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03207 Effect of particle size on hydrogasification of coal in the low heating rate range
03
Gaseous
fuels(derivedgaseous fuels)
convincing evidence, that near equivalent conversions optimization of the freeboard design, nickel catalyst and particle size.
can be obtained by content, bed depth,
00103205 Coal gasification in moving bed reactor with a draft tube Liu, Y. er crl. Chin J Chcn?. Eng.. 1999, 7, (2), 178&181. In this paper, various coal gasification experiments are described. 00/03206 Dynamic modeling and simulation of Shell gasifier Han, Z. er al. Qinghlrrr Dautrr X~frhao, Zfran Ke.wrhun. 1999, 39, (3), I I I114. (In Chinese) The conversing-deduce method is used to obtain the geometry of the Shell gasifier used in the Netherlands Buggenum IGCC power plant. The inner flow pattern of the gasifier is calculated using the injection flow theory, and the inner gasifier is divided into three zones: combustion zone, gasification zone and recirculation zone. Applying the mass, energy and moment balance to each zone, and considering the slag layer, a set of differential and algebraic equation can be derived. Conclusions are drawn by investigating the results of dynamic and static simulation. 00103207 Effect of particle size on hydrogasification of coal in the low heating rate range Porada, S. and Jonas, J. Gosh& Surot~~cami iMiner, 1999, IS, (I). 119-125. (In Polish) The kinetics of the evolution of gas hydrocarbons during the hydrogasification of bituminous coal was studied under a pressure of 2.5 MPa and a heating rate of 3 K/min. Diffusion processes within grains were found to be of minimal importance when under the applied conditions. 00103208 Effect of sodium and lithium carbonate catalysts on the rate of steam gasification of low-temperature lignite coke Durusoy, T. Energy Sources, 1999, 21, (7), 621-627. A low-rank lignite coke was impregnated by two different catalysts (Na2C03, Li2C03) to investigate the effects of catalyst type at different reaction temperatures (600-700°C) on the rate of steam gasification in a fixed reactor. Total conversion sharply increased with increasing gasification time and with the use of Na2C02 and LizC03. The catalytic activities under identical experimental conditions were ranked as Na*CO? > Li&03. Activation energies and frequency factors of the catalytic reactions were deduced through a kinetic model and compared with non-catalytic steam gasification reactions. Catalytic reactions yielded much smaller values than those of the non-catalytic reactions. Furthermore, it was also observed that the reaction temperature was the main factor in the conversion rate. 00103209 Effect of the intraparticle mass transport limitations on temperature profiles and catalytic performance of the reverse-flow reactor for the partial oxidation of methane to synthesis gas Gosiewski, K. et (II. Chem. Eng. Scl., 1999, 54, (20), 4589-4602. This paper presents a mathematical model of the reverse-flow reactor for the catalytic conversion of methane to synthesis gas. The model contains eight partial differential equations and six algebraic equations. The performed analysis and the literature data suggest a considerable influence of the diffusional resistance in the catalyst pellet upon the actual rate of reactions occurring in the process. A simple approximate procedure is developed for the estimation of the effectiveness factor of the reactions, which enables the resistance due to internal diffusion to be taken into account at any point of the reactor without resorting to numerical integration of the diffusion equations in the pellet. A comparison is presented between the effectiveness factor rl obtained via the integration of the diffusion equations and that calculated using the linearized reaction rate equations. To solve the model of the whole reactor the software package PDEXlM is used which makes it possible to continuously adapt the temporal and spatial steps. The package adapts the local density of the grid in such a way that an assumed value of the error of computations can be obtained. Results of simulations for the reverse-flow reactor, carried out for q varying in the reactor are compared with those done at an arbitrarily selected constant value of rl. The possibility of lowering the maximum temperature in the catalytic bed by altering the pellet size and adding Hz0 into the feed gas is also analysed. 00103210 Fischer-Tropsch synthesis catalyst rejuvenation Koveal, R. J. and Alexion, D. G. US. US 5,929,126 (Cl. 518-709; CO7C271 00), 27 Jul 1999, Appl. 16,178, 30 Jan 1998. 9. A synthesis gas conversion process produces a gas containing ammonia and hydrogen cyanide. It forms hydrocarbons by reacting the hydrogen and carbon monoxide in the gas in the presence of a hydrocarbon synthesis catalyst and also reversibly deactivates the catalyst due to the presence of the ammonia and hydrogen cyanide in the gas. The catalyst is rejuvenated with a gas comprising hydrogen and produces an ammonia containing rejuvenation off-gas. The ammonia is dissolved out of the off-gas with water and then stripped out of the water with the hydrocarbon feed to the synthesis gas generator and into the generator. 00/03211 Gas cleaning for biomass gasification Hasler, P. H. er crl. VTT. S.vmp., 1999, 192, 371-382.
362
Fuel and Energy Abstracts
November 2000
A crucial step in the gasification of biomass for power production, is the cleaning of the gas. In the present Investigation, gas-cleaning systems are evaluated for IC applications from cocurrent fixed bed gasifiers and for methanol synthesis from CFB gasifiers. For particle and tar removal, wet and dry gas cleaning systems are considered. In both applications, condensates are produced since IC engines are fuelled with cold gas and gas quality requirements for methanol synthesis ask for additional wet gas the tar and particle collection cleaning. In the present investigation, efficiencies have been detected in a fabric filter, a sand bed filter, a rotational wash tower and a rotational particle separator in different test runs with fixed bed gasifiers. Furthermore data from literature for catalytic tar crackers, venturi scrubbers, a fabric filter, a rotational atomizer, and a wet electrostatic precipitator (ESP) are given. For two systems, data on the removal of gaseous Impurities (NHI, HCI and HzS) are presented. Based on the presented gas cleaning efficiencies and the investment cost, an assessment of gas cleaning systems is made for IC applications from cocurrent gasifiers. In addition, a gas cleaning system for methanol synthesis from CFB gasification is presented. The results demonstrate that the postulated gas quality requirements for IC engines and syngas can not be achieved safely with state-of-the-art gas cleaning techniques and that 90% particle removal is easier to achieve than 90% tar removal. One of the key issues for a successful application of biomass derived producer gas is the removal of tar, further development is required in this area, because, none of the investigated gas cleaning systems can securely meet a reduction in tar that exceeds 90%, except for the catalytic tar crackers. 00103212 Gas conversion, using hydrogen from synthesis gas and hydroconversion tail gas Degeorge, C. W. c/ crl. PCT Int. Appl. WO 99 40,048 (Cl. CO7C l/04), I2 Aug 1999, US Appl. 21.476, IO Feb 1998. 25. Hydrogen is produced in a gas conversion process including catalytic hydrocarbon synthesis from a synthesis gas comprising a mixture of Hz and CO. This process also upgrades synthesized hydrocarbons by one or more hydroconversion operations which utilize the hydrogen. The hydroconversion also produces a hydrogen rich tail gas which is used in the process for at least one of (i) hydrocarbon synthesis catalyst rejuvenation, (ii) the hydrocarbon synthesis, and (iii) hydrogen production. The tail gas can be used to hydrodesulfurize sulfur-containing hydrocarbon liquids recovered from natural gas used to form synthesis gas. The hydrogen production is accomplished by physical separation such as pressure-swing adsorption, and not necessarily by chemical means such as water-gas shift reaction. 00/03213 Gasification and pyrolysis of low-grade condensed fuels Manelis, G. B. PI rrl. PCT Int. Appl. WO 99 37,739 (Cl. ClOJ3114). 29 Jul 1999, RU Appl. 98.101.335. 22 Jan 1998. 18. Pyrolysis and gasification treat low-grade condensed fuels, primarily highly humid fuels (e.g. municipal refuse, biomass, sludges, oil slurries, brown coal) to produce liquid hydrocarbons and fuel gases which are used for energy generation. The method can be used for environmentally friendly processing and disposal of poorly combustible wastes. The fuel is charged in a gasifier shaft kiln reactor, possibly together with a solid incombustible non-melting material, counter-currently with an oxygen-containing gasifying agent. Smoke gases (steam-containing flue gases) are added to or used as the gasifying agent. The maximum temperature in the reactor is controlled at EOO-1300°C by a variation of the fraction of the smoke gas in the gasifying agent. 00103214 Gasification apparatus Akiyama, T. CI trl. Jpn. Kokai Tokkyo Koho JP 1I 172,263 [99 172,263] (Cl. ClOJ3/46), 29 Jun 1999. Appl. 1997/342.371, I2 Dee 1997. 6. (In Japanese) The title apparatus comprises a reaction chamber for reacting coal and an oxidizing agent, a slag recovery chamber under the reaction chamber for recovering the melting slag generated from the reaction chamber, a slag discharge outlet between the reaction chamber and recovery chamber and burners for heating the slag dropped from the discharge outlet. It is characterized in that the combustion gas is injected to the recovery chamber through the burners at a direction for offsetting the rotary flow in the reaction chamber. 00/03215 Gasification of solid fuels for separation of volatile constituents and coke Wolf, B. Ger. Offen. DE 19,807,98X (Cl. ClOB53/00), 2 Sep 1999, Appl. 19,807,988, 26 Feb 1998. 6. (In German) The recovery of fuel gases and other volatile constituents of solid fuels such as coal, refuse and organic wastes, e.g. wood chips, takes place without using an external heat supply. The solid fuels are subjected to partial oxidation gasification using 02 in air or in H20/COz mixtures as the gasifying agent at 350-800” and I-100 bar, forming coke and tar-containing fuel gases. The gasification is performed in hot moving coke beds or streams under mechanical or pneumatic conveying with recirculation of the gasifying agent. There are separate discharges for the coke and the gases. 00103216 Gasification of two biomass fuels in bubbling fluidired bed Miccio, F. e! crl. Proc. In!. Conf. Fluid. Bed Co&us/., 1999, 108-120. An experimental study of the gasification of two biomass fuels, beech wood and a dry granular sewage sludge from the Swiss Combi process, has been carried out in a laboratory scale ABFB facility, operated at steady state.
Gaseous
fuels(derivedgaseous fuels)
convincing evidence, that near equivalent conversions optimization of the freeboard design, nickel catalyst and particle size.
can be obtained by content, bed depth,
00103205 Coal gasification in moving bed reactor with a draft tube Liu, Y. er crl. Chin J Chcn?. Eng.. 1999, 7, (2), 178&181. In this paper, various coal gasification experiments are described. 00/03206 Dynamic modeling and simulation of Shell gasifier Han, Z. er al. Qinghlrrr Dautrr X~frhao, Zfran Ke.wrhun. 1999, 39, (3), I I I114. (In Chinese) The conversing-deduce method is used to obtain the geometry of the Shell gasifier used in the Netherlands Buggenum IGCC power plant. The inner flow pattern of the gasifier is calculated using the injection flow theory, and the inner gasifier is divided into three zones: combustion zone, gasification zone and recirculation zone. Applying the mass, energy and moment balance to each zone, and considering the slag layer, a set of differential and algebraic equation can be derived. Conclusions are drawn by investigating the results of dynamic and static simulation. 00103207 Effect of particle size on hydrogasification of coal in the low heating rate range Porada, S. and Jonas, J. Gosh& Surot~~cami iMiner, 1999, IS, (I). 119-125. (In Polish) The kinetics of the evolution of gas hydrocarbons during the hydrogasification of bituminous coal was studied under a pressure of 2.5 MPa and a heating rate of 3 K/min. Diffusion processes within grains were found to be of minimal importance when under the applied conditions. 00103208 Effect of sodium and lithium carbonate catalysts on the rate of steam gasification of low-temperature lignite coke Durusoy, T. Energy Sources, 1999, 21, (7), 621-627. A low-rank lignite coke was impregnated by two different catalysts (Na2C03, Li2C03) to investigate the effects of catalyst type at different reaction temperatures (600-700°C) on the rate of steam gasification in a fixed reactor. Total conversion sharply increased with increasing gasification time and with the use of Na2C02 and LizC03. The catalytic activities under identical experimental conditions were ranked as Na*CO? > Li&03. Activation energies and frequency factors of the catalytic reactions were deduced through a kinetic model and compared with non-catalytic steam gasification reactions. Catalytic reactions yielded much smaller values than those of the non-catalytic reactions. Furthermore, it was also observed that the reaction temperature was the main factor in the conversion rate. 00103209 Effect of the intraparticle mass transport limitations on temperature profiles and catalytic performance of the reverse-flow reactor for the partial oxidation of methane to synthesis gas Gosiewski, K. et (II. Chem. Eng. Scl., 1999, 54, (20), 4589-4602. This paper presents a mathematical model of the reverse-flow reactor for the catalytic conversion of methane to synthesis gas. The model contains eight partial differential equations and six algebraic equations. The performed analysis and the literature data suggest a considerable influence of the diffusional resistance in the catalyst pellet upon the actual rate of reactions occurring in the process. A simple approximate procedure is developed for the estimation of the effectiveness factor of the reactions, which enables the resistance due to internal diffusion to be taken into account at any point of the reactor without resorting to numerical integration of the diffusion equations in the pellet. A comparison is presented between the effectiveness factor rl obtained via the integration of the diffusion equations and that calculated using the linearized reaction rate equations. To solve the model of the whole reactor the software package PDEXlM is used which makes it possible to continuously adapt the temporal and spatial steps. The package adapts the local density of the grid in such a way that an assumed value of the error of computations can be obtained. Results of simulations for the reverse-flow reactor, carried out for q varying in the reactor are compared with those done at an arbitrarily selected constant value of rl. The possibility of lowering the maximum temperature in the catalytic bed by altering the pellet size and adding Hz0 into the feed gas is also analysed. 00103210 Fischer-Tropsch synthesis catalyst rejuvenation Koveal, R. J. and Alexion, D. G. US. US 5,929,126 (Cl. 518-709; CO7C271 00), 27 Jul 1999, Appl. 16,178, 30 Jan 1998. 9. A synthesis gas conversion process produces a gas containing ammonia and hydrogen cyanide. It forms hydrocarbons by reacting the hydrogen and carbon monoxide in the gas in the presence of a hydrocarbon synthesis catalyst and also reversibly deactivates the catalyst due to the presence of the ammonia and hydrogen cyanide in the gas. The catalyst is rejuvenated with a gas comprising hydrogen and produces an ammonia containing rejuvenation off-gas. The ammonia is dissolved out of the off-gas with water and then stripped out of the water with the hydrocarbon feed to the synthesis gas generator and into the generator. 00/03211 Gas cleaning for biomass gasification Hasler, P. H. er crl. VTT. S.vmp., 1999, 192, 371-382.
362
Fuel and Energy Abstracts
November 2000
A crucial step in the gasification of biomass for power production, is the cleaning of the gas. In the present Investigation, gas-cleaning systems are evaluated for IC applications from cocurrent fixed bed gasifiers and for methanol synthesis from CFB gasifiers. For particle and tar removal, wet and dry gas cleaning systems are considered. In both applications, condensates are produced since IC engines are fuelled with cold gas and gas quality requirements for methanol synthesis ask for additional wet gas the tar and particle collection cleaning. In the present investigation, efficiencies have been detected in a fabric filter, a sand bed filter, a rotational wash tower and a rotational particle separator in different test runs with fixed bed gasifiers. Furthermore data from literature for catalytic tar crackers, venturi scrubbers, a fabric filter, a rotational atomizer, and a wet electrostatic precipitator (ESP) are given. For two systems, data on the removal of gaseous Impurities (NHI, HCI and HzS) are presented. Based on the presented gas cleaning efficiencies and the investment cost, an assessment of gas cleaning systems is made for IC applications from cocurrent gasifiers. In addition, a gas cleaning system for methanol synthesis from CFB gasification is presented. The results demonstrate that the postulated gas quality requirements for IC engines and syngas can not be achieved safely with state-of-the-art gas cleaning techniques and that 90% particle removal is easier to achieve than 90% tar removal. One of the key issues for a successful application of biomass derived producer gas is the removal of tar, further development is required in this area, because, none of the investigated gas cleaning systems can securely meet a reduction in tar that exceeds 90%, except for the catalytic tar crackers. 00103212 Gas conversion, using hydrogen from synthesis gas and hydroconversion tail gas Degeorge, C. W. c/ crl. PCT Int. Appl. WO 99 40,048 (Cl. CO7C l/04), I2 Aug 1999, US Appl. 21.476, IO Feb 1998. 25. Hydrogen is produced in a gas conversion process including catalytic hydrocarbon synthesis from a synthesis gas comprising a mixture of Hz and CO. This process also upgrades synthesized hydrocarbons by one or more hydroconversion operations which utilize the hydrogen. The hydroconversion also produces a hydrogen rich tail gas which is used in the process for at least one of (i) hydrocarbon synthesis catalyst rejuvenation, (ii) the hydrocarbon synthesis, and (iii) hydrogen production. The tail gas can be used to hydrodesulfurize sulfur-containing hydrocarbon liquids recovered from natural gas used to form synthesis gas. The hydrogen production is accomplished by physical separation such as pressure-swing adsorption, and not necessarily by chemical means such as water-gas shift reaction. 00/03213 Gasification and pyrolysis of low-grade condensed fuels Manelis, G. B. PI rrl. PCT Int. Appl. WO 99 37,739 (Cl. ClOJ3114). 29 Jul 1999, RU Appl. 98.101.335. 22 Jan 1998. 18. Pyrolysis and gasification treat low-grade condensed fuels, primarily highly humid fuels (e.g. municipal refuse, biomass, sludges, oil slurries, brown coal) to produce liquid hydrocarbons and fuel gases which are used for energy generation. The method can be used for environmentally friendly processing and disposal of poorly combustible wastes. The fuel is charged in a gasifier shaft kiln reactor, possibly together with a solid incombustible non-melting material, counter-currently with an oxygen-containing gasifying agent. Smoke gases (steam-containing flue gases) are added to or used as the gasifying agent. The maximum temperature in the reactor is controlled at EOO-1300°C by a variation of the fraction of the smoke gas in the gasifying agent. 00103214 Gasification apparatus Akiyama, T. CI trl. Jpn. Kokai Tokkyo Koho JP 1I 172,263 [99 172,263] (Cl. ClOJ3/46), 29 Jun 1999. Appl. 1997/342.371, I2 Dee 1997. 6. (In Japanese) The title apparatus comprises a reaction chamber for reacting coal and an oxidizing agent, a slag recovery chamber under the reaction chamber for recovering the melting slag generated from the reaction chamber, a slag discharge outlet between the reaction chamber and recovery chamber and burners for heating the slag dropped from the discharge outlet. It is characterized in that the combustion gas is injected to the recovery chamber through the burners at a direction for offsetting the rotary flow in the reaction chamber. 00/03215 Gasification of solid fuels for separation of volatile constituents and coke Wolf, B. Ger. Offen. DE 19,807,98X (Cl. ClOB53/00), 2 Sep 1999, Appl. 19,807,988, 26 Feb 1998. 6. (In German) The recovery of fuel gases and other volatile constituents of solid fuels such as coal, refuse and organic wastes, e.g. wood chips, takes place without using an external heat supply. The solid fuels are subjected to partial oxidation gasification using 02 in air or in H20/COz mixtures as the gasifying agent at 350-800” and I-100 bar, forming coke and tar-containing fuel gases. The gasification is performed in hot moving coke beds or streams under mechanical or pneumatic conveying with recirculation of the gasifying agent. There are separate discharges for the coke and the gases. 00103216 Gasification of two biomass fuels in bubbling fluidired bed Miccio, F. e! crl. Proc. In!. Conf. Fluid. Bed Co&us/., 1999, 108-120. An experimental study of the gasification of two biomass fuels, beech wood and a dry granular sewage sludge from the Swiss Combi process, has been carried out in a laboratory scale ABFB facility, operated at steady state.