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03748 The current status of the air blown gasification cycle
03 two major stages: combustion-only experiments and combustion-gasification experiments. The combustion-only experiments showed that volatiles were released and burned in the compartment where coal is fed. Volatiles and char combustion were sufficient to maintain the operating temperature of the CFBCG. Solid circulation induced by two sets of v-valve/riser arrangements was crucial, and determined heat-transfer between the two beds and, thus, controlled the reaction rates. The rate of solid circulation, carbon burning rate, and carbon inventory in a bed were indirectly estimated by measuring pressure drop over a bed compartment. Based on information and experience obtained in the combustion-only experiments, the combustion-gasification experiments were performed to study energy transfer from combustor to gasifier, and the quality of the synthesis gas produced. Circulation of hot solids from the combustor was sufficient to support endothermic reactions in the gasifier. High-quality synthesis gas with an Hz/CO ratio of 4 was achieved. While the CFBCG concept has proved to be sound, further development is needed to improve the operation before practical application.
Coal gasification in molten slag to manufacture reducing gas for smelting in blast furnaces
93lQ3742
Vegman, E. F. et al. Russ. RU 2,083,677 (Cl. C21B5/00), 10 Jul 1997, Appl. 95,106,268, 20 Apr 1995. (In Russian). From Izobreteniya 1997, (19) 330. 93lQ3743 Fujimura,
Coal
H.
gasification reactor
et al. Jpn. Kokai Tokkyo Koho JP 10 17,873 [98 17,873] (Cl.
ClOJ3/46),20 Jan 1998, Appl. 96/173,287, 3 Jul 1996, 8 pp. (In Japanese) A coal gasifier for manufacture bed gasifier is described.
of fuel gas, especially suitable for entrained-
Cogasification of birch wood and Daw Mill coal in pressurized fluidized bed reactor
9Qlo3744
Chen, G. et al. Biomass Gasif. Pyrolysis, [Conf.], 1997, 182-190. Edited by Kaltschmitt, M. and Bridgwater, A. V., CPL Press, Newbury, UK. A pressurized fluidized bed reactor was used for an experimental study on the co-gasification of woody biomass and coal in an oxygen-containing atmosphere. The wood used was birch from a Swedish paper mill, and the coal used was Daw Mill coal of UK origin. The operation temperature was 900°C. the pressure was 0.4 MPa and the ratio of coal to wood was varied. The study was mainly focused on possible synergetic effects towards environmental and operative benefits. The char formed was examined, the nitrogen compounds emitted were detected and the tar produced was analysed. The results are given.
Cogasification of solid fuels 9QlQ3745 of the International Joint Green, A. et al. FACT, 1996, 21, (Proceedings Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996), 369-379. Although the use of natural gas over coal and other solid fuels in new electricity generators is favoured by high-efficiency gas turbine-based systems, utility deregulation and more stringent environmental regulations, the solid fuels could nonetheless continue to compete if a low-cost gasifier with low-cost feedstocks can be coupled with a gas turbine system. On-site gasification of coal with other domestic fuels in an indirectly heated gasifier was examined as a strategy to lower the costs of solid fuel systems. In addition to thermal measurement data and molecular models, the gaseous pyrolysis yields suggested the blending of carbonaceous fuels (e.g. coal, coke, or semi-coke) with oxygenated fuels such as biomass, refuse-derived fuel, municipal solid waste or dried sewage sludge. Such solid fuel blending can achieve an optimum balance of volatiles, heating values, and solid resides, with the help of inexpensive catalysts, thus reducing the technical demands upon the gasifier. Such simplifications should lower capital and operating costs of the gasifier. Completeness and development of the oxy en and slurry coal flowrate control system for the Texaco gas Bfication furnace 93iQ3746
Zhan, K. et al. Huagong Zidonghua Ji Yibiao, 1997, 24, (l), 21-25. (In Chinese) Supplied by Texaco, USA, the Texaco water slurry coal pressure gasification production facility was installed and operated in the Lunan Chemical Fertilizer Plant, China. Design targets were met for the monthly targets and the qualified urea production was over 99%. However, work needs to be carried out regarding the completeness and development of the OSCFRCS, such as the scheme for the raw slurry coal and oxygen flowrate control and the existing problems.
Control strategy for an experimental gasification plant and a steam turbine
90103747
bagasse
Hernandez Santana, L. et al. Cenr. Azucar, 1997, 24, (l), 10-19. (In Spanish) In the CETA of the UCLV in Cuba, an experimental plant of bagasse gasification and gas turbine has been developed. According to world trends in this field, the control and measuring system is indispensable in the plant and comprises the central objective of the work. The dynamic model around the operation point was obtained and the variables to be measured and the control loops to be implemented were determined The preliminary adjustment of the regulators was made with the use of MATLAB.
9QJQ3740
Gaseous fuels (derived gaseous fuels)
The current status of the air blown gasification
cycle Dawes, S. G. et al. Combust. Emiss. Control III, 1997, 239-255. Edited by Adams, M., Institute of Energy, London, UK. Clean Coal Technologies (CCTs) are being developed to meet increased primary energy demand, because they promise higher thermal efficiencies, improved environmental performance and lower electricity costs in comparison with existing technologies. The Air Blown Gasification Cycle (ABGC) is a hybrid partial gasification cycle based on a novel, air blown pressurized fluidized bed gasifier (PFBG) coupled to a circulating fluidized bed combustor (CFBC) to burn the residual char from the PFBG. Fuel gas from the PFBG is cleaned and burnt to produce a gas at high temperature and pressure which is expanded through a gas turbine. The gas turbine exhaust gas is used to raise steam and augment the steam cycle associated with the CFBC. The ABGC offers a higher energy conversion efficiency compared with other CCTs and thus generates correspondingly lower specific carbon dioxide emissions. From British Coal’s original ideas of the 1970s through to the present day, the history of the ABGC is summarized. The ABGC is now being developed by an industry led group known as the Clean Coal Power Generation Group. The CCPGG has undertaken research programmes to prove the individual components of the ABGC and has produced a design specification for a 90 MWc prototype integrated plant (PIP).
99lQ3749 Determination of the gasification kinetics of plastics with the aid of an isothermally operating circulating reactor Hornung, U. Fort&r.-Ber. VDI, Reihe 3, 1997, 485, l-170 (In German) The work determined the kinetics and mechanism of thermal degradation of waste plastics.
98lQ3750
Development of integrated coal gasification com-
blned cycle
Yamauchi, Y. Nippon Kikai Gakkaishi, 1998, 101, (952). 218-219. (In Japanese) The characteristics of dry coal-feed and air blowing two-stage spouted bed coal gasification, the performance of 200 t/d furnace and furnace design goals are described.
Evaluation of hydrocarbon fuels as feedstock for manufacture of reducing gases for metallurgy
93lQ3751
Zubilin, I. G. Koks Khim., 1997, (ll), 22-25. (In Russian) Various materials were evaluated as feeds for the manufacture of reducing gases. The results indicate that in the near future the cost-efficient materials for reducing gases for metallurgy will include hydrocarboncontaining gases, with prepared industrial gases as the most promising gases.
99lQ3752 Extraction of lignite with water in sub- and supercritical states
Hu, H. et al. Fuel Process. Technol., 1998, 53, (3), 269-277. Dayan lignite was extracted with water in sub- and supercritical states on a semi-continuous apparatus. The aim of the experiments was to investigate the effect of temperature on extract formation rate, extract yields and product components at different pressures and end temperatures. The maximum extract formation rate, changing with the pressure, is found at temperatures between 400 and 450°C. The extraction yields vary with the conditions; a pressure increase leads to an increase in the conversion and extract yield increase, while an increase of end temperature also increases the conversion, but the increment is mainly gas and light oil. In the extract, the main fraction is preasphaltene and COz is the main gas component.
Feasibility analysis of ternary feed mixtures of methane with oxygen, steam, and carbon dioxide for the productlon of methanol synthesis gas
9QiQ3753
Tjatjopoulos, G. J. and Vasalos, I. A. Ind. Eng. Chem. Res., 1998, 37, (4), 1410-1421. An analysis of the feasibility of ternary feed mixtures of methane with oxygen, water and carbon dioxide in relation to the production of methanol syngas is reported. Stoichiometric constraints are formulated in terms of three parameters characterizing the steam, partial oxidation and carbon dioxide reforming reactions of methane. The equilibrium analysis is conducted using the methanol balance ratio and methane slip fraction $ as explicit design parameters. 9QlQ3754 Fixed bed gasification for electricity generation. Application in Europe
Buhler, R. Biomass Gasif. Pyrolysis, [Conf.], 1997, 117-128. Edited by Kaltschmitt, M. and Bridgwater, A. V., CPL Press, Newbury, UK. If fixed bed gasification is to become a widespread practice, it should be possible to use the main available sources of cheap biomass in the gasification system, possibly without any further pre-treatment than chipping. Counter-current gasifiers are not sensitive to fuel size, but tar reduction with thermal and/or catalytic cracking is necessary. Low tar content gas can be produced with co-current gasifiers, but most of these are sensitive to fuel size, fuel size distribution and moisture content. However, tests with some co-current systems show promising results. A good gasifier on its own is not sufficient for successful engine application; an efficient and cheap gas cleaning system is essential for commercial application. Considerable uncertainty still exists about the maximum allowable tar and
Fuel and Energy Abstracts
September 1999 351
Coal gasification in molten slag to manufacture reducing gas for smelting in blast furnaces
93lQ3742
Vegman, E. F. et al. Russ. RU 2,083,677 (Cl. C21B5/00), 10 Jul 1997, Appl. 95,106,268, 20 Apr 1995. (In Russian). From Izobreteniya 1997, (19) 330. 93lQ3743 Fujimura,
Coal
H.
gasification reactor
et al. Jpn. Kokai Tokkyo Koho JP 10 17,873 [98 17,873] (Cl.
ClOJ3/46),20 Jan 1998, Appl. 96/173,287, 3 Jul 1996, 8 pp. (In Japanese) A coal gasifier for manufacture bed gasifier is described.
of fuel gas, especially suitable for entrained-
Cogasification of birch wood and Daw Mill coal in pressurized fluidized bed reactor
9Qlo3744
Chen, G. et al. Biomass Gasif. Pyrolysis, [Conf.], 1997, 182-190. Edited by Kaltschmitt, M. and Bridgwater, A. V., CPL Press, Newbury, UK. A pressurized fluidized bed reactor was used for an experimental study on the co-gasification of woody biomass and coal in an oxygen-containing atmosphere. The wood used was birch from a Swedish paper mill, and the coal used was Daw Mill coal of UK origin. The operation temperature was 900°C. the pressure was 0.4 MPa and the ratio of coal to wood was varied. The study was mainly focused on possible synergetic effects towards environmental and operative benefits. The char formed was examined, the nitrogen compounds emitted were detected and the tar produced was analysed. The results are given.
Cogasification of solid fuels 9QlQ3745 of the International Joint Green, A. et al. FACT, 1996, 21, (Proceedings Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996), 369-379. Although the use of natural gas over coal and other solid fuels in new electricity generators is favoured by high-efficiency gas turbine-based systems, utility deregulation and more stringent environmental regulations, the solid fuels could nonetheless continue to compete if a low-cost gasifier with low-cost feedstocks can be coupled with a gas turbine system. On-site gasification of coal with other domestic fuels in an indirectly heated gasifier was examined as a strategy to lower the costs of solid fuel systems. In addition to thermal measurement data and molecular models, the gaseous pyrolysis yields suggested the blending of carbonaceous fuels (e.g. coal, coke, or semi-coke) with oxygenated fuels such as biomass, refuse-derived fuel, municipal solid waste or dried sewage sludge. Such solid fuel blending can achieve an optimum balance of volatiles, heating values, and solid resides, with the help of inexpensive catalysts, thus reducing the technical demands upon the gasifier. Such simplifications should lower capital and operating costs of the gasifier. Completeness and development of the oxy en and slurry coal flowrate control system for the Texaco gas Bfication furnace 93iQ3746
Zhan, K. et al. Huagong Zidonghua Ji Yibiao, 1997, 24, (l), 21-25. (In Chinese) Supplied by Texaco, USA, the Texaco water slurry coal pressure gasification production facility was installed and operated in the Lunan Chemical Fertilizer Plant, China. Design targets were met for the monthly targets and the qualified urea production was over 99%. However, work needs to be carried out regarding the completeness and development of the OSCFRCS, such as the scheme for the raw slurry coal and oxygen flowrate control and the existing problems.
Control strategy for an experimental gasification plant and a steam turbine
90103747
bagasse
Hernandez Santana, L. et al. Cenr. Azucar, 1997, 24, (l), 10-19. (In Spanish) In the CETA of the UCLV in Cuba, an experimental plant of bagasse gasification and gas turbine has been developed. According to world trends in this field, the control and measuring system is indispensable in the plant and comprises the central objective of the work. The dynamic model around the operation point was obtained and the variables to be measured and the control loops to be implemented were determined The preliminary adjustment of the regulators was made with the use of MATLAB.
9QJQ3740
Gaseous fuels (derived gaseous fuels)
The current status of the air blown gasification
cycle Dawes, S. G. et al. Combust. Emiss. Control III, 1997, 239-255. Edited by Adams, M., Institute of Energy, London, UK. Clean Coal Technologies (CCTs) are being developed to meet increased primary energy demand, because they promise higher thermal efficiencies, improved environmental performance and lower electricity costs in comparison with existing technologies. The Air Blown Gasification Cycle (ABGC) is a hybrid partial gasification cycle based on a novel, air blown pressurized fluidized bed gasifier (PFBG) coupled to a circulating fluidized bed combustor (CFBC) to burn the residual char from the PFBG. Fuel gas from the PFBG is cleaned and burnt to produce a gas at high temperature and pressure which is expanded through a gas turbine. The gas turbine exhaust gas is used to raise steam and augment the steam cycle associated with the CFBC. The ABGC offers a higher energy conversion efficiency compared with other CCTs and thus generates correspondingly lower specific carbon dioxide emissions. From British Coal’s original ideas of the 1970s through to the present day, the history of the ABGC is summarized. The ABGC is now being developed by an industry led group known as the Clean Coal Power Generation Group. The CCPGG has undertaken research programmes to prove the individual components of the ABGC and has produced a design specification for a 90 MWc prototype integrated plant (PIP).
99lQ3749 Determination of the gasification kinetics of plastics with the aid of an isothermally operating circulating reactor Hornung, U. Fort&r.-Ber. VDI, Reihe 3, 1997, 485, l-170 (In German) The work determined the kinetics and mechanism of thermal degradation of waste plastics.
98lQ3750
Development of integrated coal gasification com-
blned cycle
Yamauchi, Y. Nippon Kikai Gakkaishi, 1998, 101, (952). 218-219. (In Japanese) The characteristics of dry coal-feed and air blowing two-stage spouted bed coal gasification, the performance of 200 t/d furnace and furnace design goals are described.
Evaluation of hydrocarbon fuels as feedstock for manufacture of reducing gases for metallurgy
93lQ3751
Zubilin, I. G. Koks Khim., 1997, (ll), 22-25. (In Russian) Various materials were evaluated as feeds for the manufacture of reducing gases. The results indicate that in the near future the cost-efficient materials for reducing gases for metallurgy will include hydrocarboncontaining gases, with prepared industrial gases as the most promising gases.
99lQ3752 Extraction of lignite with water in sub- and supercritical states
Hu, H. et al. Fuel Process. Technol., 1998, 53, (3), 269-277. Dayan lignite was extracted with water in sub- and supercritical states on a semi-continuous apparatus. The aim of the experiments was to investigate the effect of temperature on extract formation rate, extract yields and product components at different pressures and end temperatures. The maximum extract formation rate, changing with the pressure, is found at temperatures between 400 and 450°C. The extraction yields vary with the conditions; a pressure increase leads to an increase in the conversion and extract yield increase, while an increase of end temperature also increases the conversion, but the increment is mainly gas and light oil. In the extract, the main fraction is preasphaltene and COz is the main gas component.
Feasibility analysis of ternary feed mixtures of methane with oxygen, steam, and carbon dioxide for the productlon of methanol synthesis gas
9QiQ3753
Tjatjopoulos, G. J. and Vasalos, I. A. Ind. Eng. Chem. Res., 1998, 37, (4), 1410-1421. An analysis of the feasibility of ternary feed mixtures of methane with oxygen, water and carbon dioxide in relation to the production of methanol syngas is reported. Stoichiometric constraints are formulated in terms of three parameters characterizing the steam, partial oxidation and carbon dioxide reforming reactions of methane. The equilibrium analysis is conducted using the methanol balance ratio and methane slip fraction $ as explicit design parameters. 9QlQ3754 Fixed bed gasification for electricity generation. Application in Europe
Buhler, R. Biomass Gasif. Pyrolysis, [Conf.], 1997, 117-128. Edited by Kaltschmitt, M. and Bridgwater, A. V., CPL Press, Newbury, UK. If fixed bed gasification is to become a widespread practice, it should be possible to use the main available sources of cheap biomass in the gasification system, possibly without any further pre-treatment than chipping. Counter-current gasifiers are not sensitive to fuel size, but tar reduction with thermal and/or catalytic cracking is necessary. Low tar content gas can be produced with co-current gasifiers, but most of these are sensitive to fuel size, fuel size distribution and moisture content. However, tests with some co-current systems show promising results. A good gasifier on its own is not sufficient for successful engine application; an efficient and cheap gas cleaning system is essential for commercial application. Considerable uncertainty still exists about the maximum allowable tar and
Fuel and Energy Abstracts
September 1999 351