Science.gov

Sample records for coal combustion effects

  1. [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

  2. 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.

  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. 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.

  5. [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. PMID:11987396

  6. 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...

  7. 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.

  8. 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.

  9. 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

  10. 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

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

    SciTech Connect

    Zygourakis, K.

    1992-01-01

    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--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). (VC)

  12. 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).

  13. Effects of calcium magnesium acetate on the combustion of Coal-Water Slurries

    SciTech Connect

    Not Available

    1990-01-01

    The general objective of the project is to investigate the combustion behavior of single Coal-Water Slurry particles burning at high temperature environments. Both uncatalyzed as well catalyzed CWS drops with Calcium Magnesium Acetate (CMA) catalyst will be investigated. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion.

  14. 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.

  15. 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.

  16. Assessment of the effect of high ash content in pulverized coal combustion

    SciTech Connect

    Jayanti, S.; Maheswaran, K.; Saravanan, V.

    2007-05-15

    The existing literature on CFD-based coal combustion modelling is applicable mainly for coals of low ash content and the calculations are done on an ash-free basis. In Indian coals, the ash content may be significantly higher, up to 40% or more. Studies reported in the literature show that the mineral matter in the coal may have a number of effects on the combustion characteristics. In the present study, a sensitivity analysis is performed, using the CFD code CFX of AEA Technology, on the likely effect of ash content on the char reactivity, oxygen diffusion rate for char combustion and on the radiative heat transfer parameters. The results show that the effect of enhanced char reactivity is negligible whereas reduced oxygen diffusion rates due to a thicker ash layer may result in a significant reduction in char oxidation rates with a resultant decrease in the peak temperature in the furnace. The global parameters such as the peak temperature and the flue gas temperature remain relatively insensitive to the presence of high ash content. These results are consistent with the experimental observations of Kurose et al. . Kurose, M. Ikeda, H. Makino, Combustion characteristics of high ash coal in pulverized coal combustion, J. Fuel 80 (2001) 1447-1455).

  17. Fluidized bed combustion of coal

    NASA Astrophysics Data System (ADS)

    Tatebayashi, J.; Okada, Y.; Yano, K.; Takada, T.; Handa, K.

    The effect of various parameters on combustion efficiency, desulfurization efficiency and NO emission in fluidized bed combustion of coal were investigated by using two test combustors whose sectional areas were 200 mm and 500 mm square. It has been revealed that by employing two-stage combustion and setting the primary air ratio, secondary air injection height and other parameters to optimum levels, NO emission can be greatly reduced while barely impairing combustion efficiency or desulfurization efficiency. Also, NO emission of less than 50 ppm and desulfurization efficiency of as high as 93% were achieved. These results have ensured good prospects for the development of a coal combustion boiler system which can satisfy the strictest environmental protection regulations, without installing special desulfurization and de-NO(X) facilities.

  18. 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.

  19. 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.

  20. 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.

  1. Effect of the size distribution of coal on fluidized-bed combustion

    SciTech Connect

    Hirama, T.; Hosoda, H.; Nishizaki, H.; Chiba, T.; Kobayashi, H.

    1984-07-01

    To study the effect of the particle-size distribution on its combustion characteristics, coal was burned in a 0.25 m-square fluidized-bed combustor with a 3-m freeboard. A higher fines content increased the loss of unburned coal by elutriation, but reduced the loss from overflow from the bed surface. The overall combustion efficiency varied only slightly with the size distribution; the efficiency of combustion within the bed was reduced, but more combustion took place in the freeboard, both for 9.5-25 mm particles, owing to segregation in the bed, and for <2 mm particles, owing to elutriation. NO/SUB/x emission for two-stage combustion with these two size ranges was considerably higher than for particles within the broader range <25 mm. Since segregation of coarse particles and elutriation of unburned finer particles increase NO/SUB/x emission and reduced the bed combustion efficiency, it is desirable to use coal with a broad particle-size distribution.

  2. COMBUSTION OF HYDROTHERMALLY TREATED COALS

    EPA Science Inventory

    The report gives results of an evaluation of: (1) the relationship of the combustion characteristics of hydrothermally treated (HTT) coals to environmental emissions, boiler design, and interchangeability of solid fuels produced by the Hydrothermal Coal Process (HCP) with raw coa...

  3. Electrochemical protection of coal from spontaneous combustion

    SciTech Connect

    Aleksandrov, I.V.; Burkov, P.A.; Kamneva, A.I.; Khokhlov, Yu.I.

    1984-01-01

    An electrochemical method is described for the protection of coal stocks from self-heating and spontaneous combustion. Cathodic polarisation is effected by an external source of direct current using contact electrodes situated in the coal. Practically complete suppression of self-heating is claimed for 450-500 m/sup 3/ volumes of coal at an insignificant energy cost.

  4. Effect of organic calcium compounds on combustion characteristics of rice husk, sewage sludge, and bituminous coal: thermogravimetric investigation.

    PubMed

    Zhang, Lihui; Duan, Feng; Huang, Yaji

    2015-04-01

    Experiments were conducted in a thermogravimetric analyzer to assess the enhancement of combustion characteristics of different solid fuels blended with organic calcium compounds (OCCs). Rice husk, sewage sludge, and bituminous coal, and two OCC were used in this study. Effect of different mole ratios of calcium to sulfur (Ca/S ratio) on the combustion characteristics were also investigated. Results indicated that combustion performance indexes for bituminous coal impregnated by OCC were improved, however, an inverse trend was found for sewage sludge because sewage sludge has lower ignition temperature and higher volatile matter content compared to those of OCC. For rice husk, effect of added OCC on the combustion characteristics is not obvious. Different solid fuels show different combustion characteristics with increases of Ca/S ratio. The maximum combustion performance indexes appear at Ca/S ratios of 1:1, 2:1, and 3:1 for OCC blended with Shenhua coal, rice husk, and sewage sludge, respectively. PMID:25638405

  5. 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

  6. ULTRAFINE ASH AEROSOLS FROM COAL COMBUSTION: CHARACTERIZATION AND HEALTH EFFECTS

    EPA Science Inventory

    Ultrafine coal fly ash particles, defined here as those with diameters less than 0.5 micrometer, typically comprise less than 1% of the total fly ash mass. These particles are formed almost exclusively through ash vaporization, nucleation, and coagulation/condensation mechanisms,...

  7. 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.

  8. The effect of upgrading processes on combustion characteristics of Berau coal

    SciTech Connect

    Datin Fatia Umar; Binarko Santoso; Hiromoto Usui

    2007-12-15

    Indonesian coal was upgraded by upgraded brown coal (UBC), hot water drying (HWD), and steam drying (SD) processes to study the combustion characteristics of this coal. The differential thermal-thermogravimetric analysis (DTA-TG) was carried out to obtain some combustion parameters, such as, ignition temperature (T{sub ig}), maximum combustion rate temperature (T{sub max}), maximum combustion rate (R{sub max}), char burn-out temperature (T{sub bo}), and ash yield. The differential thermal analyzer (DTA) curve can be used to estimate the heat released during the combustion process, which corresponds to the high heating value of the coal. The results show that the combustion characteristics of HWD and SD processes are much better than those of the UBC process. This is because the UBC process was conducted at lower temperature and pressure. 11 refs., 2 figs., 3 tabs.

  9. 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.

  10. Effect of additives on the reduction of PM2.5 emissions during pulverized coal combustion

    SciTech Connect

    Yoshihiko Ninomiya; Qunying Wang; Shuyin Xu; Katsuharu Mizuno; Isao Awaya

    2009-07-15

    Two bituminous coals used in coal-fired power plants were mixed with either Ca- or Mg-based chemical additives. Coals and the mixtures were burnt in a laboratory-scale drop tube furnace, respectively. The impact of the additives on the transformations of coal minerals, as well as on the emissions of particulate matter with an aerodynamic diameter smaller than 2.5 {mu}m (PM2.5), was investigated. The generated ash particles were collected using a cyclone combined with a low-pressure impactor. The physical and chemical properties of these ash particles were analyzed. The results indicate that the addition of chemical additives can affect the mineral transformation process, and thus, control the emissions of PM2.5 and PM1 during combustion. In particular, additives have a considerable impact on the particle size distribution and chemical composition of PM, wherein it improves the degree of coalescence of submicron and fine mineral particles, which reduces PM2.5 emissions. The effects of additive on the reduction of PM2.5 emissions depend on the type of coals being used. 17 refs., 8 figs., 3 tabs.

  11. 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.

  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. 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 wit Calcium Magnesium Acetate (CMA) catalyst will be studied. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion. To help achieve these objectives the following project tasks were carried over this 8th three-month period. Project Tasks: Work on two major tasks was conducted over this period: (1) Trouble-sooting of the pyrometer calibration equipment and then re-calibrating the pyrometer with two different NIST lamps. (2) Production and characterization of CaO particles derived from Calcium Magnesium Acetate. These particles are very promising SO{sub 2} sorbents. 10 figs.

  14. Health Effects of Subchronic Inhalation of Simulated Downwind Coal Combustion Emissions

    SciTech Connect

    Joe Mauderly

    2009-01-07

    The purpose of this project was to conduct a comprehensive laboratory-based evaluation of selected respiratory and cardiac health hazards of subchronic (up to 6 months) inhalation of simulated key components of 'downwind plume' emissions of coal combustion. This project was performed as an integral part of a joint government-industry program termed the 'National Environmental Respiratory Center' (NERC), which is aimed at disentangling the roles of different physical-chemical air pollutants and their sources in the health effects associated statistically with air pollution. The characterization of the exposure atmosphere and the health assays were identical to those employed in the NERC protocols used to evaluate other pollution source emissions, such as diesel, gasoline, and wood combustion. The project had two phases, each encompassing multiple tasks. Guidelines for the composition of the exposure atmosphere were set by consensus of an expert workshop. Development of the capability to generate the exposure atmosphere and pilot studies of the comparative exposure composition using two coal types were accomplished in Phase 1. In Phase 2, the toxicological study was conducted using Powder River Basin Sub-bituminous coal. NETL provided 50% support for the work in Phase 1 and had intended to provide 20% support for the work in Phase 2. Phase 1 is completed and Phase 2 is in the final stages. All animal exposures were completed without incident, and the composition of the exposure atmospheres met the targets. All of the health sample collections are completed, but some samples remain to be analyzed. Data summaries and final statistical analysis of results remain to be completed. The goal is to submit all publications before the end of FY-08. Repeated exposure to simulated downwind coal emissions caused some significant health effects, but the number of effects tended to be fewer than those caused by the other NERC exposures (diesel and gasoline emissions and hardwood

  15. ENVIRONMENTAL EFFECTS OF WESTERN COAL COMBUSTION. PART III. THE WATER QUALITY OF ROSEBUD CREEK, MONTANA

    EPA Science Inventory

    The results of a study on Rosebud Creek, Montana, designed to assess the impacts on water quality of surface coal mining and/or coal combustion at Colstrip are summarized herein. A general degradation of water quality has been observed along the stream course but direct impacts o...

  16. 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...

  17. ENVIRONMENTAL EFFECTS OF WESTERN COAL COMBUSTION. PART IV. CHEMICAL AND PHYSICAL CHARACTERISTICS OF COAL FLY ASH

    EPA Science Inventory

    Coal fly ashes from different sources were extensively studied. Fly ash consists of as many as 12 different particle types, made up mainly of Si, Al, Ca, K, Na, and Fe. Many p potentially volatile trace elements (As, Se, Ga, In, Pb, Cd) are always preferentially associated with m...

  18. EFFECTS OF CHANGING COALS ON THE EMISSIONS OF METAL HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    The report discusses tests conducted at EPA's Air Pollution Prevention and Control Division to evaluate the effects of changing coals on emissions of metal hazardous air pollutants from coal-fired boilers. Six coals were burned in a 29 kW (100,000 Btu/hr) down-fired combustor und...

  19. Effects of effluents of coal combustion and gasification upon lung structure and function. Annual report

    SciTech Connect

    Hinton, D.E.

    1980-01-01

    The overall objective of the proposed research is to correlate both structural and functional alterations in cells and tissues of the lung brought about by exposure to fluidized bed combustion and fixed bed gasification effluents and reagent grade oxides of metals known to be associated with coal combustion gasification. Projected milestones are described. Progress during the first year in setting up aerosol exposure facilities, intratracheal instillations, pulmonary mechanics, and morphometric examinations is reported. (DMC)

  20. 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.

  1. 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...

  2. Reduction of spontaneous combustion of coal

    SciTech Connect

    Burns, E.J.

    1982-05-25

    A composition for the prevention of spontaneous combustion of coal is described which is comprised of at least about 2 percent of polyethylene oxide and the balance water. Also described is a method for reducing the spontaneous combustion tendency of coal by contacting coal with the above composition and then drying the coal.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. The effect of potassium bromide and sodium carbonate on coal char combustion reactivity.

    SciTech Connect

    Molina, Alejandro; Shaddix, Christopher R.; Blevins, Linda Gail; Murphy, Jeffrey J.

    2003-12-01

    The addition of halogens, particularly iodine, to the gas during coal char oxidation has been used in previous studies to quench gas-phase chemistry, thereby allowing one to separate the effects of homogeneous and heterogeneous reactions. Halogen addition suppresses the gas-phase radicals to near-equilibrium levels. A similar effect can be expected from other compounds with high efficiency as fire suppressants, such as alkali metals. The effectiveness of the use of additives in distinguishing homogeneous and heterogeneous reactions during char oxidation relies on the assumption that radicals are suppressed while heterogeneous reactions occurring on the char surface are not affected. The present work tests this assumption for potassium bromide (KBr) and sodium carbonate (Na{sub 2}CO{sub 3}) reacting with a pulverized eastern bituminous coal char during oxidation. An increase in CO and a slight reduction in particle temperature were observed with the addition of KBr, consistent with known effects of halogens on gas-phase chemistry. An increase in particle size was also observed with the KBr addition. This observation and the results of model calculations suggest that there is significant incorporation of liquid KBr on the char surface under the conditions examined. With Na{sub 2}CO{sub 3} addition, the particle temperature did not change, the particle size showed a slight decrease, and CO production increased. Although the mechanisms for Na interaction with radicals at combustion conditions are not well established, char oxidation modeling suggests that a decrease in OH concentration in the particle boundary layer is the cause for the observed increase in CO production. It is concluded that Na{sub 2}CO{sub 3} has clear advantages over KBr for inhibiting gas-phase chemistry without affecting char oxidation for the conditions investigated here.

  8. 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.

  9. [Retention of selenium volatility using lime in coal combustion].

    PubMed

    Zhang, J; Ren, D; Zhong, Q; Xu, F; Zhang, Y; Yin, J

    2001-05-01

    For understanding the volatility of selenium, the effect of the contents of exchangeable cations of coal on it, and the retention of selenium using CaO in coal combustion, the sequential chemistry extraction, the fixed bed and circulating fluidized bed (CFB) combustion, X-ray diffraction (XRD) and atomic fluorescence spectrometry (AFS) were undertaken. The results showed that the volatility of selenium was more than 97% in coal combustion at 815 degrees C, and the volatility of selenium was affected by the content of exchangeable cations of coal in low-middle temperature. It was identified that lime can restrain the volatility of selenium. In fixed bed combustion of coal, the retention rates of selenium volatility were between 11.6% and 50.7% using lime. In circulating fluidized bed combustion of coal, partitioning of selenium changed very much in ash of different size fraction between without lime and with lime. Comparing with combustion without lime, the content of selenium in ash from chimney was less than fourth times and that in leaching water from chimney decreased by two orders of magnitude using lime. Retention of selenium volatility using lime is so effective in coal combustion, especially in CFB combustion of coal. PMID:11507891

  10. Inhibition of spontaneous combustion of coal

    SciTech Connect

    Smith, A.C.; Miron, Y.; Lazzara, C.P.

    1988-01-01

    This report describes laboratory studies conducted to evaluate the effectiveness of 10 additives to inhibit the self-heating of coal. Aqueous additive solutions were applied to a bituminous coal with a high spontaneous combustion potential, and the minimum, self-heating temperatures (SHT's) of the dired coal-additive mixtures were determined in the Bureau's adiabatic heating oven. The relative effectiveness of the additives was determined by the observed changes in the minimum SHT's of the mixtures or by the time required for the sample temperature to reach 150{degrees}C, compared with the untreated coal and coal-water blank. Sodium nitrate, sodium chloride, and calcium carbonate were found to be the most effective inhibitors, followed by ammonium dihydrogen phosphate, calcium chloride ammonium chloride, sodium acetate, and potassium chloride. Two additives, sodium formate and sodium phosphate, promoted the self-heating process. Differential scanning calorimetry experiments on the coal-additive mixtures show that reactions occured between the coal and some of the additives, but these reactions did not infuluence the self-heating process.

  11. Effects of pretreatment of coal by CO{sub 2} on nitric oxide emission and unburned carbon in various combustion environments

    SciTech Connect

    Gathitu, B.B.; Chen, W.Y.

    2009-12-15

    Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO{sub 2} on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI.

  12. Statistical kinetics for pulverized coal combustion

    SciTech Connect

    Hurt, R.H.; Lunden, M.M.; Brehob, E.G.; Maloney, D.J.

    1996-06-01

    Coal is a heterogeneous substance whose structure and properties are highly variable on the length scale of the particle sizes used in suspension-fired combustion systems. For certain applications the statistical variations among particles can play an important role. In this paper, three specialized, single-particle techniques are applied to quantify the variations in combustion reactivity and char particle density within pulverized char particle populations. Reactivity variations are investigated through captive particle imaging experiments and entrained flow reactor experiments employing single-particle optical diagnostics. Single-particle density variations are determined directly by a novel technique based on an electrodynamic microbalance equipped with an automated video imaging and image processing system. From these data, a coal-general statistical kinetic model is developed and validated against a large set of single-particle temperature measurements for ten coals of various rank burning in three different combustion environments. The model incorporates a single empirical parameter describing the heterogeneity in reactivity and can adequately describe the entire database using a single coal-independent value of this parameter. The use of the model is demonstrated in a series of numerical simulations of complete burnout process for size-classified and polydisperse fuel samples. The simulations show that incorporating statistical kinetics has an important effect on burnout predictions in certain cases, the importance increasing with decreases in temperature, mean reactivity, and breadth of the particle size distribution. 32 refs.

  13. Adverse effects of coal combustion related fine particulate matter (PM2.5) on nematode Caenorhabditis elegans.

    PubMed

    Sun, Lingmei; Lin, Zhiqing; Liao, Kai; Xi, Zhuge; Wang, Dayong

    2015-04-15

    The toxic effects of coal combustion related fine particulate matter (PM2.5), collected from Datong, Shanxi province, China, on nematode Caenorhabditis elegans were investigated. Exposure to PM2.5 resulted in deficits in development, reproduction, locomotion behavior, and lifespan, and induction of intestinal autofluorescence or reactive oxygen species (ROS) production. Prolonged exposure to PM2.5 led to more severe toxicity on nematodes than acute exposure. In addition, exposure to PM2.5 induced altered expression patterns of genes required for the control of oxidative stress. Reduction in mean defecation cycle length and developmental deficits in AVL and DVB neurons, which are involved in the control of defecation behavior, were also triggered by PM2.5 exposure. Thus, oxidative stress and abnormal defecation behavior may contribute greatly to the toxicity of coal combustion related PM2.5 in nematodes. The results also imply that the long-term adverse effects of coal combustion related PM2.5 on environmental organisms should be carefully considered. PMID:25625637

  14. TECHNOLOGIES FOR CONTROLLING POLLUTANTS FROM COAL COMBUSTION

    EPA Science Inventory

    The paper is an overview of EPA's efforts in developing technology for controlling pollutants from coal combustion. SO2, NOx, and particles are the predominant pollutants emitted from the combustion of coal. One goal of current EPA research and development is to reduce the costs ...

  15. COMBUSTION GENERATED PARTICLES - EXAMINING BOTH DIESEL AND COAL PM CHARACTERIZATION AND HEALTH EFFECTS

    EPA Science Inventory

    Processes that form fine and ultrafine particulate matter (PM) are of regulatory interest because there is evidence that these particles cause adverse health effects. Different fuels and combustion technologies produce particles with widely different physical and chemical propert...

  16. Effects of calcium magnesium acetate on the combustion of Coal-Water Slurries. Second quarterly project status report, 1 December 1989--28 February 1990

    SciTech Connect

    Not Available

    1990-12-31

    The general objective of the project is to investigate the combustion behavior of single Coal-Water Slurry particles burning at high temperature environments. Both uncatalyzed as well catalyzed CWS drops with Calcium Magnesium Acetate (CMA) catalyst will be investigated. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion.

  17. Effects of calcium magnesium acetate on the combustion of coal-water slurries. Ninth quarterly project status report, 1 September 1991--30 November 1991

    SciTech Connect

    Levendis, Y.A.

    1991-12-31

    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.

  18. Effectiveness of calcium magnesium acetate as an SO[sub x] sorbent in coal combustion

    SciTech Connect

    Levendis, Y.A.; Zhu, W.; Wise, D.L. ); Simons, G.A. )

    1993-05-01

    A fundamental study was conducted on the effectiveness of the chemical calcium magnesium acetate (CMA) as a sulfur capture agent during combustion of pulverized coal. It was based on high-temperature laboratory-bench experiments with the scope of exploring the use of CMA as a dry scrubbing'' medium for in-boiler injection. Two methods of CMA introduction in the furnace were considered: dry-spraying fine powders of the chemical and wet-spraying aqueous solutions to generate fine aerosols. It considered conditions pertinent to post-flame in-boiler injection of CMA to identify optimum temperatures and residence times. In addition to the versatility of the water-soluble CMA to enable spray drying injection and therefore eliminate grinding costs, there are other attractive features. Mainly, its ability to form highly cenospheric, popcorn''-like, oxide particles on heating to high temperatures. These cenospheres possess thin, porous walls with blowholes that enable penetration of the SO[sub 2] in the interior of the particle which promotes high sorbent utilization. SO[sub 2] captures in the order of 90% were achieved with dry-injection of the chemical at furnace gas temperatures of about 1,000[degree]C, a Ca/S ratio of 2, and particle size of [approximately] 50[mu]m. Moreover, CMA was superior (by over 40%) to either CaCO[sub 3] or Ca(OH)[sub 2] in sulfur capture effectiveness per unit mass of calcium. This commercially obtained CMA was even superior to reagent-grade calcium acetate (by as much as 30%), again per unit mass of calcium. The utilization of CMA and calcium acetate depended on the cenosphere wall thickness, rather than the particle size and, thus, outperformed other sorbents regardless of the size of the resulting oxide particles.

  19. PILOT-SCALE STUDY OF THE EFFECT OF SELECTIVE CATALYTIC REDUCTION CATALYST ON MERCURY SPECIATION IN ILLINOIS AND POWDER RIVER BASIN COAL COMBUSTION FLUE GASES

    EPA Science Inventory

    A study was conducted to investigate the effect of selective catalytic reduction (SCR) catalyst on mercury (Hg) speciation in bituminous and subbituminous coal combustion flue gases. Three different Illinois Basin bituminous coals (from high to low sulfur and chlorine) and one Po...

  20. Oxy-fuel combustion of coal and biomass, the effect on radiative and convective heat transfer and burnout

    SciTech Connect

    Smart, John P.; Patel, Rajeshriben; Riley, Gerry S.

    2010-12-15

    This paper focuses on results of co-firing coal and biomass under oxy-fuel combustion conditions on the RWEn 0.5 MWt Combustion Test Facility (CTF). Results are presented of radiative and convective heat transfer and burnout measurements. Two coals were fired: a South African coal and a Russian Coal under air and oxy-fuel firing conditions. The two coals were also co-fired with Shea Meal at a co-firing mass fraction of 20%. Shea Meal was also co-fired at a mass fraction of 40% and sawdust at 20% with the Russian Coal. An IFRF Aerodynamically Air Staged Burner (AASB) was used. The thermal input was maintained at 0.5 MWt for all conditions studied. The test matrix comprised of varying the Recycle Ratio (RR) between 65% and 75% and furnace exit O{sub 2} was maintained at 3%. Carbon-in-ash samples for burnout determination were also taken. Results show that the highest peak radiative heat flux and highest flame luminosity corresponded to the lowest recycle ratio. The effect of co-firing of biomass resulted in lower radiative heat fluxes for corresponding recycle ratios. Furthermore, the highest levels of radiative heat flux corresponded to the lowest convective heat flux. Results are compared to air firing and the air equivalent radiative and convective heat fluxes are fuel type dependent. Reasons for these differences are discussed in the main text. Burnout improves with biomass co-firing under both air and oxy-fuel firing conditions and burnout is also seen to improve under oxy-fuel firing conditions compared to air. (author)

  1. 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

  2. Effects of calcium magnesium acetate on the combustion of coal-water slurries. Final project report, 1 September 1989--28 February 1993

    SciTech Connect

    Levendis, Y.A.; Wise, D.; Metghalchi, H.; Cumper, J.; Atal, A.; Estrada, K.R.; Murphy, B.; Steciak, J.; Hottel, H.C.; Simons, G.

    1993-07-01

    To conduct studies on the combustion of coal water fuels (CWFs) an appropriate facility was designed and constructed. The main components were (1) a high-temperature isothermal laminar flow furnace that facilitates observation of combustion events in its interior. The design of this system and its characterization are described in Chapter 1. (2) Apparatus for slurry droplet/agglomerate particle generation and introduction in the furnace. These devices are described in Chapters 1 and 3 and other attached publications. (3) An electronic optical pyrometer whose design, construction theory of operation, calibration and performance are presented in Chapter 2. (4) A multitude of other accessories, such as particle fluidization devices, a suction thermometer, a velocimeter, high speed photographic equipment, calibration devices for the pyrometer, etc., are described throughout this report. Results on the combustion of CWF droplets and CWF agglomerates made from micronized coal are described in Chapter 3. In the same chapter the combustion of CWF containing dissolved calcium magnesium acetate (CMA) axe described. The combustion behavior of pre-dried CWF agglomerates of pulverized grain coal is contrasted to that of agglomerates of micronized coal in Chapter 4. In the same chapter the combustion of agglomerates of carbon black and diesel soot is discussed as well. The effect of CMA on the combustion of the above materials is also discussed. Finally, the sulfur capture capability of CMA impregnated micronized and pulverized bituminous coals is examined in Chapter 5.

  3. Preliminary investigation of the effects of coal-water slurry fuels on the combustion in GE coal fueled diesel engine (Task 1. 1. 2. 2. 1, Fuels)

    SciTech Connect

    Not Available

    1990-06-01

    In prior work with the coal fired diesel research engine, a necessity to determine the sensitivity of the engine to a wider range of fuels was resolved and included in the R and D Test Plan submitted on 2/9/89. In general, the economic viability and universal acceptance of the commercial engine will be a factor of its ability to tolerate the widest range of source fuels with minimal fuel beneficiation. As detailed in the R and D Test Plan, a preliminary investigation on the effects of coal-water slurry (CWS) fuels on the combustion in a GE single cylinder test engine was conducted. The following conclusions are obtained from this investigation. All the test CWS fuels were successfully burned in the GE engine combustion system. They include: 3 to 15 microns mean particle size; 0.7 to 2.8% ash level; KY Blue Gem and PA Mariana bituminous coal, WY Kemmer and Spring Creek Sub-Bituminous coal; coal beneficiated with physical and chemical processes; two kinds of additives for OTISCA CWS; and burnout is not effected by ash or particle size within the test range. For each kind of CWS fuel, the detail design parameters of the fuel injection system has to be compatible. With sufficiently high fuel injection pressure, the 3 micron mean particle size OTISCA fuel burns faster than the 5 micron ones. For OTISCA fuel, the burn rate using Ammonium Lignosulfonate as additive is faster than using Ammonium Condensed Naphthalene Sulfonate. Appendices contain data on heat release, fuel characterization reports from two laboratories, general engine test data, and particulate size distribution. 3 refs.

  4. 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.

  5. Leachability of trace elements in coal and coal combustion wastes

    SciTech Connect

    Rice, C.A.; Breit, G.N.; Fishman, N.S.; Bullock, J.H. Jr.

    1999-07-01

    Leaching of trace elements from coal and coal combustion waste (CCW) products from a coal-fired power plant, burning coal from the Appalachian and Illinois basins, was studied using deionized (DI) water as a lixiviant to resemble natural conditions in waste disposal sites exposed to dilute meteoric water infiltration. Samples of bottom ash, fly ash, and feed coal were collected from two combustion units at monthly intervals, along with a bulk sample of wastes deposited in an on-site disposal pond. The units burn different coals, one a high-sulfur coal (2.65 to 3.5 weight percent S) and the other, a low-sulfur coal (0.6--0.9 eight percent S). Short-term batch leaches with DI water were performed for times varying from a few minutes to 18 hours. Select fly ash samples were also placed in long-term (> 1 year) flow-through columns.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Effects of coal combustion and gasification upon lung structure and function. Quarterly progress report, March 12, 1981

    SciTech Connect

    Not Available

    1981-01-01

    The overall objective of the proposed research is to correlate both structural and functional alterations in cells and tissues of the lung brought about by exposure to fluidized bed combustion and fixed bed gasification effluents and reagent grade oxides of metals known to be associated with coal combustion and gasification.

  11. 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...

  12. 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.

  13. ENVIRONMENTAL EFFECTS OF WESTERN COAL COMBUSTION. PART I. THE FISHES OF ROSEBUD CREEK, MONTANA

    EPA Science Inventory

    Fish populations have been studied during 1975 and 1976 in Rosebud Creek, a prairie stream which flows through the Fort Union Coal Basin in southeastern Montana. The objective of this study was to collect fish population data to determine any immediate effects, and to act as a ya...

  14. 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.

  15. 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

  16. Coal combustion: Nuclear resource or danger

    SciTech Connect

    Gabbard, A.

    1993-01-01

    Both the benefits and hazards of coal combustion are more far-reaching than are generally recognized. Technologies exist to remove, store, and generate energy from the radioactive isotopes released to the environment by coal combustion. When considering the nuclear consequences of coal combustion, policymakers should look at the data and recognize that the amount of uranium-235 alone dispersed by coal combustion is the equivalent of dozens of nuclear reactor fuel loadings. They should also recognize that the nuclear fuel potential of the fertile isotopes of thorium-232 and uranium-238, which can be converted in reactors to fissionable elements by breeding, yields a virtually unlimited source of nuclear energy that is frequently overlooked as a natural resource. In short, naturally occurring radioactive species released by coal combustion are accumulating in the environment along with minerals such as mercury, arsenic, silicon, calcium, chlorine, and lead, sodium, as well as metals such as aluminum, iron, lead, magnesium, titanium, boron, chromium, and others that are continually dispersed in millions of tons of coal combustion by-products. The potential benefits and threats of these released materials will someday be of such significance that they should not now be ignored.

  17. 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)

  18. 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...

  19. 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. mphasis is on predicting the size-segregated speciation of trace metals in pulverized-coal-fired power plant effluents. his ...

  20. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1992-04-14

    Research on coal combustion continued. Activities during November 29, 1991 to February 28, 1992 includes: Further analytical results on char array combustion and internal ignition of porous char; preliminary runs using a flat flame burner have been made and a blue flat flame has been obtained; a CID camera, EPIX frame grabber and software, Sony monitor and a 486 Computer to handle image processing frame by frame have been acquired; a new coal feeder has been constructed for feeding through the flat flame burner. Coal experiments have not yet been conducted. Coal samples from Penn State Coal Bank were also acquired for use in the experiments. They include bituminous and subbituminous coals of differing VM.

  1. Char particle fragmentation and its effect on unburned carbon during pulverized coal combustion. Quarterly report, April 1--June 30, 1995

    SciTech Connect

    Mitchell, R.E.

    1996-08-13

    This document is the eleventh quarterly status report of work on a project concerned with the fragmentation of char particles during pulverized coal combustion that was conducted at the High Temperature Gasdynamics Laboratory at Stanford University, Stanford, California. The project is intended to satisfy, in part, PETC`s research efforts to understand the chemical and physical processes that govern coal combustion. The work is pertinent to the char oxidation phase of coal combustion and focuses on how the fragmentation of coal char particles affects overall mass loss rates and how char fragmentation phenomena influence coal conversion efficiency. The knowledge and information obtained allows the development of engineering models that can be used to predict accurately char particle temperatures and total mass loss rates during pulverized coal combustion. In particular, the work provides insight into causes of unburned carbon in the ash of coal-fired utility boilers and furnaces. The overall objectives of the project are: (i) to characterize fragmentation events as a function of combustion environment, (ii) to characterize fragmentation with respect to particle porosity and mineral loadings, (iii) to assess overall mass loss rates with respect to particle fragmentation, and (iv) to quantify the impact of fragmentation on unburned carbon in ash. The knowledge obtained during the course of this project will be used to predict accurately the overall mass loss rates of coals based on the mineral content and porosity of their chars. The work will provide a means of assessing reasons for unburned carbon in the ash of coal fired boilers and furnaces.

  2. 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

  3. 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.

  4. 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.

  5. 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 ...

  6. 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.

  7. 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.

  8. Effects of Steam and CO2 in the Fluidizing Gas when Using Bituminous Coal in Chemical-Looping Combustion

    NASA Astrophysics Data System (ADS)

    Leion, H.; Lyngfelt, A.; Mattisson, T.

    Chemical-looping combustion (CLC) is a combustion technology where an oxygen carrier is used to transfer oxygen from the combustion air to the fuel in order to avoid direct contact between air and fuel. Thus, the CO2 is inherently separated from the flue gases with a potential for considerably lower energy penalty and cost compared to other techniques for CO2 separation. The oxygen carrier is circulated between two reactors, a fuel and an air reactor, where the flue gas from the air reactor contains oxygen depleted air and the flue gas from the fuel reactor contains mainly CO2 and H2O. The water can easily be condensed and the remaining CO2 can be transported for underground storage. Most of the prior work with CLC has focused on using natural gas and syngas as fuel and oxygen carrying material normally produced from pure chemicals. However, recent work on adapting the CLC process for solid fuels with ores and natural minerals as oxygen carrier shows promising results. This paper will present results from reactivity investigations in a laboratory fluidized-bed reactor system using previously investigated natural mineral ilmenite as oxygen carrier and a bituminous Colombian coal as fuel. Experiments were conducted at a temperature of 970°C with N2, steam, and/or CO2 in the fluidizing gas. Synergy effects between steam and CO2 on fuel conversion was noted. The results show that the fuel conversion was a roughly a factor 5 faster with steam as compared to CO2 in the fluidizing gas.

  9. MONITORING STRATEGIES FOR FLUIDIZED BED COMBUSTION COAL PLANTS

    EPA Science Inventory

    Air and water monitoring strategies for commercial-size Fluidized Bed Combustion (FBC) coal plants are presented. This is one of five reports developing air and water monitoring strategies for advanced coal combustion (FBC), coal conversion (coal gasification and liquefaction), a...

  10. 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.)

  11. 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

  12. Differential effect of coal combustion products on the bioavailability of phosphorus between inorganic and organic nutrient sources.

    PubMed

    Seshadri, Balaji; Bolan, Nanthi; Choppala, Girish; Naidu, Ravi

    2013-10-15

    In farming systems, all the applied phosphorus (P) is not available to plants because they are either adsorbed in soil or lost to the environment through leaching or runoff. The effect of coal combustion products (CCPs) for enhancing the bioavailability of applied phosphorus (P) in soil was examined separately for inorganic (KH2PO4 - PP) and organic (poultry manure - PM) P treatments, where fluidised bed combustion (FBC) ash emerged as the most effective amendment. Greenhouse study was conducted by growing mustard plants on FBC amended soils under leaching and non-leaching setups. The FBC increased the biomass yield for organic P treatments in the first crop and increased for both inorganic and organic P in the second cropping. The increase in cumulative yield was highest in leached PP and unleached PM treatments. Field experiment assessed the effectiveness of FBC on inorganic (single super phosphate - SSP) and organic P (biosolids - BS) uptake by mustard and sunflower plants. In the first cropping, the yield was higher in crops treated with SSP alone. In the second crop, yields were higher in the presence than absence of FBC, as reflected by the high relative agronomic effectiveness (RAE) exhibited by BS+FBC (462%) combination. Overall, FBC used in these experiments enhanced bioavailability of P in soil through adsorption and mineralisation of inorganic and organic P, respectively as evident from phosphatase activity and Olsen P relationship. Hence the differential effect of CCPs has not only decreased the loss of applied P (from inorganic and organic sources) to the environment, but also enhanced the P bioavailability in the soil. Among the three CCPs used in the preliminary experiments, FBC proved to perform better than the other two and hence can be recommended for agricultural and environmental applications targeting P issues. PMID:23755844

  13. Electricity from Coal Combustion: Improving the hydrophobicity of oxidized coals

    NASA Astrophysics Data System (ADS)

    Seehra, Mohindar; Singh, Vivek

    2011-03-01

    To reduce pollution and improve efficiency, undesirable mineral impurities in coals are usually removed in coal preparation plants prior to combustion first by crushing and grinding coals followed by gravity separation using surfactant aided water flotation. However certain coals in the US are not amendable to this process because of their poor flotation characteristics resulting in a major loss of an energy resource. This problem has been linked to surface oxidation of mined coals which make these coals hydrophilic. In this project, we are investigating the surface and water flotation properties of the eight Argonne Premium (AP) coals using x-ray diffraction, IR spectroscopy and zeta potential measurements. The role of the surface functional groups, (phenolic -OH and carboxylic -COOH), produced as a result of chemisorptions of O2 on coals in determining their flotation behavior is being explored. The isoelectric point (IEP) in zeta potential measurements of good vs. poor floaters is being examined in order to improved the hydrophobicity of poor floating coals (e.g. Illinois #6). Results from XRD and IR will be presented along with recent findings from zeta potential measurements, and use of additives to improve hydrophobicity. Supported by USDOE/CAST, Contract #DE-FC26-05NT42457.

  14. 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.

  15. HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

    SciTech Connect

    Chris Guenther; Bill Rogers

    2001-09-15

    The HPCCK project was initiated with a kickoff meeting held on June 12, 2001 in Morgantown, WV, which was attended by all project participants. SRI's existing g-RCFR reactor was reconfigured to a SRT-RCFR geometry (Task 1.1). This new design is suitable for performing the NBFZ experiments of Task 1.2. It was decided that the SRT-RCFR apparatus could be modified and used for the HPBO experiments. The purchase, assembly, and testing of required instrumentation and hardware is nearly complete (Task 1.1 and 1.2). Initial samples of PBR coal have been shipped from FWC to SRI (Task 1.1). The ECT device for coal flow measurements used at FWC will not be used in the SRI apparatus and a screw type feeder has been suggested instead (Task 5.1). NEA has completed a upgrade of an existing Fluent simulator for SRI's RCFR to a version that is suitable for interpreting results from tests in the NBFZ configuration (Task 1.3) this upgrade includes finite-rate submodels for devolatilization, secondary volatiles pyrolysis, volatiles combustion, and char oxidation. Plans for an enhanced version of CBK have been discussed and development of this enhanced version has begun (Task 2.5). A developmental framework for implementing pressure and oxygen effects on ash formation in an ash formation model (Task 3.3) has begun.

  16. Effects of coal combustion products and metal compounds on sister chromatid exchange (SCE) in a macrophagelike cell line.

    PubMed

    Andersen, O

    1983-01-01

    Investigations of genotoxic effects of particles have almost exclusively been performed by organic extraction, while direct investigations in cells capable of engulfing particles have only been performed in few cases. Thus, in most studies, the eventual effects of particle-associated metal compounds have remained undiscovered. The present study attempted direct measurement of genotoxic effects of particulate coal combustion products by using the P388D(1) macrophage cell line. The capability of these cells for phagocytosis was demonstrated with insoluble particles. The sister chromatid exchange (SCE) test was used for measuring genotoxic effects of test compounds. Dimethylnitrosamine and benzo(a)pyrene did not increase SCE, indicating that the P388D(1) cell line has lost the capacity for metabolism of latent organic carcinogens, reducing the value of these cells for evaluating genotoxic effects of complex particles. Indirect evidence has been obtained that the cell line may be infected with a virus. Thus, interactions between virus and test compound may lead to erroneous results. This should be kept in mind during evaluation of the results. The effects of metals with reported carcinogenic or mutagenic effects on SCE were compared in P388D(1) cells and human lymphocytes: NaAsO(2), CdCl(2), K(2)Cr(2)O(7), CoCl(2), CH(3)HgCl and MnSO(4) increased SCE in both cell systems. Pb(CH(3)COO)(2), BeSO(4) and NiSO(4) had a weak effect on SCE in P388D(1). Pb(CH(3)COO)(2) and NiSO(4), but not BeSO(4), increased SCE in human lymphocytes. Cr(CH(3)COO)(3) increased SCE in human lymphocytes at high concentration, but was a strong inducer of increased SCE in P388D(1) cells, which take up Cr(III) by phagocytosis. This suggests that the Cr(III) ion is an ultimate carcinogenic form of chromium. Generally P388D(1) cells and human lymphocytes respond to in vitro exposure to metals in agreement with reported mutagenic/carcinogenic effects of the metals. Of four precipitated coal fly ash

  17. Growth and developmental effects of coal combustion residues on Southern Leopard Frog (Rana sphenocephala) tadpoles exposed throughout metamorphosis

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2008-09-15

    The effects of aquatic deposition of coal combustion residues (CCRs) on amphibian life histories have been the focus of many recent studies. In summer 2005, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate (approximately 1 cm deep within plastic bins) and documented effects of sediment type on oral disc condition, as well as time to, mass at, and total body length at key developmental stages, including metamorphosis (Gosner stages (GS) 37, 42, and 46). We found no significant difference in mortality between the two treatments and mortality was relatively low (eight of 48 in the control group and four of 48 in the CCR group). Ninety percent of exposed tadpoles displayed oral disc abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR-contaminated sediment had decreased developmental rates and weighed significantly less at all developmental stages, on average, when compared to controls. The CCR treatment group was also significantly shorter In length than controls at the completion of metamorphosis (GS 46). Collectively, these findings are the most severe sub-lethal effects noted for any amphibian exposed to CCRs to date. More research is needed to understand how these long term effects may contribute to the dynamics of local amphibian populations.

  18. Combustion of Illinois coals and chars with natural gas

    SciTech Connect

    Buckius, R.O.

    1991-01-01

    There are applications where the combined combustion of coal and natural gas offers potential advantages over the use of either coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use during to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary volatiles'' to enhance the combustion. In addition, natural gas provides a clean fuel source of fuel which, in cofiring situations, can extend the usefulness of coals with high sulfur content. The addition of natural gas may reduce SO{sub x} emission through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined coal and natural gas combustion will provide particle ignition, burnout rates and ash characterization, that will help clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms.

  19. Development of Cost Effective Oxy-Combustion Retrofitting for Coal-Fired Boilers

    SciTech Connect

    Hamid Farzan

    2010-12-31

    The overall objective of this project is to further develop the oxy-combustion technology for commercial retrofit in existing wall-fired and Cyclone boilers by 2012. To meet this goal, a research project was conducted that included pilot-scale testing and a full-scale engineering and economic analysis.

  20. COMBUSTION MODIFICATION EFFECTS ON NOX EMISSIONS FROM GAS-, OIL-, AND COAL-FIRED UTILITY BOILERS

    EPA Science Inventory

    The report represents the conclusion of 4 years of analysis of large quantities of emissions, operating conditions, and boiler configuration data from full-scale multiple-burner, electric-generating boilers firing natural gas, oil, and coal fuels. The overall objective of the stu...

  1. 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.

  2. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1996-10-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulate from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDS) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor.

  3. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1997-10-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor. The project was started on July 1, 1994 and this is the thirteenth quarterly technical progress report. Specifically, the following progress has been made during this performance period from July 1, 1997 through September 30, 1997.

  4. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1997-01-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor.

  5. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1997-07-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor.

  6. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1997-04-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Combustion front propagation in underground coal gasification

    SciTech Connect

    Dobbs, R.L. II; Krantz, W.B.

    1990-10-01

    Reverse Combustion (RC) enhances coal seam permeability prior to Underground Coal Gasification. Understanding RC is necessary to improve its reliability and economics. A curved RC front propagation model is developed, then solved by high activation energy asymptotics. It explicitly incorporates extinction (stoichiometric and thermal) and tangential heat transport (THT) (convection and conduction). THT arises from variation in combustion front temperature caused by tangential variation in the oxidant gas flux to the channel surface. Front temperature depends only weakly on THT; front velocity is strongly affected, with heat loss slowing propagation. The front propagation speed displays a maximum with respect to gas flux. Combustion promoters speed front propagation; inhibitors slow front propagation. The propagation model is incorporated into 2-D simulations of RC channel evolution utilizing the boundary element method with cubic hermetian elements to solve the flow from gas injection wells through the coal to the convoluted, temporally evolving, channel surface, and through the channel to a gas production well. RC channel propagation is studied using 17 cm diameter subbituminous horizontally drilled coal cores. Sixteen experiments at pressures between 2000 and 3600 kPa, injected gas oxygen contents between 21% and 75%, and flows between 1 and 4 standard liters per minute are described. Similarity analysis led to scaling-down of large RC ({approx}1 m) to laboratory scale ({approx}5 cm). Propagation velocity shows a strong synergistic increase at high levels of oxygen, pressure, and gas flow. Char combustion is observed, leaving ash-filled, irregularly shaped channels. Cracks are observed to penetrate the char zone surrounding the channel cores. 69 refs., 54 figs., 4 tabs.

  14. Coal combustion: Effect of process conditions on char reactivity. Quarterly technical report, December 1, 1991--March 1, 1992

    SciTech Connect

    Zygourakis, K.

    1992-07-01

    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--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). (VC)

  15. 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).

  16. 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.

  17. 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.

  18. 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.

  19. Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage.

    PubMed

    Kingston, H M Skip; Cain, Randy; Huo, Dengwei; Rahman, G M Mizanur

    2005-09-01

    The chromium species leaching from a coal combustion fly ash landfill has been characterized as well as a novel approach to treat leachates rich in hexavalent chromium, Cr(VI), by using another natural waste by-product, acid mine drainage (AMD), has been investigated during this study. It is observed that as much as 8% (approximately 10 microg g(-1) in fly ash) of total chromium is converted to the Cr(VI) species during oxidative combustion of coal and remains in the resulting ash as a stable species, however, it is significantly mobile in water based leaching. Approximately 1.23 +/- 0.01 microg g(-1) of Cr(VI) was found in the landfill leachate from permanent deposits of aged fly ash. This study also confirmed the use of AMD, which often is in close proximity to coal combustion by-product landfills, is an extremely effective and economical remediation option for the elimination of hexavalent chromium in fly ash generated leachate. Speciated isotope dilution mass spectrometry (SIDMS), as described in EPA Method 6800, was used to analytically evaluate and validate the field application of the ferrous iron and chromate chemistry in the remediation of Cr(VI) runoff. PMID:16121270

  20. 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.

  1. Mercury emissions from coal combustion in China

    SciTech Connect

    David G. Streets; Jiming Hao; Shuxiao Wang; Ye Wu

    2009-07-01

    This chapter reviews the magnitude and spatial distribution of mercury emissions from coal combustion in China. Due to the large quantities of coal burned and the relatively low level of technology, particularly in industry, emissions are high. Emissions were stable at about 200-210 Mg during the period 1995-2000, but because of rapid economic growth starting in 2001, mercury emissions grew quickly to a value of 334 Mg in 2005. The annual average growth rate for the period 1995-2005 was 5.1%. The uncertainty in emission estimates is about {+-}35% (95% confidence intervals). Emissions are concentrated in those provinces with high concentrations of mercury in coal (like Guizhou Province) and provinces in which a lot of coal is burned (like Shanxi Province). Because significant amounts of coal are burned in homes and small industrial facilities, without any kind of emission control at all, emissions of particulate mercury are higher in China than in the developed world; the speciation profile nationwide is: 64% Hg{sup II}, 19% Hg{sup p}, and 17% Hg{sup 0}. In the future, growth in mercury emissions is expected to be limited by the application of FGD for SO{sub 2} control and other advanced technologies. Estimates of emissions are hampered by the lack of comprehensive and reliable emissions testing programs in China.

  2. APPLICATION OF ADVANCED TECHNOLOGY FOR NOX CONTROL: ALTERNATE FUELS AND FLUIDIZED-BED COAL COMBUSTION

    EPA Science Inventory

    The paper discusses the effect of alternate fuels and fluidized coal combustion in controlling the emission of nitrogen oxides (NOx). The current trend in energy use in the U.S. is toward greater use of coal and coal derived fuels, and on ensuring that these fuels are produced an...

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Coal combustion: Effect of process conditions on char reactivity. Quarterly technical report No. 14, January 1, 1995--March 31, 1995

    SciTech Connect

    Zygourakis, K.

    1995-09-01

    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; (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 No. 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. 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.

  9. MERCURY CAPTURE ON COAL COMBUSTION FLY ASH. (R827649)

    EPA Science Inventory

    A study was performed at the Energy and Environmental Research Center (EERC) to test the hypotheses that (1) different carbon types contained in coal combustion fly ash have variable sorption capabilities relative to mercury and (2) the inorganic fraction of coal combustion fl...

  10. 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.

  11. Char particle fragmentation and its effects on unburned carbon during pulverized coal combustion. Quarterly report, January 1, 1995--March 31, 1995

    SciTech Connect

    Mitchell, R.E.

    1995-08-01

    This document is the tenth quarterly status report of work on a project concerned with the fragmentation of char particles during pulverized coal combustion that is being conducted at the High Temperature Gasdynamics Laboratory at Stanford University. The project is intended to satisfy, in part, PETC`s research efforts to understand the chemical and physical processes that govern coal combustion. The work is pertinent to the char oxidation phase of coal combustion and focuses on how the fragmentation of coal char particles affects overall mass loss rates and how char fragmentation phenomena influence coal conversion efficiency. The knowledge and information obtained will allow the development of engineering models that can be used to predict accurately char particle temperatures and total mass loss rates during pulverized coal combustion. The overall objectives of the project are: (1) to characterize fragmentation events as a function of combustion environment, (2) to characterize fragmentation with respect to particle porosity and mineral loadings, (3) to assess overall mass loss rates with respect to particle fragmentation, and (4) to quantify the impact of fragmentation on unburned carbon in ash. The knowledge obtained during the course of this project will be used to predict accurately the overall mass loss rates of coals based on the mineral content and porosity of their chars. The work will provide a means of assessing reasons for unburned carbon in the ash of coal fired boilers and furnaces. Accomplishments for this period are presented for Task 3, char fragmentation studies and Task 4, fragmentation modelling.

  12. 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.

  13. Combustion behavior of low rank coal water slurries

    SciTech Connect

    Yavuz, R.; Kuecuekbayrak, S.; Williams, A.

    1996-12-31

    Coal water slurries have been developed over the last 15 years as an alternative to fuel oil mainly in industry and power station boilers. Observing of droplet lifetime reveals details of the mechanism of the slurry combustion. In the present investigation, single droplet combustion of lignite water slurries using different Turkish lignites were experimentally studied by using single droplet combustion technique. The technique is based on thermometric method. Results of combustion behavior of low rank coal water slurries were compared with that of high rank coal water slurries which were found in the literature.

  14. 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

    focused on the behavior of trace metals in the combustion zone by studying vaporization from single coal particles. The coals were burned at 1700 K under a series of fuel-rich and oxygen-rich conditions. The data collected in this study will be applied to a model that accounts for the full equilibrium between carbon monoxide and carbon dioxide. The model also considers many other reactions taking place in the combustion zone, and involves the diffusion of gases into the particle and combustion products away from the particle. A comprehensive study has been conducted at UA to investigate the post-combustion partitioning of trace elements during large-scale combustion of pulverized coal combustion. For many coals, there are three distinct particle regions developed by three separate mechanisms: (1) a submicron fume, (2) a micron-sized fragmentation region, and (3) a bulk (>3 {micro}m) fly ash region. The controlling partitioning mechanisms for trace elements may be different in each of the three particle regions. A substantial majority of semi-volatile trace elements (e.g., As, Se, Sb, Cd, Zn, Pb) volatilize during combustion. The most common partitioning mechanism for semi-volatile elements is reaction with active fly ash surface sites. Experiments conducted under this program at UC focused on measuring mercury oxidation under cooling rates representative of the convective section of a coal-fired boiler to determine the extent of homogeneous mercury oxidation under these conditions. In fixed bed studies at EERC, five different test series were planned to evaluate the effects of temperature, mercury concentration, mercury species, stoichiometric ratio of combustion air, and ash source. Ash samples generated at UA and collected from full-scale power plants were evaluated. Extensive work was carried out at UK during this program to develop new methods for identification of mercury species in fly ash and sorbents. We demonstrated the usefulness of XAFS spectroscopy for the

  15. Health effects of air pollution due to coal combustion in the Chestnut Ridge region of Pennsylvania

    SciTech Connect

    Batterman, S.; Golomb, D.

    1985-08-01

    This study used the seventeen monitor air quality network in the Chestnut Ridge region of Pennsylvania to evaluate the effect of pollutant trends and representations on measures of exposure. Data consisted of four and five years of SO/sub 2/ and TSP measurements, respectively, and were considered in deriving exposure models. A cross-sectional study of 4071 children aged 6 to 11 years of age was conducted in the spring of 1979. Standardized children's questionnaires were distributed to the parents and returned by the children to school, where spirometry was performed. The region was divided into low, moderate and high pollution areas on the basis of the 1974-1978, 3 h, 24 h, and annual averages for SO/sub 2/. After adjusting the respiratory symptom response outcomes and the pulmonary function levels for known predictors, no significant association was noted for level of SO/sub 2/. 65 refs., 16 figs., 19 tabs.

  16. Effect of coal combustion fly ash use in concrete on the mass transport release of constituents of potential concern.

    PubMed

    Garrabrants, Andrew C; Kosson, David S; DeLapp, Rossane; van der Sloot, Hans A

    2014-05-01

    Concerns about the environmental safety of coal combustion fly ash use as a supplemental cementitious material have necessitated comprehensive evaluation of the potential for leaching concrete materials containing fly ash used as a cement replacement. Using concrete formulations representative of US residential and commercial applications, test monoliths were made without fly ash replacement (i.e., controls) and with 20% or 45% of the portland cement fraction replaced by fly ash from four coal combustion sources. In addition, microconcrete materials were created with 45% fly ash replacement based on the commercial concrete formulation but with no coarse aggregate and an increased fine aggregate fraction to maintain aggregate-paste interfacial area. All materials were cured for 3 months prior to mass transport-based leach testing of constituents of potential concern (i.e., Sb, As, B, Ba, Cd, Cr, Mo, Pb, Se, Tl and V) according to EPA Method 1315. The cumulative release results were consistent with previously tested samples of concretes and mortars from international sources. Of the 11 constituents tested, only Sb, Ba, B, Cr and V were measured in quantifiable amounts. Microconcretes without coarse aggregate were determined to be conservative surrogates for concrete in leaching assessment since cumulative release from microconcretes were only slightly greater than the associated concrete materials. Relative to control materials without fly ash, concretes and microconcretes with fly ash replacement of cement had increased 28-d and 63-d cumulative release for a limited number 10 comparison cases: 2 cases for Sb, 7 cases for Ba and 1 case for Cr. The overall results suggest minimal leaching impact from fly ash use as a replacement for up to 45% of the cement fraction in typical US concrete formulations; however, scenario-specific assessment based on this leaching evaluation should be used to determine if potential environmental impacts exist. PMID:24359922

  17. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYSTEMS

    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...

  18. 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...

  19. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 17, April--June 1993

    SciTech Connect

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

    1993-08-01

    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 1993, the following technical progress was made: Completed modeling calculations of coal mineral matter transformations, deposition behavior, and heat transfer impacts of six test fuels; and ran pilot-scale tests of Upper Freeport feed coal, microagglomerate product, and mulled product.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. USGS TOXIC SUBSTANCES FROM COAL COMBUSTION -- FORMS OF OCCURRENCE ANALYSIS

    SciTech Connect

    Allan Kolker; Stanley J. Mroczkowski; Curtis A. Palmer; Robert B. Finkelman

    1999-04-01

    Detailed information on trace-element modes of occurrence in coal is essential to understanding and predicting trace-element transformations taking place during coal combustion. The USGS has developed quantitative and semi-quantitative methods for determining the mode of occurrence of trace elements in coal. This information is needed to generate predictive models for trace-element behavior, the ultimate goal of DOE contract DE-AC22-95PC95101 ``Toxic Substances From Coal Combustion--A Comprehensive Assessment'' awarded to PSI, Inc. USGS activities in support of this contract have a direct bearing on the predictive equations being developed as the primary product of the PSI program.

  6. Effects of calcium magnesium acetate on the combustion of coal-water slurries. Twelfth quarterly project status report, 1 June 1992--31 August 1992

    SciTech Connect

    Levendis, Y.A.

    1992-12-01

    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 studied. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion. To help achieve these objectives the following project tasks were carried over this 11th three-month period. Work on three major tasks was conducted over this period: (a) We obtained a larger inventory of pyrometric and cinematographic observations on single CWF particles of micronized coal, with and without CMA, burning in various O{sub 2} Partial pressures and wall temperatures. (b) Preliminary reaction rate calculations were completed using simplified models. (c) Work has been started on optimizing and running a computer program that performs detailed calculation of reaction rates. (d) Development work on the new single drop generator has continued. (e) A new laboratory space has been prepared and assigned to this project.

  7. 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.

  8. CONTROL OF TRACE METAL EMISSIONS DURING COAL COMBUSTION

    SciTech Connect

    THOMAS C. HO

    1998-02-18

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor. This final technical report details the work performed, the conclusions obtained, and the accomplishments achieved over the project performance period from July 1, 1994 through December 31, 1997. Specifically, this report consists of the following five chapters: Chapter 1. Executive Summary; Chapter 2. Metal Capture by Various Sorbents; Chapter 3. Simultaneous Metal and Sulfur Capture; Chapter 4. Sorption and Desorption of Mercury on Sorbents; and Chapter 5. Project Conclusions. In summary, the metals involved in the project were arsenic, cadmium, chromium, lead, mercury and selenium and the sorbents tested included bauxite, zeolite and calcined limestone. The three sorbents have been found to have various degree of metal capture capability on arsenic, cadmium, chromium and lead

  9. 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.

  10. 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.

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

    SciTech Connect

    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.

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. Evaluation of the behavior of Colombian coals during the combustion in fixed bed

    SciTech Connect

    Giraldo, M.; Chejne, F.; Hill, A.

    2000-07-01

    The improvements in the technological processes that have coal as energy source must be based on the knowledge of physical and chemical properties of coal and in the knowledge of its evolution during the combustion process. These characteristics are involved in the coal behavior. Moreover, the coal porosity has an important relevance on the reaction rate and in diverse physical and chemical properties, and therefore, is a key parameter in the usefulness of coal. This project includes studies about Colombian coal combustion and its kinetic behavior. The coal was characterized and classified by particle size,and origin. In this research project, the physical and chemical properties of coal that affect its applicability in different kinds of technological processes have been studied as well as the characteristics that could be related to pollutant generation. The study considers the following issues: the types and level of criteria pollutant precursor compounds such as sulfur and nitrogen in coal, the influence of particle size and porosity in the generation of pollutant species, the participation of pollutant species in the combustion process, and basic properties such as heat capacity, and heat effects related to the conversion of coal during heating test. Coal from Antioquia, Valle del Cauca and Cundinamarca Regions were used. These coals are used domestically by the industrial and power sector. Particle sizes of 4, 2.5 and 1 cm were used from each one of these coals. The combustion tests were done in a fixed bed pilot furnace. The amount of air used was controlled during the experiment. In addition, air and gas flow, concentration and temperatures were registered. This paper presents a description of: characteristics of each test, composition of generated gases, and the influence of the particle size and coal origin in the pollutant emissions, also includes the results of test done in different samples took along each test.

  17. 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.

  18. Analysis of cyclic combustion of the coal-water suspension

    NASA Astrophysics Data System (ADS)

    Kijo-Kleczkowska, Agnieszka

    2011-04-01

    Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.

  19. 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.

  20. AIR EMISSIONS FROM COMBUSTION OF SOLVENT REFINED COAL

    EPA Science Inventory

    The report gives details of a Solvent Refined Coal (SRC) combustion test at Georgia Power Company's Plant Mitchell, March, May, and June 1977. Flue gas samples were collected for modified EPA Level 1 analysis; analytical results are reported. Air emissions from the combustion of ...

  1. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 12, January--March 1992

    SciTech Connect

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

    1992-08-01

    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. 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; completed editing of the fifth quarterly report and sent it to the publishing office; and prepared two technical papers for conferences.

  2. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 14, July--September 1992

    SciTech Connect

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

    1993-02-01

    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; published two technical papers at conferences; and prepared for upcoming tests of new BCFs being produced.

  3. ANALYSIS FOR RADIONUCLIDES IN SRC AND COAL COMBUSTION SAMPLES

    EPA Science Inventory

    The report deals with the determination of the levels of uranium, thorium, and their daughter products in coal, SRC, coal flyash, and SRC flyash samples taken from Georgia Power Company's Plant Mitchell during the May and June 1977 combustion tests to compare the environmental em...

  4. Char particle fragmentation and its effect on unburned carbon during pulverized coal combustion. Quarterly report, July 1, 1995--September 30, 1995

    SciTech Connect

    Mitchell, R.E.

    1996-09-13

    This project is intended to satisfy, in part, PETC`s research efforts to understand the chemical and physical processes that govern coal combustion. The work is pertinent to the char oxidation phase of coal combustion and focuses on how the fragmentation of coal char particles affects overall mass loss rates and how char fragmentation phenomena influence coal conversion efficiency. The knowledge and information obtained allows the development of engineering models that can be used to predict accurately char particle temperatures and total mass loss rates during pulverized coal combustion. In particular, the work provides insight into causes of unburned carbon in the ash of coal-fired utility boilers and furnaces. The information reported is for the period July I to September 30, 1995, although the actual work was performed over an extended period of time, from July 1, 1995 to August 1996. During this period, activities were undertaken in Task 3, char fragmentation studies, and Task 4, fragmentation modeling. Partially reacted chars were extracted from the laminar flow reactor at selected residence times and analyzed to determine extents of mass loss and particle size distributions and the particle population balance model was modified to take into account density variations for each size class of particles considered in the model.

  5. 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.

  6. 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.

  7. 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.

  8. Ignition and devolatilization of pulverized bituminous coal particles during oxygen/carbon dioxide coal combustion

    SciTech Connect

    Alejandro Molina; Christopher R. Shaddix

    2007-07-01

    Oxygen/carbon dioxide recycle coal combustion is actively being investigated because of its potential to facilitate CO{sub 2} sequestration and to achieve emission reductions. In the work reported here, the effect of enhanced oxygen levels and CO{sub 2} bath gas is independently analyzed for their influence on single-particle pulverized coal ignition of a U.S. eastern bituminous coal. The experiments show that the presence of CO{sub 2} and a lower O{sub 2} concentration increase the ignition delay time but have no measurable effect on the time required to complete volatile combustion, once initiated. For the ignition process observed in the experiments, the CO{sub 2} results are explained by its higher molar specific heat and the O{sub 2} results are explained by the effect of O{sub 2} concentration on the local mixture reactivity. Particle ignition and devolatilization properties in a mixture of 30% O{sub 2} in CO{sub 2} are very similar to those in air. 23 refs., 8 figs., 1 tab.

  9. Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production – A pot experiment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Byproducts of coal combustion (such as fly ash: FA), livestock industry (such as chicken manure: CM, or animal manure, etc), or water treatment residuals (such as sewage sludge: SS, or incinerated sewage sludge: ISS) can be used as amendments to agricultural soils, provided that these byproducts (ap...

  10. Fiber optic sensing system for temperature and gas monitoring in coal waste pile combustion environments

    NASA Astrophysics Data System (ADS)

    Viveiros, D.; Ribeiro, J.; Ferreira, J.; Lopez-Albada, A.; Pinto, A. M. R.; Perez-Herrera, R. A.; Diaz, S.; Lopez-Gil, A.; Dominguez-Lopez, A.; Esteban, O.; Martin-Lopez, S.; Auguste, J.-L.; Jamier, R.; Rougier, S.; Silva, S. O.; Frazão, O.; Santos, J. L.; Flores, D.; Roy, P.; Gonzalez-Herraez, M.; Lopez-Amo, M.; Baptista, J. M.

    2015-09-01

    It is presented an optical fiber sensing system projected to operate in the demanding conditions associated with coal waste piles in combustion. Distributed temperature measurement and spot gas sensing are requirements for such a system. A field prototype has been installed and is continuously gathering data, which will input a geological model of the coal waste piles in combustion aiming to understand their dynamics and evolution. Results are presented on distributed temperature and ammonia measurement, being noticed any significant methane emission in the short time period considered. Carbon dioxide is also a targeted gas for measurement, with validated results available soon. The assessment of this technology as an effective and reliable tool to address the problem of monitoring coal waste piles in combustion opens the possibility of its widespread application in view of the worldwide presence of coal related fires.

  11. Health effects of coal technologies: research needs

    SciTech Connect

    Not Available

    1980-09-01

    In this 1977 Environmental Message, President Carter directed the establishment of a joint program to identify the health and environmental problems associated with advanced energy technologies and to review the adequacy of present research programs. In response to the President's directive, representatives of three agencies formed the Federal Interagency Committee on the Health and Environmental Effects of Energy Technologies. This report was prepared by the Health Effects Working Group on Coal Technologies for the Committee. In this report, the major health-related problems associated with conventional coal mining, storage, transportation, and combustion, and with chemical coal cleaning, in situ gasification, fluidized bed combustion, magnetohydrodynamic combustion, cocombustion of coal-oil mixtures, and cocombustion of coal with municipal solid waste are identified. The report also contains recommended research required to address the identified problems.

  12. 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.

  13. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Beal, H.R.; Gralton, G.W.; Gronauer, T.W.; Liljedahl, G.N.; Love, B.F.

    1987-06-01

    Activities conducted under this contract include studies on the combustion and fireside behavior of numerous coal-water fuels (CWFs). The work has been broken down into the following areas: Task 1 -- Selection of Candidate Fuels; Task 2 -- Bench Scale Tests; Task 3 -- CWF Preparation and Supply; Task 4 -- Combustion Characterization; Task 5 -- Ash Deposition and Performance Testing; Task 6 -- Commercial Applications. This report covers Task 6, the study of commercial applications of CWFs as related to the technical and economic aspects of the conversion of existing boilers and heaters to CWF firing. This work involves the analysis of seven units of various sizes and configurations firing several selected CWFs. Three utility boilers, two industrial boilers, and two process heater designs are included. Each of the units was considered with four primary selected CWFs. A fifth fuel was considered for one of the utility units. A sixth fuel, a microfine grind CWF, was evaluated on two utility units and one industrial unit. The particular fuels were chosen with the objective of examining the effects of coal source, ash level, ash properties, and beneficiation on the CWF performance and economics of the seven units. 10 refs., 81 figs., 80 tabs.

  14. Treatment of chromic tannery wastes using coal ashes from fluidized bed combustion of coal

    SciTech Connect

    Bulewicz, E.M.; Kozak, A.; Kowalski, Z.

    1997-10-01

    A new method of treatment for chromic tannery wastes containing chrome and large amounts organic substances has been investigated. It has been found that the addition of certain types of coal ash from fluid bed combustion technologies, at a suitable temperature and pH, results in effective removal of Cr(III) compounds present in the wastes. The wastes could then be subjected to further processing in conventional biological treatment units. The method is very simple, cheap, and effective and could be used for chromic tannery wastes of different compositions.

  15. 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.

  16. Combustion of black coal in the form of coal-water slurry in low-capacity boilers

    NASA Astrophysics Data System (ADS)

    Maltsev, L. I.; Kravchenko, I. V.; Lazarev, S. I.; Lapin, D. A.

    2014-07-01

    The present paper describes the examples of experimental and industrial implementation of technologies of flame-droplet combustion of the coal-water mixture in furnaces above a bed consisting of burning coal and in a swirling-type furnace chamber. For preparing coal-water fuel (CWF), Kuznetsk coals of G and D ranks, as well as tailings of coking coals, were used. The future prospect of both technologies of coal combustion has been shown from both economic and environmental standpoints.

  17. 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., Jr.; 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).

  18. 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.

  19. 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. PMID:26259722

  20. 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.

  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. 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.

  3. 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

  4. 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.

  5. 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.

  6. Elution of Ti during solvent extraction of coal and the transformation of eluted Ti upon combustion

    SciTech Connect

    Zhang, L.A.; Takanohashi, T.; Saito, I.; Wang, Q.Y.; Ninomiya, Y.

    2008-06-15

    Solvent extraction of coal is an effective method for removing coal ash, thereby generating the ultraclean fuel that can be directly combusted in gas turbine. Due to their organic affinity, a few inorganic elements can be extracted as well. Ti in coal extract, its elution from raw coal as well as the transformation of eluted Ti during coal extract combustion, have been investigated. Two coals of the U.S. and their acid-washed samples were extracted under 1 MPa N{sub 2} (cold) at 360{sup o}C. The solvents used include nonpolar 1-methylnaphthalene and its mixtures with polar indole. The results indicate that, Ti in coal extracts is mainly composed of nanoparticles including TiO{sub 2} (anatase) and Ti associated with quartz. These particles are insoluble in any acids, having a fine dispersion into coal matrix. Upon coal fragmentation at 360{sup o}C, they could be liberated, and, hence, traversed the filter for isolating coal extracts. The organo-Ti was preferentially extracted as well, which is most likely in a form of Ti porphyrin or Ti chelated with phenol-oxygen. These findings also have implications for revealing the modes of occurrence of Ti in the raw coals. Combustion of coal extract at 1,000{sup o}C resulted in the formation of nanometric TiO{sub 2} polymorphs and complex compounds like FeZnTiO{sub 4}. The former species could be mainly formed by the phase change of TiO{sub 2} (anatase) at high-temperatures, while formation of the latter one could involve the capture of metallic vapors like Zn on TiO{sub 2} polymorphs.

  7. Coal combustion products 2007 production and use report

    SciTech Connect

    2009-07-01

    The American Coal Ash Association's 2007 Annual Coal Combustion Products (CCP) are derived from data from more than 170 power plants. The amount of CCPs used was 40.55%, a decrease of 2.88% from 2006, attributed to reduced fuel burn and a decrease in demand in the building industry. Figures are given for the production of fly ash, flue gas desulfurization gypsum, bottom ash, FBC ash and boiler slag. The article summarises results of the survey. 1 ref., 1 tab.

  8. Combustion characterization of the blend of plant coal and recovered coal fines

    SciTech Connect

    Singh, Shyam.

    1991-01-01

    The overall objective of this proposed research program is 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 will be prepared and utilized. The blend samples will be of a mixture of 90% plant coal + 10% fines, 85% plant coal + 15% fines, 80% plant coal + 20% fines having particle size distribution of 70% passing through {minus}200 mesh size. 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 will be used mainly to measure the emissions and ash deposition study, while the drop tube furnace will be used to determine burning profile, combustion efficiency, etc. This report covers the first quarter's progress. Major activities during this period were focused on finding the plants where a demo MTU column will be installed to prepare the samples needed to characterize the combustion behavior of slurry effluents. Also, a meeting was held at Penn State University to discuss the availability of the laboratory furnace for testing the plant coal/recovered coal fines blends.

  9. A low emission technology -- low cost coal water mixture fired fluidized bed combustion

    SciTech Connect

    Jianhua Yan; Xuguang Jiang; Yong Chi

    1995-12-31

    In this paper, low cost coal water mixture (CWM) FBC technology is described. Low cost CWM may be coal washery sludge or the mixture of water and coal crashed easily. This technology is featured by agglomerate combustion of low cost MM. Experimental results in 0.5MW FBC test rig are reported. lie effects of bed temperate excess air, staged combustion on combustion and emission performance has been studied. The comparison combustion tests by using dry coal and CWM we made ha 0.5MW FBC test rig. Also coal washery sludge of different origins are also tested in the test rig. Based on the test rig comments a demonstration AFBC boiler with capacity of 35 T/H steam for utility application (6 MW) is designed. The design features will be presented in this paper Both the operation experience of test rig and demonstration unit show the developed low cost CWM FBC technology is of high combustion efficiency and low emission. This technology is being commercialized and applied in China in top priority by Chinese government.

  10. 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.

  11. FATE OF COAL NITROGEN DURING COMBUSTION

    EPA Science Inventory

    The paper describes the burning of 21 coals, covering all ranks and under a wide variety of conditions, to ascertain the impact of coal properties on the fate of fuel nitrogen. Fuel NC was identified by using a nitrogen-free oxidant consisting of Ar/O2/CO2. It was found that fuel...

  12. 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...

  13. 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

  14. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 16, January--March 1993

    SciTech Connect

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

    1993-05-01

    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 first quarter of 1993, the following technical progress was made: Reported results of drop tube furnace data analyses to determine devolatilization kinetics; reported the results from the re-analyzed pilot-scale ash deposits from the first nine feed coals and BCFs using a modified CCSEM technique; and prepared for upcoming tests of new BCFs being produced.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 13, April--June 1992

    SciTech Connect

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

    1992-09-01

    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; completed analyses of the samples from the pilot-scale ash deposition tests of unweathered Upper Freeport feed coal; published two technical papers at conferences; and prepared for upcoming tests of new BCFs being produced.

  16. 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.

  17. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  18. 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

  19. Dynamic effects of combustion

    NASA Technical Reports Server (NTRS)

    Oppenheim, A. K.

    1982-01-01

    The dynamic effects of combustion are due to the evolution of exothermic energy and its deposition in the compressible medium where the process takes place. The paper examines the dynamics of combustion phenomena, including ignition, turbulent flame propagation (inflammation), explosion, and detonation, with emphasis on their exothermic characteristics. Ignition and explosion are treated as problems of nonlinear mechanics, and their dynamic behavior is described in terms of phase space models and cinematographic laser shear interferograms. The results of a numerical random vortex model of turbulent flame propagation are confirmed in a combustion tunnel experiment, where it was observed that a fresh mixture of burnt and unburnt gases can sustain combustion with a relatively small expenditure of overall mass flow, due to the increasing specific volume of burnt gases inside the flame front. An isentropic pressure wave is found to precede the accelerating flame in the process of detonation, and components of this presssure wave are shown to propagate at local sonic velocities.

  20. 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.

  1. Removal of mercury from coal-combustion flue gas

    SciTech Connect

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

    1995-12-31

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Combustion of coal/water mixtures with thermal preconditioning

    SciTech Connect

    Novack, M.; Roffe, G.; Miller, G.

    1987-07-01

    Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolatilize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 lb/hr and combustor pressure of 8 atm. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 340/sup 0/F to 600/sup 0/F, and combustion air was supplied at between 600/sup 0/F to 725/sup 0/F. Test durations varied between 10 and 20 min. Major results of the combustion testing were that: A stable flame was maintained over a wide equivalence ratio range, between phi = 2.2 (rich) and 0.2 (lean); and combustion efficiency of over 99 percent was achieved when the mixture was preconditioned to 600/sup 0/F and the combustion air preheated to 725/sup 0/F. Measurements of ash particulates, captured in the exhaust sampling probe located 20 in. from the injector face, show typical sizes collected to be about 1 ..mu..m, with agglomerates of these particulates to be not more than 8 ..mu..m. The original mean coal particle size for these tests, prior to preconditioning, was 25 ..mu..m. Results of additional tests showed that one third of the sulfur contained in the solids of a coal/water mixture with 3 percent sulfur was evolved in gaseous form (under mild thermolized conditions) mainly as H/sub 2/S with the remainder as light mercaptans.

  8. Spontaneous combustion prediction of coal by C80 and ARC techniques

    SciTech Connect

    Qingsong Wang; Song Guo; Jinhua Sun

    2009-09-15

    Many coal fires were caused by spontaneous combustion in coal mines or coal storehouses, which resulted in a great loss and energy wastage. To identify and evaluate the hazardous degree of coal stockpile, a C80 microcalorimeter and accelerating rate calorimeter (ARC) were employed in this work. The coal samples undergo an exothermal process start at 80 {sup o}C with heat generation of -75.1 J g{sup -1} (mean value) detected by C80 experiment. The activation energies of the first exothermal process were calculated for the three experiments, and the mean value is 80.76 kJ mol{sup -1}, which is lower than that of obtained from the ARC result, 127.0 kJ mol{sup -1}. For a 300 tons coal stockpile, the self-heating oxidation temperatures (SHOT) were calculated as 164, 60, 90, and 68{sup o}C based on the ARC experiment and three C80 experiments, respectively. Further research on the mass effect on SHOT shows that if the coal mass is less than 12 tons, the danger of thermal spontaneous combustion is less. However, if the mass amount is more than 12000 tons, the danger of thermal spontaneous combustion is difficult to avoid even at ambient temperature if no special measures are taken. 38 refs., 9 figs.

  9. Combustion of coal in an opposed gas-particle jet with regenerative pyrolysis. Final report

    SciTech Connect

    Durbetaki, P.

    1980-08-31

    The burning of coal particles is the coupled effect of the interlinked processes of pyrolysis, ignition and combustion of the volatiles and char. The specific objectives for the current research program are: (i) to establish an operating system with regenerative pyrolysis, (ii) to identify the primary parameters which effect the pyrolysis, ignition and combustion of the particles in this system, (iii) to identify measurements which are needed and techniques to be developed for these measurements, and (iv) to establish a preliminary basis for a modeling analysis. The present studies carried out with the flat flame burner and the opposed gas-particle jet have shown the feasibility of studying the ignition of pyrolyzate and coal particles. These were found to be affected by the level of preheating, composition of carrier gas and type of fuel particle. The behavior of lignite particles compared to bituminous particles were found to be distinctly different. Pyrolysis experiments carried out on the two coals at heating rates near those experienced with regenerative pyrolysis, have shown that self-ignition temperatures of fuel lean mixtures are not effected by the variable considered in this investigation. Sooting was found to accompany the combustion of bituminous coal particles and not of the lignite particles. Also higher gas-particle rates were found to be needed to self-sustain the combustion of bituminous coal particles than those required for lignite coal particles. These preliminary studies in the three areas of ignition, pyrolysis and combustion have shown the need to use additional instrumentation to further quantify the behavior of these coal particles under regenerative pyrolysis conditions.

  10. 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.

  11. EVALUATION OF THE IMPACT OF CHLORINE ON MERCURY OXIDATION IN A PILOT-SCALE COAL COMBUSTION--THE EFFECT OF COAL BLENDING

    EPA Science Inventory

    Coal-fired power plants are a major source of mercury (Hg) released into the environment and the utility industry is currently investigating options to reduce Hg emissions. The EPA Clean Air Mercury Rule (CAMR) depends heavily on the co-benefit of mercury removal by existing and ...

  12. 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). nderstanding the conversion of fuel nitrogen to nitro...

  13. 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...

  14. 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

  15. 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.

  16. Effects of the furnace temperature on the CO, CO{sub 2}, NO{sub x} and unburned hydrocarbon emissions from the combustion of coal and alternative fuels

    SciTech Connect

    Levendis, Y.A.; Atal, A.; Courtemanche, B.

    1999-07-01

    Results are presented on the emissions of carbon monoxide (CO), carbon dioxide (CO{sub 2}), unburned aromatic hydrocarbons, as well as oxides of nitrogen (NO{sub x}) from the combustion of pulverized bituminous coal, tire-derived fuel and, for a limited number of runs, waste plastics-derived fuel. The particle size cuts of pulverized coal, tire and plastics were 63--75 {micro}m and 180--300 {micro}m, respectively. Combustion experiments were conducted in a laboratory-scale drop-tube furnace at gas temperatures, in the range of 1,300--1,600 K, and several fuel mass loadings in the furnace, expressed in terms of global equivalence ratios in the range of 0.4--2.4. The CO, CO{sub 2} and NO{sub x} emissions were monitored continuously with infrared absorption and chemiluminescent instruments. Up to sixty 2-7 ring polynuclear aromatic hydrocarbons (PAH) were detected by capillary gas chromatography - mass spectrometry (GC-MS) techniques. Results showed that the PAH emission yields (mg/g fuel introduced) increased drastically with increasing bulk equivalence ratio (in the aforementioned range), at fixed furnace temperatures. This was also true for the CO yields, while the CO{sub 2} yields increased with increasing {o}, reached a maximum around stoichiometry and then decreased mildly. NO{sub x} yields decreased precipitously with increasing equivalence ratio. The CO and, especially, the PAH yields from tire-derived and plastics-derived fuels were much higher than those from coal, but the relative amounts of individual PAH components were remarkably similar in the combustion effluent of all fuels. The CO{sub 2} emissions and, especially, the NO{sub x} emissions from tire crumb were lower than those from coal. The CO{sub 2} emissions from plastics were comparable to those from coal, but their NO {sub x} emissions were much lower than those from tire. At fixed bulk equivalence ratios, however, as the furnace gas temperature increased the PAH yields from coal, tire crumb, and

  17. 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.

  18. Electricity from coal and utilization of coal combustion by-products

    SciTech Connect

    Demirbas, A.

    2008-07-01

    Most electricity in the world is conventionally generated using coal, oil, natural gas, nuclear energy, or hydropower. Due to environmental concerns, there is a growing interest in alternative energy sources for heat and electricity production. The major by-products obtained from coal combustion are fly ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) materials. The solid wastes produced in coal-fired power plants create problems for both power-generating industries and environmentalists. The coal fly ash and bottom ash samples may be used as cementitious materials.

  19. 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

    Laboratory measurements of mercury oxidation during selective catalytic reduction (SCR) of nitric oxide, simulation of pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash, and synthesis of new materials for simultaneous oxidation and adsorption of mercury, were performed in support of the development of technology for control of mercury emissions from coal-fired boilers and furnaces. Conversion of gas-phase mercury from the elemental state to water-soluble oxidized form (HgCl{sub 2}) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} SCR catalyst with increasing HCl at low levels of HCl (< 10 ppmv) and decrease in mercury oxidation with increasing NH{sub 3}/NO ratio during SCR were consistent with results of previous work by others. The most significant finding of the present work was the inhibition of mercury oxidation in the presence of CO during SCR of NO at low levels of HCl. In the presence of 2 ppmv HCl, expected in combustion products from some Powder River Basin coals, an increase in CO from 0 to 50 ppmv reduced the extent of mercury oxidation from 24 {+-} 3 to 1 {+-} 4%. Further increase in CO to 100 ppmv completely suppressed mercury oxidation. In the presence of 11-12 ppmv HCl, increasing CO from 0 to {approx}120 ppmv reduced mercury oxidation from {approx}70% to 50%. Conversion of SO{sub 2} to sulfate also decreased with increasing NH{sub 3}/NO ratio, but the effects of HCl and CO in flue gas on SO{sub 2} oxidation were unclear. Oxidation and adsorption of mercury by unburned carbon and fly ash enables mercury removal in a particulate control device. A chemical kinetic mechanism consisting of nine homogeneous and heterogeneous reactions for mercury oxidation and removal was developed to interpret pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash in experiments at pilot

  20. Combustion test for RDF and coal in the 1.3 MWth ACFB

    SciTech Connect

    Kajita, A.; Tanaka, T.; Narukawa, K.; Kobayashi, N.; Nishiyama, A.; Oide, M.

    1999-07-01

    The diversification of fuel for the generating electricity becomes necessary to secure long-term energy. In this situation, coal is very important fuel resource because of great quantity of reserves under the ground and wide production area over the world. Therefore, the development of the high efficiency burning technology of coal fuel is required. The city garbage is also useful energy resource and it is socially expected the effective utilization technology with renewal energy and good for the environment. In such a background, it becomes important to know the combustion performance of RDF (Refuse Derived Fuel) in a efficient way with minimizing pollutant emissions. The authors conducted the coal and RDF burn tests using the 1.3 MW{sub th} ACFB (Atmospheric Circulating Fluidized-Bed) combustion test facility. The tests were conducted for both of 100% RDF combustion and combination of coal and RDF combustion with varied Ca contents and varied Cl contents in RDF. During combustion test, NO{sub x}, SO{sub 2} and HCl emissions in flue gas were measured. The result of the tests is reported and discussed in this paper.

  1. 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.

  2. 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.

  3. [Study on the calcium-based sorbent for removal fluorine during coal combustion].

    PubMed

    Li, Shu-ling; Qi, Qing-jie; Liu, Jian-zhong; Cao, Xin-yu; Zhou, Jun-hu; Cen, Ke-fa

    2004-03-01

    In the paper, the reaction of CaO-HF and fluorine removal mechanics at high temperature by blending calcium-based sorbents with coal during coal combustion were discussed, and test results about fluorine retention during coal combustion in fluidized bed and chain-grate furnace were reported. The results identified that lime and calcium-based sorbets developed can restratin the emission of fluorine during coal combustion. The efficiency of fluorine removal can reach 66.7%-70.0% at Ca/F 60-70 by blending lime with coal in fluidized bed combustion, and the efficiency of fluorine removal are between 57.32% and 75.19% by blending calcium-based sorbets with coal in chain-grate furnace combustion. Blending CaO or lime with coal during coal combustion can remove SO2 and HF simultaneously. PMID:15202259

  4. Structure Based Predictive Model for Coal Char Combustion

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    discussion organized into chapters whose organization is dictated by the nature of the research performed. Chapter 2 is entitled 'Experimental Work on Char Structure, Properties, and Reactivity', and focuses on fundamental structural studies at Brown using both phenollformaldehyde resin chars as model carbons and real coal chars. This work includes the first known in site high resolution TEM studies of carbonization processes, and some intriguing work on 'memory loss', a form of interaction between annealing and oxidation phenomena in chars. Chapter 3 entitled 'Computational Chemistry of Aromatic Oxidation Pathways' presents in detail the OSU work targeted at understanding the elementary molecular pathways of aromatic oxidation. Chapter 4 describes the 'Mesoscale Structural Models', using a combination of thermodynamic (equilibrium) approaches based on liquid crystal theory and kinetic simulations accounting for the effects of limited layer mobility in many fossil fuel derived carbons containing cross-linking agents. Chapter 5 entitled 'Combustion Modeling' presents work on extinction in the late stages of combustion and the development and features of the CBK8 model.

  5. Numerical modeling of pulverized coal combustion at thermal power plant boilers

    NASA Astrophysics Data System (ADS)

    Askarova, Aliya; Bolegenova, Saltanat; Maximov, Valeryi; Beketayeva, Meruyert; Safarik, Pavel

    2015-06-01

    The paper deals with development and application the numerical model for solution of processes at combustion chamber of the thermal power plant boiler. Mathematical simulation is based on solution of physical and chemical processes occuring at burning pulverized coal in the furnace model. Three-dimensional flows, heat and mass transfer, chemical kinetics of the processes, effects of thermal radiation are considered. Obtained results give quantitative information on velocity distributions, temperature and concentration profiles of the components, the amount of combustion products including harmful substances. The numerical model becomes a tool for investigation and design of combustion chambers with high-efficiency and reliable operation of boiler at thermal power plants.

  6. Land application of coal combustion by-products: Use in agriculture and land reclamation. Final report

    SciTech Connect

    Horn, M.E.

    1995-06-01

    Land application of coal combustion by-products (CCBP) can prove beneficial for a number of reasons. The data presented in this survey provide a basis for optimizing the rates and timing of CCBP applications, selecting proper target soils and crops, and minimizing adverse effects on soil properties, plant responses, and groundwater quality.

  7. CHARACTERISTICS OF SINGLE PARTICLE COAL COMBUSTION

    EPA Science Inventory

    The paper discusses the measurement of the burning history of single coal particles, using a two-color optical pyrometer. rom intensity traces at two wavelengths, information on burning times and temperatures, the duration of a volatile flame, and projected areas was obtained for...

  8. 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.

  9. 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.

  10. 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.

  11. 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. PMID:24328080

  12. 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.

  13. 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.

  14. TOXIC SUBSTANCES FROM COAL COMBUSTION: A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; T. Panagiotou; J.O.L. Wendt; W. Seames; F.E. Huggins; G.P Huffman; N. Yap; M.R. Ames; I.Olmez; T. Zeng; A.F. Sarofim; A. Kolker; R. Finkelman; J.J. Helble

    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. 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, the Massachusetts Institute of Technology (MIT), the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (W) 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{sub x} 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 the submission of the draft Phase 1 Final Report through the end of June, 1998. During this period two of the three Phase 2 coals were procured and pulverized samples were distributed to team members. Analysis of Phase 1 X-Ray Absorption Fine Structure (XAFS) data, particularly of mercury in sorbent samples, continued. An improved method for identifying mercury compounds on sorbents was developed, leading to a clearer understanding of forms of mercury in char and sorbents exposed to flue gas. Additional analysis of Phase 1 large scale combustion data was performed to investigate mechanistic information related to the fate of the radionuclides Cs, Th, and Co. Modeling work for this period was focused on building and testing a sub-model for vaporization

  15. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    PubMed

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-01

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems. PMID:23301852

  16. Combustion of Illinois coals and chars with natural gas. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Buckinus, R.O.; Peters, J.E.; Krier, H.

    1992-08-01

    The combined combustion of coal and natural gas offers advantageous compared to burning coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use due to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. Additionally, natural gas provides a clean cofiring fuel source which can enhance the usefulness of coals with high sulfur content. Addition of natural gas may reduce SO{sub x} emissions through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined Illinois coal and natural gas combustion provide particle ignition, burnout rates and ash characterization, helping clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms. The Drop Tube Furnace Facility allows detailed measurements of coal particle combustion under well-controlled conditions. The combustion characteristics of single coal particles are determined through a novel set of diagnostic techniques including in situ simultaneous measurements of particle morphology, temperature and velocity. The emphasis of the effort in the second quarter of this project was on the understanding of the ignition enhancement, burning rate processes during cofiring, and sulfur retention in the ash.

  17. 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.

  18. 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

  19. Residual carbon from pulverized coal fired boilers 1: Size distribution and combustion reactivity

    SciTech Connect

    Hurt, R.H.; Gibbins, J.R.

    1994-08-01

    The amount of residual, or unburned, carbon in fly ash is an important concern in the design and operation of pulverized coal-fired boilers. Char oxidation is the slowest step in the coal combustion process, and the rate at which this heterogeneous reaction-proceeds has an important effect on the degree of carbon burnout. There is an extensive literature on char combustion kinetics based on data in the early and intermediate stages of carbon conversion. A critical fundamental question is whether the small fraction of the fuel carbon that passes unreacted through a boiler is representative of the char during the main portion of the combustion process. This article addresses that question through a detailed characterization of eight carbon-containing fly ash samples acquired from commercial-scale combustion systems. The fly ash characterization included measurement-of joint carbon/size distribution and determination.of the combustion reactivity of the residual carbon. To minimize mineral matter interactions in the reactivity tests, the technique of incipient fluidization was developed for separation of carbon-rich extracts from the inorganic portion of the fly ash. Reactivity measurements were made at 1400--1800 K to represent conditions in pulverized coal fired boilers. Measurements were also made at 700--1100 K to. minimize transport effects and isolate the influence of char chemistry and microstructure. In both temperature regimes, the residual carbon extracts. were significantly less reactive than chars extracted from a laboratory-scale laminar flow reactor in the early-to-intermediate stages of combustion. It is concluded that the boiler environment deactivates chars, making high carbon burnout more difficult to achieve than is predicted by existing char combustion kinetic models that were developed from data on the laboratory chars. Finally, the results are used to discuss potential char deactivation mechanisms, both thermal and oxidative, in coal-fired boilers.

  20. 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.

  1. 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.

  2. Combustion of coal/water mixtures with thermal preconditioning

    SciTech Connect

    Novack, M.; Roffe, G.; Miller, G.

    1987-01-01

    Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolitalize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 1b/hr and combustor pressure of 8 atmospheres. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 350/sup 0/F to 600/sup 0/F, and combustion air was supplied at between 600/sup 0/F to 725/sup 0/F. Test durations varied between 10 to 20 minutes. The original mean coal particle size for these tests, prior to preconditioning was 25 microns. Results of additional tests showed that one-third of the sulfur contained in the solids of a coal/water mixture with 3 percent sulfur were evolved in gaseous form (under mild thermolized conditions) mainly as H/sub 2/S with the remainder as light mercaptans.

  3. 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. PMID:25997009

  4. Balancing act creating the right regulation for coal combustion waste

    SciTech Connect

    Manuel, J.

    2009-11-15

    The December 2008 collapse of a coal ash pond in Tennessee threw safe management of coal combustion waste (CCW) into the spotlight. Millions of tons of CCW are produced in the United States each year, and a large percentage of that is recycled. The US Environmental Protection Agency is pursuing a host of initiatives that could directly or indirectly affect the disposition of CCW. States, too, are taking a look at how they regulate CCW. Among the options is the possibility of regulating CCW under the Resource Conservation and Recovery Act, a move that could have far-reaching implications for both the recycling and the disposal of this waste.

  5. Beneficial use of coal combustion products continues to grow

    SciTech Connect

    MacDonald, M.

    2008-07-01

    In August 2007 the American Coal Ash Association (ACAA) released results of the Coal Combustion Products Production (CCP) and use survey. Production was 124,795,000 tons while beneficial use was 54,203,000 tons, a utilization rate of over 43%, 3% higher than in 2005. The article includes graphs of 40 years of CCP production and use and projected trade of CCP utilization until 2011. It also gives 2006 figures for Production and use of fly ash, bottom ash, boiler slag, FGD gypsum and other FGD products, and FBC ash. 3 refs., 3 figs.

  6. 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.

  7. The influence of thermal annealing on oxygen uptake and combustion rates of a bituminous coal char

    SciTech Connect

    Osvalda Senneca; Piero Salatino; Daniela Menghini

    2007-07-01

    The effect of thermal annealing on the combustion reactivity of a bituminous coal char has been investigated with a focus on the role of the formation of surface oxides by oxygen chemisorption. The combined use of thermogravimetric analysis and of analysis of the off-gas during isothermal combustion of char samples enabled the determination of the rate and extent of oxygen uptake along burn-off. Combustion was carried out at temperatures between 350 and 510{sup o}C. Char samples were prepared by controlled isothermal heat treatment of coal for different times (in the range between 1 s and 30 min) at different temperatures (in the range 900-2000{sup o}C). Results indicate that oxygen uptake is extensive along burn-off of chars prepared under mild heat treatment conditions. The maximum oxygen uptake is barely affected by the combustion temperature within the range of combustion conditions investigated. The severity of heat treatment has a pronounced effect on char combustion rate as well as on the extent and rate at which surface oxides are built up by oxygen chemisorption. Chars prepared under severe heat treatment conditions show negligible oxygen uptake and strongly reduced combustion rates. Altogether it appears that a close correlation can be established between the extent and the accessibility of active sites on the carbon surface and the combustion rate. Despite the investigation has been carried out at temperatures well below those of practical interest, results provide useful insight into the relationship existing between thermal annealing, formation of surface oxide and combustion reactivity which is relevant to the proper formulation of detailed kinetic models of char combustion. 31 refs., 6 figs., 1 tab.

  8. 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.

  9. Detection of smoldering combustion of coal with an odor meter

    SciTech Connect

    Edwards, J.C.

    1995-05-01

    A commercially available odor meter was evaluated as a detector of smoldering coal combustion, and compared with incipient carbon monoxide (CO) and hydrogen sulfide (H{sub 2}S) detection and a commercially available ionization-type smoke detector. Ten smoldering coal combustion experiments were conducted. For eight of the experiments, Pittsburgh seam coal with an average particle diameter of approximately 5 cm was heated by embedded electrical strip heaters. For two of the experiments mine size Pittsburgh seam coal was heated. Heating rates of 0.5, 0.8, and 1.1. kw were selected to provide experimental conditions characteristic of very slow and moderately fast heating for coal sample mass between 3 and 10 kg. It was found that the odor meter and smoke detector alarm had a good correlation, with the odor meter alarm occurring prior to the smoke alarm in four of the ten experiments. The odor meter gave an increase in its output signal above ambient equivalent to detecting 1 ppm of H{sub 2}S (ten times the odor threshold of H{sub 2}S) as an alarm value. This observed odor meter response occurred prior to the electrochemical detection of H{sub 2}S for five of the six experiments for which it was evaluated. In all six experiments for which the smoke optical density was evaluated, it was less than 0.023 m{sup -1} prior to the odor meter reaching alarm. In each of the eight experiments with 5 cm diameter coal particles the CO exceeded 5 ppm at odor meter alarm, while for the two experiments with mine size coal the CO was less than 3 ppm at odor meter alarm. The odor meter, as tested, is not a significant improvement over smoke and CO detectors. Because the odor meter responds to a variety of chemical compounds, with suitable modification and increased sensitivity it may be useful for detection of mine fires and thereby enhance mine safety.

  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.