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03501 Kinetics of evolution of low-molecular weight products during metamorphism of coals
01
So/id fuels (sources, winning, propeffies)
01
98163495 Determination of the etheric oxygen in maceral fractions of high rank coals
SOLID FUELS Sources,
96iO3489 Denmark
Winning,
Properties
Ash deposition trials at three power stations in
Laursen, K. et al. Energy Fuels, 1998, 12, (2) 429-442. Three power stations in Denmark, Ensted, Funen, and Vendayssel, were the sites for six full-scale trials. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analysed with various techniques. Based on SEM analyses, the deposits can be grouped into five textural types, all possessing distinct textural and chemical characteristics. Likewise, the deposition mechanisms for these five types are characteristic and they may be used for constructing a model for the buildup and maturation of an ash deposit. The deposits were thin (maximum 2 mm after 9 h) and the influence of operational parameters and probe temperatures on the magnitude of the deposits were minor. The probe temperatures had no influence on the composition of the ash deposits for coals with low ash deposition propensities, whereas the probe temperature did influence the composition of deposits for coals with medium ash deposition propensities. These results may indicate that coals with medium to high ash deposition propensities in existing boilers may cause increasing ash deposit formation in future boilers with higher steam temperatures (620-700°C).
Chemical physics of the fractal polyconjugated 93l03490 systems. Part Ill. Synergistic physicochemical model of coal, rock, and gas outbursts (review) Lyubchenko, L. S. and Lyubchenko, M. L. Khim. Fiz., 1997, 16, (12). 2036. (In Russian) Synergistic physicochemical model and fractal kinetics of plastic deformation of a composite, synergistic physicochemical model of coal outburst and EPR-spectroscopic criterion of coal outburst hazard are among the topics .. atscussea.
98103491
Coal properties and their influence on air activation
Kopp, 0. C. et al. Carbon, 1997, 35, (12) 1765-1779. The objective of this research was to determine the influence of the properties of a raw coal on the degree to which it may be activated. Using thermogravimetry, mass spectroscopy, mercury porosimetry, nitrogen sorption and infrared spectroscopy, and activated in air, water-saturated helium and carbon dioxide, 12 coals were analysed. The greatest amounts of surface area using air activation were generated for bituminous coals. A spline-fitting programme was used to generate a curve that encloses the surface areas generated for all samples to investigate possible reasons for the sample-to-sample variation in the amount of surface area generated. The differences between measured surface areas and surface areas predicted by the spline-fitting program were also determined.
A comparative classification of coal reactivity gal03492 Zolin, A. et al. DGMK Tagungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 991-994. A qualitative reactivity classification of nine different coals, ranking from sub-bituminous to low volatile bituminous with respect to one coal, Cerrejon, is presented, based on thermogravimetric analysis (TGA) tests. Good agreement is found between the classification and a corresponding one obtained from another study by entrained flow reactor (EFR) experiments. Two Southern Hemisphere coals (Australia), however, showed a higher reactivity with respect to the Northern Hemisphere coal Cerrejon (Colombia) in the low temperature TGA experiments. TGA seems able to provide a simple means for determining a fuel reactivity classification that may be applied to full-scale suspension fired plants. To determine the activation energy and reaction order of the Cerrejon coal, its combustion behaviour was investigated at different temperatures and oxveen concentrations. In addition. TGA tests revealed that increasing values of the heat treatment temperature and holding time during pyrolysii result in lower char reactivities for this coal. This is attributed to the severity of the pyrolysis process and thereby the influence of thermal annealing effects. Composition and properties of macerals of with a low degree of metamorphism gal03493
COSIS
Gagarin, S. G. Koks K&m., 1997, (ll), 2-7. (In Russian) The elemental composition, technological properties, and X-ray analysis data of liptinite, vitrinite, and inertinite isolated from a low-rank Polish and a low-rank Donbass (Russia) coal was evaluated via regression analysis. It is concluded that these coals have a similar maceral structure.
Contents of trace elements in brown coal from European and world fields. Ill. Part 1
93lo3494
Bouska, V. et al.
332
Uhli-Rudy-Geol. Pruzkum, 1998.5, (l), 21-29. (In Czech)
Fuel and Energy Abstracts
September 1996
Straka, P. et al. -Acta Mont., Ser. B, 1997, 7, 63-71. Diffuse reflectance IR Fourier transform spectroscopy (DRIFTS) was combined with the partial least squares (PLS) method to determine etheric oxygen in chemical and physical heterogeneous maceral fractions of bituminous coals. The DRIFTS-PLS method yields exact and accurate results, as demonstrated by the determination of etheric oxygen in 26 standards and 14 samples of coal maceral fractions. The method reduces the duration of the determination from tens of hours to several minutes, making it suitable for analyses of large sets of heterogeneous samples.
98103496 Development of the Erunakovsky deposit as a foundation for coal-mining potential of Kuzbass Bragin, V. E. Ugol’, 1997, (12) 11-12. (In Russian) The author discusses a project for the development of the Erunakovsky deposit of the Kuzbass region, Russia, focusing on its economical ecological advantages.
coal and
Energetics of solid rocket fuels with a decreased ecological danger
9alo3497
Lemjpert, D. B. ef al. K/rim. Fiz., 1997, 16, (9) 91-100. (In Russian) For the first stage of rocket system, the thermodynamic search is being carried out for the composition of the solid rocket fuel mixture. The system that does not contain perchlorates as source of release of gaseous hydrogen chloride and that contains perchlorate in stoichiometric ratio with sodium or lithium that leads to the formation of condensed chlorides. The work considers various methods of release metals in the composition. The energy feasibility of the compositions is analysed.
96io3498
Evaluation method of coal quality
Saito, S. et al. Jpn. Kokai Tokkyo Koho JP 10 19,814 [98 19.8141 (Cl. GOlN24/08), 23 Jan 1998, Appl. 96/177,776,8 Jul 1996,5 pp. (In Japanese) A coal quality evaluation method in the manufacture of metallurgical coke by coke oven comprises swelling the coal by heavy hydrogen-substituted solvent, measuring NMR spectrum of hydrogen nuclei, quantitatively determining the total amount of hydrogen in the coal, calculating the ratio of the amount of hydrogen participated in hydrogen bonds to the total hydrogen amount and obtaining the relation of the ratio and coke drum index for coking characterization. gal03499
How coal properties affect NO. emissions and loss-
on-ignition Mereb, J. B. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996) 381-387. Equipped with a low-NO, burner, the CONSOL research combustor was used to assess the impact of coal properties on NO, emissions and loss-onignition (LOI). The coals ranged in rank from lignite to low-volatile bituminous and the property variables were volatile matter content, nitrogen content, pulverized coal fineness and coal rank. The greatest effect on NO, emissions was exerted by volatile matter content, followed by coal rank, nitrogen content and coal fineness. Coal rank was the property with the greatest effect on LOI; lower rank coals produced lower LOI. LO1 correlated strongly with the oxygen content of the coal (a measure of reactivity and rank) and the coal ash content. 93lo3500 Investigation of ignition behavior of solid fuels Smag, A. et al. DGMK Tugungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 987-990. As a representative of solid fuels such as coal and coke, activated coal was subjected to burning by oxygen. Besides the original activated coal, coals containing catalysts obtained by the impregnation of inorganic salt solutions on coal have also been used in the experiments. The effects of studying conditions and the type of catalyst on the ignition temperature of the specimens were investigated. The catalytic effect of alkali metal hydroxides on the burning reaction is higher than those of other salts. Ignition temperature was found to decrease as the concentration of a great number of salts which show catalytic action increased. By means of the thermogravimetric method, the burning properties of some specimens have also been determined.
98103501 Kinetics of evolution of low-molecular products during metamorphism of coals
weight
Gagarin, S. G. and Eremin, 1. V. Khim. Tverd. Top/., 1997, (4), 3-11. (In Russian) A set ofdifferential equations as a function of vitrinite reflectance is used to describe the kinetics of evolution of carbon dioxide, water, methane, alkanes, etc., during coal metamorphism. For a range of coals varying in rank, the rate constants for evolution of these low-molecular-weight products are determined. 93io3502 Laboratory assessment of technological properties of lignltes from the Ptolemals and Megalopolls fields, Greece Michailidis, K. et al. Oryktos Ploutos, 1997,~105,-43-48. For the quality assessment of lignites from Ptolemais and Megalopolis fields, Greece, standardized methods have been used. These lignites were characterized by low calorific values, high contents of moisture, volatile
So/id fuels (sources, winning, propeffies)
01
98163495 Determination of the etheric oxygen in maceral fractions of high rank coals
SOLID FUELS Sources,
96iO3489 Denmark
Winning,
Properties
Ash deposition trials at three power stations in
Laursen, K. et al. Energy Fuels, 1998, 12, (2) 429-442. Three power stations in Denmark, Ensted, Funen, and Vendayssel, were the sites for six full-scale trials. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analysed with various techniques. Based on SEM analyses, the deposits can be grouped into five textural types, all possessing distinct textural and chemical characteristics. Likewise, the deposition mechanisms for these five types are characteristic and they may be used for constructing a model for the buildup and maturation of an ash deposit. The deposits were thin (maximum 2 mm after 9 h) and the influence of operational parameters and probe temperatures on the magnitude of the deposits were minor. The probe temperatures had no influence on the composition of the ash deposits for coals with low ash deposition propensities, whereas the probe temperature did influence the composition of deposits for coals with medium ash deposition propensities. These results may indicate that coals with medium to high ash deposition propensities in existing boilers may cause increasing ash deposit formation in future boilers with higher steam temperatures (620-700°C).
Chemical physics of the fractal polyconjugated 93l03490 systems. Part Ill. Synergistic physicochemical model of coal, rock, and gas outbursts (review) Lyubchenko, L. S. and Lyubchenko, M. L. Khim. Fiz., 1997, 16, (12). 2036. (In Russian) Synergistic physicochemical model and fractal kinetics of plastic deformation of a composite, synergistic physicochemical model of coal outburst and EPR-spectroscopic criterion of coal outburst hazard are among the topics .. atscussea.
98103491
Coal properties and their influence on air activation
Kopp, 0. C. et al. Carbon, 1997, 35, (12) 1765-1779. The objective of this research was to determine the influence of the properties of a raw coal on the degree to which it may be activated. Using thermogravimetry, mass spectroscopy, mercury porosimetry, nitrogen sorption and infrared spectroscopy, and activated in air, water-saturated helium and carbon dioxide, 12 coals were analysed. The greatest amounts of surface area using air activation were generated for bituminous coals. A spline-fitting programme was used to generate a curve that encloses the surface areas generated for all samples to investigate possible reasons for the sample-to-sample variation in the amount of surface area generated. The differences between measured surface areas and surface areas predicted by the spline-fitting program were also determined.
A comparative classification of coal reactivity gal03492 Zolin, A. et al. DGMK Tagungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 991-994. A qualitative reactivity classification of nine different coals, ranking from sub-bituminous to low volatile bituminous with respect to one coal, Cerrejon, is presented, based on thermogravimetric analysis (TGA) tests. Good agreement is found between the classification and a corresponding one obtained from another study by entrained flow reactor (EFR) experiments. Two Southern Hemisphere coals (Australia), however, showed a higher reactivity with respect to the Northern Hemisphere coal Cerrejon (Colombia) in the low temperature TGA experiments. TGA seems able to provide a simple means for determining a fuel reactivity classification that may be applied to full-scale suspension fired plants. To determine the activation energy and reaction order of the Cerrejon coal, its combustion behaviour was investigated at different temperatures and oxveen concentrations. In addition. TGA tests revealed that increasing values of the heat treatment temperature and holding time during pyrolysii result in lower char reactivities for this coal. This is attributed to the severity of the pyrolysis process and thereby the influence of thermal annealing effects. Composition and properties of macerals of with a low degree of metamorphism gal03493
COSIS
Gagarin, S. G. Koks K&m., 1997, (ll), 2-7. (In Russian) The elemental composition, technological properties, and X-ray analysis data of liptinite, vitrinite, and inertinite isolated from a low-rank Polish and a low-rank Donbass (Russia) coal was evaluated via regression analysis. It is concluded that these coals have a similar maceral structure.
Contents of trace elements in brown coal from European and world fields. Ill. Part 1
93lo3494
Bouska, V. et al.
332
Uhli-Rudy-Geol. Pruzkum, 1998.5, (l), 21-29. (In Czech)
Fuel and Energy Abstracts
September 1996
Straka, P. et al. -Acta Mont., Ser. B, 1997, 7, 63-71. Diffuse reflectance IR Fourier transform spectroscopy (DRIFTS) was combined with the partial least squares (PLS) method to determine etheric oxygen in chemical and physical heterogeneous maceral fractions of bituminous coals. The DRIFTS-PLS method yields exact and accurate results, as demonstrated by the determination of etheric oxygen in 26 standards and 14 samples of coal maceral fractions. The method reduces the duration of the determination from tens of hours to several minutes, making it suitable for analyses of large sets of heterogeneous samples.
98103496 Development of the Erunakovsky deposit as a foundation for coal-mining potential of Kuzbass Bragin, V. E. Ugol’, 1997, (12) 11-12. (In Russian) The author discusses a project for the development of the Erunakovsky deposit of the Kuzbass region, Russia, focusing on its economical ecological advantages.
coal and
Energetics of solid rocket fuels with a decreased ecological danger
9alo3497
Lemjpert, D. B. ef al. K/rim. Fiz., 1997, 16, (9) 91-100. (In Russian) For the first stage of rocket system, the thermodynamic search is being carried out for the composition of the solid rocket fuel mixture. The system that does not contain perchlorates as source of release of gaseous hydrogen chloride and that contains perchlorate in stoichiometric ratio with sodium or lithium that leads to the formation of condensed chlorides. The work considers various methods of release metals in the composition. The energy feasibility of the compositions is analysed.
96io3498
Evaluation method of coal quality
Saito, S. et al. Jpn. Kokai Tokkyo Koho JP 10 19,814 [98 19.8141 (Cl. GOlN24/08), 23 Jan 1998, Appl. 96/177,776,8 Jul 1996,5 pp. (In Japanese) A coal quality evaluation method in the manufacture of metallurgical coke by coke oven comprises swelling the coal by heavy hydrogen-substituted solvent, measuring NMR spectrum of hydrogen nuclei, quantitatively determining the total amount of hydrogen in the coal, calculating the ratio of the amount of hydrogen participated in hydrogen bonds to the total hydrogen amount and obtaining the relation of the ratio and coke drum index for coking characterization. gal03499
How coal properties affect NO. emissions and loss-
on-ignition Mereb, J. B. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996) 381-387. Equipped with a low-NO, burner, the CONSOL research combustor was used to assess the impact of coal properties on NO, emissions and loss-onignition (LOI). The coals ranged in rank from lignite to low-volatile bituminous and the property variables were volatile matter content, nitrogen content, pulverized coal fineness and coal rank. The greatest effect on NO, emissions was exerted by volatile matter content, followed by coal rank, nitrogen content and coal fineness. Coal rank was the property with the greatest effect on LOI; lower rank coals produced lower LOI. LO1 correlated strongly with the oxygen content of the coal (a measure of reactivity and rank) and the coal ash content. 93lo3500 Investigation of ignition behavior of solid fuels Smag, A. et al. DGMK Tugungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 987-990. As a representative of solid fuels such as coal and coke, activated coal was subjected to burning by oxygen. Besides the original activated coal, coals containing catalysts obtained by the impregnation of inorganic salt solutions on coal have also been used in the experiments. The effects of studying conditions and the type of catalyst on the ignition temperature of the specimens were investigated. The catalytic effect of alkali metal hydroxides on the burning reaction is higher than those of other salts. Ignition temperature was found to decrease as the concentration of a great number of salts which show catalytic action increased. By means of the thermogravimetric method, the burning properties of some specimens have also been determined.
98103501 Kinetics of evolution of low-molecular products during metamorphism of coals
weight
Gagarin, S. G. and Eremin, 1. V. Khim. Tverd. Top/., 1997, (4), 3-11. (In Russian) A set ofdifferential equations as a function of vitrinite reflectance is used to describe the kinetics of evolution of carbon dioxide, water, methane, alkanes, etc., during coal metamorphism. For a range of coals varying in rank, the rate constants for evolution of these low-molecular-weight products are determined. 93io3502 Laboratory assessment of technological properties of lignltes from the Ptolemals and Megalopolls fields, Greece Michailidis, K. et al. Oryktos Ploutos, 1997,~105,-43-48. For the quality assessment of lignites from Ptolemais and Megalopolis fields, Greece, standardized methods have been used. These lignites were characterized by low calorific values, high contents of moisture, volatile