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00334 Effect of heat treatment temperature on coal char gasification reactivity
03
Gaseous fuels
(derived
gaseous fuels)
proper monitoring of the main mixing gas stream, reporting its component analysis as well as calorific value, which can then be used for the control of the ratio of coke oven gas and blast furnace gas to optimize energy consumption and flue gas emission.
Catalytic hydrogenation of brown coals from 97100324 Kansk-Achinsk (Russia) and Yallourn (Australia) basins to clean liquid fuels Kageyama, Y., Chem. Sustainable Dev., 1996, 4, (I). 37-44. This provides a comparative analysis of the prdperties of brown coals from the world largest brown coals basins-Kansk-Achinsk (Russia) and Yallourn (Australia) with respect to the production of alternative liquid hydrocarbon fuel.
Catalytic upgrading 97100325 study with model components
of tarry fuel gases:
a kinetic
Jess A., Chemical Engineering and Pmcessing, Dec. 1996, 35, (6) 487-494. As a contribution to the development of a process for catalytic upgrading of tarry fuel gases, e.g. coke-oven gas, the conversion of naphthalene, benzene and methane on a nickel catalyst in the presence of HZ and Hz0 was studied. The experiments were performed in a tubular flow reactor. The kinetic data were obtained by systematic variation of the reaction conditions. At temperatures of more than 800°C. each hydrocarbon is cracked and converted with HZ0 to CO and HZ. Soot formation does not occur at any temperature. In case of simultaneous conversion of all three hydrocarbons, competitive reactions have to be considered. The rate of chemical reaction on the catalyst is substantially decreased in the presence of HzS. Nevertheless, in a reactor of industrial scale, HtS has only slight influence. The catalyst would be applied with a particle drameter of I9 mm (experiments: I.5 mm), and the overall reaction rate of hydrocarbon conversion is significantly affected by gas film diffusion.
97100326 Characteristics in a drop tube reactor
of entrained
flow coal gasification
Lee, J. G. et al., Reel, 1996, 75, (9), 1035-1042. The effects of reaction temperature, oxygen/coal and steam/coal ratios and residence time on coal gasification performance in entrained flow were determined by means of a drop tube reactor. The hydrogen/carbon monoxide molar ratio decreases with increasing reaction temperature and the hydrogen/carbon monoxide content of the product gas exhibit a maximum around the ash fusion temperature. With increasing oxygen content, carbon conversion increases and the rate of production of hydrogen/carbon monoxide increases initially to a maximum value. The optimum oxygen/coal ratio is in the range 0.6-0.9 for different coals.
97100327 Characterization of organic and inorganic by-products from field-scale gasification/incinerator for waste tires Koo, J. and Kim, S., Toxicol. Environ. Chem., 1995, 52, (l-4) 203-213. The objective of this study is to establish experitintally the distribution of gasification products such as condensed and noncondensed fuel, inorganic gas, and residue generated from the field-scale gasification incinerator connected directly with a batch type gasifier of waste tires. In the gasification reactor injecting air, the reaction takes place in two steps, the first one being true pyrolysis and the second one being the gasification step. In the field-scale gasification process, a greater portion of oil (200-300 mg oil/m’) is produced at the beginning of the gasification process, and it is controlled by the initial pyrolysis reaction. A greater amount of noncondensed fuel is produced in the middle of the gasification process, The hydrocarbon distribution of the condensable product consists of various aromatic compounds such as naphthalene, I-limonene, methylbenzene, and so on. The zinc content of the ash is the highest, with the exception of iron, and Si, Ai, Ca, Cu, Ni, S, and Cd are also noted. Toxic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) and other organics are contained in the bottom and fly ash.
97100328
CO2 gasification
of iron loaded carbon
Tanaka, S. et al., Sekitan Kagaku Kaigi Happyo Ronhunshu, 1993, 30, hl70. (In Japanese) Carbon dioxide gasification of iron-loaded Yallourn coal, carbon black, and active carbon was carried out in a thermobalance. The sample was heated to 800°C under argon and then gasified with carbon dioxide. When the sample was treated at 780 to approximately 800°C with carbon monoxide for I20 s, a rapid weight decrease was observed for selected samples. Such rapid gasification was attributed to the highly dispersed state of iron on the carbon species.
97100329 Continuous content of carbonaceous
measurement of change in oxygen materials during the gasification
Miura, K. et al., Sekitart Kagaku Kaigi Happyo Ror~hunshu, 1993. 30, 63-66. (In Japanese) Oxygen uptake on carbon materials during gasification was estimated by continuously measuring the atmospheric change and the composition of the gaseous products (using a sensitive thermobalance and a mass spectrometer). Step response experiments for 1802 injections were also performed to examine transient behaviour during gasification. The role of adsorbed oxygen in the gasification mechanism was examinedd based on these experiments.
24
Fuel and Energy Abstracts
January 1997
97100330
Development
of materials
for coal gasification
Kihara, S., Fushoku Boshoku Bumon Iinkai Shir)?o (Nippon Zairyo Gakkai), 1996, 192, 34-45. (In Japanese) This paper examines the various corrosion testing results of the materials for coal gasification. Sulfide-based corrosion occurs during high-temperature operation of the coal gasification approach.
97100331 temperature
Differences in ash deposit in an entrained-bed gasifier
form
caused
by wall
Sekitan Kagaku Kaigi Happy0 Rordw~rhtr, 1994. 31. 4XKoyama, S. et al., 51. (In Japanese) Laborary scale apparatus equipped with the wall temperature control device was used to study the adhesion and the deposition behaviour of coal ash on the gasifier wall. The ash melting temperature and the sintering temperature seemed to influence the adhesion force and the deposit form considerably. When wall temperature was below sintering temperature, the deposit was powder-ash with very weak adhesion. Between melting temperature and sintering temperature, the deposit was sintered-lump with strong adhesion. At nearly melting temperature, solid-slag was formed. It could be detached by mechanical action.
97100332 gasification
The diffusion-reaction of coal char particles
system of high temperature
Sekitan Kagaku Kotgi Happy0 Ronhttmhu, 1993. 30, Lin, S. and Horio, M., 55-58. (In Japanese) In this study the diffusion-reaction systems of high temperature gasification in coal char particles were investigated experimentally. Results were analysed taking in to account the effectiveness factors to obtain the gasification rate constants free from mass transfer resistance.
97100333 Dynamics of surface bon gasification with oxygen
oxygen
complex
during
car-
Sekitan Kagaku Kaigi Happyo Rottt+n.shu, 1994, 3 I, 36Zhuang, Q. et al, 39. (In Japanese) Transient kinetics was used to study the dynamic behaviour of surface oxygen complexes formed during the gasification of carbon with isotopically labelled oxygen. The surface oxygen complexes after the gasification were analysed with temperature programmed desorption. A mechanism has been proposed from the present study, together with a former study on the chemical form of surface complexes. It is proved that combination of techniques, such as TPD, TK, DRIFT and isotope labelling could be a powerful means to clarify the mechanism of carbon gasification with oxygen.
97100334 gasification
Effect of heat treatment reactivity
temperature
on coal char
Morishita. K. et al., Sekitan Kagaku Kaigi Happy0 Ronhumhu, 1095, 32, 228-231. (In Japanese) Characterizes the physical and chemical properties of chars obtained from different rank coals by oxygen gasification, TPD technique, and BET method.
97100335 The effect of mineral matter and pyrolysis conditions on the gasification of Greek lignite by carbon dioxide Samaras, P. et al., Fuel, 1996, 75, (9), 1108-l 114. Experiments conducted for this article involved the production of specimens with different mineral matter contents from Greek lignite using various acid treatment conditions. Ash content and chemical composition of mineral matter depended on the type of acid used and the sequence of the treatment stages. Gasification rates of coals were investigated by thermogravimetric analysis in a carbon dioxide atmosphere in the temperature range 700-900°C. Details the combined effects of components and carbonization conditions.
97100336 gasification
Effects of gasifying agent rate of Taiheiyo coal char
composition
on
the
Tsuji, T. et al., Kagaku Kogaku Ronhunshu, 1996, 22, (4). 794-800. (In Japanese) This paper looks at the steam gasification of Taiheiyo coal char. This was carried out in order to determine gasification kinetics taking account of the concentration dependence of coexisting gases of Hz, CO?. CO and OZ. Gasification tests were conducted with five different gas mixtures as gasifying agents at atmospheric pressure and over a temperature range of 1073 to 1273 K using a differential fixed bed reactor. The reaction rate equation was expressed by such functions as temperature, partial pressure of the gases, changes of pore structure and surface area of char and unconverted carbon fraction of the char. The dependence of the gasification rate on the partial pressure of HzO, COr and CO was able to be expressed by Langmuir-Hinshelwood kinetics which accounts for the decrease in the rate due to coexistence of Hz and CO. The partial pressure of CO2 had little effect on the rate in the HaO-CO2 gasification because the reaction rate of HZ0 is greater than COZ. The reaction rate of the char with Oa depends on the diffusion coefficient of Oz in the mixed gas. The rate equation based on the shrinking sphere model was in good agreement with the experimental result. The dependence of the steam reaction rate on the unconverted carbon fraction of partially burned char is almost the same as that of the char before burning.
Gaseous fuels
(derived
gaseous fuels)
proper monitoring of the main mixing gas stream, reporting its component analysis as well as calorific value, which can then be used for the control of the ratio of coke oven gas and blast furnace gas to optimize energy consumption and flue gas emission.
Catalytic hydrogenation of brown coals from 97100324 Kansk-Achinsk (Russia) and Yallourn (Australia) basins to clean liquid fuels Kageyama, Y., Chem. Sustainable Dev., 1996, 4, (I). 37-44. This provides a comparative analysis of the prdperties of brown coals from the world largest brown coals basins-Kansk-Achinsk (Russia) and Yallourn (Australia) with respect to the production of alternative liquid hydrocarbon fuel.
Catalytic upgrading 97100325 study with model components
of tarry fuel gases:
a kinetic
Jess A., Chemical Engineering and Pmcessing, Dec. 1996, 35, (6) 487-494. As a contribution to the development of a process for catalytic upgrading of tarry fuel gases, e.g. coke-oven gas, the conversion of naphthalene, benzene and methane on a nickel catalyst in the presence of HZ and Hz0 was studied. The experiments were performed in a tubular flow reactor. The kinetic data were obtained by systematic variation of the reaction conditions. At temperatures of more than 800°C. each hydrocarbon is cracked and converted with HZ0 to CO and HZ. Soot formation does not occur at any temperature. In case of simultaneous conversion of all three hydrocarbons, competitive reactions have to be considered. The rate of chemical reaction on the catalyst is substantially decreased in the presence of HzS. Nevertheless, in a reactor of industrial scale, HtS has only slight influence. The catalyst would be applied with a particle drameter of I9 mm (experiments: I.5 mm), and the overall reaction rate of hydrocarbon conversion is significantly affected by gas film diffusion.
97100326 Characteristics in a drop tube reactor
of entrained
flow coal gasification
Lee, J. G. et al., Reel, 1996, 75, (9), 1035-1042. The effects of reaction temperature, oxygen/coal and steam/coal ratios and residence time on coal gasification performance in entrained flow were determined by means of a drop tube reactor. The hydrogen/carbon monoxide molar ratio decreases with increasing reaction temperature and the hydrogen/carbon monoxide content of the product gas exhibit a maximum around the ash fusion temperature. With increasing oxygen content, carbon conversion increases and the rate of production of hydrogen/carbon monoxide increases initially to a maximum value. The optimum oxygen/coal ratio is in the range 0.6-0.9 for different coals.
97100327 Characterization of organic and inorganic by-products from field-scale gasification/incinerator for waste tires Koo, J. and Kim, S., Toxicol. Environ. Chem., 1995, 52, (l-4) 203-213. The objective of this study is to establish experitintally the distribution of gasification products such as condensed and noncondensed fuel, inorganic gas, and residue generated from the field-scale gasification incinerator connected directly with a batch type gasifier of waste tires. In the gasification reactor injecting air, the reaction takes place in two steps, the first one being true pyrolysis and the second one being the gasification step. In the field-scale gasification process, a greater portion of oil (200-300 mg oil/m’) is produced at the beginning of the gasification process, and it is controlled by the initial pyrolysis reaction. A greater amount of noncondensed fuel is produced in the middle of the gasification process, The hydrocarbon distribution of the condensable product consists of various aromatic compounds such as naphthalene, I-limonene, methylbenzene, and so on. The zinc content of the ash is the highest, with the exception of iron, and Si, Ai, Ca, Cu, Ni, S, and Cd are also noted. Toxic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) and other organics are contained in the bottom and fly ash.
97100328
CO2 gasification
of iron loaded carbon
Tanaka, S. et al., Sekitan Kagaku Kaigi Happyo Ronhunshu, 1993, 30, hl70. (In Japanese) Carbon dioxide gasification of iron-loaded Yallourn coal, carbon black, and active carbon was carried out in a thermobalance. The sample was heated to 800°C under argon and then gasified with carbon dioxide. When the sample was treated at 780 to approximately 800°C with carbon monoxide for I20 s, a rapid weight decrease was observed for selected samples. Such rapid gasification was attributed to the highly dispersed state of iron on the carbon species.
97100329 Continuous content of carbonaceous
measurement of change in oxygen materials during the gasification
Miura, K. et al., Sekitart Kagaku Kaigi Happyo Ror~hunshu, 1993. 30, 63-66. (In Japanese) Oxygen uptake on carbon materials during gasification was estimated by continuously measuring the atmospheric change and the composition of the gaseous products (using a sensitive thermobalance and a mass spectrometer). Step response experiments for 1802 injections were also performed to examine transient behaviour during gasification. The role of adsorbed oxygen in the gasification mechanism was examinedd based on these experiments.
24
Fuel and Energy Abstracts
January 1997
97100330
Development
of materials
for coal gasification
Kihara, S., Fushoku Boshoku Bumon Iinkai Shir)?o (Nippon Zairyo Gakkai), 1996, 192, 34-45. (In Japanese) This paper examines the various corrosion testing results of the materials for coal gasification. Sulfide-based corrosion occurs during high-temperature operation of the coal gasification approach.
97100331 temperature
Differences in ash deposit in an entrained-bed gasifier
form
caused
by wall
Sekitan Kagaku Kaigi Happy0 Rordw~rhtr, 1994. 31. 4XKoyama, S. et al., 51. (In Japanese) Laborary scale apparatus equipped with the wall temperature control device was used to study the adhesion and the deposition behaviour of coal ash on the gasifier wall. The ash melting temperature and the sintering temperature seemed to influence the adhesion force and the deposit form considerably. When wall temperature was below sintering temperature, the deposit was powder-ash with very weak adhesion. Between melting temperature and sintering temperature, the deposit was sintered-lump with strong adhesion. At nearly melting temperature, solid-slag was formed. It could be detached by mechanical action.
97100332 gasification
The diffusion-reaction of coal char particles
system of high temperature
Sekitan Kagaku Kotgi Happy0 Ronhttmhu, 1993. 30, Lin, S. and Horio, M., 55-58. (In Japanese) In this study the diffusion-reaction systems of high temperature gasification in coal char particles were investigated experimentally. Results were analysed taking in to account the effectiveness factors to obtain the gasification rate constants free from mass transfer resistance.
97100333 Dynamics of surface bon gasification with oxygen
oxygen
complex
during
car-
Sekitan Kagaku Kaigi Happyo Rottt+n.shu, 1994, 3 I, 36Zhuang, Q. et al, 39. (In Japanese) Transient kinetics was used to study the dynamic behaviour of surface oxygen complexes formed during the gasification of carbon with isotopically labelled oxygen. The surface oxygen complexes after the gasification were analysed with temperature programmed desorption. A mechanism has been proposed from the present study, together with a former study on the chemical form of surface complexes. It is proved that combination of techniques, such as TPD, TK, DRIFT and isotope labelling could be a powerful means to clarify the mechanism of carbon gasification with oxygen.
97100334 gasification
Effect of heat treatment reactivity
temperature
on coal char
Morishita. K. et al., Sekitan Kagaku Kaigi Happy0 Ronhumhu, 1095, 32, 228-231. (In Japanese) Characterizes the physical and chemical properties of chars obtained from different rank coals by oxygen gasification, TPD technique, and BET method.
97100335 The effect of mineral matter and pyrolysis conditions on the gasification of Greek lignite by carbon dioxide Samaras, P. et al., Fuel, 1996, 75, (9), 1108-l 114. Experiments conducted for this article involved the production of specimens with different mineral matter contents from Greek lignite using various acid treatment conditions. Ash content and chemical composition of mineral matter depended on the type of acid used and the sequence of the treatment stages. Gasification rates of coals were investigated by thermogravimetric analysis in a carbon dioxide atmosphere in the temperature range 700-900°C. Details the combined effects of components and carbonization conditions.
97100336 gasification
Effects of gasifying agent rate of Taiheiyo coal char
composition
on
the
Tsuji, T. et al., Kagaku Kogaku Ronhunshu, 1996, 22, (4). 794-800. (In Japanese) This paper looks at the steam gasification of Taiheiyo coal char. This was carried out in order to determine gasification kinetics taking account of the concentration dependence of coexisting gases of Hz, CO?. CO and OZ. Gasification tests were conducted with five different gas mixtures as gasifying agents at atmospheric pressure and over a temperature range of 1073 to 1273 K using a differential fixed bed reactor. The reaction rate equation was expressed by such functions as temperature, partial pressure of the gases, changes of pore structure and surface area of char and unconverted carbon fraction of the char. The dependence of the gasification rate on the partial pressure of HzO, COr and CO was able to be expressed by Langmuir-Hinshelwood kinetics which accounts for the decrease in the rate due to coexistence of Hz and CO. The partial pressure of CO2 had little effect on the rate in the HaO-CO2 gasification because the reaction rate of HZ0 is greater than COZ. The reaction rate of the char with Oa depends on the diffusion coefficient of Oz in the mixed gas. The rate equation based on the shrinking sphere model was in good agreement with the experimental result. The dependence of the steam reaction rate on the unconverted carbon fraction of partially burned char is almost the same as that of the char before burning.