect of CO2 on the behavior of the cap rock is an important input in the selection procedure of a potential CO2 injection site. Yet, very few data exist on geochemical properties and reactivity of the cap rocks. During normal commercial operations the reservoir is typically cored, but not the cap rock. This study may enhance our knowledge about possible mineralogical reactions, which can occur in clayey-aleuritic cap rocks. The Mihályi-Répcelak natural CO2 occurrence is believed to be leakage safe. There is no known seepage on the surface. It is suggested that the aleuritic clay rich cap rock occurring at the natural reservoir can stop CO2 migration into other reservoirs or to the surface. The most important characteristics of cap rocks that they have low permeability (<0.1 mD) and porosity (eff.por. = 4%) and high clayeyness (approx. 80%). However, we demonstrate that in addition to these parameters the geochemical properties of cap rock is also important. In order to characterize the natural CO2 occurrence, we applied the following analysis, like XRD, FTIR, SEM. The petrophysical properties are determined from the interpretation of geophysical well-logs and grain size distribution. The most important result of this study that adequate petrophysical properties do not completely define the suitability of a cap

  18. Forecasting global atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Agustí-Panareda, A.; Massart, S.; Chevallier, F.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Ciais, P.; Deutscher, N. M.; Engelen, R.; Jones, L.; Kivi, R.; Paris, J.-D.; Peuch, V.-H.; Sherlock, V.; Vermeulen, A. T.; Wennberg, P. O.; Wunch, D.

    2014-05-01

    A new global atmospheric carbon dioxide (CO2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO2 analyses based on the assimilation of CO2 satellite retrievals, as they become available in

  19. Characterization of model-data mismatch of CO2 concentrations due to misrepresentation of mixing layer height in high resolution WRF-VPRM simulations

    NASA Astrophysics Data System (ADS)

    Kretschmer, Roberto; Gerbig, Christoph; Ahmadov, Ravan; Pillay, Dhanya K.; Karstens, Ute; Chen, Huilin

    2010-05-01

    Estimating surface-atmosphere exchange of greenhouse gases at regional scales is important for understanding feedbacks between climate and the carbon cycle, but also for verifying climate change mitigation such as emission reductions or carbon sequestration. One way to quantify greenhouse gas budgets on regional scales is to use atmospheric mixing ratio measurements in combination with high resolution inverse modeling tools. An important aspect of this top-down approach is that mismatches between observations and model results for mixing ratios are not solely due to uncertainties in surface-atmosphere exchange fluxes that are targeted by the inversion, but also due to errors in the transport models used for inverse modeling. One of the dominant uncertainties in this context is related to vertical mixing associated with turbulence near the surface, which causes trace gases to be mixed within the atmospheric mixing layer. The mixing height, up to which trace gases emitted from the surface get vertically mixed within about an hour, provides a good diagnostic to assess vertical mixing. Uncertainties of mixing heights (zi) as represented in the transport model can result in uncertainties of CO2 mixing ratios of several ppm during summertime, much larger than measurement uncertainties. The goal of our study is to systematically quantify and reduce these uncertainties in a high resolution model by using observation based estimates of zi. We make use of the WRF-VPRM modeling framework, which couples the Weather Research & Forecasting (WRF) transport model with the diagnostic biosphere Vegetation Photosynthesis and Respiration Model (VPRM) at high horizontal resolution (10 km) over Europe. To asses the influence of differences in simulated vertical mixing we set up our model with two different PBL schemes. We used a model independent method to derive the mixing layer heights from both runs for the month of August 2006 during day time. Simulated zi were also compared against

  20. Is CO2 ice permanent?

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1992-01-01

    Carbon dioxide ice has been inferred to exist at the south pole in summertime, but Earth based measurements in 1969 of water vapor in the Martian atmosphere suggest that all CO2 ice sublined from the southern polar cap and exposed underlying water ice. This implies that the observed summertime CO2 ice is of recent origin. It appears possible to construct an energy balance model that maintains seasonal CO2 ice at the south pole year round and still reasonably simulates the polar cap regression and atmospheric pressure data. This implies that the CO2 ice observed in the summertime south polar cap could be seasonal in origin, and that minor changes in climate could cause CO2 ice to completely vanish, as would appear to have happened in 1969. However, further research remains before it is certain whether the CO2 ice observed in the summertime south polar cap is seasonal or is part of a permanent reservoir.

  1. Co2 geological sequestration

    SciTech Connect

    Xu, Tianfu

    2004-11-18

    Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.

  2. Effects of dissolved CO2 on Shallow Freshwater Microbial Communities simulating a CO2 Leakage Scenario

    NASA Astrophysics Data System (ADS)

    Gulliver, D. M.; Lowry, G. V.; Gregory, K.

    2013-12-01

    Geological carbon sequestration is likely to be part of a comprehensive strategy to minimize the atmospheric release of greenhouse gasses, establishing a concern of sequestered CO2 leakage into overlying potable aquifers. Leaking CO2 may affect existing biogeochemical processes and therefore water quality. There is a critical need to understand the evolution of CO2 exposed microbial communities that influence the biogeochemistry in these freshwater aquifers. The evolution of microbial ecology for different CO2 exposure concentrations was investigated using fluid-slurry samples obtained from a shallow freshwater aquifer (55 m depth, 0.5 MPa, 22 °C, Escatawpa, MS). The microbial community of well samples upstream and downstream of CO2 injection was characterized. In addition, batch vessel experiments were conducted with the upstream aquifer samples exposed to varying pCO2 from 0% to 100% under reservoir temperature and pressure for up to 56 days. The microbial community of the in situ experiment and the batch reactor experiment were analyzed with 16S rRNA clone libraries and qPCR. In both the in situ experiment and the batch reactor experiment, DNA concentration did not correlate with CO2 exposure. Both the in situ experiment and the batch reactors displayed a changing microbial community with increased CO2 exposure. The well water isolate, Curvibacter, appeared to be the most tolerant genus to high CO2 concentrations in the in situ experiments and to mid-CO2 concentrations in the batch reactors. In batch reactors with pCO2 concentrations higher than experienced in situ (pCO2 = 0.5 MPa), Pseudomonas appeared to be the most tolerant genus. Findings provide insight into a dynamic biogeochemical system that will alter with CO2 exposure. Adapted microbial populations will eventually give rise to the community that will impact the metal mobility and water quality. Knowledge of the surviving microbial populations will enable improved models for predicting the fate of CO2

  3. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    SciTech Connect

    Fauth, D.J.; Filburn, T.P.; Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  4. Geochemical and Mineralogical Evaluation of CO2-Brine-Rock Experiments: Characterizing Porosity and Permeability Variations in the Cambrian Mount Simon Sandstone

    NASA Astrophysics Data System (ADS)

    Gonzalez, A. B.; Bowen, B. B.

    2012-12-01

    The Cambrian Mount Simon Sandstone has been targeted as a major reservoir for carbon dioxide storage in the Illinois Basin. The Mount Simon Sandstone's geologic setting, mature quartz to arkosic composition, reservoir thickness, and overlying Eau Claire Formation seal make it an attractive candidate for long-term storage potential of carbon dioxide. Injection of carbon dioxide has been shown to cause a range of chemical alterations that causes dissolution of existing minerals and precipitation of secondary phases that can alter the porosity and permeability of the reservoir. This study focuses on using detailed microscopic analysis of two compositionally and texturally different Mount Simon Sandstone samples from the Illinois Basin that were experimentally exposed to CO2-rich brines for 6 months at the NETL in collaboration with the Indiana Geological Survey. Our objective was to examine the experimental samples to determine how post-experiment mineralogical and geochemical alterations relate to porosity and permeability variations. Gazzi-Dickinson point counting of Vermillion County samples adjacent to experimental sample depths (5805 ft) show that the sample contains an average of 78% quartz, 15% feldspar, 2% lithics, and 5% porosity. Point count data of Knox County samples from 8642.5, 8542, and 8642.2 show the experimental sample has an average of 70% quartz, 22% feldspar, 4% lithics, and 3.9% porosity. Both samples were submerged in carbon dioxide-saturated brine synthesized to match the measured geochemistry of Mount Simon Sandstone pore water for six months at 24MPa and 90 degrees to replicate sequestration conditions. The results of the experiment for the Vermillion County sample revealed a significant decrease in permeability and porosity. However the Knox County sample had a minor increase in permeability and porosity. Geochemical analyses (IC, ICP-MS, and ICP-OES) of brine geochemistry before and after the experiment show a decrease in pH and an increase

  5. High-Resolution Isotopic Monitoring of Cave Air CO2

    NASA Astrophysics Data System (ADS)

    Töchterle, Paul; Dublyansky, Yuri; Mandic, Magda; Stöbener, Nils; Jost, Hj; Spötl, Christoph

    2016-04-01

    This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1 s). The air temperature was independently monitored inside and outside the cave. This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1s). The air temperature was independently monitored inside and outside the cave. The data show two distinct patterns in terms of CO2 concentration and its isotopic composition, which are closely coupled with the temperature difference between the cave interior and the outside atmosphere. This gradient controls the direction of air flow in the cave on a seasonal to synoptic timescale (chimney-type ventilation). The summer circulation is characterised by CO2 closely resembling atmospheric values (pCO2 = 399 ± 12 ppm, δ13C = -8.5 ± 0.7 permil, δ18O = 8.1 ± 2.5 permil). The winter circulation mode features generally higher CO2 concentrations and lower isotopic compositions (pCO2 = 409 ± 14 ppm, δ13C = -10.1 ± 0.7 permil, δ18O = 2.3 ± 1.5 permil). The high temporal resolution of stable isotope data allows tracking cave air ventilation changes, including transient and short-lived ones. Moreover, the data make it possible to address concomitant geochemical processes, such as the input of atmospheric CO2 and the degassing of CO2 from seepage water. These processes would not be possible to quantify without the new generation of laser-based isotope ratio instruments represented by the Delta Ray.

  6. CO2 interaction with geomaterials.

    SciTech Connect

    Guthrie, George D.; Al-Saidi, Wissam A.; Jordan, Kenneth D.; Voora, Vamsee, K.; Romanov, Vyacheslav N.; Lopano, Christina L; Myshakin, Eugene M.; Hur, Tae Bong; Warzinski, Robert P.; Lynn, Ronald J.; Howard, Bret H.; Cygan, Randall Timothy

    2010-09-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas No.3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or 'geopolymer') theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  7. Geological Characterization, Capacity Estimates and Long-Term Fate of CO2 Storage in Deep Saline Aquifers in the Two Elk Energy Park Pilot Test site, Powder River Basin, Wyoming

    NASA Astrophysics Data System (ADS)

    Calvo, R.; Benson, S. M.

    2011-12-01

    The Energy Park (North America Power Group) is a commercial-scale demonstration project planned as a series of renewable and other electric power generation, carbon capture, sequestration and related facilities, located in the eastern side of the Powder River Basin, northeastern Wyoming. The site is located on top of several deep saline aquifers, depleted oil reservoirs, and coal seams. The Powder River basin was identified by NETL and Big Sky partnership as having high potential for CO2 sequestration. The aims of our current study were to identify and describe all porous sections below the proposed site, to estimate the capacity of each unit, and to conduct simulations to better understand the faith of injected CO2 between those different layers. The storage goal of the project is 3 Mt/year for 50 years of operation. The project is supported by the DOE. Detailed geological characterization of the section between the Madison Formation and the Mowry Shale was based on two wells, located ~10 km from the proposed site. Porous sandstone layers were identified in the Minnelusa, Spearfish, Sundance, Morrison, Lakota, and Dakota formations. Average porosity in all of those units is between 8 to 15%. These formations consist of interbedded sandstone and shale, with some anhydrite and dolomite layers in the Minnelusa Formation. Our interest was to examine the ability of these impermeable layers (shale, anhydrite, and dolomite) to act as local seal to the different porous units. Other shale dominant formations also occur in the section (Opeche, Fuson, Skull, and Mowry formations) and will act as major seals to the whole porous section. The complex stratigraphy and relatively low permeability of the rocks at this site appear to preclude identification of a single unit that can be used for CO2 storage. Instead, the most promising option is to inject CO2 into large thickness of sediments, resulting in the injection of a relatively small amount of CO2 into a number of formations

  8. Sequestration of CO2 by concrete carbonation.

    PubMed

    Galan, Isabel; Andrade, Carmen; Mora, Pedro; Sanjuan, Miguel A

    2010-04-15

    Carbonation of reinforced concrete is one of the causes of corrosion, but it is also a way to sequester CO2. The characteristics of the concrete cover should ensure alkaline protection for the steel bars but should also be able to combine CO2 to a certain depth. This work attempts to advance the knowledge of the carbon footprint of cement. As it is one of the most commonly used materials worldwide, it is very important to assess its impact on the environment. In order to quantify the capacity of cement based materials to combine CO2 by means of the reaction with hydrated phases to produce calcium carbonate, Thermogravimetry and the phenolphthalein indicator have been used to characterize several cement pastes and concretes exposed to different environments. The combined effect of the main variables involved in this process is discussed. The moisture content of the concrete seems to be the most influential parameter.

  9. Comparison between mechanisms of CO2 degassing from El Chichon volcanic lake, México, and Specchio di Venere lake, Pantelleria, Italia.

    NASA Astrophysics Data System (ADS)

    Jácome Paz, M. P.; Taran, Y.; Inguaggiato, S.; Collard, N.; Vita, F.; Pecoraino, G.

    2014-12-01

    We present results of the CO2 diffuse emission from the surface of two volcanic lakes: El Chichón (EC) in Mexico and Specchio di Venere (SV) on Pantelleria Island, Italy. Both lakes are drainless, have similar sizes (~2x105 m2) and similar input-output dynamics. However, they are drastically different in water chemistry. The SV lake is alkaline (pH >9) and of a high near constant salinity, whereas EC lake is acidic (pH 2.3) and of a low variable salinity. In the vicinity of both lakes there are thermal grounds with steam vents and hot springs and a high CO2 soil flux. The SV lake has high alkalinity (~70 meq/L), whereas the EC lake is characterized by high concentration of dissolved CO2. CO2 flux measurements from the surface of both lakes were made with the "floating" accumulation chamber. During the flux measuring, gas samples were taken for carbon isotopic analysis. Soil flux measurements were also made in the crater of El Chichon volcano and on the area adjacent to the SV lake. The preliminary results of CO2 fluxes indicate EC lake has a high CO2 flux with a mean value of 3500 g m-2 d-1, with the highest values alignment across NW-SE and NE-SW faults and a high degassing by bubbling gases, especially near the strongest NE fumarolic field. While SV has a mean value of the CO2 flux ~ 10 g m-2 d-1 and limited bubbling on the lake surface. High CO2 flux was measured from the soil near the lake at the Mofeta place. A net mean diffusion flux (without bubbles) from EC lake is about 350 times higher than that from SV lake (3500 g m-2 d-1 vs 10 g m-2 d-1). SV has the total CO2 flux by diffusion of ~3 ton d-1 from an area of 0.3 km2 and the total flux of 0.44 ton d-1 by bubbling areas at SW and S zones. The EC lake has the total CO2 flux of 840 ton d-1 from an area of 0.24 km2. The total CO2 output from SV is nevertheless about two times higher taking into account the seepage from the lake (~ 8 kg s-1) of highly carbonated water.

  10. Leaves: Elevated CO2 levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Burning fossil fuels and land use changes such as deforestation and urbanization have led to a dramatic rise in the concentration of carbon dioxide (CO2) in the atmosphere since the onset of the Industrial Revolution. The highly dilute CO2 from the atmosphere enters plant leaves where it is concentr...

  11. Geomechanical characterization of an Upper Triassic reservoir rock (Stuttgart Formation) in the NE German Basin (pilot site for CO2 storage at Ketzin, Germany)

    NASA Astrophysics Data System (ADS)

    Klapperer, S.; Moeck, I.; Backers, T.

    2012-04-01

    In order to investigate the influence of CO2storage in a 730-710 m deep saline aquifer of Upper Triassic siliciclastic rock, a pilot project was set up at an anticlinal structure near the city of Ketzin/Havel, west of Berlin. Three new wells were drilled and since June 2008, about 57,000 tons of CO2 (December 2011) have been injected. In 2011 an additional observation well was drilled. Lithologically, the Upper Triassic, which is referred asKeuper in Germany, consists of a multi-layered siliciclastic sequence ofpartly anhydriticclaystone, siltstone, sandstone and evaporitic deposits (halite, anhydrite and gypsum). Injection leads to a change of stress conditions in the reservoir and its faults wherefore it is necessary to understand and quantify structural geology, stress regime and geomechanical behavior from reservoir to cap rock. Notably, the interaction of faults, lithologic units and stress field in a multi layered sedimentary system might have a strong impact on fluid flow. The failure and faulting of the rock within a stress field is strongly governed by rock mechanical properties. Therefore a suite of geomechanical testing was undertaken on core material of reservoir rock. In particular the parameters unconfined compressive strength (UCS), Young's modulus E, Poisson's ratio ν, angle of internal friction ψ and cohesion c were determined. The results of the geomechanical tests show a surprisingly wide range of values within one lithological unit. For the UCS the values vary between 8.1 and 177.5 MPa at which high values were measured for highly cemented, medium grained sandstone whereas very low test results were noted for weakly cemented, medium grained sandstone. Quite low compressive strengths ranging between 15.8 and 19.8 MPa was measured for clayey, fine sandy siltstone. Measurements on the partly well cemented, medium grained sandstone indicate medium range values from 59 to 76.2 MPa. Other important properties for estimation of the mechanical

  12. CO2 Sequestration short course

    SciTech Connect

    DePaolo, Donald J.; Cole, David R; Navrotsky, Alexandra; Bourg, Ian C

    2014-12-08

    Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

  13. Removable Tensor Strainmeter and Vector Tiltmeter System for Use With Forward and Inverse Methods for Characterizing Deformation During CO2 Injection

    NASA Astrophysics Data System (ADS)

    DeWolf, S.; Murdoch, L. C.; Moysey, S. M.; Germanovich, L. N.; Hanna, A.; Smith, J. E.

    2015-12-01

    Injecting fluids into a well deforms the enveloping rocks in a complex pattern that increases in magnitude and expands outward with time. While this evolving strain field creates space needed to store these fluids, it can also signal problems. Fault slip occurs when stresses caused by injection reach a critical value, and maintaining stresses below a critical stress state is important for limiting the risk of faulting and subsequent leakage. Since it is impossible to measure stresses directly, the approach is to measure displacement or strain, and then calculate stress change. The geodetic research community has developed borehole strainmeters capable of measuring the horizontal strain tensor with high resolution (>1 nanostrain), but these require permanent installation and are too expensive to be abandoned after short term studies. A far less expensive, removable instrument capable of measuring four components of strain and two components of tilt has been developed. Each sensing component employs non-contact eddy current transducers capable of measuring nanometer displacements. While not as precise as permanent borehole instruments, this new removable system should be able to resolve ground deformations associated with 0.5 to 1 microstrain per day rates expected at a proposed CO2 injection site. This system should also be well-suited for aquifer monitoring as well as for some geophysical signals. Finite element techniques are used to simulate a field injection test within the Bartlesville sandstone reservoir at the Avant field CO2 storage analog site, Oklahoma. These models suggest that measuring strain change at shallow depths, on the scale of 100s of ft, can be used to monitor the proposed water injection during a water flooding operation at a depth of approximately 1700 ft. A set of stochastic optimization algorithms are then used to iteratively generate a sequence of parameter estimates, and a high performance cluster computer efficiently evaluates this

  14. Polymeric nanoporous materials fabricated with supercritical CO2 and CO2-expanded liquids.

    PubMed

    Zhang, Aijuan; Zhang, Qingkun; Bai, Hua; Li, Lei; Li, Jun

    2014-01-01

    Both academia and industries have put great efforts into developing non-destructive technologies for the fabrication of polymeric nanoporous materials. Such non-destructive technologies developed with supercritical CO2 (scCO2) and CO2-expanded liquids (CXLs) have been attracting more and more attention because they have been demonstrated to be green and effective media for porous polymer preparation and processing. In this tutorial review, we present several such new technologies with scCO2 and CXLs, which have the capacity to prepare polymeric nanoporous materials with unique morphologies. The fabricated nanoporous polymers have significantly improved the performance of polymeric monoliths and films, and have found wide applications as templates, antireflection coatings, low-k materials, tissue engineering scaffolds and filtration membranes. This tutorial review also introduces the associated characterization methods, including the imaging, scattering and physisorption techniques.

  15. Frozen Frozen CO2

    NASA Technical Reports Server (NTRS)

    2005-01-01

    2 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of frozen carbon dioxide in the south polar residual cap of Mars. Much of the south polar residual cap exhibits terrain that resembles stacks of sliced Swiss cheese, but this portion of the cap lacks the typical, circular depressions that characterize much of the region. Carbon dioxide on Mars freezes at a temperature of around 148 Kelvins, which is -125oC or about -193oF.

    Location near: 87.2oS, 28.4oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  16. Reinforced photocatalytic reduction of CO2 to CO by a ternary metal oxide NiCo2O4.

    PubMed

    Wang, Zhaoyu; Jiang, Min; Qin, Jiani; Zhou, Han; Ding, Zhengxin

    2015-06-28

    The work reported herein was the facile preparation of uniform urchin-like NiCo2O4 microspheres, and their use as an efficient and stable cocatalyst for photocatalytic CO2 reduction catalysis. A combined solvothermal-calcination strategy was applied to synthesize the NiCo2O4 material that was systematically characterized by physical and chemical measurements (e.g. SEM, TEM, XRD, XPS, EDX, elemental mapping and N2 physisorption analysis). By cooperation with a visible light photosensitizer, the NiCo2O4 material effectively promoted the deoxygenative reduction of CO2 to CO by more than twenty times under mild reaction conditions. The carbon origin of CO evolution was validated by (13)CO2 isotope tracer experiments. Various reaction parameters were examined and optimized, and a possible reaction mechanism was proposed. Furthermore, the stability and reusability of NiCo2O4 cocatalysts were firmly confirmed.

  17. Use of geophysical methods to map subsurface features at levee seepage locations

    NASA Astrophysics Data System (ADS)

    Brackett, Thomas C.

    The Great Flood of 2011 caused moderate to severe seepage and piping along the Mississippi River levees in Northwest Mississippi. The aim of this thesis was to implement geophysical techniques at two seepage locations in order to give a better understanding of the causes of underseepage and information on how to mitigate the problem. Sites near Rena Lara in Coahoma County and near Francis in Bolivar County were chosen to conduct this survey. Electrical Resistivity Tomography (ERT) and Electromagnetic Induction (EM) surveys were conducted on and adjacent to levees to identify seepage pathways and any dominant geological features at the sites. Results from geophysical surveys revealed that Francis and Rena Laura each had a prominent geomorphologic feature that was attributing to underseepage. Seepage at Francis was the result of a sand filled channel capped by a clay overburden. Permeable materials at the base of the channel served as a conduit for transporting river water beneath the levee. The seepage surfaced as sand boils where the overlying clay overburden was thin or non-existent. Investigations at the Rena Lara site revealed a large, clay-filled swale extending beneath the levee. The clay within the swale has relatively low horizontal permeability, and concentrated the seepage flow towards more permeable zones on the flanks of the swale. This resulted in the formation of sand boils at the base of the levee. Both geomorphic features at Francis and Rena Lara were identified as surface drainages using remote sensing data. With the assistance of borehole and elevation data, geophysics was successfully used to characterize the features at each site. Properties such as permeability and clay content were derived from responses in electrical conductivity and used to build seepage models at each site. These models will hopefully be considered when determining seepage conditions and mitigation techniques at other sites along the levee.

  18. R Reactor seepage basins soil moisture and resistivity field investigation using cone penetrometer technology, Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Harris, M.K.

    2000-02-17

    The focus of this report is the summer 1999 investigation of the shallow groundwater system using cone penetrometer technology characterization methods to determine if the water table is perched beneath the R Reactor Seepage Basins (RRSBs).

  19. Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.

    PubMed

    Triantis, Charalampos; Tsotakos, Theodoros; Tsoukalas, Charalampos; Sagnou, Marina; Raptopoulou, Catherine; Terzis, Aris; Psycharis, Vassilis; Pelecanou, Maria; Pirmettis, Ioannis; Papadopoulos, Minas

    2013-11-18

    The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to β-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, β-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as β-diketone provides a solid example of the pharmacological potential of this system.

  20. Characterizing the potential for fault reactivation related to CO2 injection through subsurface structural mapping and stress field analysis, Wellington Field, Sumner County, KS

    NASA Astrophysics Data System (ADS)

    Schwab, D.; Bidgoli, T.; Taylor, M. H.

    2015-12-01

    South-central Kansas has experienced an unprecedented increase in seismic activity since 2013. The spatial and temporal relationship of the seismicity with brine disposal operations has renewed interest in the role of fluids in fault reactivation. This study focuses on determining the suitability of CO2 injection into a Cambro-Ordovician reservoir for long-term storage and a Mississippian reservoir for enhanced oil recovery in Wellington Field, Sumner County, Kansas. Our approach for determining the potential for induced seismicity has been to (1) map subsurface faults and estimate in-situ stresses, (2) perform slip and dilation tendency analysis to identify optimally-oriented faults relative to the estimated stress field, and (3) monitor surface deformation through cGPS data and InSAR imaging. Through the use of 3D seismic reflection data, 60 near vertical, NNE-striking faults have been identified. The faults range in length from 140-410 m and have vertical separations of 3-32m. A number of faults appear to be restricted to shallow intervals, while others clearly cut the top basement reflector. Drilling-induced tensile fractures (N=78) identified from image logs and inversion of earthquake focal mechanism solutions (N=54) are consistent with the maximum horizontal stress (SHmax) oriented ~E-W. Both strike-slip and normal-slip fault plane solutions for earthquakes near the study area suggest that SHmax and Sv may be similar in magnitude. Estimates of stress magnitudes using step rate tests (Shmin = 2666 psi), density logs (Sv = 5308 psi), and calculations from wells with drilling induced tensile fractures (SHmax = 4547-6655 psi) are determined at the gauge depth of 4869ft. Preliminary slip and dilation tendency analysis indicates that faults striking 0°-20° are stable, whereas faults striking 26°-44° may have a moderate risk for reactivation with increasing pore-fluid pressure.

  1. Development of a stable MnCo2O4 cocatalyst for photocatalytic CO2 reduction with visible light.

    PubMed

    Wang, Sibo; Hou, Yidong; Wang, Xinchen

    2015-02-25

    The synthesis of uniform MnCo2O4 microspheres and their cooperation with a visible light harvester to achieve efficient photocatalytic CO2 reduction under ambient conditions are reported here. The MnCo2O4 materials were prepared by a facile two-step solvothermal-calcination method and were characterized by XRD, SEM, TEM, EDX, XPS, elemental mapping, and N2 adsorption measurements. By using the MnCo2O4 microspheres as a heterogeneous cocatalyst, the photocatalytic performance of the CO2-to-CO conversion catalysis was remarkably enhanced, and no decrease in the promotional effect of the cocatalyst was observed after repeatedly operating the reaction for six cycles. (13)CO2 isotope tracer experiments verified that the CO product originated from the CO2 reactant. The effect of synthetic conditions and various reaction parameters on the photocatalytic activity of the system were investigated and optimized. The stability of the MnCo2O4 cocatalyst in the CO2 reduction system was confirmed by several techniques. Moreover, a possible mechanism for MnCo2O4-cocatalyzed CO2 photoreduction catalysis is proposed.

  2. CO2 sequestration in basalts: laboratory measurements

    NASA Astrophysics Data System (ADS)

    Otheim, L. T.; Adam, L.; van Wijk, K.; McLing, T. L.; Podgorney, R. K.

    2010-12-01

    Geologic sequestration of CO2 is proposed as the only promising large-scale method to help reduce CO2 gas emission by its capture at large point sources and subsequent long-term storage in deep geologic formations. Reliable and cost-effective monitoring will be important aspect of ensuring geological sequestration is a safe, effective, and acceptable method for CO2 emissions mitigation. Once CO2 injection starts, seismic methods can be used to monitor the migration of the carbon dioxide plume. To calibrate changes in rock properties from field observations, we propose to first analyze changes in elastic properties on basalt cores. Carbon dioxide sequestration in basalt rocks results in fluid substitution and mixing of CO2 with water and rock mineralizations. Carbon dioxide sequestration in mafic rocks creates reactions such as Mg2SiO 4 + CaMgSi2O 6 + 4CO2 = Mg 3Ca(CO 3) 4 + 3SiO2 whereby primary silicate minerals within the basalt react with carbonic acid laden water to creating secondary carbonate minerals and silicates. Using time-lapse laboratory scale experiments, such as laser generated ultrasonic wave propagation; it is possible to observe small changes in the physical properties of a rock. We will show velocity and modulus measurements on three basalt core samples for different saturation. The ultimate goal of the project is to track seismic changes due to fluid substitution and mineralization. The porosity of our basalts ranges from 8% to 12%, and the P-wave velocity increases by 20% to 40% from dry to water saturated conditions. Petrographic analysis (CT-scans, thin sections, XRF, XRf) will aid in the characterization of the mineral structure in these basalts and its correlation to seismic properties changes resulting from fluid substitution and mineralization.

  3. Flow rate logging seepage meter

    NASA Technical Reports Server (NTRS)

    Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

    1996-01-01

    An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

  4. Advanced reservoir characterization and evaluation of CO2 gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1996--August 31, 1997

    SciTech Connect

    McDonald, P.

    1998-06-01

    The objective of the Spraberry CO{sub 2} pilot project is to determine the technical and economic feasibility of continuous CO{sub 2} injection in the naturally fractured reservoirs of the Spraberry Trend. In order to describe, understand, and model CO{sub 2} flooding in the naturally fractured Spraberry reservoirs, characterization of the fracture system is a must. Additional reservoir characterization was based on horizontal coring in the second year of the project. In addition to characterization of natural fractures, horizontal coring has confirmed a previously developed rock model for describing the Spraberry Trend shaly sands. A better method for identifying Spraberry pay zones has been verified. The authors have completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. The authors have completed extensive imbibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. The authors have also made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. They have completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix.

  5. CO2 permeability of fractured cap rocks - experiments and numerical simulations (CO2Seals)

    NASA Astrophysics Data System (ADS)

    (Draeger), Ines Rick; Clauser, Christoph

    2010-05-01

    for this purpose including generic structural geological faults and comprising Mesozoic and Cenozoic formations of the Northern German Basin. The mass of CO2 retained by a multi-barrier system including reservoirs and cap rocks is estimated by taking into account hydraulic property values of known fault systems and predicted or measured leakage rates, also from natural analogues. As a result, we provide conclusions with respect to the stability and tightness of cap rocks exposed to CO2 for long periods. Furthermore, potential CO2 leakage scenarios on different size- and time-scales are generated in addition to the characterization of the CO2 sealing efficiency of low-permeable cap rocks. The CO2Seals project is funded by the R&D program GEOTECHNOLOGIEN of the German Federal Ministry of Education and Research (BMBF). It is a joint research project of RWTH Aachen University and the Karlsruhe Institute of Technology (KIT). The project is co-funded and accompanied scientifically by the industry partner Shell International Exploration and Production, Netherlands.

  6. Co2 On Titan's Surface

    NASA Astrophysics Data System (ADS)

    McCord, Thomas B.; Combe, J.; Hayne, P.; Hansen, G. B.

    2007-10-01

    Evidence is reported for the presence of CO2 on the surface of Titan from the Cassini VIMS (an imaging visual and IR spectrometer) data (McCord et al., 2006, 2007). CO2 can be expected on Titan from basic planetary evolution models. It was also suggested as a plausible spectral component for bright material near the Huygens landing site (Rodriguez et al., 2006), based on structure in the 1.59-µm region. Hartung et al. (2006) searched for CO2 in one hemisphere, but they were able only to set an upper limit on the possible spatial coverage by pure CO2. Barnes et al., (2006) suggested CO2 as a possible candidate material for a 5-µm-bright region, named Tsegihi, based on the high 5-µm reflectance. However, these results are not inconsistent with our report. The evidence we report is three-fold: 1) A weak absorption near 4.9 µm in the 5-µm methane window for the Tui Regio region; 2) The spectral contrast between the 2.7- and 2.8-µm methane subwindows for the regions exhibiting the 4.9-µm absorption, with stronger absorption correlating with stronger contrast; and 3) the overall shape of the CO2 spectrum (for several grain-sizes) is consistent with the spectrum of one of the fundamental surface spectral components, as deduced by spectral mixture analysis modeling. The Tui Regio feature exhibits the strongest evidence in all three categories. Studies of this feature's morphology and albedo markings have suggested to some that it may be an active cryovolcanic feature (Barnes et al., 2006). If so, CO2 could be erupting and depositing as a frost. This likely happened elsewhere and at other times. Thus, CO2 could be a major constituent of the surface, but over time it may be mixed with other constituents, such as spectrally neutral organics raining from the atmosphere, thereby reducing the strength of its spectral signature.

  7. The study of a potential CO2 repository: Integrating laboratory and field geophysical experiments to characterize the upper Muschelkalk aquifer (northern Switzerland)

    NASA Astrophysics Data System (ADS)

    Almqvist, B.; Zappone, A. S.; Misra, S.; Diamond, L.

    2011-12-01

    The upper Muschelkalk saline aquifer consists of partly dolomitized to completely dolomitized carbonate rocks of mid Triassic age (~230 Ma). This aquifer is present throughout the Swiss Molasse Basin (SMB), north of the Alps. A regional appraisal of the SMB indicates that this Formation is a potential host aquifer for sequestered CO2. However, the spatial distribution and heterogeneity of the porosity, permeability and other relevant physical and mechanical properties of the upper Muschelkalk are still poorly known. The uncertainty in this knowledge stems mainly from the weakly developed oil and gas exploration industry in Switzerland. We use an integrated approach to better constrain the aquifer physical properties, which couples field scale geophysical surveys (borehole logging and seismic reflection profiles) with laboratory analytical data. Here we focus on a set of boreholes from northern Switzerland, where geophysical data and drill core useable for laboratory measurements are available. Two sub-units comprise the upper Muschelkalk Formation. The stratigraphically higher part is a fossiliferous dolomite (>90 vol% CaMg(CO3)2; Trigodonusdolomit). The underlying unit, is composed of micritic calcite and dolomite layers interbedded with fossil-rich layers (Hauptmuschelkalk). Although both units are part of the aquifer formation, they appear to have distinctly different physical properties. The transition from Trigodonusdolomit to the Hauptmuschelkalk is marked by an increase in the sonic velocity, density and acoustic impedance. The magnitude of increase in sonic velocity can be up to 500 m/s, accompanied by an increase in acoustic impedance from 8500 to 15500 (m/s*g/cm3), but varies between the different boreholes. Poisson's ratio, determined from a single borehole, show sharp decrease at the transition. The origin of the changes in the geophysical data is likely reflecting differences in porosity and mineral composition in the Trigodonusdolomit and

  8. Seepage erosion mechanisms of bank collapse: three-dimensional seepage particle mobilization and undercutting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seepage flow initiates undercutting, similar to development and headward migration of internal gullies, by liquefaction of soil particles, followed by mass wasting of the bank. Although seepage erosion has three-dimensional characteristics, two-dimensional lysimeters have been used in previous resea...

  9. CO2 studies remain key to understanding a future world.

    PubMed

    Becklin, Katie M; Walker, S Michael; Way, Danielle A; Ward, Joy K

    2017-04-01

    Contents 34 I. 34 II. 36 III. 37 IV. 37 V. 38 38 References 38 SUMMARY: Characterizing plant responses to past, present and future changes in atmospheric carbon dioxide concentration ([CO2 ]) is critical for understanding and predicting the consequences of global change over evolutionary and ecological timescales. Previous CO2 studies have provided great insights into the effects of rising [CO2 ] on leaf-level gas exchange, carbohydrate dynamics and plant growth. However, scaling CO2 effects across biological levels, especially in field settings, has proved challenging. Moreover, many questions remain about the fundamental molecular mechanisms driving plant responses to [CO2 ] and other global change factors. Here we discuss three examples of topics in which significant questions in CO2 research remain unresolved: (1) mechanisms of CO2 effects on plant developmental transitions; (2) implications of rising [CO2 ] for integrated plant-water dynamics and drought tolerance; and (3) CO2 effects on symbiotic interactions and eco-evolutionary feedbacks. Addressing these and other key questions in CO2 research will require collaborations across scientific disciplines and new approaches that link molecular mechanisms to complex physiological and ecological interactions across spatiotemporal scales.

  10. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    NASA Astrophysics Data System (ADS)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2

  11. Impact of atmospheric CO2 levels on continental silicate weathering

    NASA Astrophysics Data System (ADS)

    Beaulieu, E.; GoddéRis, Y.; Labat, D.; Roelandt, C.; Oliva, P.; Guerrero, B.

    2010-07-01

    Anthropogenic sources are widely accepted as the dominant cause for the increase in atmospheric CO2 concentrations since the beginning of the industrial revolution. Here we use the B-WITCH model to quantify the impact of increased CO2 concentrations on CO2 consumption by weathering of continental surfaces. B-WITCH couples a dynamic biogeochemistry model (LPJ) and a process-based numerical model of continental weathering (WITCH). It allows simultaneous calculations of the different components of continental weathering fluxes, terrestrial vegetation dynamics, and carbon and water fluxes. The CO2 consumption rates are estimated at four different atmospheric CO2 concentrations, from 280 up to 1120 ppmv, for 22 sites characterized by silicate lithologies (basalt, granite, or sandstones). The sensitivity to atmospheric CO2 variations is explored, while temperature and rainfall are held constant. First, we show that under 355 ppmv of atmospheric CO2, B-WITCH is able to reproduce the global pattern of weathering rates as a function of annual runoff, mean annual temperature, or latitude for silicate lithologies. When atmospheric CO2 increases, evapotranspiration generally decreases due to progressive stomatal closure, and the soil CO2 pressure increases due to enhanced biospheric productivity. As a result, vertical drainage and soil acidity increase, promoting CO2 consumption by mineral weathering. We calculate an increase of about 3% of the CO2 consumption through silicate weathering (mol ha-1 yr-1) for 100 ppmv rise in CO2. Importantly, the sensitivity of the weathering system to the CO2 rise is not uniform and heavily depends on the climatic, lithologic, pedologic, and biospheric settings.

  12. Demonstration of a Novel, Integrated, Multi-Scale Procedure for High-Resolution 3D Reservoir Characterization and Improved CO2-EOR/Sequestration Management, SACROC Unit

    SciTech Connect

    Scott R. Reeves

    2007-09-30

    The primary goal of this project was to demonstrate a new and novel approach for high resolution, 3D reservoir characterization that can enable better management of CO{sub 2} enhanced oil recovery (EOR) projects and, looking to the future, carbon sequestration projects. The approach adopted has been the subject of previous research by the DOE and others, and relies primarily upon data-mining and advanced pattern recognition approaches. This approach honors all reservoir characterization data collected, but accepts that our understanding of how these measurements relate to the information of most interest, such as how porosity and permeability vary over a reservoir volume, is imperfect. Ideally the data needed for such an approach includes surface seismic to provide the greatest amount of data over the entire reservoir volume of interest, crosswell seismic to fill the resolution gap between surface seismic and wellbore-scale measurements, geophysical well logs to provide the vertical resolution sought, and core data to provide the tie to the information of most interest. These data are combined via a series of one or more relational models to enable, in its most successful application, the prediction of porosity and permeability on a vertical resolution similar to logs at each surface seismic trace location. In this project, the procedure was applied to the giant (and highly complex) SACROC unit of the Permian basin in West Texas, one of the world's largest CO{sub 2}-EOR projects and a potentially world-class geologic sequestration site. Due to operational scheduling considerations on the part of the operator of the field, the crosswell data was not obtained during the period of project performance (it is currently being collected however as part of another DOE project). This compromised the utility of the surface seismic data for the project due to the resolution gap between it and the geophysical well logs. An alternative approach was adopted that utilized a

  13. POST-PROCESSING ANALYSIS FOR THC SEEPAGE

    SciTech Connect

    Y. SUN

    2004-09-29

    This report describes the selection of water compositions for the total system performance assessment (TSPA) model of results from the thermal-hydrological-chemical (THC) seepage model documented in ''Drift-Scale THC Seepage Model'' (BSC 2004 [DIRS 169856]). The selection has been conducted in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2004 [DIRS 171334]). This technical work plan (TWP) was prepared in accordance with AP-2.27Q, ''Planning for Science Activities''. Section 1.2.3 of the TWP describes planning information pertaining to the technical scope, content, and management of this report. The post-processing analysis for THC seepage (THC-PPA) documented in this report provides a methodology for evaluating the near-field compositions of water and gas around a typical waste emplacement drift as these relate to the chemistry of seepage, if any, into the drift. The THC-PPA inherits the conceptual basis of the THC seepage model, but is an independently developed process. The relationship between the post-processing analysis and other closely related models, together with their main functions in providing seepage chemistry information for the Total System Performance Assessment for the License Application (TSPA-LA), are illustrated in Figure 1-1. The THC-PPA provides a data selection concept and direct input to the physical and chemical environment (P&CE) report that supports the TSPA model. The purpose of the THC-PPA is further discussed in Section 1.2. The data selection methodology of the post-processing analysis (Section 6.2.1) was initially applied to results of the THC seepage model as presented in ''Drift-Scale THC Seepage Model'' (BSC 2004 [DIRS 169856]). Other outputs from the THC seepage model (DTN: LB0302DSCPTHCS.002 [DIRS 161976]) used in the P&CE (BSC 2004 [DIRS 169860

  14. ACCURACY OF CO2 SENSORS

    SciTech Connect

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2008-10-01

    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  15. Microfluidic studies of CO2 sequestration by frustrated Lewis pairs.

    PubMed

    Voicu, Dan; Abolhasani, Milad; Choueiri, Rachelle; Lestari, Gabriella; Seiler, Caroline; Menard, Gabriel; Greener, Jesse; Guenther, Axel; Stephan, Douglas W; Kumacheva, Eugenia

    2014-03-12

    Frustrated Lewis pairs (FLPs) comprising sterically hindered Lewis acids and bases offer the capability to reversibly capture CO2 under mild reaction conditions. The determination of equilibrium constants and thermodynamic properties of these reactions should enable assessment of the efficiency of a particular FLP system for CO2 sequestration and provide insights for design of new, efficient formulations of FLP catalysts for CO2 capture. We have developed a microfluidic approach to studies of FLP-CO2 reactions, which provides their thermodynamic characterization that is not accessible otherwise. The approach enables the determination of the equilibrium reaction constants at different temperatures, the enthalpy, the entropy, and the Gibbs energy of these reactions, as well as the enhancement factor. The microfluidic methodology has been validated by applying it to the well-characterized reaction of CO2 with a secondary amine. The microfluidic approach can be applied for fundamental thermodynamic studies of other gas-liquid reactions.

  16. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    NASA Astrophysics Data System (ADS)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  17. Multi-scale modeling of CO2 dispersion leaked from seafloor off the Japanese coast.

    PubMed

    Kano, Yuki; Sato, Toru; Kita, Jun; Hirabayashi, Shinichiro; Tabeta, Shigeru

    2010-02-01

    A numerical simulation was conducted to predict the change of pCO(2) in the ocean caused by CO(2) leaked from an underground aquifer, in which CO(2) is purposefully stored. The target space of the present model was the ocean above the seafloor. The behavior of CO(2) bubbles, their dissolution, and the advection-diffusion of dissolved CO(2) were numerically simulated. Here, two cases for the leakage rate were studied: an extreme case, 94,600 t/y, which assumed that a large fault accidentally connects the CO(2) reservoir and the seafloor; and a reasonable case, 3800 t/y, based on the seepage rate of an existing EOR site. In the extreme case, the calculated increase in DeltapCO(2) experienced by floating organisms was less than 300 ppm, while that for immobile organisms directly over the fault surface periodically exceeded 1000 ppm, if momentarily. In the reasonable case, the calculated DeltapCO(2) and pH were within the range of natural fluctuation.

  18. Update on CO2 emissions

    SciTech Connect

    Friedingstein, P.; Houghton, R.A.; Marland, Gregg; Hackler, J.; Boden, Thomas A; Conway, T.J.; Canadell, J.G.; Raupach, Mike; Ciais, Philippe; Le Quere, Corrine

    2010-12-01

    Emissions of CO2 are the main contributor to anthropogenic climate change. Here we present updated information on their present and near-future estimates. We calculate that global CO2 emissions from fossil fuel burning decreased by 1.3% in 2009 owing to the global financial and economic crisis that started in 2008; this is half the decrease anticipated a year ago1. If economic growth proceeds as expected2, emissions are projected to increase by more than 3% in 2010, approaching the high emissions growth rates that were observed from 2000 to 20081, 3, 4. We estimate that recent CO2 emissions from deforestation and other land-use changes (LUCs) have declined compared with the 1990s, primarily because of reduced rates of deforestation in the tropics5 and a smaller contribution owing to forest regrowth elsewhere.

  19. Measurements of CO2 Carbon Stable Isotopes at Artificial and Natural Analog Sites

    NASA Astrophysics Data System (ADS)

    Humphries, S. D.; Clegg, S. M.; Rahn, T.; Fessenden, J. E.; Dobeck, L.; Spangler, L.; McLing, T. L.

    2010-12-01

    Carbon storage in geologic formations is one method to prevent carbon dioxide (CO2), produced by fossil fuel combustion, from entering the Earth's atmosphere. The monitoring, verification and accounting (MVA) of geologically sequestered CO2 is critical to the operation of a geologic storage site. Surface MVA techniques need to identify seepage from the sequestration reservoir at or below ambient CO2 concentrations. The CO2 carbon stable isotope ratio of is a sensitive diagnostic signature that can distinguish between anthropogenic and natural sources of CO2. Frequency Modulated spectroscopy (FMS) is an ultra-sensitive version of absorption spectroscopy that is capable of detecting the CO2 carbon stable isotope ratios. The technique involves phase modulation of the laser such that two side bands, spaced wider than the absorption feature of interest (in this case +/-2 GHz) are created. The signal is mixed with the local oscillator yielding a signal proportional to the species concentration. This FMS signature is recorded at multiple wavelengths to obtain the CO2 carbon isotope ratio.Two instruments using the FMS technique have been built and tested at LANL. One instrument draws ambient air into a multi-pass cell for a measurement, point source measurements. The other instrument uses an open-air path, tested up to 160 m (round trip), to measure the CO2 carbon isotopic ratio along the beam path, column average measurements. In this paper, results from multiple field deployments of one or both of the instruments will be presented. The Zero Emissions Research & Technology (ZERT) group at Montana State University established a field test site where controlled amounts of CO2 are released to test the performance of CO2 detection instruments and measurement techniques. The field site allows a controlled flow rate of CO2 to be released into the near surface through a 100 m long horizontal pipe. In July of 2009, a release was conducted, with a uniform flow rate of 0.2 tons per

  20. A Tube Seepage Meter for In Situ Measurement of Seepage Rate and Groundwater Sampling.

    PubMed

    Solder, John E; Gilmore, Troy E; Genereux, David P; Solomon, D Kip

    2016-07-01

    We designed and evaluated a "tube seepage meter" for point measurements of vertical seepage rates (q), collecting groundwater samples, and estimating vertical hydraulic conductivity (K) in streambeds. Laboratory testing in artificial streambeds show that seepage rates from the tube seepage meter agreed well with expected values. Results of field testing of the tube seepage meter in a sandy-bottom stream with a mean seepage rate of about 0.5 m/day agreed well with Darcian estimates (vertical hydraulic conductivity times head gradient) when averaged over multiple measurements. The uncertainties in q and K were evaluated with a Monte Carlo method and are typically 20% and 60%, respectively, for field data, and depend on the magnitude of the hydraulic gradient and the uncertainty in head measurements. The primary advantages of the tube seepage meter are its small footprint, concurrent and colocated assessments of q and K, and that it can also be configured as a self-purging groundwater-sampling device.

  1. Use of an Electromagnetic Seepage Meter to Investigate Temporal Variability in Lake Seepage

    USGS Publications Warehouse

    Rosenberry, D.O.; Morin, R.H.

    2004-01-01

    A commercially available electromagnetic flowmeter is attached to a seepage cylinder to create an electromagnetic seepage meter (ESM) for automating measurement of fluxes across the sediment/water interface between ground water and surface water. The ESM is evaluated through its application at two lakes in New England, one where water seeps into the lake and one where water seeps out of the lake. The electromagnetic flowmeter replaces the seepage-meter bag and provides a continuous series of measurements from which temporal seepage processes can be investigated. It provides flow measurements over a range of three orders of magnitude, and contains no protruding components or moving parts. The ESM was used to evaluate duration of seepage disturbance following meter installation and indicated natural seepage rates resumed approximately one hour following meter insertion in a sandy lakebed. Lakebed seepage also varied considerably in response to lakebed disturbances, near-shore waves, and rain-falls, indicating hydrologic processes are occurring in shallow lakebed settings at time scales that have largely gone unobserved.

  2. The CO2nnect activities

    NASA Astrophysics Data System (ADS)

    Eugenia, Marcu

    2014-05-01

    Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

  3. Hazardous indoor CO2 concentrations in volcanic environments.

    PubMed

    Viveiros, Fátima; Gaspar, João L; Ferreira, Teresa; Silva, Catarina

    2016-07-01

    Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities.

  4. Characterizing a Mississippian Carbonate Reservoir for CO2-EOR and Carbon Geosequestration: Applicability of Existing Rock Physics Models and Implications to Feasibility of a Time Lapse Monitoring Program in the Wellington Oil Field, Sumner County, Kansas.

    NASA Astrophysics Data System (ADS)

    Lueck, A. J.; Raef, A. E.

    2015-12-01

    This study will focus on characterizing subsurface rock formations of the Wellington Field, in Sumner County, Kansas, for both geosequestration of carbon dioxide (CO2) in the saline Arbuckle formation and enhanced oil recovery of a depleting Mississippian oil reservoir. Multi-scale data including lithofacies core samples, X-ray diffraction, digital rock physics scans, scanning electron microscope (SEM) imaging, well log data including sonic and dipole sonic, and surface 3D seismic reflection data will be integrated to establish and/or validate a new or existing rock physics model that best represents our reservoir rock types and characteristics. We will acquire compressional wave velocity and shear wave velocity data from Mississippian and Arbuckle cores by running ultrasonic tests using an Ult 100 Ultrasonic System and a 12 ton hydraulic jack located in the geophysics lab in Thompson Hall at Kansas State University. The elastic constants Young's Modulus, Bulk Modulus, Shear (Rigidity) Modulus and Poisson's Ratio will be extracted from these velocity data. Ultrasonic velocities will also be compared to sonic and dipole sonic log data from the Wellington 1-32 well. These data will be integrated to validate a lithofacies classification statistical model, which will be and partially has been applied to the largely unknown saline Arbuckle formation, with hopes for a connection, perhaps via Poisson's ratio, allowing a time-lapse seismic feasibility assessment and potentially developing a transformation of compressional wave sonic velocities to shear wave sonic for all wells, where compressional wave sonic is available. We will also be testing our rock physics model by predicting effects of changing effective (brine + CO2 +hydrocarbon) fluid composition on seismic properties and the implications on feasibility of seismic monitoring. Lessons learned from characterizing the Mississippian are essential to understanding the potential of utilizing similar workflows for the

  5. DESIGN AND IMPLEMENTATION OF A CO2 FLOOD UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL INJECTION WELLS IN A SHALLOW SHELF CARBONATE APPROACHING WATERFLOOD DEPLETION

    SciTech Connect

    K.J. Harpole; Ed G. Durrett; Susan Snow; J.S. Bles; Carlon Robertson; C.D. Caldwell; D.J. Harms; R.L. King; B.A. Baldwin; D. Wegener; M. Navarrette

    2002-09-01

    The purpose of this project was to economically design an optimum carbon dioxide (CO{sub 2}) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO{sub 2} horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields. The Unit was a mature waterflood with water cut exceeding 95%. Oil must be mobilized through the use of a miscible or near-miscible fluid to recover significant additional reserves. Also, because the unit was relatively small, it did not have the benefit of economies of scale inherent in normal larger scale projects. Thus, new and innovative methods were required to reduce investment and operating costs. Two primary methods used to accomplish improved economics were use of reservoir characterization to restrict the flood to the higher quality rock in the unit and use of horizontal injection wells to cut investment and operating costs. The project consisted of two budget phases. Budget Phase I started in June 1994 and ended late June 1996. In this phase Reservoir Analysis, Characterization Tasks and Advanced Technology Definition Tasks were completed. Completion enabled the project to be designed, evaluated, and an Authority for Expenditure (AFE) for project implementation submitted to working interest owners for approval. Budget Phase II consisted of the implementation and execution of the project in the field. Phase II was completed in July 2001. Performance monitoring, during Phase II, by mid 1998 identified the majority of producing wells which under performed their anticipated withdrawal rates. Newly drilled and re-activated wells had lower offtake rates than originally forecasted. As a result of poor offtake, higher reservoir pressure was a concern

  6. Reducing cement's CO2 footprint

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  7. Turbulent flow statistics of vegetative channel with seepage

    NASA Astrophysics Data System (ADS)

    Devi, Thokchom Bebina; Kumar, Bimlesh

    2015-12-01

    The present study is carried out for studying the impact of submerged, flexible vegetation in a channel where downward seepage occurs. Laboratory experiments on artificial vegetation of two different heights, 8 cm and 6 cm, were conducted for no-seepage, 10% seepage and 15% seepage cases. Vegetation height is an important parameter in influencing the flow characteristics in a vegetated channel, where velocity is reduced near the top of the vegetation. Results show that velocity measured at upstream vegetation section is always higher than the downstream section even with the application of downward seepage. The maximum value of Reynolds stress occurs near the top of the vegetation. When the flow enters the vegetation section, the local effect of the presence of vegetation on sediment transport is more at the upstream vegetation section and then decreases which is shown by higher Reynolds stress at the upstream as compared to downstream vegetation section highlighting the importance of vegetation in providing as an erosion control. The maximum Reynolds stress at no seepage is increased by a percentage of 17% for 10% seepage and average of 30.5% for 15% seepage. The turbulence intensities at no seepage are increased by an average value of 15% for 10% seepage and 25% for 15% seepage. The reduction of Reynolds stress and turbulent intensities along the longitudinal direction implies the importance of using vegetation as a river restoration measure providing considerable stability to channels. Third order moments highlight that downward seepage increases the streamwise flux and decreases the upward flux.

  8. A seepage meter designed for use in flowing water

    USGS Publications Warehouse

    Rosenberry, D.O.

    2008-01-01

    Seepage meters provide one of the most direct means to measure exchange of water across the sediment-water interface, but they generally have been unsuitable for use in fluvial settings. Although the seepage bag can be placed inside a rigid container to minimize velocity head concerns, the seepage cylinder installed in the sediment bed projects into and disrupts the flow field, altering both the local-scale fluid exchange as well as measurement of that exchange. A low-profile seepage meter designed for use in moving water was tested in a seepage meter flux tank where both current velocity and seepage velocity could be controlled. The conical seepage cylinder protrudes only slightly above the sediment bed and is connected via tubing to a seepage bag or flowmeter positioned inside a rigid shelter that is located nearby where current velocity is much slower. Laboratory and field tests indicate that the net effect of the small protrusion of the seepage cylinder into the surface water flow field is inconsequentially small for surface water currents up to 65 cm s-1. Current velocity affects the variability of seepage measurements; seepage standard deviation increased from ???2 to ???6 cm d-1 as current velocity increased from 9 to 65 cm s-1. Substantial bias can result if the shelter is not placed to minimize hydraulic gradient between the bag and the seepage cylinder.

  9. Eddy Covariance Method for CO2 Emission Measurements: CCS Applications, Principles, Instrumentation and Software

    NASA Astrophysics Data System (ADS)

    Burba, George; Madsen, Rod; Feese, Kristin

    2013-04-01

    The Eddy Covariance method is a micrometeorological technique for direct high-speed measurements of the transport of gases, heat, and momentum between the earth's surface and the atmosphere. Gas fluxes, emission and exchange rates are carefully characterized from single-point in-situ measurements using permanent or mobile towers, or moving platforms such as automobiles, helicopters, airplanes, etc. Since the early 1990s, this technique has been widely used by micrometeorologists across the globe for quantifying CO2 emission rates from various natural, urban and agricultural ecosystems [1,2], including areas of agricultural carbon sequestration. Presently, over 600 eddy covariance stations are in operation in over 120 countries. In the last 3-5 years, advancements in instrumentation and software have reached the point when they can be effectively used outside the area of micrometeorology, and can prove valuable for geological carbon capture and sequestration, landfill emission measurements, high-precision agriculture and other non-micrometeorological industrial and regulatory applications. In the field of geological carbon capture and sequestration, the magnitude of CO2 seepage fluxes depends on a variety of factors. Emerging projects utilize eddy covariance measurement to monitor large areas where CO2 may escape from the subsurface, to detect and quantify CO2 leakage, and to assure the efficiency of CO2 geological storage [3,4,5,6,7,8]. Although Eddy Covariance is one of the most direct and defensible ways to measure and calculate turbulent fluxes, the method is mathematically complex, and requires careful setup, execution and data processing tailor-fit to a specific site and a project. With this in mind, step-by-step instructions were created to introduce a novice to the conventional Eddy Covariance technique [9], and to assist in further understanding the method through more advanced references such as graduate-level textbooks, flux networks guidelines, journals

  10. Potential for seepage erosion of landslide dam

    USGS Publications Warehouse

    Meyer, W.; Schuster, R.L.; Sabol, M.A.

    1994-01-01

    The failure potential of the debris-avalanche dam at Castle Lake near Mount St. Helens, Washington, by three processes of seepage erosion (1) Heave; (2) piping; and (3) internal erosion, is examined. Results indicated that the dam is stable against piping but potentially locally unstable against heave. -from Authors

  11. SEEPAGE, a new MODFLOW DRAIN package.

    PubMed

    Batelaan, O; De Smedt, F

    2004-01-01

    The prediction of the location of ground water discharge areas is a key aspect for the protection and (re)development of ground water-dependent wetlands. Ground water discharge areas can be simulated with MODFLOW using the DRAIN package by setting the drain level equal to the topography, while the conductance is mostly set to an arbitrary high value. However, conceptual and practical problems arise in the calculation of the ground water discharge by the DRAIN package as calculated water tables above the land surface, difficult parameterization of the conductance, and large water balance errors. To overcome these problems, a new SEEPAGE package for MODFLOW is proposed. The basic idea of this package is an adaptable constant head cell. It has a variable head, unless the ground water rises above the seepage level, in which case it has a constant head cell. The estimation of the ground water discharge location along a homogeneous, isotropic, linear sloping profile is used to verify the model and to compare it to the DRAIN solution. In an application to three basins in Belgium, it is shown that the SEEPAGE package can be used in combination with the DRAIN package in situations where an upper boundary for a free water table and additional resistance for drainage is required. It is clearly demonstrated that the identification and delineation of regional ground water discharge areas is more accurate using the SEEPAGE package.

  12. Drift-Scale THC Seepage Model

    SciTech Connect

    C.R. Bryan

    2005-02-17

    The purpose of this report (REV04) is to document the thermal-hydrologic-chemical (THC) seepage model, which simulates the composition of waters that could potentially seep into emplacement drifts, and the composition of the gas phase. The THC seepage model is processed and abstracted for use in the total system performance assessment (TSPA) for the license application (LA). This report has been developed in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2005 [DIRS 172761]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this report. The plan for validation of the models documented in this report is given in Section 2.2.2, ''Model Validation for the DS THC Seepage Model,'' of the TWP. The TWP (Section 3.2.2) identifies Acceptance Criteria 1 to 4 for ''Quantity and Chemistry of Water Contacting Engineered Barriers and Waste Forms'' (NRC 2003 [DIRS 163274]) as being applicable to this report; however, in variance to the TWP, Acceptance Criterion 5 has also been determined to be applicable, and is addressed, along with the other Acceptance Criteria, in Section 4.2 of this report. Also, three FEPS not listed in the TWP (2.2.10.01.0A, 2.2.10.06.0A, and 2.2.11.02.0A) are partially addressed in this report, and have been added to the list of excluded FEPS in Table 6.1-2. This report has been developed in accordance with LP-SIII.10Q-BSC, ''Models''. This report documents the THC seepage model and a derivative used for validation, the Drift Scale Test (DST) THC submodel. The THC seepage model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC submodel uses a drift

  13. CO2 Acquisition Membrane (CAM)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.; Way, J. Douglas; Vlasse, Marcus

    2003-01-01

    The objective of CAM is to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes are targeted toward In Situ Resource Utilization (ISRU) applications that will operate in extraterrestrial environments and support future unmanned and human space missions. A primary application is the Sabatier Electrolysis process that uses Mars atmosphere CO2 as raw material for producing water, oxygen, and methane for rocket fuel and habitat support. Other applications include use as an inlet filter to collect and concentrate Mars atmospheric argon and nitrogen gases for habitat pressurization, and to remove CO2 from breathing gases in Closed Environment Life Support Systems (CELSS). CAM membrane materials include crystalline faujasite (FAU) zeolite and rubbery polymers such as silicone rubber (PDMS) that have been shown in the literature and via molecular simulation to favor adsorption and permeation of CO2 over nitrogen and argon. Pure gas permeation tests using commercial PDMS membranes have shown that both CO2 permeance and the separation factor relative to other gases increase as the temperature decreases, and low (Delta)P(Sub CO2) favors higher separation factors. The ideal CO2/N2 separation factor increases from 7.5 to 17.5 as temperature decreases from 22 C to -30 C. For gas mixtures containing CO2, N2, and Ar, plasticization decreased the separation factors from 4.5 to 6 over the same temperature range. We currently synthesize and test our own Na(+) FAU zeolite membranes using standard formulations and secondary growth methods on porous alumina. Preliminary tests with a Na(+) FAU membrane at 22 C show a He/SF6 ideal separation factor of 62, exceeding the Knudsen diffusion selectivity by an order of magnitude. This shows that the membrane is relatively free from large defects and associated non-selective (viscous flow) transport

  14. CO2 Washout Testing of NASA Space Suits

    NASA Technical Reports Server (NTRS)

    Norcross, Jason

    2012-01-01

    During the presentation "CO2 Washout Testing of NASA Spacesuits," Jason Norcross discussed the results of recent carbon dioxide CO2 washout testing of NASA spacesuits including the Rear Entry I-suit (REI), Enhanced Mobility Advanced Crew Escape Suit (EM-ACES), and possibly the ACES and Z-1 EVA prototype. When a spacesuit is used during ground testing, adequate CO2 washout must be provided for the suited subject. Symptoms of acute CO2 exposure depend on the partial pressure of CO2 (ppCO2) available to enter the lungs during respiration. The primary factors during ground-based testing that influence the ppCO2 level in the oronasal area include the metabolic rate of the subject and air flow through the suit. These tests were done to characterize inspired oronasal ppCO2 for a range of workloads and flow rates for which ground testing is nominally performed. During this presentation, Norcross provided descriptions of the spacesuits, test hardware, methodology, and results, as well as implications for future ground testing and verification of flight requirements.

  15. 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

  16. 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.

  17. Synthesis, physical-chemical characterization and electrochemical performance of GdBaCo2-xNixO5+δ (x = 0-0.8) as cathode materials for IT-SOFC application

    NASA Astrophysics Data System (ADS)

    Hu, Y.; Bogicevic, C.; Bouffanais, Y.; Giot, M.; Hernandez, O.; Dezanneau, G.

    2013-11-01

    GdBaCo2-xNixO5+δ (x = 0-0.8) cathode materials have been synthesized by a citrate-gel modified chemical route, by which we have achieved a high level of substitution up to x = 0.8. Oxygen stoichiometry at room temperature has been determined by iodometry and the structural evolution as a function of Ni content has been extracted from XRD patterns analysis. All compounds are orthorhombic at room temperature and a DSC analysis reveals that the high-temperature orthorhombic-to-tetragonal phase transition is observed at lower temperature as Ni substitution increases. Three compositions, with x = 0, 0.3 and 0.6, were then chosen for further characterization: high-temperature XRD has been performed confirming the abovementioned structural evolution with temperature and allowing to determine that Ni doping diminishes slightly the thermal expansion coefficient. According to 4-probe measurements, we show that these compounds present a high electronic conductivity, suitable for cathode materials. Finally, electrochemical characterization has been performed by AC impedance spectroscopy with symmetric cells using composite electrode showing an improvement of performance at intermediate substitution levels.

  18. Generation of expressed sequence tags from low-CO2 and high-CO2 adapted cells of Chlamydomonas reinhardtii.

    PubMed

    Asamizu, E; Miura, K; Kucho, K; Inoue, Y; Fukuzawa, H; Ohyama, K; Nakamura, Y; Tabata, S

    2000-10-31

    To characterize genes whose expression is induced in carbon-stress conditions, 12,969 and 13,450 5'-end expressed sequence tags (ESTs) were generated from cells grown in low-CO2 and high-CO2 conditions of the unicellular green alga, Chlamydomonas reinhardtii. These ESTs were clustered into 4436 and 3566 non-redundant EST groups, respectively. Comparison of their sequences with those of 3433 non-redundant ESTs previously generated from the cells under the standard growth condition indicated that 2665 and 1879 EST groups occurred only in the low-CO2 and high-CO2 populations, respectively. It was also noted that 96.2% and 96.0% of the cDNA species respectively obtained from the low-CO2 and high-CO2 conditions had no similar EST sequence deposited in the public databases. The EST species identified only in the low-CO2 treated cells included genes previously reported to be expressed specifically in low-CO2 acclimatized cells, suggesting that the ESTs generated in this study will be a useful source for analysis of genes related to carbon-stress acclimatization. The sequence information and search results of each clone will appear at the web site: http://www.kazusa.or.jp/en/plant/chlamy/EST/.

  19. Damage evaluation for crops exposed to a simulated leakage of geologically stored CO2 using hyperspectral imaging technology

    NASA Astrophysics Data System (ADS)

    Burud, Ingunn; Moni, Christophe; Flø, Andreas; Rolstad Denby, Cecilie; Rasse, Daniel

    2013-04-01

    simulated CO2 leak might have on the hyperspectral signature of a Norwegian oats crop. In order to test the effects of different intensity of leakage, a CO2 exposure field experiment was designed to create a longitudinal CO2 gradient. For this purpose a gas supply pipe was inserted at one end of a 6m by 3m experimental plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under a silt loam plough layer. CO2 was then injected at a rate of 2l.min-1 just after the oats had germinated at the end of June, and continued until it was harvested at the end of August. Then soil CO2 fluxes were recorded at the surface using a (60 x 60 cm) grid sampling pattern. Hyperspectral images of the experimental plot were taken at different dates during the gassing period using a SPECIM camera with 800 spectral bands, covering the wavelength range 400 - 1000 nm. The change in the reflectance spectra were characterized over time within the plot by the computation of various hyperspectral vegetation indices for small discretized spatial units (i.e. 10 cm by 10 cm square). The results showed that one month after injection, reduced plant growth, yellowing of the leaves and purple discoloration of the stems were observed just above the injection points were high CO2 fluxes had been identified. These high CO2 flux zones were further associated with an increase of the reflectance that occurred in the red region of the spectra indicating a decrease of the chlorophyll content in the plants. To conclude, plant health, as indicated by the hyperspectral signature, was closely related to the leakage pattern, indicating that hyperspectral imaging could be used to identify a CO2 seepage in an agricultural field. Acknowledgments This work is part of the RISCS project (Research into Impacts and Safety in CO2 Storage), funded by the EC 7th Framework Programme and by industry partners ENEL I&I, Statoil, Vattenfall AB, E.ON and RWE. R&D partners are BGS, CERTH, IMARES, OGS, PML, SINTEF

  20. Surface Condensation of CO2 onto Kaolinite

    SciTech Connect

    Schaef, Herbert T.; Glezakou, Vassiliki Alexandra; Owen, Antionette T.; Ramprasad, Sudhir; Martin, Paul F.; McGrail, B. Peter

    2014-02-11

    The fundamental adsorption behavior of gaseous and supercritical carbon dioxide (CO2) onto poorly crystalline kaolinite (KGa-2) at conditions relevant to geologic sequestration has been investigated using a quartz crystal microbalance (QCM) and density functional theory (DFT) methods. The QCM data indicated linear adsorption of CO2 (0-0.3 mmol CO2/g KGa-2) onto the kaolinite surface up through the gaseous state (0.186 g/cm3). However in the supercritical region, CO2 adsorption increases dramatically, reaching a peak (0.9-1.0 mmol CO2/g KGa-2) near 0.43 g/cm3, before declining rapidly to surface adsorption values equivalent or below gaseous CO2. This adsorption profile was not observed with He or N2. Comparative density functional studies of CO2 interactions with kaolinite surface models rule out CO2 intercalation and confirm that surface adsorption is favored up to approximately 0.35 g/cm3 of CO2, showing distorted T-shaped CO2-CO2 clustering, typical of supercritical CO2 aggregation over the surface as the density increases. Beyond this point, the adsorption energy gain for any additional CO2 becomes less than the CO2 interaction energy (~0.2 eV) in the supercritical medium resulting in overall desorption of CO2 from the kaolinite surface.

  1. Outsourcing CO2 within China

    PubMed Central

    Feng, Kuishuang; Davis, Steven J.; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-01-01

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country’s borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world’s largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China’s emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low–value-added but high–carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China. PMID:23754377

  2. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-08-01

    Oil sands comprise 30% of the world's oil reserves and the crude oil reserves in Canada's oil sands deposits are second only to Saudi Arabia. The extraction and processing of oil sands is much more challenging than for light sweet crude oils because of the high viscosity of the bitumen contained within the oil sands and because the bitumen is mixed with sand and contains chemical impurities such as sulphur. Despite these challenges, the importance of oil sands is increasing in the energy market. To our best knowledge this is the first peer-reviewed study to characterize volatile organic compounds (VOCs) emitted from Alberta's oil sands mining sites. We present high-precision gas chromatography measurements of 76 speciated C2-C10 VOCs (alkanes, alkenes, alkynes, cycloalkanes, aromatics, monoterpenes, oxygenates, halocarbons, and sulphur compounds) in 17 boundary layer air samples collected over surface mining operations in northeast Alberta on 10 July 2008, using the NASA DC-8 airborne laboratory as a research platform. In addition to the VOCs, we present simultaneous measurements of CO2, CH4, CO, NO, NO2, NOy, O3 and SO2, which were measured in situ aboard the DC-8. Methane, CO, CO2, NO, NO2, NOy, SO2 and 53 VOCs (e.g., halocarbons, sulphur species, NMHCs) showed clear statistical enhancements (up to 1.1-397×) over the oil sands compared to local background values and, with the exception of CO, were higher over the oil sands than at any other time during the flight. Twenty halocarbons (e.g., CFCs, HFCs, halons, brominated species) either were not enhanced or were minimally enhanced (< 10%) over the oil sands. Ozone levels remained low because of titration by NO, and three VOCs (propyne, furan, MTBE) remained below their 3 pptv detection limit throughout the flight. Based on their mutual correlations, the compounds emitted by the oil sands industry fell into two groups: (1) evaporative emissions from the oil sands and its products and/or from the diluent used to

  3. Infiltration and Seepage Through Fractured Welded Tuff

    SciTech Connect

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  4. Characterization of Leaf Blade- and Leaf Sheath-Associated Bacterial Communities and Assessment of Their Responses to Environmental Changes in CO2, Temperature, and Nitrogen Levels under Field Conditions

    PubMed Central

    Ikeda, Seishi; Tokida, Takeshi; Nakamura, Hirofumi; Sakai, Hidemitsu; Usui, Yasuhiro; Okubo, Takashi; Tago, Kanako; Hayashi, Kentaro; Sekiyama, Yasuyo; Ono, Hiroshi; Tomita, Satoru; Hayatsu, Masahito; Hasegawa, Toshihiro; Minamisawa, Kiwamu

    2015-01-01

    Rice shoot-associated bacterial communities at the panicle initiation stage were characterized and their responses to elevated surface water-soil temperature (ET), low nitrogen (LN), and free-air CO2 enrichment (FACE) were assessed by clone library analyses of the 16S rRNA gene. Principal coordinate analyses combining all sequence data for leaf blade- and leaf sheath-associated bacteria revealed that each bacterial community had a distinct structure, as supported by PC1 (61.5%), that was mainly attributed to the high abundance of Planctomycetes in leaf sheaths. Our results also indicated that the community structures of leaf blade-associated bacteria were more sensitive than those of leaf sheath-associated bacteria to the environmental factors examined. Among these environmental factors, LN strongly affected the community structures of leaf blade-associated bacteria by increasing the relative abundance of Bacilli. The most significant effect of FACE was also observed on leaf blade-associated bacteria under the LN condition, which was explained by decreases and increases in Agrobacterium and Pantoea, respectively. The community structures of leaf blade-associated bacteria under the combination of FACE and ET were more similar to those of the control than to those under ET or FACE. Thus, the combined effects of environmental factors need to be considered in order to realistically assess the effects of environmental changes on microbial community structures. PMID:25740174

  5. A comparative synthesis and physicochemical characterizations of Ni/Al2O3-MgO nanocatalyst via sequential impregnation and sol-gel methods used for CO2 reforming of methane.

    PubMed

    Aghamohammadi, Sogand; Haghighi, Mohammad; Karimipour, Samira

    2013-07-01

    Carbon dioxide reforming of methane is an interesting route for synthesis gas production especially over nano-sized catalysts. The present research deals with catalyst development for dry reforming of methane with the aim of reaching the most stable catalyst. Effect of preparation method, one of the most significant variables, on the properties of the catalysts was taken in to account. The Ni/Al2O3-MgO catalysts were prepared via sol-gel and sequential impregnation methods and characterized with XRD, FESEM, EDAX, BET and FTIR techniques. The reforming reactions were carried out using different feed ratios, gas hourly space velocities (GHSV) and reaction temperatures to identify the influence of operational variables. FESEM images indicate uniform particle size distribution for the sample synthesized with sol-gel method. It has been found that the sol-gel method has the potential to improve catalyst desired properties especially metal surface enrichment resulting in catalytic performance enhancement. The highest yield of products was obtained at 850 degrees C for both of the catalysts. During the 10 h stability test, CH4 and CO2 conversions gained higher values in the case of sol-gel made catalyst compared to impregnated one.

  6. Sono-synthesis and characterization of bimetallic Ni-Co/Al2O3-MgO nanocatalyst: Effects of metal content on catalytic properties and activity for hydrogen production via CO2 reforming of CH4.

    PubMed

    Abdollahifar, Mozaffar; Haghighi, Mohammad; Babaluo, Ali Akbar; Talkhoncheh, Saeed Khajeh

    2016-07-01

    Sono-dispersion of Ni, Co and Ni-Co over Al2O3-MgO with Al/Mg ratio of 1.5 was prepared and tested for dry reforming of methane. The samples were characterized by XRD, FESEM, PSD, EDX, TEM, BET and FTIR analyses. In order to assess the effect of ultrasound irradiation, Ni-Co/Al2O3-MgO with Co content of 8% prepared via sonochemistry and impregnation methods. The sono-synthesized sample showed better textural properties and higher activity than that of impregnated one. Comparison of XRD patterns indicated that the NiO peaks became broader by increasing Co content over the support. The FESEM images displayed the particles are small and well-dispersed as a result of sonochemistry method. Also, EDX analysis demonstrated better dispersion of Ni and Co as a result of sonochemistry method in confirmation of XRD analysis. The sono-synthesized Ni-Co/Al2O3-MgO as a superior nanocatalyst with Co content of 3% illustrates much higher conversions (97.5% and 99% for CH4 and CO2 at 850 °C), yields (94% and 96% for H2 and CO at 850 °C) and 0.97 of H2/CO molar ratio in all samples using an equimolar feed ratio at 850 °C. During the 1200 min stability test, H2/CO molar ratio remained constant for the superior nanocatalyst.

  7. Mapping methane from marine and terrestrial hydrocarbon seepage using AVIRIS

    NASA Astrophysics Data System (ADS)

    Thorpe, A. K.; Bradley, E. S.; Funk, C.; Roberts, D. A.; Leifer, I.; Dennison, P. E.; Margolis, J.

    2010-12-01

    Concentrations of atmospheric methane (CH4), a greenhouse gas at least 20 times more potent per molecule than carbon dioxide (CO2), have more than doubled in the last two centuries. Due to a lack of direct measurements of sources and sinks, the global methane budget is poorly constrained and emissions of this important greenhouse gas are often underestimated in climate models. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) recently mapped methane emissions from the Coal Oil Point (COP) marine seep fields, a concentrated geologic methane source (0.015 Tg yr-1 from ~3 km2) located offshore from Santa Barbara, CA using a residual-based approach (Roberts et al. 2010) and short-wave infrared band ratios (Bradley et al. submitted). In this study, an additional cluster-tuned matched filter technique adapted from Funk et al. 2001 detected methane anomalies for COP that closely matched previous results and were in agreement with sonar-based seep surveys and flux buoy data. This technique was also applied to AVIRIS data acquired over the La Brea Tar Pits in Los Angeles, CA, a region known for natural oil and methane seepage. Significant anomalies were identified for known methane sources close to the tar pits where pipes have been established to prevent dangerous methane buildup. Therefore, imaging spectrometry using sensors like AVIRIS and planned satellite sensors like HyspIRI has the potential to greatly improve high spatial resolution mapping of methane emissions, thereby better constraining regional methane sources.

  8. Seepage to Collection Gallery Near Seacoast

    NASA Astrophysics Data System (ADS)

    Hunt, B.

    1985-03-01

    Conformal mapping is used to obtain a solution for seepage to a collection gallery (a horizontal ditch or slotted pipe) that is parallel to a seacoast. The solution permits calculation of the gallery drawdown that is required to withdraw any given flow rate and also allows calculation of the maximum flow rate that can be abstracted without causing sea water intrusion. The results are applied to a numerical example.

  9. Inertial (non-Darcian) channeled seepage flow

    NASA Astrophysics Data System (ADS)

    Foda, Mostafa A.

    1994-10-01

    A slow wave solution is identified for an infinite elastic medium intersected by a two-dimensional fluid channel. Because the wave speed is much slower than the medium's elastic shear wave, the response in the elastic medium is governed by elastostatics. The inertia of the wave is essentially focused in the fluid channel. Furthermore, wave damping is caused by fluid viscous friction on the channel in an elastic solid. It is proposed that these solutions may also be used in the case of a granular porous medium. The seepage channels would then represent a network of preferential flow paths. Therefore we would allow, in this case, the channel porosity to be different from the average granular porosity. For a strongly channel seepage flow or for a low channel porosity the solution is shown to approach that of a single-channel solution, giving rise to a slow propagating wave mode. On the other hand, for weak channeling or nearly `homogeneous' seepage flow the solution is shown to reproduce Biot's (1956) critically damped wave of the second kind. It is proposed that the resonance observed by Foda and Tzang (1994) are in the form of these strongly channeled wave modes.

  10. Seepage Bifurcation as a Critical Process

    NASA Astrophysics Data System (ADS)

    Yi, R.; Rothman, D.

    2015-12-01

    Channel networks form beautiful and surprisingly intricate geometries, yet diligently evade comprehensive mathematical understanding. Work in recent years has shed light on this problem. Networks driven by seepage flow, in particular, have been shown to grow in a field that can be described by the Laplace equation, providing us with an understanding of valley growth and shape. However, the process by which such networks branch to form these ramified shapes is yet a mystery. We focus our attention on a highly ramified seepage valley network in Bristol, Florida. We study the behavior of flux to valley heads as a function of valley length, and use this result to motivate our discussion of branch formation. We then hypothesize that a critical groundwater flux demarcates a transition point where topographic diffusion is overcome by branching processes, and we present network-wide flux calculations, cosmogenic data, and simulation to support our claim. Our results ultimately suggest a mechanism for seepage bifurcation, and inform our understanding of pattern formation in river networks.

  11. Variability and comparison of hyporheic water temperatures and seepage fluxes in a small Atlantic salmon stream.

    PubMed

    Alexander, Matthew D; Caissie, Daniel

    2003-01-01

    Ground water discharge is often a significant factor in the quality of fish spawning and rearing habitat and for highly biologically productive streams. In the present study, water temperatures (stream and hyporheic) and seepage fluxes were used to characterize shallow ground water discharge and recharge within thestreambed of Catamaran Brook, a small Atlantic salmon (Salmo salar) stream in central New Brunswick, Canada. Three study sites were instrumented using a total of 10 temperature sensors and 18 seepage meters. Highly variable mean seepage fluxes, ranging from 1.7 x 10(-4) to 2.5 cm3 m(-2) sec(-1), and mean hyporheic water temperatures, ranging from 10.5 degrees to 18.0 degrees C, at depths of 20 to 30 cm in the streambed were dependent on streambed location (left versus right stream bank and site location) and time during the summer sampling season. Temperature data were usefulfor determining if an area of the streambed was under discharge (positive flux), recharge (negative flux), or parallel flow (no flux) conditions and seepage meters were used to directly measure the quantity of water flux. Hyporheic water temperature measurements and specific conductance measurements of the seepage meter sample water, mean values ranging from 68.8 to 157.9 microS/cm, provided additional data for determining flux sources. Three stream banks were consistently under discharge conditions, while the other three stream banks showed reversal from discharge to recharge conditions over the sampling season. Results indicate that the majority of the water collected in the seepage meters was composed of surface water. The data obtained suggests that even though a positive seepage flux is often interpreted as ground water discharge, this discharging water may be of stream water origin that has recently entered the hyporheic zone.The measurement of seepage flux in conjunction with hyporheic water temperature or other indicators of water origin should be considered when attempting to

  12. Functional Response of a Near-Surface Soil Microbial Community to a Simulated Underground CO2 Storage Leak

    PubMed Central

    Morales, Sergio E.; Holben, William E.

    2013-01-01

    Understanding the impacts of leaks from geologic carbon sequestration, also known as carbon capture and storage, is key to developing effective strategies for carbon dioxide (CO2) emissions management and mitigation of potential negative effects. Here, we provide the first report on the potential effects of leaks from carbon capture and storage sites on microbial functional groups in surface and near-surface soils. Using a simulated subsurface CO2 storage leak scenario, we demonstrate how CO2 flow upward through the soil column altered both the abundance (DNA) and activity (mRNA) of microbial functional groups mediating carbon and nitrogen transformations. These microbial responses were found to be seasonally dependent and correlated to shifts in atmospheric conditions. While both DNA and mRNA levels were affected by elevated CO2, they did not react equally, suggesting two separate mechanisms for soil microbial community response to high CO2 levels. The results did not always agree with previous studies on elevated atmospheric (rather than subsurface) CO2 using FACE (Free-Air CO2 Enrichment) systems, suggesting that microbial community response to CO2 seepage from the subsurface might differ from its response to atmospheric CO2 increases. PMID:24303067

  13. Adsorption of CO2 by alginate immobilized zeolite beads

    NASA Astrophysics Data System (ADS)

    Suratman, A.; Kunarti, E. S.; Aprilita, N. H.; Pamurtya, I. C.

    2017-03-01

    Immobilized zeolit in alginate beads for adsorption of CO2 was developed. Alginate immobilized zeolit beads was generated by dropping the mixture of Na-alginate and zeolite solution into Ca2+ solution. The adsorption efficacy such as the influence of contact time, mass of zeolite, flowrate of CO2, and mass of adsorbent was evaluated. The adsorption of CO2 onto alginate immobilized zeolit beads was investigated by performing both equilibrium and kinetic batch test. Bead was characterized by FTIR and SEM. Alginate immobilized zeolit beads demonstrated significantly higher sorption efficacy compared to plain alginate beads and zeolite with 0.25 mmol CO2 adsorbed /g adsorbent. Optimum condition was achieved with mass composition of alginate:zeolite (3:1), flowrate 50 mL/min for 20 minutes. The alginate immobilized zeolit beads showed that adsorption of CO2 followed Freundlich isotherm and pseudo second order kinetic model. Adsorption of CO2 onto alginate immobilized zeolite beads is a physisorption with adsorption energy of 6.37 kJ/mol. This results indicates that the alginate immobilized zeolit beads can be used as promising adsorbents for CO2.

  14. CO2-storage assessment and effective capacity in Algeria.

    PubMed

    Aktouf, Abdelouahab; Bentellis, Abdelhakim

    2016-01-01

    Deep saline aquifers widely distributed deep in the earth offer the greatest CO2 storage potential in all current geological CO2 storage approaches. The western region of the Saharan platform in Algeria includes several sedimentary basins characterized by a large production of dry gas with high CO2 rates sometimes exceeding 9 %. To reduce CO2 emissions, these basins were analyzed to identify those with the largest potential for the geological sequestration of CO2 (GSC). The evaluation methodology applied to determine the basin potential is based on qualitative geological and practical criteria to which we have assigned normalized numerical values. This evaluation method allows us to quantitatively compare and evaluate the basins in Algeria. Estimations of the CO2 storage capacities of several structures in the sedimentary Ahnet-Gourara Basin, which has the greatest potential for GSC, vary from 1 Gt to over 5 Gt. Based on cautious estimations, these geologic structures should be able to contain the entire volume of the CO2 emitted over the next three decades at least.

  15. High pressure studies on extended phases of CO2

    NASA Astrophysics Data System (ADS)

    Montoya, Javier A.; Lee, Mal-Soon; Scandolo, Sandro

    2010-03-01

    Recent findings have shown that the chemistry of CO2 at high pressure and temperature is richer than previously thought and that the activation of the C=O bond that can give origin to different forms of non-molecular CO2. Such findings may have important implications for the understanding of the Earth's deep carbon cycle and CO2 sequestration technologies. First principles simulations of CO2's electronic properties under different pressure and temperature conditions can constrain the thermodynamic phase diagram of CO2 and explore P-T conditions necessary for the C=O bond activation. We have shown that at about 50 GPa molecular CO2 can transform to a metastable amorphous form characterized by an almost equal proportion of three- and four-fold coordinated carbon atoms [1], while higher carbon coordination does not take place up to at least 900 GPa [2-3]. We have also found that doping with transition metals can reduce the activation barrier and transition pressure for the C=O bond activation in CO2 [4]. Our results suggest that pressure can radically alter the oxidation chemistry of carbon. [1] J. A. Montoya et al., PRL 100, 163002 (2008) [2] J. Sun et al., PNAS 106, 6077 (2009) [3] M-S. Lee, J. A. Montoya and S. Scandolo, PRB 79, 144102 (2009) [4] J. A. Montoya, R. Rousseau, and S. Scandolo, unpublished.

  16. CO2 Infrared Phonon Modes in Interstellar Ice Mixtures

    NASA Astrophysics Data System (ADS)

    Cooke, Ilsa R.; Fayolle, Edith C.; Öberg, Karin I.

    2016-11-01

    CO2 ice is an important reservoir of carbon and oxygen in star- and planet-forming regions. Together with water and CO, CO2 sets the physical and chemical characteristics of interstellar icy grain mantles, including desorption and diffusion energies for other ice constituents. A detailed understanding of CO2 ice spectroscopy is a prerequisite to characterize CO2 interactions with other volatiles both in interstellar ices and in laboratory experiments of interstellar ice analogs. We report laboratory spectra of the CO2 longitudinal optical (LO) phonon mode in pure CO2 ice and in CO2 ice mixtures with H2O, CO, and O2 components. We show that the LO phonon mode position is sensitive to the mixing ratio of various ice components of astronomical interest. In the era of the James Webb Space Telescope, this characteristic could be used to constrain interstellar ice compositions and morphologies. More immediately, LO phonon mode spectroscopy provides a sensitive probe of ice mixing in the laboratory and should thus enable diffusion measurements with higher precision than has been previously possible.

  17. Solution of AntiSeepage for Mengxi River Based on Numerical Simulation of Unsaturated Seepage

    PubMed Central

    Ji, Youjun; Zhang, Linzhi; Yue, Jiannan

    2014-01-01

    Lessening the leakage of surface water can reduce the waste of water resources and ground water pollution. To solve the problem that Mengxi River could not store water enduringly, geology investigation, theoretical analysis, experiment research, and numerical simulation analysis were carried out. Firstly, the seepage mathematical model was established based on unsaturated seepage theory; secondly, the experimental equipment for testing hydraulic conductivity of unsaturated soil was developed to obtain the curve of two-phase flow. The numerical simulation of leakage in natural conditions proves the previous inference and leakage mechanism of river. At last, the seepage control capacities of different impervious materials were compared by numerical simulations. According to the engineering actuality, the impervious material was selected. The impervious measure in this paper has been proved to be effectible by hydrogeological research today. PMID:24707199

  18. Molecular simulations of CO2 and mixed CH4-CO2 hydrates intercalated on smectites.

    NASA Astrophysics Data System (ADS)

    Martos-Villa, Rubén; Sainz-Díaz, C. Ignacio; Mata Campo, M. Pilar

    2013-04-01

    and behavior of hydrate-smectite complex. Characterization and better understanding of those deposits are necessary to develop CO2 storage as hydrates by methane replacement. Swelling clays usually contains multiple planes of weakly bonded H2O in the interlayer between the 2:1 (silicate) layers. Koster van Groos et al. (2009) synthesized a smectite-methane hydrate intercalate with d(001)=2.2 nm indicating the presence of one unit cell of methane hydrate crystal intercalated between the 2:1 layers of smectite. Due to the complexity of experimental studies with hydrates, Computational Mineralogy can be very helpful. In this study we compare the behavior of CO2 and mixed CH4-CO2 hydrates intercalated in montmorillonite and beidellite. Our results are in agreement with the d(001)=2.2 nm in both hydrates intercalated as crystal lattice. However, comparing mean square displacement (MSD) profiles from molecular dynamics simulations of H2O molecules in the hydrates, we found that hydrate crystal MSD show a typical solid profile without diffusion, while in the intercalates there is more diffusion of water molecules, hence CO2 and mixed CH4-CO2 hydrate structure is more flexible and stable in the smectite-hydrate complex. Authors are thankful to RNM-3581 CADHYS Project.

  19. Lasers utilizing CO2 isotopes

    NASA Astrophysics Data System (ADS)

    Pechenin, Yu V.; Domanov, M. S.

    1980-08-01

    The lasing spectra and energy characteristics were investigated for lasers operating with the isotopes 12C16O2, 13C16O2, 12C18O2, and 12C16O18O. It was found that the output power of a laser utilizing the CO2 isotopes was determined by the content of a particular isotope in the carbon dioxide gas. For equal enrichments, all the isotopes investigated, with the exception of 12C16O18O, gave comparable output powers. The unsaturated gains were identical for the most intense transitions of the symmetric molecules; the gain was a factor of two less for the asymmetric molecule. The gain rose linearly with increasing enrichment. The ultimate specific power output, given by the product of the saturation power density and the gain, was practically independent of the enrichment.

  20. CO2 capture using zeolite 13X prepared from bentonite

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Park, Dong-Wha; Ahn, Wha-Seung

    2014-02-01

    Zeolite 13X was prepared using bentonite as the raw material by alkaline fusion followed by a hydrothermal treatment without adding any extra silica or alumina sources. The prepared zeolite 13X was characterized by X-ray powder diffraction, N2-adsorption-desorption measurements, and scanning electron microscopy. The CO2 capture performance of the prepared zeolite 13X was examined under both static and flow conditions. The prepared zeolite 13X showed a high BET surface area of 688 m2/g with a high micropore volume (0.30 cm3/g), and exhibited high CO2 capture capacity (211 mg/g) and selectivity to N2 (CO2/N2 = 37) at 25 °C and 1 bar. In addition, the material showed fast adsorption kinetics, and stable CO2 adsorption-desorption recycling performance at both 25 and 200 °C.

  1. Uncertainty in gridded CO2 emissions estimates

    NASA Astrophysics Data System (ADS)

    Hogue, Susannah; Marland, Eric; Andres, Robert J.; Marland, Gregg; Woodard, Dawn

    2016-05-01

    We are interested in the spatial distribution of fossil-fuel-related emissions of CO2 for both geochemical and geopolitical reasons, but it is important to understand the uncertainty that exists in spatially explicit emissions estimates. Working from one of the widely used gridded data sets of CO2 emissions, we examine the elements of uncertainty, focusing on gridded data for the United States at the scale of 1° latitude by 1° longitude. Uncertainty is introduced in the magnitude of total United States emissions, the magnitude and location of large point sources, the magnitude and distribution of non-point sources, and from the use of proxy data to characterize emissions. For the United States, we develop estimates of the contribution of each component of uncertainty. At 1° resolution, in most grid cells, the largest contribution to uncertainty comes from how well the distribution of the proxy (in this case population density) represents the distribution of emissions. In other grid cells, the magnitude and location of large point sources make the major contribution to uncertainty. Uncertainty in population density can be important where a large gradient in population density occurs near a grid cell boundary. Uncertainty is strongly scale-dependent with uncertainty increasing as grid size decreases. Uncertainty for our data set with 1° grid cells for the United States is typically on the order of ±150%, but this is perhaps not excessive in a data set where emissions per grid cell vary over 8 orders of magnitude.

  2. Modeling Atmospheric CO2 Processes to Constrain the Missing Sink

    NASA Technical Reports Server (NTRS)

    Kawa, S. R.; Denning, A. S.; Erickson, D. J.; Collatz, J. C.; Pawson, S.

    2005-01-01

    We report on a NASA supported modeling effort to reduce uncertainty in carbon cycle processes that create the so-called missing sink of atmospheric CO2. Our overall objective is to improve characterization of CO2 source/sink processes globally with improved formulations for atmospheric transport, terrestrial uptake and release, biomass and fossil fuel burning, and observational data analysis. The motivation for this study follows from the perspective that progress in determining CO2 sources and sinks beyond the current state of the art will rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. The major components of this effort are: 1) Continued development of the chemistry and transport model using analyzed meteorological fields from the Goddard Global Modeling and Assimilation Office, with comparison to real time data in both forward and inverse modes; 2) An advanced biosphere model, constrained by remote sensing data, coupled to the global transport model to produce distributions of CO2 fluxes and concentrations that are consistent with actual meteorological variability; 3) Improved remote sensing estimates for biomass burning emission fluxes to better characterize interannual variability in the atmospheric CO2 budget and to better constrain the land use change source; 4) Evaluating the impact of temporally resolved fossil fuel emission distributions on atmospheric CO2 gradients and variability. 5) Testing the impact of existing and planned remote sensing data sources (e.g., AIRS, MODIS, OCO) on inference of CO2 sources and sinks, and use the model to help establish measurement requirements for future remote sensing instruments. The results will help to prepare for the use of OCO and other satellite data in a multi-disciplinary carbon data assimilation system for analysis and prediction of carbon cycle changes and carbodclimate interactions.

  3. 76 FR 15249 - Deferral for CO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ... area of land. Carbon can cycle fairly rapidly back to the atmosphere or it can remain stored on land... Deterioration (PSD) and Title V permitting requirements to biogenic carbon dioxide (CO 2 ) emissions from... Information CFR Code of Federal Regulations CH 4 methane CO 2 Carbon dioxide CO 2 e Carbon dioxide...

  4. Seepage through a hazardous-waste trench cover

    USGS Publications Warehouse

    Healy, R.W.

    1989-01-01

    Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216 mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest rates occurred along the edge of the cover, where seepage was highly episodic, with 84% of the total there being traced to wetting fronts from 28 individual storms. Limitations of the zero-flux-plane method were severe enough for the method to be judged inappropriate for use in this study.Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest

  5. Savannah River Laboratory Seepage Basins: Waste site assessment report

    SciTech Connect

    Haselow, J.S.; Looney, B.B.; Nichols, R.L.

    1989-09-05

    This Waste Site Assessment for the SRL Seepage Basins is the second in a series of documents being prepared to support development of an appropriate closure plan for these basins. The closure of these basins will be designed to provide protection to human health and the environment and to meet the provisions of the Consent Decree. A Technical Data Summary for these basins has already been submitted as part of the Consent Decree. This Site Assessment Report includes a waste site characterization, and a discussion of closure options for the basins. A closure option is recommended in this report, but details of the recommended closure are not provided in this report since they will be provided in a subsequent closure plan. The closure plan is the third document required under the Consent Decree. 18 refs., 16 figs., 10 tabs.

  6. Ground-based thermal imaging of groundwater flow processes at the seepage face

    NASA Astrophysics Data System (ADS)

    Deitchman, Richard S.; Loheide, Steven P.

    2009-07-01

    There is no existing method to quantitatively image groundwater processes along a seepage face. Thus, it is often difficult to quantify the magnitude and spatial variability of groundwater flux. The objective of this work is to assess the use of ground-based thermal remote sensing for fine-scale mapping of groundwater discharge and for locating the water table position along a stream bank seepage face. Seepage faces are poorly understood and often neglected in regional hydrologic studies though they likely exert significant influence on hydrologic and ecologic processes in riparian zones. Although the importance of riparian areas is broadly recognized, our ability to quantify hydrologic, ecologic and biogeochemical processes and ecosystem services is hampered by our inability to characterize spatially variable processes such as groundwater discharge. This work employs a new, transferable, non-invasive method that uses heat as a natural tracer to image spatially-variable groundwater flow processes and distinguish between focused and diffuse groundwater discharge to the surface. We report, for the first time, that thermal remote sensing of groundwater at the seepage face provides indirect imaging of both the saturated zone-unsaturated zone transition and groundwater flux at the centimeter scale, offering insight into flow heterogeneity.

  7. Natural convection in tunnels at Yucca Mountain and impact on drift seepage

    SciTech Connect

    Halecky, N.; Birkholzer, J.T.; Peterson, P.

    2010-04-15

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock in the drift center to the drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water-induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  8. Structurally simple complexes of CO2.

    PubMed

    Murphy, Luke J; Robertson, Katherine N; Kemp, Richard A; Tuononen, Heikki M; Clyburne, Jason A C

    2015-03-07

    The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added products, particularly transportation fuels or fuel precursors. Implementation on a large scale could help to drastically reduce CO2 concentrations in the atmosphere. However, literature examples of weakly bonded complexes of CO2 are relatively few and true coordination complexes to a 'naked' CO2 fragment are nearly unheard of. In this review article, a variety of complexes of CO2 featuring diverse binding modes and reactivity will be examined. Topics covered include: (A) inclusion complexes of CO2 in porous materials. (B) Zwitterionic carbamates produced from the reaction of CO2 with polyamines. (C) Carbamate salts produced from reaction of CO2 with two equivalents of an amine. (D) Insertion products of CO2 into acid-base adducts (e.g., metal complexes). (E) Lewis acid-base activated CO2, such as frustrated Lewis pair complexes. (F) Simple base-CO2 adducts, wherein the base-CO2 bond is the only interaction formed. Complexes in the last category are of particular interest, and include imidazol-2-carboxylates (N-heterocyclic carbene adducts of CO2) as well as a few other examples that lie outside NHC chemistry.

  9. The Wettability of Shale by CO2 and Its Impact on Geologic CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Guiltinan, E. J.; Cardenas, M. B.; Espinoza, D. N.; Yoon, H.; Dewers, T. A.

    2015-12-01

    The geologic sequestration of CO2 is widely considered as a potential solution for decreasing anthropogenic atmospheric CO2 emissions. Wettability of fluids within reservoir materials is a critical factor in determining the efficiency of structural and residual trapping, two major mechanisms of geologic sequestration. Individual reservoir minerals are often targeted for wettability studies. Current practice applies these results, recorded under laboratory conditions, to in-situ reservoir rock; however the wide variety of measured contact angles reported in the literature calls this practice into question. To address these issues and to study the wettability of shale caprock, resedimentation techniques are employed. These techniques allow for the creation of synthetic shales with controlled, homogeneous mineralogies. In addition, the systematic variation of the mineralogy allows for the characterization of shale wettability as a function of mineralogical composition. A novel design has been developed and used to conduct wettability experiments at reservoir conditions using high resolution X-ray computer tomography. Using this technique the wettability of resedimented shales and natural shales are compared at different reservoir conditions. Next, Lattice Boltzmann modelling methods are used to simulate capillary entry pressure into a shale capillary. Adhesion parameters along the wall are tuned to the results of the synthetic shales and heterogeneity is incorporated to estimate the capillary entry pressure into a natural shale. Understanding the mineralogical components of shale wetting allows for the prediction of capillary entry pressure based on shale mineralogy which can be used to help select secure CO2 storage sites.

  10. Enhanced Molecular Sieve CO2 Removal Evaluation

    NASA Technical Reports Server (NTRS)

    Rose, Susan; ElSherif, Dina; MacKnight, Allen

    1996-01-01

    The objective of this research is to quantitatively characterize the performance of two major types of molecular sieves for two-bed regenerative carbon dioxide removal at the conditions compatible with both a spacesuit and station application. One sorbent is a zeolite-based molecular sieve that has been substantially improved over the materials used in Skylab. The second sorbent is a recently developed carbon-based molecular sieve. Both molecular sieves offer the potential of high payoff for future manned missions by reducing system complexity, weight (including consumables), and power consumption in comparison with competing concepts. The research reported here provides the technical data required to improve CO2 removal systems for regenerative life support systems for future IVA and EVA missions.

  11. Forest succession at elevated CO2

    SciTech Connect

    Clark, James S.; Schlesinger, William H.

    2002-02-01

    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response.

  12. Isotopic CO2 Instrumentation for UAV Measurements

    NASA Astrophysics Data System (ADS)

    Gomez, A.; Silver, J.

    2013-12-01

    Carbon dioxide is the largest component of anthroprogenic green house gas emissions. Knowing atmospheric 13CO2/12CO2 ratios precisely is important for understanding biogenic and anthroprogenic sources and sinks for carbon. Instrumentation mounted on UAV aircraft would enable important spatial isotopic CO2 information. However, current isotopic CO2 instrumentation have unfavorable attributes for UAV use, such as high power requirements, high cost, high weight, and large size. Here we present the early development of a compact isotopic CO2 instrument that is designed to nullify effects of pressure, temperature and moisture, and will ultimately be suitable for UAV deployment.

  13. Aminosilicone solvents for CO(2) capture.

    PubMed

    Perry, Robert J; Grocela-Rocha, Teresa A; O'Brien, Michael J; Genovese, Sarah; Wood, Benjamin R; Lewis, Larry N; Lam, Hubert; Soloveichik, Grigorii; Rubinsztajn, Malgorzata; Kniajanski, Sergei; Draper, Sam; Enick, Robert M; Johnson, J Karl; Xie, Hong-bin; Tapriyal, Deepak

    2010-08-23

    This work describes the first report of the use of an aminosilicone solvent mix for the capture of CO(2). To maintain a liquid state, a hydroxyether co-solvent was employed which allowed enhanced physisorption of CO(2) in the solvent mixture. Regeneration of the capture solvent system was demonstrated over 6 cycles and absorption isotherms indicate a 25-50 % increase in dynamic CO(2) capacity over 30 % MEA. In addition, proof of concept for continuous CO(2) absorption was verified. Additionally, modeling to predict heats of reaction of aminosilicone solvents with CO(2) was in good agreement with experimental results.

  14. Selecting CO2 Sources for CO2 Utilization by Environmental-Merit-Order Curves.

    PubMed

    von der Assen, Niklas; Müller, Leonard J; Steingrube, Annette; Voll, Philip; Bardow, André

    2016-02-02

    Capture and utilization of CO2 as alternative carbon feedstock for fuels, chemicals, and materials aims at reducing greenhouse gas emissions and fossil resource use. For capture of CO2, a large variety of CO2 sources exists. Since they emit much more CO2 than the expected demand for CO2 utilization, the environmentally most favorable CO2 sources should be selected. For this purpose, we introduce the environmental-merit-order (EMO) curve to rank CO2 sources according to their environmental impacts over the available CO2 supply. To determine the environmental impacts of CO2 capture, compression and transport, we conducted a comprehensive literature study for the energy demands of CO2 supply, and constructed a database for CO2 sources in Europe. Mapping these CO2 sources reveals that CO2 transport distances are usually small. Thus, neglecting transport in a first step, we find that environmental impacts are minimized by capturing CO2 first from chemical plants and natural gas processing, then from paper mills, power plants, and iron and steel plants. In a second step, we computed regional EMO curves considering transport and country-specific impacts for energy supply. Building upon regional EMO curves, we identify favorable locations for CO2 utilization with lowest environmental impacts of CO2 supply, so-called CO2 oases.

  15. Seepage Reduction from Unlined Irrigation Canals: Water Quality and Seepage Reduction Effectiveness

    NASA Astrophysics Data System (ADS)

    Susfalk, R. B.; Epstein, B. J.; Schmidt, M.; Goreham, J.; Fitzgerald, B.; Young, M. H.; Martin, C.; Swihart, J.; Smith, D.

    2006-12-01

    Polyacrylamide is a class of long-chain synthetic polymers that is used extensively in food packaging, paper manufacturing, wastewater treatment, and as a soil amendment to reduce erosion. More recently, linear, anionic polyacrylamides (LA-PAM) have been used to reduce seepage from unlined irrigation canals in the western United States. A diverse set of experiments spanning multiple scales has been initiated to understand the efficacy of LA-PAM usage in canal environments. The physical application of granular LA-PAM to flowing canals is straightforward. However, granular PAM requires time to hydrate and react with sediment suspended in the water column, complicating the targeting of a specific canal reach for treatment. Factors that influence PAM's ability to reduce seepage will be discussed, and can include: water temperature, water velocity, and the cation balance and suspended sediment concentration in the canal water. The application method and mass of PAM that are applied are also important considerations. If the ability of PAM to form flocs with suspended sediment is overestimated, PAM will travel further downstream, potentially having an adverse impact on water quality and/or ecology. Negative impacts include livestock drinking out of the canal, the unintentional reduction of seepage water feeding adjacent wetlands or sensitive areas, and impacts on receiving waters. A combination of results from working canals and small scale, artificial Test Troughs will be used to address the impacts that different LA-PAM applications can have on water quality and seepage reduction effectiveness.

  16. Microbial Growth under Supercritical CO2

    PubMed Central

    Peet, Kyle C.; Freedman, Adam J. E.; Hernandez, Hector H.; Britto, Vanya; Boreham, Chris; Ajo-Franklin, Jonathan B.

    2015-01-01

    Growth of microorganisms in environments containing CO2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO2 (scCO2) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO2. Analysis of 16S rRNA genes from scCO2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO2, suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO2 in the deep subsurface. PMID:25681188

  17. Microbial growth under supercritical CO2.

    PubMed

    Peet, Kyle C; Freedman, Adam J E; Hernandez, Hector H; Britto, Vanya; Boreham, Chris; Ajo-Franklin, Jonathan B; Thompson, Janelle R

    2015-04-01

    Growth of microorganisms in environments containing CO2 above its critical point is unexpected due to a combination of deleterious effects, including cytoplasmic acidification and membrane destabilization. Thus, supercritical CO2 (scCO2) is generally regarded as a sterilizing agent. We report isolation of bacteria from three sites targeted for geologic carbon dioxide sequestration (GCS) that are capable of growth in pressurized bioreactors containing scCO2. Analysis of 16S rRNA genes from scCO2 enrichment cultures revealed microbial assemblages of varied complexity, including representatives of the genus Bacillus. Propagation of enrichment cultures under scCO2 headspace led to isolation of six strains corresponding to Bacillus cereus, Bacillus subterraneus, Bacillus amyloliquefaciens, Bacillus safensis, and Bacillus megaterium. Isolates are spore-forming, facultative anaerobes and capable of germination and growth under an scCO2 headspace. In addition to these isolates, several Bacillus type strains grew under scCO2, suggesting that this may be a shared feature of spore-forming Bacillus spp. Our results provide direct evidence of microbial activity at the interface between scCO2 and an aqueous phase. Since microbial activity can influence the key mechanisms for permanent storage of sequestered CO2 (i.e., structural, residual, solubility, and mineral trapping), our work suggests that during GCS microorganisms may grow and catalyze biological reactions that influence the fate and transport of CO2 in the deep subsurface.

  18. Amine scrubbing for CO2 capture.

    PubMed

    Rochelle, Gary T

    2009-09-25

    Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas and hydrogen since 1930. It is a robust technology and is ready to be tested and used on a larger scale for CO2 capture from coal-fired power plants. The minimum work requirement to separate CO2 from coal-fired flue gas and compress CO2 to 150 bar is 0.11 megawatt-hours per metric ton of CO2. Process and solvent improvements should reduce the energy consumption to 0.2 megawatt-hour per ton of CO2. Other advanced technologies will not provide energy-efficient or timely solutions to CO2 emission from conventional coal-fired power plants.

  19. Attention turns to naturally occurring methane seepage

    NASA Astrophysics Data System (ADS)

    Kvenvolden, Keith A.; Lorenson, Thomas D.; Reeburgh, William S.

    Methane is the most abundant organic compound in the Earth's atmosphere. As a powerful greenhouse gas, it has implications for global climate change. Sources of methane to the atmosphere are varied. Depending on the source, methane can contain either modern or ancient carbon. Methane exiting from swamps and wetlands contains modern carbon, whereas methane leaking from petroleum reservoirs contains ancient carbon. The total annual source of methane to the atmosphere has been constrained to about 540 teragrams (Tg) per year “Cicerone and Oremland, 1988”. Notably absent from any identified sources is the contribution of geologically sourced methane from naturally occurring seepage.

  20. Fourier Transform Microwave Spectra of CO{2}-ETHYLENE Sulfide, CO{2}-ETHYLENE Oxide and CO{2}-PROPYLENE Oxide Complexes

    NASA Astrophysics Data System (ADS)

    Orita, Yukari; Kawashima, Yoshiyuki; Hirota, Eizi

    2010-06-01

    We have previously examined the difference in roles of O and S in structure and dynamics of the CO-ethylene oxide (EO) and CO-ethylene sulfide (ES) complexes. We have extended the investigation to CO{2}-EO and CO{2}-ES for comparison. We have also observed the CO{2}-propylene oxide (PO) complex, which is an important intermediate in the reaction of PO with CO{2} leading to polycarbonate. Both a-type and b-type transitions were observed for the CO{2}-EO and CO{2}-ES, but no c-type transitions were observed at all. We also detected the {34}S and {13}C isotopic species in natural abundance and the species containing {18}OCO and C{18}O% {2}, which were synthesized by burning paper in an {18}O{2} and{% 16}O{2} mixture. By analyzing the observed spectra we concluded the CO{2} moiety of CO{2}-EO and CO{2}-ES located in a plane % prependicular to the three-membered ring and bisecting the COC or CSC angle of EO or ES, respectively, as in the case of CO-EO and CO-ES complexes. An % ab initio MO calculation at the level of MP2/6-311G(d, p) yielded an optimized structure in good agreement with the experimental result. We have derived from the observed spectra the distance, the stretching force constant, and the binding energy of the bonds between the constituents of the CO{2}-EO and CO{2}-ES complexes and have found that the distances of the two complexes were shorter by 0.2Å than those in CO-EO and CO-ES, respectively, and that the intermolecular bonds were two times stronger in the CO{2} complexes than in the corresponding CO complexes. We have concluded from the observed spectra that the CO{2} moiety in CO{2}-PO is located on the PO three-membered ring plane opposite to the methyl group. The constituents in CO{2}-PO were more weakly bound than those in CO{2}-EO and CO{2}-ES. S. Sato, Y. Kawashima, Y. Tatamitani, and E. Hirota, 63rd International Symposium on Molecular Spectroscopy, WF05 (2008).

  1. Greenhouse gases generated from the anaerobic biodegradation of natural offshore asphalt seepages in southern California

    USGS Publications Warehouse

    Lorenson, T.D.; Wong, Florence L.; Dartnell, Peter; Sliter, Ray W.

    2014-01-01

    Significant offshore asphaltic deposits with active seepage occur in the Santa Barbara Channel offshore southern California. The composition and isotopic signatures of gases sampled from the oil and gas seeps reveal that the coexisting oil in the shallow subsurface is anaerobically biodegraded, generating CO2 with secondary CH4 production. Biomineralization can result in the consumption of as much as 60% by weight of the original oil, with 13C enrichment of CO2. Analyses of gas emitted from asphaltic accumulations or seeps on the seafloor indicate up to 11% CO2 with 13C enrichment reaching +24.8‰. Methane concentrations range from less than 30% up to 98% with isotopic compositions of –34.9 to –66.1‰. Higher molecular weight hydrocarbon gases are present in strongly varying concentrations reflecting both oil-associated gas and biodegradation; propane is preferentially biodegraded, resulting in an enriched 13C isotopic composition as enriched as –19.5‰. Assuming the 132 million barrels of asphaltic residues on the seafloor represent ~40% of the original oil volume and mass, the estimated gas generated is 5.0×1010 kg (~76×109 m3) CH4 and/or 1.4×1011 kg CO2 over the lifetime of seepage needed to produce the volume of these deposits. Geologic relationships and oil weathering inferences suggest the deposits are of early Holocene age or even younger. Assuming an age of ~1,000 years, annual fluxes are on the order of 5.0×107 kg (~76×106 m3) and/or 1.4×108 kg for CH4 and CO2, respectively. The daily volumetric emission rate (2.1×105 m3) is comparable to current CH4 emission from Coal Oil Point seeps (1.5×105 m3/day), and may be a significant source of both CH4 and CO2 to the atmosphere provided that the gas can be transported through the water column.

  2. Greenhouse gases generated from the anaerobic biodegradation of natural offshore asphalt seepages in southern California

    NASA Astrophysics Data System (ADS)

    Lorenson, Thomas D.; Wong, Florence L.; Dartnell, Peter; Sliter, Ray W.

    2014-06-01

    Significant offshore asphaltic deposits with active seepage occur in the Santa Barbara Channel offshore southern California. The composition and isotopic signatures of gases sampled from the oil and gas seeps reveal that the coexisting oil in the shallow subsurface is anaerobically biodegraded, generating CO2 with secondary CH4 production. Biomineralization can result in the consumption of as much as 60% by weight of the original oil, with 13C enrichment of CO2. Analyses of gas emitted from asphaltic accumulations or seeps on the seafloor indicate up to 11% CO2 with 13C enrichment reaching +24.8‰. Methane concentrations range from less than 30% up to 98% with isotopic compositions of -34.9 to -66.1‰. Higher molecular weight hydrocarbon gases are present in strongly varying concentrations reflecting both oil-associated gas and biodegradation; propane is preferentially biodegraded, resulting in an enriched 13C isotopic composition as enriched as -19.5‰. Assuming the 132 million barrels of asphaltic residues on the seafloor represent ~40% of the original oil volume and mass, the estimated gas generated is 5.0×1010 kg (~76×109 m3) CH4 and/or 1.4×1011 kg CO2 over the lifetime of seepage needed to produce the volume of these deposits. Geologic relationships and oil weathering inferences suggest the deposits are of early Holocene age or even younger. Assuming an age of ~1,000 years, annual fluxes are on the order of 5.0×107 kg (~76×106 m3) and/or 1.4×108 kg for CH4 and CO2, respectively. The daily volumetric emission rate (2.1×105 m3) is comparable to current CH4 emission from Coal Oil Point seeps (1.5×105 m3/day), and may be a significant source of both CH4 and CO2 to the atmosphere provided that the gas can be transported through the water column.

  3. Earth's Atmospheric CO2 Saturated IR Absorption

    NASA Astrophysics Data System (ADS)

    Wall, Ernst

    2008-10-01

    Using the on-line SpectraCalc IR absorption simulator, the amount of IR absorption by the 15 μ line of the current atmospheric CO2 was obtained and compared with that of twice the amount of CO2. The simulation required a fixed density equivalent for the atmospheric path length. This was obtained by numerically integrating the NOAA Standard Atmospheric model. While the current line is saturated, doubling the CO2 will cause a slight width increase. Using this and the blackbody radiation curve plus considering the effects of water vapor, the temperature rise of the Earth will be less than 2.5 deg. C. Integrating a NASA Martian atmospheric model, we find that the Martian atmosphere has 45 times more CO2 to penetrate than Earth, and yet, the Martian diurnal temperature swings exceed those of the Sahara desert. I.e., large amounts of CO2 alone do not necessarily cause planetary warming. As the oceans warm from any cause, more CO2 is boiled out, but if they cool, they will absorb more CO2 just as a carbonated drink does, so that temperature and CO2 density will correlate. It is to be noted that the Earth's known petroleum reserves contain only enough CO2 to increase the atmospheric CO2 by some 15%.

  4. CO2 transport over complex terrain

    USGS Publications Warehouse

    Sun, Jielun; Burns, Sean P.; Delany, A.C.; Oncley, S.P.; Turnipseed, A.A.; Stephens, B.B.; Lenschow, D.H.; LeMone, M.A.; Monson, Russell K.; Anderson, D.E.

    2007-01-01

    CO2 transport processes relevant for estimating net ecosystem exchange (NEE) at the Niwot Ridge AmeriFlux site in the front range of the Rocky Mountains, Colorado, USA, were investigated during a pilot experiment. We found that cold, moist, and CO2-rich air was transported downslope at night and upslope in the early morning at this forest site situated on a ???5% east-facing slope. We found that CO2 advection dominated the total CO2 transport in the NEE estimate at night although there are large uncertainties because of partial cancellation of horizontal and vertical advection. The horizontal CO2 advection captured not only the CO2 loss at night, but also the CO2 uptake during daytime. We found that horizontal CO2 advection was significant even during daytime especially when turbulent mixing was not significant, such as in early morning and evening transition periods and within the canopy. Similar processes can occur anywhere regardless of whether flow is generated by orography, synoptic pressure gradients, or surface heterogeneity as long as CO2 concentration is not well mixed by turbulence. The long-term net effect of all the CO2 budget terms on estimates of NEE needs to be investigated. ?? 2007 Elsevier B.V. All rights reserved.

  5. Covalent Organic Frameworks for CO2 Capture.

    PubMed

    Zeng, Yongfei; Zou, Ruqiang; Zhao, Yanli

    2016-04-20

    As an emerging class of porous crystalline materials, covalent organic frameworks (COFs) are excellent candidates for various applications. In particular, they can serve as ideal platforms for capturing CO2 to mitigate the dilemma caused by the greenhouse effect. Recent research achievements using COFs for CO2 capture are highlighted. A background overview is provided, consisting of a brief statement on the current CO2 issue, a summary of representative materials utilized for CO2 capture, and an introduction to COFs. Research progresses on: i) experimental CO2 capture using different COFs synthesized based on different covalent bond formations, and ii) computational simulation results of such porous materials on CO2 capture are summarized. Based on these experimental and theoretical studies, careful analyses and discussions in terms of the COF stability, low- and high-pressure CO2 uptake, CO2 selectivity, breakthrough performance, and CO2 capture conditions are provided. Finally, a perspective and conclusion section of COFs for CO2 capture is presented. Recent advancements in the field are highlighted and the strategies and principals involved are discussed.

  6. Energyless CO2 Absorption, Generation, and Fixation Using Atmospheric CO2.

    PubMed

    Inagaki, Fuyuhiko; Okada, Yasuhiko; Matsumoto, Chiaki; Yamada, Masayuki; Nakazawa, Kenta; Mukai, Chisato

    2016-01-01

    From an economic and ecological perspective, the efficient utilization of atmospheric CO2 as a carbon resource should be a much more important goal than reducing CO2 emissions. However, no strategy to harvest CO2 using atmospheric CO2 at room temperature currently exists, which is presumably due to the extremely low concentration of CO2 in ambient air (approximately 400 ppm=0.04 vol%). We discovered that monoethanolamine (MEA) and its derivatives efficiently absorbed atmospheric CO2 without requiring an energy source. We also found that the absorbed CO2 could be easily liberated with acid. Furthermore, a novel CO2 generator enabled us to synthesize a high value-added material (i.e., 2-oxazolidinone derivatives based on the metal catalyzed CO2-fixation at room temperature) from atmospheric CO2.

  7. Exogenously produced CO2 doubles the CO2 efflux from three north temperate lakes

    NASA Astrophysics Data System (ADS)

    Wilkinson, Grace M.; Buelo, Cal D.; Cole, Jonathan J.; Pace, Michael L.

    2016-03-01

    It is well established that lakes are typically sources of CO2 to the atmosphere. However, it remains unclear what portion of CO2 efflux is from endogenously processed organic carbon or from exogenously produced CO2 transported into lakes. We estimated high-frequency CO2 and O2 efflux from three north temperate lakes in summer to determine the proportion of the total CO2 efflux that was exogenously produced. Two of the lakes were amended with nutrients to experimentally enhance endogenous CO2 uptake. In the unfertilized lake, 50% of CO2 efflux was from exogenous sources and hydrology had a large influence on efflux. In the fertilized lakes, endogenous CO2 efflux was negative (into the lake) yet exogenous CO2 made the lakes net sources of CO2 to the atmosphere. Shifts in hydrologic regimes and nutrient loading have the potential to change whether small lakes act primarily as reactors or vents in the watershed.

  8. Uncertainty in gridded CO2 emissions estimates

    DOE PAGES

    Hogue, Susannah; Marland, Eric; Andres, Robert J.; ...

    2016-05-19

    We are interested in the spatial distribution of fossil-fuel-related emissions of CO2 for both geochemical and geopolitical reasons, but it is important to understand the uncertainty that exists in spatially explicit emissions estimates. Working from one of the widely used gridded data sets of CO2 emissions, we examine the elements of uncertainty, focusing on gridded data for the United States at the scale of 1° latitude by 1° longitude. Uncertainty is introduced in the magnitude of total United States emissions, the magnitude and location of large point sources, the magnitude and distribution of non-point sources, and from the use ofmore » proxy data to characterize emissions. For the United States, we develop estimates of the contribution of each component of uncertainty. At 1° resolution, in most grid cells, the largest contribution to uncertainty comes from how well the distribution of the proxy (in this case population density) represents the distribution of emissions. In other grid cells, the magnitude and location of large point sources make the major contribution to uncertainty. Uncertainty in population density can be important where a large gradient in population density occurs near a grid cell boundary. Uncertainty is strongly scale-dependent with uncertainty increasing as grid size decreases. In conclusion, uncertainty for our data set with 1° grid cells for the United States is typically on the order of ±150%, but this is perhaps not excessive in a data set where emissions per grid cell vary over 8 orders of magnitude.« less

  9. The NASA OCO-2 CO2 Directed Satellite Mission

    NASA Technical Reports Server (NTRS)

    Crisp, David

    2011-01-01

    NASA's Orbiting Carbon Observatory (OCO) was designed to provide the measurements needed to estimate the atmospheric CO2 dry air mole fraction (XCO2) with the sensitivity, accuracy, and sampling density needed to quantify regional scale carbon sources and sinks over the globe and characterize their behavior over the annual cycle.

  10. CO2 sequestration: Storage capacity guideline needed

    USGS Publications Warehouse

    Frailey, S.M.; Finley, R.J.; Hickman, T.S.

    2006-01-01

    Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

  11. R&D100: CO2 Memzyme

    SciTech Connect

    Rempe, Susan; Brinker, Jeff; Jiang, Ying-Bing; Vanegas, Juan

    2015-11-19

    By combining a water droplet loaded with CO2 enzymes in an ultrathin nanopore on a flexible substrate, researchers at Sandia National Laboratories realized the first technology that meets and exceeds DOE targets for cost-effective CO2 capture. When compared with the nearest membrane competitor, this technology delivers a three times permeation rate, twenty times higher selectivity, and ten time lower fabrication cost. The CO2 Memzyme has the potential to remove 90% of CO2 emissions and is forecasted to save the U.S. coal industry $90 billion a year compared to conventional technology.

  12. Synthetic biology for CO2 fixation.

    PubMed

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO2) into fuels and chemicals is a potential approach to reduce CO2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO2-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO2-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO2-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO2-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO2.

  13. CO2 capture in different carbon materials.

    PubMed

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya

    2012-07-03

    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  14. R&D100: CO2 Memzyme

    ScienceCinema

    Rempe, Susan; Brinker, Jeff; Jiang, Ying-Bing; Vanegas, Juan

    2016-07-12

    By combining a water droplet loaded with CO2 enzymes in an ultrathin nanopore on a flexible substrate, researchers at Sandia National Laboratories realized the first technology that meets and exceeds DOE targets for cost-effective CO2 capture. When compared with the nearest membrane competitor, this technology delivers a three times permeation rate, twenty times higher selectivity, and ten time lower fabrication cost. The CO2 Memzyme has the potential to remove 90% of CO2 emissions and is forecasted to save the U.S. coal industry $90 billion a year compared to conventional technology.

  15. CO2 MITIGATION VIA ACCELERATED LIMESTONE WEATHERING

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K G

    2004-02-27

    The climate and environmental impacts of our current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. As part of this effort, various means of capturing and storing CO2 generated from fossil-fuel-based energy production are being investigated. One of the proposed methods involves a geochemistry-based capture and sequestration process that hydrates point-source, waste CO2 with water to produce a carbonic acid solution. This in turn is reacted and neutralized with limestone, thus converting the original CO2 gas to calcium bicarbonate in solution, the overall reaction being:

  16. Quantitative evaluation of thin-layer thickness and CO2 mass utilizing seismic complex decomposition at the Ketzin CO2 storage site, Germany

    NASA Astrophysics Data System (ADS)

    Huang, Fei; Juhlin, Christopher; Han, Li; Kempka, Thomas; Lüth, Stefan; Zhang, Fengjiao

    2016-10-01

    Determining thin layer thickness is very important for reservoir characterization and CO2 quantification. Given its high time-frequency resolution and robustness, the complex spectral decomposition method was applied on time-lapse 3-D seismic data from the Ketzin pilot site for CO2 storage to evaluate the frequency-dependent characteristics of thin layers at the injection level. Higher temporal resolution and more stratigraphic details are seen in the all-frequency and monochromatic reflectivity amplitude sections obtained by complex spectral decomposition compared to the stacked sections. The mapped geologic discontinuities within the reservoir are consistent with the preferred orientation of CO2 propagation. Tuning frequency mapping shows the thicknesses of the reservoir sandstone and gaseous CO2 is consistent with the measured thickness of the sandstone unit from well logging. An attempt to discriminate between pressure effects and CO2 saturation using the extracted tuning frequency indicates that CO2 saturation is the main contributor to the amplitude anomaly at the Ketzin site. On the basis of determined thickness of gaseous CO2 in the reservoir, quantitative analysis of the amount of CO2 was performed and shows a discrepancy between the injected and calculated CO2 mass. This may be explained by several uncertainties, like structural reservoir heterogeneity, a limited understanding of the complex subsurface conditions, error of determined tuning frequency, the presence of ambient noise and ongoing CO2 dissolution.

  17. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    Oil sands comprise 30% of the world's oil reserves and the crude oil reserves in Canada's oil sands deposits are second only to Saudi Arabia. The extraction and processing of oil sands is much more challenging than for light sweet crude oils because of the high viscosity of the bitumen contained within the oil sands and because the bitumen is mixed with sand and contains chemical impurities such as sulphur. Despite these challenges, the importance of oil sands is increasing in the energy market. To our best knowledge this is the first peer-reviewed study to characterize volatile organic compounds (VOCs) emitted from Alberta's oil sands mining sites. We present high-precision gas chromatography measurements of 76 speciated C2-C10 VOCs (alkanes, alkenes, alkynes, cycloalkanes, aromatics, monoterpenes, oxygenated hydrocarbons, halocarbons and sulphur compounds) in 17 boundary layer air samples collected over surface mining operations in northeast Alberta on 10 July 2008, using the NASA DC-8 airborne laboratory as a research platform. In addition to the VOCs, we present simultaneous measurements of CO2, CH4, CO, NO, NO2, NOy, O3 and SO2, which were measured in situ aboard the DC-8. Carbon dioxide, CH4, CO, NO, NO2, NOy, SO2 and 53 VOCs (e.g., non-methane hydrocarbons, halocarbons, sulphur species) showed clear statistical enhancements (1.1-397×) over the oil sands compared to local background values and, with the exception of CO, were greater over the oil sands than at any other time during the flight. Twenty halocarbons (e.g., CFCs, HFCs, halons, brominated species) either were not enhanced or were minimally enhanced (<10%) over the oil sands. Ozone levels remained low because of titration by NO, and three VOCs (propyne, furan, MTBE) remained below their 3 pptv detection limit throughout the flight. Based on their correlations with one another, the compounds emitted by the oil sands industry fell into two groups: (1) evaporative emissions from the oil sands and its

  18. Environmental considerations for subseabed geological storage of CO2: A review

    NASA Astrophysics Data System (ADS)

    Carroll, A. G.; Przeslawski, R.; Radke, L. C.; Black, J. R.; Picard, K.; Moreau, J. W.; Haese, R. R.; Nichol, S.

    2014-07-01

    Many countries are now using or investigating offshore geological storage of CO2 as a means to reduce atmospheric CO2 emissions. Although associated research often focuses on deep-basin geology (e.g. seismic, geomagnetics), environmental data on the seabed and shallow subseabed is also crucial to (1) detect and characterise potential indicators of fluid seeps and their potential connectivity to targeted storage reserves, (2) obtain baseline environmental data for use in future monitoring, and (3) acquire information to facilitate an improved understanding of ecosystem processes for use in impact prediction. This study reviews the environmental considerations, including potential ecological impacts, associated with subseabed geological storage of CO2. Due to natural variations in CO2 levels in seafloor sediments, baseline CO2 measurements and knowledge of physical-chemical processes affecting the regional distribution of CO2 and pH are critical for the design of appropriate monitoring strategies to assess potential impacts of CO2 seepage from subseabed storage reservoirs. Surficial geological and geophysical information, such as that acquired from multibeam sonar and sub-bottom profiling, can be used to investigate the connectivity between the deep reservoirs and the surface, which is essential in establishing the reservoir containment properties. CO2 leakage can have a pronounced effect on sediments and rocks which in turn can have carryover effects to biogeochemical cycles. The effects of elevated CO2 on marine organisms are variable and species-specific but can also have cascading effects on communities and ecosystems, with marine benthic communities at some natural analogue sites (e.g. volcanic vents) showing decreased diversity, biomass, and trophic complexity. Despite their potential applications, environmental surveys and data are still not a standard and integral part of subseabed CO2 storage projects. However, the habitat mapping and seabed characterisation

  19. Sub-seabed CO2 Storage: Impact on Marine Ecosystems (ECO2) (Invited)

    NASA Astrophysics Data System (ADS)

    Wallmann, K. J.

    2013-12-01

    The European collaborative project ECO2 sets out to assess the environmental risks associated with storage of CO2 below the seabed (http://www.eco2-project.eu). It includes 28 partners from 7 European nations assessing the likelihood of leakage and impact of leakage on marine ecosystems. ECO2 studies the sedimentary cover and the overlying water column at active CO2 storage sites (Sleipner, Snøhvit) to look for any leakage pathways through the overburden and locate any seep sites at the seabed. High-resolution seismic data have been interpreted to feature a large number of vertical pipes and chimney structure cutting through parts of the sedimentary overburden at both storage sites. Formation waters are released through a 3 km long fracture 25 km north to the Sleipner platform while both natural gas and formation water are seeping through three abandoned wells located in the Sleipner area, as through many other old wells in the North Sea. The currently available data indicate that gases and fluids seeping at the seabed in the vicinity of the storage complex originate from the shallow overburden while CO2 stored at Sleipner and Snøhvit is fully retained in the storage formation. However, the observed geological features pose a number of important questions that are currently addressed by ECO2 via field work, data evaluation and numerical modelling: Are there any high permeability pathways for gas and fluid flow cutting through the overburden and linking the storage formation to the seep sites discovered at the seabed? Are seepage rates amplified by the ongoing storage operation at Sleipner? May CO2 stored at Sleipner and elsewhere ultimately leak through the overburden via seismic pipe and chimney structures, fractures and abandoned wells? CO2 release at the seabed was studied at three natural seep sites (Salt Dome Juist, Jan Mayen vent fields, Panarea) and via deliberate CO2 release experiments conducted in the vicinity of the Sleipner storage complex. The field

  20. CO2 Interaction with Geomaterials (Invited)

    NASA Astrophysics Data System (ADS)

    Romanov, V.; Howard, B. H.; Lynn, R. J.; Warzinski, R. P.; Hur, T.; Myshakin, E. M.; Lopano, C. L.; Voora, V. K.; Al-Saidi, W. A.; Jordan, K. D.; Cygan, R. T.; Guthrie, G. D.

    2010-12-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas #3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or “geopolymer”) theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  1. Selective CO2 Adsorption in a Supramolecular Organic Framework.

    PubMed

    Patil, Rahul S; Banerjee, Debasis; Zhang, Chen; Thallapally, Praveen K; Atwood, Jerry L

    2016-03-24

    Considering the rapidly rising CO2 level, there is a constant need for versatile materials which can selectively adsorb CO2 at low cost. The quest for efficient sorptive materials is still on since the practical applications of conventional porous materials possess certain limitations. In that context, we designed, synthesized, and characterized two novel supramolecular organic frameworks based on C-pentylpyrogallol[4]arene (PgC5 ) with spacer molecules, such as 4,4'-bipyridine (bpy). Highly optimized and symmetric intermolecular hydrogen-bonding interactions between the main building blocks and comparatively weak van der Waals interactions between solvent molecules and PgC5 leads to the formation of robust extended frameworks, which withstand solvent evacuation from the crystal lattice. The evacuated framework shows excellent affinity for carbon dioxide over nitrogen and adsorbs ca. 3 wt % of CO2 at ambient temperature and pressure.

  2. Capturing CO2 via reactions in nanopores.

    SciTech Connect

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.

    2008-10-01

    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team members expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  3. CO2 Capture with Enzyme Synthetic Analogue

    SciTech Connect

    Cordatos, Harry

    2010-03-01

    Project overview provides background on carbonic anhydrase transport mechanism for CO2 in the human body and proposed approach for ARPA-E project to create a synthetic enzyme analogue and utilize it in a membrane for CO2 capture from flue gas.

  4. CO2 Capture with Enzyme Synthetic Analogue

    SciTech Connect

    Cordatos, Harry

    2010-11-08

    Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.

  5. Improved Criteria for Increasing CO2 Storage Potential with CO2 Enhanced Oil Recovery

    NASA Astrophysics Data System (ADS)

    Bauman, J.; Pawar, R.

    2013-12-01

    In recent years it has been found that deployment of CO2 capture and storage technology at large scales will be difficult without significant incentives. One of the technologies that has been a focus in recent years is CO2 enhanced oil/gas recovery, where additional hydrocarbon recovery provides an economic incentive for deployment. The way CO2 EOR is currently deployed, maximization of additional oil production does not necessarily lead to maximization of stored CO2, though significant amounts of CO2 are stored regardless of the objective. To determine the potential of large-scale CO2 storage through CO2 EOR, it is necessary to determine the feasibility of deploying this technology over a wide range of oil/gas field characteristics. In addition it is also necessary to accurately estimate the ultimate CO2 storage potential and develop approaches that optimize oil recovery along with long-term CO2 storage. This study uses compositional reservoir simulations to further develop technical screening criteria that not only improve oil recovery, but maximize CO2 storage during enhanced oil recovery operations. Minimum miscibility pressure, maximum oil/ CO2 contact without the need of significant waterflooding, and CO2 breakthrough prevention are a few key parameters specific to the technical aspects of CO2 enhanced oil recovery that maximize CO2 storage. We have developed reduced order models based on simulation results to determine the ultimate oil recovery and CO2 storage potential in these formations. Our goal is to develop and demonstrate a methodology that can be used to determine feasibility and long-term CO2 storage potential of CO2 EOR technology.

  6. Geophysical monitoring technology for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  7. Zinc depolarized electrochemical CO2 concentration

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.

    1975-01-01

    Two zinc depolarized electrochemical carbon dioxide concentrator concepts were analytically and experimentally evaluated for portable life support system carbon dioxide (CO2) removal application. The first concept, referred to as the zinc hydrogen generator electrochemical depolarized CO2 concentrator, uses a ZHG to generate hydrogen for direct use in an EDC. The second concept, referred to as the zinc/electrochemical depolarized concentrator, uses a standard EDC cell construction modified for use with the Zn anode. The Zn anode is consumed and subsequently regenerated, thereby eliminating the need to supply H2 to the EDC for the CO2 removal process. The evaluation was based primarily on an analytical evaluation of the two ZnDCs at projected end item performance and hardware design levels. Both ZnDC concepts for PLSS CO2 removal application were found to be noncompetitive in both total equivalent launch weight and individual extravehicular activity mission volume when compared to other candidate regenerable PLSS CO2 scrubbers.

  8. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO2 Separation from CH4 and N2

    PubMed Central

    Otvagina, Ksenia V.; Mochalova, Alla E.; Sazanova, Tatyana S.; Petukhov, Anton N.; Moskvichev, Alexandr A.; Vorotyntsev, Andrey V.; Afonso, Carlos A. M.; Vorotyntsev, Ilya V.

    2016-01-01

    CO2 separation was found to be facilitated by transport membranes based on novel chitosan (CS)–poly(styrene) (PS) and chitosan (CS)–poly(acrylonitrile) (PAN) copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF4], [bmim][PF6], and [bmim][Tf2N] (IL). CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75–104 MPa for CS-PAN and 69–75 MPa for CS-PS). Ionic liquid (IL) doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO2 permeability 400 Barrers belongs to CS-b-PS/[bmim][BF4]. The highest selectivity α (CO2/N2) = 15.5 was achieved for CS-b-PAN/[bmim][BF4]. The operational temperature of the membranes is under 220 °C. PMID:27294964

  9. CO2 degassing in the Hartoušov mofette area, western Eger Rift, imaged by CO2 mapping and geoelectrical and gravity surveys

    NASA Astrophysics Data System (ADS)

    Nickschick, Tobias; Kämpf, Horst; Flechsig, Christina; Mrlina, Jan; Heinicke, Jens

    2015-11-01

    Strong, subcontinental mantle-dominated CO2 degassing occurs in the Hartoušov and Bublák mofette fields in the western Eger Rift. The combination of CO2 gas flux and soil gas measurements as well as gravity and geoelectric surveys provides insight into the surface and subsurface of this unique mofette area. CO2 soil gas and gas flux measurements reveal that large amounts of carbon dioxide are released via channels with diameters below 1 m. Carbon dioxide emissions of several tens and up to more than 100 kg day-1 are ejected via these small seeps. Measurements with small spacings are necessary to account for the point like, focused gas discharge in the lesser degassing surrounding. We estimate that between 23 and 97 tons of CO2 are released over an area of about 350,000 m2 each day in the Hartoušov mofette field. The application of widely used geostatistical tools leads to estimations of the CO2 discharge with very high standard deviations due to the strong positive skewness of the data distribution. Geophysical investigations via electrical resistivity tomography and gravity measurements were carried out over areas of strong seepage and reveal distinct anomalies in the subsurface below mofettes, indicating rock and sediment alterations and/or sediment transport by pressurised, ascending CO2 and water mobilised by it. This study reveals that the gas emanations only occur west of a morphological step which is related to a N-S-oriented fault zone, the Počatky-Plesná fault zone. The results of CO2 mapping and the geophysical studies can track the course of this fault zone in this area. Our results fit into a tectonic model in which the mofette fields are in the centres of two independent pull-apart basin-like structures. We hypothesise that the sinistral strike-slip movement of the Počatky-Plesná fault zone leads to a pull-apart basin-like opening, at which the strong, mantle-derived CO2 degassing occurs nowadays. Since the Hartoušov and Bublák mofette fields

  10. The ins and outs of CO2

    PubMed Central

    Raven, John A.; Beardall, John

    2016-01-01

    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3 –. The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3 – use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3 – active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3 – can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3 – pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3 –. Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. PMID:26466660

  11. Silvering substrates after CO2 snow cleaning

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2005-09-01

    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  12. Natural Gas Seepage Along the Edge of the Aquitaine Shelf (France): Origin and Flux Measurements

    NASA Astrophysics Data System (ADS)

    Ruffine, L.; Donval, J. P.; Battani, A.; Bignon, L.; Croguennec, C.; Caprais, J. C.; Birot, D.; Bayon, G.; Lantéri, N.; Levaché, D.; Dupré, S.

    2014-12-01

    A newly discovered and highly active seepage area has been acoustically mapped at the western edge of the Aquitaine Shelf in the Bay of Biscay [Dupré et al., 2014]. Three selected seeping sites have been investigated with a Remotely Operated Vehicle. All sites were characterized by vigorous gas emissions, and the occurrence of massive carbonate crusts and bacterial mats at the seafloor. Nine seeps have been sampled with the PEGAZ sampler. The latter allowed gas-bubble sampling and preservation at in situpressure, together with gas-flux measurement through its graduated transparent cone. The C2+ fraction of the gas samples accounts for less than 0.06 %-mol of the total composition. Both the abundance of methane and dD and d13C isotopic analyses of the hydrocarbons indicate a biogenic source generated by microbial reduction of carbon dioxide [Whiticar et al., 1986]. The analyses of the associated noble gases also provide further support for a shallow-depth generation. While sharing the same origin, the collected samples are different in other respects, such as the measured d13C values for carbon dioxide and the hydrocarbons. This is the case in particular for methane, with displays values in between -66.1 and -72.7 ‰. We hypothesized that such variations are the result of multiple gas-transport processes along with the occurrence of hydrocarbon oxidation at different rates within the sedimentary column. The measured gas fluxes are extremely heterogeneous from one seep to another, ranging from 18 to 193 m3.yr-1. These values will be discussed in detail by comparing them with values obtained from different measurement techniques at other gas-seeping sites. The GAZCOGNE study is co-funded by TOTAL and IFREMER as part of the PAMELA (Passive Margin Exploration Laboratories) scientific project. References:Dupré, S., L. Berger, N. Le Bouffant, C. Scalabrin, and J. F. Bourillet (2014), Fluid emissions at the Aquitaine Shelf (Bay of Biscay, France): a biogenic origin or

  13. TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N)

    Atmospheric Science Data Center

    2017-02-27

    ... TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) Project Title:  TES Discipline:  Tropospheric ... Earth Science Atmosphere Atmospheric Chemistry/Carbon and Hydrocarbon Compounds Order Data:  ...

  14. A usage of CO2 hydrate: convenient method to increase CO2 concentration in culturing algae.

    PubMed

    Nakano, Sho; Chang, Kwang-Hyeon; Shijima, Atsushi; Miyamoto, Hiroyuki; Sato, Yukio; Noto, Yuji; Ha, Jin-Yong; Sakamoto, Masaki

    2014-11-01

    The addition of CO2 to algal culture systems can increase algal biomass effectively. Generally, gas bubbling is used to increase CO2 levels in culture systems; however, it is difficult to quantitatively operate to control the concentration using this method. In this study, we tested the usability of CO2 hydrate for phytoplankton culture. Specifically, green algae Pseudokirchneriella subcapitata were cultured in COMBO medium that contained dissolved CO2 hydrate, after which its effects were evaluated. The experiment was conducted according to a general bioassay procedure (OECD TG201). CO2 promoted algae growth effectively (about 2-fold relative to the control), and the decrease in pH due to dissolution of the CO2 in water recovered soon because of photosynthesis. Since the CO2 hydrate method can control a CO2 concentration easily and quantitatively, it is expected to be useful in future applications.

  15. Synthesis, crystal structure, and magnetic characterization of the three-dimensional compound [Co2(cbut)(H2O)3]n (H4cbut = 1,2,3,4-cyclobutanetetracarboxylic acid).

    PubMed

    Díaz-Gallifa, Pau; Fabelo, Oscar; Pasán, Jorge; Cañadillas-Delgado, Laura; Rodríguez-Carvajal, Juan; Lloret, Francesc; Julve, Miguel; Ruiz-Pérez, Catalina

    2014-06-02

    A novel cobalt(II) complex of formula [Co2(cbut)(H2O)3]n (1) (H4cbut = 1,2,3,4-cyclobutanetetracarboxylic acid) has been synthesized under hydrothermal conditions and its crystal structure has been determined by means of synchrotron radiation and neutron powder diffraction. The crystal structure of 1 consists of layers of cobalt(II) ions extending in the bc-plane which are pillared along the crystallographic a-axis through the skeleton of the cbut(4-) ligand. Three crystallographically independent cobalt(II) ions [Co(1), Co(2), and Co(3)] occur in 1. They are all six-coordinate with four carboxylate-oxygens [Co(1)-Co(3)] and two cis-[Co(1)] or trans-water molecules [Co(2) and Co(3)] building distorted octahedral surroundings. Regular alternating double oxo(carboxylate) [between Co(1) and Co(1a)] and oxo(carboxylate) plus one aqua and a syn-syn carboxylate bridges [between Co(1) and Co(2)] occur along the crystallographic b-axis, the values of the cobalt-cobalt separation being 3.1259(8) and 3.1555(6) Å, respectively. These chains are connected to the Co(3) atoms through the OCO carboxylate along the [011] direction leading to the organic-inorganic bc-layers with Co(1)-OCO(anti-syn)-Co(3) and Co(2)-OCO(anti-anti)-Co(3) distances of 5.750(2) and 4.872(1) Å. The shortest interlayer cobalt-cobalt separation through the cbut(4-) skeleton along the crystallographic a-axis is 7.028(2) Å. Variable-temperature magnetic susceptibility measurements show the occurrence of antiferromagnetic ordering with a Néel temperature of 5.0 K, followed by a field-induced ferromagnetic transition under applied dc fields larger than 1500 Oe. The magnetic structure of 1 has been elucidated at low temperatures in zero field by neutron powder diffraction measurements and was found to be formed by ferromagnetic chains running along the b-axis which are antiferromagnetically coupled with the Co(3) ions through the c-axis giving rise to noncompensated magnetic moments within each bc

  16. CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites.

    PubMed

    Dai, Zhenxue; Viswanathan, Hari; Middleton, Richard; Pan, Feng; Ampomah, William; Yang, Changbing; Jia, Wei; Xiao, Ting; Lee, Si-Yong; McPherson, Brian; Balch, Robert; Grigg, Reid; White, Mark

    2016-07-19

    Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.

  17. CO2 deserts: implications of existing CO2 supply limitations for carbon management.

    PubMed

    Middleton, Richard S; Clarens, Andres F; Liu, Xiaowei; Bielicki, Jeffrey M; Levine, Jonathan S

    2014-10-07

    Efforts to mitigate the impacts of climate change will require deep reductions in anthropogenic CO2 emissions on the scale of gigatonnes per year. CO2 capture and utilization and/or storage technologies are a class of approaches that can substantially reduce CO2 emissions. Even though examples of this approach, such as CO2-enhanced oil recovery, are already being practiced on a scale >0.05 Gt/year, little attention has been focused on the supply of CO2 for these projects. Here, facility-scale data newly collected by the U.S. Environmental Protection Agency was processed to produce the first comprehensive map of CO2 sources from industrial sectors currently supplying CO2 in the United States. Collectively these sources produce 0.16 Gt/year, but the data reveal the presence of large areas without access to CO2 at an industrially relevant scale (>25 kt/year). Even though some facilities with the capability to capture CO2 are not doing so and in some regions pipeline networks are being built to link CO2 sources and sinks, much of the country exists in "CO2 deserts". A life cycle analysis of the sources reveals that the predominant source of CO2, dedicated wells, has the largest carbon footprint further confounding prospects for rational carbon management strategies.

  18. Effects of CO2 leakage on soil bacterial communities from simulated CO2-EOR areas.

    PubMed

    Chen, Fu; Yang, Yongjun; Ma, Yanjun; Hou, Huping; Zhang, Shaoliang; Ma, Jing

    2016-05-18

    CO2-EOR (enhanced oil recovery) has been proposed as a viable option for flooding oil and reducing anthropogenic CO2 contribution to the atmospheric pool. However, the potential risk of CO2 leakage from the process poses a threat to the ecological system. High-throughput sequencing was used to investigate the effects of CO2 emission on the composition and structure of soil bacterial communities. The diversity of bacterial communities notably decreased with increasing CO2 flux. The composition of bacterial communities varied along the CO2 flux, with increasing CO2 flux accompanied by increases in the relative abundance of Bacteroidetes and Firmicutes phyla, but decreases in the relative abundance of Acidobacteria and Chloroflexi phyla. Within the Firmicutes phylum, the genus Lactobacillus increased sharply when the CO2 flux was at its highest point. Alpha and beta diversity analysis revealed that differences in bacterial communities were best explained by CO2 flux. The redundancy analysis (RDA) revealed that differences in bacterial communities were best explained by soil pH values which related to CO2 flux. These results could be useful for evaluating the risk of potential CO2 leakages on the ecosystems associated with CO2-EOR processes.

  19. CO2 Driven Mineral Transformations in Fractured Reservoir

    NASA Astrophysics Data System (ADS)

    Schaef, T.

    2015-12-01

    Engineering fracture systems in low permeable formations to increase energy production, accelerate heat extraction, or to enhance injectivity for storing anthropogenic CO2, is a challenging endeavor. To complicate matters, caprocks, essential components of subsurface reservoirs, need to maintain their sealing integrity in this modified subsurface system. Supercritical CO2 (scCO2), a proposed non-aqueous based working fluid, is capable of driving mineral transformations in fracture environments. Water dissolution in scCO2 significantly impacts the reactivity of this fluid, largely due to the development of thin adsorbed H2O films on the surfaces of exposed rocks and minerals. Adsorbed H2O films are geochemically complex microenvironments that host mineral dissolution and precipitation processes that could be tailored to influence overall formation permeability. Furthermore, manipulating the composition of injected CO2 (e.g., moisture content and/or reactive gases such as O2, NOx, or SOx) could stimulate targeted mineral transformations that enhance or sustain reservoir performance. PNNL has developed specialized experimental techniques that can be used to characterize chemical reactions occurring between minerals and pressurized gases. For example, hydration of a natural shale sample (Woodford Shale) has been characterized by an in situ infrared spectroscopic technique as water partitions from the scCO2 onto the shale. Mineral dissolution and carbonate precipitation reactions were tracked by monitoring changes of Si-O and C-O stretching bands, respectively Structural changes indicated expandable clays in the shale such as montmorillonite are intercalated with scCO2, a process not observed with the non-expandable kaolinite component. Extreme scale ab initio molecular dynamics simulations were used in conjunction with model mineral systems to identify the driving force and mechanism of water films. They showed that the film nucleation and formation on minerals is

  20. PLAINS CO2 REDUCTION PARTNERSHIP

    SciTech Connect

    Thomas A. Erickson

    2004-04-01

    The PCOR Partnership continues to make great progress. Task 2 (Deployment Issues) activities have focused on utilizing Dakota Gasification Company (DGC) experience and data with respect to DGC participation in the enhanced oil recovery project at Weyburn, Saskatchewan. A solid line of communication has been developed with the Interstate Oil & Gas Compact Commission (IOGCC) for the mutual benefit of the PCOR Partnership and IOGCC's complementary efforts. Task 3 (Public Education and Outreach) activities have focused on developing a foundation of background materials in order to avoid a duplication of efforts and provide the best outreach and educational materials possible. Progress in Task 4 (Characterization and Evaluation) has included the development of a database format, the preliminary collection of data regarding CO{sub 2} sources and sinks, and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation. Task 5 (Modeling and Phase II Action Plans) activities have resulted in a conceptual model for screening and qualitatively assessing sequestration options. Task 5 activities have also been useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  1. PLAINS CO2 REDUCTION PARTNERSHIP

    SciTech Connect

    Thomas A. Erickson

    2004-01-01

    The PCOR Partnership is off to a very exciting and ambitious start. Task 1 activities have included the planning and execution of an internal kickoff meeting, participation in the DOE's national kickoff meeting, and the planning and execution of the first meeting of the PCOR Partnership at the Energy & Environmental Research Center (EERC). Task 2 activities have focused on developing effective and critical partnerships. A plan has been developed to utilize Dakota Gasification Company's (DGC) experience and data with respect to their participation in the enhanced oil recovery project at Weyburn, Saskatchewan. A solid line of communication has been developed with the Interstate Oil & Gas Compact Commission (IOGCC) for the mutual benefit of the PCOR Partnership and IOGCC's compensatory efforts. Task 3 activities have been focused on developing a foundation of background materials in order to avoid a duplication of efforts and provide the best outreach and educational materials possible. Progress in Task 4, Characterization and Evaluation, has included the development of a database format, the preliminary collection of data regarding CO{sub 2} sources and sinks, and data on the performance and costs for CO{sub 2} separation, capture, and treatment to prepare the fluid for pipeline transportation. Task 5 activities have resulted in a conceptual model for screening and qualitatively assessing sequestration options. Task 5 activities have also been useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  2. PLAINS CO2 REDUCTION PARTNERSHIP

    SciTech Connect

    Edward N. Steadman; John A. Harju; Erin M. O'Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Lisa S. Botnen

    2005-07-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership characterization work is nearing completion, and most remaining efforts are related to finalizing work products. Task 2 (Technology Deployment) has developed a Topical Report entitled ''Deployment Issues Related to Geologic CO{sub 2} Sequestration in the PCOR Partnership Region''. Task 3 (Public Outreach) has developed an informational Public Television program entitled ''Nature in the Balance'', about CO{sub 2} sequestration. The program was completed and aired on Prairie Public Television in this quarter. Task 4 (Sources, Sinks, and Infrastructure) efforts are nearing completion, and data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation are being incorporated into a series of topical reports. The expansion of the Decision Support System Geographic Information System database has continued with the development of a ''save bookmark'' feature that allows users to save a map from the system easily. A feature that allows users to develop a report that summarizes CO{sub 2} sequestration parameters was also developed. Task 5 (Modeling and Phase II Action Plans) focused on screening and qualitatively assessing sequestration options and developing economic estimates for important regional CO{sub 2} sequestration strategies.

  3. Engineered yeast for enhanced CO2 mineralization.

    PubMed

    Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d'Arminio; Riccò, Moreno; Bianchi, Daniele; Belcher, Angela

    2013-02-01

    In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented.

  4. Engineered yeast for enhanced CO2 mineralization†

    PubMed Central

    Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d’Arminio; Riccò, Moreno; Bianchi, Daniele; Belcher, Angela

    2014-01-01

    In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented. PMID:25289021

  5. Elevated CO2 and Soil Nitrogen Cycling

    NASA Astrophysics Data System (ADS)

    Hofmockel, K.; Schlesinger, W.

    2002-12-01

    Although forests can be large terrestrial carbon sinks, soil fertility can limit carbon sequestration in response to increased atmospheric CO2. During five years of CO2 fertilization (ambient + 200ppm) at the Duke Free-Air CO2 Enrichment (FACE) site, net primary production increased significantly by an average of 25% in treatment plots. Total nitrogen in the foliar canopy increased by 16%, requiring an additional 1.3 g N m-2yr-1 to be taken up from soils under elevated CO2. Mechanisms supporting increased nitrogen acquisition have not been identified. Here we report on biological N-fixation rates, using the acetylene reduction assay, in litter and mineral soil during three years of the CO2 enrichment experiment. Lack of a significant CO2 treatment effect on acetylene reduction indicates that carbon is not directly limiting biological N fixation. Nutrient addition experiments using a complete block design with glucose, Fe, Mo and P indicate biological N fixation is co-limited by molybdenum and carbon. These results suggest even if elevated atmospheric CO2 enhances below-ground carbon availability via root exudation, biological nitrogen fixation may not be stimulated due to micronutrient limitations. Assessment of future carbon sequestration by forest stands must consider limitations imposed by site fertility, including micronutrients.

  6. Glacial CO2 Cycles: A Composite Scenario

    NASA Astrophysics Data System (ADS)

    Broecker, W. S.

    2015-12-01

    There are three main contributors to the glacial drawdown of atmospheric CO2 content: starvation of the supply of carbon to the ocean-atmosphere reservoir, excess CO2 storage in the deep sea, and surface-ocean cooling. In this talk, I explore a scenario in which all three play significant roles. Key to this scenario is the assumption that deep ocean storage is related to the extent of nutrient stratification of the deep Atlantic. The stronger this stratification, the larger the storage of respiration CO2. Further, it is my contention that the link between Milankovitch insolation cycles and climate is reorganizations of the ocean's thermohaline circulation leading to changes in the deep ocean's CO2 storage. If this is the case, the deep Atlantic d13C record kept in benthic foraminifera shells tells us that deep ocean CO2 storage follows Northern Hemisphere summer insolation cycles and thus lacks the downward ramp so prominent in the records of sea level, benthic 18O and CO2. Rather, the ramp is created by the damping of planetary CO2 emissions during glacial time intervals. As it is premature to present a specific scenario, I provide an example as to how these three contributors might be combined. As their magnitudes and shapes remain largely unconstrained, the intent of this exercise is to provoke creative thinking.

  7. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira,

    2004-01-01

    We evaluate accelerated weathering of limestone (AWL: CO2 + CaCO3 + H2O=> Ca2+ + 2HCO3-) as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology. With access to seawater and limestone being essential to this approach, significant limestone resources are close to most CO2-emitting power plants along the coastal US. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could be used as an inexpensive source of AWL carbonate. Under such circumstances CO2 mitigation cost could be as low as $3-$4/tonne. More broadly, 10-20% of US point-source CO2 emissions could be treated at $20-$30/tonne CO2. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  8. Experimental multi-phase H2O-CO2 brine interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.; Koksalan, T.

    2004-01-01

    The burning of fossil fuel and other anthropogenic activities have caused a continuous and dramatic 30% increase of atmospheric CO2 over the past 150 yr. CO2 sequestration is increasingly being viewed as a tool for managing these anthropogenic CO2 emissions to the atmosphere. CO2-saturated brine-rock experiments were carried out to evaluate the effects of multiphase H2O-CO2 fluids on mineral equilibria and the potential for CO2 sequestration in mineral phases within deep-saline aquifers. Experimental results were generally consistent with theoretical thermodynamic calculations. The solubility of CO2 was enhanced in brines in the presence of both limestone and sandstone relative to brines alone. Reactions between CO2 saturated brines and arkosic sandstones were characterized by desiccation of the brine and changes in the chemical composition of the brine suggesting fixation of CO2 in mineral phases. These reactions were occurring on a measurable but kinetically slow time scale at 120??C.

  9. Geological factors affecting CO2 plume distribution

    USGS Publications Warehouse

    Frailey, S.M.; Leetaru, H.

    2009-01-01

    Understanding the lateral extent of a CO2 plume has important implications with regards to buying/leasing pore volume rights, defining the area of review for an injection permit, determining the extent of an MMV plan, and managing basin-scale sequestration from multiple injection sites. The vertical and lateral distribution of CO2 has implications with regards to estimating CO2 storage volume at a specific site and the pore pressure below the caprock. Geologic and flow characteristics such as effective permeability and porosity, capillary pressure, lateral and vertical permeability anisotropy, geologic structure, and thickness all influence and affect the plume distribution to varying degrees. Depending on the variations in these parameters one may dominate the shape and size of the plume. Additionally, these parameters do not necessarily act independently. A comparison of viscous and gravity forces will determine the degree of vertical and lateral flow. However, this is dependent on formation thickness. For example in a thick zone with injection near the base, the CO2 moves radially from the well but will slow at greater radii and vertical movement will dominate. Generally the CO2 plume will not appreciably move laterally until the caprock or a relatively low permeability interval is contacted by the CO2. Conversely, in a relatively thin zone with the injection interval over nearly the entire zone, near the wellbore the CO2 will be distributed over the entire vertical component and will move laterally much further with minimal vertical movement. Assuming no geologic structure, injecting into a thin zone or into a thick zone immediately under a caprock will result in a larger plume size. With a geologic structure such as an anticline, CO2 plume size may be restricted and injection immediately below the caprock may have less lateral plume growth because the structure will induce downward vertical movement of the CO2 until the outer edge of the plume reaches a spill

  10. Regenerable Sorbent for CO2 Removal

    NASA Technical Reports Server (NTRS)

    Alptekin, Gokhan; Jayaraman, Ambal

    2013-01-01

    A durable, high-capacity regenerable sorbent can remove CO2 from the breathing loop under a Martian atmosphere. The system design allows near-ambient temperature operation, needs only a small temperature swing, and sorbent regeneration takes place at or above 8 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the breathing loop. The physical adsorbent can be used in a metabolic, heat-driven TSA system to remove CO2 from the breathing loop of the astronaut and reject it to the Martian atmosphere. Two (or more) alternating sorbent beds continuously scrub and reject CO2 from the spacesuit ventilation loop. The sorbent beds are cycled, alternately absorbing CO2 from the vent loop and rejecting the adsorbed material into the environment at a high CO2 partial pressure (above 8 torr). The system does not need to run the adsorber at cryogenic temperatures, and uses a much smaller temperature swing. The sorbent removes CO2 via a weak chemical interaction. The interaction is strong enough to enable CO2 adsorption even at 3 to 7.6 torr. However, because the interaction between the surface adsorption sites and the CO2 is relatively weak, the heat input needed to regenerate the sorbent is much lower than that for chemical absorbents. The sorbent developed in this project could potentially find use in a large commercial market in the removal of CO2 emissions from coal-fired power plants, if regulations are put in place to curb carbon emissions from power plants.

  11. Estimating lake-atmosphere CO2 exchange

    USGS Publications Warehouse

    Anderson, D.E.; Striegl, R.G.; Stannard, D.I.; Michmerhuizen, C.M.; McConnaughey, T.A.; LaBaugh, J.W.

    1999-01-01

    Lake-atmosphere CO2 flux was directly measured above a small, woodland lake using the eddy covariance technique and compared with fluxes deduced from changes in measured lake-water CO2 storage and with flux predictions from boundary-layer and surface-renewal models. Over a 3-yr period, lake-atmosphere exchanges of CO2 were measured over 5 weeks in spring, summer, and fall. Observed springtime CO2 efflux was large (2.3-2.7 ??mol m-2 s-1) immediately after lake-thaw. That efflux decreased exponentially with time to less than 0.2 ??mol m-2 s-1 within 2 weeks. Substantial interannual variability was found in the magnitudes of springtime efflux, surface water CO2 concentrations, lake CO2 storage, and meteorological conditions. Summertime measurements show a weak diurnal trend with a small average downward flux (-0.17 ??mol m-2 s-1) to the lake's surface, while late fall flux was trendless and smaller (-0.0021 ??mol m-2 s-1). Large springtime efflux afforded an opportunity to make direct measurement of lake-atmosphere fluxes well above the detection limits of eddy covariance instruments, facilitating the testing of different gas flux methodologies and air-water gas-transfer models. Although there was an overall agreement in fluxes determined by eddy covariance and those calculated from lake-water storage change in CO2, agreement was inconsistent between eddy covariance flux measurements and fluxes predicted by boundary-layer and surface-renewal models. Comparison of measured and modeled transfer velocities for CO2, along with measured and modeled cumulative CO2 flux, indicates that in most instances the surface-renewal model underpredicts actual flux. Greater underestimates were found with comparisons involving homogeneous boundary-layer models. No physical mechanism responsible for the inconsistencies was identified by analyzing coincidentally measured environmental variables.

  12. Atmospheric CO2 Removal by Enhancing Weathering

    NASA Astrophysics Data System (ADS)

    Koster van Groos, A. F.; Schuiling, R. D.

    2014-12-01

    The increase of the CO2 content in the atmosphere by the release of anthropogenic CO2 may be addressed by the enhancement of weathering at the surface of the earth. The average emission of mantle-derived CO2 through volcanism is ~0.3 Gt/year (109 ton/year). Considering the ~3.000 Gt of CO2 present in the atmosphere, the residence time of CO2 in the earth's atmosphere is ~10,000 years. Because the vast proportion of carbon in biomass is recycled through the atmosphere, CO2 is continuously removed by a series of weathering reactions of silicate minerals and stored in calcium and magnesium carbonates. The addition of anthropogenic CO2 from fossil fuel and cement production, which currently exceeds 35 Gt/year and dwarfs the natural production 100-fold, cannot be compensated by current rates of weathering, and atmospheric CO2 levels are rising rapidly. To address this increase in CO2 levels, weathering rates would have to be accelerated on a commensurate scale. Olivine ((Mg,Fe)2SiO4) is the most reactive silicate mineral in the weathering process. This mineral is the major constituent in relatively common ultramafic rocks such as dunites (olivine content > 90%). To consume the current total annual anthropogenic release of CO2, using a simplified weathering reaction (Mg2SiO4 + 4CO2 + 4H2O --> 2 Mg2+ + 4HCO3- + H4SiO4) would require ~30 Gt/year or ~8-9 km3/year of dunite. This is a large volume; it is about double the total amount of ore and gravel currently mined (~ 17 Gt/year). To mine and crush these rocks to <100 μm costs ~ 8/ton. The transport and distribution over the earth's surface involves additional costs, that may reach 2-5/ton. Thus, the cost of remediation for the release of anthropogenic CO2 is 300-400 billion/year. This compares to a 2014 global GDP of ~80 trillion. Because weathering reactions require the presence of water and proceed more rapidly at higher temperatures, the preferred environments to enhance weathering are the wet tropics. From a socio

  13. The oceanic sink for anthropogenic CO2.

    PubMed

    Sabine, Christopher L; Feely, Richard A; Gruber, Nicolas; Key, Robert M; Lee, Kitack; Bullister, John L; Wanninkhof, Rik; Wong, C S; Wallace, Douglas W R; Tilbrook, Bronte; Millero, Frank J; Peng, Tsung-Hung; Kozyr, Alexander; Ono, Tsueno; Rios, Aida F

    2004-07-16

    Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for approximately 48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.

  14. Natural Analog for Geologic Storage of CO2: CO2 accumulation in China

    NASA Astrophysics Data System (ADS)

    Liu, L.; Xu, T.; Liu, N.; Zhou, B.

    2012-12-01

    Natural accumulations of CO2 are potential analogues of CO2 geological storage that can provide useful information on the behaviour of supercritical CO2 in reservoirs. Natural CO2 accumulations are common across Northeast China, and, although they occur in a wide variety of geological settings, their distribution is principally controlled by the Mesozoic-Cenozoic rift basins and associated Quaternary volcanism. High CO2 concentrations (>60 CO2%) in natural gas reservoirs are usually related to volcanism and magmatism, and possesses mantle-genetic origin. CO2 reservoirs consist of sandstone, volcanic rocks and carbonate rocks with the buried depth from 2000-3000 m. Dawsonite is recognized in almost all of the CO2-bearing basin, which has been proved to share the same carbon source with CO2 in the reservoirs in Songliao basin, Hailaer basin and Donghai basin. Petrographic data show that dawsonite is abundant in feldspar- rich sandstone, volcanic rock fragment-rich sandstones and tuff. In some cases, high percentage of dawsonite cement constitutes a diagenetic seal, which occurs in the reservoir-mudstone caprock and prevents upward leakage of CO2. Besides dawsonite, mantle-genetic CO2 flux leads to the formation of calcite, ankerite and siderite. The statistics of porosity and permeability measured from the dawsonite-bearing sandstone and dawsonite-absent sandstone with the almost same burial depth in Songliao basin show that the mantle-genetic CO2 flux result in lower reservoir quality, suggesting that mineral trapping for CO2 is significant. Chemical analyses of formation water in Songliao basin and Hailaer basin indicate that the concentrations of TDS, HCO3-,CO32-, Mg2+,Ca2+ and Na+ + K+ in dawsonite-bearing sandstone are higher than that in dawsonite-absent sandstone. Distribution of CO2 and dawsonite is constrainted by the regional caprocks in the Songliao basin. The charging time of the mantle-genetic CO2 in China dates from 50 to 25 Ma.

  15. 40 CFR 98.423 - Calculating CO2 supply.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... = Quarterly CO2 concentration measurement in flow for flow meter u in quarter p (wt. %CO2). Qp,u = Quarterly... (metric tons) through flow meter u. CCO2,p = Quarterly CO2 concentration measurement in flow for flow... delivered by CO2 stream u. CCO2,p,u = Quarterly CO2 concentration measurement of CO2 stream u that...

  16. 40 CFR 98.423 - Calculating CO2 supply.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... = Quarterly CO2 concentration measurement in flow for flow meter u in quarter p (wt. %CO2). Qp,u = Quarterly... (metric tons) through flow meter u. CCO2,p = Quarterly CO2 concentration measurement in flow for flow... delivered by CO2 stream u. CCO2,p,u = Quarterly CO2 concentration measurement of CO2 stream u that...

  17. 132. Credit JTL. Smaller feeder pipes collecting seepage and water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    132. Credit JTL. Smaller feeder pipes collecting seepage and water from springs for the Eagle Canyon flume. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  18. Atmospheric CO2 concentrations during ancient greenhouse climates were similar to those predicted for A.D. 2100.

    PubMed

    Breecker, D O; Sharp, Z D; McFadden, L D

    2010-01-12

    Quantifying atmospheric CO(2) concentrations ([CO(2)](atm)) during Earth's ancient greenhouse episodes is essential for accurately predicting the response of future climate to elevated CO(2) levels. Empirical estimates of [CO(2)](atm) during Paleozoic and Mesozoic greenhouse climates are based primarily on the carbon isotope composition of calcium carbonate in fossil soils. We report that greenhouse [CO(2)](atm) have been significantly overestimated because previously assumed soil CO(2) concentrations during carbonate formation are too high. More accurate [CO(2)](atm), resulting from better constraints on soil CO(2), indicate that large (1,000s of ppmV) fluctuations in [CO(2)](atm) did not characterize ancient climates and that past greenhouse climates were accompanied by concentrations similar to those projected for A.D. 2100.

  19. Enhanced algal CO(2) sequestration through calcite deposition by Chlorella sp. and Spirulina platensis in a mini-raceway pond.

    PubMed

    Ramanan, Rishiram; Kannan, Krishnamurthi; Deshkar, Ashok; Yadav, Raju; Chakrabarti, Tapan

    2010-04-01

    Biological CO(2) sequestration using algal reactors is one of the most promising and environmentally benign technologies to sequester CO(2). This research study was taken up to alleviate certain limitations associated with the technology such as low CO(2) sequestration efficiency and low biomass yields. The study demonstrates an increase in CO(2) sequestration efficiency by maneuvering chemically aided biological sequestration of CO(2). Chlorella sp. and Spirulina platensis showed 46% and 39% mean fixation efficiency, respectively, at input CO(2) concentration of 10%. The effect of acetazolamide, a potent carbonic anhydrase inhibitor, on CO(2) sequestration efficiency was studied to demonstrate the role of carbonic anhydrase in calcite deposition. Calcite formed by both species was characterized by scanning electron microscopy coupled electron dispersive spectroscopy and X-ray diffraction. The overall scheme of calcite deposition coupled CO(2) fixation with commercially utilizable biomass as a product seems a viable option in the efforts to sequester increasing CO(2) emissions.

  20. CO2-Leaking Well - Analytical Modeling

    NASA Astrophysics Data System (ADS)

    Wertz, F.; Audigane, P.; Bouc, O.

    2009-04-01

    The long-term integrity of CO2 storage in geological system relies highly on local trapping mechanisms but also on the absence/control of any kind of outlets. Indeed numerous pathways (faults, wells, rock heterogeneities…) exist that can lead stored gas back to the surface. Thus, such leakage risks must be assessed and quantified if possible. In France, BRGM is inquired for evaluating safety criteria and developing a methodology for qualifying potential geological storage sites. This implies in particular to study the leakage scenario, here through a water-filled well as a worth scenario case. In order to determine the kinds of impacts leaking CO2 can have; knowing the velocity and flow rate of uprising CO2 is a necessity. That is why a better knowledge of CO2 in storage conditions and its behaviour with the environment is required. The following study aims at characterising the CO2 flowing into the well and then rising up in a water column over the vertical dimension. An analytical model was built that describes: - In a first step, the CO2 flow between the reservoir and the inside of the well, depending on quality and thickness of different seals, which determines the flow rate through the well. - In a second step, the CO2 uprising through an open and water filled well, however in steady state, which excludes a priori the characterisation of periodic or chaotic behaviours such as geyser formation. The objective is to give numerous orders of magnitude concerning CO2 thermodynamic properties while rising up: specific enthalpy, density, viscosity, velocity, flow, gas volume fraction and expansion, pressure and temperature gradient. Dissolution is partially taken into account, however without kinetic. The strength of this model is to compute analytically - easily and instantaneously - the 1-dimensional rising velocity of CO2 in a water column as a function of the CO2 density, interfacial tension and initial volume fraction. Characteristic speeds - the ones given by

  1. Catalytic gasification of biomass (Miscanthus) enhanced by CO2 sorption.

    PubMed

    Zamboni, I; Debal, M; Matt, M; Girods, P; Kiennemann, A; Rogaume, Y; Courson, C

    2016-11-01

    The main objective of this work concerns the coupling of biomass gasification reaction and CO2 sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO2 sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca12Al14O33/olivine bi-functional materials to reduce heavy tar production. Experiments have been carried out in a fluidized bed gasifier using steam as the fluidizing medium to improve hydrogen production. Bed materials consisting of CaO-based oxide for CO2 sorption (CaO-Ca12Al14O33) deposited on olivine for tar reduction were synthesized, their structural and textural properties were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and temperature-programmed reduction (TPR) methods, and the determination of their sorption capacity and stability analyzed by thermogravimetric analysis (TGA). It appears that this CaO-Ca12Al14O33/olivine sorbent/catalyst presents a good CO2 sorption stability (for seven cycles of carbonation/decarbonation). Compared to olivine and Fe/olivine in a fixed bed reactor for steam reforming of toluene chosen as tar model compound, it shows a better hydrogen production rate and a lower CO2 selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca12Al14O33/olivine as bed material at 700 °C leads to a higher H2 production than olivine at 800 °C thanks to CO2 sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 °C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.

  2. Experimental multi-phase CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.J.; Koksalan, T.

    2004-01-01

    Long-term CO2 saturated brine-rock experiments were conducted to evaluate the effects of multiphase H2O-CO2 fluids on mineral equilibria and the potential for CO2 sequestration mineral phases within deep-saline aquifers. Experimental results were consistent with theoretical thermodynamic calculations when CO2-saturated brines were reacted with limestone rocks. The CO2-saturated brine-limestone reactions were characterized by compositional and mineralogical-changes in the aquifer fluid and formation rocks that were dependent on initial brine composition as were the changes in formation porosity, especially dissolved sulfate. The solubility of CO2 was enhanced in brines in the presence of both limestone and sandstone rocks relative to brines alone. Reactions between CO2 saturated brines and arkosic sandstones were characterized by desiccation of the brine and changes in the chemical composition of the brine suggesting fixation of CO2 in mineral phases. These reactions occured on a measurable but kinetically slow time scale at 120??C.

  3. H-Area Seepage Basins groundwater monitoring report

    SciTech Connect

    Not Available

    1992-09-01

    During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin.

  4. Robust hydrogen-bonded self-assemblies from biimidazole complexes. Synthesis and structural characterization of [M(biimidazole)2(OH2)2]2+ (M = Co2+, Ni2+) complexes and carboxylate modules.

    PubMed

    Atencio, Reinaldo; Chacón, Mirbel; González, Teresa; Briceño, Alexander; Agrifoglio, Giuseppe; Sierraalta, Anibal

    2004-02-21

    A robust heteromeric hydrogen-bonded synthon [R2(2) (9)-Id] is exploited to drive the modular self-assembly of four coordination complexes [M(H2biim)2(OH2)2]2+ (M = Co2+, Ni2+) and carboxylate counterions. This strategy allowed us to build molecular architectures of 0-, 1-, and 2-dimensions. A hydrogen-bonded 2D-network with cavities has been designed, which maintains its striking integrity after reversible water desorption-resorption processes.

  5. CO2 Sensing and CO2 Regulation of Stomatal Conductance: Advances and Open Questions.

    PubMed

    Engineer, Cawas B; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordström, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian I

    2016-01-01

    Guard cells form epidermal stomatal gas-exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration ([CO2]) in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense [CO2] changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in the CO2 regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars that perform better in a shifting climate.

  6. Modeling Coupled Evaporation and Seepage in Ventilated Cavities

    SciTech Connect

    T. Ghezzehei; R. Trautz; S. Finsterle; P. Cook; C. Ahlers

    2004-07-01

    Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small.

  7. Translucent CO2 ice on Mars ?

    NASA Astrophysics Data System (ADS)

    Schmidt, Frederic; Andrieu, Francois; Douté, Sylvain; Schmitt, Bernard

    2016-10-01

    The Martian climate is driven by the condensation/sublimation of CO2 representing 95% of the atmosphere. Many active surface features (such dark spot, dark flows), have been potentially linked to CO2 exchange. Understanding the surface/atmosphere interactions is a major issue, for both atmospheric but also surface science. This study aims at estimating the physical properties of the seasonal CO2 ice deposits. Are these deposits granular or compact? What is the thickness of the ice? How much impurities are included within the ice? These questions have been highly debated in the literature, in particular the presence of a translucent slab ice, the link with the H2O cycle. In particular the cold jet geyser model requires translucent CO2 ice. We use radiative transfer models to simulate spectroscopic data from the CRISM instrument and perform an inversion to estimate model's parameters though time. We then discuss the consistency of the results with other datasets.

  8. Spatiotemporal variability of lake pCO2 and CO2 fluxes in a hemiboreal catchment

    NASA Astrophysics Data System (ADS)

    Natchimuthu, Sivakiruthika; Sundgren, Ingrid; Gâlfalk, Magnus; Klemedtsson, Leif; Bastviken, David

    2017-01-01

    Globally, lakes are frequently supersaturated with carbon dioxide (CO2) and are major emitters of carbon to the atmosphere. Recent studies have generated awareness of the high variability in pCO2aq (the partial pressure corresponding to the concentration in water) and CO2 fluxes to the atmosphere and the need for better accounting for this variability. However, studies simultaneously accounting for both spatial and temporal variability of pCO2aq and CO2 fluxes in lakes are rare. We measured pCO2aq (by both manual sampling and mini loggers) and CO2 fluxes, covering spatial variability in open water areas of three lakes of different character in a Swedish catchment for 2 years. Spatial pCO2aq variability within lakes was linked to distance from shore, proximity to stream inlets, and deepwater upwelling events. Temporally, pCO2aq variability was linked with variability in dissolved organic carbon, total nitrogen, and dissolved oxygen. While previous studies over short time periods (1 to 6 h) observed gas transfer velocity (k) to be more variable than pCO2aq, our work shows that over longer time (days to weeks) pCO2aq variability was greater and affected CO2 fluxes much more than k. We demonstrate that ≥8 measurement days distributed over multiple seasons in combination with sufficient spatial coverage (≥8 locations during stratification periods and 5 or less in spring and autumn) are a key for representative yearly whole lake flux estimates. This study illustrates the importance of considering spatiotemporal variability in pCO2aq and CO2 fluxes to generate representative whole lake estimates.

  9. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    NASA Astrophysics Data System (ADS)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  10. Study on CO2 global recycling system.

    PubMed

    Takeuchi, M; Sakamoto, Y; Niwa, S

    2001-09-28

    In order to assist in finding ways to mitigate CO2 emission and to slow the depletion of fossil fuels we have established and evaluated a representative system, which consists of three technologies developed in our laboratory. These technologies were in CO2 recovery, hydrogen production and methanol synthesis and in addition we established the necessary supporting systems. Analysis of outline designs of the large scale renewable energy power generation system and this system and energy input for building plant, energy input for running plant has been conducted based on a case using this system for a 1000-MW coal fired power plant, followed by an evaluation of the material balance and energy balance. The results are as follows. Energy efficiency is 34%, the CO2 reduction rate is 41%, the balance ratio of the energy and CO2 of the system is 2.2 and 1.8, respectively, on the assumption that the primary renewable energy is solar thermal power generation, the stationary CO2 emission source is a coal-fired power plant and the generation efficiency of the methanol power plant is 60%. By adopting the system, 3.7 million tons of CO2 can be recovered, approximately 2.7 million tons of methanol can be produced, and 15.4 billion kWh of electricity can be generated per year. Compared to generating all electrical power using only coal, approximately 2.6 million tons of coal per year can be saved and approximately 2.15 million tons of CO2 emission can be reduced. Therefore, it is clearly revealed that this system would be effective to reduce CO2 emissions and to utilize renewable energy.

  11. Bifunctional Catalysts for CO2 Reduction

    DTIC Science & Technology

    2014-09-30

    AFRL-OSR-VA-TR-2014-0243 Bifunctional catalysts for CO2 reduction Theodore Betley HARVARD COLLEGE PRESIDENT & FELLOWS OF Final Report 09/30/2014...Prescribed by ANSI Std. Z39.18 PI: Theodore A. Betley Project: Bifunctional Catalysts for CO2 Reduction Project #: 130214 A. Specific Aims 1... catalyst platforms. Details for the construction of these materials, as they deviate from the salen/salan platforms will be described below. 2. Probe

  12. The Twelve Principles of CO2 CHEMISTRY.

    PubMed

    Poliakoff, Martyn; Leitner, Walter; Streng, Emilia S

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  13. CO2 Acquisition Membrane (CAM) Project

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    2003-01-01

    The CO2 Acquisition Membrane (CAM) project was performed to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes developed in this project are targeted toward In Situ Resource Utilization (ISRU) applications, such as In Situ Propellant Production (ISPP) and In Situ Consumables Production (ISCP). These membrane materials may be used in a variety of ISRU systems, for example as the atmospheric inlet filter for an ISPP process to enhance the concentration of CO2 for use as a reactant gas, to passively separate argon and nitrogen trace gases from CO2 for habitat pressurization, to provide a system for removal of CO2 from breathing gases in a closed environment, or within a process stream to selectively separate CO2 from other gaseous components. The membranes identified and developed for CAM were evaluated for use in candidate ISRU processes and other gas separation applications, and will help to lay the foundation for future unmanned sample return and human space missions. CAM is a cooperative project split among three institutions: Lockheed Martin Astronautics (LMA), the Colorado School of Mines (CSM), and Marshall Space Flight Center (MSFC).

  14. CO2 cooling in terrestrial planet thermospheres

    NASA Technical Reports Server (NTRS)

    Bougher, S. W.; Hunten, D. M.; Roble, R. G.

    1994-01-01

    We examine the recent progress in the debate on the CO2-O relaxation rate, its temperature dependence, and its corresponding impact on the thermospheric heat budgets of Venus, Earth, and Mars. This comparative approach provides the broadest range of conditions under which a common CO2-O relaxation rate should provide consistent results. New global mean calculations are presented for the heat budgets of these three planets using large CO2-O relaxation rates that have been inferred recently from Earth CO2 radiance measurements and laboratory studies. Results indicate that available Venus and Mars data constrain the CO2-O relaxation rate to be 2-4 x 10(exp -12)/cu cm/s at 300 K. For Venus, this strong cooling serves as an effective thermostat that gives rise to a small variation of thermospheric temperatures over the solar cycle, just as observed. Conversely, CO2 cooling does not appear to be dominant in the dayside heat budget of the Mars thermosphere over most of the solar cycle. For the Earth, this strong cooling implies that the lower thermosphere does not typically require significant eddy diffusion or heat conduction. However, global-scale dynamics or an additional heating mechanism may be needed to restore calculated temperatures to observed values when relaxation rates exceeding 2 x 10(exp -12)/cu cm/s are employed.

  15. CO2 Efflux from Cleared Mangrove Peat

    PubMed Central

    Lovelock, Catherine E.; Ruess, Roger W.; Feller, Ilka C.

    2011-01-01

    Background CO2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. Methodology/Principal Findings We measured CO2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO2 efflux. CO2 efflux from soils declines from time of clearing from ∼10 600 tonnes km−2 year−1 in the first year to 3000 tonnes km2 year−1 after 20 years since clearing. Disturbing peat leads to short term increases in CO2 efflux (27 umol m−2 s−1), but this had returned to baseline levels within 2 days. Conclusions/Significance Deforesting mangroves that grow on peat soils results in CO2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks. PMID:21738628

  16. Density of aqueous solutions of CO2

    SciTech Connect

    Garcia, Julio E.

    2001-10-10

    In this report, we present a numerical representation for the partial molar volume of CO2 in water and the calculation of the corresponding aqueous solution density. The motivation behind this work is related to the importance of having accurate representations for aqueous phase properties in the numerical simulation of carbon dioxide disposal into aquifers as well as in geothermal applications. According to reported experimental data the density of aqueous solutions of CO2 can be as much as 2-3% higher than pure water density. This density variation might produce an influence on the groundwater flow regime. For instance, in geologic sequestration of CO2, convective transport mixing might occur when, several years after injection of carbon dioxide has stopped, the CO2-rich gas phase is concentrated at the top of the formation, just below an overlaying caprock. In this particular case the heavier CO2 saturated water will flow downward and will be replaced by water with a lesser CO2 content.

  17. An experimental study of diopside- CO2 -brine interaction

    NASA Astrophysics Data System (ADS)

    Zhou, Bing; Liu, Li; Ming, Xiaoran; Guo, Yanjun

    2014-05-01

    Diopside is one of the main minerals that consist igneous rock. It is characterized by high content of divalent cations like Ca, Mg, and Fe and relatively fast dissolution rate. These features make it an expected mineral of releasing metal ions for mineral carbonation during the research of mineral trapping of CO2. This study focus on the dissolution amount and micro-scale observing of diopside after the reaction with CO2 and brine under 100, 150, and 200°C. Each of the three experiments are carried out with 2 pieces of diopside (10mm*10mm*4mm) and 500ml Nacl (1mol/L) for 72h, and the pressure inside is 7Mp after injecting of CO2. SEM analysis of the surface of diopside before and after the experiments shows that the degree of corrosion increase with the rising of temperature. The slices of diopside lose 0.8% of its weight at the end of the experiments of 100°C, about 1.8% at 150°C, and about 3.92% at 200°C. Silicon concentrations after reaction are 14.55 mg/L (100°C), 47.02 mg/L (150°C), and 65.32 mg/L (200°C), which also prove the elevated temperature has a positive influence on dissolution of solid. Concentration of calcium and bicarbonate increase with temperature, while magnesium and iron are not. This may due to the heterogeneity of the composition in each piece of solid, or the precipitation of some compounds during the experiments. There are some amorphous compounds are found under SEM, which are mostly consisted of C, O, Na, Mg, Si, and Ca. A simple numerical simulation of CO2-diopside-brine interaction is carried out by TOUGHREACT. The setting of parameters are based on the experiments. Diopside reacts with 1mol/L Nacl under the CO2 partial pressure of 10Mp and the temperature keeps 100°C. The results present that the volume percent of precipitated carbonates (calcite and magnesite) reaches 1.23% after 100 years, which means 1m3 diopside could capture 16.76kg CO2 after 100 years by the means of mineral carbonation. This study reveals the

  18. Carbonic anhydrase mimics for enhanced CO2 absorption in an amine-based capture solvent.

    PubMed

    Kelsey, Rachael A; Miller, David A; Parkin, Sean R; Liu, Kun; Remias, Joe E; Yang, Yue; Lightstone, Felice C; Liu, Kunlei; Lippert, Cameron A; Odom, Susan A

    2016-01-07

    Two new small-molecule enzyme mimics of carbonic anhydrase were prepared and characterized. These complexes contain the salen-like ligand bis(hydroxyphenyl)phenanthroline. This ligand is similar to the salen-type ligands previously incorporated into carbonic anhydrase mimics but contains no hydrolyzable imine groups and therefore serves as a promising ligand scaffold for the synthesis of a more robust CO2 hydration catalyst. These homogeneous catalysts were investigated for CO2 hydration in concentrated primary amine solutions through which a dilute CO2 (14%) fluid stream was flowed and showed exceptional activity for increased CO2 absorption rates.

  19. Long-term pCO2 trends in Adirondack Lakes

    NASA Astrophysics Data System (ADS)

    Seekell, David A.; Gudasz, Cristian

    2016-05-01

    Lakes are globally significant sources of CO2 to the atmosphere. However, there are few temporally resolved records of lake CO2 concentrations and long-term patterns are poorly characterized. We evaluated annual trends in the partial pressure of CO2 (pCO2) based on chemical measurements from 31 Adirondack Lakes taken monthly over an 18 year period. All lakes were supersaturated with CO2 and were sources of CO2 to the atmosphere. There were significant pCO2 trends in 29% of lakes. The median magnitude of significant positive trends was 32.1 µatm yr-1. Overall, 52% of lakes had pCO2 trends greater than those reported for the atmosphere and ocean. Significant trends in lake pCO2 were attributable to regional recovery from acid deposition and changing patterns of ice cover. These results illustrate that lake pCO2 can respond rapidly to environmental change, but the lack of significant trend in 71% of lakes indicates substantial lake-to-lake variation in magnitude of response.

  20. Surface modification of a low cost bentonite for post-combustion CO2 capture

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Park, Dong-Wha; Ahn, Wha-Seung

    2013-10-01

    A low cost bentonite was modified with PEI (polyethylenimine) through a physical impregnation method. Bentonite in its natural state and after amine modification were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy, X-ray diffraction, N2 adsorption-desorption isotherms, and investigated for CO2 capture using a thermogravimetric analysis unit connected to a flow panel. The effect of adsorption temperature, PEI loading and CO2 partial pressure on the CO2 capture performance of the PEI-modified bentonite was examined. A cyclic CO2 adsorption-desorption test was also carried out to assess the stability of PEI-modified bentonite as a CO2 adsorbent. Bentonite in its natural state showed negligible CO2 uptake. After amine modification, the CO2 uptake increased significantly due to CO2 capture by amine species introduced via chemisorption. The PEI-modified bentonites showed high CO2 capture selectivity over N2, and exhibited excellent stability in cyclic CO2 adsorption-desorption runs.

  1. Will atmospheric CO2 concentration continue to increase if anthropogenic CO2 emissions cease?

    NASA Astrophysics Data System (ADS)

    MacDougall, A. H.; Eby, M.; Weaver, A. J.

    2013-12-01

    If anthropogenic CO2 emissions were to suddenly cease, the evolution of the atmospheric CO2 concentration would depend on the magnitude and sign of natural carbon sources and sinks. Experiments using Earth system models indicate that overall carbon sinks would dominate. However, these models have typically neglected the permafrost carbon pool, which has the potential to introduce an additional terrestrial source of carbon to the atmosphere. Here we use the University of Victoria Earth System Climate Model, which has recently been expanded to include permafrost carbon stocks and exchanges with the atmosphere. In a scenario of zeroed CO2 and sulphate aerosol emissions, we assess whether the warming induced by specified constant concentrations of non-CO2 greenhouse gases could slow the CO2 decline following zero emissions, or even reverse this trend and cause CO2 to increase over time. We find that a radiative forcing from non-CO2 gases of approximately 0.6 W m-2 results in a near balance of CO2 emissions from the terrestrial biosphere and uptake of CO2 by the oceans, resulting in near-constant atmospheric CO2 concentrations for at least a century after emissions are eliminated. At higher values of non-CO2 radiative forcing, CO2 concentrations increase over time, regardless of when emissions cease during the 21st century. Given that the present-day radiative forcing from non-CO2 greenhouse gases is about 0.95 W m-2, our results suggest that if we were to eliminate all CO2 and aerosols emissions without also decreasing non-CO2 greenhouse gas emissions, CO2 levels would increase over time, resulting in a small increase in climate warming. The sudden and total cessation of anthropogenic CO2 emissions is an unlikely future scenario. However, such cessation experiments provide a useful method for evaluating the relative strength of the terrestrial and oceanic carbon cycle feedbacks in the presence of forcing from non-CO2 greenhouse gasses.

  2. Global CO2 simulation using GOSAT-based surface CO2 flux estimates

    NASA Astrophysics Data System (ADS)

    Takagi, H.; Oda, T.; Saito, M.; Valsala, V.; Belikov, D.; Saeki, T.; Saito, R.; Morino, I.; Uchino, O.; Yoshida, Y.; Yokota, Y.; Bril, A.; Oshchepkov, S.; Andres, R. J.; Maksyutov, S.

    2012-04-01

    Investigating the distribution and temporal variability of surface CO2 fluxes is an active research topic in the field of contemporary carbon cycle dynamics. The technique central to this effort is atmospheric inverse modeling with which surface CO2 fluxes are estimated by making corrections to a priori flux estimates such that mismatches between model-predicted and observed CO2 concentrations are minimized. Past investigations were carried out by utilizing CO2 measurements collected in global networks of surface-based monitoring sites. Now, datasets of column-averaged CO2 dry air mole fraction (XCO2) retrieved from spectral soundings collected by GOSAT are available for complementing the surface-based CO2 observations. These space-based XCO2 data are expected to enhance the spatiotemporal coverage of the existing surface observation network and thus reduce uncertainty associated with the surface flux estimates. We estimated monthly CO2 fluxes in 64 sub-continental regions from a subset of the surface-based GLOBALVIEW CO2 data and the GOSAT FTS SWIR Level 2 XCO2 retrievals. We further simulated CO2 concentrations in 3-D model space using the surface flux estimates obtained. In this presentation, we report the result of a comparison between the simulated CO2 concentrations and independent surface observations. As part of an effort in inter-comparing GOSAT-based surface CO2 flux estimates, we also look at results yielded with XCO2 data retrieved with the PPDF-DOAS algorithm and those made available by the NASA Atmospheric CO2 Observations from Space team. For this study, we used version 08.1 of the National Institute for Environmental Studies atmospheric transport model, which was driven by the Japan Meteorological Agency's JCDAS wind analysis data. The CO2 forward simulations were performed on 2.5° × 2.5° horizontal grids at 32 vertical levels between the surface and the top of the atmosphere. The a priori flux dataset used was comprised of the sum of four

  3. CO2 laser ablation of lymphangioma circumscriptum of the scrotum.

    PubMed

    Treharne, Linda J; Murison, Maxwell S C

    2006-01-01

    Lymphangioma circumscriptum (LC) is an uncommon skin condition characterized by large muscular-coated lymphatic cisterns that lie deep with in the subcutaneous tissue and communicate with dilated dermal lymphatics. Patients suffer from edema and lymphatic leakage. Surgical excision and reconstruction is the gold standard for therapy. However, this can be mutilating. The authors present a patient who suffered widespread disease of his scrotum who had excellent symptomatic relief by treatment with the CO(2) laser.

  4. Effective CO2 adsorption on pristine and chemically functionalized MWCNTs

    NASA Astrophysics Data System (ADS)

    Shukrullah, Shazia; Mohamed, Norani Muti; Shaharun, Maizatul Shima; Ullah, Sami; Naz, Muhammad Yasin

    2016-11-01

    Carbon dioxide is one of the major greenhouse gases, which directly links to global warming. In this study, the laboratory produced multi-walled carbon nanotubes (MWCNTs) were amine-functionalized and tested for their potential as a CO2 adsorbent material. The CVD grown MWCNTs were treated with H2SO4/HNO3 and functionalized with 30% of 3-aminopropyltriethoxysilane (APTS). Both the pristine and functionalized MWCNTs were characterized for their surface morphology, chemical composition and functional groups by using FESEM, EDX and FTIR techniques. The acidic and APTS treatment to MWCNTs resulted in unbundling and loosening of the nanotubes from their bundled, agglomerated and entangled forms. Furthermore, oxidation and functionalization also significantly influenced the CO2 adsorption capacity of MWCNTs. The breakthrough curves (adsorption isotherms) revealed that the modified MWCNTs exhibit higher capacity for CO2 adsorption as compared to the pristine MWCNTs. Overall, CO2 uptake by the pristine and modified MWCNTs was found about 0.00025 mol/g and 0.00038 mol/g, respectively.

  5. Commitment accounting for CO2 emissions

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; Socolow, R. H.

    2013-12-01

    Long-lived energy infrastructure that burns fossil fuels represents a multi-decade 'commitment' to emit CO2. Today's global power sector, alone, represents hundreds of billions of tons of still unrealized 'committed emissions' of CO2. And every year, substantial new commitments to future emissions are made, as new power plants are built. The socioeconomic inertia of these commitments is a major barrier to climate change mitigation. Here, we quantify these annual commitments by a bottom-up analysis of all power plants commissioned between 1950 and 2011; assigning emission commitments to the year when each generator came on line. We find, assuming 40-year commitments, that the global commitment to future emissions from the world's generators in 2011 (the most recent year in our analysis) was 318 Gt CO2, of which 216 Gt CO2 were commitments from the world's coal-fired generators and 134 Gt CO2 were commitments from China's generators. Annual new global commitments exceeded 15 Gt CO2 per year in every year since 2000. Moreover, between 2005-2010 (the latest year of available emissions data), new global commitments were more than twice as large as actual emissions from all power plants. Country-specific ratios of new committed emissions to actual emissions, averaged over 1990-2010 were 4.1 for China, 2.6 for India, 0.9 for the EU, and 0.6 for the US. We urge that the reporting of annual CO2 emissions, already widely institutionalized, be augmented by 'commitment accounting' which makes these future emissions salient. Annual committed emissions and annual emissions of primary power infrastructure. New committed emissions (light green) have grown from approximately 4 Gt CO2 per year in 1960 to roughly 10 Gt CO2 per year between 1970-1995, and then to more than 15 Gt CO2 per year since 2000. Throughout this period, new committed emissions have exceeded annual emissions (blue curve, source: IEA). Although the commitments made 30-40 years ago have largely been realized (dark

  6. Precursory volcanic CO2 signals from space

    NASA Astrophysics Data System (ADS)

    Schwandner, Florian M.; Carn, Simon A.; Kataoka, Fumie; Kuze, Akihiko; Shiomi, Kei; Goto, Naoki

    2016-04-01

    Identification of earliest signals heralding volcanic unrest benefits from the unambiguous detection of precursors that reflect deviation of magmatic systems from metastable background activity. Ascent and emplacement of new basaltic magma at depth may precede eruptions by weeks to months. Transient localized carbon dioxide (CO2) emissions stemming from exsolution from depressurized magma are expected, and have been observed weeks to months ahead of magmatic surface activity. Detecting such CO2 precursors by continuous ground-based monitoring operations is unfortunately not a widely implemented method yet, save a handful of volcanoes. Detecting CO2 emissions from space offers obvious advantages - however it is technologically challenging, not the least due to the increasing atmospheric burden of CO2, against which a surface emission signal is hard to discern. In a multi-year project, we have investigated the feasibility of space-borne detection of pre-eruptive volcanic CO2 passive degassing signals using observations from the Greenhouse Gas Observing SATellite (GOSAT). Since 2010, we have observed over 40 active volcanoes from space using GOSAT's special target mode. Over 72% of targets experienced at least one eruption over that time period, demonstrating the potential utility of space-borne CO2 observations in non-imaging target-mode (point source monitoring mode). While many eruption precursors don't produce large enough CO2 signals to exceed space-borne detection thresholds of current satellite sensors, some of our observations have nevertheless already shown significant positive anomalies preceding eruptions at basaltic volcanoes. In 2014, NASA launched its first satellite dedicated to atmospheric CO2 observation, the Orbiting Carbon Observatory (OCO-2). Its observation strategy differs from the single-shot GOSAT instrument. At the expense of GOSAT's fast time series capability (3-day repeat cycle, vs. 16 for OCO-2), its 8-footprint continuous swath can slice

  7. Evaluation of CO2 Sorption Capacity of Granite for CO2 Geological Sequestration

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Sato, Y.; Lin, H.; Sasaki, K.; Takahashi, T.; Inomata, H.; Hashida, T.

    2007-03-01

    Anthropogenic effects on climate can be mitigated through various measures. Among them being CO2 sequestration into geological reservoirs including deep saline aquifers, depleted oil/gas reservoirs and coal seams are interested in a powerful means for drastically reducing emissions of CO2. When CO2 would be injected into geological reservoir, it should be necessary to know the potential of CO2 storing into the reservoir. In this study, amount of CO2 sorption of granite was to evaluate experimentally at temperatures 50, 70, 100 and 200°C and pressure up to 20 MPa using a magnetic suspension balance (MSB), which allows to measure under supercritical condition. As a result, we confirmed that the granite have the potential of CO2 sorption. Sorption isotherms obtained from the MSB experiment showed that amount of CO2 sorption increased with the increasing pressure and decreased with the increasing temperature for all experimental conditions. Especially, amount of CO2 sorption at 50°C compared with that at other temperatures (70, 100 and 200°C) increased rapidly in the vicinity of the critical state. In addition, the granite showed a maximum of CO2 sorption into granite could reach up to about 1.0% by weight at 50°C and 14.4MPa. The present results may provide a fundamental knowledge for the development of CO2 geological sequestration technology.

  8. Primary, secondary, and tertiary amines for CO2 capture: designing for mesoporous CO2 adsorbents.

    PubMed

    Ko, Young Gun; Shin, Seung Su; Choi, Ung Su

    2011-09-15

    CO(2) emissions, from fossil-fuel-burning power plants, the breathing, etc., influence the global worming on large scale and the man's work efficiency on small scale. The reversible capture of CO(2) is a prominent feature of CO(2) organic-inorganic hybrid adsorbent to sequester CO(2). Herein, (3-aminopropyl) trimethoxysilane (APTMS), [3-(methylamino)propyl] trimethoxysilane (MAPTMS), and [3-(diethylamino) propyl] trimethoxysilane (DEAPTMS) are immobilized on highly ordered mesoporous silicas (SBA-15) to catch CO(2) as primary, secondary, and tertiary aminosilica adsorbents. X-ray photoelectron spectroscopy was used to analyze the immobilized APTMS, MAPTMS, and DEAPTMS on the SBA-15. We report an interesting discovery that the CO(2) adsorption and desorption on the adsorbent depend on the amine type of the aminosilica adsorbent. The adsorbed CO(2) was easily desorbed from the adsorbent with the low energy consumption in the order of tertiary, secondary, and primary amino-adsorbents while the adsorption amount and the bonding-affinity increased in the reverse order. The effectiveness of amino-functionalized (1(o), 2(o), and 3(o) amines) SBA-15s as a CO(2) capturing agent was investigated in terms of adsorption capacity, adsorption-desorption kinetics, and thermodynamics. This work demonstrates apt amine types to catch CO(2) and regenerate the adsorbent, which may open new avenues to designing "CO(2) basket".

  9. Exercise carbon dioxide (CO2) retention with inhaled CO2 and breathing resistance.

    PubMed

    Shykoff, Barbara E; Warkander, Dan E

    2012-01-01

    Combined effects on respiratory minute ventilation (VE)--and thus, on end-tidal carbon dioxide partial pressure (P(ET)CO2)--of breathing resistance and elevated inspired carbon dioxide (CO2) had not been determined during heavy exercise. In this Institutional Review Board-approved, dry, sea-level study, 12 subjects in each of three phases exercised to exhaustion at 85% peak oxygen uptake while V(E) and P(ET)CO2 were measured. Participants inhaled 0%, 1%, 2% or 3% CO2 in air, or 0% or 2% CO2 in oxygen, with or without breathing resistance, mimicking the U.S. Navy's MK 16 rebreather underwater breathing apparatus (UBA). Compared to air baseline (0% inspired CO2 in air without resistance): (1) Oxygen decreased baseline V(E) (p < 0.01); (2) Inspired CO2 increased V(E) and P(ET)CO2 (p < 0.01); (3) Resistance decreased V(E) (p < 0.01); (4) Inspired CO2 with resistance elevated P(ET)CO2 (p < 0.01). In air, V(E) did not change from that with resistance alone. In oxygen, V(E) returned to oxygen baseline. End-exercise P(ET)CO2 exceeded 60 Torr (8.0 kPa) in three tests. Subjects identified hypercapnia poorly. Results support dual optimization of arterial carbon dioxide partial pressure and respiratory effort. Because elevated CO2 may not increase V(E) if breathing resistance and VE are high, rebreather UBA safety requires very low inspired CO2.

  10. Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

    NASA Astrophysics Data System (ADS)

    Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

    2016-04-01

    In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

  11. Computational comparison of the reactions of substituted amines with CO(2).

    PubMed

    Mindrup, Elaine M; Schneider, William F

    2010-08-23

    Substituted amines are a popular choice as molecules to selectively react with and separate CO(2) from gas mixtures. Such separations are of particular interest, for example, for CO(2) separations for carbon capture and sequestration. It is desirable to tune amine-CO(2) reaction energies to suit a particular separation. Herein, we use DFT-B3LYP simulations to characterize the products and energetics of reactions of CO(2) with a range of substituted amines, considering both 1:1 and 2:1 amine/CO(2) reaction stoichiometries. The results show that by adjusting both the nature and the placement of functional groups, it is possible to tune reaction energies over a substantial range. Decomposition of the 2:1 reaction into separate carbamate and ammonium formation steps shows that the Brønsted basicity and Lewis basicity towards CO(2) are largely uncorrelated and provide an independent means of tuning the overall reaction energies.

  12. Statistical analysis of liquid seepage in partially saturated heterogeneous fracture systems

    SciTech Connect

    Liou, Tai -Sheng

    1999-12-01

    Field evidence suggests that water flow in unsaturated fracture systems may occur along fast preferential flow paths. However, conventional macroscale continuum approaches generally predict the downward migration of water as a spatially uniform wetting front subjected to strong inhibition into the partially saturated rock matrix. One possible cause of this discrepancy may be the spatially random geometry of the fracture surfaces, and hence, the irregular fracture aperture. Therefore, a numerical model was developed in this study to investigate the effects of geometric features of natural rock fractures on liquid seepage and solute transport in 2-D planar fractures under isothermal, partially saturated conditions. The fractures were conceptualized as 2-D heterogeneous porous media that are characterized by their spatially correlated permeability fields. A statistical simulator, which uses a simulated annealing (SA) algorithm, was employed to generate synthetic permeability fields. Hypothesized geometric features that are expected to be relevant for seepage behavior, such as spatially correlated asperity contacts, were considered in the SA algorithm. Most importantly, a new perturbation mechanism for SA was developed in order to consider specifically the spatial correlation near conditioning asperity contacts. Numerical simulations of fluid flow and solute transport were then performed in these synthetic fractures by the flow simulator TOUGH2, assuming that the effects of matrix permeability, gas phase pressure, capillary/permeability hysteresis, and molecular diffusion can be neglected. Results of flow simulation showed that liquid seepage in partially saturated fractures is characterized by localized preferential flow, along with bypassing, funneling, and localized ponding. Seepage pattern is dominated by the fraction of asperity contracts, and their shape, size, and spatial correlation. However, the correlation structure of permeability field is less important

  13. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria.

    PubMed

    Okubo, Takashi; Liu, Dongyan; Tsurumaru, Hirohito; Ikeda, Seishi; Asakawa, Susumu; Tokida, Takeshi; Tago, Kanako; Hayatsu, Masahito; Aoki, Naohiro; Ishimaru, Ken; Ujiie, Kazuhiro; Usui, Yasuhiro; Nakamura, Hirofumi; Sakai, Hidemitsu; Hayashi, Kentaro; Hasegawa, Toshihiro; Minamisawa, Kiwamu

    2015-01-01

    A number of studies have shown that elevated atmospheric CO2 ([CO2]) affects rice yields and grain quality. However, the responses of root-associated bacteria to [CO2] elevation have not been characterized in a large-scale field study. We conducted a free-air CO2 enrichment (FACE) experiment (ambient + 200 μmol.mol(-1)) using three rice cultivars (Akita 63, Takanari, and Koshihikari) and two experimental lines of Koshihikari [chromosome segment substitution and near-isogenic lines (NILs)] to determine the effects of [CO2] elevation on the community structure of rice root-associated bacteria. Microbial DNA was extracted from rice roots at the panicle formation stage and analyzed by pyrosequencing the bacterial 16S rRNA gene to characterize the members of the bacterial community. Principal coordinate analysis of a weighted UniFrac distance matrix revealed that the community structure was clearly affected by elevated [CO2]. The predominant community members at class level were Alpha-, Beta-, and Gamma-proteobacteria in the control (ambient) and FACE plots. The relative abundance of Methylocystaceae, the major methane-oxidizing bacteria in rice roots, tended to decrease with increasing [CO2] levels. Quantitative PCR revealed a decreased copy number of the methane monooxygenase (pmoA) gene and increased methyl coenzyme M reductase (mcrA) in elevated [CO2]. These results suggest elevated [CO2] suppresses methane oxidation and promotes methanogenesis in rice roots; this process affects the carbon cycle in rice paddy fields.

  14. Infrared spectra and structures of the neutral and charged CrCO2 and Cr(CO2)2 isomers in solid neon.

    PubMed

    Zhang, Qingnan; Chen, Mohua; Zhou, Mingfei

    2014-08-07

    The reactions from codeposition of laser-ablated chromium atoms with carbon dioxide in excess neon are studied by infrared absorption spectroscopy. The species formed are identified by the effects of isotopic substitution on their infrared spectra. Density functional calculations are performed to support the spectral assignments and to interpret the geometric and electronic structures of the experimentally observed species. Besides the previously reported insertion products OCrCO and O2Cr(CO)2, the one-to-one Cr(CO2) complex and the one-to-two Cr(CO2)2 complex as well as the CrOCrCO and OCCrCO3 complexes are also formed. The Cr(CO2) complex is characterized to be side-on η(2)-C,O-coordinated. The Cr(CO2)2 complex is identified to involve a side-on η(2)-C,O-coordinated CO2 and an end-on η(1)-O-coordinated CO2. OCCrCO3 is a carbonate carbonyl complex predicted to have a planar structure with a η(2)-O,O-coordinated carbonate ligand. The CrOCrCO complex is predicted to be linear with a high-spin ground state. Besides the neutral molecules, charged species are also produced. The Cr(CO2)(+) and Cr(CO2)2(+) cation complexes are characterized to have linear end-on η(1)-O-coordinated structures with blue-shifted antisymmetric CO2 stretching vibrational frequencies. The OCrCO(-) anion is bent with the Cr-O and CO stretching frequencies red-shifted from those of OCrCO neutral molecule.

  15. Photolytic production of CO2 on Iapetus

    NASA Astrophysics Data System (ADS)

    Palmer, Eric; Brown, R. H.

    2008-09-01

    Carbon Dioxide has been detected on the surface of Iapetus by Cassini's VIMS instrument at the 4.26 micron band. This CO2 is concentrated on the equatorial leading side, where we also see an abundance of dark material. The residence time of free CO2 on the surface of Iapetus is very short, thus the CO2 is unlikely to be in the form of frost; it is more likely that the CO2 is tightly bound in the form of complexed molecules. We explore the possibility of photolytically generating CO2 from a mixture of the carbon rich material and water ice that matches the expected composition of the dark material on Iapetus' surface. An ice regolith was created with flash frozen water that was crushed into sub-millimeter shards and mixed with amorphous 13C. The regolith was placed in a vacuum chamber with a surface area of 10 cm2 and a thickness of 2 cm and exposed to UV light from a deuterium lamp with peaks of flux centered around 121 and 160 nm. Temperatures were varied between 60 and 130K at a pressure of 10-8 torr. Both CO and CO2 were produced by photolytic reactions and detected by a mass spectrometer. Applying these results to Iapetus, Jeans escape calculations show that CO2 generated by photolysis will remain gravitationally bound to Iapetus for between 100 and 200 years, ballistically scattering across the surface until it is sequestered in a polar cold trap or escapes to space. The average particle will interact with the surface more than 1000 times before escaping unless interactions with surface grains causes it to become complexed, such as adsorption. We are continuing to evaluate the photochemistry for this simulated Iapetus surface using a Nicolet IR spectrometer to identify all the products generated and estimate the associated production rate.

  16. Advanced CO2 Removal Technology Development

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Verma, Sunita; Forrest, Kindall; LeVan, M. Douglas

    2001-01-01

    The Advanced CO2 Removal Technical Task Agreement covers three active areas of research and development. These include a study of the economic viability of a hybrid membrane/adsorption CO2 removal system, sorbent materials development, and construction of a database of adsorption properties of important fixed gases on several adsorbent material that may be used in CO2 removal systems. The membrane/adsorption CO2 removal system was proposed as a possible way to reduce the energy consumption of the four-bed molecular sieve system now in use. Much of the energy used by the 4BMS is used to desorb water removed in the device s desiccant beds. These beds might be replaced by a desiccating membrane that moves the water from [he incoming stream directly into the outlet stream. The approach may allow the CO2 removal beds to operate at a lower temperature. A comparison between models of the 4BMS and hybrid systems is underway at Vanderbilt University. NASA Ames Research Center has been investigating a Ag-exchanged zeolites as a possible improvement over currently used Ca and Na zeolites for CO2 removal. Silver ions will complex with n:-bonds in hydrocarbons such as ethylene, giving remarkably improved selectivity for adsorption of those materials. Bonds with n: character are also present in carbon oxides. NASA Ames is also continuing to build a database for adsorption isotherms of CO2, N2, O2, CH4, and Ar on a variety of sorbents. This information is useful for analysis of existing hardware and design of new processes.

  17. Carbon Dioxide Clusters: (CO_2)_6 to (CO_2)13

    NASA Astrophysics Data System (ADS)

    McKellar, A. R. W.; Oliaee, J. Norooz; Dehghany, M.; Moazzen-Ahmadi, N.

    2011-06-01

    We recenty reported assignments of specific infrared bands in the CO_2 νb{3} region (˜2350 wn) to (CO_2)_6, (CO_2)_7, (CO_2)_9, (CO_2)10, (CO_2)11, (CO_2)12, and (CO_2)13. Spectra are obtained by direct absorption using a rapid-scan tuneable diode laser spectrometer to probe a pulsed supersonic slit-jet expansion and assignments are facilitated by recent calculations of Takeuchi based on the Murthy potential. (CO_2)_6 is a symmetric top with S_6 point group symmetry which can be thought of as a stack of two planar cyclic trimers. (CO_2)13 is also an S_6 symmetric top, and consists of a single CO_2 monomer surrounded by an slightly distorted icosahedral cage. The remaining clusters are asymmetric tops without symmetry. Here we report additional CO_2 cluster results. Calculations based on the SAPT-s potential indicate that the structure of (CO_2)10 may be slightly different from that given by Takeuchi/Murthy. An additional band is observed for each of (CO_2)13 and (CO_2)10. A feature observed at 2378.2 wn is assigned as a (CO_2)_6 parallel combination band involving the sum of a fundamental and a low-lying intermolecular vibration. Most significantly, two bands are assigned to a second isomer of (CO_2)_6. This is also a symmetric top, but now with S_4 symmetry. The two symmetric hexamer isomers observed spectroscopically correspond well with the lowest energy structures given by both the SAPT-s and Murthy intermolecular potentials. [1] J. Norooz Oliaee, M. Dehgany, N. Moazzen-Ahmadi, and A.R.W. McKellar, Phys. Chem. Chem. Phys. 13, 1297 (2011). [2] H. Takeuchi, J. Phys. Chem. A 107, 5703 (2008); C.S. Murthy, S.F. O'Shea, and I.R. McDonald, Mol. Phys. 50, 531 (1983). [3] R. Bukowski, J. Sadlej, B. Jeziorski, P. Jankowski, K. Szalewicz, S.A. Kucharski, H.L. Williams, and B.M. Rice, J. Chem. Phys. 110, 3785 (1999)

  18. Reactivity of rhodium(I) complexes bearing nitrogen-containing ligands toward CH3I: synthesis and full characterization of neutral cis-[RhX(CO)2(L)] and acetyl [RhI(μ-I)(COMe)(CO)(L)]2 complexes.

    PubMed

    Adcock, Romain J; Nguyen, Duc Hanh; Ladeira, Sonia; Le Berre, Carole; Serp, Philippe; Kalck, Philippe

    2012-08-20

    The neutral rhodium(I) square-planar complexes [RhX(CO)(2)(L)] [X = Cl (3), I (4)] bearing a nitrogen-containing ligand L [diethylamine (a), triethylamine (b), imidazole (c), 1-methylimidazole (d), pyrazole (e), 1-methylpyrazole (f), 3,5-dimethylpyrazole (g)] are straightforwardly obtained from L and [Rh(μ-X)(CO)(2)](2) [X = Cl (1), I (2)] precursors. The synthesis is extended to the diethylsulfide ligand h for 3h and 4h. According to the CO stretching frequency of 3 and 4, the ranking of the electronic density on the rhodium center follows the order b > a ≈ d > c > g > f ≈ h > e. The X-ray molecular structures of 3a, 3d-3f, 4a, and 4d-4f were determined. Results from variable-temperature (1)H and (13)C{(1)H} NMR experiments suggest a fluxional associative ligand exchange for 4c-4h and a supplementary hydrogen-exchange process in 4e and 4g. The oxidative addition reaction of CH(3)I to complexes 4c-4g affords the neutral dimeric iodo-bridged acetylrhodium(III) complexes [RhI(μ-I)(COCH(3))(CO)(L)](2) (6c-6g) in very good isolated yields, whereas 4a gives a mixture of neutral 6a and dianionic [RhI(2)(μ-I)(COCH(3))(CO)][NHMeEt(2)](2) and 4h exclusively provides the analogue dianionic complex with [SMeEt(2)](+) as the counterion. X-ray molecular structures for 6d(2) and 6e reveal that the two apical CO ligands are in mutual cis positions, as are the two apical d and e ligands, whereas isomer 6d(1) is centrosymmetric. Further reactions of 6d and 6e with CO or ligand e gave quantitatively the monomeric complexes [RhI(2)(COCH(3))(CO)(2)(d)] (7d) and [RhI(2)(COCH(3))(CO)(e)(2)] (8e), respectively, as confirmed by their X-ray structures. The initial rate of CH(3)I oxidative addition to 4 as determined by IR monitoring is dependent on the nature of the nitrogen-containing ligand. For 4a and 4h, reaction rates similar to those of the well-known rhodium anionic [RhI(2)(CO)(2)](-) species are observed and are consistent with the formation of this intermediate species

  19. Total (fumarolic + diffuse soil) CO2 output from Furnas volcano.

    PubMed

    Pedone, M; Viveiros, F; Aiuppa, A; Giudice, G; Grassa, F; Gagliano, A L; Francofonte, V; Ferreira, T

    Furnas volcano, in São Miguel island (Azores), being the surface expression of rising hydrothermal steam, is the site of intense carbon dioxide (CO2) release by diffuse degassing and fumaroles. While the diffusive CO2 output has long (since the early 1990s) been characterized by soil CO2 surveys, no information is presently available on the fumarolic CO2 output. Here, we performed (in August 2014) a study in which soil CO2 degassing survey was combined for the first time with the measurement of the fumarolic CO2 flux. The results were achieved by using a GasFinder 2.0 tunable diode laser. Our measurements were performed in two degassing sites at Furnas volcano (Furnas Lake and Furnas Village), with the aim of quantifying the total (fumarolic + soil diffuse) CO2 output. We show that, within the main degassing (fumarolic) areas, the soil CO2 flux contribution (9.2 t day(-1)) represents a minor (~15 %) fraction of the total CO2 output (59 t day(-1)), which is dominated by the fumaroles (~50 t day(-1)). The same fumaroles contribute to ~0.25 t day(-1) of H2S, based on a fumarole CO2/H2S ratio of 150 to 353 (measured with a portable Multi-GAS). However, we also find that the soil CO2 contribution from a more distal wider degassing structure dominates the total Furnas volcano CO2 budget, which we evaluate (summing up the CO2 flux contributions for degassing soils, fumarolic emissions and springs) at ~1030 t day(-1).

  20. Geologic CO2 Input Into Groundwater and the Atmosphere, Soda Springs, ID, USA

    SciTech Connect

    J. L. Lewicki; G. E. Hilley; L. Dobeck; T. L. McLing; B. M. Kennedy; M. Bill; B. D. V. Marino

    2013-02-01

    A set of CO2 flux, geochemical, and hydrologic measurement techniques was used to characterize the source of and quantify gaseous and dissolved CO2 discharges from the area of Soda Springs, southeastern Idaho. An eddy covariance system was deployed for approximately one month near a bubbling spring and measured net CO2 fluxes from - 74 to 1147 g m- 2 d- 1. An inversion of measured eddy covariance CO2 fluxes and corresponding modeled source weight functions mapped the surface CO2 flux distribution within and quantified CO2 emission rate (24.9 t d- 1) from a 0.05 km2 area surrounding the spring. Soil CO2 fluxes (< 1 to 52,178 g m- 2 d- 1) were measured within a 0.05 km2 area of diffuse degassing using the accumulation chamber method. The estimated CO2 emission rate from this area was 49 t d- 1. A carbon mass balance approach was used to estimate dissolved CO2 discharges from contributing sources at nine springs and the Soda Springs geyser. Total dissolved inorganic carbon (as CO2) discharge for all sampled groundwater features was 57.1 t d- 1. Of this quantity, approximately 3% was derived from biogenic carbon dissolved in infiltrating groundwater, 35% was derived from carbonate mineral dissolution within the aquifer(s), and 62% was derived from deep source(s). Isotopic compositions of helium (1.74–2.37 Ra) and deeply derived carbon (d13C approximately 3‰) suggested contribution of volatiles from mantle and carbonate sources. Assuming that the deeply derived CO2 discharge estimated for sampled groundwater features (approximately 35 t d- 1) is representative of springs throughout the study area, the total rate of deeply derived CO2 input into the groundwater system within this area could be ~ 350 t d- 1, similar to CO2 emission rates from a number of quiescent volcanoes.

  1. Impact of pressure and temperature on CO2-brine-mica contact angles and CO2-brine interfacial tension: Implications for carbon geo-sequestration.

    PubMed

    Arif, Muhammad; Al-Yaseri, Ahmed Z; Barifcani, Ahmed; Lebedev, Maxim; Iglauer, Stefan

    2016-01-15

    Precise characterization of wettability of CO2-brine-rock system and CO2-brine interfacial tension at reservoir conditions is essential as they influence capillary sealing efficiency of caprocks, which in turn, impacts the structural and residual trapping during CO2 geo-sequestration. In this context, we have experimentally measured advancing and receding contact angles for brine-CO2-mica system (surface roughness ∼12nm) at different pressures (0.1MPa, 5MPa, 7MPa, 10MPa, 15MPa, 20MPa), temperatures (308K, 323K, and 343K), and salinities (0wt%, 5wt%, 10wt%, 20wt% and 30wt% NaCl). For the same experimental matrix, CO2-brine interfacial tensions have also been measured using the pendant drop technique. The results indicate that both advancing and receding contact angles increase with pressure and salinity, but decrease with temperature. On the contrary, CO2-brine interfacial tension decrease with pressure and increase with temperature. At 20MPa and 308K, the advancing angle is measured to be ∼110°, indicating CO2-wetting. The results have been compared with various published literature data and probable factors responsible for deviations have been highlighted. Finally we demonstrate the implications of measured data by evaluating CO2 storage heights under various operating conditions. We conclude that for a given storage depth, reservoirs with lower pressures and high temperatures can store larger volumes and thus exhibit better sealing efficiency.

  2. Extent of Genetic Lesions of the Arginine and Pyrimidine Biosynthetic Pathways in Lactobacillus plantarum, L. paraplantarum, L. pentosus, and L. casei: Prevalence of CO2-Dependent Auxotrophs and Characterization of Deficient arg Genes in L. plantarum

    PubMed Central

    Bringel, Françoise; Hubert, Jean-Claude

    2003-01-01

    Lactic acid bacteria require rich media since, due to mutations in their biosynthetic genes, they are unable to synthesize numerous amino acids and nucleobases. Arginine biosynthesis and pyrimidine biosynthesis have a common intermediate, carbamoyl phosphate (CP), whose synthesis requires CO2. We investigated the extent of genetic lesions in both the arginine biosynthesis and pyrimidine biosynthesis pathways in a collection of lactobacilli, including 150 strains of Lactobacillus plantarum, 32 strains of L. pentosus, 15 strains of L. paraplantarum, and 10 strains of L. casei. The distribution of prototroph and auxotroph phenotypes varied between species. All L. casei strains, no L. paraplantarum strains, two L. pentosus strains, and seven L. plantarum strains required arginine for growth. Arginine auxotrophs were more frequently found in L. plantarum isolated from milk products than in L. plantarum isolated from fermented plant products or humans; association with dairy products might favor arginine auxotrophy. In L. plantarum the argCJBDF genes were functional in most strains, and when they were inactive, only one gene was mutated in more than one-half of the arginine auxotrophs. Random mutation may have generated these auxotrophs since different arg genes were inactivated (there were single point mutations in three auxotrophs and nonrevertible genetic lesions in four auxotrophs). These data support the hypothesis that lactic acid bacteria evolve by progressively loosing unnecessary genes upon adaptation to specific habitats, with genome evolution towards cumulative DNA degeneration. Although auxotrophy for only uracil was found in one L. pentosus strain, a high CO2 requirement (HCR) for arginine and pyrimidine was common; it was found in 74 of 207 Lactobacillus strains tested. These HCR auxotrophs may have had their CP cellular pool-related genes altered or deregulated. PMID:12732536

  3. CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

    PubMed Central

    Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

    2015-01-01

    Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

  4. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2

    NASA Technical Reports Server (NTRS)

    Kawa, Randy; Huisheng, Bian

    2004-01-01

    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  5. Spatial and temporal dynamics of CO2 partial pressure in the Yellow River, China

    NASA Astrophysics Data System (ADS)

    Ran, L.; Lu, X. X.; Richey, J. E.; Sun, H.; Han, J.; Yu, R.; Liao, S.; Yi, Q.

    2014-10-01

    Carbon transport in river systems is an important component of the global carbon cycle. Most rivers of the world act as atmospheric CO2 sources due to high riverine CO2 partial pressure (pCO2). We investigated the pCO2 dynamics in the Yellow River watershed by using historical water chemistry records (1950s-1984) and recent sampling along the mainstem (2011-2012). Except the headwater region where the pCO2 was lower than the atmospheric equilibrium (i.e., 380 μatm), river waters in the remaining watershed were supersaturated with CO2. The average pCO2 for the watershed was estimated at 2810 ± 1985 μatm, which is 7-fold the atmospheric equilibrium. This indicates a strong CO2 outgassing across the water-air interface. As a result of severe soil erosion and dry climate, waters from the Loess Plateau in the middle reaches had higher pCO2 than that from the upper and lower reaches. From a seasonal perspective, the pCO2 varied from about 200 μatm to >30 000 μatm with higher pCO2 usually occurring in the dry season and low pCO2 in the wet season (at 73% of the sampling sites), suggesting the dilution effect of water. While the pCO2 responded positively to total suspended solids (TSS) transport when the TSS was less than 100 kg m-3, it slightly decreased and remained stable when the TSS exceeded 100 kg m-3. This stable pCO2 is largely due to gully erosion that mobilizes subsoils characterized by low organic matter for decomposition. In addition, human activities have changed the pCO2 dynamics. Particularly, flow regulation by dams can diversely affect the temporal changes of pCO2, depending on the physiochemical properties of the regulated waters and adopted operation scheme. Given the high pCO2 in the Yellow River waters, the resultant CO2 outgassing is expected to be substantial and warrants further investigation.

  6. Monitoring of near surface CO2

    NASA Astrophysics Data System (ADS)

    Faber, E.; Möller, I.; Teschner, M.; Poggenburg, J.; Spickenbom, K.; Schulz, H. J.

    2009-04-01

    Monitoring of near surface CO2 ECKHARD FABER1, INGO MÖLLER1, MANFRED TESCHNER1, JÜRGEN POGGENBURG1, KAI SPICKENBOM1, HANS-MARTIN SCHULZ1,2 1Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, D-30655 Hannover, e.faber@bgr.de 2present adress: GeoForschungsZentrum Potsdam (GFZ), Telegrafenberg, D-14473 Potsdam Underground gas storage and sequestration of carbon dioxide is one of the methods to reduce the input of antropogenic CO2 into the atmosphere and its greenhouse effect. Storage of CO2 is planned in depleted reservoirs, in aquifers and in salt caverns. Storage sites must have very small leakage rates to safely store the CO2 for centuries. Thus, a careful investigation and site selection is crucial. However, any leakage of CO2 to the surface is potentially dangerous for humans and environment. Therefore, instruments and systems for the detection of any CO2 escaping the storage sites and reaching the atmosphere have to be developed. Systems to monitor gases in deep wells, groundwater and surface sediments for leaking CO2 are developed, tested and are contnuously improved. Our group is mainly analysing CO2 in shallow (down to 3 m) soil samples using automatically operating monitoring systems. The systems are equipped with sensors to measure CO2 (and other gases) concentrations and other environmental parameters (atmospheric pressure, ambient and soil temperatures, etc.). Data are measured in short intervals (minute to subminute), are stored locally and are transferred by telemetrical systems into the BGR laboratory (Weinlich et al., 2006). In addition to soil gases monitoring systems technical equipment is available for continuous underwater gas flow measurements. Several of those monitoring systems are installed in different areas like Czech Republic, Austria, Italy and Germany. To detect any leaking gas from a sequestration site after CO2 injection, the naturally existing CO2 concentration (before injection) must be known. Thus, the natural

  7. Validation of Airborne CO2 Laser Measurements

    NASA Astrophysics Data System (ADS)

    Browell, E. V.; Dobler, J. T.; Kooi, S.; Fenn, M. A.; Choi, Y.; Vay, S. A.; Harrison, F. W.; Moore, B.; Zaccheo, T. S.

    2010-12-01

    This paper discusses the flight test validation of a unique, multi-frequency, intensity-modulated, single-beam laser absorption spectrometer (LAS) that operates near 1.57 μm for remote column CO2 measurements. This laser system is under development for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions during Nights, Days, and Seasons (ASCENDS) mission. A prototype of this LAS system, called the Multi-frequency Fiber Laser Lidar (MFLL), was developed by ITT, and it has been flight tested in nine airborne campaigns since May 2005. This paper focuses on the most recent results obtained over the last two years of flight-testing where the MFLL remote CO2 column measurements were evaluated against airborne in situ CO2 profile measurements traceable to World Meteorological Organization standards. A comprehensive multiple-aircraft flight test program was conducted over Oklahoma and Virginia in July-August 2009. The MFLL obtained surface reflectance and average CO2 column variations along the 50-km flight legs over the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Central Facility (CF) in Lamont, Oklahoma; over rural Virginia and North Carolina; and over the Chesapeake Bay. For a flight altitude of 4.6 km, the average signal to noise ratio (SNR) for a 1-s CO2 column measurement was found to be 760, which is the equivalent of a CO2 mixing ratio precision of 0.60 ppmv, and for a 10-s average the SNR was found to be 2002 or 0.20 ppmv. Absolute comparisons of MFLL-derived and in situ-derived CO2 column measurements were made for all daytime flights conducted over Oklahoma and Virginia with an average agreement to within 0.32 ppmv. A major ASCENDS flight test campaign was conducted using the NASA DC-8 during 6-18 July 2010. The MFLL system and associated in situ CO2 instrumentation were operated on DC-8 flights over the Central Valley

  8. Direct Copolymerization of CO2 and Diols

    NASA Astrophysics Data System (ADS)

    Tamura, Masazumi; Ito, Kazuki; Honda, Masayoshi; Nakagawa, Yoshinao; Sugimoto, Hiroshi; Tomishige, Keiichi

    2016-04-01

    Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification.

  9. Direct Copolymerization of CO2 and Diols

    PubMed Central

    Tamura, Masazumi; Ito, Kazuki; Honda, Masayoshi; Nakagawa, Yoshinao; Sugimoto, Hiroshi; Tomishige, Keiichi

    2016-01-01

    Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification. PMID:27075987

  10. The supply chain of CO2 emissions.

    PubMed

    Davis, Steven J; Peters, Glen P; Caldeira, Ken

    2011-11-08

    CO(2) emissions from the burning of fossil fuels are conventionally attributed to the country where the emissions are produced (i.e., where the fuels are burned). However, these production-based accounts represent a single point in the value chain of fossil fuels, which may have been extracted elsewhere and may be used to provide goods or services to consumers elsewhere. We present a consistent set of carbon inventories that spans the full supply chain of global CO(2) emissions, finding that 10.2 billion tons CO(2) or 37% of global emissions are from fossil fuels traded internationally and an additional 6.4 billion tons CO(2) or 23% of global emissions are embodied in traded goods. Our results reveal vulnerabilities and benefits related to current patterns of energy use that are relevant to climate and energy policy. In particular, if a consistent and unavoidable price were imposed on CO(2) emissions somewhere along the supply chain, then all of the parties along the supply chain would seek to impose that price to generate revenue from taxes collected or permits sold. The geographical concentration of carbon-based fuels and relatively small number of parties involved in extracting and refining those fuels suggest that regulation at the wellhead, mine mouth, or refinery might minimize transaction costs as well as opportunities for leakage.

  11. CO2 DIAL measurements of water vapor

    NASA Technical Reports Server (NTRS)

    Grant, William B.; Margolis, Jack S.; Brothers, Alan M.; Tratt, David M.

    1987-01-01

    CO2 lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microns, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO2 laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO2 lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficent for the 10P(14) CO2 laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO2 lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures.

  12. The supply chain of CO2 emissions

    PubMed Central

    Davis, Steven J.; Peters, Glen P.; Caldeira, Ken

    2011-01-01

    CO2 emissions from the burning of fossil fuels are conventionally attributed to the country where the emissions are produced (i.e., where the fuels are burned). However, these production-based accounts represent a single point in the value chain of fossil fuels, which may have been extracted elsewhere and may be used to provide goods or services to consumers elsewhere. We present a consistent set of carbon inventories that spans the full supply chain of global CO2 emissions, finding that 10.2 billion tons CO2 or 37% of global emissions are from fossil fuels traded internationally and an additional 6.4 billion tons CO2 or 23% of global emissions are embodied in traded goods. Our results reveal vulnerabilities and benefits related to current patterns of energy use that are relevant to climate and energy policy. In particular, if a consistent and unavoidable price were imposed on CO2 emissions somewhere along the supply chain, then all of the parties along the supply chain would seek to impose that price to generate revenue from taxes collected or permits sold. The geographical concentration of carbon-based fuels and relatively small number of parties involved in extracting and refining those fuels suggest that regulation at the wellhead, mine mouth, or refinery might minimize transaction costs as well as opportunities for leakage. PMID:22006314

  13. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden

    NASA Astrophysics Data System (ADS)

    Mau, S.; Römer, M.; Torres, M. E.; Bussmann, I.; Pape, T.; Damm, E.; Geprägs, P.; Wintersteller, P.; Hsu, C.-W.; Loher, M.; Bohrmann, G.

    2017-02-01

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming.

  14. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden.

    PubMed

    Mau, S; Römer, M; Torres, M E; Bussmann, I; Pape, T; Damm, E; Geprägs, P; Wintersteller, P; Hsu, C-W; Loher, M; Bohrmann, G

    2017-02-23

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02-7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming.

  15. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden

    PubMed Central

    Mau, S.; Römer, M.; Torres, M. E.; Bussmann, I.; Pape, T.; Damm, E.; Geprägs, P.; Wintersteller, P.; Hsu, C.-W.; Loher, M.; Bohrmann, G.

    2017-01-01

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming. PMID:28230189

  16. Measuring Nitrous Oxide Mass Transfer into Non-Aqueous CO2BOL CO2 Capture Solvents

    SciTech Connect

    Whyatt, Greg A.; Freeman, Charles J.; Zwoster, Andy; Heldebrant, David J.

    2016-03-28

    This paper investigates CO2 absorption behavior in CO2BOL solvents by decoupling the physical and chemical effects using N2O as a non-reactive mimic. Absorption measurements were performed using a wetted-wall contactor. Testing was performed using a “first generation” CO2 binding organic liquid (CO2BOL), comprised of an independent base and alcohol. Measurements were made with N2O at a lean (0.06 mol CO2/mol BOL) and rich (0.26 mol CO2/mol BOL) loading, each at three temperatures (35, 45 and 55 °C). Liquid-film mass transfer coefficients (kg') were calculated by subtracting the gas film resistance – determined from a correlation from literature – from the overall mass transfer measurement. The resulting kg' values for N2O in CO2BOLs were found to be higher than that of 5 M aqueous MEA under comparable conditions, which is supported by published measurements of Henry’s coefficients for N2O in various solvents. These results suggest that the physical solubility contribution for CO2 absorption in CO2BOLs is greater than that of aqueous amines, an effect that may pertain to other non-aqueous solvents.

  17. pCO2 and CO2 Exchange During High Bora Winds in the Northern Adriatic

    DTIC Science & Technology

    2013-03-05

    coastal ocean , has not been adequately assessed. Here we show the response of surfacewater pCO2 and CO2 fluxes during high borawind in the Northern...m−2 day−1 day in thewinter cases and 29 mmol m−2 day−1 in the summer case) over themag- nitude of the mean annual value. Oceanic data measured...simultaneously to surface pCO2 measurements suggest that themost likely responsiblemechanisms for the observed pCO2 increaseswere oceanic verticalmixing and

  18. Light-duty vehicle CO2 targets consistent with 450 ppm CO2 stabilization.

    PubMed

    Winkler, Sandra L; Wallington, Timothy J; Maas, Heiko; Hass, Heinz

    2014-06-03

    We present a global analysis of CO2 emission reductions from the light-duty vehicle (LDV) fleet consistent with stabilization of atmospheric CO2 concentration at 450 ppm. The CO2 emission reductions are described by g CO2/km emission targets for average new light-duty vehicles on a tank-to-wheel basis between 2010 and 2050 that we call CO2 glide paths. The analysis accounts for growth of the vehicle fleet, changing patterns in driving distance, regional availability of biofuels, and the changing composition of fossil fuels. New light-duty vehicle fuel economy and CO2 regulations in the U.S. through 2025 and in the EU through 2020 are broadly consistent with the CO2 glide paths. The glide path is at the upper end of the discussed 2025 EU range of 68-78 g CO2/km. The proposed China regulation for 2020 is more stringent than the glide path, while the 2017 Brazil regulation is less stringent. Existing regulations through 2025 are broadly consistent with the light-duty vehicle sector contributing to stabilizing CO2 at approximately 450 ppm. The glide paths provide long-term guidance for LDV powertrain/fuel development.

  19. CO2-Binding-Organic-Liquids-Enhanced CO2 Capture using Polarity-Swing-Assisted Regeneration

    SciTech Connect

    Zhang, Jian; Kutnyakov, Igor; Koech, Phillip K.; Zwoster, Andy; Howard, Chris; Zheng, Feng; Freeman, Charles J.; Heldebrant, David J.

    2013-01-01

    A new solvent-based CO2 capture process couples the unique attributes of non-aqueous, CO2-binding organic liquids (CO2BOLs) with the newly discovered polarity-swing-assisted regeneration (PSAR) process that is unique to switchable ionic liquids. Laboratory measurements with PSAR indicate the ability to achieve a regeneration effect at 75°C comparable to that at 120°C using thermal regeneration only. Initial measurements also indicate that the kinetic behavior of CO2 release is also improved with PSAR. Abstract cleared PNWD-SA-9743

  20. Behavior of CO2/water flow in porous media for CO2 geological storage.

    PubMed

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen

    2017-04-01

    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin(-1). For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO2 and water became miscible in the beginning of CO2 injection. CO2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO2 and water to invade into small pore spaces more easily. The study also showed CO2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO2 slightly decreases with the increase of capillary number.

  1. Metal-CO2 Batteries on the Road: CO2 from Contamination Gas to Energy Source.

    PubMed

    Xie, Zhaojun; Zhang, Xin; Zhang, Zhang; Zhou, Zhen

    2017-04-01

    Rechargeable nonaqueous metal-air batteries attract much attention for their high theoretical energy density, especially in the last decade. However, most reported metal-air batteries are actually operated in a pure O2 atmosphere, while CO2 and moisture in ambient air can significantly impact the electrochemical performance of metal-O2 batteries. In the study of CO2 contamination on metal-O2 batteries, it has been gradually found that CO2 can be utilized as the reactant gas alone; namely, metal-CO2 batteries can work. On the other hand, investigations on CO2 fixation are in focus due to the potential threat of CO2 on global climate change, especially for its steadily increasing concentration in the atmosphere. The exploitation of CO2 in energy storage systems represents an alternative approach towards clean recycling and utilization of CO2 . Here, the aim is to provide a timely summary of recent achievements in metal-CO2 batteries, and inspire new ideas for new energy storage systems. Moreover, critical issues associated with reaction mechanisms and potential directions for future studies are discussed.

  2. The Abundance of Atmospheric CO2 in Ocean Exoplanets: a Novel CO2 Deposition Mechanism

    NASA Astrophysics Data System (ADS)

    Levi, A.; Sasselov, D.; Podolak, M.

    2017-03-01

    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO2, the amount of CO2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO2. We find that, in a steady state, the abundance of CO2 in the atmosphere has two possible states. When wind-driven circulation is the dominant CO2 exchange mechanism, an atmosphere of tens of bars of CO2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO2 is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO2 into the atmosphere to increase the greenhouse effect.

  3. Potential Hydrogeomechanical Impacts of Geological CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    McPherson, B. J.; Haerer, D.; Han, W.; Heath, J.; Morse, J.

    2006-12-01

    Long-term sequestration of anthropogenic "greenhouse gases" such as CO2 is a proposed approach to managing climate change. Deep brine reservoirs in sedimentary basins are possible sites for sequestration, given their ubiquitous nature. We used a mathematical sedimentary basin model, including coupling of multiphase CO2-groundwater flow and rock deformation, to evaluate residence times in possible brine reservoir storage sites, migration patterns and rates away from such sites, and effects of CO2 injection on fluid pressures and rock strain. Study areas include the Uinta and Paradox basins of Utah, the San Juan basin of New Mexico, and the Permian basin of west Texas. Regional-scale hydrologic and mechanical properties, including the presence of fracture zones, were calibrated using laboratory and field data. Our initial results suggest that, in general, long-term (~100 years or more) sequestration in deep brine reservoirs is possible, if guided by robust structural and hydrologic data. However, specific processes must be addressed to characterize and minimize risks. In addition to CO2 migration from target sequestration reservoirs into other reservoirs or to the land surface, another environmental issue is displacement of brines into freshwater aquifers. We evaluated the potential for such unintended aquifer contamination by displacement of brines out of adjacent sealing layers such as marine shales. Results suggest that sustained injection of CO2 may incur significant brine displacement out of adjacent sealing layers, depending on the injection history, initial brine composition, and hydrologic properties of both reservoirs and seals. Model simulations also suggest that as injection-induced overpressures migrate, effective stresses may follow this migration under some conditions, as will associated rock strain. Such "strain migration" may lead to induced or reactivated fractures or faults, but can be controlled through reservoir engineering.

  4. CO2-Induced Acidification of the Laurentian Great Lakes

    NASA Astrophysics Data System (ADS)

    McKinley, G. A.; Phillips, J.; Bennington, V.; Bootsma, H. A.; Pilcher, D.; Sterner, R.; Urban, N. R.

    2013-12-01

    A number of studies indicate that air-water equilibration is the dominant control on pCO2 in several Great Lakes at annual timescales or longer. Assuming this is the case across all lakes at present and into the future, we show that pH will decline by 0.3-0.4 units through 2100 under a business-as-usual CO2 emission scenario. In a survey of the Great Lakes scientific community, 87% of respondents indicate that CO2-driven acidification is likely. The available pH data do not support these predicted trends, but limited sampling in an environment characterized by significant spatio-temporal variability, as well as significant measurement uncertainty, cast doubt on the ability of the historical pH record to resolve the predicted trends. Evaluation of the current sampling strategy using eddy-resolving numerical models of Lake Superior and Lake Michigan are key evidence that the current monitoring strategy is inadequate. In order to track long-term pH change and assess whether atmospheric CO2 will affect the Great Lakes like the oceans, a new approach to Great Lakes pH monitoring is required. Ecological impacts of CO2 acidification have not been studied for the Great Lakes, but potential effects can be gleaned from the literature. In addition, our qualitative and quantitative survey results suggest that processes such as fish recruitment, dreissenid mussel growth, and nutrient cycling may be sensitive to pH, but there is lack of consensus about the magnitude and overall significance of these effects.

  5. Implications of CO2 Geological Storage on Aquifers Autotrophic Communities

    NASA Astrophysics Data System (ADS)

    Dupraz, Sébastien; Fabbri, Antonin; Joulian, Catherine; Menez, Bénédicte; Gerard, Emanuelle; Henry, Benoit; Crouzet, Catherine; Guyot, François; Garrido, Francis

    2010-05-01

    In a global strategy of carbon emission reduction, a study about CCS (Carbon Capture and Storage) feasibility in the case of a French beet sugar factory and distillery in the Parisian basin was undertaken by regional and state authorities. Besides, economical, geological and engineering questions, microbial interactions were also studied since the potential contribution of the deep biosphere on the storage zones appears to be an essential factor in terms of injectivity and CO2 mobilization. Biological processes like biofilm formation, biomineralization and carbon assimilation may hinder the injections or, to the contrary, improve the stability of the sequestration by shifting CO2 into more stable forms like carbonates and organic matter. Regarding those possibilities, it is thus mandatory to establish how the subsurface biosphere will react by determining which metabolisms will be able to sustain the stress due to high concentrations of CO2 and the resulting acidification. In that case, the study of autotrophic communities reactivity is essential because they are the only entrance for CO2 assimilation in the SLiMEs (Subsurface Litho autotrophic Microbial Ecosystems) and thus are accountable for the general biomass and biofilm production in the deep subsurface. Nevertheless, a simple assessment of the toxical effect induced on these strains cannot be representative of the possible interactions at the scale of a long term storage where adaptations should play a major role. For that reason, we decided to choose different strains, namely autotrophic methanogens (Methanothermococcus thermolithotrophicus and Archeoglobus fulgidus) and sulfate reducing bacteria strains (Desulfotomaculum geothermicum and Desulfotomaculum kuznetsovii), that best characterize the autotrophic communities of our injection site (aquifer of the Triassic Keuper sandstones) and to make them undergo a test of selection/adaptation toward a sequential increase of CO2 partial pressure from 0.05 to 5

  6. Electrical Resistance Tomography Field Trials to Image CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Newmark, R.

    2003-12-01

    If geologic formations are used to sequester or store carbon dioxide (CO2) for long periods of time, it will be necessary to verify the containment of injected CO2 by assessing leaks and flow paths, and by understanding the geophysical and geochemical interactions between the CO2 and the geologic minerals and fluids. Remote monitoring methods are preferred, to minimize cost and impact to the integrity of the disposal reservoir. Electrical methods are especially well suited for monitoring processes involving fluids, as electrical properties are most sensitive to the presence and nature of the fluids contained in the medium. High resolution tomographs of electrical properties have been used with success for site characterization, monitoring subsurface migration of fluids in instances of leaking underground tanks, water infiltration events, subsurface steam floods, contaminant movement, and assessing the integrity of subsurface barriers. These surveys are commonly conducted utilizing vertical arrays of point electrodes in a crosswell configuration. Alternative ways of monitoring the reservoir are desirable due to the high costs of drilling the required monitoring boreholes Recent field results obtained using steel well casings as long electrodes are also promising. We have conducted field trials to evaluate the effectiveness of long electrode ERT as a potential monitoring approach for CO2 sequestration. In these trials, CO2 is not being sequestered but rather is being used as a solvent for enhanced oil recovery. This setting offers the same conditions expected during sequestration so monitoring secondary oil recovery allows a test of the method under realistic physical conditions and operational constraints. Field experience has confirmed the challenges identified during model studies. The principal difficulty are the very small signals due to the fact that formation changes occur only over a small segment of the 5000 foot length of the electrodes. In addition

  7. Photodissociation dynamics of IBr(-)(CO(2))(n), n<15.

    PubMed

    Sanford, Todd; Han, Sang-Yun; Thompson, Matthew A; Parson, Robert; Lineberger, W Carl

    2005-02-01

    We report the ionic photoproducts produced following photoexcitation of mass selected IBr(-)(CO(2))(n), n=0-14, cluster ions at 790 and 355 nm. These wavelengths provide single state excitation to two dissociative states, corresponding to the A(') (2)Pi(1/2) and B 2 (2)Sigma(1/2) (+) states of the IBr(-) chromophore. Excitation of these states in IBr(-) leads to production of I(-)+Br and Br(-)+I( *), respectively. Potential energy curves for the six lowest electronic states of IBr(-) are calculated, together with structures for IBr(-)(CO(2))(n), n=1-14. Translational energy release measurements on photodissociated IBr(-) determine the I-Br(-) bond strength to be 1.10+/-0.04 eV; related measurements characterize the A(') (2)Pi(1/2)<--X (2)Sigma(1/2) (+) absorption band. Photodissociation product distributions are measured as a function of cluster size following excitation to the A(') (2)Pi(1/2) and B 2 (2)Sigma(1/2) (+) states. The solvent is shown to drive processes such as spin-orbit relaxation, charge transfer, recombination, and vibrational relaxation on the ground electronic state. Following excitation to the A(') (2)Pi(1/2) electronic state, IBr(-)(CO(2))(n) exhibits size-dependent cage fractions remarkably similar to those observed for I(2) (-)(CO(2))(n). In contrast, excitation to the B 2 (2)Sigma(1/2) (+) state shows extensive trapping in excited states that dominates the recombination behavior for all cluster sizes we investigated. Finally, a pump-probe experiment on IBr(-)(CO(2))(8) determines the time required for recombination on the ground state following excitation to the A(') state. While the photofragmentation experiments establish 100% recombination in the ground electronic state for this and larger IBr(-) cluster ions, the time required for recombination is found to be approximately 5 ns, some three orders of magnitude longer than observed for the analogous I(2) (-) cluster ion. Comparisons are made with similar experiments carried out on I(2

  8. Membraneless water filtration using CO2

    NASA Astrophysics Data System (ADS)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  9. CO2 Orbital Trends in Comets

    NASA Astrophysics Data System (ADS)

    Kelley, Michael; Bodewits, Dennis; Feaga, Lori; Knight, Matthew; McKay, Adam; Snodgrass, Colin; Wooden, Diane

    2016-08-01

    Carbon dioxide is a primary volatile in comet nuclei, and potentially a major contributor to comet activity (i.e., the process of mass loss). However, CO2 cannot be observed directly from the ground, and past surveys of this molecule in comets were limited to space-borne snapshot observations. This situation limits our understanding of the behavior of CO2 in comets, and its role in driving comet mass loss. To address this deficiency, we were awarded a Cy11 Spitzer program designed to quantify the production rate of CO2 on >month-long timescales for 21 comets. We request an additional 269~hr in Cy13 to complete the Spitzer portion of our survey, and to add three more comets (46P/Wirtanen and 2 Target of Opportunity Oort cloud comets). Our survey is designed to probe the orbital trends of CO2 production in the comet population. We aim to: 1) examine the role of CO2 in the persistent post-perihelion activity observed in Jupiter-family comets; 2) measure the seasonal variations of CO2/H2O as a proxy for nucleus heterogeneity, when possible; 3) search for orbital trends sensitive to cumulative insolation as a proxy for nucleus layering; and 4) examine how Oort cloud comets evolve by comparing dynamically new and old targets. The final data set will allow us to investigate the effects of heating on the evolution of comets, if nucleus structures can be inferred through activity, and set the stage for JWST investigations into comet activity and composition.

  10. CO2 laser waveguiding in proton implanted GaAs

    NASA Technical Reports Server (NTRS)

    Jenkinson, H. A.; Larson, D. C.

    1981-01-01

    Surface layers capable of supporting optical modes at 10.6 microns have been produced in n-type GaAs wafers through 300 keV proton implantation. The dominant mechanism for this effect appears to be free carrier compensation. Characterization of the implanted layers by analysis of infrared reflectivity spectra and synchronous coupling at 10.6 microns produced results in good agreement with elementary models. These results of sample characterization by infrared reflectivity and by CO2 laser waveguiding as implanted are presented and evaluated.

  11. CO2 laser cutting of natural granite

    NASA Astrophysics Data System (ADS)

    Riveiro, A.; Mejías, A.; Soto, R.; Quintero, F.; del Val, J.; Boutinguiza, M.; Lusquiños, F.; Pardo, J.; Pou, J.

    2016-01-01

    Commercial black granite boards (trade name: "Zimbabwe black granite") 10 mm thick, were successfully cut by a 3.5 kW CO2 laser source. Cutting quality, in terms of kerf width and roughness of the cut wall, was assessed by means of statistically planned experiments. No chemical modification of the material in the cutting walls was detected by the laser beam action. Costs associated to the process were calculated, and the main factors affecting them were identified. Results reported here demonstrate that cutting granite boards could be a new application of CO2 laser cutting machines provided a supersonic nozzle is used.

  12. Leak Path Development in CO2 Wells

    NASA Astrophysics Data System (ADS)

    Torsater, M.; Todorovic, J.; Opedal, N.; Lavrov, A.

    2014-12-01

    Wells have in numerous scientific works been denoted the "weak link" of safe and cost-efficient CO2 Capture and Storage (CCS). Whether they are active or abandoned, all wells are man-made intrusions into the storage reservoir with sealing abilities depending on degradable materials like steel and cement. If dense CO2 is allowed to expand (e.g. due to leakage) it will cool down its surroundings and cause strong thermal and mechanical loading on the wellbore. In addition, CO2 reacts chemically with rock, cement and steel. To ensure long-term underground containment, it is therefore necessary to study how, why, where and when leakage occurs along CO2wells. If cement bonding to rock or casing is poor, leak paths can form already during drilling and completion of the well. In the present work, we have mapped the bonding quality of cement-rock and cement-steel interfaces - and measured their resistance towards CO2 flow. This involved a large experimental matrix including different rocks, steels, cement types and well fluids. The bonding qualities were measured on composite cores using micro computed tomography (µ-CT), and CO2 was flooded through the samples to determine leakage rates. These were further compared to numerical simulations of leakage through the digitalized µ-CT core data, and CO2chemical interactions with the materials were mapped using electron microscopy. We also present a new laboratory set-up for measuring how well integrity is affected by downhole temperature variations - and we showcase some initial results. Our work concludes that leak path development in CO2 wells depends critically on the drilling fluids and presflushes/spacers chosen already during drilling and completion of a well. Fluid films residing on rock and casing surfaces strongly degrade the quality of cement bonding. The operation of the well is also important, as even slight thermal cycling (between 10°C and 95°C on casing) leads to significant de-bonding of the annular cement.

  13. CO2 Acquisition Membrane (CAM) Project

    NASA Technical Reports Server (NTRS)

    Mason, L. W.; Way, J. D.; Vlasse, M.

    2001-01-01

    The CO2 Acquisition Membrane (CAM) project will develop, test, and analyze membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The CAM technology will enable passive separation of these gases, allow energy efficient acquisition and purification of these important resources, and lay the foundation for future unmanned sample return and human space missions. The CAM membranes are targeted toward In Situ Resource Utilization (ISRU) applications, such as In Situ Propellant Production (ISPP) and In Situ Consumables Production (ISCP).

  14. 10 MW Supercritical CO2 Turbine Test

    SciTech Connect

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  15. Crystallization of CO2 ice and the absence of amorphous CO2 ice in space

    PubMed Central

    Escribano, Rafael M.; Muñoz Caro, Guillermo M.; Cruz-Diaz, Gustavo A.; Rodríguez-Lazcano, Yamilet; Maté, Belén

    2013-01-01

    Carbon dioxide (CO2) is one of the most relevant and abundant species in astrophysical and atmospheric media. In particular, CO2 ice is present in several solar system bodies, as well as in interstellar and circumstellar ice mantles. The amount of CO2 in ice mantles and the presence of pure CO2 ice are significant indicators of the temperature history of dust in protostars. It is therefore important to know if CO2 is mixed with other molecules in the ice matrix or segregated and whether it is present in an amorphous or crystalline form. We apply a multidisciplinary approach involving IR spectroscopy in the laboratory, theoretical modeling of solid structures, and comparison with astronomical observations. We generate an unprecedented highly amorphous CO2 ice and study its crystallization both by thermal annealing and by slow accumulation of monolayers from the gas phase under an ultrahigh vacuum. Structural changes are followed by IR spectroscopy. We also devise theoretical models to reproduce different CO2 ice structures. We detect a preferential in-plane orientation of some vibrational modes of crystalline CO2. We identify the IR features of amorphous CO2 ice, and, in particular, we provide a theoretical explanation for a band at 2,328 cm−1 that dominates the spectrum of the amorphous phase and disappears when the crystallization is complete. Our results allow us to rule out the presence of pure and amorphous CO2 ice in space based on the observations available so far, supporting our current view of the evolution of CO2 ice. PMID:23858474

  16. CO2 lasers: beam patterns in relation to surgical use.

    PubMed

    Fava, G; Emanuelli, H; Cascinelli, N; Bandieramonte, G; Canestri, F; Marchesini, R

    1983-01-01

    According to surgeons operating with a variety of CO2 lasers available at the National Cancer Institute of Milan (Coherent, Sharplan, Valfivre), these lasers have different cutting and coagulation properties. To identify what physical parameters might corroborate the subjective impression of the surgeons, a comparative study of the crater forms in perspex samples was performed. Perspex was chosen for its thermal properties (in fact, its thermal conductivity and diffusivity are similar to those of organic tissue) and because it allowed good visualization and measurement of crater characteristics. Depth of penetration, crater diameter, and extension of thermal damage were measured against power, focal length, and exposure time for each CO2 laser model. These results can be used as an index of behaviour of different surgical lasers. It appears that for fully characterizing the interaction of surgical lasers with the sample, it is necessary to specify either power, focal length, exposure time, or beam mode.

  17. Significant alleviation of Darier's disease with fractional CO2 laser.

    PubMed

    Benmously, Rym; Litaiem, Noureddine; Hammami, Houda; Badri, Talel; Fenniche, Samy

    2015-04-01

    Darier's disease (DD) is a dominantly inherited genodermatosis with highly variable expression. It is characterized by symmetrical hyperkeratotic papules affecting seborrheic areas and extremities. The existence of unsightly lesions could lead to discomfort and social handicap. Conventional treatment consists of topical and systemic steroids and/or retinoids alleviating DD. Ablative lasers also have been used to treat these conditions with variable results and side effects. To the best of our knowledge, fractional CO2 laser has never been used to treat DD. We present a case of a 36-year-old woman with verrucous and hyperkeratotic plaques of the forehead significantly improved after two sessions of fractional CO2 laser treatment. Neither scars nor pigmentary disorders were noted.

  18. The Mars Diurnal CO2 Cycle as Observed in the Tharsis Region.

    NASA Astrophysics Data System (ADS)

    Titus, T. N.; Cushing, G. E.

    2014-12-01

    The Mars atmosphere is composed of 95% CO2, 25% of which is cycled through the seasonal CO2 ice caps annually. During the polar night, surface temperatures drop to ~145 K and CO2 ice can begin to directly condense. Also, atmospheric temperatures can drop even lower, allowing for the formation of CO2 snow. During the spring, the CO2 ice sublimes thus completing the annual CO2 cycle. While significant study has been conducted to characterize and model the annual CO2 cycle, little has been done to investigate the possibility of a diurnal CO2 cycle.There are two general locations where the diurnal exchange of surface CO2 ice with the atmosphere can occur: (1) the higher elevations of the Tharsis region and (2) the edges of the seasonal polar caps. This presentation will focus on the Tharsis region. The low surface thermal inertia, due to a thick layer of dust, and the low atmospheric pressure of the Tharsis region allow for diurnal temperature ranges from at or near the CO2 frost temperature (~140 K at 2 mbar) during pre-dawn hours to temperatures above the triple point of water during mid-day. The Mars Global Surveyor Thermal Emission Spectrometer showed evidence of CO2 ice deposition near the summit of Olympus Mons at 2 am local time. Spectra from the coldest data observed are generally flat through the 25 μm region, suggesting slab or coarse grained CO2 ice. The 15 μm region of the spectra shows a warm atmosphere, suggesting that the formation of CO2 snow is unlikely. The Mars Odyssey Thermal Emission Imaging System showed consistently that much of the surface is at or near the frost point of CO2, suggesting the possible widespread presence of CO2 ice deposits during the pre-dawn hours.Simple energy balance considerations suggest that a nightly CO2 deposit that completely sublimes away shortly after dawn, could be as thick as 1.6 kg/m3 (~1 mm if deposit is slab ice with no porosity). Further constraints on the details of the Tharsis diurnal CO2 cycle will be

  19. Progress Toward Measuring CO2 Isotopologue Fluxes in situ with the LLNL Miniature, Laser-based CO2 Sensor

    NASA Astrophysics Data System (ADS)

    Osuna, J. L.; Bora, M.; Bond, T.

    2015-12-01

    One method to constrain photosynthesis and respiration independently at the ecosystem scale is to measure the fluxes of CO2­ isotopologues. Instrumentation is currently available to makes these measurements but they are generally costly, large, bench-top instruments. Here, we present progress toward developing a laser-based sensor that can be deployed directly to a canopy to passively measure CO2 isotopologue fluxes. In this study, we perform initial proof-of-concept and sensor characterization tests in the laboratory and in the field to demonstrate performance of the Lawrence Livermore National Laboratory (LLNL) tunable diode laser flux sensor. The results shown herein demonstrate measurement of bulk CO2 as a first step toward achieving flux measurements of CO2 isotopologues. The sensor uses a Vertical Cavity Surface Emitting Laser (VCSEL) in the 2012 nm range. The laser is mounted in a multi-pass White Cell. In order to amplify the absorption signal of CO2 in this range we employ wave modulation spectroscopy, introducing an alternating current (AC) bias component where f is the frequency of modulation on the laser drive current in addition to the direct current (DC) emission scanning component. We observed a strong linear relationship (r2 = 0.998 and r2 = 0.978 at all and low CO2 concentrations, respectively) between the 2f signal and the CO2 concentration in the cell across the range of CO2 concentrations relevant for flux measurements. We use this calibration to interpret CO2 concentration of a gas flowing through the White cell in the laboratory and deployed over a grassy field. We will discuss sensor performance in the lab and in situ as well as address steps toward achieving canopy-deployed, passive measurements of CO2 isotopologue fluxes. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-675788

  20. Geologic Storage of CO2: Leakage Pathways and Environmental Risks

    NASA Astrophysics Data System (ADS)

    Celia, M. A.; Peters, C. A.; Bachu, S.

    2002-05-01

    of the overall storage scheme and contributes to possible climate change. To characterize these environmental consequences, reliable models of leakage characteristics and rates are needed. While leakage through natural flowpaths in the subsurface may occur, a more likely pathway is leakage through abandoned wells. This may be especially troublesome in mature sedimentary basins, which are often "punctured" by a very large number of exploration and production wells. For example, in the Alberta Basin there are more than 100,000 abandoned wells, the oldest from 1883. The cement used in the completion and abandonment of these wells, historically of variable quality and quantity, most probably has degraded with age and under the effect of formation brines. The cement may degrade even more rapidly when contacted by CO2 and possibly other components in the injection mixture (such as H2S). Cement properties and their modification through time must be understood in order to provide reliable estimates of leakage rates. Those leakage rates must then be linked to models of environmental consequences, and ultimately the entire analysis must be embedded in a probabilistic framework. Such an approach will allow leakage to be addressed rationally in terms of safety and long-term environmental impacts.

  1. Experimental investigation of CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.J.; Koksalan, T.; Palandri, J.L.

    2005-01-01

    Deep-saline aquifers are potential repositories for excess CO2, currently being emitted to the atmosphere from anthropogenic activities, but the reactivity of supercritical CO2 with host aquifer fluids and formation minerals needs to be understood. Experiments reacting supercritical CO2 with natural and synthetic brines in the presence and absence of limestone and plagioclase-rich arkosic sandstone showed that the reaction of CO2-saturated brine with limestone results in compositional, mineralogical, and porosity changes in the aquifer fluid and rock that are dependent on initial brine composition, especially dissolved calcium and sulfate. Experiments reacting CO2-saturated, low-sulfate brine with limestone dissolved 10% of the original calcite and increased rock porosity by 2.6%. Experiments reacting high-sulfate brine with limestone, both in the presence and absence of supercritical CO2, were characterized by the precipitation of anhydrite, dolomitization of the limestone, and a final decrease in porosity of 4.5%. However, based on favorable initial porosity changes of about 15% due to the dissolution of calcite, the combination of CO2 co-injection with other mitigation strategies might help alleviate some of the well-bore scale and formation-plugging problems near the injection zone of a brine disposal well in Paradox Valley, Colorado, as well as provide a repository for CO2. Experiments showed that the solubility of CO2 is enhanced in brine in the presence of limestone by 9% at 25 ??C and 6% at 120 ??C and 200 bar relative to the brine itself. The solubility of CO2 is enhanced also in brine in the presence of arkosic sandstone by 5% at 120 ??C and 300 bar. The storage of CO 2 in limestone aquifers is limited to only ionic and hydraulic trapping. However, brine reacted with supercritical CO2 and arkose yielded fixation and sequestration of CO2 in carbonate mineral phases. Brine desiccation was observed in all experiments containing a discrete CO2 phase

  2. High sensitivity to chronically elevated CO2 levels in a eurybathic marine sipunculid.

    PubMed

    Langenbuch, M; Pörtner, H O

    2004-10-18

    CO2 levels are expected to rise (a) in surface waters of the oceans as atmospheric accumulation continues or (b) in the deep sea, once industrial CO2 dumping is implemented. These scenarios suggest that CO2 will become a general stress factor in aquatic environments. The mechanisms of sensitivity to CO2 as well as adaptation capacity of marine animals are insufficiently understood. Here, we present data obtained in Sipunculus nudus, a sediment-dwelling marine worm that is able to undergo drastic metabolic depression to survive regular exposure to elevated CO2 levels within its natural habitat. We investigated animal survival and the proximate biochemical body composition during long-term CO2 exposure. Results indicate an unexpected and pronounced sensitivity characterized by the delayed onset of enhanced mortality at CO2 levels within the natural range of concentrations. Therefore, the present study contrasts the previously assumed high-CO2 tolerance of animals adapted to temporary hypercapnia. As a consequence, we expect future loss of species and, thereby, detrimental effects on marine benthic ecosystems with as yet poorly defined critical thresholds of long-term tolerance to CO2.

  3. Sensitivity analysis of a model of CO2 exchange in tundra ecosystems by the adjoint method

    SciTech Connect

    Waelbroek, C.; Louis, J.F. |

    1995-02-01

    A model of net primary production (NPP), decomposition, and nitrogen cycling in tundra ecosystems has been developed. The adjoint technique is used to study the sensitivity of the computed annual net CO2 flux to perturbation in initial conditions, climatic inputs, and model`s main parameters describing current seasonal CO2 exchange in wet sedge tundra at Barrow, Alaska. The results show that net CO2 flux is most sensitive to parameters characterizing litter chemical composition and more sensitive to decomposition parameters than to NPP parameters. This underlines the fact that in nutrient-limited ecosystems, decomposition drives net CO2 exchange by controlling mineralization of main nutrients. The results also indicate that the short-term (1 year) response of wet sedge tundra to CO2-induced warming is a significant increase in CO2 emission, creating a positive feedback to atmosphreic CO2 accumulation. However, a cloudiness increase during the same year can severely alter this response and lead to either a slight decrease or a strong increase in emitted CO2, depending on its exact timing. These results demonstrate that the adjoint method is well suited to study systems encountering regime changes, as a single run of the adjoint model provides sensitivities of the net CO2 flux to perturbations in all parameters and variables at any time of the year. Moreover, it is shown that large errors due to the presence of thresholds can be avoided by first delimiting the range of applicability of the adjoint results.

  4. Sensitivity analysis of a model of CO2 exchange in tundra ecosystems by the adjoint method

    NASA Technical Reports Server (NTRS)

    Waelbroek, C.; Louis, J.-F.

    1995-01-01

    A model of net primary production (NPP), decomposition, and nitrogen cycling in tundra ecosystems has been developed. The adjoint technique is used to study the sensitivity of the computed annual net CO2 flux to perturbation in initial conditions, climatic inputs, and model's main parameters describing current seasonal CO2 exchange in wet sedge tundra at Barrow, Alaska. The results show that net CO2 flux is most sensitive to parameters characterizing litter chemical composition and more sensitive to decomposition parameters than to NPP parameters. This underlines the fact that in nutrient-limited ecosystems, decomposition drives net CO2 exchange by controlling mineralization of main nutrients. The results also indicate that the short-term (1 year) response of wet sedge tundra to CO2-induced warming is a significant increase in CO2 emission, creating a positive feedback to atmosphreic CO2 accumulation. However, a cloudiness increase during the same year can severely alter this response and lead to either a slight decrease or a strong increase in emitted CO2, depending on its exact timing. These results demonstrate that the adjoint method is well suited to study systems encountering regime changes, as a single run of the adjoint model provides sensitivities of the net CO2 flux to perturbations in all parameters and variables at any time of the year. Moreover, it is shown that large errors due to the presence of thresholds can be avoided by first delimiting the range of applicability of the adjoint results.

  5. Natural CO2 accumulations in the western Williston Basin: A mineralogical analog for CO2 injection at the Weyburn site

    DOE PAGES

    Ryerson, F. J.; Lake, John; Whittaker, Steven; ...

    2013-01-17

    The Devonian carbonates of the Duperow Formation on the western flank of the Williston Basin in southwest Saskatchewan contain natural accumulations of CO2, and may have done so for as long as 50 million years. These carbonate sediments are characterized by a succession of carbonate cycles capped by anhydrite-rich evaporites that are thought to act as seals to fluid migration. The Weyburn CO2 injection site lies 400 km to the east in a series of Mississippian carbonates that were deposited in a similar depositional environment. That long-term isolation of natural CO2 can be accomplished within carbonate strata has motivated themore » investigation of the Duperow rocks as a potential natural analog for storage of anthropogenic CO2 in carbonate lithologies. For the Duperow strata to represent a legitimate analog for Midale injection and storage, the similarity in lithofacies, whole rock compositions, mineral compositions and porosity with the Midale Beds must be established. Here we compare lithofacies, whole rock compositions, mineralogy and mineral compositions from both locales. The major mineral phases at both locales are calcite, dolomite and anhydrite. In addition, accessory pyrite, fluorite, quartz and celestine (strontium sulfate) are also observed. Dawsonite, a potential CO2-trapping mineral, is not observed within the CO2-bearing horizons of the Duperow Formation, however. The distribution of porosity in the Midale Vuggy units is similar to that of the Duperow Formation, but the Marly units of the Midale have significantly higher porosity. The Duperow Formation is topped by the Dinesmore evaporite that is rich in anhydrite, and often contains authigenic K-feldspar. The chemistry of dolomite and calcite from the two localities also overlaps. Silicate minerals are in low abundance (<3%) within the analyzed Duperow samples, with quartz and K-feldspar the only silicates observed petrographically or in X-ray diffraction patterns. The Midale Beds contain

  6. Potential for the Use of Wireless Sensor Networks for Monitoring of CO2 Leakage Risks

    NASA Astrophysics Data System (ADS)

    Pawar, R.; Illangasekare, T. H.; Han, Q.; Jayasumana, A.

    2015-12-01

    Storage of supercritical CO2 in deep saline geologic formation is under study as a means to mitigate potential global climate change from green house gas loading to the atmosphere. Leakage of CO2 from these formations poses risk to the storage permanence goal of 99% of injected CO2 remaining sequestered from the atmosphere,. Leaked CO2 that migrates into overlying groundwater aquifers may cause changes in groundwater quality that pose risks to environmental and human health. For these reasons, technologies for monitoring, measuring and accounting of injected CO2 are necessary for permitting of CO2 sequestration projects under EPA's class VI CO2 injection well regulations. While the probability of leakage related to CO2 injection is thought to be small at characterized and permitted sites, it is still very important to protect the groundwater resources and develop methods that can efficiently and accurately detect CO2 leakage. Methods that have been proposed for leakage detection include remote sensing, soil gas monitoring, geophysical techniques, pressure monitoring, vegetation stress and eddy covariance measurements. We have demonstrated the use of wireless sensor networks (WSN) for monitoring of subsurface contaminant plumes. The adaptability of this technology for leakage monitoring of CO2 through geochemical changes in the shallow subsurface is explored. For this technology to be viable, it is necessary to identify geochemical indicators such as pH or electrical conductivity that have high potential for significant change in groundwater in the event of CO2 leakage. This talk presents a conceptual approach to use WSNs for CO2 leakage monitoring. Based on our past work on the use of WSN for subsurface monitoring, some of the challenges that need to be over come for this technology to be viable for leakage detection will be discussed.

  7. Plant adaptation or acclimation to rising CO2 ? Insight from first multigenerational RNA-Seq transcriptome.

    PubMed

    Watson-Lazowski, Alexander; Lin, Yunan; Miglietta, Franco; Edwards, Richard J; Chapman, Mark A; Taylor, Gail

    2016-11-01

    Atmospheric carbon dioxide (CO2 ) directly determines the rate of plant photosynthesis and indirectly effects plant productivity and fitness and may therefore act as a selective pressure driving evolution, but evidence to support this contention is sparse. Using Plantago lanceolata L. seed collected from a naturally high CO2 spring and adjacent ambient CO2 control site, we investigated multigenerational response to future, elevated atmospheric CO2 . Plants were grown in either ambient or elevated CO2 (700 μmol mol(-1) ), enabling for the first time, characterization of the functional and population genomics of plant acclimation and adaptation to elevated CO2 . This revealed that spring and control plants differed significantly in phenotypic plasticity for traits underpinning fitness including above-ground biomass, leaf size, epidermal cell size and number and stomatal density and index. Gene expression responses to elevated CO2 (acclimation) were modest [33-131 genes differentially expressed (DE)], whilst those between control and spring plants (adaptation) were considerably larger (689-853 DE genes). In contrast, population genomic analysis showed that genetic differentiation between spring and control plants was close to zero, with no fixed differences, suggesting that plants are adapted to their native CO2 environment at the level of gene expression. An unusual phenotype of increased stomatal index in spring but not control plants in elevated CO2 correlated with altered expression of stomatal patterning genes between spring and control plants for three loci (YODA, CDKB1;1 and SCRM2) and between ambient and elevated CO2 for four loci (ER, YODA, MYB88 and BCA1). We propose that the two positive regulators of stomatal number (SCRM2) and CDKB1;1 when upregulated act as key controllers of stomatal adaptation to elevated CO2 . Combined with significant transcriptome reprogramming of photosynthetic and dark respiration and enhanced growth in spring plants, we have

  8. Physiological and genetic control mechanisms for plant adaptation to high temperature and elevated CO2

    SciTech Connect

    Zeiger, Eduardo

    2001-02-01

    Acclimations of the stomatal response to CO2 were characterized. Stomata from the model plant used, Vicia faba, are very sensitive to ambient CO2 when grown in growth chambers as compared to stomata from green house grown leaves. The different CO2 sensitivities of growth chamber and green house grown guard cells was confirmed by reciprocal transfer experiments. Stomata acclimated to their new environment and acquired the CO2 sensitivity typical of that environment. A mechanism for CO2 sensing was also characterized. Results show that CO2 concentration alters the concentration of zeaxanthin in the guard cell chloroplast, thus modifying the light response of the guard cells. This mechanism accounts for the well characterized interactions of light and CO2 in the stomatal responses. The xanthophyll cycle in the stomata of the facultative CAM plant, Mesembryanthemum crystallinum, was characterized. In the C3 mode, zeaxanthin is formed in the light and stomata open. Upon induction of the CAM mode, zeaxanthin synthesis is blocked and stomata no longer respond to light. These results implicate the regulation of the xanthophyll cycle of guard cells in the CAM adaptation.

  9. Bioenergy from forestry and changes in atmospheric CO2: reconciling single stand and landscape level approaches.

    PubMed

    Cherubini, Francesco; Guest, Geoffrey; Strømman, Anders H

    2013-11-15

    Analyses of global warming impacts from forest bioenergy systems are usually conducted either at a single stand level or at a landscape level, yielding findings that are sometimes interpreted as contrasting. In this paper, we investigate and reconcile the scales at which environmental impact analyses of forest bioenergy systems are undertaken. Focusing on the changes caused in atmospheric CO2 concentration of forest bioenergy systems characterized by different initial states of the forest, we show the features of the analyses at different scales and depict the connections between them. Impacts on atmospheric CO2 concentration at a single stand level are computed through impulse response functions (IRF). Results at a landscape level are elaborated through direct application of IRFs to the emission profile, so to account for the fluxes from all the stands across time and space. Impacts from fossil CO2 emissions are used as a benchmark. At a landscape level, forest bioenergy causes an increase in atmospheric CO2 concentration for the first decades that is similar to the impact from fossil CO2, but then the dynamics clearly diverge because while the impact from fossil CO2 continues to rise that from bioenergy stabilizes at a certain level. These results perfectly align with those obtained at a single stand for which characterization factors have been developed. In the hypothetical case of a sudden cessation of emissions, the change caused in atmospheric CO2 concentration from biogenic CO2 emissions reverses within a couple of decades, while that caused by fossil CO2 emissions remains considerably higher for centuries. When counterfactual aspects like the additional sequestration that would have occurred in the forest if not harvested and the theoretical displacement of fossil CO2 are included in the analysis, results can widely differ, as the CO2 debt at a landscape level ranges from a few years to several centuries (depending on the underlying assumptions considered).

  10. Ultrasonic laboratory measurements of the seismic velocity changes due to CO2 injection

    NASA Astrophysics Data System (ADS)

    Park, K. G.; Choi, H.; Park, Y. C.; Hwang, S.

    2009-04-01

    Monitoring the behavior and movement of carbon dioxide (CO2) in the subsurface is a quite important in sequestration of CO2 in geological formation because such information provides a basis for demonstrating the safety of CO2 sequestration. Recent several applications in many commercial and pilot scale projects and researches show that 4D surface or borehole seismic methods are among the most promising techniques for this purpose. However, such information interpreted from the seismic velocity changes can be quite subjective and qualitative without petrophysical characterization for the effect of CO2 saturation on the seismic changes since seismic wave velocity depends on various factors and parameters like mineralogical composition, hydrogeological factors, in-situ conditions. In this respect, we have developed an ultrasonic laboratory measurement system and have carried out measurements for a porous sandstone sample to characterize the effects of CO2 injection to seismic velocity and amplitude. Measurements are done by ultrasonic piezoelectric transducer mounted on both ends of cylindrical core sample under various pressure, temperature, and saturation conditions. According to our fundamental experiments, injected CO2 introduces the decrease of seismic velocity and amplitude. We identified that the velocity decreases about 6% or more until fully saturated by CO2, but the attenuation of seismic amplitude is more drastically than the velocity decrease. We also identified that Vs/Vp or elastic modulus is more sensitive to CO2 saturation. We note that this means seismic amplitude and elastic modulus change can be an alternative target anomaly of seismic techniques in CO2 sequestration monitoring. Thus, we expect that we can estimate more quantitative petrophysical relationships between the changes of seismic attributes and CO2 concentration, which can provide basic relation for the quantitative assessment of CO2 sequestration by further researches.

  11. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    NASA Astrophysics Data System (ADS)

    Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

    2012-10-01

    Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is challenging, but essential in order to utilize CO2 measurements in an atmospheric inverse framework to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration, during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town-Energy Balance (TEB) urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs) surface scheme, allowing a full interaction of CO2 between the surface and the atmosphere. Statistical scores show a good representation of the Urban Heat Island (UHI) and urban-rural contrasts. Boundary layer heights (BLH) at urban, sub-urban and rural sites are well captured, especially the onset time of the BLH increase and its growth rate in the morning, that are essential for tall tower CO2 observatories. Only nocturnal BLH at sub-urban sites are slightly underestimated a few nights, with a bias less than 50 m. At Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the Atmospheric Boundary Layer (ABL) growth reaches the measurement height. The timing of the CO2 cycle is well captured by the model, with only small biases on CO2 concentrations, mainly linked to the misrepresentation of anthropogenic emissions, as the Eiffel site is at the heart of trafic emission sources. At sub-urban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a very strong spatio-temporal variability. The CO2 cycle at these sites is generally well reproduced by the model, even if some biases on the nocturnal maxima appear in the Paris plume parly due to small errors on the vertical transport, or in

  12. CO2 adsorption isotherm on clay minerals and the CO2 accessibility into the clay interlayer

    NASA Astrophysics Data System (ADS)

    Gensterblum, Yves; Bertier, Pieter; Busch, Andreas; Rother, Gernot; Krooß, Bernhard

    2013-04-01

    Large-scale CO2 storage in porous rock formations at 1-3 km depth is seen as a global warming mitigation strategy. In this process, CO2 is separated from the flue gas of coal or gas power plants, compressed, and pumped into porous subsurface reservoirs with overlying caprocks (seals). Good seals are mechanically and chemically stable caprocks with low porosity and permeability. They prevent leakage of buoyant CO2 from the reservoir. Caprocks are generally comprised of thick layers of shale, and thus mainly consist of clay minerals. These clays can be affected by CO2-induced processes, such as swelling or dissolution. The interactions of CO2 with clay minerals in shales are at present poorly understood. Sorption measurements in combination scattering techniques could provide fundamental insight into the mechanisms governing CO2-clay interaction. Volumetric sorption techniques have assessed the sorption of supercritical CO2 onto coal (Gensterblum et al., 2010; Gensterblum et al., 2009), porous silica (Rother et al., 2012a) and clays as a means of exploring the potential of large-scale storage of anthropogenic CO2 in geological reservoirs (Busch et al., 2008). On different clay minerals and shales, positive values of excess sorption were measured at gas pressures up to 6 MPa, where the interfacial fluid is assumed to be denser than the bulk fluid. However, zero and negative values were obtained at higher densities, which suggests the adsorbed fluid becomes equal to and eventually less dense than the corresponding bulk fluid, or that the clay minerals expand on CO2 charging. Using a combination of neutron diffraction and excess sorption measurements, we recently deduced the interlayer density of scCO2 in Na-montmorillonite clay in its single-layer hydration state (Rother et al., 2012b), and confirmed its low density, as well as the expansion of the basal spacings. We performed neutron diffraction experiments at the FRMII diffractometer on smectite, kaolinite and illite

  13. Temporal constraints on hydrate-controlled methane seepage off Svalbard.

    PubMed

    Berndt, C; Feseker, T; Treude, T; Krastel, S; Liebetrau, V; Niemann, H; Bertics, V J; Dumke, I; Dünnbier, K; Ferré, B; Graves, C; Gross, F; Hissmann, K; Hühnerbach, V; Krause, S; Lieser, K; Schauer, J; Steinle, L

    2014-01-17

    Methane hydrate is an icelike substance that is stable at high pressure and low temperature in continental margin sediments. Since the discovery of a large number of gas flares at the landward termination of the gas hydrate stability zone off Svalbard, there has been concern that warming bottom waters have started to dissociate large amounts of gas hydrate and that the resulting methane release may possibly accelerate global warming. Here, we corroborate that hydrates play a role in the observed seepage of gas, but we present evidence that seepage off Svalbard has been ongoing for at least 3000 years and that seasonal fluctuations of 1° to 2°C in the bottom-water temperature cause periodic gas hydrate formation and dissociation, which focus seepage at the observed sites.

  14. Effect of vegetation type on throughfall deposition and seepage flux.

    PubMed

    De Schrijver, A; Staelens, J; Wuyts, K; Van Hoydonck, G; Janssen, N; Mertens, J; Gielis, L; Geudens, G; Augusto, L; Verheyen, K

    2008-05-01

    This paper compares different vegetation types (coniferous and deciduous forest, grassed and pure heathland) in terms of input (throughfall deposition) and output (seepage flux) in a region with intermediate nitrogen load (+/-20kg Nha(-1)y(-1) via bulk precipitation) in comparable conditions in north Belgium. Coniferous forest (two plots Pinus sylvestris and two plots Pinus nigra) received significantly higher nitrogen and sulphur throughfall deposition than deciduous forest and heathland. Grassed and pure heathland had significantly highest throughfall quantities of Ca(2+) and Mg(2+), respectively. The observed differences in throughfall deposition between the different vegetation types were not univocally reflected in the ion seepage flux. Considerable seepage fluxes of NO(3)(-), SO(4)(2-), Ca(2+) and Al(III) were only found under the P. nigra plots. We discuss our hypothesis that the P. nigra forests already evolved to a situation of N saturation, while the other vegetation types did not.

  15. Water quality effects of seepage from earthen dams