Science.gov

Sample records for coal combustion process

  1. Application of polymer membrane technology in coal combustion processes

    SciTech Connect

    Kaldis, S.P.; Skodras, G.; Grammelis, P.; Sakellaropoulos, G.P.

    2007-03-15

    The energy efficiency and the environmental consequences of typical coal upgrading processes, such as combustion, depend to a large extent on the degree of gas separation, recovery, and recycle. Among the available methods used in chemical industry for a variety of gas separation tasks, the technology of polymer membranes offers several advantages such as low size, simplicity of operation and maintenance, compatibility, and use with a diversity of fuel sources. To examine the impact of membrane separation on coal upgrading processes, the Aspen Plus simulation software was used, in combination with developed membrane mathematical models. Energy analysis in coal combustion processes, where the main scope is CO{sub 2} removal, showed that very promising results can be attained. It is estimated that 95% of the emitted CO{sub 2} can be captured with a moderately low energy penalty (10%). This penalty can be further decreased if higher selectivity and/or permeability polymers can be developed.

  2. Coal Combustion Science

    SciTech Connect

    Hardesty, D.R.; Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. )

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  3. Numerical simulation of the coal combustion process initiated by a plasma source

    NASA Astrophysics Data System (ADS)

    Askarova, A. S.; Messerle, V. E.; Ustimenko, A. B.; Bolegenova, S. A.; Maksimov, V. Yu.

    2014-12-01

    Numerical experiments on the torch combustion of the coal dust prepared by a plasma-thermochemical treatment for combustion have been done using the method of three-dimensional simulation. It is shown that the plasma preparation of coal for combustion enables one to optimize the process, improve the conditions for inflammation and combustion and minimize the emissions of harmful substances.

  4. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  5. Monitoring temperatures in coal conversion and combustion processes via ultrasound

    NASA Astrophysics Data System (ADS)

    Gopalsami, N.; Raptis, A. C.; Mulcahey, T. P.

    1980-02-01

    The state of the art of instrumentation for monitoring temperatures in coal conversion and combustion systems is examined. The instrumentation types studied include thermocouples, radiation pyrometers, and acoustical thermometers. The capabilities and limitations of each type are reviewed. A feasibility study of the ultrasonic thermometry is described. A mathematical model of a pulse-echo ultrasonic temperature measurement system is developed using linear system theory. The mathematical model lends itself to the adaptation of generalized correlation techniques for the estimation of propagation delays. Computer simulations are made to test the efficacy of the signal processing techniques for noise-free as well as noisy signals. Based on the theoretical study, acoustic techniques to measure temperature in reactors and combustors are feasible.

  6. Laser diagnostics of mineral matter and combustion processes in coal

    SciTech Connect

    Venkateswarlu, P.; George, M.C.; Sekhar, P.C.; Subbarao, V.

    1989-01-01

    This is the third report on this project. During the period covered by the first two reports (October 1, 1987 through August 30, 1988) a sample of low sulfur powdered coal was heated under vacuum from 25 to 1000{degrees}C at a heating rate of 5{degrees}C per minute. The vapors generated were analyzed by a Balzer Quadrupole Mass Spectrometer model QMG 511. The analysis showed that the major constituents of the vapors are aliphatic hydrocarbons. A second set of experiments were carried out to determine the mineral constituents in ash obtained by heating coal in a porcelain crucible at 400--500{degrees}C in a muffle furnace until all the coal was oxidized. Model 3030 Perkin Elmer Atomic Absorption Spectrophotometer was used with appropriate hollow cathode lamps. A dozen elements were identified. Al, Na, K and Fe were the most prominent. During this period we have made an extensive series of measurements on laser induced combustion of coal pellets made from coal powder. C{sub 2}, CN, CO, Na and K were identified from the spectra. We have also fabricated a burner for the study of coal combustion using laser spectroscopic techniques. 1 ref., 4 figs.

  7. Evolution of Submicrometer Organic Aerosols during a Complete Residential Coal Combustion Process.

    PubMed

    Zhou, Wei; Jiang, Jingkun; Duan, Lei; Hao, Jiming

    2016-07-19

    In the absence of particulate matter (PM) control devices, residential coal combustion contributes significantly to ambient PM pollution. Characterizing PM emissions from residential coal combustion with high time resolution is beneficial for developing control policies and evaluating the environmental impact of PM. This study reports the evolution of submicrometer organic aerosols (OA) during a complete residential coal combustion process, that is, from fire start to fire extinction. Three commonly used coal types (bituminous, anthracite, and semicoke coals) were evaluated in a typical residential stove in China. For all three types of coal, the OA emission exhibited distinct characteristics in the four stages, that is, ignition, fierce combustion, relatively stable combustion, and ember combustion. OA emissions during the ignition stage accounted for 58.2-85.4% of the total OA emission of a complete combustion process. The OA concentration decreased rapidly during the fierce combustion stage and remained low during the relatively stable combustion stage. During these two stages, a significant ion peak of m/z 73 from organic acids were observed. The degree of oxidation of the OA increased from the first stage to the last stage. Implications for ambient OA source-apportionment and residential PM emission characterization and control are discussed. PMID:27298095

  8. Coal combustion products

    USGS Publications Warehouse

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  9. Coal combustion research

    SciTech Connect

    Daw, C.S.

    1996-06-01

    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  10. Digital image processing applications in the ignition and combustion of char/coal particles

    SciTech Connect

    Annamalai, K.; Kharbat, E.; Goplakrishnan, C.

    1992-12-01

    Digital image processing, is employed in this remarch study in order to visually investigate the ignition and combustion characteristics of isolated char/coal particles as well as the effect of interactivecombustion in two-particle char/coal arrays. Preliminary experiments are conducted on miniature isolated candles as well as two-candle arrays.

  11. Coal combustion: Effect of process conditions on char reactivity

    SciTech Connect

    Zygourakis, K.

    1991-01-01

    The project will quantify the effect of the following pyrolysis conditions on the macropore structure and on the subsequent reactivity of chars: (a) pyrolysis heating rate; (b) final heat treatment temperature (HTT); (c) duration of heat treatment at HTT (or soak time); (d) pyrolysis atmosphere (N{sub 2} or O{sub 2}/N{sub 2} mixtures); (e) coal particle size (100 {endash} 1000 {mu}m in diameter); (f) sulfur-capturing additives (limestone); and (g) coal rank. Pyrolysis experiments will be carried out for three coals from the Argonne collection: (1) a high-volatile bituminous coal with high ash content (Illinois {number sign}6), (2) a bituminous coal with low ash content (Utah Blind Canyon) and (3) a lower rank subbituminous coal (Wyodak-Anderson seam).

  12. Environmentally conscious coal combustion

    SciTech Connect

    Hickmott, D.D.; Brown, L.F.; Currier, R.P.

    1997-08-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to evaluate the environmental impacts of home-scale coal combustion on the Navajo Reservation and develop strategies to reduce adverse health effects associated with home-scale coal combustion. Principal accomplishments of this project were: (1) determination of the metal and gaseous emissions of a representative stove on the Navajo Reservation; (2) recognition of cyclic gaseous emissions in combustion in home-scale combustors; (3) `back of the envelope` calculation that home-scale coal combustion may impact Navajo health; and (4) identification that improved coal stoves require the ability to burn diverse feedstocks (coal, wood, biomass). Ultimately the results of Navajo home-scale coal combustion studies will be extended to the Developing World, particularly China, where a significant number (> 150 million) of households continue to heat their homes with low-grade coal.

  13. Coal combustion system

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

    1988-01-01

    In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

  14. Coal combustion: Effect of process conditions on char reactivity. Final technical report, September 1, 1991--May 31, 1995

    SciTech Connect

    Zygourakis, K.

    1996-02-01

    Coal utilization involves two major stages: coal pyrolysis and char combustion. Figure 1.1 summarizes the steps of these processes. During the pyrolysis stage, heated particles from plastic coals soften, swell and release their volatiles before resolidifying again. During the combustion or gasification stage, char particles may ignite and fragment as the carbon is consumed leaving behind a solid ash residue. Process conditions such as pyrolysis heating rate, heat treatment temperature, pyrolysis atmosphere, and particle size are shown to chemically and physically affect the coal during pyrolysis and the resulting char. Consequently, these pyrolysis conditions as well as the combustion conditions such as the oxygen concentration and combustion temperature affect the char reactivity and ignition phenomena during the combustion stage. Better understanding of the fundamental mechanisms of coal pyrolysis and char combustion is needed to achieve greater and more efficient utilization of coal. Furthermore, this knowledge also contributes to the development of more accurate models that describe the transient processes involved in coal combustion. The project objectives were to investigate the effect of pyrolysis conditions on the macropore structure and subsequent reactivity of chars.

  15. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-09-03

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation's Phase III development contract DE-AC22-91PC91161 for a Coal-Fired Combustion System for Industrial Process Heating Applications'' is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelling and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, approval of Vortec's Environmental Assessment (EA) required under the National Environmental Policy Act (NEPA) was approved. The EA approval cycle took approximately 9 months. The preliminary test program which was being held in abeyance pending approval of the EA was initiated. Six preliminary test runs were successfully competed during the period. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the preliminary tests were completed.

  16. Coal combustion ash haulback

    SciTech Connect

    Gray, R.E.; Gray, T.A.

    1998-12-31

    Coal mining disturbs large tracts of land which must be reclaimed. Unfortunately, iron sulfides which are common in most coals and the adjacent strata weather, forming acid mine drainage (AMD) which degrades surface and ground water. Burning of coal produces combustion by products, most of which are placed in ponds or landfills. Suitable disposal areas are difficult to find and permit, especially in urban areas. This has led to ash haulback--where the waste generated during coal burning is hauled back to a mine for disposal. The potential advantages of coal combustion ash haulback are: Disposal occurs in a disturbed area (mine) rather than disturb additional land near the power plant; The same vehicles used to haul coal from the mine can be used to return the ash to the mine; Ash, if alkaline, may provide neutralization of acidic water or mine overburden commonly found at coal mines; and Low permeability ash could reduce ground water flow through the mine backfill, thus reducing leaching of acid forming constituents or metals. Placement of ash in surface mines provides an efficient, cost-effective method of disposal while at the same time contributing to reclamation of the mine. Wise natural resource management suggests a reasonable approach to disposal of coal ash is to return it to its original location--the mine.

  17. The development of a coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-07-16

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation's Coal-Fired Combustion System for Industrial Process Heating Applications has been selected for Phase III development under contract DE-AC22-91PC91161. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting, recycling, and refining processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase HI research effort is being focused on the development of a process heater system to be used for producing glass frits and wool fiber from boiler and incinerator ashes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The economic evaluation of commercial scale CMS processes has begun. In order to accurately estimate the cost of the primary process vessels, preliminary designs for 25, 50, and 100 ton/day systems have been started under Task 1. This data will serve as input data for life cycle cost analysis performed as part of techno-economic evaluations. The economic evaluations of commercial CMS systems will be an integral part of the commercialization plan.

  18. Combustion process and nitrogen oxides emission of Shenmu coal added with sodium acetate

    SciTech Connect

    Yang Weijuan; Zhou Junhu; Liu Maosheng; Zhou Zhijun; Liu Jianzhong; Cen Kefa

    2007-09-15

    Shenmu bituminous coal with 4% sodium acetate added was used to investigate the characteristics of combustion and nitrogen oxide (NOx) release in a fixed bed reactor heated by a tube furnace. The composition of the flue gas was analyzed to investigate the effects of sodium acetate on the combustion process and NOx emission. The experiments were carried out in a partial reductive atmosphere and a strong oxidative atmosphere. The O{sub 2} valley value in the partial reductive atmosphere was reduced by the added sodium acetate. Sodium acetate accelerated the combustion and shortened the combustion process. The experimental results showed that the emissions of NO, NO{sub 2}, and N{sub 2}O were affected by the reacting atmosphere and the combustion temperature. In the strong oxidative atmosphere, sodium acetate resulted in a slight NOx reduction. In the partial reductive atmosphere, sodium acetate reduced both the peak value of NO concentration and the total NO emission significantly. An over 30% NOx reduction efficiency was achieved at 900{sup o}C in the partial reductive atmosphere, which decreased with the increase in temperature. Sodium acetate was decomposed into hydrocarbon radicals and sodium hydroxide, which can both reduce NOx emissions due to their special reactions with the nitrogen component. 17 refs., 11 figs., 2 tabs.

  19. Use of coal combustion byproducts in biosolids stabilization: The N-Viro process

    SciTech Connect

    Logan, T.J.

    1999-07-01

    The patented N-Viro process for alkaline stabilization of municipal sewage sludge (biosolids) is a 10-year old technology that utilizes a variety of alkaline byproducts. These include cement kiln dust, lime kiln dust, flue gas desulfurization (FGD) byproducts, fluidized-bed coal combustion ashes, and Class C and F fly ashes. The alkaline byproducts are used in the N-Viro process to raise pH ({gt}12), produce heat (52--62 C) and increase solids content of the biosolids (50--65% solids). Typical operations use a blend of reactive (produces heat) and non-reactive byproducts in the process, with selection of materials being driven by local availability and cost. There are 38 N-Viro facilities in the US, Canada, Australia, the UK, and Belgium, with the majority in the eastern US. Of these, 15 use coal combustion byproducts (CCBs) on a regular basis. These facilities process more than 250,000 dry tons of biosolids a year, utilize about 125,000 tons of CCBs annually, and produce more than 1,000,000 tons of the resulting product, N-Viro Soil, per year. The use of CCBs is expected to increase dramatically in the next few years. N-Viro Soil, regulated by US EPA as an EQ biosolids, is marketed and distributed as agricultural lime, fertilizer, and as a soil substitute for reclamation and horticulture. This paper discusses the properties of alkaline materials that are required in the N-Viro process, compares those properties to that of various CCBs, and discusses the potential benefit to coal-burning power plants of recycling CCBs to beneficial uses rather than disposal.

  20. Kinetics of coal combustion: Eighth quarterly report

    SciTech Connect

    Gat, N.; Petach, M.; Gavalas, G.R.; Flagan, R.C.

    1987-02-01

    The investigation of fundamentals of coal combustion kinetics addresses several topics of major importance relative to improved understanding of pulverized coal combustion and includes both homogeneous and heterogeneous reactions. The principal topics include: (1) combustion of volatiles, and (2) heterogeneous combustion of coal/char. Research activities include small-scale experimentation, interpretation of experimental results in terms of mechanistic understanding, and the development of validation of kinetic models of fundamental processes. The project is divided into three major tasks, the details of which are provided. 20 figs., 1 tab.

  1. Analysis of Combustion Process of Sewage Sludge in Reference to Coals and Biomass

    NASA Astrophysics Data System (ADS)

    Środa, Katarzyna; Kijo-Kleczkowska, Agnieszka

    2016-06-01

    Production of sewage sludge is an inseparable part of the treatment process. The chemical and sanitary composition of sewage sludge flowing into the treatment plant is a very important factor determining the further use of the final product obtained in these plants. The sewage sludge is characterized by heterogeneity and multi-components properties, because they have characteristics of the classical and fertilizer wastes and energetic fuels. The thermal utilization of sewage sludge is necessary due to the unfavorable sanitary characteristics and the addition of the industrial sewage. This method ensures use of sewage sludge energy and return of expenditure incurred for the treatment of these wastes and their disposal. Sewage sludge should be analyzed in relation to conventional fuels (coals and biomass). They must comply with the applicable requirements, for example by an appropriate degree of dehydration, which guarantee the stable and efficient combustion. This paper takes the issue of the combustion process of the different sewage sludge and their comparison of the coal and biomass fuels.

  2. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. ne primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order toevaluate its potential marketability. During the current reporting period, three preliminary coal-fired tests were successfully completed. These tests used industrial boiler flyash, sewer sludge ash, and waste glass collet as feedstocks. The coal-fired ash vitrification tests are considered near term potential commercial applications of the CMS technology. The waste glass cullet provided necessary dam on the effect of coal firing with respect to vitrified product oxidation state. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the proof-of-concept tests are continuing. The economic evaluation of commercial scale CMS processes is continuing. Preliminary designs for 15, 25, 100 and 400 ton/day systems are in progress. This dam will serve as input data to the life cycle cost analysis which will be-an integral part of the CMS commercialization plan.

  3. Kinetics of coal combustion: Seventh quarterly report

    SciTech Connect

    Gat, N.; Petach, M.; Gavalas, G.R.; Flagan, R.C.; Essenhigh, R.H.

    1986-10-01

    The objective of this investigation is to develop an improved comprehensive understanding of the kinetics of coal combustion relevant to suspension firing of powdered coal. The program is being carreid out by investigators from several institutions: TRW (prime contractor), Ohio State University (OSU), and California Institute of Technology (CIT), (both subcontractors). The investigation of fundamentals of coal combustion kinetics addresses several topics of major importance relative to improved understanding of pulverized coal combustion and includes both homogeneous and heterogeneous reactions. The principal topics include: (1) combustion of volatiles; and (2) heterogeneous combustion of coal/char. Research activities include small-scale experimentation, interpretation of experimental results in terms of mechanistic understanding, and the development of validation of kinetic models of fundamental processes. 9 refs., 20 figs., 4 tabs.

  4. Metal attenuation processes in a landfill containing coal combustion waste: Implications for remediation

    SciTech Connect

    Barton, Christopher; Paddock, Lindy; Romanek, Christopher; Maharaj, Sally; Seaman, John

    2005-03-01

    Barton, Christopher, L. Paddock, Cromanek, S. Maharaj, and J. Seaman. 2005. Metal attenuation processes in a landfill containing coal combustion waste: Implications for remediation. Env. Geosci. 12(1): 45-55. Abstract - The 488-D Ash Basin (488-DAB) is an unlined, earthen landfill containing approximately 1 million t of dry ash and coal reject material at the U.S. Department of Energy's Savannah River Site, South Carolina. The pyritic nature of the coal rejects has resulted in the formation of acidic drainage, which has contributed to groundwater deterioration and threatened biota in adjacent wetlands. Establishment of a vegetation cover to both deplete oxygen through biological means and optimize evapotranspiration has been established as a remedial alternative for reducing acidic drainage generation in the 488-DAB. To determine the potential benefits of a cover, a series of characterization studies were conducted prior to field deployment to gain a better understanding of the metal attenuation processes and to use water quality and substrate data to evaluate the potential effectiveness of this remedial approach. The characterization study indicated that metal attenuation was primarily controlled by fluctuating redox and pH gradients associated with alternating saturated and unsaturated conditions in the basin. Based on this information, a vegetative cover could reduce the production of acid leachate over time, pending that oxygen transport to the subsurface is limited.

  5. A coal-fired combustion system for industrial processing heating applications. Quarterly technical progress report, January 1995--March 1995

    SciTech Connect

    1995-04-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The test program consisted of one test run, with a duration of 100 hours at a nominal feed rate of 1000 lbs/hr. Throughout the test, the CMS was fired with coal and a coal by-product (i.e. coal-fired boiler fly ash) as the primary fuels. Natural gas was used as an auxiliary fuel as necessary to provide process trim. The feedstock consisted of a coal-fired utility boiler fly ash and dolomite and produced a stable, fully-reacted vitrified product. The fly ash, supplied by PENELEC, contained between 6 and 12% by weight of carbon because of the low NOx burners on the PENELEC boilers. Therefore, a substantial portion of the required thermal input came from the fly ash.

  6. Evaluation of a sequential extraction process used for determining mercury binding mechanisms to coal combustion byproducts

    SciTech Connect

    James D. Noel; Pratim Biswas; Daniel E. Giammar

    2007-07-15

    This study evaluated the selectivity and effectiveness of a sequential extraction process used to determine mercury binding mechanisms to various materials that are present in coal combustion byproducts. A six-step sequential extraction process was applied to laboratory-synthesized materials with known mercury concentrations and binding mechanisms. These materials were calcite, hematite, goethite, and titanium dioxide. Fly ash from a full-scale coal-fired power plant was also investigated. The concentrations of mercury were measured using inductively coupled plasma (ICP) mass spectrometry, whereas the major elements were measured by ICP atomic emission spectrometry. The materials were characterized by X-ray powder diffraction and scanning electron microscopy with energy dispersive spectroscopy. The sequential extraction procedure provided information about the solid phases with which mercury was associated in the solid sample. The procedure effectively extracted mercury from the target phases. The procedure was generally selective in extracting mercury. However, some steps in the procedure extracted mercury from nontarget phases, and others resulted in mercury redistribution. Iron from hematite and goethite was only leached in the reducible and residual extraction steps. Some mercury associated with goethite was extracted in the ion exchangeable step, whereas mercury associated with hematite was extracted almost entirely in the residual step. Calcium in calcite and mercury associated with calcite were primarily removed in the acidsoluble extraction step. Titanium in titanium dioxide and mercury adsorbed onto titanium dioxide were extracted almost entirely in the residual step. 42 refs., 13 figs., 2 tabs.

  7. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1994--September 1994

    SciTech Connect

    1994-12-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability.

  8. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, October 1993--December 1993

    SciTech Connect

    1994-01-30

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the major effort was completing the system modification installation designs, completing the TSCA ash testing, and conducting additional industry funded testing. Final detailed installation designs for the integrated test system configuration are being completed.

  9. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1993-01-29

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent relining the separator/reservoir and the cyclone melter. The relinings were completed, the cyclonemelter was reinstalled, and the test system was returned to operational status. The wet ESP was delivered and placed on its foundation. The focus during the upcoming months will be completing the integration ofthe wet ESP and conducting the first industrial proof-of-concept test. The other system modifications are well underway with the designs of the recuperator installation and the batch/coal feed system progressing smoothly. The program is still slightly behind the original schedule but it is anticipated that it will be back on schedule by the end of the year. The commercialization planning is continuing with the identification of seven potential near-term commercial demonstration opportunities.

  10. Coal char fragmentation during pulverized coal combustion

    SciTech Connect

    Baxter, L.L.

    1995-07-01

    A series of investigations of coal and char fragmentation during pulverized coal combustion is reported for a suite of coals ranging in rank from lignite to low-volatile (lv) bituminous coal under combustion conditions similar to those found in commercial-scale boilers. Experimental measurements are described that utilize identical particle sizing characteristics to determine initial and final size distributions. Mechanistic interpretation of the data suggest that coal fragmentation is an insignificant event and that char fragmentation is controlled by char structure. Chars forming cenospheres fragment more extensively than solid chars. Among the chars that fragment, large particles produce more fine material than small particles. In all cases, coal and char fragmentation are seen to be sufficiently minor as to be relatively insignificant factors influencing fly ash size distribution, particle loading, and char burnout.

  11. Coal slurry combustion and technology. Volume 2

    SciTech Connect

    Not Available

    1983-01-01

    Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

  12. UNDERGROUNG PLACEMENT OF COAL PROCESSING WASTE AND COAL COMBUSTION BY-PRODUCTS BASED PASTE BACKFILL FOR ENHANCED MINING ECONOMICS

    SciTech Connect

    Y.P. Chugh; D. Biswas; D. Deb

    2002-06-01

    This project has successfully demonstrated that the extraction ratio in a room-and-pillar panel at an Illinois mine can be increased from the current value of approximately 56% to about 64%, with backfilling done from the surface upon completion of all mining activities. This was achieved without significant ground control problems due to the increased extraction ratio. The mined-out areas were backfilled from the surface with gob, coal combustion by-products (CCBs), and fine coal processing waste (FCPW)-based paste backfill containing 65%-70% solids to minimize short-term and long-term surface deformations risk. This concept has the potential to increase mine productivity, reduce mining costs, manage large volumes of CCBs beneficially, and improve the miner's health, safety, and environment. Two injection holes were drilled over the demonstration panel to inject the paste backfill. Backfilling was started on August 11, 1999 through the first borehole. About 9,293 tons of paste backfill were injected through this borehole with a maximum flow distance of 300-ft underground. On September 27, 2000, backfilling operation was resumed through the second borehole with a mixture of F ash and FBC ash. A high-speed auger mixer (new technology) was used to mix solids with water. About 6,000 tons of paste backfill were injected underground through this hole. Underground backfilling using the ''Groutnet'' flow model was simulated. Studies indicate that grout flow over 300-foot distance is possible. Approximately 13,000 tons of grout may be pumped through a single hole. The effect of backfilling on the stability of the mine workings was analyzed using SIUPANEL.3D computer program and further verified using finite element analysis techniques. Stiffness of the backfill mix is most critical for enhancing the stability of mine workings. Mine openings do not have to be completely backfilled to enhance their stability. Backfill height of about 50% of the seam height is adequate to

  13. Monitoring temperatures in coal conversion and combustion processes via ultrasound. [Ultrasonic thermometry proposal

    SciTech Connect

    Gopalsami, N.; Raptis, A. C.; Mulcahey, T. P.

    1980-02-01

    A study of the state-of-the-art of instrumentation for monitoring temperatures in coal conversion and combustion systems has been carried out. The instrumentation types studied include Thermocouples, Radiation Pyrometers, and Acoustical Thermometers. The capabilities and limitations of each type are reviewed. The study determined that ultrasonic thermometry has the potential of providing viable instrumentation. Consequently, a feasibility study of the ultrasonic thermometry was undertaken. A mathematical model of a pulse-echo ultrasonic temperature measurement system is developed using linear system theory. The mathematical model lends itself to the adaptation of generalized correlation techniques for the estimation of propagation delays. Computer simulations are made to test the efficacy of the signal processing techniques for noise-free as well as noisy signals. Based on the theoretical study, acoustic techniques to measure temperature in reactors and combustors are feasible. To experimentally verify the technique it is needed (a) to test the available sensor materials at high temperatures under erosive and corrosive conditions and (b) upon the selection of the appropriate sensor material to validate the proposed signal processing technique. The base for the applicability of this technique will be the frequency of operation, which will determine the length of the sensor and the noise background at the frequency of interest. It is, however, believed that the proposed technique will provide reliable estimates under the noise background.

  14. Kinetics of coal combustion: Part 1, Project description and summary

    SciTech Connect

    Gat, N. )

    1988-12-01

    The investigation of the fundamentals of coal combustion kinetics addressed several topics of major importance relative to improved understanding of pulverized coal combustion and included both homogeneous and heterogeneous reactions. The principal topics included are: (1) combustion of volatiles, and (2) heterogeneous combustion of coal/char. Research activities included small-scale experimentation, interpretation of experimental results in terms of mechanistic understanding, and the development and validation of kinetic models of fundamental processes.

  15. Catalyzing the Combustion of Coal

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; Dokko, W.

    1982-01-01

    Reaction rate of coal in air can be increased by contacting or coating coal with compound such as calcium acetate. The enhanced reaction rate generates more heat, reducing furnace size. Increase in combustion rate is about 26 percent, and internal pollutants in powerplant are reduced.

  16. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, October 1994--December 1994

    SciTech Connect

    1995-03-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the major effort was concentrated on conducting the 100 hour demonstration test. The test was successfully conducted from September 12th through the 16th. The test program consisted of one test run, with a duration of 100 hours at a nominal feed rate of 1000 lbs/hr. Throughout the test, the CMS was fired with coal and a coal by-product (i.e. coal-fired boiler flyash) as the primary fuels. Natural gas was used as an auxiliary fuel as necessary to provide process trim. The feedstock consisted of a coal-fired utility boiler flyash and dolomite and produced a stable, fully-reacted vitrified product. The fly ash, supplied by PENELEC, contained between 6 and 12% by weight of carbon because of the low NO{sub x} burners on the PENELEC boilers.

  17. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1992-01-01

    Ignition of the high volatile isolated coal particles in vitiated environment seems to occur heterogeneously at the leading edge of the particle. Volatiles are observed to be ejected upward as jets in the direction of the convective flow but only after heterogeneous ignition. The volatiles burn in the gas phase homogeneously and form a wake flame; a black inner zone (unburned volatile) is formed (see Fig.A.3 for many common characteristics of isolated flames).Intermittent volatile ignition and combustion are observed to occur during the combustion process for a few of the isolated particle combustion experiments on high volatile non-swelling coal. The medium volatile coal particles ignite faster than the high volatile coal; but the intermittent ignition is not observed. The low volatile isolated coal particles combust in shorter time. The isolated char particles ignite at the surface of the particle heterogeneously with little volatile ejected, yet are not sufficient to form a volatile flame, resulting in a subsequent heterogeneous combustion. A group flame is formed for the two-particle arrays at closer interparticle spacing (Fig.A.4). Also, intermittent ignition does not occur for the high volatile particles when the two particles are at farther distances which suggests that radiation interaction between the particles might be occurring. However this conclusion is purely speculative. The char arrays experience heterogeneous ignition at the leading edge; combustion proceeds heterogeneously.

  18. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1992--June 1992

    SciTech Connect

    Not Available

    1992-09-03

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a ``Coal-Fired Combustion System for Industrial Process Heating Applications`` is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelling and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, approval of Vortec`s Environmental Assessment (EA) required under the National Environmental Policy Act (NEPA) was approved. The EA approval cycle took approximately 9 months. The preliminary test program which was being held in abeyance pending approval of the EA was initiated. Six preliminary test runs were successfully competed during the period. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the preliminary tests were completed.

  19. Evaluation of a sequential extraction process used for determining mercury binding mechanisms to coal combustion byproducts.

    PubMed

    Noel, James D; Biswas, Pratim; Giammar, Daniel E

    2007-07-01

    Leaching of mercury from coal combustion byproducts is a concern because of the toxicity of mercury. Leachability of mercury can be assessed by using sequential extraction procedures. Sequential extraction procedures are commonly used to determine the speciation and mobility of trace metals in solid samples and are designed to differentiate among metals bound by different mechanisms and to different solid phases. This study evaluated the selectivity and effectiveness of a sequential extraction process used to determine mercury binding mechanisms to various materials. A six-step sequential extraction process was applied to laboratory-synthesized materials with known mercury concentrations and binding mechanisms. These materials were calcite, hematite, goethite, and titanium dioxide. Fly ash from a full-scale power plant was also investigated. The concentrations of mercury were measured using inductively coupled plasma (ICP) mass spectrometry, whereas the major elements were measured by ICP atomic emission spectrometry. The materials were characterized by X-ray powder diffraction and scanning electron microscopy with energy dispersive spectroscopy. The sequential extraction procedure provided information about the solid phases with which mercury was associated in the solid sample. The procedure effectively extracted mercury from the target phases. The procedure was generally selective in extracting mercury. However, some steps in the procedure extracted mercury from nontarget phases, and others resulted in mercury redistribution. Iron from hematite and goethite was only leached in the reducible and residual extraction steps. Some mercury associated with goethite was extracted in the ion exchangeable step, whereas mercury associated with hematite was extracted almost entirely in the residual step. Calcium in calcite and mercury associated with calcite were primarily removed in the acid-soluble extraction step. Titanium in titanium dioxide and mercury adsorbed onto

  20. Mineral impurities in coal combustion

    SciTech Connect

    Raask, E.

    1985-01-01

    This article discusses the many and varied problems associated with coal combustion and suggests remedial measures to assist in producing electrical energy from coal more efficiently. Contents include: influence of coal mineral matter on boiler design; mineral impurities in coal; quality of coal utilized in power stations; coal grinding, abrasive fuel minerals and plant wear; particulates silicate minerals in boiler flame; reactions of nonsilicate impurities in coal flame; creation, capture and coalescence of particulate ash in boiler flame; slag viscosity; sintering, fusion and slagging propensities of coal ashes, adhesion of ash deposit on boiler tubes and refractory materials; deposition mechanisms, rate measurements and the mode of formation of boiler deposits; thermal radiation and heat transfer properties of boiler deposits; measures to combat boiler fouling and slagging; some specific ash-related problems with US Coals; use of additives in coal fired boilers; high temperature corrosion in coal-fired plants; ash impaction erosion wear; low temeprature fouling and corrosion; comparison of ash-related problems in pulverized fuel and other coal-fired systems.

  1. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1993--June 1993

    SciTech Connect

    Not Available

    1993-07-30

    Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a ``Coal-Fired Combustion System for Industrial Process Heating Applications`` is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the designs of the remaining major components of the integrated system were completed and the equipment was ordered. DOE has elected to modify the scope of the existing R&D program being conducted under this contract to include testing of a simulated TSCA incinerator ash. The modification will be in the form of an additional Task (Task 8 -- TSCA Ash Testing) to the original Statement of Work.

  2. Oxy-coal Combustion Studies

    SciTech Connect

    Wendt, J.; Eddings, E.; Lighty, J.; Ring, T.; Smith, P.; Thornock, J.; Y Jia, W. Morris; Pedel, J.; Rezeai, D.; Wang, L.; Zhang, J.; Kelly, K.

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  3. Coal combustion science. Quarterly progress report, April 1993--June 1993

    SciTech Connect

    Hardesty, D.R.

    1994-05-01

    This document is a quarterly status report of the Coal Combustion Science Project that is being conducted at the Combustion Research Facility, Sandia National Laboratories. The information reported is for Apr-Jun 1993. The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the PETC Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. The objective of the kinetics and mechanisms of pulverized coal char combustion task is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: kinetics of heterogeneous fuel particle populations; char combustion kinetics at high carbon conversion; the role of particle structure and the char formation process in combustion and; unification of the Sandia char combustion data base. This data base on the high temperature reactivities of chars from strategic US coals will permit identification of important fuel-specific trends and development of predictive capabilities for advanced coal combustion systems. The objective of the fate of inorganic material during coal combustion task is the establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of inorganic material during coal combustion as a function of coal type, particle size and temperature, the initial forms and distribution of inorganic species in the unreacted coal, and the local gas temperature and composition. In addition, optical diagnostic capabilities are being developed for in situ, real-time detection of inorganic vapor species and surface species during ash deposition. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  4. Modelling of CWS combustion process

    NASA Astrophysics Data System (ADS)

    Rybenko, I. A.; Ermakova, L. A.

    2016-10-01

    The paper considers the combustion process of coal water slurry (CWS) drops. The physico-chemical process scheme consisting of several independent parallel-sequential stages is offered. This scheme of drops combustion process is proved by the particle size distribution test and research stereomicroscopic analysis of combustion products. The results of mathematical modelling and optimization of stationary regimes of CWS combustion are provided. During modeling the problem of defining possible equilibrium composition of products, which can be obtained as a result of CWS combustion processes at different temperatures, is solved.

  5. Coal combustion by wet oxidation

    SciTech Connect

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  6. Nitrogen release during coal combustion

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  7. Oxy Coal Combustion at the US EPA

    EPA Science Inventory

    Oxygen enriched coal (oxy-coal) combustion is a developing, and potentially a strategically key technology intended to accommodate direct CO2 recovery and sequestration. Oxy-coal combustion is also intended for retrofit application to existing power plants. During oxy-coal comb...

  8. Study of instrumentation needs for process control and safety in coal fluidized-bed combustion systems

    SciTech Connect

    Herzenberg, C.L.; Griggs, K.E.; Henry, R.F.; Podolski, W.F.

    1981-02-01

    A study was conducted to evaluate the current state of the art of instrumentation for planned and operating fluidized-bed combustion systems. This study is intended to identify instrumentation needs and serve as a data base for projects to develop this instrumentation. A considerable number of needs for measurements for which presently available instrumentation is not suitable were reported by respondents. The identified deficiencies are presented with the associated physical parameter ranges for FBC processes. New techniques and instrumentation under development, as well as some available alternative instruments, are discussed briefly. Also, newly instituted mechanisms for technical information exchange on instrumentation for fossil energy applications are identified. Development of instruments to meet the identified measurement deficiencies is recommended in order to ensure the feasibility of automatic control of large-scale fluidized-bed combustion systems, and to advance the state of the art of fluidized-bed combustion technology.

  9. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1993--September 1993

    SciTech Connect

    Not Available

    1994-01-30

    The Pittsburgh Energy Technology Center (PETC) of the US Department of Energy awarded Vortec Corporation this Phase III contract (No. DE-AC22-91PC91161) for the development of {open_quotes}A Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes}. The effective contrast start date was September 3, 1991. The contract period of performance is 36 months. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. Final detailed installation designs for the integrated test system configuration are being completed. The equipment is being fabricated and deliveries have begun. The industry funded testing consisted of vitrifying Spent Aluminum Potliner (SPL) which is a listed hazardous waste. This testing has verified that SPL can be vitrified into a safe recyclable glass product.

  10. TOXIC SUBSTANCES FROM COAL COMBUSTION

    SciTech Connect

    A KOLKER; AF SAROFIM; CL SENIOR; FE HUGGINS; GP HUFFMAN; I OLMEZ; J LIGHTY; JOL WENDT; JOSEPH J HELBLE; MR AMES; N YAP; R FINKELMAN; T PANAGIOTOU; W SEAMES

    1998-12-08

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, the Lignite Research Council, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO combustion systems, and new power generation x plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1998 through 30 September 1998. During this period distribution of all three Phase II coals was completed. Standard analyses for the whole coal samples were also completed. Mössbauer analysis of all project coals and fractions received to date has been completed in order to obtain details of the iron mineralogy. The analyses of arsenic XAFS data for two of the project coals and for some high arsenic coals have been completed. Duplicate splits of the Ohio 5,6,7 and North Dakota lignite samples were taken through all four steps of the selective leaching procedure. Leaching analysis of the Wyodak coal has recently commenced. Preparation of polished coal/epoxy pellets for probe/SEM studies is underway. Some exploratory mercury LIII XAFS work was carried

  11. Fluidized bed coal combustion reactor

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L. (Inventor)

    1981-01-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  12. Fluidized bed coal combustion reactor

    SciTech Connect

    Moynihan, P.I.; Young, D.L.

    1981-09-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor. Official Gazette of the U.S. Patent and Trademark Office

  13. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1992--September 1992

    SciTech Connect

    Not Available

    1992-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. ne primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order toevaluate its potential marketability. During the current reporting period, three preliminary coal-fired tests were successfully completed. These tests used industrial boiler flyash, sewer sludge ash, and waste glass collet as feedstocks. The coal-fired ash vitrification tests are considered near term potential commercial applications of the CMS technology. The waste glass cullet provided necessary dam on the effect of coal firing with respect to vitrified product oxidation state. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the proof-of-concept tests are continuing. The economic evaluation of commercial scale CMS processes is continuing. Preliminary designs for 15, 25, 100 and 400 ton/day systems are in progress. This dam will serve as input data to the life cycle cost analysis which will be-an integral part of the CMS commercialization plan.

  14. TOXIC SUBSTANCES FROM COAL COMBUSTION

    SciTech Connect

    Kolker, A.; Sarofim, A.F.; Palmer, C.A.; Huggins, F.E.; Huffman, G.P.; Lighty, J.; Veranth, J.; Helble, J.J.; Wendt, J.O.L.; Ames, M.R.; Finkelman, R.; Mamani-Paco, M.; Sterling, R.; Mroczkowsky, S.J.; Panagiotou, T.; Seames, W.

    1999-05-10

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environ-mental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 January 1999 to 31 March 1999. During this period, a full Program Review Meeting was held at the University of Arizona. At this meeting, the progress of each group was reviewed, plans for the following 9 month period were discussed, and action items (principally associated with the transfer of samples and reports among the various investigators) were identified.

  15. Coal Combustion Science. Quarterly progress report, October--December 1994

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H.; Yang, N.Y.C.

    1996-02-01

    The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: Task 1--Kinetics and mechanisms of pulverized coal char combustion; and Task 2--deposit growth and property development in coal-fired furnaces. The objective of task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: (a) kinetics of heterogeneous fuel particle populations; (b) char combustion kinetics at high carbon conversion; (c) the role of particle structure and the char formation process in combustion and; (d) unification of the Sandia char combustion data base. The objectives of Task 2 are to provide a self-consistent database of simultaneously measured, time-resolved, ash deposit properties in well-controlled and well-defined environments and to provide analytical expressions that relate deposit composition and structure to deposit properties of immediate relevance to PETC`s Combustion 2000 program. The task include the development and use of diagnostics to monitor, in situ and in real time, deposit properties, including information on both the structure and composition of the deposits.

  16. Plane flame furnace combustion tests on JPL desulfurized coal

    NASA Technical Reports Server (NTRS)

    Reuther, J. J.; Kim, H. T.; Lima, J. G. H.

    1982-01-01

    The combustion characteristics of three raw bituminous (PSOC-282 and 276) and subbituminous (PSOC-230) coals, the raw coals partially desulfurized (ca -60%) by JPL chlorinolysis, and the chlorinated coals more completely desulfurized (ca -75%) by JPL hydrodesulfurization were determined. The extent to which the combustion characteristics of the untreated coals were altered upon JPL sulfur removal was examined. Combustion conditions typical of utility boilers were simulated in the plane flame furnace. Upon decreasing the parent coal voltaile matter generically by 80% and the sulfur by 75% via the JPL desulfurization process, ignition time was delayed 70 fold, burning velocity was retarded 1.5 fold, and burnout time was prolonged 1.4 fold. Total flame residence time increased 2.3 fold. The JPL desulfurization process appears to show significant promise for producing technologically combustible and clean burning (low SO3) fuels.

  17. Metal attenuation processes in a landfill containing coal combustion waste: Implications for remediation.

    SciTech Connect

    Barton, Christopher; Paddock, Lindy; Romanek, Christopher; Maharaj, Sally; Seaman, John

    2005-03-01

    The 488-D Ash Basin (488-DAB) is an unlined, earthen landfill containing approximately 1 million t of dry ash and coal reject material at the U.S. Department of Energy’s Savannah River Site, South Carolina. The pyritic nature of the coal rejects has resulted in the formation of acidic drainage, which has contributed to groundwater deterioration and threatened biota in adjacent wetlands. Establishment of a vegetation cover to both deplete oxygen through biological means and optimize evapotranspiration has been established as a remedial alternative for reducing acidic drainage generation in the 488-DAB. To determine the potential benefits of a cover, a series of characterization studies were conducted prior to field deployment to gain a better understanding of the metal attenuation processes and to use water quality and substrate data to evaluate the potential effectiveness of this remedial approach. The characterization study indicated that metal attenuation was primarily controlled by fluctuating redox and pH gradients associated with alternating saturated and unsaturated conditions in the basin. Based on this information, a vegetative cover could reduce the production of acid leachate over time, pending that oxygen transport to the subsurface is limited.

  18. Modeling of pulverized coal combustion processes in a vortex furnace of improved design. Part 2: Combustion of brown coal from the Kansk-Achinsk Basin in a vortex furnace

    NASA Astrophysics Data System (ADS)

    Krasinsky, D. V.; Salomatov, V. V.; Anufriev, I. S.; Sharypov, O. V.; Shadrin, E. Yu.; Anikin, Yu. A.

    2015-03-01

    This paper continues with the description of study results for an improved-design steam boiler vortex furnace, for the full-scale configuration of which the numerical modeling of a three-dimensional turbulent two-phase reacting flow has been performed with allowance for all the principal heat and mass transfer processes in the torch combustion of pulverized Berezovsk brown coal from the Kansk-Achinsk Basin. The detailed distributions of velocity, temperature, concentration, and heat flux fields in different cross sections of the improved vortex furnace have been obtained. The principal thermoengineering and environmental characteristics of this furnace are given.

  19. Managing coal combustion residues in mines

    SciTech Connect

    2006-07-01

    Burning coal in electric utility plants produces, in addition to power, residues that contain constituents which may be harmful to the environment. The management of large volumes of coal combustion residues (CCRs) is a challenge for utilities, because they must either place the CCRs in landfills, surface impoundments, or mines, or find alternative uses for the material. This study focuses on the placement of CCRs in active and abandoned coal mines. The Committee on Mine Placement of Coal Combustion Wastes of the National Research Council believes that placement of CCRs in mines as part of the reclamation process may be a viable option for the disposal of this material as long as the placement is properly planned and carried out in a manner that avoids significant adverse environmental and health impacts. This report discusses a variety of steps that are involved in planning and managing the use of CCRs as minefills, including an integrated process of CCR characterization and site characterization, management and engineering design of placement activities, and design and implementation of monitoring to reduce the risk of contamination moving from the mine site to the ambient environment. Enforceable federal standards are needed for the disposal of CCRs in minefills to ensure that states have adequate, explicit authority and that they implement minimum safeguards. 267 refs., 6 apps.

  20. Burning of suspended coal-water slurry droplet with oil as combustion additive

    SciTech Connect

    Yao, S.C.; Manwani, P.

    1986-10-01

    Coal-water slurries have been regarded as a potential substitute for heavy fuel oil. Various demonstrations of coal-water slurry combustion have been performed; however, a fundamental understanding of how the combustion process of a slurry fuel is enhanced is still not adequate. The combustion of coal-water mixture droplets suspended on microthermocouples has been investigated. It was found that droplets of lignite coal (which is a noncaking coal) burn effectively; however, droplets of bituminous coal (which is a caking coal) are relatively difficult to burn. During the heat-up of bituminous coal-water slurry droplets may turn to ''popcorn'' and show significant agglomeration. The incomplete combustion of coal-water slurry droplets in furnaces has been reported, and this is a drawback of this process. The objective of the present study is to explore the possibility of enhancing the combustion of coal-water slurry droplets with the use of a combustible emulsified oil.

  1. Optimal thermionic energy conversion with established electrodes for high-temperature topping and process heating. [coal combustion product environments

    NASA Technical Reports Server (NTRS)

    Morris, J. F.

    1980-01-01

    Applied research-and-technology (ART) work reveals that optimal thermionic energy conversion (TEC) with approximately 1000 K to approximately 1100 K collectors is possible using well established tungsten electrodes. Such TEC with 1800 K emitters could approach 26.6% efficiency at 27.4 W/sq cm with approximately 1000 K collectors and 21.7% at 22.6 W/sq cm with approximately 1100 K collectors. These performances require 1.5 and 1.7 eV collector work functions (not the 1 eV ultimate) with nearly negligible interelectrode losses. Such collectors correspond to tungsten electrode systems in approximately 0.9 to approximately 6 torr cesium pressures with 1600 K to 1900 K emitters. Because higher heat-rejection temperatures for TEC allow greater collector work functions, interelectrode loss reduction becomes an increasingly important target for applications aimed at elevated temperatures. Studies of intragap modifications and new electrodes that will allow better electron emission and collection with lower cesium pressures are among the TEC-ART approaches to reduced interelectrode losses. These solutions will provide very effective TEC to serve directly in coal-combustion products for high-temperature topping and process heating. In turn this will help to use coal and to use it well.

  2. Plasma-supported coal combustion in boiler furnace

    SciTech Connect

    Askarova, A.S.; Karpenko, E.I.; Lavrishcheva, Y.I.; Messerle, V.E.; Ustimenko, A.B.

    2007-12-15

    Plasma activation promotes more effective and environmentally friendly low-rank coal combustion. This paper presents Plasma Fuel Systems that increase the burning efficiency of coal. The systems were tested for fuel oil-free start-up of coal-fired boilers and stabilization of a pulverized-coal flame in power-generating boilers equipped with different types of burners, and burning all types of power-generating coal. Also, numerical modeling results of a plasma thermochemical preparation of pulverized coal for ignition and combustion in the furnace of a utility boiler are discussed in this paper. Two kinetic mathematical models were used in the investigation of the processes of air/fuel mixture plasma activation: ignition and combustion. A I-D kinetic code PLASMA-COAL calculates the concentrations of species, temperatures, and velocities of the treated coal/air mixture in a burner incorporating a plasma source. The I-D simulation results are initial data for the 3-D-modeling of power boiler furnaces by the code FLOREAN. A comprehensive image of plasma-activated coal combustion processes in a furnace of a pulverized-coal-fired boiler was obtained. The advantages of the plasma technology are clearly demonstrated.

  3. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, October 1992--December 1992

    SciTech Connect

    Not Available

    1993-01-29

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent relining the separator/reservoir and the cyclone melter. The relinings were completed, the cyclonemelter was reinstalled, and the test system was returned to operational status. The wet ESP was delivered and placed on its foundation. The focus during the upcoming months will be completing the integration ofthe wet ESP and conducting the first industrial proof-of-concept test. The other system modifications are well underway with the designs of the recuperator installation and the batch/coal feed system progressing smoothly. The program is still slightly behind the original schedule but it is anticipated that it will be back on schedule by the end of the year. The commercialization planning is continuing with the identification of seven potential near-term commercial demonstration opportunities.

  4. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on Combustion Characterization of Beneficiated Coal-Based Fuels.'' The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE's laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  5. Coal combustion: Science and technology of industrial and utility applications

    SciTech Connect

    Feng, J.

    1988-01-01

    Despite the competition of oil and gas and the increasing importance of nuclear power, coal is still one of the main sources of energy in the world. In some regions of the world, the reserve of oil and natural gas is nearly depleted. The supply of such fuels relies on shipment from foreign countries, and may be vulnerable to political crisis, while coals are still abundant and easily available. Therefore, the technology of burning coal for energy, which seems rather old, has not lost its vitality and is in fact developing fast. Because of industry development, especially in developing countries, more and more coal is burned each year. If coal is not burned properly, it may pollute the environment and affect the ecological balance of the surrounding regions. Great attention has been paid to curb these issues, and significant progress has been achieved. Technology of desulfurization of flue gases, low nitrogen oxide coal burners, and also the technology of clean burning of coal by fluidized-bed combustion have all been developed and commercialized. Further improvements are under development. At the same time, new techniques have been used in the measurements and diagnoses of coal combustion. These new techniques facilitate more efficient and cleaner burning of coal. Although coal combustion is a very complicated physiochemical phenomenon, the use of the computer enables and pushes forward the theoretical analysis of coal combustion. Besides, the mathematical modelling of the coal combustion process is also a fast progressing field of research and encouraging results have been obtained by scientists throughout the world. This book compiles the papers presented in the conference on the subject of clean cool technology and fluidized-bed combustion.

  6. Coal Combustion Science quarterly progress report, April--June 1990

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    This document provides a quarterly status report of the Coal Combustion Science Program that is being conducted at the Combustion, Research Facility, Sandia National Laboratories, Livermore, California. Coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 56 refs., 25 figs., 13 tabs.

  7. SPONTANEOUS COAL COMBUSTION; MECHANISMS AND PREDICTION.

    USGS Publications Warehouse

    Herring, James R.; Rich, Fredrick J.

    1983-01-01

    Spontaneous ignition and combustion of coal is a major problem to the coal mining, shipping, and use industries; unintentional combustion causes loss of the resource as well as jeopardy to life and property. The hazard to life is especially acute in the case of underground coal mine fires that start by spontaneous ignition. It is the intention of this research to examine previously suggested causes of spontaneous ignition, to consider new evidence, and to suggest an experimental approach to determine which of these suggested causes is relevant to western U. S. coal. This discussion focuses only on causes and mechanism of spontaneous ignition.

  8. Coal combustion products: trash or treasure?

    SciTech Connect

    Hansen, T.

    2006-07-15

    Coal combustion by-products can be a valuable resource to various industries. The American Coal Ash Association (ACAA) collects data on production and uses of coal combustion products (CCPs). 122.5 million tons of CCPs were produced in 2004. The article discusses the results of the ACCA's 2004 survey. Fly ash is predominantly used as a substitute for Portland cement; bottom ash for structural fill, embankments and paved road cases. Synthetic gypsum from the FGD process is commonly used in wallboard. Plant owners are only likely to have a buyer for a portion of their CCPs. Although sale of hot water (from Antelope Valley Station) from condensers for use in a fish farm to raise tilapia proved unviable, the Great Plains Synfuels Plant which manufactures natural gas from lignite produces a wide range of products including anhydrous ammonia, phenol, krypton, carbon dioxide (for enhanced oil recovery), tar oils and liquid nitrogen. ACCA's goal is to educate people about CCPs and how to make them into useful products, and market them, in order to reduce waste disposal and enhance revenue. The article lists members of the ACCA. 2 photos., 1 tab.

  9. Combustion of Coal/Oil/Water Slurries

    NASA Technical Reports Server (NTRS)

    Kushida, R. O.

    1982-01-01

    Proposed test setup would measure combustion performance of new fuels by rapidly heating a droplet of coal/oil/water mixture and recording resulting explosion. Such mixtures are being considered as petroleum substitutes in oil-fired furnaces.

  10. COSTS FOR ADVANCED COAL COMBUSTION TECHNOLOGIES

    EPA Science Inventory

    The report gives results of an evaluation of the development status of advanced coal combustion technologies and discusses the preparation of performance and economic models for their application to electric utility plants. he technologies addressed were atmospheric fluidized bed...

  11. Coal Combustion Products Extension Program

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2006-01-11

    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to 40% by 2010, the CCP Extension Program be

  12. The coal slime slurry combustion technology

    SciTech Connect

    Li, Y.; Xu, Z.

    1997-12-31

    This paper presents the coal slime slurry combustion technology in circulating fluidized bed (CFB) boilers. The technique is that the slurry-based flow from the concentrator in the coal washery plant directly feeds into the fluidized bed by pump for combustion after a simple filtration and enrichment to an approximate concentration of 50% of coal. The coal slime slurry can burn in a CFB boiler alone or jointly with coal refuse. The technique has been used in a 35 t/h (6MWe) CFB for power generation. The result shows that the combustion efficiency is over 96% and boiler thermal efficiency is over 77%. As compared with burning coal refuse alone, the thermal efficiency was improved by 3--4 percent. This technology is simple, easy to operate and reliable. It is an effective way to utilize coal slime slurry. It has a practical significance for saving coal resources and reducing environmental pollution near coal mine areas. As a clean coal technology, it will result in great social, environmental and economic benefits.

  13. Compilation of Sandia coal char combustion data and kinetic analyses

    SciTech Connect

    Mitchell, R.E.; Hurt, R.H.; Baxter, L.L.; Hardesty, D.R.

    1992-06-01

    An experimental project was undertaken to characterize the physical and chemical processes that govern the combustion of pulverized coal chars. The experimental endeavor establishes a database on the reactivities of coal chars as a function of coal type, particle size, particle temperature, gas temperature, and gas and composition. The project also provides a better understanding of the mechanism of char oxidation, and yields quantitative information on the release rates of nitrogen- and sulfur-containing species during char combustion. An accurate predictive engineering model of the overall char combustion process under technologically relevant conditions in a primary product of this experimental effort. This document summarizes the experimental effort, the approach used to analyze the data, and individual compilations of data and kinetic analyses for each of the parent coals investigates.

  14. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1993--September 1993

    SciTech Connect

    Not Available

    1993-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase 3 research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the major effort was completing some of the system modification installation designs, completing industry funded testing, developing a surrogate TSCA ash composition, and completing the TSCA ash Test Plan. The installation designs will be used for the equipment modifications planned for the end of CY 93. The industry funded testing consisted of vitrifying Spent Aluminum Potliner (SPL) which is a listed hazardous waste. This testing has verified that SPL can be vitrified into a safe, recyclable glass product. Some results from this testing are provided in Section 2.2.1. The surrogate TSCA ash composition was developed with input from various DOE laboratories and subcontractors. The surrogate ash consists of a mixture of MSW fly ash and bottom ash spiked with heavy metal contaminants. The levels of metal additives are sufficient to ascertain the partitioning of the contaminants between the glass and effluent flow streams. Details of the surrogate composition and the planned testing is provided in Section 4.2.2.

  15. TRACE METAL TRANSFORMATION MECHANISMS DURING COAL COMBUSTION

    EPA Science Inventory

    The article reviews mechanisms governing the fate of trace metals during coal combustion and presents new theoretical results that interpret existing data. Emphasis is on predicting the size-segregated speciation of trace metals in pulverized-coal-fired power plant effluents. Thi...

  16. Coal gasification cogeneration process

    SciTech Connect

    Marten, J.H.

    1990-10-16

    This patent describes a process for the coproduction of a combustible first gas stream usable as an energy source, a sulfur-dioxide-containing second gas stream usable as a source for oxidant in the gasification of coal and a sulfur-dioxide-containing third gas stream usable as a feedstock for the production of sulfuric acid. It comprises: reacting coal in a coal gasification zone in the presence of an oxidant under partial coal-gasifying conditions to produce carbonaceous char and a crude gas stream; separating sulfur-containing compounds from the crude gas stream in a sulfur recovery zone to produce a combustible first gas stream and elemental sulfur; reacting the carbonaceous char and gypsum in a reaction zone in proportions such that the non-gypsum portion of the carbonaceous char and gypsum mixture contains sufficient reducing potential to reduce sulfur in the gypsum to gaseous compounds of sulfur in a +4 or lower oxidation state under reducing conditions to produce first a sulfur-dioxide-containing second gas stream which contains weaker SO{sub 2} produced in an early stage of the reaction zone and removed from the reaction zone, and then a sulfur-dioxide-containing third gas stream which contains concentrated SO{sub 2} recovered from a later stage of the reaction zone.

  17. Kinetics of coal combustion: Part 2, Mechanisms and kinetics of coal volatiles combustion

    SciTech Connect

    Gat, N.; Wolff, M.F.; Petach, M.B. )

    1988-12-01

    Presently very little is known about the combustion characteristics of mixtures of hydrocarbon fuels. Even less is known about the combustion of coal volatiles which are complex mixtures of light and high molecular weight hydrocarbons. This issue pertains not only to coal volatiles but also to the combustion of synthetic fuels, liquefaction and coal gasification products. The subject in general has been given very little attention in the literature. As a consequence, current modeling methods are based on assumptions which are not thoroughly validated and verified. The current investigation addressed this very problem of the combustion of mixtures of hydrocarbon fuels. 29 refs., 35 figs., 5 tabs.

  18. Health impacts of domestic coal combustion

    SciTech Connect

    Finkelman, R.B.

    1999-07-01

    The US Environmental Protection Agency (EPA) has concluded that, with the possible exception of mercury, there is no compelling evidence to indicate that emissions from coal-burning electric utility generators cause human health problems. The absence of detectable health problems is in part due to the fact that the coals burned in the US generally contain low to modest concentrations of potentially toxic trace elements and that many coal-burning utilities employ sophisticated pollution control systems that efficiently reduce the emissions of hazardous elements. This is not so in many developing countries, especially in homes where coal is used for heating and cooking. Domestic use of coal can present serious human health problems because the coals are generally mined locally with little regard to their composition and the coals are commonly burned in poorly vented or unvented stoves directly exposing residents to the emissions. In China alone several hundred million people commonly burn raw coal in unvented stoves that permeate their homes with high levels of toxic metals and organic compounds. At least 3,000 people in Guizhou Province in southwest China are suffering from severe arsenic poisoning. The primary source of the arsenic appears to be consumption of chili peppers dried over fires fueled with high-arsenic coal. Coal's in the region contain up to 35,000 ppm arsenic. Chili peppers dried over these high-arsenic coal fires absorb 500 ppm arsenic on average. More than 10 million people in Guizhou Province and surrounding areas suffer from dental and skeletal fluorosis. The excess fluorine is due to eating corn dried over burning briquettes made from high-fluorine coals and high-fluoring clay binders. Polycyclic aromatic hydrocarbons formed during coal combustion are believed to cause or contribute to the high incidence of esophageal and lung cancers in parts of China. Domestic coal combustion has also caused selenium poisoning and possibly mercury poisoning

  19. Diesel engine combustion processes

    SciTech Connect

    1995-12-31

    Diesel Engine Combustion Processes guides the engineer and research technician toward engine designs which will give the ``best payoff`` in terms of emissions and fuel economy. Contents include: Three-dimensional modeling of soot and NO in a direct-injection diesel engine; Prechamber for lean burn for low NOx; Modeling and identification of a diesel combustion process with the downhill gradient search method; The droplet group micro-explosions in W/O diesel fuel emulsion sprays; Combustion process of diesel spray in high temperature air; Combustion process of diesel engines at regions with different altitude; and more.

  20. The development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January 1992--March 1992

    SciTech Connect

    Not Available

    1992-07-16

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Coal-Fired Combustion System for Industrial Process Heating Applications has been selected for Phase III development under contract DE-AC22-91PC91161. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting, recycling, and refining processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase HI research effort is being focused on the development of a process heater system to be used for producing glass frits and wool fiber from boiler and incinerator ashes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The economic evaluation of commercial scale CMS processes has begun. In order to accurately estimate the cost of the primary process vessels, preliminary designs for 25, 50, and 100 ton/day systems have been started under Task 1. This data will serve as input data for life cycle cost analysis performed as part of techno-economic evaluations. The economic evaluations of commercial CMS systems will be an integral part of the commercialization plan.

  1. Biomedically relevant chemical and physical properties of coal combustion products.

    PubMed Central

    Fisher, G L

    1983-01-01

    The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

  2. Marketable products from gypsum, a coal combustion byproduct derived from a wet flue gas desulfurization process

    SciTech Connect

    Chou, M.I.M.; Ghiassi, K.; Lytle, J.M.; Chou, S.J.; Banerjee, D.D.

    1998-04-01

    For two years the authors have been developing a process to produce two marketable products, ammonium sulfate fertilizer and precipitated calcium carbonate (PCC), from wet limestone flue gas desulfurization (FGD) by-product gypsum. Phase I of the project focused on the process for converting FGD-gypsum to ammonium sulfate fertilizer with PCC produced as a by-product during the conversion. Early cost estimates suggested that the process was economically feasible when granular size ammonium sulfate crystals were produced. However, sale of the by-product PCC for high-value commercial application could further improve the economics of the process. The results of our evaluation of the market potential of the PCC by-product are reported in this paper. The most significant attributes of carbonate fillers that determine their usefulness in industry are particle size (i.e. fineness) and shape, whiteness (brightness), and mineralogical and chemical purity. The PCC produced from the FGD gypsum obtained from the Abbott Power Plant at the University of Illinois Urbana-Champaign campus are pure calcite with a CaCO{sub 3} content greater than 98%, 3% higher than the minimum requirement of 95%. However, the size, shape, and brightness of the PCC particles are suitable only for certain applications. Impurities in the gypsum from Abbott power plant influence the whiteness of the PCC products. Test results suggested that, to obtain gypsum that is pure enough to produce a high whiteness PCC for high value commercial applications, limestone with minimum color impurities should be used during the FGD process. Alternatively, purification procedures to obtain the desired whiteness of the FGD-gypsum can be used. Further improvement in the overall qualities of the PCC products should lead to a product that is adequate for high-value paper applications.

  3. Coal desulfurization by chlorinolysis production and combustion test evaluation of product coals

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Daly, D.

    1982-01-01

    Laboratory-scale screening tests were carried out on coal from Harrison County, Ohio to establish chlorination and hydrodesulfurization conditions for the batch reactor production of chlorinolysis and chlorinolysis-hydrodesulfurized coals. In addition, three bituminous coals, were treated on the lab scale by the chlorinolysis process to provide 39 to 62% desulfurization. Two bituminous coals and one subbituminous coal were then produced in 11 to 15 pound lots as chlorinolysis and hydrodesulfurized coals. The chlorinolysis coals had a desulfurization of 29-69%, reductions in voltatiles and hydrogen. Hydrodesulfurization provided a much greater desulfurization (56-86%), reductions in volatiles and hydrogen. The three coals were combustion tested in the Penn State ""plane flame furnace'' to determine ignition and burning characteristics. All three coals burned well to completion as: raw coals, chlorinolysis processed coals, and hydrodesulfurized coals. The hydrodesulfurized coals experienced greater ignition delays and reduced burning rates than the other coals because of the reduced volatile content. It is thought that the increased open pore volume in the desulfurized-devolatilized coals compensates in part for the decreased volatiles effect on ignition and burning.

  4. Novel polymer membrane process for pre-combustion CO{sub 2} capture from coal-fired syngas

    SciTech Connect

    Merkel, Tim

    2011-09-14

    This final report describes work conducted for the Department of Energy (DOE NETL) on development of a novel polymer membrane process for pre-combustion CO{sub 2} capture from coalfired syngas (award number DE-FE0001124). The work was conducted by Membrane Technology and Research, Inc. (MTR) from September 15, 2009, through December 14, 2011. Tetramer Technologies, LLC (Tetramer) was our subcontract partner on this project. The National Carbon Capture Center (NCCC) at Wilsonville, AL, provided access to syngas gasifier test facilities. The main objective of this project was to develop a cost-effective membrane process that could be used in the relatively near-term to capture CO{sub 2} from shifted syngas generated by a coal-fired Integrated Gasification Combined Cycle (IGCC) power plant. In this project, novel polymeric membranes (designated as Proteus™ membranes) with separation properties superior to conventional polymeric membranes were developed. Hydrogen permeance of up to 800 gpu and H{sub 2}/CO{sub 2} selectivity of >12 was achieved using a simulated syngas mixture at 150°C and 50 psig, which exceeds the original project targets of 200 gpu for hydrogen permeance and 10 for H{sub 2}/CO{sub 2} selectivity. Lab-scale Proteus membrane modules (with a membrane area of 0.13 m{sup 2}) were also developed using scaled-up Proteus membranes and high temperature stable module components identified during this project. A mixed-gas hydrogen permeance of about 160 gpu and H{sub 2}/CO{sub 2} selectivity of >12 was achieved using a simulated syngas mixture at 150°C and 100 psig. We believe that a significant improvement in the membrane and module performance is likely with additional development work. Both Proteus membranes and lab-scale Proteus membrane modules were further evaluated using coal-derived syngas streams at the National Carbon Capture Center (NCCC). The results indicate that all module components, including the Proteus membrane, were stable under the field

  5. MECHANISMS AND OPTIMIZATION OF COAL COMBUSTION

    SciTech Connect

    Kyriacos Zygourakis

    2000-10-31

    The completed research project has made some significant contributions that will help us meet the challenges outlined in the previous section. One of the major novelties of our experimental approach involves the application of video microscopy and digital image analysis to study important transient phenomena (like particle swelling and ignitions) occurring during coal pyrolysis and combustion. Image analysis was also used to analyze the macropore structure of chars, a dominant factor in determining char reactivity and ignition behavior at high temperatures where all the commercial processes operate. By combining advanced experimental techniques with mathematical modeling, we were able to achieve the main objectives of our project. More specifically: (1) We accurately quantified the effect of several important process conditions (like pyrolysis heating rate, particle size, heat treatment temperature and soak time) on the combustion behavior of chars. These measurements shed new light into the fundamental mechanisms of important transient processes like particle swelling and ignitions. (2) We developed and tested theoretical models that can predict the ignition behavior of char particles and their burn-off times at high temperatures where intraparticle diffusional limitations are very important.

  6. Lump wood combustion process

    NASA Astrophysics Data System (ADS)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  7. Coal combustion: Effect of process conditions on char reactivity. Quarterly technical report, January 1, 1995--March 31, 1995

    SciTech Connect

    Zygourakis, K.

    1995-08-01

    The project will quantify the effect of the following pyrolysis conditions on the macropore structure and on the subsequent reactivity of chars: (a) pyrolysis heating rate; (b) final heat treatment temperature (HTT); (c) duration of heat treatment at HTT (or soak time); (d) pyrolysis atmosphere (N{sub 2} or O{sub 2}/N{sub 2} mixtures); (e) coal particle size (100--1000 {mu}m in diameter); (f) sulfur-capturing additives (limestone); and (g) coal rank. Pyrolysis experiments will be carried out for three coals from the Argonne collection: (1) a high-volatile bituminous coal with high ash content (Illinois {number_sign}6), (2) a bituminous coal with low ash content (Utah Blind Canyon) and (3) a lower rank subbituminous coal (Wyodak-Anderson seam). A systematic study was carried out in the past quarter to validate the mathematical model for ignition phenomena presented in the previous quarterly report. Model predictions of the effect of pyrolysis heating rate, particle size, and oxygen concentration on ignition behavior are in excellent agreement with experimental results. Moreover, our results show that the model can be used to estimate the particle temperature during ignition and the minimum ignition temperature for various process conditions.

  8. Pulverized coal combustion characterization at the KEPRI

    SciTech Connect

    Cha, D.J.; Kim, S.C.; Bae, B.H.; Kim, T.H.; Shin, Y.J.; Lee, H.D.; Park, O.Y.; Choi, B.S.

    1997-12-31

    A pilot-scale combustion test facility that can be utilized to burn pulverized coals such as anthracite coals, bituminous coals, and their blends at the rate of 200 kg/hr has been constructed to study coal-related impacts on utility boiler operations. The impacts include pulverizer performance, combustion stability, slagging, fouling, heat transfer, erosion, corrosion, pollutant emission, etc. The facility, a scale-down model of an existing boiler in Korea, consists of all the necessary components for the boiler with a distributed control system except steam generation components which have been replaced with slag panels, fouling probes, and heat exchangers. The facility, in addition, incorporates the advanced boiler technologies including tangentially-fired burners, flue gas recirculation, direct sorbent injection for desulfurization, electrostatic precipitator, wet scrubber, etc., and employs an opacity meter and gas analyzers. Low NOx burners and gas reburning system will be facilitated in the future to study low emission boiler systems being demonstrated in the developed countries. This paper represents preliminary test results including flame shapes, fouling based on the fouling factor, and pollutant emission with different coals and combustion aerodynamics. Flow fields in the furnace have been changed by varying the swirl number and the burner configurations in terms of single-wall, opposed-wall, and corner firing mode. An extensive investigation will continue to find optimum conditions for various coals of interest.

  9. Coal combustion aerothermochemistry research. Final report

    SciTech Connect

    Witte, A.B.; Gat, N.; Denison, M.R.; Cohen, L.M.

    1980-12-15

    On the basis of extensive aerothermochemistry analyses, laboratory investigations, and combustor tests, significant headway has been made toward improving the understanding of combustion phenomena and scaling of high swirl pulverized coal combustors. A special attempt has been made to address the gap between scientific data available on combustion and hardware design and scaling needs. Both experimental and theoretical investigations were conducted to improve the predictive capability of combustor scaling laws. The scaling laws derived apply to volume and wall burning of pulverized coal in a slagging high-swirl combustor. They incorporate the findings of this investigation as follows: laser pyrolysis of coal at 10/sup 6/ K/sec and 2500K; effect of coal particle shape on aerodynamic drag and combustion; effect of swirl on heat transfer; coal burnout and slag capture for 20 MW/sub T/ combustor tests for fine and coarse coals; burning particle trajectories and slag capture; particle size and aerodynamic size; volatilization extent and burnout fraction; and preheat level. As a result of this work, the following has been gained: an increased understanding of basic burning mechanisms in high-swirl combustors and an improved model for predicting combustor performance which is intended to impact hardware design and scaling in the near term.

  10. Tripropellant combustion process

    NASA Technical Reports Server (NTRS)

    Kmiec, T. D.; Carroll, R. G.

    1988-01-01

    The addition of small amounts of hydrogen to the combustion of LOX/hydrocarbon propellants in large rocket booster engines has the potential to enhance the system stability. Programs being conducted to evaluate the effects of hydrogen on the combustion of LOX/hydrocarbon propellants at supercritical pressures are described. Combustion instability has been a problem during the development of large hydrocarbon fueled rocket engines. At the higher combustion chamber pressures expected for the next generation of booster engines, the effect of unstable combustion could be even more destructive. The tripropellant engine cycle takes advantage of the superior cooling characteristics of hydrogen to cool the combustion chamber and a small amount of the hydrogen coolant can be used in the combustion process to enhance the system stability. Three aspects of work that will be accomplished to evaluate tripropellant combustion are described. The first is laboratory demonstration of the benefits through the evaluation of drop size, ignition delay and burning rate. The second is analytical modeling of the combustion process using the empirical relationship determined in the laboratory. The third is a subscale demonstration in which the system stability will be evaluated. The approach for each aspect is described and the analytical models that will be used are presented.

  11. CO2 emission of coal spontaneous combustion and its relation with coal microstructure, China.

    PubMed

    Wang, Haiyan; Chen Chen; Huang, Tao; Gao, Wei

    2015-07-01

    Coal spontaneous combustion is widely distributed all over the world. CO2 is the main greenhouse gas emitted by coal spontaneous combustion. In the present study characters of CO2 emitted by 10 typical Chinese coal spontaneous combustion and the influence of raw coal functional group on CO2 was studied. CO2 already exists under normal temperature as coal exposed in atmosphere. Under low temperature, the quality of CO2 released by coal spontaneous combustion is relatively small, but tends to increase. And corresponding with it, the oxygen consumption amount is also small. At medium temperature, the oxygen consumption increases rapidly and CO2 mass release rate begins to increase rapidly. Then, CO2 release rate increase rapidly under relatively high temperature (higher than 673 K). Over 873K, concentration of O2 is 6% and release rate of CO2 tends to be steady. It also concluded that mass ratio of CO to CO2 (CO/CO2) during coal spontaneous combustion was lowerthan 0.10 at low temperature. And then, it increased rapidly at medium temperature and reached to top at about 673 K. At 673-873 K, the ratio decreased again, and did not decrease evidently at about 873K. At temperature higher than 873K, the ratio was about 0.13. During the whole testing temperature range, CO/CO2 was not be higher than 0.26, lower than 0.2. This means that release rate of CO2 was much higher than CO during the whole process of coal spontaneous combustion. Moreover, the gas release quantity of CO2 is positively related with carbony content in raw coal. Carbonyl and carboxyl were both material basis of CO2. PMID:26364484

  12. CO2 emission of coal spontaneous combustion and its relation with coal microstructure, China.

    PubMed

    Wang, Haiyan; Chen Chen; Huang, Tao; Gao, Wei

    2015-07-01

    Coal spontaneous combustion is widely distributed all over the world. CO2 is the main greenhouse gas emitted by coal spontaneous combustion. In the present study characters of CO2 emitted by 10 typical Chinese coal spontaneous combustion and the influence of raw coal functional group on CO2 was studied. CO2 already exists under normal temperature as coal exposed in atmosphere. Under low temperature, the quality of CO2 released by coal spontaneous combustion is relatively small, but tends to increase. And corresponding with it, the oxygen consumption amount is also small. At medium temperature, the oxygen consumption increases rapidly and CO2 mass release rate begins to increase rapidly. Then, CO2 release rate increase rapidly under relatively high temperature (higher than 673 K). Over 873K, concentration of O2 is 6% and release rate of CO2 tends to be steady. It also concluded that mass ratio of CO to CO2 (CO/CO2) during coal spontaneous combustion was lowerthan 0.10 at low temperature. And then, it increased rapidly at medium temperature and reached to top at about 673 K. At 673-873 K, the ratio decreased again, and did not decrease evidently at about 873K. At temperature higher than 873K, the ratio was about 0.13. During the whole testing temperature range, CO/CO2 was not be higher than 0.26, lower than 0.2. This means that release rate of CO2 was much higher than CO during the whole process of coal spontaneous combustion. Moreover, the gas release quantity of CO2 is positively related with carbony content in raw coal. Carbonyl and carboxyl were both material basis of CO2.

  13. Enhanced Combustion Low NOx Pulverized Coal Burner

    SciTech Connect

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for economic

  14. [Distribution of fluoride in the combustion products of coal].

    PubMed

    Liu, Jianzhong; Qi, Qingjie; Zhou, Junhu; Cao, Xinyu; Cen, Kefa

    2003-07-01

    The static distribution characteristic of fluoride in the combustion products of coal was studied by ashing procedure of coal, and the dynamic distribution characteristics of fluorine in the combustion products of coal in pulverized-coal-fired boiler and layer-burning boiler were investigated. Experimental results identified that fluorine in coal belong to volatile elements, fluorine in fly ash and bottom ash were non-rich. About 94.5% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in pulverized-coal-fired boiler, and about 80% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in layer-burning boiler. 55%-60% of the fluorine in fly ash of pulverized-coal-fired boiler were distributed in fly ash particles with a diameter of 74 microns-104 microns.

  15. Process for changing caking coals to noncaking coals

    DOEpatents

    Beeson, Justin L.

    1980-01-01

    Caking coals are treated in a slurry including alkaline earth metal hydroxides at moderate pressures and temperatures in air to form noncaking carbonaceous material. Hydroxides such as calcium hydroxide, magnesium hydroxide or barium hydroxide are contemplated for slurrying with the coal to interact with the agglomerating constituents. The slurry is subsequently dewatered and dried in air at atmospheric pressure to produce a nonagglomerating carbonaceous material that can be conveniently handled in various coal conversion and combustion processes.

  16. Ash formation under pressurized pulverized coal combustion conditions

    NASA Astrophysics Data System (ADS)

    Davila Latorre, Aura Cecilia

    Coal combustion is a source of inorganic particulate matter (ash), which can deposit in boilers and also be emitted into the atmosphere becoming part of ambient fine particulate matter (PM 2.5). In order to decrease coal combustion emissions per unit of power produced, higher efficiency systems have been proposed, including systems operating at elevated pressures. These new operating conditions will affect pollutant formation mechanisms, particularly those associated with the conversion of mineral matter to ash. Ash particle formation mechanisms are particularly sensitive to changes in pressure as they are related to the structure of coal char particles at early stages of combustion. To assess the importance of pressure on ash particle formation, pyrolyzed chars and ash particles from pressurized pulverized combustion of two bituminous and one subbituminous U.S. coals at operating pressures up to 30 atm were studied. Pressure changes the distribution of char particle types, changing the spatial distribution of the minerals during the combustion process and therefore affecting particle formation mechanisms. Chars were examined by Scanning Electron Microscopy (SEM) and classified into two different types (cenospheric and solid) depending on porosity and wall thickness. A correlation for estimating the amount of these cenospheric char particles was then proposed for bituminous coals based on the operating conditions and coal maceral analysis. The ash particle size distribution of the coals combusted at different operating pressures was measured using Computer Controlled Scanning Electron Microscopy (CCSEM). The results of the char characterization and ash particle size distribution measurements were then incorporated into an ash particle formation algorithm that was proposed and implemented. The model predicts ash particle size and composition distributions at elevated pressures under conditions of complete char burnout. Ash predictions were calculated by first

  17. Method for reducing NOx during combustion of coal in a burner

    DOEpatents

    Zhou, Bing; Parasher, Sukesh; Hare, Jeffrey J.; Harding, N. Stanley; Black, Stephanie E.; Johnson, Kenneth R.

    2008-04-15

    An organically complexed nanocatalyst composition is applied to or mixed with coal prior to or upon introducing the coal into a coal burner in order to catalyze the removal of coal nitrogen from the coal and its conversion into nitrogen gas prior to combustion of the coal. This process leads to reduced NOx production during coal combustion. The nanocatalyst compositions include a nanoparticle catalyst that is made using a dispersing agent that can bond with the catalyst atoms. The dispersing agent forms stable, dispersed, nano-sized catalyst particles. The catalyst composition can be formed as a stable suspension to facilitate storage, transportation and application of the catalyst nanoparticles to a coal material. The catalyst composition can be applied before or after pulverizing the coal material or it may be injected directly into the coal burner together with pulverized coal.

  18. Radiation properties of coal combustion products

    SciTech Connect

    Im, K.H.; Ahluwalia, R.K.

    1990-11-01

    An assessment is made of the experimental data and the theoretical bases for determining the absorption and scattering coefficients of the coal products of combustion. Particular attention is devoted to the complex refractive indices for char and ash. A dispersion relation is developed from sparse extinction data that can be used to estimate the optical constants of char. Considerable uncertainty and scatter is found in the literature data on ash optical constants and is attributed to variability in ash composition, lack of experimental rigor and limitations in the data reduction procedures. A correlation is presented for estimating the complex refractive indices of ash as a function of its mineral composition. A parametric study is conducted to elucidate the role of char, soot and ash particulates in determining the radiation properties of coal flames. The effects of combustion particulates are discussed in terms of the modification of the band structure of gas radiation to a luminous spectrum, introduction of scattering in radiation transport, particle size distribution, particle loading and particle composition. The results are interpreted as possible effects of coal beneficiation, coal micronization and flyash composition on heat transfer to the water walls of a coal furnace. 19 refs., 13 figs., 10 tabs.

  19. The effect of biomass on pollutant emission and burnout in co-combustion with coal

    SciTech Connect

    Kruczek, H.; Raczka, P.; Tatarek, A.

    2006-08-15

    This paper presents experimental and numerical results on the co-combustion of different types of biomass with hard and brown coal. The main aim of this work was to assess the impact of the cocombustion of biomass in brown and hard coal-fired systems on the combustion process itself and on the level of pollutant formation and its dependence on combustion temperature stoichiometry. The experimental results obtained have shown that in general biomass addition leads to decreased NO and SO{sub 2} emissions, except with the hard coal Bogdanka. In addition, the biomass has a beneficial effect on the burnout of the coal/biomass mixture. To help to account for this effect, the behaviour of coal and biomass, the coal/biomass mixture and of fuel-N was studied by thermal analysis, in nitrogen and in air. The results obtained have shown that gas phase interactions are dominant in the combustion of biomass/coal mixtures.

  20. Coal combustion science. Quarterly progress report, July--September 1994

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H.; Yang, N.Y.C.

    1995-09-01

    This document is a quarterly status report of the Coal Combustion Science Project that is being conducted at the Combustion Research Facility, Sandia National Laboratories, Livermore, California. The information reported is for the period July-September 1994. The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project.

  1. Mercury emissions and species during combustion of coal and waste

    SciTech Connect

    Hong Yao; Guangqian Luo; Minghou Xu; Tamotsu Kameshima; Ichiro Naruse

    2006-10-15

    The behaviors of mercury evolution for three types of coal and three types of dried sewage sludge are studied using a thermogravimetric (TG) analyzer. The mercury speciations in the flue gas from coal and sludge combustion are also analyzed by implementing a horizontal electrically heated tube furnace. Furthermore, the kinetic calculations of mercury oxidizing processes are carried out using the software package CHEMKIN in order to interpret the homogeneous mechanism of mercury oxidization. The results obtained show that the sulfur content in the sludge inhibits the evolution of mercury at low temperature if the Cl concentration is high enough. Chlorine enhances mercury evolution in the coal combustion, whereas there is no relationship when the Cl concentration is high. Fixed carbon content plays a role in depression of the mercury evolution. Formation of oxidized mercury (HgCl{sub 2}) does not relate to the chlorine concentration in the raw coal and sludge. Whereas the ash and sulfur content in the sludge affects the Hg oxidization, kinetic calculations show that HgCl, Cl{sub 2}, and HOCl formation is important in producing the oxidized mercury during combustion of coal and sludge at 873 K. A suitable temperature for Hg oxidization when Cl{sub 2} is the oxidization resource is 700-1200 K. 32 refs., 10 figs., 5 tabs.

  2. Development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January--March 1994

    SciTech Connect

    Not Available

    1994-04-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system, controls, and then test the complete system in order to evaluate its potential marketability. The past quarter began with a two-day test performed in January to determine the cause of pulsations in the batch feed system observed during pilot-scale testing of surrogate TSCA incinerator ash performed in December of 1993. Two different batch feedstocks were used during this test: flyash and cullet. The cause of the pulsations was traced to a worn part in the feeder located at the bottom of the batch feed tank. The problem was corrected by replacing the wom part with the corresponding part on the existing coal feed tank. A new feeder for the existing coal tank, which had previously been ordered as part of the new coal handling system, was procured and installed. The data from the pilot-scale tests performed on surrogate TSCA incinerator ash during December of 1993 was collected and analyzed. All of the glass produced during the test passed both the Toxicity characteristics Leach Procedure (TCLP) and the Product Consistency Test (PCT) by approximately two orders of magnitude.

  3. EPRI's coal combustion product use research

    SciTech Connect

    Ladwig, K.

    2008-07-01

    For more than 20 years, EPRI's Coal Combustion Product Use Program has been a leader in providing research to demonstrate the value of using coal combustion products (CCPs) in construction and manufacturing. Work is concentrated on large-volume uses, increasing use in traditional applications, uses in light of changes in CCP quality resulting form increased and new air emissions controls for nitrogen oxides, sulfur oxides and mercury. Currently, EPRI is investigating opportunities for using higher volumes of Class C ash in concrete; approaches for ensuring that mercury controls do not adversely affect the use of CCPs; agricultural uses for products from flue gas desulfurization; possible markets for spray dryer absorber byproducts; and issues involved with the presence of ammonia in ash. Some recent results and future work is described in this article. 4 photos.

  4. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

    NASA Astrophysics Data System (ADS)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

    2013-12-01

    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  5. COAL COMBUSTION PRODUCTS EXTENSION PROGRAM

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2005-05-15

    The primary objective of the CCP Extension Program is to promote the responsible uses of Ohio CCPs that are technically sound, environmentally safe, and commercially competitive. A secondary objective is to assist other CCP generating states (particularly neighboring states) in establishing CCP use programs within their states. The goal of the CCP extension program at OSU is to work with CCP stakeholders to increase the overall CCP state utilization rate to more than 30% by the year 2005. The program aims to increase FGD utilization for Ohio to more than 20% by the year 2005. The increased utilization rates are expected to be achieved through increased use of CCPs for highway, mine reclamation, agricultural, manufacturing, and other civil engineering uses. In order to accomplish these objectives and goals, the highly successful CCP pilot extension program previously in place at the university has been expanded and adopted by the university as a part of its outreach and engagement mission. The extension program is an innovative technology transfer program with multiple sponsors. The program is a collaborative effort between The Ohio State University (College of Engineering and University Extension Service), United States Department of Energy's National Energy Technology Laboratory, Ohio Department of Development's Coal Development Office, and trade associations such as the American Coal Ash Association as well as the Midwest Coal Ash Association. Industry co-sponsors include American Electric Power, Dravo Lime Company, and ISG Resources. Implementation of the proposed project results in both direct and indirect as well as societal benefits. These benefits include (1) increased utilization of CCPs instead of landfilling, (2) development of proper construction and installation procedures, (3) education of regulators, specification-writers, designers, construction contractors, and the public, (4) emphasis on recycling and decrease in the need for landfill space, (5

  6. Coal Combustion Products Extension Program

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2004-12-31

    The primary objective of the CCP Extension Program is to promote the responsible uses of Ohio CCPs that are technically sound, environmentally safe, and commercially competitive. A secondary objective is to assist other CCP generating states (particularly neighboring states) in establishing CCP use programs within their states. The goal of the CCP extension program at OSU is to work with CCP stakeholders to increase the overall CCP state utilization rate to more than 30% by the year 2005. The program aims to increase FGD utilization for Ohio to more than 20% by the year 2005. The increased utilization rates are expected to be achieved through increased use of CCPs for highway, mine reclamation, agricultural, manufacturing, and other civil engineering uses. In order to accomplish these objectives and goals, the highly successful CCP pilot extension program previously in place at the university has been expanded and adopted by the university as a part of its outreach and engagement mission. The extension program is an innovative technology transfer program with multiple sponsors. The program is a collaborative effort between The Ohio State University (College of Engineering and University Extension Service), United States Department of Energy's National Energy Technology Laboratory, Ohio Department of Development's Coal Development Office, and trade associations such as the American Coal Ash Association as well as the Midwest Coal Ash Association. Industry co-sponsors include American Electric Power, Dravo Lime Company, and ISG Resources. Implementation of the proposed project results in both direct and indirect as well as societal benefits. These benefits include (1) increased utilization of CCPs instead of landfilling, (2) development of proper construction and installation procedures, (3) education of regulators, specification-writers, designers, construction contractors, and the public, (4) emphasis on recycling and decrease in the need for landfill space, (5

  7. Coal Combustion Products Extension Program

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2003-12-31

    The primary objective of the CCP Extension Program is to promote the responsible uses of Ohio CCPs that are technically sound, environmentally safe, and commercially competitive. A secondary objective is to assist other CCP generating states (particularly neighboring states) in establishing CCP use programs within their states. The goal of the CCP extension program at OSU is to work with CCP stakeholders to increase the overall CCP state utilization rate to more than 30% by the year 2005. The program aims to increase FGD utilization for Ohio to more than 20% by the year 2005. The increased utilization rates are expected to be achieved through increased use of CCPs for highway, mine reclamation, agricultural, manufacturing, and other civil engineering uses. In order to accomplish these objectives and goals, the highly successful CCP pilot extension program previously in place at the university has been expanded and adopted by the university as a part of its outreach and engagement mission. The extension program is an innovative technology transfer program with multiple sponsors. The program is a collaborative effort between The Ohio State University (College of Engineering and University Extension Service), United States Department of Energy's National Energy Technology Laboratory, Ohio Department of Development's Coal Development Office, and trade associations such as the American Coal Ash Association as well as the Midwest Coal Ash Association. Industry co-sponsors include American Electric Power, Dravo Lime Company, and ISG Resources. Implementation of the proposed project results in both direct and indirect as well as societal benefits. These benefits include (1) increased utilization of CCPs instead of landfilling, (2) development of proper construction and installation procedures, (3) education of regulators, specification-writers, designers, construction contractors, and the public, (4) emphasis on recycling and decrease in the need for landfill space, (5

  8. Enhanced Combustion Low NOx Pulverized Coal Burner

    SciTech Connect

    Ray Chamberland; Aku Raino; David Towle

    2006-09-30

    For more than two decades, ALSTOM Power Inc. (ALSTOM) has developed a range of low cost, in-furnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes ALSTOM's internally developed TFS 2000 firing system, and various enhancements to it developed in concert with the U.S. Department of Energy (DOE). As of 2004, more than 200 units representing approximately 75,000 MWe of domestic coal fired capacity have been retrofit with ALSTOM low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coals to 0.10 lb/MMBtu for subbituminous coals, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing (retrofit) boiler equipment. If enacted, proposed Clear Skies legislation will, by 2008, require an average, effective, domestic NOx emissions rate of 0.16 lb/MMBtu, which number will be reduced to 0.13 lb/MMBtu by 2018. Such levels represent a 60% and 67% reduction, respectively, from the effective 2000 level of 0.40 lb/MMBtu. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. In light of these needs, ALSTOM, in cooperation with the DOE, is developing an enhanced combustion, low NOx pulverized coal burner which, when integrated with ALSTOM's state-of-the-art, globally air staged low NOx firing systems, will provide a means to achieve less than 0.15 lb/MMBtu NOx at less than 3/4 the cost of an SCR with low to no impact on balance of plant issues when firing a high volatile bituminous coal. Such coals can be more economic to fire than subbituminous or Powder River Basin (PRB) coals, but are more problematic from a NOx control standpoint as existing

  9. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    SciTech Connect

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  10. Catalytic combustion of coal-derived liquids

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  11. Plasma Torch for Plasma Ignition and Combustion of Coal

    NASA Astrophysics Data System (ADS)

    Ustimenko, Alexandr; Messerle, Vladimir

    2015-09-01

    Plasma-fuel systems (PFS) have been developed to improve coal combustion efficiency. PFS is a pulverized coal burner equipped with arc plasma torch producing high temperature air stream of 4000 - 6000 K. Plasma activation of coal at the PFS increases the coal reactivity and provides more effective ignition and ecologically friendly incineration of low-rank coal. The main and crucial element of PFS is plasma torch. Simplicity and reliability of the industrial arc plasma torches using cylindrical copper cathode and air as plasma forming gas predestined their application at heat and power engineering for plasma aided coal combustion. Life time of these plasma torches electrodes is critical and usually limited to 200 hours. Considered in this report direct current arc plasma torch has the cathode life significantly exceeded 1000 hours. To ensure the electrodes long life the process of hydrocarbon gas dissociation in the electric arc discharge is used. In accordance to this method atoms and ions of carbon from near-electrode plasma deposit on the active surface of the electrodes and form electrode carbon condensate which operates as ``actual'' electrode. Complex physicochemical investigation showed that deposit consists of nanocarbon material.

  12. Influence of sulfur in coals on char morphology and combustion

    SciTech Connect

    Marsh, H.

    1991-01-01

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  13. Coal liquefaction process

    SciTech Connect

    Gorbaty, M.L.; Long, R.B.; Schlosberg, R.H.

    1981-02-24

    An integrated coal pretreatment, liquefaction and gasification process is provided in which particulate coal is contacted with a vapor phase hydrogen donor solvent to swell the coal particles. The swollen coal particles are subjected to coal liquefaction conditions at relatively low temperatures. The solid residue of the coal liquefaction stage is subjected to pyrolysis conditions at relatively high temperatures to produce an additional amount of hydrocarbonaceous oil. The solid residue of the pyrolysis stage is gasified by treatment with steam and a molecular oxygen containing gas to produce a hydrogen-containing gas.

  14. Development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January 1993--March 1993

    SciTech Connect

    Not Available

    1993-04-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent performing the initial industrial proof-of-concept test and installing and integrating the Wet Electrostatic Precipitator (WESP). The other system modifications are well underway with the designs of the modifications to the batch/coal feed system being completed. A Purchase Order has been issued to a material conveying equipment vendor for the purchase of the batch/coal feeding equipment. The delivery and installation of the material conveying equipment is expected to occur in July and early August. The commercialization planning is continuing with the completion of a draft Business Plan. This plan is currently undergoing internal review, and will be submitted to Dawnbreaker, a DOE contracted small business consulting firm, for review.

  15. Burning of suspended coal-water slurry droplet with oil as combustion additive. Final report

    SciTech Connect

    Yao, S.C.

    1984-10-01

    The combustion of single coal-water slurry droplet with oil as combustion additive (CWOM) has been studied. In this study, the droplet is suspended on a fine quartz fiber and is exposed to the hot combustion product of propane (C/sub 3/H/sub 8/) and air. The results are documented in a movie series. The combustion of CWOM with various combinations of concentrations are compared with that of coal-water slurry and water-oil mixture droplets. The combustion of coal-water slurry is enhanced significantly due to the presence of emulsified kerosene. The enhancement is also dependent upon the mixing procedure during preparation of CWOM. The presence of emulsified kerosene induces local boil-off and combustion that coal particles are splashed as fire works during the early evaporation stage of droplet heat-up. After particle splashing, blow-holes appear on the droplet surface. The popcorn and swelling phenomena usually occurred in coal-water-slurry combustion is greatly reduced. Significant combustion enhancement occurs with the use of kerosene in an amount of about 15 percent of the overall CWOM. This process of using kerosene as combustion additive may provide obvious advantage for the combustion of bituminous coal-water slurry. 4 references, 6 figures.

  16. Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-Btu coal gasifier

    SciTech Connect

    Benson, J.M.; Hanson, R.L.; Royer, R.E.; Clark, C.R.; Henderson, R.F.

    1984-04-01

    The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mugtagenicity of 6.7 reverants/..mu..g (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/..mu..g), a significant overall reduction in mutagenicity was achieved (to 2200 reverants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/..mu..g (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the aerosolized tars emitted in fugitive emissions. Health risks to general population resulting from exposure to gas combustion products are expected to be minimal. 28 references.

  17. STRUCTURE BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2001-06-15

    This report is part on the ongoing effort at Brown University and Ohio State University to develop structure based models of coal combustion. A very fundamental approach is taken to the description of coal chars and their reaction processes, and the results are therefore expected to have broad applicability to the spectrum of carbon materials of interest in energy technologies. This quarter, the project was in a period no-cost extension and discussions were held about the end phase of the project and possible continuations. The technical tasks were essentially dormant this period, but presentations of results were made, and plans were formulated for renewed activity in the fiscal year 2001.

  18. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles What determines their composition Whether or not particles deposit How combustion conditions, including reactor size, affect these processes remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

  19. Continuous coal processing method

    NASA Technical Reports Server (NTRS)

    Ryason, P. R. (Inventor)

    1980-01-01

    A coal pump is provided in which solid coal is heated in the barrel of an extruder under pressure to a temperature at which the coal assumes plastic properties. The coal is continuously extruded, without static zones, using, for example, screw extrusion preferably without venting through a reduced diameter die to form a dispersed spray. As a result, the dispersed coal may be continuously injected into vessels or combustors at any pressure up to the maximum pressure developed in the extrusion device. The coal may be premixed with other materials such as desulfurization aids or reducible metal ores so that reactions occur, during or after conversion to its plastic state. Alternatively, the coal may be processed and caused to react after extrusion, through the die, with, for example, liquid oxidizers, whereby a coal reactor is provided.

  20. Coal combustion: Effect of process conditions on char reactivity. Ninth quarterly technical report, September 1, 1992--December 1, 1993

    SciTech Connect

    Zygourakis, K.

    1993-12-31

    Our efforts during the past quarter focused on the development of an image processing technique for characterizing the macropore structure of chars produced from Illinois No. 6 coal. Pyrolysis experiments were carried out in a microscope-stage reactor in inert and reacting atmospheres and at various pyrolysis heating rates. Particles from several pyrolysis runs were embedded in an epoxy resin block and polished sections . were prepared. Digital images of char particle cross-sections were acquired and analyzed to measure the structural properties of the chars. The macropore analysis procedure is presented here in detail. Future reports will present the data showing the effects of pyrolysis conditions on the macropore structure of Illinois No. 6 chars.

  1. Simultaneous combustion of waste plastics with coal for pulverized coal injection application

    SciTech Connect

    Sushil Gupta; Veena Sahajwalla; Jacob Wood

    2006-12-15

    A bench-scale study was conducted to investigate the effect of simultaneous cofiring of waste plastic with coal on the combustion behavior of coals for PCI (pulverized coal injection) application in a blast furnace. Two Australian coals, premixed with low- and high-density polyethylene, were combusted in a drop tube furnace at 1473 K under a range of combustion conditions. In all the tested conditions, most of the coal blends including up to 30% plastic indicated similar or marginally higher combustion efficiency compared to those of the constituent coals even though plastics were not completely combusted. In a size range up to 600 {mu}m, the combustion efficiency of coal and polyethylene blends was found be independent of the particle size of plastic used. Both linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE) are shown to display similar influence on the combustion efficiency of coal blends. The effect of plastic appeared to display greater improvement on the combustion efficiency of low volatile coal compared to that of a high volatile coal blend. The study further suggested that the effect of oxygen levels of the injected air in improving the combustion efficiency of a coal-plastic blend could be more effective under fuel rich conditions. The study demonstrates that waste plastic can be successfully coinjected with PCI without having any adverse effect on the combustion efficiency particularly under the tested conditions. 22 refs., 12 figs., 2 tabs.

  2. Coal combustion: Effect of process conditions on char reactivity. Quarterly technical report, September 1, 1991--December 1, 1991

    SciTech Connect

    Zygourakis, K.

    1991-12-31

    The project will quantify the effect of the following pyrolysis conditions on the macropore structure and on the subsequent reactivity of chars: (a) pyrolysis heating rate; (b) final heat treatment temperature (HTT); (c) duration of heat treatment at HTT (or soak time); (d) pyrolysis atmosphere (N{sub 2} or O{sub 2}/N{sub 2} mixtures); (e) coal particle size (100 {endash} 1000 {mu}m in diameter); (f) sulfur-capturing additives (limestone); and (g) coal rank. Pyrolysis experiments will be carried out for three coals from the Argonne collection: (1) a high-volatile bituminous coal with high ash content (Illinois {number_sign}6), (2) a bituminous coal with low ash content (Utah Blind Canyon) and (3) a lower rank subbituminous coal (Wyodak-Anderson seam).

  3. Coal combustion science: Task 1, Coal char combustion: Task 2, Fate of mineral matter. Quarterly progress report, July--September 1993

    SciTech Connect

    Hardesty, D.R.; Hurt, R.H.; Davis, K.A.; Baxter, L.L.

    1994-07-01

    Progress reports are presented for the following tasks: (1) kinetics and mechanisms of pulverized coal char combustion and (2) fate of inorganic material during coal combustion. The objective of Task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. In Sandia`s Coal Combustion Laboratory (CCL), optical techniques are used to obtain high-resolution images of individual burning coal char particles and to measure, in situ, their temperatures, sizes, and velocities. Detailed models of combustion transport processes are then used to determine kinetic parameters describing the combustion behavior as a function of coal type and combustion environment. Partially reacted char particles are also sampled and characterized with advanced materials diagnostics to understand the critical physical and chemical transformations that influence reaction rates and burnout times. The ultimate goal of the task is the establishment of a data base of the high temperature reactivities of chars from strategic US coals, from which important trends may be identified and predictive capabilities developed. The overall objectives for task 2 are: (1) to complete experimental and theoretical investigation of ash release mechanisms; (2) to complete experimental work on char fragmentation; (3) to establish the extent of coal (as opposed to char) fragmentation as a function of coal type and particle size; (4) to develop diagnostic capabilities for in situ, real-time, qualitative indications of surface species composition during ash deposition, with work continuing into FY94; (5) to develop diagnostic capabilities for in situ, real-time qualitative detection of inorganic vapor concentrations; and (6) to conduct a literature survey on the current state of understanding of ash deposition, with work continuing into FY94.

  4. Kinetics of Coal Char Combustion in Oxygen-Enriched Environment

    NASA Astrophysics Data System (ADS)

    Czakiert, T.; Nowak, W.

    The influence of oxygen-enriched gaseous atmosphere on coal char combustion was studied. Two different coals, i.e. lignite and bituminous coal, were used as a basic fuel and the reacting gases of oxygen & CO2 were used to simulate flue gas recirculation. Moreover, a broad range of in-furnace conditions, i.e. five temperatures of 873, 973, 1073, 1173, 1273K and five oxygen concentrations of 20, 40, 60, 80, 100%vol., was investigated. Thermogravimetric method of measurement was employed to obtain the processing data on fuel conversion rate under foregoing investigated conditions. For further calculations, simplified Shrinking-Core Model was introduced. Finally, fundamental kinetic parameters, i.e. pre-exponential factor, activation energy and reaction order, were established and then on the basis of their values reaction-controlling regime for coal char combustion in oxygen-enriched environment was predicted. The investigations, financially supported by Polish Government, are a part of Framework Project "Supercritical Coal-fired Power Units".

  5. Near-extinction and final burnout in coal combustion

    SciTech Connect

    Hurt, R.H.; Davis, K.A.

    1994-02-01

    The late stages of char combustion have a special technological significance, as carbon conversions of 99% or greater are typically required for the economic operation of pulverized coal fired boilers. In the present article, two independent optical techniques are used to investigate near-extinction and final burnout phenomenas. Captive particle image sequences, combined with in situ optical measurements on entrained particles, provide dramatic illustration of the asymptotic nature of the char burnout process. Single particle combustion to complete burnout is seen to comprise two distinct stages: (1) a rapid high-temperature combustion stage, consuming about 70% of the char carbon and ending with near-extinction of the heterogeneous reactions due to a loss of global particle reactivity, and (2) a final burnout stage occurring slowly at lower temperatures. For particles containing mineral matter, the second stage can be further subdivided into: (2a) late char combustion, which begins after the near-extinction event, and converts carbon-rich particles to mixed particle types at a lower temperature and a slower rate; and (2b) decarburization of ash -- the removal of residual carbon inclusions from inorganic (ash) frameworks in the very late stages of combustion. This latter process can be extremely slow, requiring over an order of magnitude more time than the primary rapid combustion stage. For particles with very little ash, the loss of global reactivity leading to early near-extinction is clearly related to changes in the carbonaceous char matrix, which evolves over the course of combustion. Current global kinetic models used for the prediction of char combustion rates and carbon burnout in boilers do not predict the asymptotic nature of char combustion. More realistic models accounting for the evolution of char structure are needed to make accurate predictions in the range of industrial interest.

  6. Coal liquefaction quenching process

    DOEpatents

    Thorogood, Robert M.; Yeh, Chung-Liang; Donath, Ernest E.

    1983-01-01

    There is described an improved coal liquefaction quenching process which prevents the formation of coke with a minimum reduction of thermal efficiency of the coal liquefaction process. In the process, the rapid cooling of the liquid/solid products of the coal liquefaction reaction is performed without the cooling of the associated vapor stream to thereby prevent formation of coke and the occurrence of retrograde reactions. The rapid cooling is achieved by recycling a subcooled portion of the liquid/solid mixture to the lower section of a phase separator that separates the vapor from the liquid/solid products leaving the coal reactor.

  7. Characterization and comparative study of coal combustion residues from a primary and additional flue gas secondary desulfurization process

    SciTech Connect

    Gomes, S.; Francois, M.; Evrard, O.; Pellissier, C.

    1998-11-01

    An extensive characterization and comparative study was done on two flue gas desulfurization (FGD) residues derived from the same coal. LR residues (originated from Loire/Rhone in the south of Lyon, France) are obtained after a primary desulfurization process (SO{sub 2} is trapped by reaction with CaO at a temperature of about 1100 C), and LM residues (originating from La Maxe, near Metz in the east of France) are obtained after an additional secondary desulfurization process (SO{sub 2} is removed further by reaction with Ca(OH){sub 2} at a temperature of about 120 C). Various and complementary investigation methods were used to determine their chemical, physical, and mineralogical properties: x-ray fluorescence and diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetry analysis, granulometric distribution, pycnometric density, BET specific surface area and pH, conductivity measurements, and chemical analysis of their insoluble fraction. The FGD residues contain basically two main components: a silico-aluminous fly ash part and calcic FGD phases. In the LR residues the two components can be considered as independent, whereas they are linked in the LM residues because chemical reactions have occurred, leading to the formation of silico-calcic gel CSH, hydrated aluminate AFm, and AFt phases.

  8. Ignition and combustion of coal particles

    SciTech Connect

    Gomez, C.O.; Vastola, F.J.

    1983-09-01

    A subbituminous coal was used in this study. Particles from the 850 to 1000 ..mu.. sieve fraction were injected into a reaction furnace swept with air at temperature levels of 928/sup 0/, 980/sup 0/, 1076/sup 0/, 1118/sup 0/ and 1273/sup 0/K. The experimental technique, based upon the simultaneous measurement of the carbon monoxide, carbon dioxide, and the intensity of the light generated during the combustion, provides quantitative information about the ignition and the subsequent burn-off of the residual particle. Homogeneous ignition is detected at temperatures of 1076/sup 0/K and higher. The apparatus designed provides the special characteristics required in this study, and the transition between the ignition mechanisms is achieved within the range of operation conditions for this particular coal. The ignition mechanism is determined not only from the measurement of light intensity during the combustion, but also from the gas evolution curves. The results show the convenience of using these complementary techniques for the measurement of the ignition mechanism. 4 figures, 2 tables.

  9. TOXIC SUBSTANCES FROM COAL COMBUSTION-A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; F. Huggins; G.P. Huffman; N. Shah; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F. Sarofim; S. Swenson; J.S. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowski; J.J. Helble; R. Mamani-Paco; R. Sterling; G. Dunham; S. Miller

    2001-06-30

    speciation of mercury captured on low-temperature sorbents from combustion flue gases and developed XAFS parameters for such analyses. We demonstrated that all mercury sorption processes appeared to involve chemisorption rather than physisorption. This work aimed to develop a model that predicts the vaporization of metals during coal combustion and to incorporate this model into the existing Engineering Model for Ash Formation (EMAF). The model is based on theoretical analysis for metal vaporization, experimental data and data correlations. The existing program, EMAF, was substantially modified to accommodate the vaporization sub-model.

  10. Energy recycling by co-combustion of coal and recovered paint solids from automobile paint operations.

    PubMed

    Suriyawong, Achariya; Magee, Rogan; Peebles, Ken; Biswas, Pratim

    2009-05-01

    During the past decade, there has been substantial interest in recovering energy from many unwanted byproducts from industries and municipalities. Co-combustion of these products with coal seems to be the most cost-effective approach. The combustion process typically results in emissions of pollutants, especially fine particles and trace elements. This paper presents the results of an experimental study of particulate emission and the fate of 13 trace elements (arsenic [As], barium [Ba], cadmium [Cd], chromium [Cr], copper [Cu], cobalt [Co], manganese [Mn], molybdenum [Mo], nickel [Ni], lead [Pb], mercury [Hg], vanadium [V], and zinc [Zn]) during combustion tests of recovered paint solids (RPS) and coal. The emissions from combustions of coal or RPS alone were compared with those of co-combustion of RPS with subbituminous coal. The distribution/partitioning of these toxic elements between a coarse-mode ash (particle diameter [dp] > 0.5 microm), a submicrometer-mode ash (dp < 0.5 microm), and flue gases was also evaluated. Submicrometer particles generated by combustion of RPS alone were lower in concentration and smaller in size than that from combustion of coal. However, co-combustion of RPS and coal increased the formation of submicrometer-sized particles because of the higher reducing environment in the vicinity of burning particles and the higher volatile chlorine species. Hg was completely volatilized in all cases; however, the fraction in the oxidized state increased with co-combustion. Most trace elements, except Zn, were retained in ash during combustion of RPS alone. Mo was mostly retained in all samples. The behavior of elements, except Mn and Mo, varied depending on the fuel samples. As, Ba, Cr, Co, Cu, and Pb were vaporized to a greater extent from cocombustion of RPS and coal than from combustion of either fuel. Evidence of the enrichment of certain toxic elements in submicrometer particles has also been observed for As, Cd, Cr, Cu, and Ni during co-combustion

  11. Investigation of formation of nitrogen compounds in coal combustion. Final report

    SciTech Connect

    Blair, D.W.; Crane, I.D.; Wendt, J.O.L.

    1983-10-01

    This is the final report on DOE contract number DE-AC21-80MC14061. It concerns the formation of nitrogen oxide from fuel-bound nitrogen during coal combustion. The work reported was divided into three tasks. They addressed problems of time-resolving pyrolysis rates of coal under simulated combustion conditions, the combustion of the tar that results from such pyrolysis, and theoretical modeling of the pyrolysis process. In all of these tasks, special attention was devoted to the fate of coal nitrogen. The first two tasks were performed by Exxon Research and Engineering Company. 49 references.

  12. Coal combustion: Effect of process conditions on char reactivity. Quarterly technical report, July 1, 1994--September 30, 1994

    SciTech Connect

    Zygourakis, K.

    1994-12-31

    The project will quantify the effect of the following pyrolysis conditions on the macropore structure and on the subsequent reactivity of chars: (a) pyrolysis heating rate; (b) final heat treatment temperature (HTT); (c) duration of heat treatment at HTT (or soak time); (d) pyrolysis atmosphere (N{sub 2} or O{sub 2}/N{sub 2} mixtures); (e) coal particle size (100-1,000 {mu}m in diameter); (f) sulfur-capturing additives (limestone); and (g) coal rank. Pyrolysis experiments will be carried out for three coals from the Argonne collection: (1) a high-volatile bituminous coal with high ash content (Illinois {number_sign}6), (2) a bituminous coal with low ash content (Utah Blind Canyon) and (3) a lower rank subbituminous coal (Wyodak-Anderson seam). A mathematical model was developed to study the thermal ignition of char particles. The model assumes a bimodal pores size distribution with small micropores (of the order of a few {angstrom}) and large micropores in the {mu}m size range. All the model parameters can be estimated using data obtained previously in our laboratory. We are currently testing this model to determine its validity and to investigate how char properties (porosity, particle size, macropore surface area, micropore radius) and operating conditions (temperature, oxygen concentration, flow rate) affect ignition phenomena.

  13. On the combustion of bituminous coal chars

    SciTech Connect

    Sahu, R.

    1988-01-01

    The chars were made by pyrolyzing size-graded PSOC 1451 coal particles in nitrogen at 1000-1600K. Sized char particles were then used in subsequent experiments. Low temperature reactivities of such cenospheric chars were measured at 800K in a TGA. The effects of initial coal size, char size, pyrolysis temperature, and oxygen concentration were investigated. Single particle combustion experiments were done in both air and 50 percent oxygen ambients at 1000-1500K wall temperatures in a drop-tube laminar-flow reactor. The ignition transients of single burning particles were explained using a simple thermal model. Char samples were also partially oxidized at 1200-1500K and then physically characterized using optical and electron microscopy, gas adsorption methods, and mercury porosimetry. Results of characterization were compared to those done at 800K. Single particle combustion was numerically modeled. At first, a continuum model for asymptotic shrinking-core combustion was developed using apparent reaction rate and temperature-dependent properties. Later, a more general continuum model was developed that treated the internal morphology of the particles more realistically, as inferred from experiments. The steady-state diffusion equation was solved inside the particle to determine its theoretical temperature-time history. Good agreement with experimental results was found. The model was extended to include the effect of nonlinear kinetics. A discrete model for a cenospheric char particle was also developed, in which spherical voids were randomly placed in a spherical particle. Connectivity of the internal pore structure was accounted for.

  14. Integrated coal liquefaction process

    DOEpatents

    Effron, Edward

    1978-01-01

    In a process for the liquefaction of coal in which coal liquids containing phenols and other oxygenated compounds are produced during the liquefaction step and later hydrogenated, oxygenated compounds are removed from at least part of the coal liquids in the naphtha and gas oil boiling range prior to the hydrogenation step and employed as a feed stream for the manufacture of a synthesis gas or for other purposes.

  15. Low-Btu coal-gasification-process design report for Combustion Engineering/Gulf States Utilities coal-gasification demonstration plant. [Natural gas or No. 2 fuel oil to natural gas or No. 2 fuel oil or low Btu gas

    SciTech Connect

    Andrus, H E; Rebula, E; Thibeault, P R; Koucky, R W

    1982-06-01

    This report describes a coal gasification demonstration plant that was designed to retrofit an existing steam boiler. The design uses Combustion Engineering's air blown, atmospheric pressure, entrained flow coal gasification process to produce low-Btu gas and steam for Gulf States Utilities Nelson No. 3 boiler which is rated at a nominal 150 MW of electrical power. Following the retrofit, the boiler, originally designed to fire natural gas or No. 2 oil, will be able to achieve full load power output on natural gas, No. 2 oil, or low-Btu gas. The gasifier and the boiler are integrated, in that the steam generated in the gasifier is combined with steam from the boiler to produce full load. The original contract called for a complete process and mechanical design of the gasification plant. However, the contract was curtailed after the process design was completed, but before the mechanical design was started. Based on the well defined process, but limited mechanical design, a preliminary cost estimate for the installation was completed.

  16. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYTEMS

    EPA Science Inventory

    The report describes the development of a vortex containment combustor (VCC) for coal combustion systems, designed to solve major problems facing the conversion of oil- and gas-fired boilers to coal (e.g., derating, inorganic impurities in coal, and excessive formation of NOx and...

  17. Coal liquefaction process

    SciTech Connect

    Long, R.B.; Gorbaty, M.L.; Schlosberg, R.H.

    1981-02-24

    In this integrated coal pretreatment, liquefaction, and gasification process, particulate coal is contacted with a vapor-phase hydrogen-donor solvent to swell the coal particles and then subjected to coal liquefaction at relatively low temperatures. The solid residue of the liquefaction stage undergoes pyrolysis at high temperatures to produce an additional amount of oil. The solid residue of the pyrolysis stage is then gasified by treatment with steam and a molecular-oxygen-containing gas to produce a hydrogen-containing gas.

  18. Coal liquefaction process

    DOEpatents

    Carr, Norman L.; Moon, William G.; Prudich, Michael E.

    1983-01-01

    A C.sub.5 -900.degree. F. (C.sub.5 -482.degree. C.) liquid yield greater than 50 weight percent MAF feed coal is obtained in a coal liquefaction process wherein a selected combination of higher hydrogen partial pressure, longer slurry residence time and increased recycle ash content of the feed slurry are controlled within defined ranges.

  19. [Coal fineness effect on primary particulate matter features during pulverized coal combustion].

    PubMed

    Lü, Jian-yi; Li, Ding-kai

    2007-09-01

    Three kinds of coal differed from fineness were burned in a laboratory-scale drop tube furnace for combustion test, and an 8-stage Andersen particle impactor was employed for sampling the primary particulate matter (PM), in order to study coal fineness effect on primary PM features during pulverized coal combustion. It has been shown that the finer the coal was, the finer the PM produced. PM, emission amount augmented with coal fineness decreased, and the amount of PM10 increased from 13 mg/g to 21 mg/g respectively generated by coarse coal and fine coal. The amount of PM2.5 increased from 2 mg/g to 8 mg/g at the same condition. Constituents and content in bulk ash varied little after three different fineness coal combustion, while the appearance of grading PM differed visibly. The value of R(EE) increased while the coal fineness deceased. The volatility of trace elements which were investigated was Pb > Cr > Zn > Cu > Ni in turn. The concentration of poisonous trace elements was higher which generated from fine coal combustion. The volatilization capacity was influenced little by coal fineness, but the volatilization extent was influenced differently by coal fineness. Fine coal combustion affects worse environment than coarse coal does. PMID:17990536

  20. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 6, July 1990--September 1990

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  1. Ignition/combustion processes

    NASA Technical Reports Server (NTRS)

    Pryor, D. E.

    1985-01-01

    The overall objectives for this initial technology are to generate an advanced, comprehensive combustion analytical code, and to verify the combustion flow dynamic predictions from this model with hot test experimental data.

  2. Apparatus for processing coal

    SciTech Connect

    Williams, R.M.

    1985-02-12

    Apparatus for processing coal to prevent the creation of extreme fines and to extract pyrites from the principal coal fractions in which there are two air circulating circuits having processing components which cooperate in their respective circuits to result initially in substantial extraction of fines in the first circuit while releasing principal granulated coal fractions and pyrites to the second circuit where specific gravity separation of the pyrites and principal coal fractions occur. The apparatus includes a source of drying heat added to the air moving in the circuits and delivered at the places where surface moisture drying is most effective. Furthermore, the apparatus is operated so as to reduce coal to a desired size without creating an excessive volume of extreme fines, to separate pyrites and hard to grind components by specific gravity in a region where fines are not present, and to use the extreme fines as a source of fuel to generate drying heat.

  3. Thermally induced structural changes in coal combustion

    SciTech Connect

    Flagan, R.C.; Gavalas, G.R.

    1992-01-01

    The effects of the temperature-time history during coal devolitization and oxidation on the physical properties and the reactivity of resulting char were studied experimentally for temperatures and residence times typical of pulverized combustion. Experiments were also carried out at somewhat lower temperatures and correspondingly longer residence times. An electrically heated laminar flow reactor was used to generate char and measure the rates of oxidation at gas temperatures about 1600K. Partially oxidized chars were extracted and characterized by gas adsorption and mercury porosimetry, optical and scanning electron microscopy, and oxidation in a thermogravimetric analysis system (TGA). A different series of experiments was conducted using a quadrople electrodynamic balance. Single particles were suspended electrodynamically and heated by an infrared laser in an inert or oxygen-containing atmosphere. During the laser heating, measurements were taken of particle mass, size/shape, and temperature.

  4. Investigation of the behavior of mercury compounds in coal combustion products

    SciTech Connect

    G.Ya. Gerasimov

    2005-07-15

    The main mechanisms of transformation of mercury compounds in coal combustion products in the region of high temperatures have been analyzed. A kinetic model of the process of gas-phase oxidation of metal mercury vapors is proposed. The features of the behavior of the investigated compounds in systems of cleaning combustion products from harmful impurities have been considered.

  5. Enhancement of pulverized coal combustion by plasma technology

    SciTech Connect

    Gorokhovski, M.A.; Jankoski, Z.; Lockwood, F.C.; Karpenko, E.I.; Messerle, V.E.; Ustimenko, A.B.

    2007-07-01

    Plasma-assisted pulverized coal combustion is a promising technology for thermal power plants (TPP). This article reports one- and three- dimensional numerical simulations, as well as laboratory and industrial measurements of coal combustion using a plasma-fuel system (PFS). The chemical kinetic and fluid mechanics involved in this technology are analysed. The results show that a PFS, can be used to promote early ignition and enhanced stabilization of a pulverized coal flame. It is shown that this technology, in addition to enhancing the combustion efficiency of the flame, reduces harmful emissions from power coals of all ranks (brown, bituminous, anthracite and their mixtures). Data summarising the experience of 27 pulverized coal boilers in 16 thermal power plants in several countries (Russia, Kazakhstan, Korea, Ukraine, Slovakia, Mongolia and China), embracing steam productivities from 75 to 670 tons per hour (TPH), are presented. Finally, the practical computation of the characteristics of the PFS, as function of coal properties, is discussed.

  6. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, M.N.B. ); Shah, N.; Huggins, F.E. Huffman, G.P. )

    1991-05-01

    Objectives of this project are: (1) define the partitioning of inorganic constituents associated with raw coal particles among products (including vapors, aerosols, and residual char/ash particles) formed under conditions representative of pulverized coal flames as a function of the specific (intrinsic and extrinsic) characteristics of the raw coal and the environment in which the transformations occur; and (2) characterize the resultant spectrum of products in detail; To elucidate and quantify the fundamental processes and by which transformations of the inorganic constituents occur; and To develop, based on the information required in the above, a tractable process'' model capable of predicting the significant features of the transformation process, most importantly, the nature and distribution of products. The work discussed herein highlights recent accomplishments: at the University of Kentucky (UK), in analyzing recently obtained XAFS data; at the Massachusetts Institute of Technology (MIT), in modeling the char fragmentation process, allowing for pore interactions to produce clustered pore arrangements; at MIT, in analyzing experiments with chars of varying porosity to quantify the effect on char fragmentation; at the University of Arizona (UA), in examining the behavior of alkali metals during combustion; at UA, in examining the capture of vaporized sodium by extraneous kaolinite additive; at PSI Technology Company (PSIT), in examining the transformations and stickiness of nepheline and kaolinite/montmorillonite mixtures, and conducting initial experiments with the SOAP and Loy Yang 1953 coals; and at PSIT, in continuing development of the engineering model for ash particle formation. 96 figs., 4 tabs.

  7. Experimental study on horizontal combustion technique for bitumite-moulded coal

    SciTech Connect

    Shao, Y.; Lu, C.; Cheng, S.; Deng, J.; Chen, Z.

    1994-12-31

    Through a lot of experiments, a new kind of stove using horizontal combustion technique for bitumite-moulded coal has been developed. Making use of this stove, studies have been made on the burning process of bitumite-moulded coal: distribution of temperature field in the stove, the regularities of evolution and combustion of volatile matter, the burning rate and efficiency of bitumite-moulded coal, characteristics of fire-sealing and sulfur-solidification. The results show that, with the technique, some achievements can be obtained in combustion of bitumite-moulded coal, such as lower pollution in that the flue gas opacity is below 0.5 R and dust concentration is below 90 mg/Nm{sup 3}. The stove`s combustion efficiency reaches 90%, sulfur fixing efficiency is 60%, and CO concentration is decreased by 40% compared with other traditional stoves. With so many advantages, the stove can be used extensively in civil stoves and smaller industrial boilers.

  8. Modeling of pulverized coal combustion in cement rotary kiln

    SciTech Connect

    Shijie Wang; Jidong Lu; Weijie Li; Jie Li; Zhijuan Hu

    2006-12-15

    In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rotary kiln were obtained by numerical simulation of a 3000 t/d rotary kiln with a four-channel burner. The predicted results indicated that the improved model accounts for the thermal enthalpy of the clinker formation process and can give more insight (such as fluid flow, temperature, etc,) from within the cement rotary kiln, which is a benefit to better understanding of combustion behavior and an improvement of burner and rotary kiln technology. 25 refs., 12 figs., 5 tabs.

  9. Combustion of volatile matter during the initial stages of coal combustion

    SciTech Connect

    Marlow, D.; Niksa, S.; Kruger, C.H.

    1990-08-01

    Both the secondary pyrolysis and combustion of the volatiles from a bituminous coal will be studied. Devolatilization and secondary pyrolysis experiments will be conducted in a novel flow reactor in which secondary pyrolysis of the volatiles occurs after devolatilization is complete. This allows unambiguous measurements of the yields from both processes. Measurements will be made for reactor temperatures from 1500 to 1700 K, and a nominal residence time of 200 msec. These conditions are typical of coal combustion. Yields of tar, soot, H{sub 2}, CO, CH{sub 4}, and C{sub 2} and C{sub 3} hydrocarbons will be determined as a function of reactor temperature. The yields will be reported as a function of the temperature of the reactor. The instrumentation for temperature measurements will be developed during future studies. Combustion studies will be conducted in a constant volume bomb, which will be designed and constructed for this study. Tar and soot will be removed before introducing the volatiles to the bomb, so that only the combustion of the light gas volatiles will be considered. The burning velocities of light gas volatiles will be determined both as functions of mixture stoichiometry and the temperature at which the volatiles are pyrolysed. 90 refs., 70 figs., 13 tabs.

  10. Coal Liquefaction Processes.

    ERIC Educational Resources Information Center

    Yen, T. F.

    1979-01-01

    Described is a graduate level engineering course offered at the University of Southern California on coal liquefaction processes. Lecture topics and course requirements are discussed. A 64-item bibliography of papers used in place of a textbook is included. (BT)

  11. Influence of combustion conditions and coal properties on physical properties of fly ash generated from pulverized coal combustion

    SciTech Connect

    Hiromi Shirai; Hirofumi Tsuji; Michitaka Ikeda; Toshinobu Kotsuji

    2009-07-15

    To develop combustion technology for upgrading the quality of fly ash, the influences of the coal properties, such as the size of pulverized coal particles and the two-stage combustion ratio during the combustion, on the fly ash properties were investigated using our test furnace. The particle size, density, specific surface area (obtained by the Blaine method), and shape of fly ash particles of seven types of coal were measured. It was confirmed that the size of pulverized coal particles affects the size of the ash particles. Regarding the coal properties, the fuel ratio affected the ash particle size distribution. The density and shape of the ash particles strongly depended on their ash size. Our results indicated that the shape of the ash particles and the concentration of unburned carbon affected the specific surface area. The influence of the two-stage combustion ratio was limited. 8 refs., 13 figs., 3 tabs.

  12. Coal liquefaction process

    DOEpatents

    Skinner, Ronald W.; Tao, John C.; Znaimer, Samuel

    1985-01-01

    This invention relates to an improved process for the production of liquid carbonaceous fuels and solvents from carbonaceous solid fuels, especially coal. The claimed improved process includes the hydrocracking of the light SRC mixed with a suitable hydrocracker solvent. The recycle of the resulting hydrocracked product, after separation and distillation, is used to produce a solvent for the hydrocracking of the light solvent refined coal.

  13. Coal liquefaction process

    DOEpatents

    Karr, Jr., Clarence

    1977-04-19

    An improved coal liquefaction process is provided which enables conversion of a coal-oil slurry to a synthetic crude refinable to produce larger yields of gasoline and diesel oil. The process is characterized by a two-step operation applied to the slurry prior to catalytic desulfurization and hydrogenation in which the slurry undergoes partial hydrogenation to crack and hydrogenate asphaltenes and the partially hydrogenated slurry is filtered to remove minerals prior to subsequent catalytic hydrogenation.

  14. An Integrated Model of Coal/Coke Combustion in a Blast Furnace

    NASA Astrophysics Data System (ADS)

    Shen, Y. S.; Guo, B. Y.; Yu, A. B.; Austin, P.; Zulli, P.

    2010-03-01

    A three-dimensional integrated mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance-blowpipe-tuyere-raceway-coke bed to simulate the operation of pulverized coal injection in an ironmaking blast furnace. The model integrates two parts: pulverized coal combustion model in the blowpipe-tuyere-raceway-coke bed and the coke combustion model in the coke bed. The model is validated against the measurements in terms of coal burnout and gas composition, respectively. The comprehensive in-furnace phenomena are simulated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. In addition, underlying mechanisms for the in-furnace phenomena are analyzed. The model provides a cost-effective tool for understanding and optimizing the in-furnace flow-thermo-chemical characteristics of the PCI process in full-scale blast furnaces.

  15. Carbon dioxide from coal combustion: Variation with rank of US coal

    USGS Publications Warehouse

    Quick, J.C.; Glick, D.C.

    2000-01-01

    Carbon dioxide from combustion of US coal systematically varies with ASTM rank indices, allowing the amount of CO2 produced per net unit of energy to be predicted for individual coals. No single predictive equation is applicable to all coals. Accordingly, we provide one equation for coals above high volatile bituminous rank and another for lower rank coals. When applied to public data for commercial coals from western US mines these equations show a 15% variation of kg CO2 (net GJ)-1. This range of variation suggests reduction of US CO2 emissions is possible by prudent selection of coal for combustion. Maceral and mineral content are shown to slightly affect CO2 emissions from US coal. We also suggest that CO2 emissions increased between 6 and 8% in instances where Midwestern US power plants stopped burning local, high-sulfur bituminous coal and started burning low-sulfur, subbituminous C rank coal from the western US.

  16. Hardened, environmentally disposable composite granules of coal cleaning refuse, coal combustion waste, and other wastes, and method preparing the same

    DOEpatents

    Burnet, G.; Gokhale, A.J.

    1990-07-10

    A hardened, environmentally inert and disposable composite granule of coal cleaning refuse and coal combustion waste and method for producing the same are disclosed, wherein the coal combustion waste is first granulated. The coal cleaning refuse is pulverized into fine particles and is then bound, as an outer layer, to the granulated coal combustion waste granules. This combination is then combusted and sintered. After cooling, the combination results in hardened, environmentally inert and disposable composite granules having cores of coal combustion waste, and outer shells of coal cleaning refuse. The composite particles are durable and extremely resistant to environmental and chemical forces. 3 figs.

  17. Hardened, environmentally disposable composite granules of coal cleaning refuse, coal combustion waste, and other wastes, and method preparing the same

    DOEpatents

    Burnet, George; Gokhale, Ashok J.

    1990-07-10

    A hardened, environmentally inert and disposable composite granule of coal cleaning refuse and coal combustion waste, and method for producing the same, wherein the coal combustion waste is first granulated. The coal cleaning refuse is pulverized into fine particles and is then bound, as an outer layer, to the granulated coal combustion waste granules. This combination is then combusted and sintered. After cooling, the combination results in hardened, environmentally inert and disposable composite granules having cores of coal combustion waste, and outer shells of coal cleaning refuse. The composite particles are durable and extremely resistant to environmental and chemical forces.

  18. Catalytic Unmixed Combustion of Coal with Zero Pollution

    SciTech Connect

    George Rizeq; Parag Kulkarni; Raul Subia; Wei Wei

    2005-12-01

    GE Global Research is developing an innovative energy-based technology for coal combustion with high efficiency and near-zero pollution. This Unmixed Combustion of coal (UMC-Coal) technology simultaneously converts coal, steam and air into two separate streams of high pressure CO{sub 2}-rich gas for sequestration, and high-temperature, high-pressure vitiated air for producing electricity in gas turbine expanders. The UMC process utilizes an oxygen transfer material (OTM) and eliminates the need for an air separation unit (ASU) and a CO{sub 2} separation unit as compared to conventional gasification based processes. This is the final report for the two-year DOE-funded program (DE-FC26-03NT41842) on this technology that ended in September 30, 2005. The UMC technology development program encompassed lab- and pilot-scale studies to demonstrate the UMC concept. The chemical feasibility of the individual UMC steps was established via lab-scale testing. A pilot plant, designed in a related DOE funded program (DE-FC26-00FT40974), was reconstructed and operated to demonstrate the chemistry of UMC process in a pilot-scale system. The risks associated with this promising technology including cost, lifetime and durability OTM and the impact of contaminants on turbine performance are currently being addressed in detail in a related ongoing DOE funded program (DE-FC26-00FT40974, Phase II). Results obtained to date suggest that this technology has the potential to economically meet future efficiency and environmental performance goals.

  19. Coal Cleaning Using Resonance Disintegration for Mercury and Sulfur Reduction Prior to Combustion

    SciTech Connect

    Andrew Lucero

    2005-04-01

    Coal-cleaning processes have been utilized to increase the heating value of coal by extracting ash-forming minerals in the coal. These processes involve the crushing or grinding of raw coal followed by physical separation processes, taking advantage of the density difference between carbonaceous particles and mineral particles. In addition to the desired increase in the heating value of coal, a significant reduction of the sulfur content of the coal fed to a combustion unit is effected by the removal of pyrite and other sulfides found in the mineral matter. WRI is assisting PulseWave to develop an alternate, more efficient method of liberating and separating the undesirable mineral matter from the carbonaceous matter in coal. The approach is based on PulseWave's patented resonance disintegration technology that reduces that particle size of materials by application of destructive resonance, shock waves, and vortex generating forces. Illinois No.5 coal, a Wyodak coal, and a Pittsburgh No.8 coal were processed using the resonance disintegration apparatus then subjected to conventional density separations. Initial microscopic results indicate that up to 90% of the pyrite could be liberated from the coal in the machine, but limitations in the density separations reduced overall effectiveness of contaminant removal. Approximately 30-80% of the pyritic sulfur and 30-50% of the mercury was removed from the coal. The three coals (both with and without the pyritic phase separated out) were tested in WRI's 250,000 Btu/hr Combustion Test Facility, designed to replicate a coal-fired utility boiler. The flue gases were characterized for elemental, particle bound, and total mercury in addition to sulfur. The results indicated that pre-combustion cleaning could reduce a large fraction of the mercury emissions.

  20. Coal liquefaction process

    SciTech Connect

    Urban, P.; Hilfman, L.

    1986-09-09

    A coal liquefaction process is described comprising reacting coal with a hydrocarbonaceous solvent at coal liquefaction conditions in the presence of an oil shale residue catalyst comprising organic and inorganic fractions. The catalyst is produced by the treatment of oil shale in the presence of an inert gas at a temperature in the range from about 500/sup 0/F to about 825/sup 0/F and at a pressure in the range of from about atmospheric to about 2000 psig for a period of time of from about 0.1 to 10 hours.

  1. Coal liquefaction process

    DOEpatents

    Wright, C.H.

    1986-02-11

    A process is described for the liquefaction of coal wherein raw feed coal is dissolved in recycle solvent with a slurry containing recycle coal minerals in the presence of added hydrogen at elevated temperature and pressure. The highest boiling distillable dissolved liquid fraction is obtained from a vacuum distillation zone and is entirely recycled to extinction. Lower boiling distillable dissolved liquid is removed in vapor phase from the dissolver zone and passed without purification and essentially without reduction in pressure to a catalytic hydrogenation zone where it is converted to an essentially colorless liquid product boiling in the transportation fuel range. 1 fig.

  2. Coal liquefaction process

    DOEpatents

    Wright, Charles H.

    1986-01-01

    A process for the liquefaction of coal wherein raw feed coal is dissolved in recycle solvent with a slurry containing recycle coal minerals in the presence of added hydrogen at elevated temperature and pressure. The highest boiling distillable dissolved liquid fraction is obtained from a vacuum distillation zone and is entirely recycled to extinction. Lower boiling distillable dissolved liquid is removed in vapor phase from the dissolver zone and passed without purification and essentially without reduction in pressure to a catalytic hydrogenation zone where it is converted to an essentially colorless liquid product boiling in the transportation fuel range.

  3. Measurement of spray combustion processes

    NASA Technical Reports Server (NTRS)

    Peters, C. E.; Arman, E. F.; Hornkohl, J. O.; Farmer, W. M.

    1984-01-01

    A free jet configuration was chosen for measuring noncombusting spray fields and hydrocarbon-air spray flames in an effort to develop computational models of the dynamic interaction between droplets and the gas phase and to verify and refine numerical models of the entire spray combustion process. The development of a spray combustion facility is described including techniques for laser measurements in spray combustion environments and methods for data acquisition, processing, displaying, and interpretation.

  4. Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA).

    PubMed

    Idris, Siti Shawalliah; Rahman, Norazah Abd; Ismail, Khudzir

    2012-11-01

    The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value. PMID:22944493

  5. Coal Liquefaction desulfurization process

    DOEpatents

    Givens, Edwin N.

    1983-01-01

    In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide and low molecular weight sulfur compounds, and then reacting the slurry with a solid sulfur getter material, such as iron. The sulfur getter compound, with reacted sulfur included, is then removed with other solids in the slurry.

  6. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Levasseur, A.A.

    1995-11-01

    The Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy is sponsoring the development of advanced coal-cleaning technologies aimed at expanding the use of the nation`s vast coal reserves in an environmentally and economically acceptable manner. Because of the lack of practical experience with deeply beneficiated coal-based fuels, PETC has contracted Combustion Engineering, Inc. to perform a multi-year project on `Combustion Characterization of Beneficiated Coal-Based Fuels.` The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of Beneficiated Coal-Based Fuels (BCs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs.

  7. Sonically Enhanced Combustion of Coal Water Slurry Fuel.

    NASA Astrophysics Data System (ADS)

    Ramachandran, Prakash

    1990-01-01

    An investigation was performed to demonstrate that a high intensity acoustic field can enhance the convective transfer processes occurring during CWSF (coal water slurry fuel) combustion. It was carried out in a 300,000 Btu/h sonic combustor. For the runs conducted, SPLs of 156 dB and 145 dB, respectively, were measured below the fuel injection point and before the exit to the combustor. Frequency was held at 1400 Hz. Combustion efficiency was improved when the extent of burnout was well below 100% and when the droplet size distribution was relatively coarse. The maximum improvement in burnout was 7.9%, under the coarsest atomization conditions investigated. Results from modelling show that sonically enhanced heat transfer plays a negligible role in improving the rate of combustion of CWSF. However, such enhancement may well be important for other applications (e.g. spray drying) involving longer drying times and/or small steady slip velocities. The application of a sonic field improves the rate of combustion of CWSF mainly through increased mass transfer rates, the enhancement being greatest for relatively coarse atomization. It is commonly accepted that the largest particles of fuel are the most likely to avoid full burnout in a practical combustor and thus contribute to erosion, slagging, and fouling via inertial mechanisms. By acting preferentially on these particles, operational difficulties can be minimized.

  8. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Chow, O.K.; Gralton, G.W.; Lachowicz, Y.V.; Laflesh, R.C.; Levasseur, A.A.; Liljedahl, G.N.

    1989-02-01

    This five-year research project was established to provide sufficient data on coal-water fuel (CWF) chemical, physical, and combustion properties to assess the potential for commercial firing in furnaces designed for gas or oil firing. Extensive laboratory testing was performed at bench-scale, pilot-scale (4 {times} 10{sup 6}Btu/hr) and commercial-scale (25 {times} 10{sup 6} to 50 {times} 10{sup 6}Btu/hr) on a cross-section of CWFs. Fuel performance characteristics were assessed with respect to coal properties, level of coal beneficiation, and slurry formulation. The performance of four generic burner designs was also assessed. Boiler performance design models were applied to analyze the impacts associated with conversion of seven different generic unit designs to CWF firing. Equipment modifications, operating limitations, and retrofit costs were determined for each design when utilizing several CWFs. Unit performance analyses showed significantly better load capacity for utility and industrial boilers as the CWF feed coal ash content is reduced to 5% or 2.6%. In general, utility units had more attractive capacity limits and retrofit costs than the industrial boilers and process heaters studied. Economic analyses indicated that conversion to CWF firing generally becomes feasible when differential fuel costs are above $1.00/10{sup 6}Btu. 60 figs., 24 tabs.

  9. CaO interaction in the staged combustion of coal

    SciTech Connect

    Levy, A.; Merryman, E.L.; Rising, B.W.

    1983-12-19

    The LIMB (limestone injection multi-stage burner) process offers special potential for reducing NO/sub x/ and SO/sub x/ by at least 50 percent in coal combustion. This is to be accomplished by adding limestone with fuel and/or air in a low NO/sub x/ burner. This program has been directed to defining the chemistry and kinetics necessary to optimize sulfur capture in LIMB combustion. More specifically, this program has attempted to clarify the role of calcium sulfide in LIMB chemistry. When limestone is added in a staged burner, there is a strong possibility that under certain circumstances CaS is produced in the reducing (fuel-rich) zone of the burner. Since CaS is more stable than CaSO/sub 4/, this affords the opportunity to (1) operate the burner at a higher temperature, 2200 to 2500 F, (2) pass the CaS rapidly through the high temperature zone (before dissociation), and (3) complete the combustion in a lean (air-rich) region where the sulfur is finally retained in CaSO/sub 4/. For these reasons this program has concentrated on the high temperature chemistry and kinetics of CaS. To achieve the program objective, the program was divided into three tasks. These involved (1) a study of CaS formation, (2) a brief examination of CaS oxidation, and (3) a laboratory examination of the combustion of coal in the presence of CaO under first stage, fuel-rich conditions. In the most general sense, the study has shown that the formation of CaS in the reducing zones of the burner may be restricted by competing kinetics and thermodynamics. The addition of lime in LIMB will require special care to optimize the ability to capture sulfur. 36 references, 44 figures, 10 tables.

  10. Application of Fourier-transform infrared (FT-ir) spectroscopy to in-situ studies of coal combustion

    SciTech Connect

    Ottesen, D K; Thorne, L R

    1982-04-01

    The feasibility of using Fourier-transform infrared (FT-ir) spectroscopy for in situ measurement of gas phase species concentrations and temperature during coal combustion is examined. This technique is evaluated in terms of its potential ability to monitor several important chemical and physical processes which occur in pulverized coal combustion. FT-ir absorption measurements of highly sooting, gaseous hydrocarbon/air flames are presented to demonstrate the fundamental usefulness of the technique for in situ detection of gas phase temperatures and species concentrations in high temperature combustion environments containing coal, char, mineral matter and soot particles. Preliminary results for coal/gaseous fuel/air flames are given.

  11. Comprehensive assessment of the specific compounds present in combustion processes. Volume 4. National estimates of emission of specific compounds from coal fired utility boiler plants. Final report

    SciTech Connect

    Lucas, R.M.; Kircher, G.W.

    1985-08-01

    Specimens were acquired from influents and effluents from seven coal-fired utility boilers. The specimens were chemically analyzed for toxic compounds in the polycyclic organic matter group. The specific target compounds were polychlorinated dibenzo(p)-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), selected polynuclear aromatic hydrocarbons (PAHs) and selected phthalates. Twelve PAH compounds and six phthalate compounds were included among the targetted compounds. Naphthalene was the most prevalent PAH compound detected. It was found in the flue gas emissions from all seven facilities. Other PAHs were also detected in the coal at all seven facilities but were only rarely detected in the other media. No PCDDs or PCDFs were detected in any of the acquired specimens. PCBs were only detected in one other media, the influent combustion air.

  12. NOx EMISSIONS PRODUCED WITH COMBUSTION OF POWDER RIVER BASIN COAL IN A UTILITY BOILER

    SciTech Connect

    John S. Nordin; Norman W. Merriam

    1997-04-01

    The objective of this report is to estimate the NOx emissions produced when Powder River Basin (PRB) coal is combusted in a utility boiler. The Clean Air Act regulations specify NOx limits of 0.45 lb/mm Btu (Phase I) and 0.40 lb/mm Btu (Phase II) for tangentially fired boilers, and 0.50 lb/mm 13tu (Phase II) and 0.46 lb/mm Btu (Phase II) for dry-bottom wall-fired boilers. The Clean Air Act regulations also specify other limits for other boiler types. Compliance for Phase I has been in effect since January 1, 1996. Compliance for Phase II goes into effect on January 1, 2000. Emission limits are expressed as equivalent NO{sub 2} even though NO (and sometimes N{sub 2}O) is the NOx species emitted during combustion. Regulatory agencies usually set even lower NOx emission limits in ozone nonattainment areas. In preparing this report, Western Research Institute (WRI) used published test results from utilities burning various coals, including PRB coal, using state-of-the art control technology for minimizing NOx emissions. Many utilities can meet Clean Air Act NOx emission limits using a combination of tight combustion control and low-NOx burners and by keeping furnaces clean (i.e., no slag buildup). In meeting these limits, some utilities also report problems such as increased carbon in their fly ash and excessive furnace tube corrosion. This report discusses utility experience. The theory of NOx emission formation during coal combustion as related to coal structure and how the coal is combusted is also discussed. From this understanding, projections are made for NOx emissions when processed PRB coal is combusted in a test similar to that done with other coals. As will be shown, there are a lot of conditions for achieving low NOx emissions, such as tight combustion control and frequent waterlancing of the furnace to avoid buildup of deposits.

  13. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Boni, A.A.; Helble, J.J.; Srinivasachar, S.; Wilemski, G. ); Sarofim, A.F.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L. ); Huffman, G.P.; Huggins, F.E. )

    1990-11-01

    Objectives of this project are: (1) define the partitioning of inorganic constituents associated with raw coal particles among products (including vapors, aerosols, and residual char/ash particles) formed under conditions representative of pulverized coal flames as a function of the specific (intrinsic and extrinsic) characteristics of the raw coal and the environment in which the transformations occur; and (2) characterize the resultant spectrum of products in detail; elucidate and quantify the fundamental processes by which transformations of the inorganic constituents occur; and develop, based on the information required in a. and b. above, a tractable process'' model capable of predicting the significant features of the transformation process, most importantly, the nature and distribution of products. The work discussed highlights recent accomplishments in modeling synthetic char particle combustion times and temperatures with allowance for oxygen dissociation in the char boundary layer; in developing a continuum model for residual ash information and char fragmentation, permitting a more detailed time-resolved study of ash coalescence within a burning char particle; and in continuing development of the engineering model for ash particle formation. 40 refs., 25 figs., 10 tabs.

  14. Mathematical modeling of the heat treatment and combustion of a coal particle. II. drying stage

    NASA Astrophysics Data System (ADS)

    Enkhzhargal, Kh.; Salomatov, V. V.

    2011-03-01

    This article is a continuation of the previous article in which, with the aid of mathematical modeling, the regime of radiative-convective heating of a coal particle was studied in detail and which was devoted to an analysis of the stage of coal drying, very important in the general picture of coal combustion. The process of coal drying is formulated as the nonlinear Stefan problem with a moving liquid-vapor phase change interface. The rate and time of coal particle drying, the temperature distribution inside a particle, and other parameters of the process have been found approximately analytically depending on the regime of heat supply. A parametric analysis of the influence of physical and regime factors on the dynamics of drying as an integral part of heat treatment of a fuel for its ignition and combustion has been carried out.

  15. Coal liquefaction process

    SciTech Connect

    Minami, R.; Hosoi, T.; Kanou, T.; Okamura, S.; Sunami, Y.

    1984-03-20

    A coal liquefaction process and apparatus therefor are disclosed. According to this invention, a finely divided coal slurry and a solvent are contacted with molecular hydrogen in the presence of a catalyst, the slurry is separated into a gaseous component, a liquid component and a solid residue, the solid residue (which is the liquefaction residue) is then supplied to a molten metal bath together with oxygen gas to generate a gas entraining fine powdery solids, and the thus recovered fine powdery solids are returned to the liquefaction process as a catalyst.

  16. A clean coal combustion technology-slagging combustors

    SciTech Connect

    Chang, S. L.; Berry, G. F.

    1989-03-01

    Slagging combustion is an advanced clean coal technology technique characterized by low NOx and SOx emission, high combustion efficiency, high ash removal, simple design and compact size. The design of slagging combustors has operational flexibility for a wide range of applications, including retrofitting boilers, magnetohydrodynamic combustors, coal-fired gas turbines, gasifiers and hazardous waste incinerators. In recent years, developers of slagging combustors have achieved encouraging progress toward the commercialization of this technology. Although there is a diversity of technical approaches among the developers, they all aim for a compact design of pulverized coal combustion with high heat release and sub-stoichiometric combustion regimes of operation to suppress NOx formation, and most aim to capture sulfur by using sorbent injection in the combustor. If the present pace toward commercialization continues, retrofitting boilers of sizes ranging from 20 to 250 MMBtu/hr (5.9 to 73 MWt) may be available for commercial use in the 1990's. 18 refs., 2 figs.

  17. Remediation of abandoned mines using coal combustion by-products

    SciTech Connect

    Bulusu, S.; Aydilek, A.H.; Petzrick, P.; Guynn, R.

    2005-08-01

    Acid mine drainage (AMD) is a phenomenon that occurs when pyrite that is present in abandoned coal mines comes in contact with oxygen and water, which results in the formation of sulfuric acid and iron hydroxide. Grouting of an abandoned mine with alkaline materials provides a permanent reduction in acid production. This study investigates the success of coal combustion by-product (CCB)-based grout mixtures in reducing AMD. The laboratory phase included testing of grouts with different proportions of Class F fly ash, flue gas desulfurization by-product, fluidized bed combustion by-product, and quicklime, for slump, modified flow, bleed, and strength. Then the selected optimal grout mixture was injected into the Frazee mine, located in Western Maryland. Pre- and post-injection water quality data were collected to assess the long-term success of the grouting operation by analyzing mine water, surface water, and groundwater. Overall, the results indicated that CCB-based grouts can control the acid mine drainage. However, the mechanical properties of the grout are highly critical for the construction phase, and long-term monitoring is essential for evaluating the effectiveness of the grouting process.

  18. Catalytic coal liquefaction process

    DOEpatents

    Garg, D.; Sunder, S.

    1986-12-02

    An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids. 1 fig.

  19. Catalytic coal liquefaction process

    DOEpatents

    Garg, Diwakar; Sunder, Swaminathan

    1986-01-01

    An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids.

  20. The mechanism controlling sticking ash separation and reentrainment in pulverized coal combustion products

    SciTech Connect

    Goldman, Y.; Greenberg, J.B.; Timnat, Y.M.

    1993-12-31

    One of the main areas of development and research in intensification of coal combustion involves burning of pulverized fuel. In this process the overall interaction surface between the reactants (oxygen and coal particles) is about two orders of magnitude bigger than in other methods (stokers, grates, fluidized beds, etc.); such systems of firing are suitable for a wide range of applications from power generation boilers to gas turbines. The ash formed during the combustion process has a strong influence on the combustion intensity and is particularly important for future applications to gas turbines, in a first stage for power generation and later for vehicle powerplants (trucks, ships, eventually airplanes). Improvement of combustion intensity in PF combustors can be attained by two basic techniques. The cyclone furnace is based on the use of tangential injection of air containing pulverized coal, so swirling motion of the combustion products is created in the combustion chamber, with intensive chemical reaction occurring in the boundary layers adjacent to the walls. Attempts were made to reduce NO{sub x} formation and to model mathematically the detailed flow and mixing processes in tangentially fired furnaces. The three-dimensional calculations supply valuable predictions concerning these processes but do not include combustion and heat transfer effects. However such effects can also be calculated. Recently Gillis and Smith evaluated a three-dimensional industrial furnace using a comprehensive code developed at Brigham Young University.

  1. Development and evaluation of coal/water mixture combustion technology. Final report

    SciTech Connect

    Scheffee, R.S.; Rossmeissl, N.P.; Skolnik, E.G.; McHale, E.T.

    1981-08-01

    The objective was to advance the technology for the preparation, storage, handling and combustion of highly-loaded coal/water mixtures. A systematic program to prepare and experimentally evaluate coal/water mixtures was conducted to develop mixtures which (1) burn efficiently using combustion chambers and burners designed for oil, (2) can be provided at a cost less than that of No. 6 oil, and (3) can be easily transported and stored. The program consisted of three principal tasks. The first was a literature survey relevant to coal/water mixture technology. The second involved slurry preparation and evaluation of rheological and stability properties, and processing techniques. The third consisted of combustion tests to characterize equipment and slurry parameters. The first task comprised a complete search of the literature, results of which are tabulated in Appendix A. Task 2 was involved with the evaluation of composition and process variables on slurry rheology and stability. Three bituminous coals, representing a range of values of volatile content, ash content, and hardness were used in the slurries. Task 3 was concerned with the combustion behavior of coal/water slurry. The studies involved first upgrading of an experimental furnace facility, which was used to burn slurry fuels, with emphasis on studying the effect on combustion of slurry properties such as viscosity and particle size, and the effect of equipment parameters such as secondary air preheat and atomization.

  2. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 8, January--March 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-07-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the third quarter of 1991, the following technical progress was made: Calculated the kinetic characteristics of chars from the combustion of spherical oil agglomeration beneficiated products; continued drop tube devolatilization tests of the spherical oil agglomeration beneficiated products; continued analyses of the data and samples from the CE pilot-scale tests of nine fuels; and started writing a summary topical report to include all results on the nine fuels tested.

  3. REDUCTION OF NOx EMISSION FROM COAL COMBUSTION THROUGH OXYGEN ENRICHMENT

    SciTech Connect

    Western Research Institute

    2006-07-01

    BOC Process Gas Solutions and Western Research Institute (WRI) conducted a pilot-scale test program to evaluate the impact of oxygen enrichment on the emissions characteristics of pulverized coal. The combustion test facility (CTF) at WRI was used to assess the viability of the technique and determine the quantities of oxygen required for NOx reduction from coal fired boiler. In addition to the experimental work, a series of Computational Fluid Dynamics (CFD) simulations were made of the CTF under comparable conditions. A series of oxygen enrichment test was performed using the CTF. In these tests, oxygen was injected into one of the following streams: (1) the primary air (PA), (2) the secondary air (SA), and (3) the combined primary and secondary air. Emission data were collected from all tests, and compared with the corresponding data from the baseline cases. A key test parameter was the burner stoichiometry ratio. A series of CFD simulation models were devised to mimic the initial experiments in which secondary air was enriched with oxygen. The results from these models were compared against the experimental data. Experimental evidence indicated that oxygen enrichment does appear to be able to reduce NOx levels from coal combustion, especially when operated at low over fire air (OFA) levels. The reductions observed however are significantly smaller than that reported by others (7-8% vs. 25-50%), questioning the economic viability of the technique. This technique may find favor with fuels that are difficult to burn or stabilize at high OFA and produce excessive LOI. While CFD simulation appears to predict NO amounts in the correct order of magnitude and the correct trend with staging, it is sensitive to thermal conditions and an accurate thermal prediction is essential. Furthermore, without development, Fluent's fuel-NO model cannot account for a solution sensitive fuel-N distribution between volatiles and char and thus cannot predict the trends seen in the

  4. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 9, April--June 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-08-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the second quarter of 1991, the following technical progress was made: completed drop tube furnace devolatilization tests of the spherical oil agglomeration beneficiated products; continued analyses of samples to determine devolatilization kinetics; continued analyses of the data and samples from the CE pilot-scale tests of nine fuels; completed writing a summary topical report including all results to date on he nine fuels tested; and presented three technical papers on the project results at the 16th International Conference on Coal & Slurry Technologies.

  5. Coal liquefaction process

    DOEpatents

    Maa, Peter S.

    1978-01-01

    A process for liquefying a particulate coal feed to produce useful petroleum-like liquid products which comprises contacting; in a series of two or more coal liquefaction zones, or stages, graded with respect to temperature, an admixture of a polar compound; or compounds, a hydrogen donor solvent and particulate coal, the total effluent being passed in each instance from a low temperature zone, or stage to the next succeeding higher temperature zone, or stage, of the series. The temperature within the initial zone, or stage, of the series is maintained about 70.degree. F and 750.degree. F and the temperature within the final zone, or stage, is maintained between about 750.degree. F and 950.degree. F. The residence time within the first zone, or stage, ranges, generally, from about 20 to about 150 minutes and residence time within each of the remaining zones, or stages, of the series ranges, generally, from about 10 minutes to about 70 minutes. Further steps of the process include: separating the product from the liquefaction zone into fractions inclusive of a liquid solvent fraction; hydrotreating said liquid solvent fraction in a hydrogenation zone; and recycling the hydrogenated liquid solvent mixture to said coal liquefaction zones.

  6. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    SciTech Connect

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

  7. The release of iron during coal combustion. Milestone report

    SciTech Connect

    Baxter, L.L.

    1995-06-01

    Iron plays an important role in the formation of both fly ash and deposits in many pulverized-coal-fired boilers. Several authors indicate that iron content is a significant indicator of the slagging propensity of a majority of US bituminous coals, in particular eastern bituminous coals. The pyritic iron content of these coals is shown to be a particularly relevant consideration. A series of investigations of iron release during combustion is reported for a suite of coals ranging in rank from lignite to low-volatile bituminous coal under combustion conditions ranging from oxidizing to inert. Experimental measurements are described in which, under selected conditions, major fractions of the iron in the coal are released within a 25 ms period immediately following coal devolatilization. Mechanistic interpretation of the data suggest that the iron is released as a consequence of oxygen attack on porous pyrrhotite particles. Experimental testing of the proposed mechanism reveals that the release is dependent on the presence of both pyrite in the raw coal and oxygen in the gas phase, that slow preoxidation (weathering) of the pyrite significantly inhibits the iron release, and that iron loss increases as oxygen penetration of the particle increases. Each observation is consistent with the postulated mechanism.

  8. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    USGS Publications Warehouse

    Kolker, A.; Senior, C.L.; Quick, J.C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit. ?? 2006 Elsevier Ltd. All rights reserved.

  9. SPONCOM - a computer program for the prediction of the spontaneous combustion potential of an underground coal mine

    SciTech Connect

    Smith, A.C.; Rumancik, W.P.; Lazzara, C.P.

    1996-12-31

    The United States Bureau of Mines (USBM) developed SPONCOM to aid in the assessment of the spontaneous combustion risk of an underground mining operation. A prior knowledge of the spontaneous combustion risk of the coal and factors that increase that risk can be useful in the planning and development of proactive monitoring, ventilation, and prevention plans for the mining operation. Interactive data input screens prompt the user for information about the coal`s chemical and physical properties, the geologic and mining conditions encountered in the mining of the coal, and the mining practices employed. During the input process, {open_quote}expand{close_quote} screens provide the user with specific information on each input parameter. This information includes a description of the parameter and its effect on the overall spontaneous combustion risk. The program logic determines the coal`s relative spontaneous combustion potential, based on the coal`s proximate and ultimate analyses, and heating value. The program then evaluates the impact of the coal properties, geologic and mining conditions, and mining practices on the spontaneous combustion risk of the mining operation. The program output provides details on each factor that increases the risk of spontaneous combustion.

  10. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 15, October--December 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-03-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; re-analyzed the samples from the pilot-scale ash deposition tests of the first nine feed coals and BCFs using a modified CCSEM technique; updated the topical summary report; and prepared for upcoming tests of new BCFs being produced.

  11. Measurement and modeling of advanced coal conversion processes

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G. ); Smoot, L.D.; Brewster, B.S. )

    1991-09-25

    The objectives of this study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. (VC)

  12. Isotopic signature of atmospheric phosphate emitted from coal combustion

    NASA Astrophysics Data System (ADS)

    Weinberger, Roi; Weiner, Tal; Angert, Alon

    2016-07-01

    Atmospheric deposition of phosphorus (P) serves as an important nutrient input for many terrestrial, marine and freshwater ecosystems, influencing their biogeochemistry and primary production. Fossil fuel combustion, principally coal, is estimated to be a major source of atmospheric-P in industrialized regions. In this research, we aim to find a distinct isotopic signature for fly coal ash, the by-product of coal combustion that is emitted to the atmosphere. This signature could be used to identify coal's contribution to atmospheric-P. For this aim, ten fly coal ash samples from different coal sources, collected by power station filters, were analyzed for P concentrations and stable oxygen isotopic composition (δ18OP). Two inorganic phosphate fractions were analyzed: HCl-extractable and resin-extractable (bioavailable P). High HCl-P concentrations of up to 3500 μg P/g ash were found with a distinct δ18OP range of 17.1-20.5‰. The resin-P concentrations were substantially lower (<8 μg/g) with a wider and significantly lower δ18OP range of 10.6-16.5‰. The ash samples were found to have HCl-P δ18OP higher in ∼0-∼9‰ relative to the source coal. Similar isotopic values were found for ash with the same coal source country, regardless of the power station. Despite the low bioavailable P concentrations, fly ash could still be an important atmospheric P source to the biosphere since these combustion products likely acidify in the atmosphere to become bioavailable. This is also supported by our finding that smaller particles, which are more indicative of the particles actually emitted to the atmosphere, are significantly P-richer. Natural dust sources' δ18OP overlap fly ash's range, complicating the assessment of coal's contribution. Nonetheless, our results provide a new tool for identification of fossil fuel combustion sources in local and global atmospheric P deposition.

  13. Chemical analyses of coal, coal-associated rocks and coal combustion products collected for the National Coal Quality Inventory

    USGS Publications Warehouse

    Hatch, Joseph R.; Bullock, John H.; Finkelman, Robert B.

    2006-01-01

    In 1999, the USGS initiated the National Coal Quality Inventory (NaCQI) project to address a need for quality information on coals that will be mined during the next 20-30 years. At the time this project was initiated, the publicly available USGS coal quality data was based on samples primarily collected and analyzed between 1973 and 1985. The primary objective of NaCQI was to create a database containing comprehensive, accurate and accessible chemical information on the quality of mined and prepared United States coals and their combustion byproducts. This objective was to be accomplished through maintaining the existing publicly available coal quality database, expanding the database through the acquisition of new samples from priority areas, and analysis of the samples using updated coal analytical chemistry procedures. Priorities for sampling include those areas where future sources of compliance coal are federally owned. This project was a cooperative effort between the U.S. Geological Survey (USGS), State geological surveys, universities, coal burning utilities, and the coal mining industry. Funding support came from the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE).

  14. Coal combustion by wet oxidation. Wet oxidation of coal for energy production: test plan and partial results. Interim report

    SciTech Connect

    Bettinger, J.A.

    1980-07-10

    A test plan has been developed which will provide the data necessary to carry out design and economic studies of a steam generating facility, employing the wet oxidation of coal as a heat source. It is obvious, from the literature search and preliminary testing, that the higher the reaction temperature, the more complete the combustion of coal. However, operation at elevated temperatures and pressures present difficult design problems, and the necessary equipment is costly. Operation under these conditions can only be justified by the higher economic value of high pressure and temperature steam. With a reduction in temperature from 550/sup 0/F (228/sup 0/C) to 450/sup 0/F (232/sup 0/C), the operating pressure is reduced by more than half, thus holding down the overall cost of the system. For this reason, our plan is to study both the enhancement of low temperature wet oxidation of coal, and the higher operating regions. The coal selected for the first portion of this test is an Eastern Appalachian high-volatile-A Bituminous type, from the Upper Clarion seam in Pennsylvania. This coal was selected as being a typical high sulfur, eastern coal. The wet oxidation of coal to produce low pressure steam is a process suited for a high sulfur, low grade, coal. It is not intended that wet oxidation be used in all applications with all types of coals, as it does not appear to be competitive, economically, with conventional combustion, therefore the testing will focus on using high sulfur, low grade coals. In the later portion of testing all the available coals will be tested. In addition, a sample of Minnesota peat will be tested to determine if it also can be used in the process.

  15. Coal combustion under conditions of blast furnace injection; [Quarterly] technical report, September 1--November 30, 1993

    SciTech Connect

    Crelling, J.C.

    1993-12-31

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This study is unique in that it will be the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. steel company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals f or such use.

  16. Kinetics of coal combustion. 4th quarterly report

    SciTech Connect

    Gat, N.

    1986-03-01

    The report describes the work performed by the three labs involved in the investigation of coal combustion under the TRW contract. The investigation is divided into three tasks. In the first task, coal volatiles combustion is investigated on a flat flame burner at TRW. The burner and the fuel feed system are described. The determination of the chemical rate parameters from the burning velocity as a function of the flame temperature is discussed as well. The second task, determination of global volatile combustion rates in a well stirred reactor, is performed by Ohio State University. The analytical approach to that task is discussed. Finally, char combustion is investigated at Caltech. A description of some preliminary char characterization measurements is given.

  17. Improved low NOx firing systems for pulverized coal combustion

    SciTech Connect

    McCarthy, K.; Laux, S.; Grusha, J.; Rosin, T.; Hausman, G.L.

    1999-07-01

    More stringent emission limits or the addition of post combustion NOx control create the need for improvements of NOx emissions from pulverized coal boilers. Many boilers retrofitted with Low NOx technology during Phase 1 and Phase 2 of the CAAA fail or marginally meet their requirements. Technical solutions range from addition of overfire air and state-of-the-art low NOx burners to low cost additions of combustion enhancements. Regardless of the combustion NOx control method used, stoichiometries local to the burners must be maintained at the designed values at all times to provide high NOx performance at low efficiency loss due to unburned fuel. This paper describes Foster Wheeler's approach to NOx emission improvements for existing low NOx firing systems. The technology to measure air and coal flow individually for each burner and to control the parameters for optimum combustion are presented and discussed. Field experience shows the installation and advantages of the technology.

  18. MECHANISMS AND OPTIMIZATION OF COAL COMBUSTION

    SciTech Connect

    Kyriacos Zygourakis

    1998-05-01

    We report the development of a novel experimental technique that combines video microscopy and thermogravimetric analysis to optimize the detection of coal and char particle ignitions. This technique is particularly effective for detecting ignitions occurring in coal or char samples containing multiple particles, where other commonly used techniques fail. The new approach also allows for visualization of ignition mechanism. Devolatilized char particles appear to ignite heterogeneously, while coal particles may ignite homogeneously, heterogeneously or through a combination of both mechanisms.

  19. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    C.L. Senior; T. Panagiotou; F.E. Huggins; G.P. Huffman; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F Sarofim; J. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowsky; J.J. Helble; R. Mamani-Paco

    1999-11-01

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1999 to 30 September 1999. During this period the MIT INAA procedures were revised to improve the quality of the analytical results. Two steps have been taken to reduce the analytical errors. A new nitric acid leaching procedure, modified from ASTM procedure D2492, section 7.3.1 for determination of pyritic sulfur, was developed by USGS and validated. To date, analytical results have been returned for all but the last complete round of the four-step leaching procedure. USGS analysts in Denver have halted development of the cold vapor atomic fluorescence technique for mercury analysis procedure in favor of a new direct analyzer for Hg that the USGS is in the process of acquiring. Since early June, emphasis at USGS has been placed on microanalysis of clay minerals in project coals in preparation

  20. Combustion of coal gas fuels in a staged combustor

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  1. Combustion of coal gas fuels in a staged combustor

    NASA Astrophysics Data System (ADS)

    Rosfjord, T. J.; McVey, J. B.; Sederquist, R. A.; Schultz, D. F.

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  2. Direct tuyere injection of oxygen for enhanced coal combustion

    SciTech Connect

    Riley, M.F.

    1996-12-31

    Injecting oxygen directly into the tuyere blowpipe can enhance the ignition and combustion of injected pulverized coal, allowing the efficient use of higher coal rates at high furnace production levels. The effects of direct oxygen injection have been estimated from an analysis of the factors controlling the dispersion, heating, ignition, and combustion of injected coal. Injecting ambient temperature oxygen offers mechanical improvements in the dispersion of coal but provides little thermochemical benefit over increased blast enrichment. Injecting hot oxygen through a novel, patented thermal nozzle lance offers both mechanical and thermochemical benefits over increased enrichment or ambient oxygen injection. Plans for pilot-scale and commercial-scale testing of this new lance are described.

  3. Process for hydrogenating coal and coal solvents

    DOEpatents

    Tarrer, Arthur R.; Shridharani, Ketan G.

    1983-01-01

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

  4. Mutagenicity and carcinogenicity of car exhausts and coal combustion emissions

    SciTech Connect

    Holmberg, B.; Ahlbourg, U.

    1983-01-01

    Car exhausts and coal combustion emissions may cause a spectrum of health effects, varying from annoyance reactions, to bronchitis, to cancer in the respiratory organs and possibly also other organs. Deaths in cardiovascular diseases in particularly sensitive individuals have furthermore, under certain circumstances, been associated with ambient air pollution. The objective of the meeting was to examine the relevance of short-term and long-term biological tests for mutagenicity and carcinogenicity to the assessment of human carcinogenic risk that may arise from exposure to air pollution from motor vehicle exhausts and coal combustion products. (135 refs.)

  5. Removal of mercury from coal-combustion flue-gas

    SciTech Connect

    Livengood, C.D.; Huang, H.S.; Mendelsohn, M.H.; Wu, J.M.

    1995-12-01

    Combustion sources, including those using coal for fuel, contribute a significant fraction of total anthropogenic mercury emissions. Recent field studies have shown that current flue-gas cleanup (FGC) systems are relatively ineffective in controlling elemental mercury, which is a major component of the mercury emissions for many systems. Research at Argonne National Laboratory has been focused on techniques to enhance the capture of elemental mercury in existing FGC systems. For dry processes, these studies have included evaluation of activated carbons and investigation of sorbents based upon chemical pretreatment of low-cost mineral substrates. To enhance the ability of wet scrubbers to capture mercury, the studies have looked at the effects of improved mass transfer through both mechanical and chemical means, as well as the conversion of elemental mercury into more soluble species that can be easily absorbed.

  6. Numerical analysis of the process of combustion and gasification of the polydisperse coke residue of high-ash coal under pressure in a fluidized bed

    SciTech Connect

    A.Y. Maistrenko; V.P. Patskov; A.I. Topal; T.V. Patskova

    2007-09-15

    A numerical analysis of the process of 'wet' gasification of high-ash coal under pressure in a low-temperature fluidized bed has been performed. The applicability of the previously developed computational model, algorithm, and program for the case under consideration has been noted. The presence of 'hot spots' (short-time local heatings) at different points of the bed has been confirmed.

  7. Thermodynamic analysis of the behavior of microimpurities of toxic metals in coal combustion products

    SciTech Connect

    G.Ya. Gerasimov

    2004-01-15

    The thermodynamic approach to the description of the fuel-oxidizer system is used to elucidate the basic laws of behavior of compounds of the most toxic elements/microimpurities in combustion products of coal (Hg, Pb, Cr, Mn, Ni, Co, and As). It has been shown that the distribution of elements over components of the gas and condensed phases strongly depends on the process temperature and the composition of the mineral part of the coal.

  8. Effect of volatile-char interaction on the NO emission from coal combustion.

    PubMed

    Yao, Mingyu; Che, Defu; Liu, Yanhua; Liut, Yinhe

    2008-07-01

    To clarify the effects of volatile-char interaction on the redistribution of fuel-N to N2 during devolatilization and the reduction of NO through gas-solid reactions during combustion, two types of experiments were performed on a novel reactor. The separate combustion of volatile and char and the combustion of entrained pulverized coal, and the formation of NO was examined between 800 and 1100 degrees C by using four typical Chinese coals with different ranks. The effect of volatile-char interaction on fuel-N conversion to NO during combustion was elucidated through comparing the NO emissions from the two types of combustion experiments. The results show that the volatile-char interaction is more important in the redistribution of fuel-N to N2 during devolatilization than in the reduction of NO over 900 degrees C, and a contrary conclusion is obtained below 850 degrees C for all used coals. A specific parameter has been proposed to characterize the relative importance of the volatile-char interaction in the redistribution of fuel-N to N2 during devolatilization to the interaction in the reduction of NO to N2 during simulataneous combustion of volatile and char. The results are of significance for minimizing the NO formation in industrial combustion processes.

  9. NITRIC OXIDE FORMATION DURING PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 K and 1750 K for a residence time of one second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temper...

  10. Interactions of coal gangue and pine sawdust during combustion of their blends studied using differential thermogravimetric analysis.

    PubMed

    Zhang, Yuanyuan; Zhang, Zhezi; Zhu, Mingming; Cheng, Fangqin; Zhang, Dongke

    2016-08-01

    The interactions between coal gangue and pine sawdust during the combustion process were studied using thermogravimetric analysis. The effect of the blending ratio, oxygen concentration and heating rate on the weight loss (TG) and differential thermogravimetric (TGA) profiles was examined. The TG and DTG curves of the blends were not additives of those of the individual materials, suggesting that interactions between coal gangue and pine sawdust had occurred during the combustion, especially in the temperature range of 400-600°C. Kinetic analysis confirmed that the combustion of coal gangue, pine sawdust and their blends was chemical reaction controlled. Further analysis revealed that the interactions between coal gangue and pine sawdust were primarily due to thermal effects rather than structural changes, with the thermal inertia of coal gangue dominating over the behaviour of the blends. The interactions decreased with decreasing the coal gangue ratio in the blend, oxygen concentration and heating rate. PMID:27155794

  11. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2002-08-15

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO2 control, NOx control, and inorganic fine particle and toxic metal emissions will be determined. Previous research has yielded data on trace metal partitioning for MSS by itself, with natural gas assist, for coal plus MSS combustion together, and for coal alone. We have re-evaluated the inhalation health effects of ash aerosol from combustion of MSS both by itself and also together with coal. We have concluded that ash from the co-combustion of MSS and coal is very much worse from an inhalation health point of view, than ash from either MSS by itself or coal by itself. The reason is that ZnO is not the ''bad actor'' as had been suspected before, but the culprit is, rather, sulfated Zn. The MSS supplies the Zn and the coal supplies the sulfur, and so it is the combination of coal and MSS that makes that process environmentally bad. If MSS is to be burned, it should be burned without coal, in the absence of sulfur.

  12. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 10, July--September 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the third quarter of 1991, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed analyses of the samples from the pilot-scale ash deposition tests of unweathered Upper Freeport fuels; completed editing of the first three quarterly reports and sent them to the publishing office; presented the project results at the Annual Contractors` Conference.

  13. Sublimation and combustion of coal particles in the erosion laser torch

    SciTech Connect

    Bulat, A.; Shumrikov, V.; Osenny, V.

    2005-07-01

    Rate of coal particles' combustion in low-temperature plasma is of interest both from application and scientific points of view. Necessity of knowing parameters of the process of coal particles' combustion in plasma torch with the temperature of 2500-3000 K is governed by arising a number of state-of-the-art technological tasks related to the problems of finding new methods of power production, generation of high-calorific synthetic gases and using carbon as a high temperature structural material in nuclear power engineering. The present work deals with a rate of combustion of the sorbed coal particles in the erosion laser torch formed by means of interaction of pulse laser radiation (wave length {lambda} = 1,06 {mu}m, power density j = 10{sup 5} - 10{sup 7} Wcm{sup 2} with coals of various grades (in the wide range of carbon concentrations (80-95 %)). Physical and mathematical modeling of the process of coal particles' sublimation and combustion in non-equilibrium plasma flows with weight-average temperature of 2500-3000 K showed a good convergence of results for the particles of 10-100 {mu}m diameter and satisfactory one for the particles of {gt} 250{mu}m diameter.

  14. Combustion of coal-gas fuels in a staged combustor

    SciTech Connect

    Rosfjord, T J; McVey, J B; Sederquist, R A; Schultz, D F

    1982-01-01

    Gaseous fuels produced from coal resources have been considered for use in industrial gas turbines. Such fuels generally have heating values much lower than the typical gaseous fuel, natural gas; the low heating value could result in unstable or inefficient combustion. Additionally, coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable NO/sub x/ exhaust emission levels. Previous investigations have indicated that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low NO/sub x/ emission operation for coal-derived liquid fuels containing up to 0.8-wt % nitrogen. An experimental program has been conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7% ammonia are presented. The test results permit the following conclusions to be drawn: (1) Staged, rich-lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with heating values of 210 kJ/mol (238 Btu/scf) or higher. (2) Lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with low heating values (84 kJ/mol (95 Btu/scf)). (3) Staged combustion has the ability to limit NH/sub 3/ to NO/sub x/ conversion rates to less than 5%. NO/sub x/ emissions below the EPA limit can readily be achieved.

  15. Coal-feeding mechanism for a fluidized bed combustion chamber

    SciTech Connect

    Gall, R. L.

    1981-06-02

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, E.G. Coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  16. Coal-feeding mechanism for a fluidized bed combustion chamber

    DOEpatents

    Gall, Robert L.

    1981-01-01

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, e.g. coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  17. Zinc isotopic composition of particulate matter generated during the combustion of coal and coal + tire-derived fuels

    USGS Publications Warehouse

    Borrok, D.M.; Gieré, R.; Ren, M.; Landa, E.R.

    2010-01-01

    Atmospheric Zn emissions from the burning of coal and tire-derived fuel (TDF) for power generation can be considerable. In an effort to lay the foundation for tracking these contributions, we evaluated the Zn isotopes of coal, a mixture of 95 wt % coal + 5 wt % TDF, and the particulate matter (PM) derived from their combustion in a power-generating plant. The average Zn concentrations and δ(66)Zn were 36 mg/kg and 183 mg/kg and +0.24‰ and +0.13‰ for the coal and coal + TDF, respectively. The δ(66)Zn of the PM sequestered in the cyclone-type mechanical separator was the lightest measured, -0.48‰ for coal and -0.81‰ for coal+TDF. The δ(66)Zn of the PM from the electrostatic precipitator showed a slight enrichment in the heavier Zn isotopes relative to the starting material. PM collected from the stack had the heaviest δ(66)Zn in the system, +0.63‰ and +0.50‰ for the coal and coal + TDF, respectively. Initial fractionation during the generation of a Zn-rich vapor is followed by temperature-dependent fractionation as Zn condenses onto the PM. The isotopic changes of the two fuel types are similar, suggesting that their inherent chemical differences have only a secondary impact on the isotopic fractionation process.

  18. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1991-01-01

    The main objective of our work is to obtain a specific velocity of the resulting flame and to maintain this flame consistent throughout the experiment. To optimize our work, theoretical study has been conducted relating the flow rate of the premixed gas (gas + air), stoichiometric coal mass flow rate, interparticle distance of the coal particles, number of particles and the max. coal mass flow rate needed to maintain a specific velocity. Runs were made for velocities of 1.5, 2.0, 2.5, and 3.0 m/s.

  19. Structure Based Predictive Model for Coal Char Combustion

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    This unique collaborative project has taken a very fundamental look at the origin of structure, and combustion reactivity of coal chars. It was a combined experimental and theoretical effort involving three universities and collaborators from universities outside the U.S. and from U.S. National Laboratories and contract research companies. The project goal was to improve our understanding of char structure and behavior by examining the fundamental chemistry of its polyaromatic building blocks. The project team investigated the elementary oxidative attack on polyaromatic systems, and coupled with a study of the assembly processes that convert these polyaromatic clusters to mature carbon materials (or chars). We believe that the work done in this project has defined a powerful new science-based approach to the understanding of char behavior. The work on aromatic oxidation pathways made extensive use of computational chemistry, and was led by Professor Christopher Hadad in the Department of Chemistry at Ohio State University. Laboratory experiments on char structure, properties, and combustion reactivity were carried out at both OSU and Brown, led by Principle Investigators Joseph Calo, Robert Essenhigh, and Robert Hurt. Modeling activities were divided into two parts: first unique models of crystal structure development were formulated by the team at Brown (PI'S Hurt and Calo) with input from Boston University and significant collaboration with Dr. Alan Kerstein at Sandia and with Dr. Zhong-Ying chen at SAIC. Secondly, new combustion models were developed and tested, led by Professor Essenhigh at OSU, Dieter Foertsch (a collaborator at the University of Stuttgart), and Professor Hurt at Brown. One product of this work is the CBK8 model of carbon burnout, which has already found practical use in CFD codes and in other numerical models of pulverized fuel combustion processes, such as EPRI's NOxLOI Predictor. The remainder of the report consists of detailed technical

  20. Toxic substances form coal combustion--a co prehemsice assessment

    SciTech Connect

    Huggins, F.; Huffman, G.P.; Shah, N.

    1997-04-01

    The Clean Coal Act Amendments of 1990 identify a number of hazardous air pollutants as candidates for regulation. Should regulations be imposed on emission of these pollutants from coal-fired power plants, a sound understanding of the fundamental principles controlling their formation and partition will be needed. A new Toxics Partitioning Engineering Model (ToPEM) has been developed by a broad consortium to be useful to regulators and utility planners. During the last quarter coal analysis was completed on the final program coal, from the Wyodak Seam of the Powder River Basin, Combustion testing continued, including data collected on the self-sustained combustor. Efforts were directed to identify the governing mechanisms for trace element vaporization from the program coals. Mercury speciation and measurements were continued. Review of the existing trace element and organics emission literature was completed. And, model development was begun.

  1. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. PMID:27136608

  2. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention.

  3. PULVERIZED COAL COMBUSTION: POLLUTANT FORMATION AND CONTROL, 1970-1980

    EPA Science Inventory

    The report documents the support role of EPA's Air and Energy Engineering Research Laboratory in the major research effort directed by EPA in the l970s to understand pollutant formation during pulverized coal combustion (PCC). Understanding the conversion of fuel nitrogen to nit...

  4. Research on coal-water fuel combustion in a circulating fluidized bed / Badanie spalania zawiesinowych paliw węglowo-wodnych w cyrkulacyjnej warstwie fluidalnej

    NASA Astrophysics Data System (ADS)

    Kijo-Kleczkowska, Agnieszka

    2012-10-01

    In the paper the problem of heavily-watered fuel combustion has been undertaken as the requirements of qualitative coals combusted in power stations have been growing. Coal mines that want to fulfill expectations of power engineers have been forced to extend and modernize the coal enrichment plants. This causes growing quantity of waste materials that arise during the process of wet coal enrichment containing smaller and smaller under-grains. In this situation the idea of combustion of transported waste materials, for example in a hydraulic way to the nearby power stations appears attractive because of a possible elimination of the necessary deep dehydration and drying as well as because of elimination of the finest coal fraction loss arising during discharging of silted water from coal wet cleaning plants. The paper presents experimental research results, analyzing the process of combustion of coal-water suspension depending on the process conditions. Combustion of coal-water suspensions in fluidized beds meets very well the difficult conditions, which should be obtained to use the examined fuel efficiently and ecologically. The suitable construction of the research stand enables recognition of the mechanism of coal-water suspension contact with the inert material, that affects the fluidized bed. The form of this contact determines conditions of heat and mass exchange, which influence the course of a combustion process. The specificity of coal-water fuel combustion in a fluidized bed changes mechanism and kinetics of the process.

  5. Management of high sulfur coal combustion residues, issues and practices: Proceedings

    SciTech Connect

    Chugh, Y.P.; Beasley, G.A.

    1994-10-01

    Papers presented at the following sessions are included in this proceedings: (1) overview topic; (2) characterization of coal combustion residues; (3) environmental impacts of residues management; (4) materials handling and utilization, Part I; and (5) materials handling and utilization, Part II. Selected paper have been processed separately for inclusion in the Energy Science and Technology Database.

  6. Method for increasing the calorific value of gas produced by the in situ combustion of coal

    DOEpatents

    Shuck, Lowell Z.

    1978-01-01

    The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

  7. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2003-06-02

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process.

  8. Experimental research of sewage sludge with coal and biomass co-combustion, in pellet form.

    PubMed

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2016-07-01

    Increased sewage sludge production and disposal, as well as the properties of sewage sludge, are currently affecting the environment, which has resulted in legislation changes in Poland. Based on the Economy Minister Regulation of 16 July 2015 (Regulation of the Economy Minister, 2015) regarding the criteria and procedures for releasing wastes for landfilling, the thermal disposal of sewage sludge is important due to its gross calorific value, which is greater than 6MJ/kg, and the problems that result from its use and application. Consequently, increasingly restrictive legislation that began on 1 January 2016 was introduced for sewage sludge storage in Poland. Sewage sludge thermal utilisation is an attractive option because it minimizes odours, significantly reduces the volume of starting material and thermally destroys the organic and toxic components of the off pads. Additionally, it is possible that the ash produced could be used in different ways. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies of the mechanisms and kinetics of sewage sludge, coal and biomass combustion and their co-combustion in spherical-pellet form. Compared with biomass, a higher temperature is required to ignite sewage sludge by flame. The properties of biomass and sewage sludge result in the intensification of the combustion process (by fast ignition of volatile matter). In contrast to coal, a combustion of sewage sludge is determined not only burning the char, but also the combustion of volatiles. The addition of sewage sludge to hard coal and lignite shortens combustion times compared with coal, and the addition of sewage sludge to willow Salix viminalis produces an increase in combustion time compared with willow alone. PMID:27161507

  9. Coal desulfurization process

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.; Gavalas, G. R.; Ganguli, P. S.; Kalfayan, S. H.

    1978-01-01

    A method for chlorinolysis of coal is an organic solvent at a moderate temperautre and atmospheric pressure has been proven to be effective in removing sulfur, particularly the organic sulfur, from coal. Chlorine gas is bubbled through a slurry of moist coal in chlorinated solvent. The chlorinated coal is separated, hydrolyzed and the dechlorinated. Preliminary results of treating a high sulfutr (4.77%S) bituminous coal show that up to 70% organic sulfur, 90% hyritic sulfur and 76% total sulfur can be removed. The treated coal is dechlorinated by heating at 500 C. The presence of moisture helps to remove organic sulfur.

  10. Health effects of coal mining and combustion: carcinogens and cofactors.

    PubMed Central

    Falk, H L; Jurgelski, W

    1979-01-01

    Some polynuclear aromatics (PNA) have been found to be potent carcinogens for all tissues and organs of experimental animals that have been exposed to them, but different dose levels are needed for these effects. They have been known for decades to cause cancer at the site of application but also at certain sites distant from the area of contact. Although some hydrocarbons are potent and complete carcinogens, the majority of related hydrocarbons was originally found to be inactive. Since they generally appear together, it was important to know more about their interaction, particularly whether they would synergize, or antagonize. The polycyclic hydrocarbons have been studied by subcutaneous injection, where they prove very potent carcinogens. They are also very active on the skin of mice where they produce cancer on prolonged application. Inhalation studies, require larger doses yielded negative results until particulate matter was introduced which facilitated the development of lung tumors. Although iron oxide dust was used initially, other dusts were also capable of enhancing the response of the tissue to benzo(a)pyrene carcinogenesis. This point is of importance, particularly since the inhalation of PNA in situations of air pollution or coal mining involves particulates, although of a different type. Soot is not a homogenous substance and several factors determine its properties. Soots will lose some of the absorbed chemicals during their residence in air, but they retain their PNAs for long periods of time when they reach the soil. The carcinogenicity of PNAs in the adsorbed state may be completely absent, depending on particle size of the soot and availability of eluting capability of the tissues or cells in contact with the soot. Whenever the carcinogenic polynuclear aromatics can be eluted they will be active in producing cancer if their residence is adequate. There seems to be no reason to assume that a large increase in coal combustion in the future will

  11. Process for beneficiating coal

    SciTech Connect

    Burgess, L.E.; Fox, K.M.; Herman, D.E.; McGarry, P.E.

    1982-06-01

    Mine run coal is pulverized and the extended surfaces of the coal particles are rendered hydrophobic and oilophilic by a chemical bonding and graft polymerization reaction with a water insoluble organic polymerizable monomer under peroxidation influence in a predominantly water reaction medium. The mineral ash present in the coal and particularly the iron pyrites remains hydrophilic and is separated from the polymeric organic surface bonded coal product in a water washing step wherein the washed coal floats on and is recovered from the water phase and the ash is removed with the separated wash water in a critical wash step. Excess water is removed from the beneficiated hydrophobic surface-altered coal product mechanically. The hydrophobic and oilophilic organic polymeric surface bonded coating about the coal particles is fortified by inclusion of additional unbound free fatty acids by further small additions thereof. The carboxylic acid groups present in the coal-oil product are thereafter converted to a metal soap. The beneficiated coal product can be used ''dry,'' or additional quantities of a liquid hydrocarbon fuel can be incorporated with the ''dry'' beneficiated coal product to produce a flowable fluid or liquid coal product having the rheological property of marked thixotropy. Introduction of this physically induced property into the liquid coal-oil-mixture prevents settling out of the heavier coal particles from the relatively ash-free fluid fuel composition under extended storage periods.

  12. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion.

    PubMed

    Konopa, Stephanie Lucero; Mulholland, James A; Realff, Matthew J; Lemieux, Paul M

    2008-08-01

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO2), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particle-board combustion, consistent with its higher nitrogen content. SO2 emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet.

  13. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion

    SciTech Connect

    Stephanie Lucero Konopa; James A. Mulholland; Matthew J. Realff; Paul M. Lemieux

    2008-08-15

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO{sub 2}), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particleboard combustion, consistent with its higher nitrogen content. S{sub 2} emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet. 13 refs., 5 figs., 1 tab.

  14. [Lead emission amount from coal combustion and its environment effect in Xi'an City].

    PubMed

    Luo, Kunli; Wang, Douhu; Tan, Jianan; Wang, Lizheng; Feng, Fujian; Li, Ribang

    2002-01-30

    For study the lead emission amount from coal combustion and its environment effect, the lead content of coal, ash and cinder of power station and coal-fired boiler, the lead content of dusts in the period of heating time and the non-heating time in Xi'an City were studied in this paper. The results show that amount of lead emission from 1 ton coal combustion, which lead content in coal was 30 g, was 20 g in atmosphere. The rate of lead emission of coal combustion was about 66%. About 10 million tons of coal was straight burning every year in Xi'an City and suburb, those coal mainly come from Permo-Carboniferous coal in Weibei coal mine, Shaanxi, their average lead content was 30 mg/kg. So the total lead emission from coal combustion to atmosphere was about 200 t annually in Xi'an City.

  15. Toxic Substances From Coal Combustion - Phase I Coal Selection and Chaacterization

    SciTech Connect

    A. Kolker; A. Sarofim; C.A. Palmer; C.L. Senior; F.E. Huggins; G.P. Huffman; I. Olmez; N. Shah; R. Finkelman; S. Crowley; T. Zeng

    1998-07-16

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. Over the past decade, a large database identifying the partitioning and emitted concentrations of several toxic metals on the list of HAPs has been developed. Laboratory data have also been generated to help define the general behavior of several elements in combustion systems. These data have been used to develop empirical and probabalistic models to predict emissions of trace metals from coal-fired power plants. While useful for providing average emissions of toxic species, these empirically based models fail when extrapolated beyond their supporting database. This represents a critical gap; over the coming decades, new fuels and combustion systems will play an increasing role in our nation's power generation system. For example, new fuels, such as coal blends or beneficiated fuels, new operating conditions, such as low-NO burners or staged combustion, or new power x systems, for example, those being developed under the DoE sponsored Combustion 2000 programs and integrated gasification combined cycle (IGCC) systems, are all expected to play a role in power generation in the next century. The need for new predictive tools is not limited to new combustion systems, however. Existing combustion systems may have to employ controls for HAPs, should regulations be imposed. Testing of new control methods, at pilot and full scale, is expensive. A sound under-standing of the chemical transformations of both organic and inorganic HAPs will promote the development of new control methods in a cost-effective manner. To ensure that coal-fired power generation proceeds in an environmentally benign fashion, methods for the prediction and

  16. Oxidation of Mercury in Products of Coal Combustion

    SciTech Connect

    Peter Walsh; Giang Tong; Neeles Bhopatkar; Thomas Gale; George Blankenship; Conrad Ingram; Selasi Blavo Tesfamariam Mehreteab; Victor Banjoko; Yohannes Ghirmazion; Heng Ban; April Sibley

    2009-09-14

    scale, burning bituminous coals (Gale, 2006) and blends of bituminous coals with Powder River Basin coal (Gale, 2005). The removal of mercury by fly ash and unburned carbon in the flue gas from combustion of the bituminous coals and blends was reproduced with satisfactory accuracy by the model. The enhancement of mercury capture in the presence of calcium (Gale, 2005) explained a synergistic effect of blending on mercury removal across the baghouse. The extent of mercury oxidation, on the other hand, was not so well described by the simulation, because of oversensitivity of the oxidation process in the model to the concentration of unburned carbon. Combined catalysts and sorbents for oxidation and removal of mercury from flue gas at low temperature were based on surfactant-templated silicas containing a transition metal and an organic functional group. The presence of both metal ions and organic groups within the pore structure of the materials is expected to impart to them the ability to simultaneously oxidize elemental mercury and adsorb the resulting oxidized mercury. Twelve mesoporous organosilicate catalysts/sorbents were synthesized, with and without metals (manganese, titanium, vanadium) and organic functional groups (aminopropyl, chloropropyl, mercaptopropyl). Measurement of mercury oxidation and adsorption by the candidate materials remains for future work.

  17. Formation and use of coal combustion residues from three types of power plants burning Illinois coals

    USGS Publications Warehouse

    Demir, I.; Hughes, R.E.; DeMaris, P.J.

    2001-01-01

    Coal, ash, and limestone samples from a fluidized bed combustion (FBC) plant, a pulverized coal combustion (PC) plant, and a cyclone (CYC) plant in Illinois were analyzed to determine the combustion behavior of mineral matter, and to propose beneficial uses for the power plant ashes. Pyrite and marcasite in coal were converted during combustion to glass, hematite and magnetite. Calcite was converted to lime and anhydrite. The clay minerals were altered to mullite and glass. Quartz was partially altered to glass. Trace elements in coal were partially mobilized during combustion and, as a result, emitted into the atmosphere or adsorbed on fly ash or on hardware on the cool side of the power plants. Overall, the mobilities of 15 trace elements investigated were lower at the FBC plant than at the other plants. Only F and Mn at the FBC plant, F, Hg, and Se at the PC plant and Be, F, Hg, and Se at the CYC plant had over 50% of their concentrations mobilized. Se and Ge could be commercially recovered from some of the combustion ashes. The FBC ashes could be used as acid neutralizing agents in agriculture and waste treatment, and to produce sulfate fertilizers, gypsum wall boards, concrete, and cement. The PC and CYC fly ashes can potentially be used in the production of cement, concrete, ceramics, and zeolites. The PC and CYC bottom ashes could be used in stabilized road bases, as frits in roof shingles, and perhaps in manufacturing amber glass. ?? 2001 Elsevier Science Ltd. All rights reserved.

  18. Thermochemical and trace element behavior of coal gangue, agricultural biomass and their blends during co-combustion.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Cheng, Siwei; Fang, Ting; Lam, Paul Kwan Sing

    2014-08-01

    The thermal decomposition behavior of coal gangue, peanut shell, wheat straw and their blends during combustion were determined via thermogravimetric analysis. The coal gangue/agricultural biomass blends were prepared in four weight ratios and oxidized under dynamic conditions from room temperature to 1000 °C by various heating rates. Kinetic models were carried out to evaluate the thermal reactivity. The overall mass balance was performed to assess the partition behavior of coal gangue, peanut shell and their blends during combustion in a fixed bed reactor. The decomposition processes of agricultural biomass included evaporation, release of volatile matter and combustion as well as char oxidation. The thermal reactivity of coal gangue could be improved through the addition of agricultural biomass in suitable proportion and subsequent appropriate heating rate during combustion. In combination with the heating value and base/acid ratio limitations, a blending ratio of 30% agricultural biomass is conservatively selected as optimum blending.

  19. Coal Combustion Science quarterly progress report, January--March 1993. Task 1, Coal char combustion: Task 2,, Fate of mineral matter

    SciTech Connect

    Hardesty, D.R.; Hurt, R.H.; Baxter, L.L.

    1994-02-01

    The objective of this work is to obtain insights into the mechanisms of combustion, fragmentation, and final burnout, and to use the insights to aid in the interpretation of the quantitative data generated in Subtasks 1 and 2. The initial image sequences for Illinois No. 6 coal confirm the presence of an early near-extinction process (discussed in previous reports) and the asymptotic nature of the carbon burnout process. The technique also provided important new insights into the processes of particle fragmentation and reagglomeration at high burnout. During this quarter, chemical fractionation tests on coals pulverized to different sizes were completed. These data will help us to asses the accuracy of the fuels characterizations for the purpose of interpreting inorganic release during coal devolatilization. Chemical fractionation tests on mineral species are proceeding for the same purposes, but these are not yet completed.

  20. The shell coal gasification process

    SciTech Connect

    Koenders, L.O.M.; Zuideveld, P.O.

    1995-12-01

    Future Integrated Coal Gasification Combined Cycle (ICGCC) power plants will have superior environmental performance and efficiency. The Shell Coal Gasification Process (SCGP) is a clean coal technology, which can convert a wide range of coals into clean syngas for high efficiency electricity generation in an ICGCC plant. SCGP flexibility has been demonstrated for high-rank bituminous coals to low rank lignites and petroleum coke, and the process is well suited for combined cycle power generation, resulting in efficiencies of 42 to 46% (LHV), depending on choice of coal and gas turbine efficiency. In the Netherlands, a 250 MWe coal gasification combined cycle plant based on Shell technology has been built by Demkolec, a development partnership of the Dutch Electricity Generating Board (N.V. Sep). The construction of the unit was completed end 1993 and is now followed by start-up and a 3 year demonstration period, after that the plant will be part of the Dutch electricity generating system.

  1. Oxy-combustion of pulverized coal : modeling of char combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  2. Oxy-combustion of pulverized coal : modeling of char-combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  3. Coal recovery process

    DOEpatents

    Good, Robert J.; Badgujar, Mohan

    1992-01-01

    A method for the beneficiation of coal by selective agglomeration and the beneficiated coal product thereof is disclosed wherein coal, comprising impurities, is comminuted to a particle size sufficient to allow impurities contained therein to disperse in water, an aqueous slurry is formed with the comminuted coal particles, treated with a compound, such as a polysaccharide and/or disaccharide, to increase the relative hydrophilicity of hydrophilic components, and thereafter the slurry is treated with sufficient liquid agglomerant to form a coagulum comprising reduced impurity coal.

  4. Optical and chemical characterization of aerosols emitted from coal, heavy and light fuel oil, and small-scale wood combustion.

    PubMed

    Frey, Anna K; Saarnio, Karri; Lamberg, Heikki; Mylläri, Fanni; Karjalainen, Panu; Teinilä, Kimmo; Carbone, Samara; Tissari, Jarkko; Niemelä, Ville; Häyrinen, Anna; Rautiainen, Jani; Kytömäki, Jorma; Artaxo, Paulo; Virkkula, Aki; Pirjola, Liisa; Rönkkö, Topi; Keskinen, Jorma; Jokiniemi, Jorma; Hillamo, Risto

    2014-01-01

    Particle emissions affect radiative forcing in the atmosphere. Therefore, it is essential to know the physical and chemical characteristics of them. This work studied the chemical, physical, and optical characteristics of particle emissions from small-scale wood combustion, coal combustion of a heating and power plant, as well as heavy and light fuel oil combustion at a district heating station. Fine particle (PM1) emissions were the highest in wood combustion with a high fraction of absorbing material. The emissions were lowest from coal combustion mostly because of efficient cleaning techniques used at the power plant. The chemical composition of aerosols from coal and oil combustion included mostly ions and trace elements with a rather low fraction of absorbing material. The single scattering albedo and aerosol forcing efficiency showed that primary particles emitted from wood combustion and some cases of oil combustion would have a clear climate warming effect even over dark earth surfaces. Instead, coal combustion particle emissions had a cooling effect. Secondary processes in the atmosphere will further change the radiative properties of these emissions but are not considered in this study.

  5. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-08-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, conbustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Sciences, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for the full-scale tests. Approximately nine BCFs will be in dry ultra-fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  6. REDUCTION OF NO{sub x} VIA COAL COMBUSTION CATALYSTS

    SciTech Connect

    Jeff Hare; George Ford; Stephanie Black; Bing Zhou; Stan Harding

    2004-02-13

    Air pollution is a growing concern for both the US government and its citizens. Current legislation is moving in the direction of lower emissions standards for the major pollutants, SO{sub x} and NO{sub x}. The work performed under this DOE grant focused on finding a catalyst that, when added to coal, will effectively reduce the amount of NO{sub x} produced during combustion. The test program was divided into four major tasks: (1) evaluating the impact of a combustion catalyst on nitrogen release; (2) optimizing catalyst formulation; (3) preparing a preliminary economic evaluation; and (4) outlining future test plans, costs and schedule. More than 100 bench-scale, proof-of-concept tests were completed with more than 30 different catalysts, using two different coal types, River Hill Pittsburgh 8 (River Hill) and PRB, under oxidizing and reducing conditions. The results showed that catalysts were effective in increasing, by more than 30%, the nitrogen gas (N{sub 2}) release in River Hill Pittsburgh 8 coal and more than 20% in the PRB coal. Preliminary economics suggest this technology is comparable with current combustion NO{sub x} control technologies such as overfire air addition, SNCR and reburning. Pilot-scale tests are planned in a system with low-NO{sub x} burners to further evaluate the technology.

  7. Diagnostics of combustion process based on flame images analysis and genetic programming

    NASA Astrophysics Data System (ADS)

    Tanaś, J.; Kotyra, A.; Shegebaeva, Jibek

    2015-09-01

    One of the means of assessing the state of combustion process is analyzing data obtained from flame images. Flame images can be used as a source of information of combustion process input parameters such as air flow, fuel expense or fumes temperature. These parameters are crucial for stable and effective combustion. Considering complexity of combustion process and large number of fluctuating variables, genetic programming is an approach that seems most appropriate. Several video streams of co-combusting biomass and coal were recorded at the rate of 150 frames per second with 800x800 resolution. Different image and combustion parameters were processed to determine dependencies between them.

  8. Geochemical database of feed coal and coal combustion products (CCPs) from five power plants in the United States

    USGS Publications Warehouse

    Affolter, Ronald H.; Groves, Steve; Betterton, William J.; William, Benzel; Conrad, Kelly L.; Swanson, Sharon M.; Ruppert, Leslie F.; Clough, James G.; Belkin, Harvey E.; Kolker, Allan; Hower, James C.

    2011-01-01

    The principal mission of the U.S. Geological Survey (USGS) Energy Resources Program (ERP) is to (1) understand the processes critical to the formation, accumulation, occurrence, and alteration of geologically based energy resources; (2) conduct scientifically robust assessments of those resources; and (3) study the impacts of energy resource occurrence and (or) their production and use on both the environment and human health. The ERP promotes and supports research resulting in original, geology-based, non-biased energy information products for policy and decision makers, land and resource managers, other Federal and State agencies, the domestic energy industry, foreign governments, non-governmental groups, and academia. Investigations include research on the geology of oil, gas, and coal, and the impacts associated with energy resource occurrence, production, quality, and utilization. The ERP's focus on coal is to support investigations into current issues pertaining to coal production, beneficiation and (or) conversion, and the environmental impact of the coal combustion process and coal combustion products (CCPs). To accomplish these studies, the USGS combines its activities with other organizations to address domestic and international issues that relate to the development and use of energy resources.

  9. Coal-water slurry fuel internal combustion engine and method for operating same

    DOEpatents

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  10. Development of a coal-fired combustion system for industrial process heating applications. Phase 3 final report, November 1992--December 1994

    SciTech Connect

    1995-09-26

    A three phase research and development program has resulted in the development and commercialization of a Cyclone Melting System (CMS{trademark}), capable of being fueled by pulverized coal, natural gas, and other solid, gaseous, or liquid fuels, for the vitrification of industrial wastes. The Phase 3 research effort focused on the development of a process heater system to be used for producing value added glass products from the vitrification of boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project was to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential for successful commercialization. The demonstration test consisted of one test run with a duration of 105 hours, approximately one-half (46 hours) performed with coal as the primary fuel source (70% to 100%), the other half with natural gas. Approximately 50 hours of melting operation were performed vitrifying approximately 50,000 lbs of coal-fired utility boiler flyash/dolomite mixture, producing a fully-reacted vitrified product.

  11. Development of a coal-fired combustion system for industrial processing heating applications: Appendix A. Phase 3 final report, November 1992--December 1994

    SciTech Connect

    1995-09-26

    A three phase research and development program has resulted in the development and commercialization of a Cyclone Melting System (CMS{trademark}), capable of being fueled by pulverized coal, natural gas, and other solid, gaseous, or liquid fuels, for the vitrification of industrial wastes. The Phase 3 research effort focused on the development of a process heater system to be used for producing value added glass products from the vitrification of boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project was to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential for successful commercialization. The demonstration test consisted of one test run with a duration of 105 hours, approximately one-half (46 hours) performed with coal as the primary fuel source (70% to 100%), the other half with natural gas. Approximately 50 hours of melting operation were performed vitrifying approximately 50,000 lbs of coal-fired utility boiler flyash/dolomite mixture, producing a fully-reacted vitrified product. Appendix A contains 89 figures containing the data from the demonstration tests undertaken under Phase 3.

  12. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    Senior, C.L.; Panagiotou, T.; Huggins, F.E.; Huffman, G.P.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.A.; Mroczkowsky, S.J.; Helble, J.J.; Mamani-Paco, R.

    1999-07-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the period from 1 April 1999 to 30 June 1999. During this quarter low temperature ashing and elemental analysis of the three Phase II coals were completed. Results from MIT and USGS are comparable. Plans were made for measurements of loss of trace elements during devolatilization and for single particle combustion studies at the University of Utah. The iodated charcoal trap was tested on coal combustion flue gas and was shown to collect both Hg and Se in from the vapor phase with 100% efficiency. Data from the University of Arizona self-sustained combustor were analyzed from the combustion of three coals: Ohio, Wyodak and Illinois No. 6. Ash size distributions and enrichment factors for selected trace elements were calculated. The correlation between the concentration of the more volatile trace elements in the ash and the

  13. Kinetics of coal combustion. Third quarterly report

    SciTech Connect

    Fleeter, R.D.; Petach, M.B.; Essenhigh, R.H.; Flagan, R.C.; Gavalas, G.R.; Gat, N.

    1985-10-01

    This report summarizes the work accomplished over the past 3 months. The volatiles combustion kinetics work at TRW has concentrated primarily on improvements in the experimental techniques. The kinetics data is derived from measurements of flame temperature and burning velocity. The measurement technique and procedure have been reviewed, and improvements were made in the apparatus. The report describes in detail the measurement technique and its associated errors. Future work will concentrate on the derivation of chemical kinetics from the experimental data and on burning liquid fuels. The report also describes the volatiles stack combustion work at Ohio State University and the char characterization work at Caltech. This report is prepared on the basis of individual inputs provided by the laboratories involved in the projects.

  14. Pilot Testing of WRI'S Novel Mercury Control Technology by Pre-Combustion Thermal Treatment of Coal

    SciTech Connect

    Alan Bland; Jesse Newcomer; Kumar Sellakumar

    2008-08-17

    The challenges to the coal-fired power industry continue to focus on the emission control technologies, such as mercury, and plant efficiency improvements. An alternate approach to post-combustion control of mercury, while improving plant efficiency deals with Western Research Institute's (WRI)'s patented pre-combustion mercury removal and coal upgrading technology. WRI was awarded under the DOE's Phase III Mercury program, to evaluate the effectiveness of WRI's novel thermal pretreatment process to achieve >50% mercury removal, and at costs of <$30,000/lb of Hg removed. WRI has teamed with Etaa Energy, Energy and Environmental Research Center (EERC), Foster Wheeler North America Corp. (FWNA), and Washington Division of URS (WD-URS), and with project co-sponsors including Electric Power Research Institute (EPRI), Southern Company, Basin Electric Power Cooperative (BEPC), Montana-Dakota Utilities (MDU), North Dakota Industrial Commission (NDIC), Detroit Edison (DTE), and SaskPower to undertake this evaluation. The technical objectives of the project were structured in two phases: Phase I--coal selection and characterization, and bench-and PDU-scale WRI process testing and; and Phase II--pilot-scale pc combustion testing, design of an integrated boiler commercial configuration, its impacts on the boiler performance and the economics of the technology related to market applications. This report covers the results of the Phase I testing. The conclusion of the Phase I testing was that the WRI process is a technically viable technology for (1) removing essentially all of the moisture from low rank coals, thereby raising the heating value of the coal by about 30% for subbituminous coals and up to 40% for lignite coals, and (2) for removing volatile trace mercury species (up to 89%) from the coal prior to combustion. The results established that the process meets the goals of DOE of removing <50% of the mercury from the coals by pre-combustion methods. As such, further

  15. TOXIC SUBSTANCES FROM COAL COMBUSTION A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    A KOLKER; AF SAROFIM; CA PALMER; FE HUGGINS; GP HUFFMAN; J LIGHTY; JJ HELBLE; JOL WENDT; MR AMES; N YAP; R FINKELMAN; R. MAMANI-PACO; SJ MROCZKOWSKY; T PANAGIOTOU; W SEAMES

    1999-01-28

    The technical objectives of this project are: (a) To identify the effect of the mode-of-occurrence of toxic elements in coal on the partitioning of these elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (b) To identify the mechanisms governing the post-vaporization interaction of toxic elements and major minerals or unburnt char, (c) To determine the effect of combustion environment (i.e., fuel rich or fuel lean) on the partitioning of trace elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (d) To model the partitioning of toxic elements among various chemical species in the vapor phase and between the vapor phase and complex aluminosilicate melts, (e) To develop the new Toxics Partitioning Engineering Model (ToPEM), applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. A description of the work plan for accomplishing these objectives is presented in Section 2.1 of this report. The work discussed in this report covers the reporting period from 1 October 1998 to 31 December 1998. During this quarter, basic coal testing at USGS was completed. Total sulfur contents range from 0.43 wt-% in the Wyodak to 2.68 wt-% in the Ohio sample. In the North Dakota and Ohio samples, about half of the total sulfur is pyritic and half is organic. The North Dakota sample also contains a minor amount of sulfate, consistent with the presence of barite in this sample. In the Wyodak sample, the majority of the sulfur is organic. Preliminary mineralogy of the three Phase II coals was determined by SEM/EDX. The Ohio coal contains all of the five most common major phases: quartz, illitic clay, kaolinitic clay, pyrite and calcite. Based on this preliminary work, the North Dakota sample appears to lack both kaolinite and calcite, and the Wyodak sample appears to lack calcite. Subsequent SEM work will attempt to reconfirm

  16. Evaluation of catalytic combustion of actual coal-derived gas

    NASA Astrophysics Data System (ADS)

    Blanton, J. C.; Shisler, R. A.

    1982-02-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  17. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

    1992-11-01

    Results from an experimental investigation of the mechanisms governing the ash aerosol size segregated composition resulting from the combustion of pulverized coal in a laboratory scale down-flow combustor are described. The results of modeling activities used to interpret the results of the experiments conducted under his subtask are also described in this section. Although results from the entire program are included, Phase II studies which emphasized: (1) alkali behavior, including a study of the interrelationship between potassium vaporization and sodium vaporization; and (2) iron behavior, including an examination of the extent of iron-aluminosilicate interactions, are highlighted. Idealized combustion determination of ash particle formation and surface stickiness are also described.

  18. Evaluation of catalytic combustion of actual coal-derived gas

    NASA Technical Reports Server (NTRS)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  19. Grindability and combustion behavior of coal and torrefied biomass blends.

    PubMed

    Gil, M V; García, R; Pevida, C; Rubiera, F

    2015-09-01

    Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5-55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased.

  20. Process for electrochemically gasifying coal

    DOEpatents

    Botts, T.E.; Powell, J.R.

    1985-10-25

    A process is claimed for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution. 7 figs.

  1. Coal-to-Liquids Process Model

    SciTech Connect

    2006-01-01

    A comprehensive Aspen Plus model has been developed to rigorously model coal-to-liquids processes. This portion was developed under Laboratory Directed Research and Development (LDRD) funding. The model is built in a modular fashion to allow rapid reconfiguration for evaluation of process options. Aspen Plus is the framework in which the model is developed. The coal-to-liquids simulation package is an assemble of Aspen Hierarchy Blocks representing subsections of the plant. Each of these Blocks are considered individual components of the Copyright, which may be extracted and licensed as individual components, but which may be combined with one or more other components, to model general coal-conversion processes, including the following plant operations: (1) coal handling and preparation, (2) coal pyrolysis, combustion, or gasification, (3) syngas conditioning and cleanup, (4) sulfur recovery using Claus-SCOT unit operations, (5) Fischer-Tropsch liquid fuels synthesis, (6) hydrocracking of high molecular weight paraffin, (7) hydrotreating of low molecular weight paraffin and olefins, (8) gas separations, and (9) power generation representing integrated combined cycle technology.

  2. Coal-to-Liquids Process Model

    2006-01-01

    A comprehensive Aspen Plus model has been developed to rigorously model coal-to-liquids processes. This portion was developed under Laboratory Directed Research and Development (LDRD) funding. The model is built in a modular fashion to allow rapid reconfiguration for evaluation of process options. Aspen Plus is the framework in which the model is developed. The coal-to-liquids simulation package is an assemble of Aspen Hierarchy Blocks representing subsections of the plant. Each of these Blocks are consideredmore » individual components of the Copyright, which may be extracted and licensed as individual components, but which may be combined with one or more other components, to model general coal-conversion processes, including the following plant operations: (1) coal handling and preparation, (2) coal pyrolysis, combustion, or gasification, (3) syngas conditioning and cleanup, (4) sulfur recovery using Claus-SCOT unit operations, (5) Fischer-Tropsch liquid fuels synthesis, (6) hydrocracking of high molecular weight paraffin, (7) hydrotreating of low molecular weight paraffin and olefins, (8) gas separations, and (9) power generation representing integrated combined cycle technology.« less

  3. Nonaqueous coal cleaning process

    SciTech Connect

    Starbuck, A.E.

    1987-09-22

    This patent describes a method of cyclone cleaning of fine particle coal containing carbonaceous material, ash and pyrites comprising the steps of: a. demoisturizing the coal by immersing the coal in a non-aqueous drying liquid having a vaporization temperature higher than that of water. The drying liquid is maintained at a temperature exceeding the vaporization temperature of water, whereby water in the coal is vaporized from the coal and drying liquid; b. transferring the coal to a non-aqueous, agglomerate inhibiting, carrier liquid miscible with the drying liquid. The carrier liquid is comprised of a liquid mixture of a first liquid having a first specific gravity and a second liquid having a second specific gravity different from the first specific gravity. The carrier liquid's specific gravity is adjusted by using a select amount of each of the first and second liquids to yield a carrier liquid specific gravity intermediate the first and second specific gravities. The carrier liquid specific gravity is greater than 1 less than 1.6 selected for effective separation of carbonaceous material from pyrites and ash for a particular coal and wherein the carrier liquid has the characteristic of extracting non-pyrite forms of sulfur from the coal; and c. cycloning the coal in the carrier liquid with a compound cyclone, wherein a first stream predominantly consisting of carbonaceous material and liquid is separated from a second stream predominantly consisting of ash, pyrites and liquid.

  4. Cofiring coal-water slurry in cyclone boilers: Some combustion issues and considerations

    SciTech Connect

    Carson, W.R.; Tillman, D.

    1997-07-01

    Coal-water slurry (CWS) has become a fuel of opportunity with the ability to impact fuel cost at selected power plants; at the same time it has the potential to reduce emissions of oxides of nitrogen (NO{sub x}) by driving specific combustion mechanisms. CWS, produced from selected fines generated during coal cleaning operations, has been fired extensively at the Seward Generating Station of General Public Utilities (GPU), and testing has been initiated at cyclone plants as well. Initial combustion modeling of cyclones has shown that the critical issues associated with CWS firing in cyclones include the following: (1) the impact of CWS on fuel chemistry, with particular attention to fuel ash chemistry; (2) the impact of CWS on combustion temperatures; (3) the impact of CWS, and the consequent increased gas flow in the cyclones, on combustion processes in the cyclone barrel and potentially on combustion in the primary furnace as well; (4) the consequence of combustion process changes on patterns of heat release in the cyclone barrel and in the primary furnace; (5) the ability of the CWS to impact NO{sub x} emissions in the cyclone; and (6) the impact of CWS on the formation of trace metal emissions. This paper reviews the results of cyclone boiler modeling, and also reviews some results of initial cyclone testing related to the results of the modeling efforts.

  5. Iron catalyzed coal liquefaction process

    DOEpatents

    Garg, Diwakar; Givens, Edwin N.

    1983-01-01

    A process is described for the solvent refining of coal into a gas product, a liquid product and a normally solid dissolved product. Particulate coal and a unique co-catalyst system are suspended in a coal solvent and processed in a coal liquefaction reactor, preferably an ebullated bed reactor. The co-catalyst system comprises a combination of a stoichiometric excess of iron oxide and pyrite which reduce predominantly to active iron sulfide catalysts in the reaction zone. This catalyst system results in increased catalytic activity with attendant improved coal conversion and enhanced oil product distribution as well as reduced sulfide effluent. Iron oxide is used in a stoichiometric excess of that required to react with sulfur indigenous to the feed coal and that produced during reduction of the pyrite catalyst to iron sulfide.

  6. Environmental effects of increased coal utilization: ecological effects of gaseous emissions from coal combustion.

    PubMed Central

    Glass, N R

    1979-01-01

    This report is limited to an evaluation of the ecological and environmental effects of gaseous emissions and aerosols of various types which result from coal combustion. It deals with NOx, SOx, fine particulate, photochemical oxidant and acid precipitation as these pollutants affect natural and managed resources and ecosystems. Also, synergistic effects involving two or more pollutants are evaluated as well as ecosystem level effects of gaseous pollutants. There is a brief summary of the effects on materials and atmospheric visibility of increased coal combustion. The economic implications of ecological effects are identified to the extent they can be determined within acceptable limits. Aquatic and terrestrial effects are distinguished where the pollutants in question are clearly problems in both media. At present, acid precipitation is most abundant in the north central and northeastern states. Total SOx and NOx emissions are projected to remain high in these regions while increasing relatively more in the western than in the eastern regions of the country. A variety of ecological processes are affected and altered by air pollution. Such processes include community succession and retrogression, nutrient biogeochemical cycling, photosynthetic activity, primary and secondary productivity, species diversity and community stability. Estimates of the non health-related cost of air pollutants range from several hundred million dollars to $1.7 billion dollars per year. In general, these estimates include only those relatively easily measured considerations such as the known losses to cultivate crops from acute air pollution episodes or the cost of frequent repainting required as a result of air pollution. No substantial nationwide estimates of losses to forest productivity, natural ecosystem productivity which is tapped by domestic grazing animals and wildlife, and other significant dollar losses are available. PMID:44247

  7. FINE PARTICAL AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt; Wayne S. Seames; Art Fernandez

    2003-09-21

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel.

  8. CHARACTERIZATION OF COAL COMBUSTION BY-PRODUCTS FOR THE RE-EVOLUTION OF MERCURY INTO ECOSYSTEMS

    SciTech Connect

    A.M. Schwalb; J.A. Withum; R.M. Statnick

    2002-07-01

    The U.S. Environmental Protection Agency (EPA) and state environmental agencies are suggesting that mercury (Hg) in coal combustion by-products is re-emitted into local ecosystems by additional processing to final products (i.e., wallboard, etc.), by dissolution into groundwater, or by reactions with anaerobic bacteria. This perception may limit the opportunities to use coal combustion by-products in recycle/reuse applications. In this program, CONSOL Energy Inc., Research & Development (CONSOL) is conducting a comprehensive sampling and analytical program to address this concern. If the results of this work demonstrate that re-emissions of Hg from waste disposal and by-product utilization are over-stated, additional regulations regarding coal combustion, waste disposal, and waste material utilization will not be required. This will result in continued low energy cost that is beneficial to the national economy and stability of local economies that are dependent on coal. The main activities for this quarter were: fly ash and FGD slurry samples from four coal-fired utilities were leached and the analysis was completed; the re-volatilization study has begun; the literature review was completed.

  9. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Chow, O.K.; Patel, R.L.; Levasseur, A.A.

    1987-07-01

    Pittsburgh Energy Technology Center (PETC) of the Department of Energy initiated a comprehensive effort in 1982 to develop the necessary performance and cost data and to assess the commercial viability of coal-water fuels (CWFs) as applied to representative utility and industrial units. The effort comprised six tasks beginning with coal resource evaluation and culminating in the assessment of the technical and economic consequences of switching representative commercial units from oil to state-of-the-art CWF firing. Extensive bench, pilot and commercial-scale tests were performed to develop necessary CWF combustion and fireside performance data for the subsequent boiler performance analyses and retrofit cost estimates. Discussions on transport, rheology, combustion properties, and ash characterization are included. 11 refs., 9 figs., 7 tabs.

  10. Development of coal combustion sensitivity test for smoke detectors

    SciTech Connect

    Edwards, J.C.; Morrow, G.S.

    1995-09-01

    Standard smoldering and flaming combustion tests using small coal samples have been developed by the US Bureau of Mines as a method to evaluate the response of a smoke detector. The tests are conducted using a standard smoke box designed and constructed according to Underwriters Laboratories. The tests provide a standard, easily reproducible smoke characteristic for smoldering and flaming coal combustion, based upon a comparison of the smoke optical density and the response of a standard ionization chamber to the smoke. With these standard tests, the range of threshold limits for the response of a smoke detector and the detector`s reliability can be evaluated for nearly identical smoke visibility and smoke physical characteristics. The detector`s threshold response limits and reliability need to be well defined prior to the instrument`s use as part of a mine fire warning system for improved mine safety.

  11. [Fluorine removal efficiency of organic-calcium during coal combustion].

    PubMed

    Liu, Jing; Liu, Jian-Zhong; Zhou, Jun-Hu; Xiao, Hai-Ping; Cen, Ke-Fa

    2006-08-01

    Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.

  12. EFFECTS OF IRON CONTENT IN COAL COMBUSTION FLY ASHES ON SPECIATION OF MERCURY

    EPA Science Inventory

    The paper discusses the effects of iron content in coal combustion fly ashes on speciation of mercury. (NOTE: The chemical form of mercury species in combustion flue gases is an important influence on the control of mercury emissions from coal combustion). The study focused on th...

  13. Combustion of dense streams of coal particles. Final report, August 29, 1990--February 28, 1994

    SciTech Connect

    Annamalai, K.; Gopalakrishnan, C.; Du, X.

    1994-05-01

    The USA consumes almost 94 quads of energy (1 quad = 10{sup 15} BTU or 1.05 {times} 10{sup 15} KJ). The utilities account for about 30 quads of fossil energy where coal is predominantly used as energy source. The coal is ground to finer size and fired into the boiler as dense suspension. Under dense conditions, the particles burn at slower rate due to deficient oxygen within the interparticle spacing. Thus interactions exist amongst the particles for dense clouds. While the earlier literature dealt with combustion processes of isolated particles, the recent research focusses upon the interactive combustion. The interactive combustion studies include arrays consisting of a finite number of particles, and streams and clouds of a large number of particles. Particularly stream combustion models assume cylindrical geometry and predict the ignition and combustion characteristics. The models show that the ignition starts homogeneously for dense streams of coal particles and the ignition time show a minimum as the stream denseness is increased, and during combustion, there appears to be an inner flame within the stream and an outer flame outside the stream for a short period of time. The present experimental investigation is an attempt to verify the model predictions. The set-up consists of a flat flame burner for producing hot vitiated gases, a locally fluidizing feeder system for feeding coal particles, a particle collection probe for collecting particles and an image processing system for analyzing the flame structure. The particles are introduced as a stream into the hot gases and subsequently they ignite and burn. The ash % of fired and collected particles are determined and used to estimate the gasification efficiency or burnt fraction. The parametric studies include gas temperature, oxygen % in gases, residence time, and A:F ratio of the stream.

  14. Preparation and evaluation of coal-derived activated carbons for removal of mercury vapor from simulated coal combustion flue fases

    USGS Publications Warehouse

    Hsi, H.-C.; Chen, S.; Rostam-Abadi, M.; Rood, M.J.; Richardson, C.F.; Carey, T.R.; Chang, R.

    1998-01-01

    Coal-derived activated carbons (CDACs) were tested for their suitability in removing trace amounts of vapor-phase mercury from simulated flue gases generated by coal combustion. CDACs were prepared in bench-scale and pilot-scale fluidized-bed reactors with a three-step process, including coal preoxidation, carbonization, and then steam activation. CDACs from high-organicsulfur Illinois coals had a greater equilibrium Hg0 adsorption capacity than activated carbons prepared from a low-organic-sulfur Illinois coal. When a low-organic-sulfur CDAC was impregnated with elemental sulfur at 600 ??C, its equilibrium Hg0 adsorption capacity was comparable to the adsorption capacity of the activated carbon prepared from the high-organicsulfur coal. X-ray diffraction and sulfur K-edge X-ray absorption near-edge structure examinations showed that the sulfur in the CDACs was mainly in organic forms. These results suggested that a portion of the inherent organic sulfur in the starting coal, which remained in the CDACs, played an important role in adsorption of Hg0. Besides organic sulfur, the BET surface area and micropore area of the CDACs also influenced Hg0 adsorption capacity. The HgCl2 adsorption capacity was not as dependent on the surface area and concentration of sulfur in the CDACs as was adsorption of Hg0. The properties and mercury adsorption capacities of the CDACs were compared with those obtained for commercial Darco FGD carbon.

  15. HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

    SciTech Connect

    Chris Guenther, Ph.D.

    2003-01-28

    SRI has completed the NBFZ test program, made modification to the experimental furnace for the HPBO test. The NBFZ datasets provide the information NEA needs to simulate the combustion and fuel-N conversion with detailed chemical reaction mechanisms. BU has determined a linear swell of 1.55 corresponding to a volumetric increase of a factor of 3.7 and a decrease in char density by the same factor. These results are highly significant, and indicate significantly faster burnout at elevated pressure due to the low char density and large diameter.

  16. A summary report on combustion and gasification processes

    SciTech Connect

    Rath, L.K.; Lee, G.T.

    1996-08-01

    Six poster papers regarding combustion and gasification were reviewed. These six papers address various different technology subjects: (1) underground coal gasification modeling, (2) wood gasification kinetics, (3) heat transfer surface pretreatment by iron implantation, (4) coal water slurry stabilization technology, (5) coal log pipeline technology, and (6) nuclear reactor decontamination. Summaries and comments of the following papers are presented: Characterization of Flow and Chemical Processes in an Underground Gasifier at Great Depth; Model for Reaction Kinetics in Pyrolysis of Wood; Development of a Stainless Steel Heat Transfer Surface with Low Scaling Tendency; Storage and Transportation of Coal Water Mixtures; Coal Log Pipeline: Development Status of the First Commercial System; and Decontamination of Nuclear Systems at the Grand Gulf Nuclear Station.

  17. Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

    USGS Publications Warehouse

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1990-01-01

    Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

  18. Coal liquefaction process with enhanced process solvent

    DOEpatents

    Givens, Edwin N.; Kang, Dohee

    1984-01-01

    In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

  19. HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

    SciTech Connect

    Chris Guenther

    2002-10-28

    The modifications to the SRT-RCFR facility described in the June report were completed. As a result of these changes, the furnace hot zone was increased in length from 7 cm to 15.5 cm. The injector region of the furnace, providing entrainment and sheath flows, was unchanged, while the flow path from the exit of the furnace to the sample collection section was shortened by approximately 10 cm. The modified facility was used to resume testing of Pittsburgh No. 8 coal at 10 atm. The first goal was to confirm that the facility now provides true secondary pyrolysis test conditions. That is, the tar product should be completely converted to soot even in the absence of oxygen in the gas stream. We have now performed four tests with pure argon carrier gas, and have consistently observed voluminous soot product with little or no evidence of tar. Thus, this objective was met. The clogging problems for Pittsburgh No. 8 coal under secondary pyrolysis test conditions may preclude achieving this data point. In that case, we will make measurements under oxidizing conditions, which are expected to eliminate the clogging, and to gradually reduce the oxygen content to the point where product yields can reliably be extrapolated to the zero oxygen case.

  20. Coal combustion under conditions of blast furnace injection. Technical report, March 1, 1994--May 31, 1994

    SciTech Connect

    Crelling, J.C.

    1994-09-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This proposal is a follow-up to one funded for the 1992-93 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter samples of two feed coals and the IBCSP 112 (Herrin No. 6) were prepared for reactivity testing and compared to blast furnace coke, and char fines taken from an active blast furnace. As the initial part of a broad reactivity analysis program, these same samples were also analyzed on a thermogravimetric analyzer (TGA) to determine their combustion and reactivity properties.

  1. Slag processing system for direct coal-fired gas turbines

    DOEpatents

    Pillsbury, Paul W.

    1990-01-01

    Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The systems include a primary combustion compartment coupled to an impact separator for removing molten slag from hot combustion gases. Quenching means are provided for solidifying the molten slag removed by the impact separator, and processing means are provided forming a slurry from the solidified slag for facilitating removal of the solidified slag from the system. The released hot combustion gases, substantially free of molten slag, are then ducted to a lean combustion compartment and then to an expander section of a gas turbine.

  2. Combustion process science and technology

    NASA Technical Reports Server (NTRS)

    Hale, Robert R.

    1989-01-01

    An important and substantial area of technical work in which noncontact temperature measurement (NCTM) is desired is that involving combustion process research. In the planning for this workshop, it was hoped that W. Serignano would provide a briefing regarding the experimental requirements for thermal measurements to support such research. The particular features of thermal measurement requirements included those describing the timeline for combustion experiments, the requirements for thermal control and diagnostics of temperature and other related thermal measurements and the criticality to the involved science to parametric features of measurement capability including precision, repeatability, stability, and resolution. In addition, it was hoped that definitions could be provided which characterize the needs for concurrent imaging as it relates to science observations during the conduct of experimentation.

  3. Catalytic effects of minerals on NOx emission from coal combustion

    SciTech Connect

    Yao, M.Y.; Che, D.F.

    2007-07-01

    The catalytic effects of inherent mineral matters on NOx emissions from coal combustion have been investigated by a thermo-gravimetric analyzer (TGA) equipped with a gas analyzer. The effect of demineralization and the individual effect of Na, K, Ca, Mg, and Fe on the formation of NOx are studied as well as the combined catalytic effects of Ca + Na and Ca + Ti. Demineralization causes more Fuel-N to retain in the char, and reduction of NOx mostly. But the mechanistic effect on NOx formation varies from coal to coal. Ca and Mg promote NOx emission. Na, K, Fe suppress NOx formation to different extents. The effect of transition element Fe is the most obvious. The combination of Ca + Na and Ca + Ti can realize the simultaneous control of sulfur dioxide and nitrogen oxides emissions.

  4. Thermally induced structural changes in coal combustion

    SciTech Connect

    Gavalas, G.R.; Flagan, R.C.

    1990-01-17

    The effect of particle shape on char burnout is investigated in the limit of shrinking core combustion. As a first step, the particle temperature is assumed to proceed in the shrinking core regime and under conditions of negligible Stefan flow. The problem then reduces to calculating the oxygen concentration field around a non-spherical particle with the oxidation reaction taking place on the external surface. This problem has been addressed by an analytical technique and a numerical technique. An analytical technique known as domain perturbation'' was used to examine the change due to reaction in the shape of a slightly nonspherical, but axisymmetric, particle. It was found that the aspect ratio always increases with conversion, i.e., the particle becomes less spherical. A numerical technique, based on the boundary integral'' method was developed to handle the case of an axisymmetric particle with otherwise arbitrary shape. Numerical results are presented which again show the aspect ratio to increase with conversion. 8 refs.

  5. Structure-Based Predictive model for Coal Char Combustion.

    SciTech Connect

    Hurt, R.; Calo, J.; Essenhigh, R.; Hadad, C.; Stanley, E.

    1997-06-25

    During the second quarter of this project, progress was made on both major technical tasks. Three parallel efforts were initiated on the modeling of carbon structural evolution. Structural ordering during carbonization was studied by a numerical simulation scheme proposed by Alan Kerstein involving molecular weight growth and rotational mobility. Work was also initiated to adapt a model of carbonaceous mesophase formation, originally developed under parallel NSF funding, to the prediction of coke texture. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. Boston University has initiated molecular dynamics simulations of carbonization processes and Ohio State has begun theoretical treatment of surface reactions. Experimental work has also begun on model compound studies at Brown and on pilot-scale combustion systems with widely varying flame types at OSE. The work on mobility / growth models shows great promise and is discussed in detail in the body of the report.

  6. Combustion Engineering Integrated Coal Gasification Combined Cycle Repowering Project: Clean Coal Technology Program

    SciTech Connect

    Not Available

    1992-03-01

    On February 22, 1988, DOE issued Program Opportunity Notice (PON) Number-DE-PS01-88FE61530 for Round II of the CCT Program. The purpose of the PON was to solicit proposals to conduct cost-shared ICCT projects to demonstrate technologies that are capable of being commercialized in the 1990s, that are more cost-effective than current technologies, and that are capable of achieving significant reduction of SO[sub 2] and/or NO[sub x] emissions from existing coal burning facilities, particularly those that contribute to transboundary and interstate pollution. The Combustion Engineering (C-E) Integrated Coal Gasification Combined Cycle (IGCC) Repowering Project was one of 16 proposals selected by DOE for negotiation of cost-shared federal funding support from among the 55 proposals that were received in response to the PON. The ICCT Program has developed a three-level strategy for complying with the National Environmental Policy Act (NEPA) that is consistent with the President's Council on Environmental Quality regulations implementing NEPA (40 CFR 1500-1508) and the DOE guidelines for compliance with NEPA (10 CFR 1021). The strategy includes the consideration of programmatic and project-specific environmental impacts during and subsequent to the reject selection process.

  7. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

    Prof. Harold H. Schobert; Dr. M. Mercedes Maroto-Valer; Ms. Zhe Lu

    2001-09-29

    The implementation of increasingly stringent Clean Air Act Regulations by the coal utility industry has resulted in an increase in the concentration of unburned carbon in coal combustion fly ash. In 1999, around 6 million tons of unburned carbon were disposed in the US, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, this report evaluates and compares several routes for the production of activated carbons from unburned carbon, including physical activation with steam or CO{sub 2}, and chemical activation using KOH pretreatment. During the present reporting period (June 30, 2000--June 29, 2001), Task 1 ''Procurement and characterization of CCBPs'' was concluded, including samples from pulverized utility boilers, a utility cyclone unit equipped with a beneficiation technology, a suspension-fired research boiler, and a class C fly ash. The characterization studies showed that the samples collected have significantly different carbon contents, as determined by the ASTM C114 procedure, with the sample from the cyclone unit containing the highest carbon content (LOI of {approx} 80%), since this unit has been retrofitted with a technology to separate the unburned carbon from the fly ash. The porosity of the samples assembled was characterized by N{sub 2} adsorption isotherms at 77K. The surface areas of the class F fly ash samples from pulverized coal combustors are between 30-40 m{sup 2}/g, while the samples from the suspension-fired research boiler had surface area around 115 m{sup 2}/g. As expected, the surface areas of the class C ash is much higher than that of the class F ashes, with values up to 390 m{sup 2}/g. In addition, during the current reporting period, also Task 2 ''Development of activated carbons'' and Task 3

  8. Influence of carbon structure and mineral association of coals on their combustion characteristics for pulverized coal injection (PCI) application

    SciTech Connect

    Gupta, S.; Al-Omari, Y.; Sahajwalla, V.; French, D.

    2006-06-15

    The influence of carbon structure and mineral matter of three pulverized coals on their char characteristics including reactivity was studied under a range of combustion conditions in a drop tube furnace (DTF) and thermogravimetric (TGA) furnace for PCI application. Physical and chemical properties of coals and their combustion derivatives were characterized by automated reflectogram. X-ray diffraction, scanning electron microscope, and BET N{sub 2} adsorption. The QEMSCAN{asterisk} technique was used to characterize the heterogeneous nature of minerals of discrete coal particles. The TGA char reactivity was related to the proportion of coal particles displaying strong association of calcium/sulfur phases with carbon matrix to highlight the catalytic influence of minerals on char reactivity at low temperatures. The study suggested that during DTF combustion tests at 1200{sup o}C, char reaction rates might have been catalyzed by coal minerals, particularly due to illite and its association with carbon. Under the same combustion conditions, most of the coal minerals did not transform significantly to slag phases. Coal burnout was found to improve significantly in a combustion temperature range of 1200 to 1500{sup o}C. The improvement of coal burnout with temperature appeared to be influenced by coal properties, particularly as a function of the chemical nature of minerals, as well as the degree of associations with other minerals. The study implies that coals with similar mineral compositions might not necessarily reflect similar combustion behavior due to the differences in their associations with other phases.

  9. Upgrading low rank coal using the Koppelman Series C process

    SciTech Connect

    Merriam, N.W., Western Research Institute

    1998-01-01

    Development of the K-Fuel technology began after the energy shortage of the early 1970s in the United States led energy producers to develop the huge deposits of low-sulfur coal in the Powder River Basin (PRB) of Wyoming. PRB coal is a subbituminous C coal containing about 30 wt % moisture and having heating values of about 18.6 megajoules/kg (8150 Btu/lb). PRB coal contains from 0.3 to 0.5 wt % sulfur, which is nearly all combined with the organic matrix in the coal. It is in much demand for boiler fuel because of the low-sulfur content and the low price. However, the low-heating value limits the markets for PRB coal to boilers specially designed for the high- moisture coal. Thus, the advantages of the low-sulfur content are not available to many potential customers having boilers that were designed for bituminous coal. This year about 250 million tons of coal is shipped from the Powder River Basin of Wyoming. The high- moisture content and, consequently, the low-heating value of this coal causes the transportation and combustion of the coal to be inefficient. When the moisture is removed and the heating value increased the same bundle of energy can be shipped using one- third less train loads. Also, the dried product can be burned much more efficiently in boiler systems. This increase in efficiency reduces the carbon dioxide emissions caused by use of the low-heating value coal. Also, the processing used to remove water and restructure the coal removes sulfur, nitrogen, mercury, and chlorides from the coal. This precombustion cleaning is much less costly than stack scrubbing. PRB coal, and other low-rank coals, tend to be highly reactive when freshly mined. These reactive coals must be mixed regularly (every week or two) when fresh, but become somewhat more stable after they have aged for several weeks. PRB coal is relatively dusty and subject to self-ignition compared to bituminous coals. When dried using conventional technology, PRB coal is even more dusty and

  10. Toxic Substances from Coal Combustion - Forms of Occurrence Analyses

    SciTech Connect

    Allan Kolker; Curtis A. Palmer; Harvey E. Belkin; Jason Willet; Kathleen C. Kolb; Robert B. Finkelman; Sharon S. Crowley; Stanley J. Mroczkowski

    1998-12-14

    In a cooperative agreement with DOE (Contract No. DE- AC22- 95101), the USGS has participated with Physical Sciences, Inc. (PSI) in a project entitled "Toxic Substances From Coal Combustion -A Comprehensive Assessment". Samples from the Pittsburgh, Elkhorn/ Hazard, Illinois No. 6, and Wyodak program coals were examined to determine the mode of occurrence of selected trace elements (As, Se, Cr, Hg, and Ni) using selective leaching, scanning electron microscopy, electron microprobe analysis, and X- ray diffraction techniques. Among other findings, our results indicate that the bulk of the arsenic in the Pittsburgh and Illinois No. 6 coals is in pyrite. High percentages (60- 80%) of arsenic were leached by nitric acid, and microprobe data confirm the presence of arsenic in pyrite in each of these coals (concentrations ranging from <0.01 to 0.09 wt.% of the pyrite grains). In the Elkhorn/ Hazard coal, arsenic may have several modes of occurrences. About 30 percent of the arsenic in the Elkhorn/ Hazard coal was leached by hydrochloric acid, possibly indicating the presence of arsenates that were formed by the oxidation of pyrite. About 25 percent of the arsenic in the Elkhorn/ Hazard coal was leached by nitric acid, suggesting an association with pyrite. Only sixty percent of the total arsenic in the Elkhorn/ Hazard coal was leached. The low percentage of leachable arsenic may be accounted for by unleached pyrite grains, which were detected in solid residues from the nitric acid leach. In the Wyodak coal, arsenic probably occurs in iron oxides or carbonates (35 % arsenic leached by HCl) and clays (15% arsenic leached by HF). Arsenic in the Wyodak coal may also have an organic association, as indicated by low totals for leaching (50% unleached arsenic). In the four program coals 20 to 45 percent of the chromium was leached by hydrofluoric acid, suggesting an association with silicates (probably illite). Microprobe analysis of the Pittsburgh, Elkhorn/ Hazard, and Illinois

  11. Effect of weathering transformations of coal combustion residuals on trace element mobility in view of the environmental safety and sustainability of their disposal and use. I. Hydrogeochemical processes controlling pH and phase stability.

    PubMed

    Stefaniak, Sebastian; Miszczak, Ewa; Szczepańska-Plewa, Jadwiga; Twardowska, Irena

    2015-06-01

    Coal combustion residuals (CCRs) are one of the most abundant high-volume waste materials disposed in impoundments worldwide. Some methods of CCR recycling, e.g. their use as structural fill for low lying areas or as soil amendment, also expose this material to atmospheric conditions. Combustion processes result in concentration of trace elements in CCRs at about an order of magnitude compared to coal. In order to assess an effect of long-term weathering transformations of CCRs on trace element binding/release, a study has been carried out. It is based on the chemical composition of real pore solutions extracted from the most abundant primary alkaline Class F bituminous CCRs, 0 to >40 years old, sampled from the surface layer and vertical profiles at four different impoundments. In this part of the study, results of a hydrogeochemical simulation of the saturation state of real pore solutions with respect to mineral phases of CCRs with use of the PHREEQC program, related to actual pH values reflecting the full cycle of weathering transformations, have been discussed. This study is the first geochemical proof of the general trend towards a progressive acidification up to pH < 4 of primary alkaline CCRs due to release of protons during internal processes of formation of gibbsite and aluminosilicate minerals, buffered by carbonates at the alkaline - near-neutral stages, and followed by parallel dissolution and buffering by aluminosilicates at pH < 7 after carbonate depletion, to the level up to pH∼3.5-4.0. The intrinsic geochemical changes have resulted in the different susceptibility of trace elements to release and associated changes in risk to the environment at consecutive stages of weathering. PMID:25841194

  12. Effect of weathering transformations of coal combustion residuals on trace element mobility in view of the environmental safety and sustainability of their disposal and use. I. Hydrogeochemical processes controlling pH and phase stability.

    PubMed

    Stefaniak, Sebastian; Miszczak, Ewa; Szczepańska-Plewa, Jadwiga; Twardowska, Irena

    2015-06-01

    Coal combustion residuals (CCRs) are one of the most abundant high-volume waste materials disposed in impoundments worldwide. Some methods of CCR recycling, e.g. their use as structural fill for low lying areas or as soil amendment, also expose this material to atmospheric conditions. Combustion processes result in concentration of trace elements in CCRs at about an order of magnitude compared to coal. In order to assess an effect of long-term weathering transformations of CCRs on trace element binding/release, a study has been carried out. It is based on the chemical composition of real pore solutions extracted from the most abundant primary alkaline Class F bituminous CCRs, 0 to >40 years old, sampled from the surface layer and vertical profiles at four different impoundments. In this part of the study, results of a hydrogeochemical simulation of the saturation state of real pore solutions with respect to mineral phases of CCRs with use of the PHREEQC program, related to actual pH values reflecting the full cycle of weathering transformations, have been discussed. This study is the first geochemical proof of the general trend towards a progressive acidification up to pH < 4 of primary alkaline CCRs due to release of protons during internal processes of formation of gibbsite and aluminosilicate minerals, buffered by carbonates at the alkaline - near-neutral stages, and followed by parallel dissolution and buffering by aluminosilicates at pH < 7 after carbonate depletion, to the level up to pH∼3.5-4.0. The intrinsic geochemical changes have resulted in the different susceptibility of trace elements to release and associated changes in risk to the environment at consecutive stages of weathering.

  13. Combustion Chemistry Diagnostics for Cleaner Processes.

    PubMed

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes.

  14. Combustion Chemistry Diagnostics for Cleaner Processes.

    PubMed

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes. PMID:27440049

  15. Evaluation of fly ash from co-combustion of coal and petroleum coke for use in concrete

    SciTech Connect

    Scott, A.N.; Thomas, M.D.A.

    2007-01-15

    An investigation of fly ash (FA) produced from various blends of coal and petroleum coke (pet coke) fired at Belledune Generating Station, New Brunswick, Canada, was conducted to establish its performance relative to FA derived from coal-only combustion and its compliance with CSA A3000. The FA samples were beneficiated by an electrostatic separation process to produce samples for testing with a range of loss-on-ignition (LOI) values. The results of these studies indicate that the combustion of pet coke results in very little inorganic residue (for example, typically less than 0.5% ash) and the main impact on FA resulting from the co-combustion of coal and up to 25% pet coke is an increase in the unburned carbon content and LOI values. The testing of FA after beneficiation indicates that FA produced from fuels with up to 25% pet coke performs as good as FA produced from the same coal without pet coke.

  16. ON TRIMODAL PARTICLE SIZE DISTRIBUTIONS IN FLY ASH FROM PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Combustion generated fine particles, defined as those with aerodynamic diameters less than 2.5 micrometers, have come under increased regulatory scrutiny because of suspected links to adverse human health effects. Whereas classical theories regarding coal combustion suggest that ...

  17. Coal slurry combustion optimization on single cylinder engine

    SciTech Connect

    Not Available

    1992-09-01

    Under the sponsorship of the US Department of Energy, Morgantown Energy Technology Center, GE Transportation System has been conducting a proof of concept program to use coal water slurry (CWS) fuel to power a diesel engine locomotive since 1988. As reported earlier [1], a high pressure electronically controlled accumulator injector using a diamond compact insert nozzle was developed for this project. The improved reliability and durability of this new FIE allowed for an improved and more thorough study of combustion of CWS fuel in a diesel engine. It was decided to include a diesel pilot fuel injector in the combustion system mainly due to engine start and low load operation needs. BKM, Inc. of San Diego, CA was contracted to develop the electronic diesel fuel pilot/starting FIE for the research engine. As a result, the experimental combustion study was very much facilitated due to the ability of changing pilot/CWS injection timings and quantities without having to stop the engine. Other parameters studied included combustion chamber configuration (by changing CWS fuel injector nozzle hole number/shape/angle), as well as injection pressure. The initial phase of this combustion study is now complete. The results have been adopted into the design of a 12 cylinder engine FIE, to be tested in 1992. This paper summarizes the main findings of this study.

  18. Combustion of dense streams of coal particles. Quarterly progress report No. 9, August 29, 1992--November 28, 1992

    SciTech Connect

    Annamalai, K.

    1992-12-31

    Ignition of the high volatile isolated coal particles in vitiated environment seems to occur heterogeneously at the leading edge of the particle. Volatiles are observed to be ejected upward as jets in the direction of the convective flow but only after heterogeneous ignition. The volatiles burn in the gas phase homogeneously and form a wake flame; a black inner zone (unburned volatile) is formed (see Fig.A.3 for many common characteristics of isolated flames).Intermittent volatile ignition and combustion are observed to occur during the combustion process for a few of the isolated particle combustion experiments on high volatile non-swelling coal. The medium volatile coal particles ignite faster than the high volatile coal; but the intermittent ignition is not observed. The low volatile isolated coal particles combust in shorter time. The isolated char particles ignite at the surface of the particle heterogeneously with little volatile ejected, yet are not sufficient to form a volatile flame, resulting in a subsequent heterogeneous combustion. A group flame is formed for the two-particle arrays at closer interparticle spacing (Fig.A.4). Also, intermittent ignition does not occur for the high volatile particles when the two particles are at farther distances which suggests that radiation interaction between the particles might be occurring. However this conclusion is purely speculative. The char arrays experience heterogeneous ignition at the leading edge; combustion proceeds heterogeneously.

  19. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2001-08-01

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. For the Third Quarter of this project we present our data on trace metal partitioning obtained from combustion of MSS and Gas, MSS and Coal and Coal and Gas alone.

  20. Mercury stable isotope signatures of world coal deposits and historical coal combustion emissions.

    PubMed

    Sun, Ruoyu; Sonke, Jeroen E; Heimbürger, Lars-Eric; Belkin, Harvey E; Liu, Guijian; Shome, Debasish; Cukrowska, Ewa; Liousse, Catherine; Pokrovsky, Oleg S; Streets, David G

    2014-07-01

    Mercury (Hg) emissions from coal combustion contribute approximately half of anthropogenic Hg emissions to the atmosphere. With the implementation of the first legally binding UNEP treaty aimed at reducing anthropogenic Hg emissions, the identification and traceability of Hg emissions from different countries/regions are critically important. Here, we present a comprehensive world coal Hg stable isotope database including 108 new coal samples from major coal-producing deposits in South Africa, China, Europe, India, Indonesia, Mongolia, former USSR, and the U.S. A 4.7‰ range in δ(202)Hg (-3.9 to 0.8‰) and a 1‰ range in Δ(199)Hg (-0.6 to 0.4‰) are observed. Fourteen (p < 0.05) to 17 (p < 0.1) of the 28 pairwise comparisons between eight global regions are statistically distinguishable on the basis of δ(202)Hg, Δ(199)Hg or both, highlighting the potential application of Hg isotope signatures to coal Hg emissions tracing. A revised coal combustion Hg isotope fractionation model is presented, and suggests that gaseous elemental coal Hg emissions are enriched in the heavier Hg isotopes relative to oxidized forms of emitted Hg. The model explains to first order the published δ(202)Hg observations on near-field Hg deposition from a power plant and global scale atmospheric gaseous Hg. Yet, model uncertainties appear too large at present to permit straightforward Hg isotope source identification of atmospheric forms of Hg. Finally, global historical (1850-2008) coal Hg isotope emission curves were modeled and indicate modern-day mean δ(202)Hg and Δ(199)Hg values for bulk coal emissions of -1.2 ± 0.5‰ (1SD) and 0.05 ± 0.06‰ (1SD).

  1. Preparation and combustion of high ash coal tailing slurry

    SciTech Connect

    Zhang Ziping; Zhang Wenfu; Fu Xiaoheng; Wang Zuna; Li Hui

    1998-12-31

    Flotation tailings from a coal preparation plant are known for their high ash, low heating value, high moisture content even after thickening and filtration, and difficult handability. However, they can be easily converted into a slurry fuel for boilers. Two flotation tailings, containing ash of 31.89% and 41.87% respectively, have been converted into slurry fuel with the following properties: solid content being 70.4% and 74.4% respectively; low heating value, 13,694kj/kg and 10,970kj/kg; and viscosity, 379 mPa.s and 180 mPa.s at a shear rate of 100s{sup {minus}1}. An eccentric slant jet coal slurry burner was installed at the boiler. Slurry atomizing nozzle operated at low pressure. Both slurries gave stable combustion without supporting fuel under the condition of cool air supply. A new way of flotation tailing utilization was demonstrated. China has more than 200 coal preparation plants washing more than 300 million tons of coal annually. These preparation plants generate more than 10 million tons of tailing annually, most of which is not currently being used, causing great environmental pollution and waste management difficulties for the enterprises. Comprehensive utilization of coal washer tailings is one of the key issues of environmental protection and energy saving in China.

  2. Integrating coal combustion and red mud sintering at an alumina refinery

    NASA Astrophysics Data System (ADS)

    Rayzman, Viktor L.; Filipovich, Igor K.

    1999-08-01

    The fuel cost at an alumina refinery can be significantly reduced by shifting steam generation from gas or oil to coal use. The sorbent that can be applied for the cleaning of fuel gases is a regular red mud copiously dumped at alumina refineries. It is possible to combine coal combustion and red mud low-temperature sintering to recover remaining alumina and caustic from a red mud. The integrated technology, based on a combination of known processes, will provide advantages over other methods that are currently being used.

  3. Coal cleaning process

    SciTech Connect

    Kindig, J.K.

    1994-01-11

    Fine particle coal is beneficiated in specially designed dense medium cyclones to improve particle acceleration and enhance separation efficiency. Raw coal feed is first sized to remove fine coal particles. The coarse fraction is then separated into clean coal, middlings, and refuse. Middlings are comminuted for beneficiation with the fine fraction. The fine fraction is deslimed in a countercurrent cyclone circuit and then separated as multiple fractions of different size specifications in dense medium cyclones. The dense medium contains ultra-fine magnetite particles of a narrow size distribution which aid separation and improves magnetite recovery. Magnetite is recovered from each separated fraction independently, with non-magnetic effluent water from one fraction diluting feed to a smaller-size fraction, and improving both overall coal and magnetite recovery. Magnetite recovery is in specially designed recovery units, based on particle size, with final separation in a rougher-cleaner-scavenger circuit of magnetic drum separators incorporating a high strength rare earth magnet. 12 figs.

  4. Biomass gasification chars for mercury capture from a simulated flue gas of coal combustion.

    PubMed

    Fuente-Cuesta, A; Diaz-Somoano, M; Lopez-Anton, M A; Cieplik, M; Fierro, J L G; Martínez-Tarazona, M R

    2012-05-15

    The combustion of coal can result in trace elements, such as mercury, being released from power stations with potentially harmful effects for both human health and the environment. Research is ongoing to develop cost-effective and efficient control technologies for mercury removal from coal-fired power plants, the largest source of anthropogenic mercury emissions. A number of activated carbon sorbents have been demonstrated to be effective for mercury retention in coal combustion power plants. However, more economic alternatives need to be developed. Raw biomass gasification chars could serve as low-cost sorbents for capturing mercury since they are sub-products generated during a thermal conversion process. The aim of this study was to evaluate different biomass gasification chars as mercury sorbents in a simulated coal combustion flue gas. The results were compared with those obtained using a commercial activated carbon. Chars from a mixture of paper and plastic waste showed the highest retention capacity. It was found that not only a high carbon content and a well developed microporosity but also a high chlorine content and a high aluminium content improved the mercury retention capacity of biomass gasification chars. No relationship could be inferred between the surface oxygen functional groups and mercury retention in the char samples evaluated. PMID:22325640

  5. Transformations of inorganic coal constituents in combustion systems. Volume 1, sections 1--5: Final report

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A.; Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M.; Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L.; Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A.

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles? What determines their composition? Whether or not particles deposit? How combustion conditions, including reactor size, affect these processes? remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

  6. Biomass gasification chars for mercury capture from a simulated flue gas of coal combustion.

    PubMed

    Fuente-Cuesta, A; Diaz-Somoano, M; Lopez-Anton, M A; Cieplik, M; Fierro, J L G; Martínez-Tarazona, M R

    2012-05-15

    The combustion of coal can result in trace elements, such as mercury, being released from power stations with potentially harmful effects for both human health and the environment. Research is ongoing to develop cost-effective and efficient control technologies for mercury removal from coal-fired power plants, the largest source of anthropogenic mercury emissions. A number of activated carbon sorbents have been demonstrated to be effective for mercury retention in coal combustion power plants. However, more economic alternatives need to be developed. Raw biomass gasification chars could serve as low-cost sorbents for capturing mercury since they are sub-products generated during a thermal conversion process. The aim of this study was to evaluate different biomass gasification chars as mercury sorbents in a simulated coal combustion flue gas. The results were compared with those obtained using a commercial activated carbon. Chars from a mixture of paper and plastic waste showed the highest retention capacity. It was found that not only a high carbon content and a well developed microporosity but also a high chlorine content and a high aluminium content improved the mercury retention capacity of biomass gasification chars. No relationship could be inferred between the surface oxygen functional groups and mercury retention in the char samples evaluated.

  7. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-01

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification.

  8. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-01

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification. PMID:26897573

  9. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  10. Process for low mercury coal

    DOEpatents

    Merriam, N.W.; Grimes, R.W.; Tweed, R.E.

    1995-04-04

    A process is described for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal. 4 figures.

  11. Process for low mercury coal

    DOEpatents

    Merriam, Norman W.; Grimes, R. William; Tweed, Robert E.

    1995-01-01

    A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

  12. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2003-01-31

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. Previous research results have demonstrated that the inhalation of coal/MSS ash particles cause an increase in lung permeability than coal ash particles alone. Elemental analysis of the coal/MSS ash particles showed that Zn was more abundant in these ash particles than the ash particles of coal ash alone.

  13. Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

    SciTech Connect

    Adams, Bradley; Davis, Kevin; Senior, Constance; Shim, Hong Shim; Otten, Brydger; Fry, Andrew; Wendt, Jost; Eddings, Eric; Paschedag, Alan; Shaddix, Christopher; Cox, William; Tree, Dale

    2013-09-30

    Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

  14. EFFECTS OF COFIRING LIGNIN AND BIOSOLIDS WITH COAL ON FIRESIDE PERFORMANCE AND COMBUSTION PRODUCTS

    SciTech Connect

    Kevin C. Galbreath

    2002-08-01

    Lignin, derived from municipal solid waste and biosolid feedstocks using Masada Resource Group's patented CES OxyNol{trademark} process, and acidified biosolids were evaluated as supplemental fuels with coal for producing steam and electricity. Tests were conducted in a pilot-scale (550,000-Btu/hr [580-MJ/hr]) combustion system to evaluate the effects of coal characteristics, blend mixture (on a dry wt% basis) and furnace exit gas temperature (FEGT) on boiler heat-exchange surface slagging and fouling, NO{sub x} and SO{sub x} production, fly ash characteristics, and combustion efficiency. The effects of blending lignin and acidified biosolids with coal on fuel handling and pulverization characteristics were also addressed. An 80 wt% Colorado--20 wt% subbituminous Powder River Basin coal blend from the Tennessee Valley Authority Colbert Steam Plant, hereafter referred to as the Colbert coal, and a bituminous Pittsburgh No. 8 coal were tested. The lignin and acidified biosolids were characterized by possessing higher moisture content and lower carbon, hydrogen, and heating values relative to the coals. Ash contents of the fuels were similar. The lignin also possessed higher concentrations of TiO{sub 2}, CaO, and SO{sub 3} and lower concentrations of SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, K{sub 2}O, and N relative to the coals. The sulfur content of lignin could be reduced through a more thorough washing and drying of the lignin in an efficient commercial-scale dewatering device. Acidified biosolids were distinguished by higher concentrations of P{sub 2}O{sub 5} and MgO and lower SiO{sub 2} and Al{sub 2}O{sub 3} relative to the other fuels. Trace element concentrations, especially for Cr, Pb, Hg, and Ni, were generally greater in the lignin and acidified biosolid fuels relative to the Colbert coal. Maximum trace element emission factors were calculated for 95:5 Colbert coal--lignin and 90:5:5 Colbert coal--lignin--acidified biosolid blends and compared to U

  15. Method for increasing steam decomposition in a coal gasification process

    DOEpatents

    Wilson, M.W.

    1987-03-23

    The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water- splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

  16. Method for increasing steam decomposition in a coal gasification process

    DOEpatents

    Wilson, Marvin W.

    1988-01-01

    The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water-splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

  17. Removal of mercury from coal via a microbial pretreatment process

    DOEpatents

    Borole, Abhijeet P.; Hamilton, Choo Y.

    2011-08-16

    A process for the removal of mercury from coal prior to combustion is disclosed. The process is based on use of microorganisms to oxidize iron, sulfur and other species binding mercury within the coal, followed by volatilization of mercury by the microorganisms. The microorganisms are from a class of iron and/or sulfur oxidizing bacteria. The process involves contacting coal with the bacteria in a batch or continuous manner. The mercury is first solubilized from the coal, followed by microbial reduction to elemental mercury, which is stripped off by sparging gas and captured by a mercury recovery unit, giving mercury-free coal. The mercury can be recovered in pure form from the sorbents via additional processing.

  18. Preliminary results of pre-combustion removal of mercury, arsenic, and selenium from coal by dry magnetic separation

    SciTech Connect

    Oder, R.R.; Jamison, R.E.; Brandner, E.D.

    1999-07-01

    The authors report the results of preliminary measurements of pre-combustion separation of major metal oxides and trace elements from coal by dry magnetic separation. The measurements have been made as part of ETCi's development of MagMill{trademark} technology for removing mineral matter from coal at the pulverizer at the front end of a coal fired power plant. The technology is specific to separation of mercury, arsenic, and selenium because of their associations with iron pyrites in coal. Measurements were made on a suite of five Eastern US and five Illinois Basin bituminous rank coals prepared at 8 Mesh topsize and processed as 8 Mesh by zero fractions through a dry Para Trap Magnetic Separator. Measurements of major metals and trace elements were made on the feed coal, the magnetic refuse fraction and the magnetic clean coal product. The range of weight recoveries measured for 13 of the trace elements for the suite of coals indicates a significant potential for pre-combustion removal of trace elements and especially for mercury, selenium, and arsenic by dry magnetic methods. While these three elements are important because they are considered hazardous air pollutant precursors, pre-combustion removal of arsenic is especially important because of its role in poisoning catalysts used in emerging SO{sub x} and NO{sub x} control technologies.

  19. On-Line Analysis and Kinetic Behavior of Arsenic Release during Coal Combustion and Pyrolysis.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Dai, Jinxin

    2015-11-17

    The kinetic behavior of arsenic (As) release during coal combustion and pyrolysis in a fluidized bed was investigated by applying an on-line analysis system of trace elements in flue gas. This system, based on inductively coupled plasma optical emission spectroscopy (ICP-OES), was developed to measure trace elements concentrations in flue gas quantitatively and continuously. Obvious variations of arsenic concentration in flue gas were observed during coal combustion and pyrolysis, indicating strong influences of atmosphere and temperature on arsenic release behavior. Kinetic laws governing the arsenic release during coal combustion and pyrolysis were determined based on the results of instantaneous arsenic concentration in flue gas. A second-order kinetic law was determined for arsenic release during coal combustion, and the arsenic release during coal pyrolysis followed a fourth-order kinetic law. The results showed that the arsenic release rate during coal pyrolysis was faster than that during coal combustion. Thermodynamic calculations were carried out to identify the forms of arsenic in vapor and solid phases during coal combustion and pyrolysis, respectively. Ca3(AsO4)2 and Ca(AsO2)2 are the possible species resulting from As-Ca interaction during coal combustion. Ca(AsO2)2 is the most probable species during coal pyrolysis.

  20. On-Line Analysis and Kinetic Behavior of Arsenic Release during Coal Combustion and Pyrolysis.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Dai, Jinxin

    2015-11-17

    The kinetic behavior of arsenic (As) release during coal combustion and pyrolysis in a fluidized bed was investigated by applying an on-line analysis system of trace elements in flue gas. This system, based on inductively coupled plasma optical emission spectroscopy (ICP-OES), was developed to measure trace elements concentrations in flue gas quantitatively and continuously. Obvious variations of arsenic concentration in flue gas were observed during coal combustion and pyrolysis, indicating strong influences of atmosphere and temperature on arsenic release behavior. Kinetic laws governing the arsenic release during coal combustion and pyrolysis were determined based on the results of instantaneous arsenic concentration in flue gas. A second-order kinetic law was determined for arsenic release during coal combustion, and the arsenic release during coal pyrolysis followed a fourth-order kinetic law. The results showed that the arsenic release rate during coal pyrolysis was faster than that during coal combustion. Thermodynamic calculations were carried out to identify the forms of arsenic in vapor and solid phases during coal combustion and pyrolysis, respectively. Ca3(AsO4)2 and Ca(AsO2)2 are the possible species resulting from As-Ca interaction during coal combustion. Ca(AsO2)2 is the most probable species during coal pyrolysis. PMID:26488499

  1. Measurement and modeling of advanced coal conversion processes, Volume III

    SciTech Connect

    Ghani, M.U.; Hobbs, M.L.; Hamblen, D.G.

    1993-08-01

    A generalized one-dimensional, heterogeneous, steady-state, fixed-bed model for coal gasification and combustion is presented. The model, FBED-1, is a design and analysis tool that can be used to simulate a variety of gasification, devolatilization, and combustion processes. The model considers separate gas and solid temperatures, axially variable solid and gas flow rates, variable bed void fraction, coal drying, devolatilization based on chemical functional group composition, depolymerization, vaporization and crosslinking, oxidation, and gasification of char, and partial equilibrium in the gas phase.

  2. Metallic species derived from fluidized bed coal combustion. [59 references

    SciTech Connect

    Natusch, D.F.S.; Taylor, D.R.

    1980-01-01

    Samples of fly ash generated by the combustion of Montana Rosebud coal in an experimental 18 inch fluidized bed combustor were collected. The use of a heated cascade impactor permitted collection of size fractionated material that avoided condensation of volatile gases on the particles. Elemental concentration trends were determined as a function of size and temperature and the results compared to published reports for conventional power plants. The behavior of trace metals appears to be substantially different in the two systems due to lower operating temperatures and the addition of limestone to the fluidized bed. Corrosion of the impactor plates was observed at the highest temperature and lowest limestone feed rate sampled during the study. Data from the elemental concentration and leaching studies suggest that corrosion is most likely due to reactions involving sodium sulfate. However, it is concluded that corrosion is less of a potential problem in fluidized-bed systems than in conventional coal-fired systems.

  3. Release of mercury vapor from coal combustion ash.

    PubMed

    Heebink, Loreal V; Hassett, David J

    2002-08-01

    The long-term stability of Hg in coal combustion by-products (CCBs) was evaluated at ambient and near-ambient temperatures. Six CCB samples with atypically high levels of total Hg were selected for study assuming a greater potential for release of measurable amounts of Hg vapor. The samples selected included two fly ash samples from U.S. eastern bituminous coal, two fly ash samples from South African low-rank coal, one fly ash from Powder River Basin (PRB) subbituminous coal blended with petroleum coke, and one PRB subbituminous coal fly ash incorporated with flue gas desulfurization material. Air scrubbed of Hg was passed through compacted 100-g aliquots of each sample at 1 mL/min and vented to a gold-coated quartz trap to collect released Hg vapor. The samples were maintained at ambient and near-ambient (37 degrees C) temperatures. All samples released low-picogram levels of Hg after 90 days. No pattern was evident to link the total Hg content to the rate of release of Hg vapor. An average of 0.030 pg Hg/g CCB/day was released from the samples, which equates to 2.2 x 10(-8) lb Hg/ton CCB/year. If this were applied to a coal-fired power plant production of 200,000 tons of fly ash per year, there would be a maximum potential release of 0.0044 lb, or 2.00 g, of Hg per year. Experiments are continuing to determine long-term vapor release of Hg from CCBs. All samples have been set up in duplicate at ambient temperature with an improved apparatus to reevaluate results reported in this article.

  4. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shim-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexington

    1992-11-01

    This report contains the computer codes developed for the coal combustion project. In Subsection B.1 the FORTRAN code developed for the percolative fragmentation model (or the discrete model, since a char is expressed as a collection of discrete elements in a discrete space) is presented. In Subsection B.2 the code for the continuum model (thus named because mineral inclusions are distributed in a continuum space) is presented. A stereological model code developed to obtain the pore size distribution from a two-dimensional data is presented in Subsection B.3.

  5. Preparation and analyses of low-rank coals for combustion applications: Final report

    SciTech Connect

    Smit, F.J.; Maas, D.J.

    1986-10-01

    The preparation of low-ash and low-sodium micronized low-rank coal (LRC) fuels for test firing in a gas-turbine combustor module is described in this report. Four subbituminous coals and one lignite were examined for their amenability to the preparation of high-quality powder and coal-water slurry fuels (CSF). The data base included the proximate, ultimate, ash composition, trace element, heating value, and free swelling index determinations and the slurry rheology for the raw coals and for the same coals after various physical separations, chemical treatments and hydrothermal processing. Eagle Butte subbituminous coal from the Powder River Basin was selected for preparation of ''available-quality'' and ''improved-quality'' micronized powder and slurry fuels for the combustion tests. This coal was cleaned in a dense-medium separator for preparation of available-quality fuels. Two advanced beneficiation steps were added for preparation of improved-quality fuels. The additional steps were (1) acid treatment to remove sodium and soluble ash minerals and (2) hydrothermal processing at 330/sup 0/C to improve the heating value and the rheology of the CSF. Twenty-four hundred pounds (dry basis) of minus 30-micrometer fuel were prepared for the combustion testing. A conceptual design was developed and costed for a 650,000 tpy improved-quality micronized CSF plant fueling 100 MW of gas-turbine generating capacity. The plant would be located adjacent to a mine in northeastern Wyoming. The capital construction cost for the plant was estimated to be $86.9 million and the operating cost for the plant (including amortization) was projected to be $4.55 per million Btu (HHV), FOB plant. The operating cost could be reduced to $3.22/MBtu if the plant were scaled for 500 MW of generating capacity instead of 100 MW. 19 refs., 12 figs., 31 tabs.

  6. CHARACTERIZATION OF COAL COMBUSTION BY-PRODUCTS FOR THE RE-EVOLUTION OF MERCURY INTO ECOSYSTEMS

    SciTech Connect

    A.M. Schwalb; J.A. Withum

    2003-07-01

    There is some concern that mercury (Hg) in coal combustion by-products can be emitted into the environment during processing to other products, by volatilization or by dissolution into groundwater. This perception may limit the opportunities to use coal combustion by-products after disposal in recycle/reuse applications. In this program, CONSOL Energy Inc., Research & Development (CONSOL) is conducting a comprehensive sampling and analytical program to address this concern. The objective is to evaluate the potential for Hg emissions by leaching or volatilization, and to provide data that will allow a scientific assessment of the issue. The main activities for this quarter were: the re-volatilization study was continued; the literature review was updated; and the ground water study was continued.

  7. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    DOE PAGES

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; Lerch, Harry; Olea, Ricardo A.; Suitt, Stephen E.; Kolker, Allan

    2010-01-01

    Indoormore » air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM 2.5 concentration in 20 homes was 36.0  μ g/ m 3 . This is the first time that PM 2.5 has been quantified and characterized inside Navajo reservation residents' homes.« less

  8. Navajo coal combustion and respiratory health near Shiprock, New Mexico.

    PubMed

    Bunnell, Joseph E; Garcia, Linda V; Furst, Jill M; Lerch, Harry; Olea, Ricardo A; Suitt, Stephen E; Kolker, Allan

    2010-01-01

    Indoor air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM₂.₅ concentration in 20 homes was 36.0 μg/m³. This is the first time that PM₂.₅ has been quantified and characterized inside Navajo reservation residents' homes. PMID:20671946

  9. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    PubMed Central

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; Lerch, Harry; Olea, Ricardo A.; Suitt, Stephen E.; Kolker, Allan

    2010-01-01

    Indoor air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM2.5 concentration in 20 homes was 36.0 μg/m3. This is the first time that PM2.5 has been quantified and characterized inside Navajo reservation residents' homes. PMID:20671946

  10. Pilot-scale demonstration of the OSCAR process for high-temperature multipollutant control of coal combustion flue gas, using carbonated fly ash and mesoporous calcium carbonate

    SciTech Connect

    Gupta, H.; Thomas, T.J.; Park, A.H.A.; Iyer, M.V.; Gupta, P.; Agnihotri, R.; Jadhav, R.A.; Walker, H.W.; Weavers, L.K.; Butalia, T.; Fan, L.S.

    2007-07-15

    A pilot-scale study of the Ohio State Carbonation Ash Reactivation (OSCAR) process was performed to demonstrate the reactivity of two novel calcium-based sorbents toward sulfur and trace heavy metal (arsenic, selenium, and mercury) capture in the furnace sorbent injection (FSI) mode on a 0.365 m{sup 3}/s slipstream of a bituminous coal-fired stoker boiler. The sorbents were synthesized by bubbling CO{sub 2} to precipitate calcium carbonate (a) from the unreacted calcium present in the lime spray dryer ash and (b) from calcium hydroxide slurry that contained a negatively charged dispersant. The heterogeneous reaction between these sorbents and SO{sub 2} gas occurred under entrained flow conditions by injecting fine sorbent powders into the flue gas slipstream. The reacted sorbents were captured either in a hot cyclone (about 650{sup o}C) or in the relatively cooler downstream baghouse (about 230{sup o}C). The baghouse samples indicated about 90% toward sulfation and captured arsenic, selenium and mercury to 800 ppmw, 175 ppmw and 3.6 ppmw, respectively.

  11. Development and Testing of Industrial Scale Coal Fired Combustion System, Phase 3

    SciTech Connect

    Bert Zauderer

    1998-09-30

    Coal Tech Corp's mission is to develop, license & sell innovative, lowest cost, solid fuel fired power systems & total emission control processes using proprietary and patented technology for domestic and international markets. The present project 'DEVELOPMENT & TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3' on DOE Contract DE-AC22-91PC91162 was a key element in achieving this objective. The project consisted of five tasks that were divided into three phases. The first phase, 'Optimization of First Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor', consisted of three tasks, which are detailed in Appendix 'A' of this report. They were implemented in 1992 and 1993 at the first generation, 20 MMBtu/hour, combustor-boiler test site in Williamsport, PA. It consisted of substantial combustor modifications and coal-fired tests designed to improve the combustor's wall cooling, slag and ash management, automating of its operation, and correcting severe deficiencies in the coal feeding to the combustor. The need for these changes was indicated during the prior 900-hour test effort on this combustor that was conducted as part of the DOE Clean Coal Program. A combination of combustor changes, auxiliary equipment changes, sophisticated multi-dimensional combustion analysis, computer controlled automation, and series of single and double day shift tests totaling about 300 hours, either resolved these operational issues or indicated that further corrective changes were needed in the combustor design. The key result from both analyses and tests was that the combustor must be substantially lengthened to maximize combustion efficiency and sharply increase slag retention in the combustor. A measure of the success of these modifications was realized in the third phase of this project, consisting of task 5 entitled: 'Site Demonstration with the Second Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor'. The details of the task 5 effort are

  12. Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

    EPA Science Inventory

    This paper/presentation is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practicall...

  13. Pyrolysis of Compositions of Mixtures of Combustible Shales and Brown Coals Deposited in Belarus

    NASA Astrophysics Data System (ADS)

    Lishtvan, I. I.; Dudarchik, V. M.; Kraiko, V. M.; Belova, Yu. V.

    2013-11-01

    This paper presents the results of investigating the pyrolysis of compositions of mixtures of brown coals and combustible shales in a close-packed and a moving layer and the yield dynamics of the pyrolysis gas and resin. A comparative analysis of the quality of pyrolysis products obtained from combustible shales and brown coal and from their mixtures has been performed.

  14. 75 FR 64974 - Notice of Data Availability on Coal Combustion Residual Surface Impoundments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... data posted in the docket for EPA's proposed rulemaking (75 FR 51434, August 20, 2010) on the Disposal of Coal Combustion Residuals from Electric Utilities. The Agency is seeking public comment on how, if... Coal Combustion Residual Surface Impoundments AGENCY: Environmental Protection Agency (EPA)....

  15. A Technique for Decreasing Reactivity of Coal Material to Suppress the Oxygen Absorption Process

    NASA Astrophysics Data System (ADS)

    Timofeeva, S. S.; Lugovtsova, N. Yu; Gubanova, A. R.

    2016-08-01

    The paper describes the mechanisms of self-ignition formation in coal liable to spontaneous combustion, on the basis of experimental works performed to analyze heat and mass transfer in the coal-air system. A new approach was developed to the coal self-heating suppression and thermodynamic control of the oxidation process. The influence of coal moisture content and thermal behaviour of air in the cooling process was studied during moisture evaporation.

  16. NO reduction in decoupling combustion of biomass and biomass-coal blend

    SciTech Connect

    Li Dong; Shiqiu Gao; Wenli Song; Jinghai Li; Guangwen Xu

    2009-01-15

    Biomass is a form of energy that is CO{sub 2}-neutral. However, NOx emissions in biomass combustion are often more than that of coal on equal heating-value basis. In this study, a technology called decoupling combustion was investigated to demonstrate how it reduces NO emissions in biomass and biomass-coal blend combustion. The decoupling combustion refers to a two-step combustion method, in which fuel pyrolysis and the burning of char and pyrolysis gas are separated and the gas burns out during its passage through the burning-char bed. Tests in a quartz dual-bed reactor demonstrated that, in decoupling combustion, NO emissions from biomass and biomass-coal blends were both less than those in traditional combustion and that NO emission from combustion of blends of biomass and coal decreased with increasing biomass percentage in the blend. Co-firing rice husk and coal in a 10 kW stove manufactured according to the decoupling combustion technology further confirmed that the decoupling combustion technology allows for truly low NO emission as well as high efficiency for burning biomass and biomass-coal blends, even in small-scale stoves and boilers. 22 refs., 6 figs., 1 tab.

  17. Structure-Based Predictive model for Coal Char Combustion.

    SciTech Connect

    Hurt, R.; Colo, J; Essenhigh, R.; Hadad, C; Stanley, E.

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  18. Co-combustion of sludge with coal or wood

    SciTech Connect

    Leckner, B.; Aamand, L.-E.

    2004-07-01

    There are several options for co-combustion of biomass or waste with coal. In all cases the fuel properties are decisive for the success of the arrangement: contents of volatile matter and of potential emission precursors, such as sulphur, nitrogen, chlorine, and heavy metals. The content of alkali in the mineral substance of the fuel is important because of the danger of fouling and corrosion. Research activities at Chalmers University of Technology include several aspects of the related problems areas. An example is given concerning emissions from co-combustion in circulating fluidized beds with coal or wood as base fuels, and with sewage sludge as additional fuel. Two aspects of the properties of sludge are studied: emissions of nitrogen and sulphur oxides as well as of chlorine, because the contents of the precursors to these emissions are high. The possibility of utilizing the phosphorus in sludge as a fertilizer is also discussed. The results show that emissions can be kept below existing emission limits if the fraction of sludge is sufficiently small but the concentration of trace elements in the sludge ash prevents the sludge from being used as a fertilizer. 15 refs., 9 figs., 2 tabs.

  19. Fluorosis caused by indoor coal combustion in China: discovery and progress.

    PubMed

    Zheng, Baoshan; Wu, Daishe; Wang, Binbin; Liu, Xiaojing; Wang, Mingshi; Wang, Aimin; Xiao, Guisen; Liu, Pugao; Finkelman, Robert B

    2007-04-01

    In this study, investigations into endemic fluorosis were conducted and fluorine concentration in environmental samples determined. In an indoor coal-combustion-type fluorosis area, local clay was used to mix with coal for indoor combustion. There are two key steps in the procedure of the indoor transition of fluorine: indoor wet corns and vegetables strongly absorbed fluorine from indoor air; and fluorine strongly accumulated in clay, which was mixed with coal for combustion. Therefore, with the increasing of the percentage of clay in the clay-mixed coal as well as corn in foodstuff, the ratio of fluorosis will be increased.

  20. Investigation on thermal and trace element characteristics during co-combustion biomass with coal gangue.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Fang, Ting; Lam, Paul Kwan Sing

    2015-01-01

    The thermochemical behaviors during co-combustion of coal gangue (CG), soybean stalk (SS), sawdust (SD) and their blends prepared at different ratios have been determined via thermogravimetric analysis. The simulate experiments in a fixed bed reactor were performed to investigate the partition behaviors of trace elements during co-combustion. The combustion profiles of biomass was more complicated than that of coal gangue. Ignition property and thermal reactivity of coal gangue could be enhanced by the addition of biomass. No interactions were observed between coal gangue and biomass during co-combustion. The volatilization ratios of trace elements decrease with the increasing proportions of biomass in the blends during co-combustion. Based on the results of heating value, activation energy, base/acid ratio and gaseous pollutant emissions, the blending ratio of 20-30% biomass content is regarded as optimum composition for blending and could be applied directly at current combustion application with few modifications.

  1. [Emission factors of polycyclic aromatic hydrocarbons (PAHs) in residential coal combustion and its influence factors].

    PubMed

    Hai, Ting-Ting; Chen, Ying-Jun; Wang, Yan; Tian, Chong-Guo; Lin, Tian

    2013-07-01

    As the emission source of polycyclic aromatic hydrocarbons (PAHs), domestic coal combustion has attracted increasing attention in China. According to the coal maturity, combustion form and stove type associated with domestic coal combustion, a large-size, full-flow dilution tunnel and fractional sampling system was employed to collect the emissions from five coals with various maturities, which were burned in the form of raw-coal-chunk (RCC)/honeycomb-coal-briquettes (HCB) in different residential stoves, and then the emission factors of PAHs (EF(PAHs)) were achieved. The results indicate that the EF(PAHs) of bituminous coal ranged from 1.1 mg x kg(-1) to 3.9 mg x kg(-1) for RCC and 2.5 mg x kg(-1) to 21. 1 mg x kg(-1) for HCB, and the anthracite EF(PAH8) were 0.2 mg x kg(-1) for RCC and 0.6 mg x kg(-1) for HCB, respectively. Among all the influence factors of emission factors of PAHs from domestic coal combustion, the maturity of coal played a major role, the range of variance reaching 1 to 2 orders of magnitude in coals with different maturity. Followed by the form of combustion (RCC/HCB), the EF(PAHs) of HCB was 2-6 times higher than that of RCC for the same geological maturity of the coal. The type of stove had little influence on EF(PAHs).

  2. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  3. Determination of halogens in coal after digestion using the microwave-induced combustion technique

    SciTech Connect

    Flores, E.M.M.; Mesko, M.F.; Moraes, D.P.; Pereira, J.S.F.; Mello, P.A.; Barin, J.S.; Knapp, G.

    2008-03-15

    The microwave-induced combustion (MIC) technique was applied for coal digestion and further determination of bromide, chloride, fluoride, and iodide by ion chromatography (IC). Samples (up to 500 mg) were combusted at 2 MPa of oxygen. Combustion was complete in less than 50 s, and analytes were absorbed in water or (NH{sub 4}){sub 2}CO{sub 3} solution. A reflux step was applied to improve analyte absorption. Accuracy was evaluated for Br, Cl, and F using certified reference coal and spiked samples for I. For Br, Cl, and F, the agreement was between 96 and 103% using 50 mmol L{sup -1} (NH{sub 4}){sub 2}CO{sub 3} as the absorbing solution and 5 min of reflux. With the use of the same conditions, the recoveries for I were better than 97%. Br, Cl, and I were also determined in MIC digests by inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, and F was determined by an ion-selective electrode with agreement better than 95% to the values obtained using IC. Temperature during combustion was higher than 1350 {sup o}C, and the residual carbon content was lower than 1%. With the use of the MIC technique, up to eight samples could be processed simultaneously, and a single absorbing solution was suitable for all analytes and determination techniques (limit of detection by IC was better than 3 {mu} g g{sup -1} for all halogens).

  4. Coal combustion science quarterly progress report, October--December 1992. Task 1, Coal char combustion [and] Task 2, Fate of mineral matter

    SciTech Connect

    Hardesty, D.R.; Hurt, R.H.; Baxter, L.L.

    1993-06-01

    In the Coal Combustion Laboratory (CCL) this quarter, controlled laboratory experiments were carried out to better understand the late stages of coal combustion and its relation to unburned carbon levels in fly ash. Optical in situ measurements were made during char combustion at high carbon conversions and the optical data were related to particle morphologies revealed by optical microscopy on samples extracted under the same conditions. Results of this work are reported in detail below. In the data presented below, we compare the fraction of alkali metal loss to that of the alkaline earth metals as a function of coal rank to draw conclusions about the mechanism of release for the latter. Figure 2.1 illustrates the fractional release of the major alkali and alkaline earth metals (Na, K, Ca, Mg) as a function of coal rank for a series of coals and for several coal blends. All data are derived from combustion experiments in Sandia`s Multifuel Combustor (MFC) and represent the average of three to eight experiments under conditions where the mass loss on a dry, ash-free (daf) basis exceeds 95 %. There are no missing data in the figure. The several coals with no indicated result exhibited no mass loss of the alkali or alkaline earth metals in our experiments. There is a clear rank dependence indicated by the data in Fig. 2.1, reflecting the mode of occurrence of the material in the coal.

  5. Mercury speciation and emissions from coal combustion in Guiyang, southwest China

    SciTech Connect

    Tang, S.L.; Feng, X.B.; Qiu, H.R.; Yin, G.X.; Yang, Z.C.

    2007-10-15

    Although China has been regarded as one of the largest anthropogenic mercury emission source with coal combustion, so far the actual measurements of Hg species and Hg emissions from the combustion and the capture of Hg in Chinese emission control devices were very limited. Aiming at Hg mercury species measurements in Guiyang, the capital city of Guizhou province in Southwest China, we studied flue gases of medium-to-small-sized industrial steam coal-firing boiler (10-30 t/h) with no control devices, medium-to-small-sized industrial steam coal-firing boiler with WFGD and large-scale coal combustion with ESPs using Ontario Hytro method. We obtained mercury emission factors of the three representative coal combustion and estimated mercury emissions in Guiyang in 2003, as well as the whole province from 1986 to 2002. Coal combustion in Guiyang emitted 1898 kg mercury to the atmosphere, of which 36% Hg is released from power plants, 41% from industrial coal combustion, and 23% from domestic users, and 267 kg is Hg{sup P}, 813 kg is Hg{sup 2+} and 817 kg is Hg{sup 0}. Mercury emission in Guizhou province increased sharply from 5.8 t in 1986 to 16.4 t in 2002. With the implementation of national economic strategy of China's Western Development, the annual mercury emission from coal combustion in the province is estimated to be about 32 t in 2015.

  6. Mercury speciation and emissions from coal combustion in Guiyang, Southwest China.

    PubMed

    Tang, Shunlin; Feng, Xinbin; Qiu, Jianrong; Yin, Guoxun; Yang, Zaichan

    2007-10-01

    Although China has been regarded as one of the largest anthropogenic mercury emission source with coal combustion, so far the actual measurements of Hg species and Hg emissions from the combustion and the capture of Hg in Chinese emission control devices were very limited. Aiming at Hg mercury species measurements in Guiyang, the capital city of Guizhou province in Southwest China, we studied flue gases of medium-to-small-sized industrial steam coal-firing boiler (10-30 t/h) with no control devices, medium-to-small-sized industrial steam coal-firing boiler with WFGD and large-scale coal combustion with ESPs using Ontario Hytro method. We obtained mercury emission factors of the three representative coal combustion and estimated mercury emissions in Guiyang in 2003, as well as the whole province from 1986 to 2002. Coal combustion in Guiyang emitted 1898 kg mercury to the atmosphere, of which 36% Hg is released from power plants, 41% from industrial coal combustion, and 23% from domestic users, and 267 kg is Hg(p), 813 kg is Hg(2+) and 817 kg is Hg0. Mercury emission in Guizhou province increased sharply from 5.8 t in 1986 to 16.4 t in 2002. With the implementation of national economic strategy of China's Western Development, the annual mercury emission from coal combustion in the province is estimated to be about 32 t in 2015.

  7. Recent advances in the use of synchrotron radiation for the analysis of coal combustion products

    SciTech Connect

    Manowitz, B.

    1995-11-01

    Two major coal combustion problems are the formation and build-up of slag deposits on heat transfer surfaces and the production and control of toxic species in coal combustion emissions. The use of synchrotron radiation for the analysis of coal combustion products can play a role in the better understanding of both these phenomena. An understanding of the chemical composition of such slags under boiler operating conditions and as a function of the mineral composition of various coals is one ultimate goal of this program. The principal constituents in the ash of many coals are the oxides of Si, Al, Fe, Ca, K, S, and Na. The analytical method required must be able to determine the functional forms of all these elements both in coal and in coal ash at elevated temperatures. One unique way of conducting these analyses is by x-ray spectroscopy.

  8. Cyclic flow underground coal gasification process

    DOEpatents

    Bissett, Larry A.

    1978-01-01

    The present invention is directed to a method of in situ coal gasification for providing the product gas with an enriched concentration of carbon monoxide. The method is practiced by establishing a pair of combustion zones in spaced-apart boreholes within a subterranean coal bed and then cyclically terminating the combustion in the first of the two zones to establish a forward burn in the coal bed so that while an exothermic reaction is occurring in the second combustion zone to provide CO.sub.2 -laden product gas, an endothermic CO-forming reaction is occurring in the first combustion zone between the CO.sub.2 -laden gas percolating thereinto and the hot carbon in the wall defining the first combustion zone to increase the concentration of CO in the product gas. When the endothermic reaction slows to a selected activity the roles of the combustion zones are reversed by re-establishing an exothermic combustion reaction in the first zone and terminating the combustion in the second zone.

  9. INVESTIGATION OF PRIMARY FINE PARTICULATE MATTER FROM COAL COMBUSTION BY COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY

    EPA Science Inventory

    The particle size distributions, morphologies, and chemical composition distributions of 14 coal fly ash (CFA) samples produced by the combustion of four western U.S. coals (two subbituminous, one lignite, and one bituminous) and three eastern U.S. coals (all bituminous) have bee...

  10. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Shah, N.; Huggins, F.E.; Huffman, G.P. )

    1991-09-01

    The technical objectives of this project are: (1) To define the partitioning of inorganic constituents associated with raw coal particles among products (including vapors, aerosols, and residual char/ash particles) formed under conditions representative of pulverized coal flames as a function of the specific (intrinsic and extrinsic) characteristics of the raw coal and the environment in which the transformations occur; and to characterize the resultant spectrum of products in detail. (2) To elucidate and quantify the fundamental processes (involving basic principles of physics, chemistry, thermodynamics) by which transformations of the inorganic constituents occur; and (3) to develop, based on the information required in (1) and (2), a tractable process'' model capable of predicting the significant features of the transformation process, most importantly, the nature and distribution of products. 26 refs., 151 figs., 51 tabs.

  11. Advances in measurements and simulation of gas-particle flows and coal combustion in burners/combustors

    NASA Astrophysics Data System (ADS)

    Zhou, L. X.

    2009-02-01

    Innovative coal combustors were developed, and measurement and simulation of gas-particle flows and coal combustion in such combustors were done in the Department of Engineering Mechanics, Tsinghua University. LDV/PDPA measurements are made to understand the behavior of turbulent gas-particle flows in coal combustors. Coal combustion test was done for the non-slagging cyclone coal combustor. The full two-fluid model developed by the present author was used to simulate turbulent gas-particle flows, coal combustion and NOx formation. It is found by measurements and simulation that the optimum design can give large-size recirculation zones for improving the combustion performance for all the combustors. The combustion test shows that the nonslagging coal combustor can burn 3-5mm coal particles with good combustion efficiency and low NO emission. Simulation in comparison with experiments indicates that the swirl number can significantly affect the NO formation in the swirl coal combustor.

  12. Coal combustion under conditions of blast furnace injection. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Crelling, J.C.; Case, E.R.

    1993-12-31

    A potentially new use for Illinois coal is as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. During the first phase of this project a number of the objectives were realized, specifically: (1) a blast furnace sampling system was developed and used successfully to collect samples inside an active furnace; (2) two sets of blast furnace samples were collected and petrographic analysis showed that char derived from injected coal is entering the reduction zone of the furnace; (3) a coal/char sampling probe was designed and fabricated; (4) the completion of a program of reactivity experiments on the injected coal char, blast furnace coke and Herrin No. 6 char. The results of the reactivity experiments indicate that Herrin No. 6 coal is similar or even superior to coals now being used in blast furnace injection and that additional testing is warranted.

  13. Combustion of coal chars in oxygen-enriched atmospheres

    SciTech Connect

    Bejarano, P.A.; Levendis, Y.A.

    2007-07-01

    This work pertains to the high-temperature combustion of pulverized coal chars under oxygen-enriched atmospheres. Single char particles were burned in a drop-tube furnace, electrically-heated to 1300-1500 K, in 21%, 50% and 100% O{sub 2}, in a balance of N{sub 2}. Their luminous combustion histories were observed with two-color ratio pyrometry. A solution of the Planckian ratio-pyrometry equation for temperature was implemented, extending on Wien's approximation. The temperature and time histories for 45-53 {mu}m bituminous chars experienced wide particle-to-particle disparity, and varied depending on oxygen mole fraction and furnace temperature. Average char surface temperatures increased from 1600-1800 K in air, to 2100-2300 K in 50% O-2, to 2300-2400 K in 100% O{sub 2}, at gas temperatures of 1300-1500 K, respectively. Combustion durations decreased from 25-45 ms in air, to 8-17 ms in 50% O{sub 2}, to 6-13 in 100% O{sub 2}. Thus, average particle temperatures increased by up to 45%, whereas burnout times decreased by up to 87% as combustion was progressively enriched in O{sub 2} until 100% was attained. The apparent and intrinsic reactivity of the chars burning at 1500 K gas temperature were found to increase by factors of to 8 and 35, respectively, as the oxygen mole fraction increased by a factor of five, from 21% to 100%.

  14. Process for coal liquefaction employing selective coal feed

    DOEpatents

    Hoover, David S.; Givens, Edwin N.

    1983-01-01

    An improved coal liquefaction process is provided whereby coal conversion is improved and yields of pentane soluble liquefaction products are increased. In this process, selected feed coal is pulverized and slurried with a process derived solvent, passed through a preheater and one or more dissolvers in the presence of hydrogen-rich gases at elevated temperatures and pressures, following which solids, including mineral ash and unconverted coal macerals, are separated from the condensed reactor effluent. The selected feed coals comprise washed coals having a substantial amount of mineral matter, preferably from about 25-75%, by weight, based upon run-of-mine coal, removed with at least 1.0% by weight of pyritic sulfur remaining and exhibiting vitrinite reflectance of less than about 0.70%.

  15. COMPARISON OF PARTICLE SIZE DISTRIBUTIONS AND ELEMENTAL PARTITIONING FROM THE COMBUSTION OF PULVERIZED COAL AND RESIDUAL FUEL OIL

    EPA Science Inventory

    The paper gives results of experimental efforts in which three coals and a residual fuel oil were combusted in three different systems simulating process and utility boilers. Particloe size distributions (PSDs) were determined using atmospheric and low-pressure impaction, electr...

  16. Advanced hot gas cleaning system for coal gasification processes

    NASA Astrophysics Data System (ADS)

    Newby, R. A.; Bannister, R. L.

    1994-04-01

    The United States electric industry is entering a period where growth and the aging of existing plants will mandate a decision on whether to repower, add capacity, or do both. The power generation cycle of choice, today, is the combined cycle that utilizes the Brayton and Rankine cycles. The combustion turbine in a combined cycle can be used in a repowering mode or in a greenfield plant installation. Today's fuel of choice for new combined cycle power generation is natural gas. However, due to a 300-year supply of coal within the United States, the fuel of the future will include coal. Westinghouse has supported the development of coal-fueled gas turbine technology over the past thirty years. Working with the U.S. Department of Energy and other organizations, Westinghouse is actively pursuing the development and commercialization of several coal-fueled processes. To protect the combustion turbine and environment from emissions generated during coal conversion (gasification/combustion) a gas cleanup system must be used. This paper reports on the status of fuel gas cleaning technology and describes the Westinghouse approach to developing an advanced hot gas cleaning system that contains component systems that remove particulate, sulfur, and alkali vapors. The basic process uses ceramic barrier filters for multiple cleaning functions.

  17. Naturally Occurring Radioactive Materials in Coals and Coal Combustion Residuals in the United States.

    PubMed

    Lauer, Nancy E; Hower, James C; Hsu-Kim, Heileen; Taggart, Ross K; Vengosh, Avner

    2015-09-15

    The distribution and enrichment of naturally occurring radioactive materials (NORM) in coal combustion residuals (CCRs) from different coal source basins have not been fully characterized in the United States. Here we provide a systematic analysis of the occurrence of NORM ((232)Th, (228)Ra, (238)U, (226)Ra, and (210)Pb) in coals and associated CCRs from the Illinois, Appalachian, and Powder River Basins. Illinois CCRs had the highest total Ra ((228)Ra + (226)Ra = 297 ± 46 Bq/kg) and the lowest (228)Ra/(226)Ra activity ratio (0.31 ± 0.09), followed by Appalachian CCRs (283 ± 34 Bq/kg; 0.67 ± 0.09), and Powder River CCRs (213 ± 21 Bq/kg; 0.79 ± 0.10). Total Ra and (228)Ra/(226)Ra variations in CCRs correspond to the U and Th concentrations and ash contents of their feed coals, and we show that these relationships can be used to predict total NORM concentrations in CCRs. We observed differential NORM volatility during combustion that results in (210)Pb enrichment and (210)Pb/(226)Ra ratios greater than 1 in most fly-ash samples. Overall, total NORM activities in CCRs are 7-10- and 3-5-fold higher than NORM activities in parent coals and average U.S. soil, respectively. This study lays the groundwork for future research related to the environmental and human health implications of CCR disposal and accidental release to the environment in the context of this elevated radioactivity.

  18. Granuflow and Mulled coal: Alternative processes for fine coal recovery

    SciTech Connect

    Davis, B.E.

    1999-07-01

    Granuflow and Mulled Coal were developed in parallel to enhance the ability to recover and process wet coal fines. There are some similarities in the processes; however, the end products are quite different. This paper will compare the properties of the two products prepared from the same coal and identify the unique properties of each. Criteria for selecting between the two processes, including cost, will be discussed.

  19. Behavior of sulfur and chlorine in coal during combustion and boiler corrosion

    SciTech Connect

    Chou, C.L.

    1991-01-01

    The purpose of this project is to conduct laboratory experiments to clarify the mechanism of boiler corrosion, which may lead to solving the corrosion problem associated with the utilization of Illinois' high-sulfur and high-chlorine coal. The kinetics of the release of sulfur and chlorine species during coal combustion is being determined in the laboratories using temperature-programmed pyrolysis coupled with quadrupole gas analysis (QGA) and thermogravimetric analysis in conjunction with Fourier transform infrared spectroscopy (FTIR). Samples of boiler deposits and ashes from different locations in boilers using Illinois coal will be analyzed for mineralogical and chemical compositions to understand the relations among deposit compositions, coal compositions, and the gaseous species in combustion gases. The relationship between the level of chlorine in Illinois coal and boiler corrosion will be studied by experiments with simulated combustion gases under combustion conditions. Reduction of sulfur and chloride concentrations in the flue gas using additives will also be evaluated.

  20. Evaluation of retrofitted post combustion NO{sub x} control technology on a wet bottom, coal-fired utility boiler

    SciTech Connect

    Huhmann, A.L.; Wallace, A.J.; Jantzen, T.; O`Leary, J.H.

    1996-12-31

    Public Service Electric and Gas Company (PSE&G) evaluated the effectiveness of post-combustion NO{sub x} control technologies on a wet-bottomed, coal-fired utility boiler. The technologies studied were conventional urea-based SNCR, in-duct and air heater SCR, and a combination of SNCR and SCR. While SNCR and, to a limited extent, SCR have been used on coal-fired boilers, these processes had not been demonstrated on a unit with the same configuration as the wet-bottom, continuous stagging, pulverized coal furnaces operated at PSE&G`s Mercer Generating Station.

  1. JV Task 108 - Circulating Fluidized-Bed Combustion and Combustion Testing of Turkish Tufanbeyli Coal

    SciTech Connect

    Douglas Hajicek; Jay Gunderson; Ann Henderson; Stephen Sollom; Joshua Stanislowski

    2007-08-15

    Two combustion tests were performed at the Energy & Environmental Research Center (EERC) using Tufanbeyli coal from Turkey. The tests were performed in a circulating fluidized-bed combustor (CFBC) and a pulverized coal-fired furnace, referred to as the combustion test facility (CTF). One of the goals of the project was to determine the type of furnace best suited to this coal. The coal is high in moisture, ash, and sulfur and has a low heating value. Both the moisture and the sulfur proved problematic for the CTF tests. The fuel had to be dried to less than 37% moisture before it could be pulverized and further dried to about 25% moisture to allow more uniform feeding into the combustor. During some tests, water was injected into the furnace to simulate the level of flue gas moisture had the fuel been fed without drying. A spray dryer was used downstream of the baghouse to remove sufficient sulfur to meet the EERC emission standards permitted by the North Dakota Department of Health. In addition to a test matrix varying excess air, burner swirl, and load, two longer-term tests were performed to evaluate the fouling potential of the coal at two different temperatures. At the lower temperature (1051 C), very little ash was deposited on the probes, but deposition did occur on the walls upstream of the probe bank, forcing an early end to the test after 2 hours and 40 minutes of testing. At the higher temperature (1116 C), ash deposition on the probes was significant, resulting in termination of the test after only 40 minutes. The same coal was burned in the CFBC, but because the CFBC uses a larger size of material, it was able to feed this coal at a higher moisture content (average of 40.1%) compared to the CTF (ranging from 24.2% to 26.9%). Sulfur control was achieved with the addition of limestone to the bed, although the high calcium-to-sulfur rate required to reduce SO{sub 2} emissions resulted in heat loss (through limestone calcination) and additional ash

  2. The effect of coal combustion flue gas components on low-level chlorine speciation using EPA method 26A.

    PubMed

    Sun, J Q; Crocker, C R; Lillemoen, C M

    2000-06-01

    U.S. Environmental Protection Agency (EPA) Method 26A is the recommended procedure for capturing and speciating halogen (X2) and hydrogen halide (HX) stack emissions from combustion sources. Previous evaluation studies of Method 26A have focused primarily on hydrogen chloride (HCl) speciation. Capture efficiency, bias, and the potential interference of Cl2 at high levels (> 20 ppm [microgram/m3]) and NH4Cl in the flue gas stream have been investigated. It has been suggested that precise Cl2 measurement and accuracy in quantifying HX or X2 using Method 26A are difficult to achieve at Cl2 concentrations < 5 ppm; however, no performance data exist to support this. Coal contains low levels of Cl, in the range of 5-2000 ppmw, which results in the presence of HCl and Cl2 in the products of combustion. HCl is the predominant Cl compound formed in the high-temperature combustion process, and it persists in the gas as the products of combustion cool. Concentrations of Cl2 in coal combustion flue gas at stack temperatures typically do not exceed 5 ppm. For this research, bench-scale experiments using simulated combustion flue gas were designed to validate the ability of Method 26A to speciate low levels of Cl2 accurately. This paper presents the results of the bench-scale tests. The effect of various flue gas components is discussed. The results indicate that SO2 is the only component in coal combustion flue gas that has an appreciable effect on Cl2 distribution in Method 26A impingers, and that Method 26A cannot accurately speciate HCl and Cl2 in coal combustion flue gas without modification.

  3. Use of the GranuFlow Process in Coal Preparation Plants to Improve Energy Recovery and Reduce Coal Processing Wastes

    SciTech Connect

    Glenn A. Shirey; David J. Akers

    2005-12-31

    With the increasing use of screen-bowl centrifuges in today's fine coal cleaning circuits, a significant amount of low-ash, high-Btu coal can be lost during the dewatering step due to the difficulty in capturing coal of this size consist (< 100 mesh or 0.15mm). The GranuFlow{trademark} technology, developed and patented by an in-house research group at DOE-NETL, involves the addition of an emulsified mixture of high-molecular-weight hydrocarbons to a slurry of finesized coal before cleaning and/or mechanical dewatering. The binder selectively agglomerates the coal, but not the clays or other mineral matter. In practice, the binder is applied so as to contact the finest possible size fraction first (for example, froth flotation product) as agglomeration of this fraction produces the best result for a given concentration of binder. Increasing the size consist of the fine-sized coal stream reduces the loss of coal solids to the waste effluent streams from the screen bowl centrifuge circuit. In addition, the agglomerated coal dewaters better and is less dusty. The binder can also serve as a flotation conditioner and may provide freeze protection. The overall objective of the project is to generate all necessary information and data required to commercialize the GranuFlow{trademark} Technology. The technology was evaluated under full-scale operating conditions at three commercial coal preparation plants to determine operating performance and economics. The handling, storage, and combustion properties of the coal produced by this process were compared to untreated coal during a power plant combustion test.

  4. Thermally induced structural changes in coal combustion. Final report

    SciTech Connect

    Flagan, R.C.; Gavalas, G.R.

    1992-01-01

    The effects of the temperature-time history during coal devolitization and oxidation on the physical properties and the reactivity of resulting char were studied experimentally for temperatures and residence times typical of pulverized combustion. Experiments were also carried out at somewhat lower temperatures and correspondingly longer residence times. An electrically heated laminar flow reactor was used to generate char and measure the rates of oxidation at gas temperatures about 1600K. Partially oxidized chars were extracted and characterized by gas adsorption and mercury porosimetry, optical and scanning electron microscopy, and oxidation in a thermogravimetric analysis system (TGA). A different series of experiments was conducted using a quadrople electrodynamic balance. Single particles were suspended electrodynamically and heated by an infrared laser in an inert or oxygen-containing atmosphere. During the laser heating, measurements were taken of particle mass, size/shape, and temperature.

  5. Parametric study of submicron particulates from pulverized-coal combustion

    SciTech Connect

    Pennucci, J.; Greif, R.; Parsons, G.; Robben, F.; Sherman, P.

    1981-01-01

    Pulverized coal sieved through a 200 mesh screen (particle diameter <75 ..mu..) was entrained in an air/methane/oxygen mixture and burned in an enclosed bunsen type burner fitted with a chimney. Measurements were made of the number and size of the particles in the submicron range (100 A to 500 A) downstream of the chimney exit using a transmission electron microscope. Variations in flame temperature (1900 to 2500/sup 0/K), cooling rate (3500 to 8000/sup 0/K/sec) and oxygen concentration (equivalence ratio from .62 to .94) were made. Cold secondary air was injected at the chimney exit. Results showed a sharp peak in the particle size distribution at diameters below 200 A for high cooling rates at high initial temperatures, suggesting homogeneous condensation of vaporized ash. At lower cooling rates the peak shifts toward larger particles. It appears possible, therefore, to control particulate emissions by modification of combustion and heat transfer conditions.

  6. An efficient process for recovery of fine coal from tailings of coal washing plants

    SciTech Connect

    Cicek, T.; Cocen, I.; Engin, V.T.; Cengizler, H.

    2008-07-01

    Gravity concentration of hard lignites using conventional jigs and heavy media separation equipment is prone to produce coal-rich fine tailings. This study aims to establish a fine coal recovery process of very high efficiency at reasonable capital investment and operational costs. The technical feasibility to upgrade the properties of the predeslimed fine refuse of a lignite washing plant with 35.9% ash content was investigated by employing gravity separation methods. The laboratory tests carried out with the combination of shaking table and Mozley multi-gravity separator (MGS) revealed that the clean coal with 18% ash content on dry basis could be obtained with 58.9% clean coal recovery by the shaking table stage and 4.1% clean coal recovery by MGS stage, totaling to the sum of 63.0% clean coal recovery from a predeslimed feed. The combustible recovery and the organic efficiency of the shaking table + MGS combination were 79.5% and 95.5%, respectively. Based on the results of the study, a flow sheet of a high-efficiency fine coal recovery process was proposed, which is also applicable to the coal refuse pond slurry of a lignite washing plant.

  7. Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway

    SciTech Connect

    Shen, Y.S.; Maldonado, D.; Guo, B.Y.; Yu, A.B.; Austin, P.; Zulli, P.

    2009-12-15

    In this work, a numerical model is used to study the flow and coal combustion along the coal plume in a large-scale setting simulating the lance-blowpipe-tuyere-raceway region of a blast furnace. The model formulation is validated against the measurements in terms of burnout for both low and high volatile coals. The typical phenomena related to coal combustion along the coal plume are simulated and analyzed. The effects of some operational parameters on combustion behavior are also investigated. The results indicate that oxygen as a cooling gas gives a higher coal burnout than methane and air. The underlying mechanism of coal combustion is explored. It is shown that under the conditions examined, coal burnout strongly depends on the availability of oxygen and residence time. Moreover, the influences of two related issues, i.e. the treatment of volatile matter (VM) and geometric setting in modeling, are investigated. The results show that the predictions of final burnouts using three different VM treatments are just slightly different, but all comparable to the measurements. However, the influence of the geometric setting is not negligible when numerically examining the combustion of pulverized coal under blast furnace conditions.

  8. Theoretical principles of use of coal fractions with different densities for combustion

    SciTech Connect

    S.G. Gagarin; A.M. Gyul'maliev

    2009-02-15

    It is reasonable to complement the conventional preparation of steam coal involving the removal of ash components and pyritic sulfur by the isolation of the lightest organic fractions, which possess enhanced performance characteristics. These fractions are smoothly saleable both on the domestic and world markets for effective pulverized-coal combustion via new combustion technologies. Heavier (inertinite) fractions of the coal preparation concentrate marketed at lower prices can be considered appropriate fuel for burning in circulating fluidized-bed combustion systems. 13 refs., 5 figs., 4 tabs.

  9. Combustion characteristics of dry coal-powder-fueled adiabatic diesel engine: Final report

    SciTech Connect

    Kakwani, R.M.; Kamo, R.

    1989-01-01

    This report describes the progress and findings of a research program aimed at investigating the combustion characteristics of dry coal powder fueled diesel engine. During this program, significant achievements were made in overcoming many problems facing the coal-powder-fueled engine. The Thermal Ignition Combustion System (TICS) concept was used to enhance the combustion of coal powder fuel. The major coal-fueled engine test results and accomplishments are as follows: design, fabrication and engine testing of improved coal feed system for fumigation of coal powder to the intake air; design, fabrication and engine testing of the TICS chamber made from a superalloy material (Hastelloy X); design, fabrication and engine testing of wear resistant chrome oxide ceramic coated piston rings and cylinder liner; lubrication system was improved to separate coal particles from the contaminated lubricating oil; control of the ignition timing of fumigated coal powder by utilizing exhaust gas recirculation (EGR) and variable TICS chamber temperature; coal-fueled engine testing was conducted in two configurations: dual fuel (with diesel pilot) and 100% coal-fueled engine without diesel pilot or heated intake air; cold starting of the 100% coal-powder-fueled engine with a glow plug; and coal-fueled-engine was operated from 800 to 1800 rpm speed and idle to full load engine conditions.

  10. Direct coal liquefaction process

    DOEpatents

    Rindt, J.R.; Hetland, M.D.

    1993-10-26

    An improved multistep liquefaction process for organic carbonaceous mater which produces a virtually completely solvent-soluble carbonaceous liquid product. The solubilized product may be more amenable to further processing than liquid products produced by current methods. In the initial processing step, the finely divided organic carbonaceous material is treated with a hydrocarbonaceous pasting solvent containing from 10% and 100% by weight process-derived phenolic species at a temperature within the range of 300 C to 400 C for typically from 2 minutes to 120 minutes in the presence of a carbon monoxide reductant and an optional hydrogen sulfide reaction promoter in an amount ranging from 0 to 10% by weight of the moisture- and ash-free organic carbonaceous material fed to the system. As a result, hydrogen is generated via the water/gas shift reaction at a rate necessary to prevent condensation reactions. In a second step, the reaction product of the first step is hydrogenated.

  11. Direct coal liquefaction process

    DOEpatents

    Rindt, John R.; Hetland, Melanie D.

    1993-01-01

    An improved multistep liquefaction process for organic carbonaceous mater which produces a virtually completely solvent-soluble carbonaceous liquid product. The solubilized product may be more amenable to further processing than liquid products produced by current methods. In the initial processing step, the finely divided organic carbonaceous material is treated with a hydrocarbonaceous pasting solvent containing from 10% and 100% by weight process-derived phenolic species at a temperature within the range of 300.degree. C. to 400.degree. C. for typically from 2 minutes to 120 minutes in the presence of a carbon monoxide reductant and an optional hydrogen sulfide reaction promoter in an amount ranging from 0 to 10% by weight of the moisture- and ash-free organic carbonaceous material fed to the system. As a result, hydrogen is generated via the water/gas shift reaction at a rate necessary to prevent condensation reactions. In a second step, the reaction product of the first step is hydrogenated.

  12. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    Senior, C.L.; Huggins, F.E.; Huffman, G.P.; Shan, N.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Swenson, S.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.; Mroczkowski, S.; Helble, J.; Mamani-Paco, R.; Sterling, R.; Dunham, G.; Miller, S.

    2000-08-17

    The final program review meeting of Phase II was held on June 22 in Salt Lake City. The goals of the meeting were to present work in progress and to identify the remaining critical experiments or analyses, particularly those involving collaboration among various groups. The information presented at the meeting is summarized in this report. Remaining fixed bed, bench-scale experiments at EERC were discussed. There are more ash samples which can be run. Of particular interest are high carbon ash samples to be generated by the University of Arizona this summer and some ash-derived sorbents that EERC has evaluated on a different program. The use of separation techniques (electrostatic or magnetic) was also discussed as a way to understand the active components in the ash with respect to mercury. XAFS analysis of leached and unleached ash samples from the University of Arizona was given a high priority. In order to better understand the fixed bed test results, CCSEM and Moessbauer analyses of those ash samples need to be completed. Utah plans to analyze the ash from the single particle combustion experiments for those major elements not measured by INAA. USGS must still complete mercury analyses on the whole coals and leaching residues. Priorities for further work at the SHRIMP-RG facility include arsenic on ash surfaces and mercury in sulfide minerals. Moessbauer analyses of coal samples from the University of Utah were completed; samples from the top and bottom layers of containers of five different coals showed little oxidation of pyrite in the top relative to the bottom except for Wyodak.

  13. A study of on-line analysis of chlorine during coal combustion

    SciTech Connect

    Napier, J.; Heidbrink, J.; Keene, J.

    1996-12-31

    The behavior of chlorine during the combustion of coal was studied using TG-FTIR and TG-MS systems. Parameters of the coal samples studied included variations in chlorine content, rank, and mesh size. The identification of evolved gases at different temperatures indicated three mechanisms of HCl release. The first evolution of HCl was due to thermal effects, and corresponds to the release of HCl absorbed on pore walls of the coal. The second evolution of HCl is a function of coal rank, and represents a more tightly bound chlorine associated with the hydrated coal matrix. The third evolution of HCl is a result of inorganic chlorides in the coal.

  14. Preparation and combustion of coal-water fuel from the Sin Pun coal deposit, southern Thailand

    SciTech Connect

    1997-05-01

    In response to an inquiry by the Department of Mineral Resources in Thailand, the Energy & Environmental Research Center (EERC) prepared a program to assess the responsiveness of Sin Pun lignite to the temperature and pressure conditions of hot-water drying. The results indicate that drying made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 27 wt% for the raw coal to about 15 wt% for the hot-water-dried (HWD) coals. The energy density for a pumpable coal-water fuel (CWF) indicates an increase from 4500 to 6100 Btu/lb by hot-water drying. Approximately 650 lb of HWD Sin Pun CWF were fired in the EERC`s combustion test facility. The fuel burned extremely well, with no feed problems noted during the course of the test. Fouling and slagging deposits each indicated a very low rate of ash deposition, with only a dusty layer formed on the cooled metal surfaces. The combustor was operated at between 20% and 25% excess air, resulting in a flue gas SO{sub 2} concentration averaging approximately 6500 parts per million.

  15. Smog chamber study on the evolution of fume from residential coal combustion.

    PubMed

    Geng, Chunmei; Wang, Kun; Wang, Wei; Chen, Jianhua; Liu, Xiaoyu; Liu, Hongjie

    2012-01-01

    Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking, and emit considerable pollutants to the atmosphere because of no treatment of their exhaust, which can result in deteriorating local air quality. In this study, a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation. The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition, and then quickly decreased, indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants. There was evident shoulder peak around 10 min combustion for both THC and CO, revealing the emissions from vitrinite combustion. Additionally, another broad emission peak of CO after 30 min was also observed, which was ascribed to the incomplete combustion of the inertinite. Compared with THC and CO, there was only one emission peak for NOx, SO2 and particular matters at the beginning stage of combustion. The fume evolution with static chamber simulation indicated that evident consumption of SO2 and NOx as well as new particle formation were observed. The consumption rates for SO2 and NOx were about 3.44% hr(-1) and 3.68% hr(-1), the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour, and the increase of the diameter of accumulation mode particles was evident. The addition of isoprene to the diluted mixture of the fume could promote 03 and secondary particle formation.

  16. Hybrid Solvent-Membrane CO2 Capture: A Solvent/Membrane Hybrid Post-combustion CO2 Capture Process for Existing Coal-Fired Power Plants

    SciTech Connect

    2010-07-01

    IMPACCT Project: The University of Kentucky is developing a hybrid approach to capturing CO2 from the exhaust gas of coal-fired power plants. In the first, CO2 is removed as flue gas is passed through an aqueous ammonium-based solvent. In the second, carbon-rich solution from the CO2 absorber is passed through a membrane that is designed to selectively transport the bound carbon, enhancing its concentration on the permeate side. The team’s approach would combine the best of both membrane- and solventbased carbon capture technologies. Under the ARPA-E award, the team is enabling the membrane operation to be a drop-in solution.

  17. Mercury emissions from coal combustion in Silesia, analysis using geostatistics

    NASA Astrophysics Data System (ADS)

    Zasina, Damian; Zawadzki, Jaroslaw

    2015-04-01

    Data provided by the UNEP's report on mercury [1] shows that solid fuel combustion in significant source of mercury emission to air. Silesia, located in southwestern Poland, is notably affected by mercury emission due to being one of the most industrialized Polish regions: the place of coal mining, production of metals, stone mining, mineral quarrying and chemical industry. Moreover, Silesia is the region with high population density. People are exposed to severe risk of mercury emitted from both: industrial and domestic sources (i.e. small household furnaces). Small sources have significant contribution to total emission of mercury. Official and statistical analysis, including prepared for international purposes [2] did not provide data about spatial distribution of the mercury emitted to air, however number of analysis on Polish public power and energy sector had been prepared so far [3; 4]. The distribution of locations exposed for mercury emission from small domestic sources is interesting matter merging information from various sources: statistical, economical and environmental. This paper presents geostatistical approach to distibution of mercury emission from coal combustion. Analysed data organized in 2 independent levels: individual, bottom-up approach derived from national emission reporting system [5; 6] and top down - regional data calculated basing on official statistics [7]. Analysis, that will be presented, will include comparison of spatial distributions of mercury emission using data derived from sources mentioned above. Investigation will include three voivodeships of Poland: Lower Silesian, Opole (voivodeship) and Silesian using selected geostatistical methodologies including ordinary kriging [8]. References [1] UNEP. Global Mercury Assessment 2013: Sources, Emissions, Releases and Environmental Transport. UNEP Chemicals Branch, Geneva, Switzerland, 2013. [2] NCEM. Poland's Informative Inventory Report 2014. NCEM at the IEP-NRI, 2014. http

  18. Zinc Isotope Variability in Three Coal-Fired Power Plants: A Predictive Model for Determining Isotopic Fractionation during Combustion.

    PubMed

    Ochoa Gonzalez, R; Weiss, D

    2015-10-20

    The zinc (Zn) isotope compositions of feed materials and combustion byproducts were investigated in three different coal-fired power plants, and the results were used to develop a generalized model that can account for Zn isotopic fractionation during coal combustion. The isotope signatures in the coal (δ(66)ZnIRMM) ranged between +0.73 and +1.18‰, values that fall well within those previously determined for peat (+0.6 ±2.0‰). We therefore propose that the speciation of Zn in peat determines the isotope fingerprint in coal. All of the bottom ashes collected in these power plants were isotopically depleted in the heavy isotopes relative to the coals, with δ(66)ZnIRMM values ranging between +0.26‰ and +0.64‰. This suggests that the heavy isotopes, possibly associated with the organic matter of the coal, may be preferentially released into the vapor phase. The fly ash in all of these power plants was, in contrast, enriched in the heavy isotopes relative to coal. The signatures in the fly ash can be accounted for using a simple unidirectional fractionation model with isotope fractionation factors (αsolid-vapor) ranging between 1.0003 and 1.0007, and we suggest that condensation is the controlling process. The model proposed allows, once the isotope composition of the feed coal is known, the constraining of the Zn signatures in the byproducts. This will now enable the integration of Zn isotopes as a quantitative tool for the source apportionment of this metal from coal combustion in the atmosphere. PMID:26422061

  19. Zinc Isotope Variability in Three Coal-Fired Power Plants: A Predictive Model for Determining Isotopic Fractionation during Combustion.

    PubMed

    Ochoa Gonzalez, R; Weiss, D

    2015-10-20

    The zinc (Zn) isotope compositions of feed materials and combustion byproducts were investigated in three different coal-fired power plants, and the results were used to develop a generalized model that can account for Zn isotopic fractionation during coal combustion. The isotope signatures in the coal (δ(66)ZnIRMM) ranged between +0.73 and +1.18‰, values that fall well within those previously determined for peat (+0.6 ±2.0‰). We therefore propose that the speciation of Zn in peat determines the isotope fingerprint in coal. All of the bottom ashes collected in these power plants were isotopically depleted in the heavy isotopes relative to the coals, with δ(66)ZnIRMM values ranging between +0.26‰ and +0.64‰. This suggests that the heavy isotopes, possibly associated with the organic matter of the coal, may be preferentially released into the vapor phase. The fly ash in all of these power plants was, in contrast, enriched in the heavy isotopes relative to coal. The signatures in the fly ash can be accounted for using a simple unidirectional fractionation model with isotope fractionation factors (αsolid-vapor) ranging between 1.0003 and 1.0007, and we suggest that condensation is the controlling process. The model proposed allows, once the isotope composition of the feed coal is known, the constraining of the Zn signatures in the byproducts. This will now enable the integration of Zn isotopes as a quantitative tool for the source apportionment of this metal from coal combustion in the atmosphere.

  20. METAL PARTITIONING IN COMBUSTION PROCESSES

    EPA Science Inventory

    This article summarizes ongoing research efforts at the National Risk Management Research Laboratory of the U.S. Environmental Protection Agency examining [high temperature] metal behavior within combustion environments. The partitioning of non-volatile (Cr and Ni), semi-volatil...

  1. Coal Research

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Coal slurries are "clean" pulverized coal mixed with oil or water. Significant fuel savings can be realized when using coal slurries. Advanced Fuels Technology (AFT) utilized a COSMIC program, (Calculation of Complex Chemical Equilibrium Compositions), which provides specific capabilities for determining combustion products. The company has developed a cleaning process that removes much of the mineral sulphur and ash from the coals.

  2. Process for cleaning undeslimed coal

    SciTech Connect

    Wells, C.H.

    1983-09-20

    A process for cleaning undeslimed coal includes the steps of determining the scalar value of cross-correlation function of the measured values of the percent magnetics and the bulk specific gravity of a heavy media and coal slurry being fed to a cyclone, comparing the value to a set-point value determined after start-up when the recirculating suspension in the feed slurry is normally clean, and diverting at least a portion of the heavy media suspension that is separated from the underflow of the cyclone from being mixed with the feed coal slurry, to thereby correspondingly recycle the slime content of the feed slurry, and concurrently increasing the flow of cleaner heavy media suspension to the feed coal slurry until the cross-correlation function is brought up to the set-point value. Also disclosed is an embodiment of the process for cleaning coal, wherein the overflow from the cyclone is screened and screened solution is split between a first recycle loop for cleaning the suspension and the heavy media sump. Similarly, the underflow from the cyclone is screened and then split between a separate recycle loop and the heavy media sump. Suspension is diverted to the heavy media sump from one or both recycle cleaning loops as necessary. The remaining portions of the split suspension flows from the two screening devices are, in turn, respectively split between two further sumps and the heavy media sump, with more suspension coming from the cyclone overflow screen when cleaner suspension is indicated as being necessary by the aforesaid statistical analysis.

  3. Coal combustion under conditions of blast furnace injection. [Quarterly] technical report, 1 December 1993--28 February 1994

    SciTech Connect

    Crelling, J.C.

    1994-06-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter a sample of the feed coal that is being used for injection into the No. 7 Blast Furnace of Inland Steel has been analyzed petrographically and compared to both the Herrin No. 6 coal and Armco feed coal. Additional characterization is underway and an advanced program of pyrolysis and reactivity testing has been initiated.

  4. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2001-01-31

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end we shall use an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. For the First Quarter of this three year project work has centered around recruiting a graduate student to take responsibility for execution of portions of the research, and modifying the furnace and supporting equipment to allow the combustion of coal/MMS mixtures. We have readied the analytical panel for measuring NO{sub x} and other gaseous pollutants. We expect initial experiments for data gathering for coal/MSS mixtures to commence in the next Quarter.

  5. Partitioning of selected trace elements in coal combustion products from two coal-burning power plants in the United States

    USGS Publications Warehouse

    Swanson, Sharon M.; Engle, Mark A.; Ruppert, Leslie F.; Affolter, Ronald H.; Jones, Kevin B.

    2013-01-01

    Samples of feed coal (FC), bottom ash (BA), economizer fly ash (EFA), and fly ash (FA) were collected from power plants in the Central Appalachian basin and Colorado Plateau to determine the partitioning of As, Cr, Hg, Pb, and Se in coal combustion products (CCPs). The Appalachian plant burns a high-sulfur (about 3.9 wt.%) bituminous coal from the Upper Pennsylvanian Pittsburgh coal bed and operates with electrostatic precipitators (ESPs), with flue gas temperatures of about 163 °C in the ESPs. At this plant, As, Pb, Hg, and Se have the greatest median concentrations in FA samples, compared to BA and EFA. A mass balance (not including the FGD process) suggests that the following percentages of trace elements are captured in FA: As (48%), Cr (58%), Pb (54%), Se (20%), and Hg (2%). The relatively high temperatures of the flue gas in the ESPs and low amounts of unburned C in FA (0.5% loss-on-ignition for FA) may have led to the low amount of Hg captured in FA. The Colorado Plateau plant burns a blend of three low-S (about 0.74 wt.%) bituminous coals from the Upper Cretaceous Fruitland Formation and operates with fabric filters (FFs). Flue gas temperatures in the baghouses are about 104 °C. The elements As, Cr, Pb, Hg, and Se have the greatest median concentrations in the fine-grained fly ash product (FAP) produced by cyclone separators, compared to the other CCPs at this plant. The median concentration of Hg in FA (0.0983 ppm) at the Colorado Plateau plant is significantly higher than that for the Appalachian plant (0.0315 ppm); this higher concentration is related to the efficiency of FFs in Hg capture, the relatively low temperatures of flue gas in the baghouses (particularly in downstream compartments), and the amount of unburned C in FA (0.29% loss-on-ignition for FA).

  6. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    SciTech Connect

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1996-12-31

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  7. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, Darren J.; Bonk, Donald L.; Dowdy, Thomas E.

    1998-01-01

    Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  8. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1998-01-13

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

  9. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2001-05-04

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end we shall use an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined.

  10. Process simulation of a circulating fluidized bed coal combustor

    SciTech Connect

    Legros, R.; Sotudeh-Gharebaagh, R.; Paris, J.; Chaouki, J.; Preto, F.

    1995-12-31

    The focus of this work is the development of a process simulator for a Circulating Fluidized Bed coal Combustor (CFBC). The development of a simple comprehensive model for coal combustion in a CFBC is based on existing work reported in the literature. The model combines the hydrodynamic features of a CFBC riser with the different reaction steps involved during coal combustion, including the sulphur capture by limestone particles. The commercial process simulation program ASPEN PLUS was chosen as a framework for the development of the CFBC process simulator. ASPEN PLUS has been widely accepted in the chemical industry as a design tool because of its ability to simulate various chemical processes, including power generation cycles. In ASPEN PLUS, several ideal chemical reactor models involving solids are available for simulation purposes. The CFBC process simulator is constructed using several ASPEN PLUS unit operation blocks. The information required for each block is obtained from the combustion and hydrodynamic models, which are inserted into the simulation flowsheet as subroutines or internal programs. The resulting CFBC process simulator is used to predict the performance of the CFBC pilot plant at Energy Research laboratories, CANMET in Ottawa.

  11. Combustion characteristics of blends of lignite and bituminous coal with different binder materials

    SciTech Connect

    Haykiri-Acma, H.; Ersoy-Mericboyu, A.; Kuecuekbayrak, S.

    2000-05-01

    In this study, the combustion characteristics of blends of a Turkish lignite and a Siberian bituminous coal with and without binder materials were investigated. Sunflower shell, sawdust, and molasses were used as binder materials. The combustion curves of the coal and binder material samples and of the blends were obtained using differential thermal analysis (DTA). The differences observed in the DTA curves of the samples are discussed in detail.

  12. CFD investigation on the flow and combustion in a 300 MWe tangentially fired pulverized-coal furnace

    NASA Astrophysics Data System (ADS)

    Khaldi, Nawel; Chouari, Yoldoss; Mhiri, Hatem; Bournot, Philippe

    2016-09-01

    The characteristics of the flow, combustion and temperature in a 300 MWe tangentially fired pulverized-coal furnace are numerically studied using computational fluid dynamics. The mathematical model is based on a Eulerian description for the continuum phase and a Lagrangian description for coal particles. The combustion reaction scheme was modeled using eddy dissipation concept. The application of a proper turbulence model is mandatory to generate accurate predictions of flow and heat transfer during combustion. The current work presents a comparative study to identify the suitable turbulence model for tangentially fired furnace problem. Three turbulence models including the standard k-ɛ model, the RNG k-ɛ model and the Reynolds Stress model, RSM are examined. The predictions are compared with the published experimental data of Zheng et al. (Proc Combust Inst 29: 811-818, 2002). The RNG k-ɛ model proves to be the most suitable turbulence model, offering a satisfactory prediction of the velocity, temperature and species fields. The detailed results presented in this paper may enhance the understanding of complex flow patterns and combustion processes in tangentially fired pulverized-coal furnaces.

  13. Characteristics of particulate carbon emissions from real-world Chinese coal combustion

    SciTech Connect

    Yuanxun Zhang; James Jay Schauer; Yuanhang Zhang; Limin Zeng; Yongjie Wei; Yuan Liu; Min Shao

    2008-07-15

    Particulate matter emissions from a series of different Chinese coal combustion systems were collected and analyzed for elemental and organic carbon (EC, OC), and molecular markers. Emissions from both industrial boilers and residential stoves were investigated. The coal used in this study included anthracite, bituminite, and brown coal, as well as commonly used coal briquettes produced in China for residential coal combustion. Results show significant differences in the contribution of carbonaceous species to particulate mass emissions. Industrial boilers had much higher burn out of carbon yielding particulate matter emissions with much lower levels of OC, EC, and speciated organic compounds, while residential stoves had significantly higher emissions of carbonaceous particulate matter with emission rates of approximately 100 times higher than that of industrial boilers. Quantified organic compounds emitted from industrial boilers were dominated by oxygenated compounds, of which 46-68% were organic acids, whereas the dominate species quantified in the emissions from residential stoves were PAHs (38%) and n-alkanes (20%). An important observation was the fact that emission factors of PAHs and the distribution of hopanoids were different among the emissions from industrial and residential coal combustion even using the same coal for combustion. Although particulate matter emissions from industrial and residential combustion were different in many regards, picene was detected in all samples with detectable OC mass concentrations, which supports the use of this organic tracer for OC from all types of coal combustion. 17{alpha}(H),21{beta}(H)-29-norhopane was the predominant hopanoid in coal combustion emissions, which is different from mobile source emissions and may be used to distinguish emissions from these different fossil fuel sources. 32 refs., 4 figs., 1 tab.

  14. Energy recycling by co-combustion of coal and recovered paint solids from automobile paint operations

    SciTech Connect

    Achariya Suriyawong; Rogan Magee; Ken Peebles; Pratim Biswas

    2009-05-15

    This paper presents the results of an experimental study of particulate emission and the fate of 13 trace elements (arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), cobalt (Co), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), mercury (Hg), vanadium (V), and zinc (Zn)) during combustion tests of recovered paint solids (RPS) and coal. The emissions from combustions of coal or RPS alone were compared with those of co-combustion of RPS with subbituminous coal. The distribution/partitioning of these toxic elements between a coarse-mode ash (particle diameter (d{sub p}) > 0.5 {mu}m), a submicrometer-mode ash (d{sub p} < 0.5 {mu}m), and flue gases was also evaluated. Submicrometer particles generated by combustion of RPS alone were lower in concentration and smaller in size than that from combustion of coal. However, co-combustion of RPS and coal increased the formation of submicrometer-sized particles because of the higher reducing environment in the vicinity of burning particles and the higher volatile chlorine species. Hg was completely volatilized in all cases; however, the fraction in the oxidized state increased with co-combustion. Most trace elements, except Zn, were retained in ash during combustion of RPS alone. Mo was mostly retained in all samples. The behavior of elements, except Mn and Mo, varied depending on the fuel samples. As, Ba, Cr, Co, Cu, and Pb were vaporized to a greater extent from cocombustion of RPS and coal than from combustion of either fuel. Evidence of the enrichment of certain toxic elements in submicrometer particles has also been observed for As, Cd, Cr, Cu, and Ni during co-combustion. 27 refs., 6 figs., 5 tabs.

  15. Co-combustion of coal and solid waste (municipal and industrial solid wastes)

    SciTech Connect

    Ketlogetswe, C.

    1996-12-31

    This work determines the thermal characteristics of various mixtures of carpet waste as an illustrative solid waste. Generally the results revealed that combustion of a mixture of coal with carpet waste yields high fuel bed temperature, in comparison with the combustion of pure solid waste. High fuel bed temperatures of 1,340 C to 1,520 C obtained during the combustion of a mixture of coal with PVC carpet waste would be ideal for energy recovery. The fuel bed temperature of 1,290 C obtained during the combustion of 100% PVC carpet waste suggests that the combustion of general industrial solid waste may be expected to yield a fuel bed temperature of about 1,400 C which would be suitable for energy recovery in the form of power generation or steam generation for general use. The results also revealed that combustion of a mixture of coal and municipal solid waste may require 30% to 35% coal to achieve a fuel bed temperature of about 1,300 C. From economical viewpoint, the % of coal must be kept to a minimum, at least 20% coal or less.

  16. Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media

    USGS Publications Warehouse

    Darmody, R.G.; Green, W.P.; Dreher, G.B.

    1998-01-01

    Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasiblity of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3:FeS2 ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all mixtures. Tall fescue and sweet clover grew well in all the treatments, but birdsfoot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method.

  17. Catalyst for coal liquefaction process

    DOEpatents

    Huibers, Derk T. A.; Kang, Chia-Chen C.

    1984-01-01

    An improved catalyst for a coal liquefaction process; e.g., the H-Coal Process, for converting coal into liquid fuels, and where the conversion is carried out in an ebullated-catalyst-bed reactor wherein the coal contacts catalyst particles and is converted, in addition to liquid fuels, to gas and residual oil which includes preasphaltenes and asphaltenes. The improvement comprises a catalyst selected from the group consisting of the oxides of nickel molybdenum, cobalt molybdenum, cobalt tungsten, and nickel tungsten on a carrier of alumina, silica, or a combination of alumina and silica. The catalyst has a total pore volume of about 0.500 to about 0.900 cc/g and the pore volume comprises micropores, intermediate pores and macropores, the surface of the intermediate pores being sufficiently large to convert the preasphaltenes to asphaltenes and lighter molecules. The conversion of the asphaltenes takes place on the surface of micropores. The macropores are for metal deposition and to prevent catalyst agglomeration. The micropores have diameters between about 50 and about 200 angstroms (.ANG.) and comprise from about 50 to about 80% of the pore volume, whereas the intermediate pores have diameters between about 200 and 2000 angstroms (.ANG.) and comprise from about 10 to about 25% of the pore volume, and the macropores have diameters between about 2000 and about 10,000 angstroms (.ANG.) and comprise from about 10 to about 25% of the pore volume. The catalysts are further improved where they contain promoters. Such promoters include the oxides of vanadium, tungsten, copper, iron and barium, tin chloride, tin fluoride and rare earth metals.

  18. Combustion and gasification characteristics of chars from four commercially significant coals of different rank. Final report

    SciTech Connect

    Nsakala, N.Y.; Patel, R.L.; Lao, T.C.

    1982-09-01

    The combustion and gasification kinetics of four size graded coal chars were investigated experimentally in Combustion Engineering's Drop Tube Furnace System (DTFS). The chars were prepared in the DTFS from commercially significant coals representing a wide range of rank; these included a Pittsburgh No. 8 Seam hvAb coal, an Illinois No. 6 Seam hvCb coal, a Wyoming Sub C, and a Texas Lignite A. Additionally, a number of standard ASTM and special bench scale tests were performed on the coals and chars to characterize their physicochemical properties. Results showed that the lower rank coal chars were more reactive than the higher rank coal chars and that combustion reactions of chars were much faster than the corresponding gasification reactions. Fuel properties, temperature, and reactant gas partial pressure had a significant influence on both combustion and gasification, and particle size had a mild but discernible influence on gasification. Fuel reactivities were closely related to pore structure. Computer simulation of the combustion and gasification performances of the subject samples in the DTFS supported the experimental findings.

  19. [Regularity of flourine release from fluorine-rich coal combustion in the fluorine poisoning area].

    PubMed

    Yu, Jiang-ping; Feng, Fu-jian; Wang, Wu-yi; Luo, Kun-li; Chen, Dai-zhong; Bai, Guang-lu; Li, Yue; Zheng, Lai-yi; Bai, Ai-mei; Li, Ying

    2004-09-01

    Laboratory experiments and in situ measurements inside farmer's houses indicate that the fluorine concentration of indoor air was positively related with the fluorine content in the consumed coal (R = 0.612, P<0.01), but fluorine content in the coal had no effect on the release rate of coal fluorine under the usual combustion temperature of about 1000 degrees C. The release rate of coal fluorine varied versus combustion temperature ranging from 200 to 1200 degrees C, following a "S" curve pattern, increasing slowly under 300 to 700 degrees C, but quickly under 700 to 1000 degrees C, and then slowly again before finally reaching 100% under 1100 to 1200 degrees C, this curve can be fit by Logistic equation. The release rate of coal fluorine usually depends upon the existence status of fluorine and the chemical and mineral components of the coal. The fluorine in soft coal or anthracite from Guizhou is released more quickly than in bone coal from Southern Shanxi, with the former almost completely released under 1100 degrees C but the later almost completely released under 1200 degrees C. The combustion temperature of civil stoves is at most 1000 degrees C, under which averagely 86.9% of the fluorine in coal from Guizhou and 80.6% of that in bone coal from Southern Shanxi is released. PMID:15623020

  20. A Course in Fundamentals of Coal Utilization and Conversion Processes.

    ERIC Educational Resources Information Center

    Radovic, Ljubisa R.

    1985-01-01

    Describes the content, objectives, and requirements for a one-semester (30 20-hour sessions) graduate engineering course at the University of Concepcion, Chile. Major course topics include: structure and properties of coal; coal pyrolysis and carbonization; coal liquefaction; coal combustion and gasification; and economic and environmental…

  1. Seed regeneration processes for coal fired MHD power plants

    SciTech Connect

    Krumreich, B.M.

    1985-05-07

    Potassium carbonate seed is used to produce an electrically conducting gas required to generate electrical power in the open cycle coal fired MHD system. The seed can also serve to capture the sulfur released by the coal during combustion. Due to the high cost of the seed material, a large portion of the seed must be recycled for the MHD system to be economically feasible. Compiled information on the following processes for seed regeneration is presented: PERC; Formate; Modified Engel Precht; Econoseed; Aqueous Carbonate; Modified Tampella; and Westinghouse. In addition, a seed recycle system using a scrubber for flue gas desulfurization was studied.

  2. RELATIONSHIPS BETWEEN COMPOSITION AND PULMONARY TOXICITY OF PROTOTYPE PARTICLES FROM COAL COMBUSTION AND PYROLYSIS (MONTREAL, CANADA)

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  3. Relationships between composition and pulmonary toxicity of prototype particles from coal combustion and pyrolysis

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  4. VARIATION OF ELEMENT SPECIATION IN COAL COMBUSTION AEROSOLS WITH PARTICLE SIZE

    EPA Science Inventory

    The speciation of sulfur, iron and key trace elements (Cr, As, Se, Zn) in combustion ash aerosols has been examined as a function of size from experimental combustion units burning Utah and Illinois bituminous coals. Although predominantly present as sulfate, sulfur was also pre...

  5. Effects of calcium magnesium acetate on the combustion of coal-water slurries

    SciTech Connect

    Levendis, Y.A.

    1991-01-01

    The general objective of the project is to investigate the combustion behavior of single and multiple Coal-Water Fuel (CWF) particles burning at high temperature environments. Both uncatalyzed as well as catalyzed CWF drops with Calcium Magnesium Acetate (CMA) catalyst will be studies. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion.

  6. Geochemical Proxies for Enhanced Process Control of Underground Coal Gasification

    NASA Astrophysics Data System (ADS)

    Kronimus, A.; Koenen, M.; David, P.; Veld, H.; van Dijk, A.; van Bergen, F.

    2009-04-01

    Underground coal gasification (UCG) represents a strategy targeting at syngas production for fuel or power generation from in-situ coal seams. It is a promising technique for exploiting coal deposits as an energy source at locations not allowing conventional mining under economic conditions. Although the underlying concept has already been suggested in 1868 and has been later on implemented in a number of field trials and even at a commercial scale, UCG is still facing technological barriers, impeding its widespread application. Field UCG operations rely on injection wells enabling the ignition of the target seam and the supply with oxidants (air, O2) inducing combustion (oxidative conditions). The combustion process delivers the enthalpy required for endothermic hydrogen production under reduction prone conditions in some distance to the injection point. The produced hydrogen - usually accompanied by organic and inorganic carbon species, e.g. CH4, CO, and CO2 - can then be retrieved through a production well. In contrast to gasification of mined coal in furnaces, it is difficult to measure the combustion temperature directly during UCG operations. It is already known that geochemical parameters such as the relative production gas composition as well as its stable isotope signature are related to the combustion temperature and, consequently, can be used as temperature proxies. However, so far the general applicability of such relations has not been proven. In order to get corresponding insights with respect to coals of significantly different rank and origin, four powdered coal samples covering maturities ranging from Ro= 0.43% (lignite) to Ro= 3.39% (anthracite) have been gasified in laboratory experiments. The combustion temperature has been varied between 350 and 900 ˚ C, respectively. During gasification, the generated gas has been captured in a cryo-trap, dried and the carbon containing gas components have been catalytically oxidized to CO2. Thereafter, the

  7. Characterization of Coal Combustion Residues from Electric Utilities Using Wet Scrubbers for Multi-Pollutant Control

    EPA Science Inventory

    This report evaluates changes that may occur to coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants, which will reduce emissions from the flue gas stack by transferring pollutants to fly ash and other air pollution...

  8. ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS

    EPA Science Inventory

    In this study, the speciation of heavy metals such as arsenic, selenium, lead, zinc and mercury in coal combustion products (CCPs) was evaluated using sequential extraction procedures. Coal fly ash, bottom ash and flue gas desulphurization (FGD) sludge samples were used in the ex...

  9. Characterization of Coal Combustion Residues from Electric Utilities--Leaching and Characterization Data

    EPA Science Inventory

    This report evaluates changes in composition and constituent release by leaching that may occur to fly ash and other coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants. The addition of flue-gas desulfurization (FG...

  10. Process for fixed bed coal gasification

    DOEpatents

    Sadowski, Richard S.

    1992-01-01

    The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

  11. Advances in the shell coal gasification process

    SciTech Connect

    Doering, E.L.; Cremer, G.A.

    1995-12-31

    The Shell Coal Gasification Process (SCGP) is a dry-feed, oxygen-blown, entrained flow coal gasification process which has the capability to convert virtually any coal or petroleum coke into a clean medium Btu synthesis gas, or syngas, consisting predominantly of carbon monoxide and hydrogen. In SCGP, high pressure nitrogen or recycled syngas is used to pneumatically convey dried, pulverized coal to the gasifier. The coal enters the gasifier through diametrically opposed burners where it reacts with oxygen at temperatures in excess of 2500{degrees}F. The gasification temperature is maintained to ensure that the mineral matter in the coal is molten and will flow smoothly down the gasifier wall and out the slag tap. Gasification conditions are optimized, depending on coal properties, to achieve the highest coal to gas conversion efficiency, with minimum formation of undesirable byproducts.

  12. Phytostabilization of a landfill containing coal combustion waste.

    SciTech Connect

    Barton, Christopher; Marx, Donald; Adriano, Domy; Koo, Bon Jun; Newman, Lee; Czapka, Stephen; Blake, John

    2005-12-01

    The establishment of a vegetative cover to enhance evapotranspiration and control runoff and drainage was examined as a method for stabilizing a landfill containing coal combustion waste. Suitable plant species and pretreatment techniques in the form of amendments, tilling, and chemical stabilization were evaluated. A randomized plot design consisting of three subsurface treatments (blocks) and five surface amendments (treatments) was implemented. The three blocks included (1) ripping and compost amended, (2) ripping only, and (3) control. Surface treatments included (1) topsoil, (2) fly ash, (3) compost, (4) apatite, and (5) control. Inoculated loblolly (Pinus taeda) and Virginia (Pinus virginiana) pine trees were planted on each plot. After three growing seasons, certain treatments were shown to be favorable for the establishment of vegetation on the basin. Seedlings located on block A developed a rooting system that penetrated into the basin media without significant adverse effects to the plant. However, seedlings on blocks B and C displayed poor rooting conditions and high mortality, regardless of surface treatment. Pore-water samples from lysimeters in block C were characterized by high acidity, Fe, Mn, Al, sulfate, and traceelement concentrations. Water-quality characteristics of the topsoil plots in block A, however, conformed to regulatory protocols. A decrease in soil-moisture content was observed in the rooting zone of plots that were successfully revegetated, which suggests that the trees, in combination with the surface treatments, influenced the water balance by facilitating water loss through transpiration and thereby reducing the likelihood of unwanted surface runoff and/or drainage effluent.

  13. STUDIES OF THE SPONTANEOUS COMBUSTION OF LOW RANK COALS AND LIGNITES

    SciTech Connect

    Joseph M. Okoh; Joseph N.D. Dodoo

    2005-07-26

    Spontaneous combustion has always been a problem in coal utilization especially in the storage and transportation of coal. In the United States, approximately 11% of underground coal mine fires are attributed to spontaneous coal combustion. The incidence of such fires is expected to increase with increased consumption of lower rank coals. The cause is usually suspected to be the reabsorption of moisture and oxidation. To understand the mechanisms of spontaneous combustion this study was conducted to (1) define the initial and final products during the low temperature (10 to 60 C) oxidation of coal at different partial pressures of O{sub 2}, (2) determine the rate of oxidation, and (3) measure the reaction enthalpy. The reaction rate (R) and propensity towards spontaneous combustion were evaluated in terms of the initial rate method for the mass gained due to adsorbed O{sub 2}. Equipment that was used consisted of a FT-IR (Fourier Transform-Infrared Spectrometer, Perkin Elmer), an accelerated surface area porosimeter (ASAP, Micromeritics model 2010), thermogravimetric analyzer (TGA, Cahn Microbalance TG 121) and a differential scanning calorimeter (DSC, Q1000, thermal analysis instruments). Their combination yielded data that established a relation between adsorption of oxygen and reaction enthalpy. The head space/ gas chromatograph/ mass spectrometer system (HS/GC/MS) was used to identify volatiles evolved during oxidation. The coal samples used were Beulah lignite and Wyodak (sub-bituminous). Oxygen (O{sub 2}) absorption rates ranged from 0.202 mg O{sub 2}/mg coal hr for coal sample No.20 (Beulah pyrolyzed at 300 C) to 6.05 mg O{sub 2}/mg coal hr for coal sample No.8 (wyodak aged and pyrolyzed at 300 C). Aging of coal followed by pyrolysis was observed to contribute to higher reaction rates. Reaction enthalpies ranged from 0.42 to 1580 kcal/gm/mol O{sub 2}.

  14. Use of coal combustion by-products for solidification/stabilization of hazardous wastes

    SciTech Connect

    Hassett, D.J.; Pflughoeft-Hassett, D.F.

    1997-05-01

    Five low-rank coal combustion fly ash samples extensively characterized in previous projects were used as a pool of candidate materials for potential use as waste stabilization agents. Two of these fly ash samples were selected because ettringite formed in the solid in long-term leaching experiments, and an associated reduction in leachate concentration of at least one trace element was noted for each sample. The stabilization experiments were designed to evaluate the removal of relatively high concentrations of boron and selenium from a simulated wastewater. Sulfate was added as one variable in order to determine if high concentrations of sulfate would impact the ability of the ettringite to include trace elements in its structure. The following conclusions can be drawn from the information obtained in this research: CCBs (coal combustion by-products) can be useful in the chemical fixation of potentially hazardous trace elements; indication of ettringite formation alone is not adequate for selecting a CCB for waste stabilization applications; moderate sulfate concentrations do not promote or inhibit trace element sorption; ettringite formation mechanisms may impact trace element fixation and need to be elucidated; laboratory demonstration of the CCB with the stabilization process being proposed is necessary to verify the efficacy of the material and process; and the final waste form must be evaluated prior to management according to the required regulatory procedures.

  15. EFFECTS OF COMBUSTION PARAMETERS ON POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN HOMOLOGUE PROFILES FROM MUNICIPAL WASTE AND COAL CO-COMBUSTION

    EPA Science Inventory

    Variation in polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD and PCDF) homologue profiles from a pilot scale (0.6 MWt, 2x106 Btu/hr), co-fired-fuel [densified refuse derived fuel (dRDF) and high-sulfur Illinois coal] combustion system was used to provide i...

  16. Heavy duty gas turbine combustion tests with simulated low BTU coal gas

    SciTech Connect

    Ekstrom, T.E.; Battista, R.A.; Maxwell, G.P.

    1992-12-31

    There is an increasing industry interest in integrated gas turbine combined cycle plants in which coal gasifiers provide the fuel for the gas turbines. Some gasifier plant designs, including the air-blown processes, some integrated oxygen blown processes and some oxygen-blown processes followed by heavy moisturization, produce fuel gases which have lower heating values ranging from 130 to below 100 BTU/scf for which there is little gas turbine combustion experience. This program has the objectives to: Parametrically determine the effects of moisture, nitrogen and carbon dioxide as diluents so that the combustion characteristics of many varieties of gasification product gases can be reasonably predicted without physically testing each specific gas composition; determine emissions characteristics including NO{sub x}, CO, levels etc. associated with each of the diluents; operate with two syngas compositions; DOE chosen air-blown and integrated oxygen-blown, to confirm that the combustion characteristics are in line with predictions; determine if ``logical`` refinements to the fuel nozzle will yield improved performance for LBTU fuels; determine the conversion rate of ammonia to NO{sub x}; determine the effects of methane inclusion in the fuel.

  17. Heavy duty gas turbine combustion tests with simulated low BTU coal gas

    SciTech Connect

    Ekstrom, T.E.; Battista, R.A.; Maxwell, G.P.

    1992-01-01

    There is an increasing industry interest in integrated gas turbine combined cycle plants in which coal gasifiers provide the fuel for the gas turbines. Some gasifier plant designs, including the air-blown processes, some integrated oxygen blown processes and some oxygen-blown processes followed by heavy moisturization, produce fuel gases which have lower heating values ranging from 130 to below 100 BTU/scf for which there is little gas turbine combustion experience. This program has the objectives to: Parametrically determine the effects of moisture, nitrogen and carbon dioxide as diluents so that the combustion characteristics of many varieties of gasification product gases can be reasonably predicted without physically testing each specific gas composition; determine emissions characteristics including NO[sub x], CO, levels etc. associated with each of the diluents; operate with two syngas compositions; DOE chosen air-blown and integrated oxygen-blown, to confirm that the combustion characteristics are in line with predictions; determine if logical'' refinements to the fuel nozzle will yield improved performance for LBTU fuels; determine the conversion rate of ammonia to NO[sub x]; determine the effects of methane inclusion in the fuel.

  18. Influence of sulfur in coals on char morphology and combustion. Technical report, 1 September 1991--30 November 1991

    SciTech Connect

    Marsh, H.

    1991-12-31

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  19. PAH emissions from coal combustion and waste incineration.

    PubMed

    Hsu, Wei Ting; Liu, Mei Chen; Hung, Pao Chen; Chang, Shu Hao; Chang, Moo Been

    2016-11-15

    The characteristics of PAHs that are emitted by a municipal waste incinerator (MWI) and coal-fired power plant are examined via intensive sampling. Results of flue gas sampling reveal the potential for PAH formation within the selective catalytic reduction (SCR) system of a coal-fired power plant. In the large-scale MWI, the removal efficiency of PAHs achieved with the pilot-scaled catalytic filter (CF) exceeds that achieved by activated carbon injection with a bag filter (ACI+BF) owing to the effective destruction of gas-phase contaminants by a catalyst. A significantly lower PAH concentration (1640ng/g) was measured in fly ash from a CF module than from an ACI+BF system (5650ng/g). Replacing the ACI+BF system with CF technology would significantly reduce the discharge factor (including emission and fly ash) of PAHs from 251.6 to 77.8mg/ton-waste. The emission factors of PAHs that are obtained using ACI+BF and the CF system in the MWI are 8.05 and 7.13mg/ton, respectively. However, the emission factor of MWI is significantly higher than that of coal-fired power plant (1.56mg/ton). From the perspective of total environmental management to reduce PAH emissions, replacing the original ACI+BF process with a CF system is expected to reduce environmental impact thereof.

  20. PAH emissions from coal combustion and waste incineration.

    PubMed

    Hsu, Wei Ting; Liu, Mei Chen; Hung, Pao Chen; Chang, Shu Hao; Chang, Moo Been

    2016-11-15

    The characteristics of PAHs that are emitted by a municipal waste incinerator (MWI) and coal-fired power plant are examined via intensive sampling. Results of flue gas sampling reveal the potential for PAH formation within the selective catalytic reduction (SCR) system of a coal-fired power plant. In the large-scale MWI, the removal efficiency of PAHs achieved with the pilot-scaled catalytic filter (CF) exceeds that achieved by activated carbon injection with a bag filter (ACI+BF) owing to the effective destruction of gas-phase contaminants by a catalyst. A significantly lower PAH concentration (1640ng/g) was measured in fly ash from a CF module than from an ACI+BF system (5650ng/g). Replacing the ACI+BF system with CF technology would significantly reduce the discharge factor (including emission and fly ash) of PAHs from 251.6 to 77.8mg/ton-waste. The emission factors of PAHs that are obtained using ACI+BF and the CF system in the MWI are 8.05 and 7.13mg/ton, respectively. However, the emission factor of MWI is significantly higher than that of coal-fired power plant (1.56mg/ton). From the perspective of total environmental management to reduce PAH emissions, replacing the original ACI+BF process with a CF system is expected to reduce environmental impact thereof. PMID:27391862

  1. Mineral impurities in coal combustion - behaviour, problems and remedial measures

    SciTech Connect

    Raask, E.

    1985-01-01

    Chapters cover the following topics: influence of coal mineral matter on boiler design; mineral impurities in coal; quality of coal utilized in power stations; coal grinding, abrasive fuel minerals and plant wear; particulate silicate minerals in boiler flame; reactions of nonsilicate impurities in coal flames; creation, capture and coalescence of particulate ash in boiler flame; slag viscosity; sintering, fusion and slagging propensities of coal ashes; adhesion of ash deposit on boiler tubes and refractory materials; deposition mechanisms, rate measurements and the mode of formation of boiler deposits; thermal radiation and heat transfer properties of boiler deposits; measures to combat boiler fouling and slagging; some specific ash-related problems with U.S. coals; use of additives in coal-fired boilers; high temperature corrosion in coal-fired plants; ash impaction erosion wear; low temperature fouling and corrosion; and comparison of ash-related problems in pulverized fuel fired and other coal- fired systems.

  2. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Winschel, R.A.; Brandes, S.D.; Robbins, G.A.; Burke, F.P.

    1991-11-01

    Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-field: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  3. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Brandes, S.D.; Winschel, R.A.; Burke, F.P.; Robbins, G.A.

    1991-09-01

    Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  4. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Robbins, G.A.; Brandes, S.D.; Winschel, R.A.; Burke, F.P.

    1992-03-01

    CONSOL R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  5. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Robbins, G.A.; Brandes, S.D.; Winschel, R.A.; Burke, F.P.

    1991-11-01

    Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  6. Hydrogen production from the steam-iron process with direct reduction of iron oxide by chemical looping combustion of coal char

    SciTech Connect

    Jing-biao Yang; Ning-sheng Cai; Zhen-shan Li

    2008-07-15

    Experimental results performed with a fluidized-bed reactor supported the feasibility of the three processes including direct reduction of iron oxide by char, H{sub 2} production by the steam-iron process, and the oxidation of Fe{sub 3}O{sub 4} resulting from the steam-iron process to the original Fe{sub 2}O{sub 3} by air. Chars resulting from a Chinese lignite loaded with K{sub 2}CO{sub 3} were used successfully as a reducing material, leading to the reduction of Fe{sub 2}O{sub 3} to FeO and Fe for the steam-iron process, which was confirmed by both the off-gases concentrations and X-ray diffractometer analysis. The reduction of Fe{sub 2}O{sub 3} by K-10-char at 1073 K is desirable from the perspective of the carbon conversion rate and high concentration of CO{sub 2}. The carbon in char was completely converted to CO{sub 2} when the mass ratio of Fe{sub 2}O{sub 3}/K-10-char was increased to 10/0.3. The oxidation rate of K-10-char by Fe{sub 2}O{sub 3} without a gasifying agent was comparable to the K-10-char steam gasification rate. The fractions of FeO and Fe in the reduced residue were 43 and 57%, respectively, in the case of 3 g of Fe{sub 2}O{sub 3} and 0.5 g of K-10-char, which was verified by the total H{sub 2} yield equaling 1000 mL/g K-10-char from the steam-iron process. The time that it took to achieve complete oxidation of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} by air with an 8.7% O{sub 2} concentration at 1073 K was about 15 min. 53 refs., 19 figs., 5 tabs.

  7. Physical structure changes of Canadian coals during combustion

    SciTech Connect

    Gentzis, T.; Chambers, A.

    1995-01-01

    A subbituminous (Coal A), and both high-volatile (Coal B) and low-volatile bituminous (Coal C) coals were chosen to examine coals of different rank and reactivity. Coal A and Coal B were very reactive, with burnouts of 95% and 88% achieved under stable operating conditions. Coal C was relatively unreactive. It was not possible to achieve a stable flame with the burnout decreasing below 50% in less than 1 h. Direct comparison of the partially burnt samples from the three coals was difficult because of the different reactivities. Coals A and B burned so rapidly that it was not possible to collect samples below 70% burnout. Conversely, it was not possible to generate samples of Coal C char at burnouts above 72%. Coal A showed a continuous decrease in particle size with burnout. Coal B showed a significant size decrease only before 70% burnout, whereas coal C actually increased in size up to 60% burnout, followed by a slight decrease. Surface area analysis of Coal A indicated a large surface area contained in micropores. At high levels of burnout (above 90%), the surface area decreased. The same behavior was observed for coal B. While coal C also showed this large increase in surface area, the decrease occurred at about 50% burnout, much earlier than for the other coals. Results of mercury porosimetry tests on the partially burnt samples revealed a significant change in the pore volume for both Coals A and B, while no large changes were observed for Coal C. It was difficult to draw any conclusions from the porosimetry results due to the different particle size of the chars and wide variance in the measurements.

  8. Modeling of pulverized coal combustion processes in a vortex furnace of improved design. Part 1: Flow aerodynamics in a vortex furnace

    NASA Astrophysics Data System (ADS)

    Krasinsky, D. V.; Salomatov, V. V.; Anufriev, I. S.; Sharypov, O. V.; Shadrin, E. Yu.; Anikin, Yu. A.

    2015-02-01

    Some results of the complex experimental and numerical study of aerodynamics and transfer processes in a vortex furnace, whose design was improved via the distributed tangential injection of fuel-air flows through the upper and lower burners, were presented. The experimental study of the aerodynamic characteristics of a spatial turbulent flow was performed on the isothermal laboratory model (at a scale of 1 : 20) of an improved vortex furnace using a laser Doppler measurement system. The comparison of experimental data with the results of the numerical modeling of an isothermal flow for the same laboratory furnace model demonstrated their agreement to be acceptable for engineering practice.

  9. Advanced coal-fueled gas turbine systems: Subscale combustion testing. Topical report, Task 3.1

    SciTech Connect

    Not Available

    1993-05-01

    This is the final report on the Subscale Combustor Testing performed at Textron Defense Systems` (TDS) Haverhill Combustion Laboratories for the Advanced Coal-Fueled Gas Turbine System Program of the Westinghouse Electric Corp. This program was initiated by the Department of Energy in 1986 as an R&D effort to establish the technology base for the commercial application of direct coal-fired gas turbines. The combustion system under consideration incorporates a modular staged, rich-lean-quench, Toroidal Vortex Slogging Combustor (TVC) concept. Fuel-rich conditions in the first stage inhibit NO{sub x} formation from fuel-bound nitrogen; molten coal ash and sulfated sorbent are removed, tapped and quenched from the combustion gases by inertial separation in the second stage. Final oxidation of the fuel-rich gases, and dilution to achieve the desired turbine inlet conditions are accomplished in the third stage, which is maintained sufficiently lean so that here, too, NO{sub x} formation is inhibited. The primary objective of this work was to verify the feasibility of a direct coal-fueled combustion system for combustion turbine applications. This has been accomplished by the design, fabrication, testing and operation of a subscale development-type coal-fired combustor. Because this was a complete departure from present-day turbine combustors and fuels, it was considered necessary to make a thorough evaluation of this design, and its operation in subscale, before applying it in commercial combustion turbine power systems.

  10. Integrated coal cleaning, liquefaction, and gasification process

    DOEpatents

    Chervenak, Michael C.

    1980-01-01

    Coal is finely ground and cleaned so as to preferentially remove denser ash-containing particles along with some coal. The resulting cleaned coal portion having reduced ash content is then fed to a coal hydrogenation system for the production of desirable hydrocarbon gases and liquid products. The remaining ash-enriched coal portion is gasified to produce a synthesis gas, the ash is removed from the gasifier usually as slag, and the synthesis gas is shift converted with steam and purified to produce the high purity hydrogen needed in the coal hydrogenation system. This overall process increases the utilization of as-mined coal, reduces the problems associated with ash in the liquefaction-hydrogenation system, and permits a desirable simplification of a liquids-solids separation step otherwise required in the coal hydrogenation system.

  11. Application of Foam-gel Technique to Control CO Exposure Generated During Spontaneous Combustion of Coal in Coal Mines.

    PubMed

    Ren, Xing W; Wang, Feng Z; Guo, Qing; Zuo, Zhao B; Fang, Qi S

    2015-01-01

    In China, 47.3% of state-owned coal mines are located in coal seams that are prone to spontaneous combustion. The spontaneous combustion of coal is the main cause of the generation of a large amount of carbon monoxide, which can cause serious health issues to miners. A new technique using foam-gel formation was developed to effectively control the spontaneous combustion of coal. The gel can capture more than 90% of the water in the grout and at the same time the foam can cover dangerous areas in the goaf by stacking and cooling of foam in all directions. In this study, a mechanism of foam-gel formation was introduced and the optimal proportions of additives were defined based on experiments of different foaming properties, gelling time and water loss rate as the main index parameters. The results of a field application in a coal mine promise that this new technique would effectively prevent coal oxidation in the goaf and reduce the generation of carbon monoxide.

  12. Environmentally sound thermal energy extraction from coal and wastes using high temperature air combustion technology

    SciTech Connect

    Yoshikawa, Kunio

    1999-07-01

    High temperature air combustion is one of promising ways of burning relatively low BTU gas obtained from gasification of low grade coal or wastes. In this report, the author proposes a new power generation system coupled with high temperature air gasification of coal/wastes and high temperature air combustion of the syngas from coal/wastes. This system is realized by employing Multi-staged Enthalpy Extraction Technology (MEET). The basic idea of the MEET system is that coal or wastes are gasified with high temperature air of about 1,000 C, then the generated syngas is cooled in a heat recovery boiler to be cleaned-up in a gas cleanup system (desulfurization, desalinization and dust removal). Part of thermal energy contained in this cleaned-up syngas is used for high temperature air preheating, and the complete combustion of the fuel gas is done using also high temperature air for driving gas turbines or steam generation in a boiler.

  13. A numerical analysis of pulverized coal combustion in a multiburner furnace

    SciTech Connect

    Nozomu Hashimoto; Ryoichi Kurose; Hirofumi Tsuji; Hiromi Shirai

    2007-08-15

    A three-dimensional numerical simulation is applied to a pulverized coal combustion field in a furnace equipped with three burners, and the trajectories of the coal particles with respect to each burner, which are hardly obtained experimentally, are also investigated in detail. Simulation results are compared with experimental results. The results show that the numerical and experimental results are consistent generally. Also, the examination of the particle trajectories shows that most of the unburned carbon originates from the upper-stage burner. This result suggests that the overall unburned fraction can be reduced by supplying coal with a low combustibility to lower- or middle-stage burners and supplying coal with a high combustibility to the upper-stage burner. 50 refs., 14 figs., 4 tabs.

  14. The physical and chemical characteristics of pulverized coal combustion ashes

    SciTech Connect

    Ozasa, Kazuo; Kamijo, Tsunao; Owada, Tetsuo; Hosoda, Nobumichi

    1999-07-01

    Japan is the world's largest consumer of coal. Most of it is imported from various countries around the world. While coal generates more CO{sub 2}, which contributes to the greenhouse effect more than other types of fuel, plans are being drawn up to depend more on coal energy in order to maintain diversity in energy sources. Production of coal ash will increase as a result. In Japan, therefore, the public and private sectors are active in both developing and implementing clean, efficient and effective coal utilization technologies. More than 100 types of coal are being burned in Japan at present. For example, a power generating plant burns 20 to 40 different types of coal annually. Since a single type or coal blended with several different types are burned in Japan, the properties of coal ash differ by consuming plant and season. Therefore, understanding coal ash characteristics based on various properties is essential to the effective utilization of coal. The center of Coal Utilization, Japan has researched and developed effective utilization of coal ash as a supplementary project of the Ministry of International Trade and Industry. Chemical, physical, soil, and leaching characteristics, which are fundamental to using pulverized coal ash as a civil engineering material in large quantities, were selected and are described in this report.

  15. Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions

    EPA Science Inventory

    Abstract for presentation on Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions. The abstract is attached.

  16. Method of operating a two-stage coal gasifier

    DOEpatents

    Tanca, Michael C.

    1982-01-01

    A method of operating an entrained flow coal gasifier (10) via a two-stage gasification process. A portion of the coal (18) to be gasified is combusted in a combustion zone (30) with near stoichiometric air to generate combustion products. The combustion products are conveyed from the combustion zone into a reduction zone (32) wherein additional coal is injected into the combustion products to react with the combustion products to form a combustible gas. The additional coal is injected into the reduction zone as a mixture (60) consisting of coal and steam, preferably with a coal-to-steam weight ratio of approximately ten to one.

  17. Next Generation Pressurized Oxy-Coal Combustion: High Efficiency and No Flue Gas Recirculation

    SciTech Connect

    Rue, David

    2013-09-30

    found a number of modifications and adjustments that could provide higher efficiency and better use of available work. Conclusions from this analysis will help guide the analyses and CFD modeling in future process development. The MBB technology has the potential to be a disruptive technology that will enable coal combustion power plants to be built and operated in a cost effective way, cleanly with no carbon dioxide emissions. A large amount of work is needed to quantify and confirm the great promise of the MBB technology. A Phase 2 proposal was submitted to DOE and other sponsors to address the most critical MBB process technical gaps. The Phase 2 proposal was not accepted for current DOE support.

  18. Heat and mass transfer in fluidized-bed furnaces in combustion of a coal-water mixture

    NASA Astrophysics Data System (ADS)

    Berg, B. V.; Bogatova, T. F.

    1996-11-01

    The possibility in principle of burning highly ballasted fuel, including irrigated fuel, is considered. The permissible limits of the ash content and the moisture content are determined. The process of the thermal interaction between a drop of a coal-water mixture (CWM) and a fluidized bed is analyzed. Calculations of the distribution of volatiles and moisture in the fluidized bed in one-sided introduction of CWM are performed. The combustion of a CWM in a boiler furnace confirmed the practical possibility and expediency of recovering irrigated fuel waste of coal cleaning by this method.

  19. Proof of concept for integrating oxy-fuel combustion and the removal of all pollutants from a coal fired flame

    SciTech Connect

    Ochs, Thomas L.; Patrick, Brian; Oryshchyn, Danylo B.; Gross, Alex; Summers, Cathy A.; Simmons, William; Schoenfield, Mark; Turner, Paul C.

    2005-01-01

    The USDOE/Albany Research Center and Jupiter Oxygen Corporation, working together under a Cooperative Research and Development Agreement, have demonstrated proof-of-concept for the integration of Jupiter’s oxy-fuel combustion and an integrated system for the removal of all stack pollutants, including CO2, from a coal-fired flame. The components were developed using existing process technology with the addition of a new oxy-coal combustion nozzle. The results of the test showed that the system can capture SOx, NOx, particulates, and even mercury as a part of the process of producing liquefied CO2 for sequestration. This is part of an ongoing research project to explore alternative methods for CO2 capture that will be applicable to both retrofit and new plant construction.

  20. Understanding Combustion Processes Through Microgravity Research

    NASA Technical Reports Server (NTRS)

    Ronney, Paul D.

    1998-01-01

    A review of research on the effects of gravity on combustion processes is presented, with an emphasis on a discussion of the ways in which reduced-gravity experiments and modeling has led to new understanding. Comparison of time scales shows that the removal of buoyancy-induced convection leads to manifestations of other transport mechanisms, notably radiative heat transfer and diffusional processes such as Lewis number effects. Examples from premixed-gas combustion, non-premixed gas-jet flames, droplet combustion, flame spread over solid and liquid fuels, and other fields are presented. Promising directions for new research are outlined, the most important of which is suggested to be radiative reabsorption effects in weakly burning flames.

  1. Process for selective grinding of coal

    DOEpatents

    Venkatachari, Mukund K.; Benz, August D.; Huettenhain, Horst

    1991-01-01

    A process for preparing coal for use as a fuel. Forming a coal-water slurry having solid coal particles with a particle size not exceeding about 80 microns, transferring the coal-water slurry to a solid bowl centrifuge, and operating same to classify the ground coal-water slurry to provide a centrate containing solid particles with a particle size distribution of from about 5 microns to about 20 microns and a centrifuge cake of solids having a particle size distribution of from about 10 microns to about 80 microns. The classifer cake is reground and mixed with fresh feed to the solid bowl centrifuge for additional classification.

  2. Combustion of Coal-Mule Briquettes / Spalanie Brykietów Z Mułu Węglowego

    NASA Astrophysics Data System (ADS)

    Kijo-Kleczkowska, Agnieszka

    2013-09-01

    Combustion technologies coal-mule fuels create a number of new possibilities for organising combustion processes so that they fulfil contemporary requirements (e.g., in terms of the environment protection- related issues). The paper describes the problems of coal-mule fuel combustion that have acquired a wider significance as the quality requirements of coal combustion in power plants have been growing. Coal mines that want to fulfill expectations of power industry workers have been forced to develop and modernize plants of coal wet cleaning. It all results in the growing amount of waste arising in the process of coal wet cleaning which contains smaller and smaller coal undersizes. In this situation the concept of direct combustion of the above mentioned waste and their co-combustion with other fuels, coal and biomass, seems to be attractive. Biomass is one from the most promising sources of renewable energy. The main aim of the paper is to identify the mechanism and kinetics of combustion of coal-mule fuels and their co- -combustion with coal and biomass in the briquettes form based on extensive experimental research in air. Niekorzystny bilans paliwowy naszego kraju powoduje nadmierne obciążenie środowiska, wywołane emisją CO2, NOx, SO2 i pyłów, a także powiększeniem powierzchni koniecznych na składowanie wciąż narastających stałych odpadów paleniskowych. Górnictwo, od którego energetyka oczekuje coraz lepszego paliwa, musi stosować głębsze wzbogacanie węgla. Powoduje to ciągłą produkcję odpadów w postaci mułów poflotacyjnych. Najlepszą metodą utylizacji tych mułów jest ich spalanie w postaci zawiesin, a także ich współspalanie z innymi paliwami, węglem czy biomasą. Biomasa jest bowiem jednym z najbardziej obiecujących źródeł OZE, a jej współspalanie z paliwami węglowymi znajduje w ostatnich latach coraz szersze zastosowanie zarówno w kraju, jak i na świecie. W tej sytuacji istotne jest prowadzenie badań naukowych

  3. A study of on-line analysis of chlorine discharge during coal combustion

    SciTech Connect

    Heidbrink, J.; Keene, J.; Li, H.

    1996-10-01

    Three peak maxima representing HCl evolution during coal combustion were identified using a TG-MS technique. The maximum temperature of the first peak of HCl evolution occurs around 300{degrees}C for all coals studied. This low temperature evolution is an indication that the first HCl evolution peak is due to thermal effects and is not related to the rank of coal. The first HCl peak is, we believe, HCl that is normally adsorbed on pore walls. We also observe a correlation between the maximum temperature of the second HCl peak from the MS data and the maximum temperature of the associated DTG curve combustion profile (which is coal rank dependent). The second HCl peak is due to the oxidation of coal and subsequent HCl release. The third peak maximum occurs at 650-850{degrees}C and is due to the decomposition of inorganic chloride.

  4. Short-term influence of coal mine reclamation using coal combustion residues on groundwater quality.

    PubMed

    Cheng, Chin-Min; Amaya, Maria; Butalia, Tarunjit; Baker, Robert; Walker, Harold W; Massey-Norton, John; Wolfe, William

    2016-11-15

    Two full-scale coal mine reclamation projects using coal combustion residues (CCRs) were recently carried out at highwall pit complexes near the Conesville and Cardinal coal-fired power plants owned by American Electric Power. The environment impacts of the reclamation projects were examined by regularly monitoring the leaching characteristics of the backfilling CCRs and the water quality of the uppermost aquifers underlying the sites. With over five years of field monitoring, it shows that the water quality at both demonstration sites had changed since the reclamation began. By analyzing the change of the hydrogeochemical properties, it was concluded that the water quality impact observed at the Conesville Five Points site was unlikely due to the seepage of FGD material leachates. Reclamation activities, such as logging, grading, and dewatering changed the hydrogeological conditions and resulted in the observed water quality changes. The same hydrogeological effect on water quality was also found at the Cardinal Star Ridge site during the early stage of the reclamation (approximately the first 22months). Subsequent measurements showed the water quality to be strongly influenced by the water in the reclaimed highwall pit. Despite the changes to the water quality, the impacts are insignificant and temporary. None of the constitutes showed concentration levels higher than the regulatory leaching limits set by the Ohio Department of Natural Resources' Division of Mineral Resources Management for utilizing CCRs in mined land reclamation. Compared to the local aquifers, the concentrations of eleven selected constituents remained at comparable levels throughout the study period. There are four constituents (i.e., As, Be, Sb, and Tl) that exceeded their respective MCLs after the reclamation began. These detections were found shortly (i.e., within 2years) after the reclamation began and decreased to the levels either lower than the respective detection limits or similar to

  5. Short-term influence of coal mine reclamation using coal combustion residues on groundwater quality.

    PubMed

    Cheng, Chin-Min; Amaya, Maria; Butalia, Tarunjit; Baker, Robert; Walker, Harold W; Massey-Norton, John; Wolfe, William

    2016-11-15

    Two full-scale coal mine reclamation projects using coal combustion residues (CCRs) were recently carried out at highwall pit complexes near the Conesville and Cardinal coal-fired power plants owned by American Electric Power. The environment impacts of the reclamation projects were examined by regularly monitoring the leaching characteristics of the backfilling CCRs and the water quality of the uppermost aquifers underlying the sites. With over five years of field monitoring, it shows that the water quality at both demonstration sites had changed since the reclamation began. By analyzing the change of the hydrogeochemical properties, it was concluded that the water quality impact observed at the Conesville Five Points site was unlikely due to the seepage of FGD material leachates. Reclamation activities, such as logging, grading, and dewatering changed the hydrogeological conditions and resulted in the observed water quality changes. The same hydrogeological effect on water quality was also found at the Cardinal Star Ridge site during the early stage of the reclamation (approximately the first 22months). Subsequent measurements showed the water quality to be strongly influenced by the water in the reclaimed highwall pit. Despite the changes to the water quality, the impacts are insignificant and temporary. None of the constitutes showed concentration levels higher than the regulatory leaching limits set by the Ohio Department of Natural Resources' Division of Mineral Resources Management for utilizing CCRs in mined land reclamation. Compared to the local aquifers, the concentrations of eleven selected constituents remained at comparable levels throughout the study period. There are four constituents (i.e., As, Be, Sb, and Tl) that exceeded their respective MCLs after the reclamation began. These detections were found shortly (i.e., within 2years) after the reclamation began and decreased to the levels either lower than the respective detection limits or similar to

  6. Coal liquefaction process employing multiple recycle streams

    SciTech Connect

    Carr, N.; Schleppy, R.; Shah, Y.

    1980-07-08

    A combination coal liquefaction-gasification process comprises passing hydrogen and a liquefaction zone feed slurry comprising mineral-containing feed coal, recycle dissolved liquid coal solvent, recycle dissolved coal which is solid at room temperature and recycle mineral residue to a coal liquefaction zone to dissolve hydrocarbonaceous material from mineral residue and to hydrocrack said hydrocarbonaceous material to produce a liquefaction zone effluent mixture comprising hydrocarbon gases, dissolved liquid coal, solid dissolved coal and suspended mineral residue; recycling to said liquefaction zone feed slurry a portion of said dissolved liquid coal,solid dissolved coal and mineral residue; recycling to said liquefaction zone an other portion of ssaid solid dissolved coal and mineral residue independently of said liquefaction zone feed slurry; said liquefaction zone producing a greater net yield on a weight basis after recycle of 450 to 850/sup 0/F dissolved liquid coal as compared to the net yield on a weight basis after recycle of 850/sup 0/F solid dissolved coal; separating dissolved liquid coal and hydrocarbon gases from non-recycled solid dissolved coal and mineral residue to produce a gasifier feed slurry comprising substantially the entire net yield of solid dissolved coal and mineral residue of said liquefaction zone; passing said gasifier feed slurry to a gasification zone includin G an oxidation zone for the conversion of the hydrocarbonaceous material therein to synthesis gas; converting at least a portion of said synthesis gas to a gaseous hydrogen-rich stream and passing said hydrogen-rich stream to said liquefaction zone to supply process hydrogen thereto; the amount of hydrocarbonaceous material passed to said gasification zone being sufficient to enable said gasification zone at least the entire hydrogen requirement of said liquefaction zone.

  7. Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

    SciTech Connect

    Adnadjevic, B.; Popovic, A.; Mikasinovic, B.

    2009-07-01

    The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel, zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.

  8. Process for reducing sulfur in coal char

    DOEpatents

    Gasior, Stanley J.; Forney, Albert J.; Haynes, William P.; Kenny, Richard F.

    1976-07-20

    Coal is gasified in the presence of a small but effective amount of alkaline earth oxide, hydroxide or carbonate to yield a char fraction depleted in sulfur. Gases produced during the reaction are enriched in sulfur compounds and the alkaline earth compound remains in the char fraction as an alkaline earth oxide. The char is suitable for fuel use, as in a power plant, and during combustion of the char the alkaline earth oxide reacts with at least a portion of the sulfur oxides produced from the residual sulfur contained in the char to further lower the sulfur content of the combustion gases.

  9. Mercury Emission from Co-Combustion of Sludge and Coal in a CFB Incinerator

    NASA Astrophysics Data System (ADS)

    Duan, Y. F.; Zhao, C. S.; Wu, C. J.; Wang, Y. J.

    An experimental study on co-combustion of sludge and coal were conducted in a circulating fluidized bed incinerator with the dense bed cross section area of 0.23m×0.23m and the height of 7m. The mercury mass balance was measured and the distribution of mercury speciation in flue gas was discussed. Effects of major operational parameters such as Ca/S molar ratio, desulfurization sorbents, excess air coefficient, co-combustion temperature, and SO2 and NOx concentrations on the distribution of mercury speciation in flue gas, mercury in fly ash and slag were investigated during the co-combustion process. The results show that majority of mercury goesinto the fluegas in which the elemental mercury is the major speciation. Ca-based sorbent can remove Hg2+ in flue gas effectively, in which CaO has better mercury removal effect than CaCO3. The content of Hg2+ in flue gas increases with increasing of the concentration of SO2 and NOx in flue gas. It can also be concluded that the excessair coefficient exerts dominant influences on mercury speciation among the flue gas, fly ash and bottom ash.

  10. FUNDAMENTAL INVESTIGATION OF FUEL TRANSFORMATIONS IN PULVERIZED COAL COMBUSTION AND GASIFICATION TECHNOLOGIES

    SciTech Connect

    Robert Hurt; Joseph Calo; Thomas H. Fletcher; Alan Sayre

    2005-04-29

    The goal of this project was to carry out the necessary experiments and analyses to extend current capabilities for modeling fuel transformations to the new conditions anticipated in next-generation coal-based, fuel-flexible combustion and gasification processes. This multi-organization, multi-investigator project has produced data, correlations, and submodels that extend present capabilities in pressure, temperature, and fuel type. The combined experimental and theoretical/computational results are documented in detail in Chapters 1-8 of this report, with Chapter 9 serving as a brief summary of the main conclusions. Chapters 1-3 deal with the effect of elevated pressure on devolatilization, char formation, and char properties. Chapters 4 and 5 deal with advanced combustion kinetic models needed to cover the extended ranges of pressure and temperature expected in next-generation furnaces. Chapter 6 deals with the extension of kinetic data to a variety of alternative solid fuels. Chapter 7 focuses on the kinetics of gasification (rather than combustion) at elevated pressure. Finally, Chapter 8 describes the integration, testing, and use of new fuel transformation submodels into a comprehensive CFD framework. Overall, the effects of elevated pressure, temperature, heating rate, and alternative fuel use are all complex and much more work could be further undertaken in this area. Nevertheless, the current project with its new data, correlations, and computer models provides a much improved basis for model-based design of next generation systems operating under these new conditions.

  11. A comparison study of ash formation during pilot-scale combustion of pulverized coal and coal-water slurry fuels

    SciTech Connect

    Miller, S.F.

    1992-01-01

    The objective of this study was to investigate the effect of fuel form. specifically pulverized coal and coal-water slurry fuel (CWSF), on the particle size distribution (PSD) and inorganic composition of the ash formed during combustion. Three areas of primary interest were fuel particle and droplet size distribution, mineral matter PSD, and the composition and occurrence of inorganics in the fuel. The reactions of pyrite, silicates, aluminosilicates, and alkali and alkaline earth elements during combustion are traced. Two coals, a West Virginia Elk Creek high volatile A bituminous coal and the North Dakota Beulah lignite, were fired as a standard utility grind pulverized fuel and a CWSF at 316.2 MJ/h at 20% excess air in the Penn State Combustion Laboratory down-fired combustor. Fuel PSD and droplet size distribution of the pulverized coal and CWSF are important in determining the PSD of the respective ash when the PSD of the mineral matter and the composition and occurrence of the inorganics in the two fuels are similar, as in the case of the Elk Creek fuels. The mechanism for ash formation in both Elk Creek fuels was coalescence and agglomeration of the inorganics in the coal. The Elk Creek CWSF ash was coarser than the pulverized coal ash due to the larger CWSF char size formed during atomization. The average diameter of the inorganic particles identified in the pulverized coal ash was 2.6 times smaller than those identified in the fuel. The mechanism for ash formation in the Beulah CWSF was coalescence and agglomeration of inherent mineral matter. The average diameter of the inorganic particles identified in the CWSF ash was 3.3 times larger than those identified in the fuel.

  12. The combustion kinetics of coal chars in oxygen-enriched environments.

    SciTech Connect

    Shaddix, Christopher R.; Murphy, Jeffrey J.

    2004-09-01

    Oxygen-enhanced and oxygen-fired pulverized coal combustion is actively being investigated to achieve emission reductions and reductions in flue gas cleanup costs, as well as for coal-bed methane and enhanced oil recovery applications. To fully understand the results of pilot scale tests and to accurately predict scale-up performance through CFD modeling, accurate rate expressions are needed to describe coal char combustion under these unconventional combustion conditions. In the work reported here, the combustion rates of two pulverized coal chars have been measured in both conventional and oxygen-enriched atmospheres. A combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometry diagnostic and a rapid-quench sampling probe has been used for this investigation. Highvale subbituminous coal and a high-volatile eastern United States bituminous coal have been investigated, over oxygen concentrations ranging from 6 to 36 mol% and gas temperatures of 1320-1800 K. The results from these experiments demonstrate that pulverized coal char particles burn under increasing kinetic control in elevated oxygen environments, despite their higher burning rates in these environments. Empirical fits to the data have been successfully performed over the entire range of oxygen concentrations using a single-film oxidation model. Both a simple nth-order Arrhenius expression and an nth-order Langmuir-Hinshelwood kinetic equation provide good fits to the data. Local fits of the nth-order Arrhenius expression to the oxygen-enriched and oxygen-depleted data produce lower residuals in comparison to fits of the entire dataset. These fits demonstrate that the apparent reaction order varies from 0.1 under near-diffusion-limit oxygen-depleted conditions to 0.5 under oxygen-enriched conditions. Burnout predictions show good agreement with measurements. Predicted char particle temperatures tend to be low for combustion in oxygen-depleted environments.

  13. Study of the combustion of low rank coal in a fluidized bed

    SciTech Connect

    Glaser, R.; Grimes, R.W.

    1991-09-01

    This report describes the results of preliminary combustion tests performed with Eagle Butte Coal in a bubbling, fluidized-bed combustion system. The system was designed for the combustion of low-rank coals and industrial wastes. The work, as proposed, was aimed at not only the evaluation of co-firing of waste material with coal, but also at developing modifications to first generation bubbling bed designs to improve the combustion performance during co-firing. However, the funding for the work was redirected and the combustion tests were suspended soon after the shakedown testing was completed. Consequently, this report describes the results of the tests completed prior to the redirection of the effort and funding. A total of 33 combustion tests were performed in a 6-inch diameter fluidized-bed combustor. Oxygen concentrations were measured at two points in the system; the vent line and at the interface between the fluid bed and the freeboard. These measurements provided a measure of the amount of conversion of coal within the fluidized bed compared to the conversion in the freeboard region. Typically, 75 to 80% of the conversion occurred within the bed. Several experiments were performed in which special bed internals were placed in the bed. The internals were designed to reduce bubble size in the bed thus increasing the surface area of the bubbles and hence promoting oxygen diffusion into the emulsion phase.

  14. Availability of trace elements in solid waste from fluidized bed combustion of coal

    SciTech Connect

    Rope, S.K.; Jornitz, R.S.; Suhre, D.T.

    1987-12-01

    This report presents data on the inorganic constituents (major and trace elements) of coal and solid waste from a coal-fired facility on the Idaho National Engineering Laboratory (INEL) which uses the fluidized bed combustion process. Three factors were used to assess the potential environmental impacts of elements in coal waste: (1) the concentrations relative to those measured previously in surrounding soils of the INEL (the enrichment ratio); (2) the availability of elements from waste relative to soils; and (3) toxicity or essentiality to biota. Considering both enrichment and availability, Al, B, Be, Ca, Cr, Na, Mo, Se, Sr, and Ti are most likely to be affected in the local environment due to fly ash deposition and/or resuspension of FBC waste. Only B, Cr, Mo, and Se are likely to be of concern in terms of toxicity. The high concentrations of Cr and B in FBC waste are expected to be toxic to plants. Concentrations of Se and Mo present in FBC waste have been shown to produce levels in plants which can be toxic to herbivorous animals. 14 refs, 1 fig., 4 tabs.

  15. Highly crystalline Zeolite-A from flyash of bituminous and lignite coal combustion.

    PubMed

    Rayalu, S S; Udhoji, J S; Munshi, K N; Hasan, M Z

    2001-11-16

    Flyash is being generated in voluminous amounts by large scale coal combustion process. It poses a serious threat to thermal power industries specifically, in India, wherein the percent of utilisation of flyash is very poor (3-5%). In view of this problem, newer methods of its disposal and utilisation are being explored. The synthesis of zeolite from flyash appears to be one of the most promising alternatives as it has emphasis on value addition to waste material. Flyashes originating from different sources of coal differ in their characteristics and have implications in this work on Zeolite-A production. These factors have been thoroughly investigated and the conditions favourable for formation of Zeolite-A have been delineated. The reactivity of flyash towards zeolite formation is directly dependent on the SiO(2)/Al(2)O(3) ratio, Fe(2)O(3) and CaO content. Amongst the flyashes investigated, so far the sub-bituminous coal based flyash with SiO(2)/Al(2)O(3) ratio of 3.47 appears to be a suitable substrate for Zeolite-A synthesis. These zeolites have been characterised with respect to XRD crystallinity, calcium binding capacity (CBC) and sorption capacity, wherein the crystallinity ranges from 50 to 100%, the CBC ranges from 290 to 560meq/100g and sorption capacity ranges from 16.6 to 23.8%.

  16. Analysis of rocket engine injection combustion processes

    NASA Technical Reports Server (NTRS)

    Salmon, J. W.

    1976-01-01

    A critique is given of the JANNAF sub-critical propellant injection/combustion process analysis computer models and application of the models to correlation of well documented hot fire engine data bases. These programs are the distributed energy release (DER) model for conventional liquid propellants injectors and the coaxial injection combustion model (CICM) for gaseous annulus/liquid core coaxial injectors. The critique identifies model inconsistencies while the computer analyses provide quantitative data on predictive accuracy. The program is comprised of three tasks: (1) computer program review and operations; (2) analysis and data correlations; and (3) documentation.

  17. An important missing source of atmospheric carbonyl sulfide: Domestic coal combustion

    NASA Astrophysics Data System (ADS)

    Du, Qianqian; Zhang, Chenglong; Mu, Yujing; Cheng, Ye; Zhang, Yuanyuan; Liu, Chengtang; Song, Min; Tian, Di; Liu, Pengfei; Liu, Junfeng; Xue, Chaoyang; Ye, Can

    2016-08-01

    Carbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) emissions generated from prevailing domestic coal stoves fueled with raw bituminous coal were studied under alternation cycles of flaming and smoldering combustion. The measurements in the laboratory and the farmer's house indicated that COS and CO emissions mainly occurred under the condition of flame extinguishment after coal loading, whereas SO2 emissions were mainly generated through combustion with flame. The COS emission factors for the domestic stoves in the laboratory and the farmer's house were recorded as 0.57 ± 0.10 g COS kg-1 and 1.43 ± 0.32 g COS kg-1, being approximately a factor of 50 and 125 greater than that generated from coal power plants, respectively. Based on the COS emission factors measured in this study, COS emission from only domestic coal combustion in China would be at least 30.5 ± 5.6 Gg S yr-1 which was 1 magnitude greater than the current COS estimation from the total coal combustion in China.

  18. METAL CAPTURE BY SORBENTS IN COMBUSTION PROCESSES

    EPA Science Inventory

    The article gives results of an investigation of the use of sorbents to control trace metal emissions from combustion processes and an exploration of the underlying mechanisms. mphasis was on mechanisms in which the metal vapor was reactively scavenged by simple commercial sorben...

  19. The chemical composition of tertiary Indian coal ash and its combustion behaviour - a statistical approach: Part 2

    NASA Astrophysics Data System (ADS)

    Sharma, Arpita; Saikia, Ananya; Khare, Puja; Dutta, D. K.; Baruah, B. P.

    2014-08-01

    In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study their genesis. The datasets from Part 1 used in this investigation (Part 2) show the contribution of major oxides towards ash fusion temperatures (AFTs). The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT is influenced by the increase of Fe2O3, Al2O3, SiO2, and CaO, respectively. Detrital-authigenic index (DAI) calculated from the ash composition and its relation with AFT indicates Sialoferric nature of these coals. The correlation analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were used to study the possible fouling, slagging, and abrasion potentials in boilers during the coal combustion processes. A positive relationship between slagging and heating values of the coal has been found in this study.

  20. Development and testing of commercial-scale, coal-fired combustion systems: Phase III. Final report

    SciTech Connect

    1996-03-01

    Based on studies that indicated a large potential for significantly increased coal-firing in the commercial sector, the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) sponsored a multi-phase development effort for advanced coal combustion systems. This Final Report presents the results of the last phase (Phase III) of a project for the development of an advanced coal-fired system for the commercial sector of the economy. The project performance goals for the system included dual-fuel capability (i.e., coal as primary fuel and natural gas as secondary fuel), combustion efficiency exceeding 99 percent, thermal efficiency greater than 80 percent, turndown of at least 3:1, dust-free and semi-automatic dry ash removal, fully automatic start-up with system purge and ignition verification, emissions performance exceeding New Source Performance Standards (NSPS) and approaching those produced by oil-fired, Commercial-sized units, and reliability, safety, operability, maintainability, and service life comparable to oil-fired units. The program also involved a site demonstration at a large facility owned by Striegel Supply Company, a portion of which was leased to MTCI. The site, mostly warehouse space, was completely unheated and the advanced coal-fired combustion system was designed and sized to heat this space. Three different coals were used in the project, one low and one high sulfur pulverized Pittsburgh No. 8 coal, and a micronized low volatile, bituminous coal. The sorbents used were Pfizer dolomitic limestone and an Anvil lime. More than 100 hours of screening test`s were performed to characterize the system. The parameters examined included coal firing rate, excess air level, ash recycle rate, coal type, dolomitic limestone feed rate, and steam injection rate. These tests indicated that some additional modifications for coal burning in the system were required.

  1. Co-combustion of peanut hull and coal blends: Artificial neural networks modeling, particle swarm optimization and Monte Carlo simulation.

    PubMed

    Buyukada, Musa

    2016-09-01

    Co-combustion of coal and peanut hull (PH) were investigated using artificial neural networks (ANN), particle swarm optimization, and Monte Carlo simulation as a function of blend ratio, heating rate, and temperature. The best prediction was reached by ANN61 multi-layer perception model with a R(2) of 0.99994. Blend ratio of 90 to 10 (PH to coal, wt%), temperature of 305°C, and heating rate of 49°Cmin(-1) were determined as the optimum input values and yield of 87.4% was obtained under PSO optimized conditions. The validation experiments resulted in yields of 87.5%±0.2 after three replications. Monte Carlo simulations were used for the probabilistic assessments of stochastic variability and uncertainty associated with explanatory variables of co-combustion process. PMID:27243606

  2. Co-combustion of peanut hull and coal blends: Artificial neural networks modeling, particle swarm optimization and Monte Carlo simulation.

    PubMed

    Buyukada, Musa

    2016-09-01

    Co-combustion of coal and peanut hull (PH) were investigated using artificial neural networks (ANN), particle swarm optimization, and Monte Carlo simulation as a function of blend ratio, heating rate, and temperature. The best prediction was reached by ANN61 multi-layer perception model with a R(2) of 0.99994. Blend ratio of 90 to 10 (PH to coal, wt%), temperature of 305°C, and heating rate of 49°Cmin(-1) were determined as the optimum input values and yield of 87.4% was obtained under PSO optimized conditions. The validation experiments resulted in yields of 87.5%±0.2 after three replications. Monte Carlo simulations were used for the probabilistic assessments of stochastic variability and uncertainty associated with explanatory variables of co-combustion process.

  3. Modeling the behavior of selenium in Pulverized-Coal Combustion systems

    SciTech Connect

    Senior, Constance; Otten, Brydger Van; Wendt, Jost O.L.; Sarofim, Adel

    2010-11-15

    The behavior of Se during coal combustion is different from other trace metals because of the high degree of vaporization and high vapor pressures of the oxide (SeO{sub 2}) in coal flue gas. In a coal-fired boiler, these gaseous oxides are absorbed on the fly ash surface in the convective section by a chemical reaction. The composition of the fly ash (and of the parent coal) as well as the time-temperature history in the boiler therefore influences the formation of selenium compounds on the surface of the fly ash. A model was created for interactions between selenium and fly ash post-combustion. The reaction mechanism assumed that iron reacts with selenium at temperatures above 1200 C and that calcium reacts with selenium at temperatures less than 800 C. The model also included competing reactions of SO{sub 2} with calcium and iron in the ash. Predicted selenium distributions in fly ash (concentration versus particle size) were compared against measurements from pilot-scale experiments for combustion of six coals, four bituminous and two low-rank coals. The model predicted the selenium distribution in the fly ash from the pilot-scale experiments reasonably well for six coals of different compositions. (author)

  4. Analysis of options for coal combustion waste management in the Pacific Basin

    SciTech Connect

    Elcock, D.; Gasper, J.

    1993-10-01

    Many Pacific Basin countries rely on oil for electricity production. Alternative fuel sources such as coal, which is available in the Pacific Basin, can help mitigate adverse impacts of sudden price increases or supply disruptions. Coal combustion produces solid and potentially hazardous wastes of concern to environmental regulators and utility managers. This paper identifies issues associated with managing coal combustion wastes in the Pacific Basin, using the state of Hawaii as a case study. Hawaii is typical of many Pacific Basin locations in that it depends on oil, has limited sites, for waste management operations, and is subject to domestic and international waste management regulations. The paper discusses coal-fired utility wastes, environmental impacts of coal combustion waste disposal, and regulatory requirements that impact coal waste management. From this baseline, potential on- and off-island options for coal waste management are identified. Waste management costs are estimated and non-quantifiable issues are addressed for each option. Many options are applicable across the Pacific Rim and may serve as a basis for future fuel-use decisions.

  5. Investigation of the behavior of potentially hazardous trace elements in Kentucky coals and combustion byproducts

    SciTech Connect

    Robertson, J.D.; Blanchard, L.J.; Srikantapura, S.; Parekh, B.K.; Lafferty, C.J.

    1996-12-31

    The minor- and trace-element content of coal is of great interest because of the potentially hazardous impact on human health and the environment resulting from their release during coal combustion. Of the one billion tons of coal mined annually in the United States, 85-90% is consumed by coal-fired power plants. Potentially toxic elements present at concentrations as low as a few egg can be released in large quantities from combustion of this magnitude. Of special concern are those trace elements that occur naturally in coal which have been designated as potential hazardous air pollutants (HAPs) in the 1990 Amendments to the Clean Air Act. The principle objective of this work was to investigate a combination of physical and chemical coal cleaning techniques to remove 90 percent of HAP trace elements at 90 percent combustibles recovery from Kentucky No. 9 coal. Samples of this coal were first subjected to physical separation by flotation in a Denver cell. The float fraction from the Denver cell was then used as feed material for hydrothermal leaching tests in which the efficacy of dilute alkali (NaOH) and acid (HNO{sub 3}) solutions at various temperatures and pressures was investigated. The combined column flotation and mild chemical cleaning strategy removed 60-80% of trace elements with greater than 85, recovery of combustibles from very finely ground (-325 mesh) coal. The elemental composition of the samples generated at each stage was determined using particle induced X-ray emission (PIXE) analysis. PIXE is a rapid, instrumental technique that, in principle, is capable of analyzing all elements from sodium through uranium with sensitivities as low as 1 {mu}g/g.

  6. Process for electrochemically gasifying coal using electromagnetism

    DOEpatents

    Botts, Thomas E.; Powell, James R.

    1987-01-01

    A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

  7. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-12-31

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  8. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-01-01

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  9. Fired heater for coal liquefaction process

    DOEpatents

    Ying, David H. S.; McDermott, Wayne T.; Givens, Edwin N.

    1985-01-01

    A fired heater for a coal liquefaction process is operated under conditions to maximize the slurry slug frequency and thereby improve the heat transfer efficiency. The operating conditions controlled are (1) the pipe diameter and pipe arrangement, (2) the minimum coal/solvent slurry velocity, (3) the maximum gas superficial velocity, and (4) the range of the volumetric flow velocity ratio of gas to coal/solvent slurry.

  10. Process for treating moisture laden coal fines

    DOEpatents

    Davis, Burl E.; Henry, Raymond M.; Trivett, Gordon S.; Albaugh, Edgar W.

    1993-01-01

    A process is provided for making a free flowing granular product from moisture laden caked coal fines, such as wet cake, by mixing a water immiscible substance, such as oil, with the caked coal, preferably under low shear forces for a period of time sufficient to produce a plurality of free flowing granules. Each granule is preferably comprised of a dry appearing admixture of one or more coal particle, 2-50% by weight water and the water immiscible substance.

  11. MUTATION SPECTRA OF SMOKY COAL COMBUSTION EMMISSIONS IN SALMONELLA REFLECTS THE TP53 AND KRAS MUTATIONS IN LUNG TUMORS FROM SMOKY COAL EXPOSED INDIVIDUALS

    EPA Science Inventory


    Mutation Spectra of Smoky Coal Combustion Emissions in Salmonella Reflect the TP53
    and KRAS Mutations in Lung Tumors from Smoky Coal-Exposed Individuals

    Abstract
    Nonsmoking women in Xuan Wei County, Yunnan Province, China who use smoky coal for cooking and h...

  12. Combustion behaviour of coal-waste flames in pulverized fuel firing systems

    SciTech Connect

    Gerhardt, T.; Cenni, R.; Spliethoff, H.; Hein, K.R.G.

    1997-07-01

    In the European countries, and especially in Germany, the disposal of waste material is becoming more and more a problem. Incineration plants which should provide the capacity to take over the thermal treatment of the waste material are hardly accepted by the population. For this reason it is nearly impossible to install new facilities. Moreover the prospect of future waste disposal will be dominated by the idea of separating waste streams and treating them specifically in order to reach the best possibilities for all kinds of further utilization. In municipal waste as well as in industrial residues there are many kinds of materials which occur separately. Their specific properties are often very homogenous and reliably Stable over a long time. For those materials where recycling is not possible or, due to economic aspects, not reasonable we have to think about energy recovery with the best way of thermal treatment. Power plants for the combustion of fossil fuels like coal can provide a high efficiency in energy conversion. If the range of hazardous matter in the waste streams is suitable to be treated and recovered by the existing flue gas cleaning system, co-combustion of waste in existing power plants can have both economical and environmental benefits in comparison to the normal waste incineration. Wastes of a sufficient amount and a homogeneous composition can be considered for co-combustion. By choosing the best combination of fuels and waste as fuel substitutes the aim is to use synergetic effects to improve the combustion process beyond the limits of a single fuel.

  13. Leaching of coal combustion products: Field and laboratory studies

    NASA Astrophysics Data System (ADS)

    Cheng, Chin-Min

    This study combines field monitoring and laboratory experiments to investigate the environmental impacts associated with the re-use of coal combustion by-products (CCPs). The monitoring data obtained from two full-scale CCP applications (i.e., re-use of fixated flue gas desulfurization (FGD) material as a low permeability liner for a swine manure pond and portland cement concrete pavements containing CCPs) allowed environmental impacts to be evaluated under real or simulated in-service conditions. A complimentary laboratory leaching study elucidated fundamental physical and chemical mechanisms that determine the leaching kinetics of inorganic contaminants from CCPs. In the first field study, water quality impacts associated with the re-use of FGD material as a low permeability liner for a swine manure pond were examined by monitoring the water quality of water samples collected from the pond surface water and a sump collection system beneath the liner over a period of 5 years. Water samples collected from the sump and pond surface water met all Ohio non-toxic criteria, and in fact, generally met all national primary and secondary drinking water standards. Furthermore it was found that hazardous (i.e., As, B, Cr, Cu, and Zn) and agricultural pollutants (i.e., phosphate and ammonia) were effectively retained by the FGD liner system. The retention might be due to both sorption and precipitation. In the second field study, the release of metals and metalloids from full-scale portland cement concrete pavements containing CCPs was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections under controlled loading and environmental conditions. Three types of portland-cement-concrete driving surfaces were tested, including a control section (i.e., ordinary portland cement (OPC) concrete) containing no fly ash and two sections in which fly ash was substituted for a fraction of the cement; i.e., 30% fly ash (FA30) and 50% fly ash (FA50

  14. [Inventories of atmospheric arsenic emissions from coal combustion in China, 2005].

    PubMed

    Tian, He-Zhong; Qu, Yi-Ping

    2009-04-15

    Anthropogenic arsenic (As) emitted from coal combustion is one of key trace elements leading to negative air pollution and national economy loss. It is of great significance to estimate the atmospheric arsenic emission for proposing relevant laws or regulations and selecting proper pollution control technologies. The inventories of atmospheric arsenic emissions from coal combustion in China were evaluated by adopting the emission factor method based on fuel consumption. Arsenic emission sources were firstly classified into several categories by economic sectors, combustion types and pollution control technologies. Then, according to provincial coal consumption and averaged arsenic concentration in the feed fuel, the inventories of atmospheric arsenic emission from coal combustion in China in 2005 were established. Coal outputand consumption in China in 2005 were 2,119.8 and 2,099.8 Mt, respectively. The total emissions of arsenic released into the atmosphere in 2005 in China were estimated at about 1,564.4 t, and Shandong ranked the largest province with 144.4 t arsenic release, followed by Hunan (141.1 t), Hebei (108.5 t), Henan (77.7 t), and Jiangsu (77.0 t), which were mainly concentrated in the eastern and central provinces of China. The arsenic emissions were largely emitted by industry sector (818.8 t) and thermal power generation sector (303.4 t), contributing 52.3% and 19.4% of the totals, respectively. About 375.5 t arsenic was estimated to be released into the atmosphere in the form of gas phase in China in 2005, with a share of 24% of the totals. In general, arsenic pollution control from coal combustion should be highlighted for the power and industry sectors in the whole country. However, arsenic poisoning caused by residential coal burning should also be paid great attention in some areas such as Xinjiang, Gansu, Qinghai and Guishou.

  15. The effects of additive on limestone capturing sulfur during coal combustion

    SciTech Connect

    Chang, L.; Zhu, S.; Xie, K.; Liu, J.

    1998-12-31

    During high sulfur coal combustion, the desulfurization capacity of calcium-based sorbents has been investigated. The roles of additives in limestone were obvious and the capturing sulfur capacity of limestone containing additives is superior to that of only limestone under given reaction condition. The interaction mechanism of additive, limestone and SO{sub 2} was determined by DTA-TG and EA technology. These measurements showed that the reactions of limestone desulfurization primarily occurred at the first section of coal combustion, the active component is calcium carbonate and the reaction mechanism is not alike for additives existing or not.

  16. NOx reduction in combustion with concentrated coal streams and oxygen injection

    DOEpatents

    Kobayashi, Hisashi; Bool, III, Lawrence E.; Snyder, William J.

    2004-03-02

    NOx formation in the combustion of solid hydrocarbonaceous fuel such as coal is reduced by obtaining, from the incoming feed stream of fuel solids and air, a stream having a ratio of fuel solids to air that is higher than that of the feed steam, and injecting the thus obtained stream and a small amount of oxygen to a burner where the fuel solids are combusted.

  17. Modeling coal combustion behavior in an ironmaking blast furnace raceway: model development and applications

    SciTech Connect

    Maldonado, D.; Austin, P.R.; Zulli, P.; Guo B.

    2009-03-15

    A numerical model has been developed and validated for the investigation of coal combustion phenomena under blast furnace operating conditions. The model is fully three-dimensional, with a broad capacity to analyze significant operational and equipment design changes. The model was used in a number of studies, including: Effect of cooling gas type in coaxial lance arrangements. It was found that oxygen cooling improves coal burnout by 7% compared with natural gas cooling under conditions that have the same amount of oxygen enrichment in the hot blast. Effect of coal particle size distribution. It was found that during two similar periods of operation at Port Kembla's BF6, a difference in PCI capability could be attributed to the difference in coal size distribution. Effect of longer tuyeres. Longer tuyeres were installed at Port Kembla's BF5, leading to its reline scheduled for March 2009. The model predicted an increase in blast velocity at the tuyere nose due to the combustion of volatiles within the tuyere, with implications for tuyere pressure drop and PCI capability. Effect of lance tip geometry. A number of alternate designs were studied, with the best-performing designs promoting the dispersion of the coal particles. It was also found that the base case design promoted size segregation of the coal particles, forcing smaller coal particles to one side of the plume, leaving larger coal particles on the other side. 11 refs., 15 figs., 4 tabs.

  18. Airfoil cooling hole plugging by combustion gas impurities of the type found in coal derived fuels

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.; Lowell, C. E.

    1979-01-01

    The plugging of airfoil cooling holes by typical coal-derived fuel impurities was evaluated using doped combustion gases in an atmospheric pressure burner rig. Very high specific cooling air mass flow rates reduced or eliminated plugging. The amount of flow needed was a function of the composition of the deposit. It appears that plugging of film-cooled holes may be a problem for gas turbines burning coal-derived fuels.

  19. CHARACTERIZATION OF COAL COMBUSTION BY-PRODUCTS FOR THE RE-EVOLUTION OF MERCURY INTO ECOSYSTEMS

    SciTech Connect

    J.A. Withum; J.E. Locke; S.C. Tseng

    2005-03-01

    There is concern that mercury (Hg) in coal combustion by-products might be emitted into the environment during processing to other products or after the disposal/landfill of these by-products. This perception may limit the opportunities to use coal combustion by-products in recycle/reuse applications and may result in additional, costly disposal regulations. In this program, CONSOL conducted a comprehensive sampling and analytical program to include ash, flue gas desulfurization (FGD) sludge, and coal combustion by-products. This work is necessary to help identify potential problems and solutions important to energy production from fossil fuels. The program objective was to evaluate the potential for mercury emissions by leaching or volatilization, to determine if mercury enters the water surrounding an active FGD disposal site and an active fly ash slurry impoundment site, and to provide data that will allow a scientific assessment of the issue. Toxicity Characteristic Leaching Procedure (TCLP) test results showed that mercury did not leach from coal, bottom ash, fly ash, spray dryer/fabric filter ash or forced oxidation gypsum (FOG) in amounts leading to concentrations greater than the detection limit of the TCLP method (1.0 ng/mL). Mercury was detected at very low concentrations in acidic leachates from all of the fixated and more than half of the unfixated FGD sludge samples, and one of the synthetic aggregate samples. Mercury was not detected in leachates from any sample when deionized water (DI water) was the leaching solution. Mercury did not leach from electrostatic precipitator (ESP) fly ash samples collected during activated carbon injection for mercury control in amounts greater than the detection limit of the TCLP method (1.0 ng/mL). Volatilization tests could not detect mercury loss from fly ash, spray dryer/fabric filter ash, unfixated FGD sludge, or forced oxidation gypsum; the mercury concentration of these samples all increased, possibly due to

  20. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2002-02-05

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. Progress in the Sixth Quarter (January 1, 2002 through March 31, 2002) was slow because of slagging problems in the combustor. These required the combustor to be rebuilt, a job that is not yet complete. A paper describing our results heretofore has been accepted by the Journal Environmental Science and Technology.

  1. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2002-02-05

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. For the Fifth Quarter of this project we focus on determining whether certain trace metals are associated with certain major species, such as calcium and iron. To this end we present data showing correlations between As, Se,and Sb and major species, such as Ca and Fe. Conversely, lack of correlation between trace metals and elements, such as aluminum can also be used to infer lack of chemical association.

  2. Demonstration of post combustion NO{sub x} control technology on a pulverized coal, wet bottom utility boiler

    SciTech Connect

    Wallace, A.J.; Gibbons, F.X.; Roy, R.O.; O`Leary, J.H.; Knell, E.W.

    1995-12-31

    Public Service Electric and Gas (PSE and G) is evaluating the effectiveness of post-combustion NO{sub x} reduction technologies on a wet-bottomed, coal-fired utility boiler. The technologies under study are conventional urea-based SNCR, in-duct and air heater SCR, and a combination of SNCR and SCR. While SNCR and, to a limited extent, SCR have been used on coal-fired boilers, these processes have not been demonstrated on a unit with the same configuration as the wet-bottom, continuous slagging, pulverized coal furnaces operated at PSE and G`s Mercer Generating Station. This paper summarizes the results of the three programs and comparisons to baseline NO{sub x}. Of particular interest was the relationship of each technology to operation of the unit. The ability to maintain low NO{sub x} emissions while varying loads and fuels, as well as determining ammonia slip and pressure drop was also demonstrated.

  3. Numerical simulation of ash vaporization during pulverized coal combustion in the laboratory-scale single-burner furnace

    SciTech Connect

    Jiancai Sui; Minghou Xu; Jihua Qiu; Yu Qiao; Yun Yu; Xiaowei Liu; Xiangpeng Gao

    2005-08-01

    CFD tools have been developed to effectively simulate complex, reacting, multiphase flows that exist in utility boilers. In this paper, a model of ash vaporization was established and integrated into a self-developed CFD code to predict ash vaporization in the coal combustion process. Experimental data from a single-particle combustion was used to validate the above model. The calibrated model was then applied to simulate the ash vaporization in a 92.9 kW laboratory-scale single-burner furnace. The effects of different combustion conditions, including air staging, on the ash vaporization were investigated. The results showed that the fraction of ash vaporization is mostly sensitive to coal particle temperature. Ash vaporization primarily occurred after a short interval along the coal particle trajectories when the particle temperatures increased to 1800 K. Air staging influenced the ash vaporization by changing the gas temperature distribution in the furnace. The simulation results showed that the more extreme the staging condition, the lower the overall peak temperature, and hence the lower the amount of ash vaporization. 26 refs., 9 figs.

  4. Fuel and ash characterization of Indian coal for their suitability in fluidized bed combustions

    SciTech Connect

    Palit, A.; Mandal, P.K.

    1995-12-31

    The fluidized bed combustion (FBC) technology is now fully recognized and units with high capacity are in operation the world over. In the Indian context, now is the time to exploit the fluidized bed technology for electric power generation, which may nurture the poor grade Indian coal in a better way as compared to that of pulverized fuel fired system. The present paper deals with Indian coals and ash characterization and the effect of various coal properties on combustion in a fluidized bed like moisture, mineral/ash content, volatile matter, maceral structure (petrographic properties), swelling/caking index, ash properties including ash fusion temperature, etc. and their critical discussion based on experimental investigations with Indian coals and also their suitability in FBC. In addition, the experience with a 10 MW FBC unit in India with problems and parameters, some experimental investigations on suitability of Lalmatia coal (Rajmahal coal field) in fluidized bed combustion and pollutant formations vis-a-vis control (NOx, SOx, etc.) have also been discussed.

  5. Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-)combustion fly ashes.

    PubMed

    Alvarez-Ayuso, E; Querol, X; Plana, F; Alastuey, A; Moreno, N; Izquierdo, M; Font, O; Moreno, T; Diez, S; Vázquez, E; Barra, M

    2008-06-15

    The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 degrees C) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut für Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80

  6. Measurement and modeling of advanced coal conversion processes. 19th quarterly report, April 1, 1991--June 30, 1991

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S.

    1991-09-25

    The objectives of this study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. (VC)

  7. EXXON donor solvent coal liquefaction process

    NASA Technical Reports Server (NTRS)

    Epperly, W. R.; Swabb, L. E., Jr.; Tauton, J. W.

    1978-01-01

    A solvent coal liquefaction process to produce low-sulfur liquid products from a wide range of coals is described. An integrated program of laboratory and engineering research and development in conjunction with operation of a 250 T/D pilot plant is discussed.

  8. Combustion system processes leading to corrosive deposits

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Rosner, D. E.

    1981-01-01

    Degradation of turbine engine hot gas path components by high temperature corrosion can usually be associated with deposits even though other factors may also play a significant role. The origins of the corrosive deposits are traceable to chemical reactions which take place during the combustion process. In the case of hot corrosion/sulfidation, sodium sulfate was established as the deposited corrosive agent even when none of this salt enters the engine directly. The sodium sulfate is formed during the combustion and deposition processes from compounds of sulfur contained in the fuel as low level impurities and sodium compounds, such as sodium chloride, ingested with intake air. In other turbine and power generation situations, corrosive and/or fouling deposits can result from such metals as potassium, iron, calcium, vanadium, magnesium, and silicon.

  9. Sandia Combustion Research: Technical review

    SciTech Connect

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  10. Fly ashes from coal and petroleum coke combustion: current and innovative potential applications.

    PubMed

    González, Aixa; Navia, Rodrigo; Moreno, Natalia

    2009-12-01

    Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations. PMID:19423583

  11. Fly ashes from coal and petroleum coke combustion: current and innovative potential applications.

    PubMed

    González, Aixa; Navia, Rodrigo; Moreno, Natalia

    2009-12-01

    Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations.

  12. Combustion characterization of the blend of plant coal and recovered coal fines. Final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Singh, S.; Scaroni, A.; Miller, B.; Choudhry, V.

    1992-12-31

    The overall objective of this proposed research program was to determine the combustion characteristics of the blend derived from mixing a plant coal and recovered and clean coal fines from the pond. During this study, one plant coal and three blend samples were prepared as 100% plant coal, 90% plant coal/10% fines, 85% plant coal/15% fines, and 80% plant coal /20% fines with a particle size distribution of 70% passing through {minus}200 mesh size. The plant coal and recovered coal fines were obtained from the Randolph Preparation Plant of Peabody Coal Co., Marissa, IL. These samples` combustion behavior will be examined in two different furnaces at Penn State University, i.e., a down-fired furnace and a drop-tube furnace. The down-fired furnace was used mainly to measure the emissions and ash deposition study, while the drop tube furnace was used to determine burning profile, combustion efficiency, etc. The burning profile of the plant coal and the three blends was determined in a thermogravimetric analyzer. Results indicated slower burning of the blends due to low volatile matter and oxidized coal particles. Combustion emissions of these samples were determined in the down-fired combustor, while relative ignition temperatures were determined in the drop tube furnace. Chemical composition of ashes were analyzed to establish a correlation with their respective ash fusion temperatures. Overall study of these samples suggested that the blended samples had combustion properties similar to the original plant coal. In other words, flames were stable under identical firing rates of approximately 200,000 Btu`s/hr and 25% excess air. CO, NO{sub x}, and SO{sub x}, were similar to each other and within the experimental error. Combustion efficiency of 99{sup +}% was achievable. Ash chemical analysis of each sample revealed that slagging and fouling should not be different from each other.

  13. Internal Heterogeneous Processes in Aluminum Combustion

    NASA Technical Reports Server (NTRS)

    Dreizin, E. L.

    1999-01-01

    This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (< 1 %) regions are identified within the particles using back-scattered electron imaging and WDS. During stage II, oscillations are observed in particle radiation and the flame and smoke cloud are distorted from their original spherically-symmetric shape. In stage III, particle radiation continues to exhibit oscillations, but its radiation intensity drops and remains at a nearly constant level. The measured temperature decreases to about 2300 K. Also, larger changes in particle velocities are observed, and oxide caps are found on quenched particle surfaces. While these results showed the correlation between the aluminum particle combustion behavior and the

  14. Assessment of groundwater quality impacts due to use of coal combustion byproducts to control subsidence from underground mines.

    PubMed

    Singh, G; Paul, B C

    2001-06-01

    Coal combustion byproducts are to be placed in an underground coal mine to control subsidence. The materials were characterized to determine potential groundwater impacts. No problems were found with respect to heavy or toxic metals. Coal combustion byproduct leachates are high in dissolved solids and sulfates. Chloride and boron from fly ash may also leach in initially high concentrations. Because the demonstration site is located beneath deep tight brine-bearing aquifers, no problems are anticipated at the demonstration site. PMID:11485225

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 11, October--December 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1992-03-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of beneficiated coal-based fuels (BCFs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors perform parts of the test work are the Massachusetts Institute of Technology Physical Science, Inc. Technology Company and the University of North Dakota Energy and Environmental Research Center. Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for full-scale tests. Approximately nine BCFs will be in dry ultra fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements. During the third quarter of 1991, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed analyses of the samples from the pilot-scale ash deposition tests of three Freeport Pittsburgh 8 fuels; conducted pilot-scale combustion and ash deposition tests of a fresh batch of Upper Freeport parent coal in the CE fireside Performance Test Facility; and completed editing of the fourth quarterly report and sent it to the publishing office.

  16. Calderon coal gasification Process Development Unit design and test program

    SciTech Connect

    Calderon, A.; Madison, E.; Probert, P.

    1992-11-01

    The Process Development Unit (PDU) was designed and constructed to demonstrate the novel Calderon gasification/hot gas cleanup process. in the process, run-of-mine high sulfur coal is first pyrolyzed to recover a rich gas (medium Btu gas), after which the resulting char is subjected to airblown gasification to yield a lean gas (low Btu gas). The process incorporates a proprietary integrated system for the conversion of coal to gases and for the hot cleanup of the gases which removes both particulate and sulfur components of the gaseous products. The yields are: a syngas (CO and H{sub 2} mix) suitable for further conversion to liquid fuel (e.g. methanol/gasoline), and a lean gas suitable to fuel the combustion turbine of a combined cycle power generation plant with very low levels of NO{sub x} (15 ppmv). The fused slag (from the gasified char ash content) and the sulfur recovered during the hot gas cleanup will be sold as by-products. The small quantity of spent sorbent generated will be combined with the coal feed as a fluxing agent for the slag. The small quantity of wastewater from slag drainings and steam generation blowdown will be mixed with the coal feed for disposal. The Calderon gasification/hot gas cleanup, which is a completely closed system, operates at a pressure suitable for combined cycle power generation.

  17. Calderon coal gasification Process Development Unit design and test program

    SciTech Connect

    Calderon, A.; Madison, E.; Probert, P.

    1992-01-01

    The Process Development Unit (PDU) was designed and constructed to demonstrate the novel Calderon gasification/hot gas cleanup process. in the process, run-of-mine high sulfur coal is first pyrolyzed to recover a rich gas (medium Btu gas), after which the resulting char is subjected to airblown gasification to yield a lean gas (low Btu gas). The process incorporates a proprietary integrated system for the conversion of coal to gases and for the hot cleanup of the gases which removes both particulate and sulfur components of the gaseous products. The yields are: a syngas (CO and H[sub 2] mix) suitable for further conversion to liquid fuel (e.g. methanol/gasoline), and a lean gas suitable to fuel the combustion turbine of a combined cycle power generation plant with very low levels of NO[sub x] (15 ppmv). The fused slag (from the gasified char ash content) and the sulfur recovered during the hot gas cleanup will be sold as by-products. The small quantity of spent sorbent generated will be combined with the coal feed as a fluxing agent for the slag. The small quantity of wastewater from slag drainings and steam generation blowdown will be mixed with the coal feed for disposal. The Calderon gasification/hot gas cleanup, which is a completely closed system, operates at a pressure suitable for combined cycle power generation.

  18. Emission, distribution and toxicity of polycyclic aromatic hydrocarbons (PAHs) during municipal solid waste (MSW) and coal co-combustion.

    PubMed

    Peng, Nana; Li, Yi; Liu, Zhengang; Liu, Tingting; Gai, Chao

    2016-09-15

    Emission and distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) were investigated during municipal solid waste (MSW) and coal combustion alone and MSW/coal blend (MSW weight fraction of 25%) co-combustion within a temperature range of 500°C-900°C. The results showed that for all combustion experiments, flue gas occupied the highest proportion of total PAHs and fly ash contained more high-ring PAHs. Moreover, the 3- and 4-ring PAHs accounted for the majority of total PAHs and Ant or Phe had the highest concentrations. Compared to coal, MSW combustion generated high levels of total PAHs with the range of 111.28μg/g-10,047.22μg/g and had high toxicity equivalent value (TEQ). MSW/coal co-combustion generated the smallest amounts of total PAHs and had the lowest TEQ than MSW and coal combustion alone. Significant synergistic interactions occurred between MSW and coal during co-combustion and the interactions suppressed the formation of PAHs, especially hazardous high-ring PAHs and decreased the TEQ. The present study indicated that the reduction of the yield and toxicity of PAHs can be achieved by co-combustion of MSW and coal.

  19. Testing of FMI's Coal Upgrading Process

    SciTech Connect

    Vijay Sethi

    2009-03-21

    WRI and FMI have collaborated to develop and test a novel coal upgrading technology. Proprietary coal upgrading technology is a fluidized bed-based continuous process which allows high through-puts, reducing the coal processing costs. Processing is carried out under controlled oxidizing conditions at mild enough conditions that compared to other coal upgrading technologies; the produced water is not as difficult to treat. All the energy required for coal drying and upgrading is derived from the coal itself. Under the auspices of the Jointly Sponsored Research Program, Cooperative Agreement DE-FC26-98FT40323, a nominal 400 lbs/hour PDU was constructed and operated. Over the course of this project, several low-rank coals were successfully tested in the PDU. In all cases, a higher Btu, low moisture content, stable product was produced and subsequently analyzed. Stack emissions were monitored and produced water samples were analyzed. Product stability was established by performing moisture readsorption testing. Product pyrophobicity was demonstrated by instrumenting a coal pile.

  20. Direct combustion of coal. Hearing before the Subcommittee on Energy Development and Applications of the Committee on Science and Technology, US House of Representatives, Ninety-Seventh Congress, First Session, December 10, 1981

    SciTech Connect

    Not Available

    1982-01-01

    It is felt that US domestic coal is still an under-utilized resource because of uncertainties about future electricity demand and about the economic attractiveness of coal compared with oil, gas, and conservation, the frequent changes in government policy toward coal use, the increasing limitation of coal use to larger facilities and uncertainities in the environmental and health impacts associated with coal use. Acid rain and its impact on the fish population was discussed and coal washing was recommended as the logical first step to compat the problem. The current state of development, the potential, and the problems of atmospheric fluidized bed combustion technology were described. it was felt that the government should help fund demonstration plants to encourage coal use. Coal cleaning technology and its applications to the electric utility industry was discussed emphasizing its cost effectiveness and environmental advantages. Research programs sponsored by the Department of Energy on coal combustion were seen as necessary to the development of combustion technology because of everchanging environmental policies that can render new equipment obsolete with a stroke of a pen and because of the 8 to 10 years development time now needed for new technology. Appendices contain descriptions of the Otisca Process and T-Process for coal cleaning, Johnston multi-fuel fluidized bed combustion packaged boilers, and fluidized bed boiler applications. (CKK)