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03410 Worldwide methane emissions from underground coal mining
16
Fuel science and technology (fundamental
science, analysis, instrumentation)
for secondary enriched primary combustion air, flue gas recirculation combustion air, IR camera-guided combustion control and fuzzy logic combustion control design comprise the main features of the technology. In comparison with conventional approaches to mass-burn, SYNCOM offers advantages such as 40-50% reduction of flue gas quantity, up to 50% reduction in size of air pollution control equipment, up to 50% reduction in mass air emissions and improved ash quality to ensure it can be recycled. Based on full scale testing results and comparisons of this advanced technology to the presently applied or considered regulatory requirements in Europe and the USA, the process is described in tables and diagrams. Three phase foam production for SPONCOM fight98103406 ing in underground mines Michaylov, M. and Vlasseva, E. et al. Proc. Int. Mine Venr. Congr., 6th, 1997, 305-312. Edited by Ramani, R. V., Society for Mining, Metallurgy and Exploration, Littleton, Colorado. A preparation method for three-phase foam is described. The pressurized foam is injected into porous media of gob area for fire prevention and fighting. The method includes laboratory experiments for main foam properties, as well as a mathematical optimization procedure. Optimization criteria are formulated reflecting foam application purposes. The influence of solid phase on foam heat stability is shown. Results from optimization procedure for four foam agents by varying fly ash consistency of foam are presented. A theoretical basis for the construction of a foam generator, specially constructed for generation of three-phase foam, was established. Foam qualities attained with generator are discussed. Treatment of incinerated or molten fly ash for heavy 98l63407 metals immobilization Yamaguchi, T. ef al. Eur. Pat. Appl. EP 767,150 (Cl. C04B18/10), 9 Apr 1997, JP Appl. 951257,860, 4 Ott 1995, 15 pp. A quantity of l-50 weight parts of finely divided particles of blast furnace slag having a Blame value of 54000 cm’/g to 100 weight parts of the fly ash is added to incinerated fly ash from an incinerator for waste or molten fly ash from a melting furnace to solidify the ash. The solidified mass becomes more dense and excellent in heavy metals immobilization. Treatment of sewage effluents from hot water 96/03466 processing of low-rank raw coals Makino, E. ef al. Jpn. Kokai Tokkyo Koho JP 09,253,665 [97,253,665] (Cl. C02F1/74), 30 Sep 1997, Appl. 96171,913, 27 Mar 1996, 8 pp. (In Japanese) Sewage effluents (containing trace olefins) are dosed from hot water processing of low-rank raw coals with an alkali compound to adjust the pH 9-12. The treated water is then purged with oxygen-enriched air to improve the oxidative polymerization of trace olefins and the wastewaters are coagulated at pH 1-4, precipitated and then filtered to separate polymerized olefin precipitates. Why carbon dioxide from fossil fuel burning won’t 98103409 go away Tans, P. P. Pempect. Environ. Chem., 1998, 271-291. Edited by Macalady, D. L., Oxford University Press, New York. Carbon dioxide from fossil fuel combustion, which is added to the combined atmosphere-ocean-biosphere will not leave that system, the mobile reservoirs, for an extremely long time. The extra carbon will keep moving back and forth between the mobile reservoirs in response to climatic and biological processes. Therefore, future anthropogenic greenhouse forcing of the earth’s climate will be controlled primarily by the total amount and the rate of fossil fuel burning. Humankind may have a measure of control on the storage of carbon by the terrestrial biosphere. Worldwide methane emissions from underground 98/034i 0 coal mining Saghafi, A. et al. Proc. ht. Mine Vent. Congr., 6th, 1997, 441-445. Edited by Ramani, R. V., Society for Mining, Metallurgy, and Exploration, Littleton, Colorado. Coal mining is believed to contribute up to -30% of total methane emissions from industrial activities. The 1993 level of world saleable black coal production reached almost 3.5 billion tonnes from which -65% was produced underground. Coal in underground mines can contain high quantities of methane; some deep coal seams have methane contents as high as 50 m’itonne coal. Gas is released during coal mining from the mined seam, and in a higher degree, from the neighbouring un-mined seams and gas bearing strata which are fractured as mining advances. A study undertaken to estimate the extent of methane emissions from coal mining. Measured emissions-related data were collected from most underground coal producing countries in the world. Data included methane flows in the ventilation system, in gas drainage system, in-situ gas content, methane utilization and coal production. More comprehensive data were collected from a range of gassy and on-gassy Australian mines. Residual gas content of samples from run of mine were also measured. Using the Australian data, mathematical expressions were established to evaluate methane emissions as a function of coal production and in-situ gas content for other mines. These emission models were then used to evaluate emissions for countries or coal basins without measured emissions data. CH4 emission trends from underground mining for the year 2000 and beyond were also estimated.
314
Fuel and Energy Abstracts
July 1996
16 FUEL SCIENCE AND TECHNOLOGY Fundamental Science, Analysis, Instrumentation 96lO3411 Advances In catalysts for internal reforming in high temperature fuel cells Dicks, A. L. 1. Power Sources, 1998, 71, (112). 11I-122. An attractive method of producing the hydrogen required by the present generation of fuel cells is the catalytic steam reforming of natural gas. The molten carbonate (MCFC) and solid oxide (SOFC) fuel cells operate at high enough temperatures for the endothermic steam reforming reaction to be carried out within the stack. The conventional anodes for MCFC have insufficient activity to catalyse the steam reforming of natural gas. For these cells, internal reforming can be achieved only with the addition of a separate catalyst, preferably located in close proximity to the anode. In the so-called ‘Direct Internal Reforming’ configuration, however, attack from alkali in the MCFC may severely limit the lifetime of the catalyst. State-ofthe-art SOFC permit the reforming of natural gas directly on the nickel cermet anode, but in practice, temperature variations in the cell caused by the reforming reaction may limit the amount of internal reforming possible. In addition, some external pre-reforming may be desirable to remove high molecular weight hydrocarbons from the fuel gas, which would otherwise crack to produce elemental carbon. Degradation of the SOFC anode may also be a problem when internal reforming is carried out. This has prompted several research groups to investigate the use of alternative anode materials. Advances in simulated test of biogas 9ai63412 Li, M. et al. Shiyou Yu Tianranqi Dizhi, 1996, 17, (2). 117-122. (In Chinese) The method of suspended inocula is a primary advance in the biogas simulation test. That is to say, by discarding most of the inactive organic matter of the first time cultured micro-organisms, propagated the active ones and cultured for the second time so as to improve their density and activity. This method could reduce the biogas produced by inocula themselves and shorten test period. When test temperature increased to 75°C the bacteria could still be alive and produce methane. The simulation tests made on coal and crude oil show that, under anaerobic condition, they can be degraded and can produce methane, which is also one of the reasons of forming dense oil. Furthermore, source producing methane bacteria were obtained from crude oil in this simulation test. 9aio34i 3 Aeration-type unit with a standpipe for controlled injection of powder feed into a fluidized bed reactor Eastham, D. H. et al. Eur. Pat. Appl. EP 798,037 (Cl. BOlJ8/00), I Ott 1997, US Appl. 623,071, 28 Mar 1996, 8 pp. The process involves mixing the powder feed which is then aerated in an auxiliary fluidized bed or a similar apparatus and passed downward in a stand-pipe toward the fluidized-bed reactor. It is subsequently injected with auxiliary gas to decrease the velocity in the standpipe and fed into the fluidized bed reactor for processing. Near the bottom of the standpipe there is a bend and the powder flow is controlled to prevent local fluidization during the feed. The process is suitable for feed of the powder mixtures having particle size of l-5000 ,Im, especially for the blends of coke and TiOz-ore powders for roasting in a fluidized bed. 96103414 Analysis of heat economy influenced by different mode of steam supply in thermal power unit Xing, Q. et al. Xi’an Jiaotong Dame Xuebao, 1996, 30, (5), 104-110. (In Chinese) A quantitative analysis was performed on the heat economy and its difference between the mode of direct and indirect steam supplying. The principles and calculation method were given by which the rate of coal consumption of indirect supplying steam mode is converted into that of direct supplying steam mode. The method is suitable for design and operation analysis of thermal power plant. gal0341 5 Application of the advanced zone-by-zone method in computation of furnaces firing fossil fuels Kouprianov, V. I. et al. Sustainable Energy Environ. Technol., Proc. AsiaPac. Conf., 1996, 330-339. Edited by Greenfield, P. F., World Scientific, Singapore. Considered here is an algorithm of a zero-dimensional zone-by-zone method of furnace computation. It is possible to obtain a number of furnace thermal characteristics with this method providing arbitrary distribution of fuel, air and recirculating gases through burner tiers. The correlation between a burnout function with respect to the furnace height and heat losses with unburned carbon and/or due to incomplete combustion is proposed. For various furnace designs, composition of fuels and combus-
Fuel science and technology (fundamental
science, analysis, instrumentation)
for secondary enriched primary combustion air, flue gas recirculation combustion air, IR camera-guided combustion control and fuzzy logic combustion control design comprise the main features of the technology. In comparison with conventional approaches to mass-burn, SYNCOM offers advantages such as 40-50% reduction of flue gas quantity, up to 50% reduction in size of air pollution control equipment, up to 50% reduction in mass air emissions and improved ash quality to ensure it can be recycled. Based on full scale testing results and comparisons of this advanced technology to the presently applied or considered regulatory requirements in Europe and the USA, the process is described in tables and diagrams. Three phase foam production for SPONCOM fight98103406 ing in underground mines Michaylov, M. and Vlasseva, E. et al. Proc. Int. Mine Venr. Congr., 6th, 1997, 305-312. Edited by Ramani, R. V., Society for Mining, Metallurgy and Exploration, Littleton, Colorado. A preparation method for three-phase foam is described. The pressurized foam is injected into porous media of gob area for fire prevention and fighting. The method includes laboratory experiments for main foam properties, as well as a mathematical optimization procedure. Optimization criteria are formulated reflecting foam application purposes. The influence of solid phase on foam heat stability is shown. Results from optimization procedure for four foam agents by varying fly ash consistency of foam are presented. A theoretical basis for the construction of a foam generator, specially constructed for generation of three-phase foam, was established. Foam qualities attained with generator are discussed. Treatment of incinerated or molten fly ash for heavy 98l63407 metals immobilization Yamaguchi, T. ef al. Eur. Pat. Appl. EP 767,150 (Cl. C04B18/10), 9 Apr 1997, JP Appl. 951257,860, 4 Ott 1995, 15 pp. A quantity of l-50 weight parts of finely divided particles of blast furnace slag having a Blame value of 54000 cm’/g to 100 weight parts of the fly ash is added to incinerated fly ash from an incinerator for waste or molten fly ash from a melting furnace to solidify the ash. The solidified mass becomes more dense and excellent in heavy metals immobilization. Treatment of sewage effluents from hot water 96/03466 processing of low-rank raw coals Makino, E. ef al. Jpn. Kokai Tokkyo Koho JP 09,253,665 [97,253,665] (Cl. C02F1/74), 30 Sep 1997, Appl. 96171,913, 27 Mar 1996, 8 pp. (In Japanese) Sewage effluents (containing trace olefins) are dosed from hot water processing of low-rank raw coals with an alkali compound to adjust the pH 9-12. The treated water is then purged with oxygen-enriched air to improve the oxidative polymerization of trace olefins and the wastewaters are coagulated at pH 1-4, precipitated and then filtered to separate polymerized olefin precipitates. Why carbon dioxide from fossil fuel burning won’t 98103409 go away Tans, P. P. Pempect. Environ. Chem., 1998, 271-291. Edited by Macalady, D. L., Oxford University Press, New York. Carbon dioxide from fossil fuel combustion, which is added to the combined atmosphere-ocean-biosphere will not leave that system, the mobile reservoirs, for an extremely long time. The extra carbon will keep moving back and forth between the mobile reservoirs in response to climatic and biological processes. Therefore, future anthropogenic greenhouse forcing of the earth’s climate will be controlled primarily by the total amount and the rate of fossil fuel burning. Humankind may have a measure of control on the storage of carbon by the terrestrial biosphere. Worldwide methane emissions from underground 98/034i 0 coal mining Saghafi, A. et al. Proc. ht. Mine Vent. Congr., 6th, 1997, 441-445. Edited by Ramani, R. V., Society for Mining, Metallurgy, and Exploration, Littleton, Colorado. Coal mining is believed to contribute up to -30% of total methane emissions from industrial activities. The 1993 level of world saleable black coal production reached almost 3.5 billion tonnes from which -65% was produced underground. Coal in underground mines can contain high quantities of methane; some deep coal seams have methane contents as high as 50 m’itonne coal. Gas is released during coal mining from the mined seam, and in a higher degree, from the neighbouring un-mined seams and gas bearing strata which are fractured as mining advances. A study undertaken to estimate the extent of methane emissions from coal mining. Measured emissions-related data were collected from most underground coal producing countries in the world. Data included methane flows in the ventilation system, in gas drainage system, in-situ gas content, methane utilization and coal production. More comprehensive data were collected from a range of gassy and on-gassy Australian mines. Residual gas content of samples from run of mine were also measured. Using the Australian data, mathematical expressions were established to evaluate methane emissions as a function of coal production and in-situ gas content for other mines. These emission models were then used to evaluate emissions for countries or coal basins without measured emissions data. CH4 emission trends from underground mining for the year 2000 and beyond were also estimated.
314
Fuel and Energy Abstracts
July 1996
16 FUEL SCIENCE AND TECHNOLOGY Fundamental Science, Analysis, Instrumentation 96lO3411 Advances In catalysts for internal reforming in high temperature fuel cells Dicks, A. L. 1. Power Sources, 1998, 71, (112). 11I-122. An attractive method of producing the hydrogen required by the present generation of fuel cells is the catalytic steam reforming of natural gas. The molten carbonate (MCFC) and solid oxide (SOFC) fuel cells operate at high enough temperatures for the endothermic steam reforming reaction to be carried out within the stack. The conventional anodes for MCFC have insufficient activity to catalyse the steam reforming of natural gas. For these cells, internal reforming can be achieved only with the addition of a separate catalyst, preferably located in close proximity to the anode. In the so-called ‘Direct Internal Reforming’ configuration, however, attack from alkali in the MCFC may severely limit the lifetime of the catalyst. State-ofthe-art SOFC permit the reforming of natural gas directly on the nickel cermet anode, but in practice, temperature variations in the cell caused by the reforming reaction may limit the amount of internal reforming possible. In addition, some external pre-reforming may be desirable to remove high molecular weight hydrocarbons from the fuel gas, which would otherwise crack to produce elemental carbon. Degradation of the SOFC anode may also be a problem when internal reforming is carried out. This has prompted several research groups to investigate the use of alternative anode materials. Advances in simulated test of biogas 9ai63412 Li, M. et al. Shiyou Yu Tianranqi Dizhi, 1996, 17, (2). 117-122. (In Chinese) The method of suspended inocula is a primary advance in the biogas simulation test. That is to say, by discarding most of the inactive organic matter of the first time cultured micro-organisms, propagated the active ones and cultured for the second time so as to improve their density and activity. This method could reduce the biogas produced by inocula themselves and shorten test period. When test temperature increased to 75°C the bacteria could still be alive and produce methane. The simulation tests made on coal and crude oil show that, under anaerobic condition, they can be degraded and can produce methane, which is also one of the reasons of forming dense oil. Furthermore, source producing methane bacteria were obtained from crude oil in this simulation test. 9aio34i 3 Aeration-type unit with a standpipe for controlled injection of powder feed into a fluidized bed reactor Eastham, D. H. et al. Eur. Pat. Appl. EP 798,037 (Cl. BOlJ8/00), I Ott 1997, US Appl. 623,071, 28 Mar 1996, 8 pp. The process involves mixing the powder feed which is then aerated in an auxiliary fluidized bed or a similar apparatus and passed downward in a stand-pipe toward the fluidized-bed reactor. It is subsequently injected with auxiliary gas to decrease the velocity in the standpipe and fed into the fluidized bed reactor for processing. Near the bottom of the standpipe there is a bend and the powder flow is controlled to prevent local fluidization during the feed. The process is suitable for feed of the powder mixtures having particle size of l-5000 ,Im, especially for the blends of coke and TiOz-ore powders for roasting in a fluidized bed. 96103414 Analysis of heat economy influenced by different mode of steam supply in thermal power unit Xing, Q. et al. Xi’an Jiaotong Dame Xuebao, 1996, 30, (5), 104-110. (In Chinese) A quantitative analysis was performed on the heat economy and its difference between the mode of direct and indirect steam supplying. The principles and calculation method were given by which the rate of coal consumption of indirect supplying steam mode is converted into that of direct supplying steam mode. The method is suitable for design and operation analysis of thermal power plant. gal0341 5 Application of the advanced zone-by-zone method in computation of furnaces firing fossil fuels Kouprianov, V. I. et al. Sustainable Energy Environ. Technol., Proc. AsiaPac. Conf., 1996, 330-339. Edited by Greenfield, P. F., World Scientific, Singapore. Considered here is an algorithm of a zero-dimensional zone-by-zone method of furnace computation. It is possible to obtain a number of furnace thermal characteristics with this method providing arbitrary distribution of fuel, air and recirculating gases through burner tiers. The correlation between a burnout function with respect to the furnace height and heat losses with unburned carbon and/or due to incomplete combustion is proposed. For various furnace designs, composition of fuels and combus-