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04273 Development on coal gasifier in IGCC demonstration plant
16
Fuel science and technology (fundamental science, analysis, instrumentation)
were displayed by the pressure and heating rate on tar yields and BTX, PCX and naphthalene contents in oil. Increasing pressure and lowering heating rate enhance the tar yields and result in high yields of BTX and PCX. Compared with hydropyrolysis under the same Hz partial pressure (3 MPa), the tar yield increases by 1.2 times and the yields of BTX, PCX and naphthalene. by about 1.6, 1.3 and 1.6 times, respectively. At the same total pressure (3 MPa), the yields of BTX and naphthalene from the co-pyrolysis are equal to those from hydropyrolysis. Other components in COG (methane, carbon monoxide, etc.) were found to b: significant to th,e pyrolysis behaviour of coal under COG and the Improvement of od qualities. Copyrolysis of coal with coke-oven gas. IV. Influ96lQ4266 ence of CH4 and CO on pyrolysis yields Liao, H. et al. Ranliao Huaxue Xuebao, 1998, 26, (l), 13-17. (In Chinese) Under reactive gases of different contents of H3, CH4, CO, etc., pyrolysis of Xianfeng lignite was investigated, in a 10-g fixed-bed reactor, under the same H2 partial pressure (3MPa) and the final temperature of 650°C with a heating rate of 5”C/min. The tar yields were analysed by a SHIMADZU GC-17A/QP-5000MS. CH4 and CO in the coke-oven gas were found to play important roles in coal pyrolysis. CH4 in coke-oven gas is beneficial for increasing tar yield and for a high content of BTX and naphthalene, but it decreases the total conversion. In coke-oven gas, CO is helpful for increasing the total conversion and tar yield. However, for a high content of PCX, it brings the unwanted production of water from the reaction between CO and Hz. By comparison, CHd plays a more important role than CO for increasing the tar yield and enhancing the quality of tar. Corrosion of T-l 1 syngas cooler tubes in IGCC pilot 98164269 plant Kihara, S. et al. Mater. High Temp., 1997, 14, (4), 429-433. In an IGCC pilot plant which was operated 4700 h for 6.25 year, the wall loss of syngas cooler tubes (T-11) were measured. The corrosion rate is oseudo-linear and the total loss is 3.2 mm maximum. Layers of iron sulfide gnd oxide comprise the scale formed. The corrosion loss is too large for high temperature corrosion only at tube skin temperature of 230-250°C. The syngas cooler was opened to air for the shutdown time of about 59,000 h. Therefore, it is concluded that the downtime corrosion strongly contributed to the loss of tube wall in this test plant. Design of a high-temperature heat exchanger for 96iO4270 integration in a combined gas and steam turbine process with pressurized coal dust firing Neumann, F. Fortschr.-Ber. WI; Reihe 6, 1996, 343, l-215. (In German) In a high-temperature heat exchanger, the hot flue gases are cooled in stages. The heat exchanger includes a mixing chamber for quench cooling of the flue gases by mixing with cold air for solidification and removal of ash particles. The heat exchanger has a regenerative heater for recovery of radiant heat for reheating of the clean flue gases to the feed temperature of the gas turbine. Ceramic materials have been investigated in relation to the construction of the regenerator, particularly silicon-infiltrated SIC. The energy efficiency of process variations in flue gas cooling and cleaning are analysed. Designing solutions for low NO, related water-wall 9ai04271 corrosion Urich, J. A. and Kramer, E. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996), 25-29. Staged combustion is fundamental to all low NO, burner and overfire air retrofits. This is the creation of alternating fuel rich and fuel lean regions. If deep staging is required to achieve NO, limits, significant areas of fuel rich (reducing) conditions can be produced on the waterwalls of the furnace. The increase in reducing conditions can, under the right combination of conditions, lead to an increase in waterwall corrosion. The combination of conditions leading to increased waterwall corrosion at the PSI Gibson station is presented. The cause and effect relationship between the reducing conditions and the waterwall corrosion is explored and points to limiting the reducing atmosphere along the side wall as the best solution The paper presents the results of computational fluid dynamic modelling for the development of a specific design. 98/04272 The development and testing of an air/steam blown entrained flow gasifier fueled with cotton waste and sawdust Joseph, S. et al. Bioenergy ‘96, Proc. Natl. BioenergV Conf.. 7th, 1996, 1, 304-311. Approximately 50 million tons of biomass residue is produced annually in Australia. A recent study, sponsored by the Energy Research and Development Corporation (ERDC), has concluded that there is a potential to generate at least 2000 MW of electricity per year from this waste. Research carried out in 1990 by Biomass Energy Services and Technology Pty (BEST) indicated that gasification power generating equipment with electrical outputs of l-5 MW and installed capital costs of US%1200 per kW could be viable at present electricity prices. Equipment was not commercially available at the target price at that time, so an R&D programme was undertaken to develop gasification equipment suitable for Australian conditions. It appeared that an entrained flow (vortex) gasifier could handle the range of fuels available and could be produced at a commercially viable price. The design is outlined and mathematical modelling of the flow
and the results of the tests undertaken are presented in this paper. An outline of the demonstration programme to be undertaken next year at a cotton gin will be given, along with the preliminary economic analysis, that has been carried out. Development on coal gasifier in IGCC demonstra9alQ4273 tion plant Kanekom, S. et al. Mitsubishi Juko Giho, 1997, 34, (I), 2-5. (In Japanese) Japanese R&D has progressed from the pilot phase to a successful demonstration phase with the 200 t/d IGCC pilot plant. Regarding the air blown two stage entrained flow coal gasification technology, the principle of which was fully verified at the Nakoso pilot plant, Mitsubishi Heavy Industries Ltd. has been conducting the elemental study for the scaling-up to a 2000 t/d class demonstration gasifier from 1995. The crucial test results for the basic design of the demonstration gasifier has being obtained. This also applies to fundamental technologies such as the evaluation method on coal and ash property and high density particle handling. These results enable the enhancement of economy, reliability and performance of the demonstration gasifier in comparison with the 200 t/d gasifier. Effects of unfavorable thermodynamics on reactive gal04274 distillation column design Okasinski, M. J. and Doherty, M. F. Inst. Chem. Eng. Symp. Ser., 1997, 142, (Distillation and Absorption ‘97, 2), 695-704. In chemical systems which exhibit ‘unfavourable’ thermodynamic such as azeotropes and/or a small reaction equilibrium constant, reactive distillation technology is often overlooked as a viable process alternative. However, a better understanding of these effects on reactive system phase behaviour and column design yields insight into when reactive distillation can offer competitive process alternatives. The first example, which considers a mixture with an azeotrope between the reactant and one of the products, shows that the azeotrope can be ‘broken’ by reactive distillation without using additional entrainers, solvents, etc. In the second example, it is demonstrated that reactive distillation provides a viable process alternative to conventional technology, even when the reactive equilibrium constant is small (51). 98104275 Electrostatic precipitation Toshiaki, M. Purozuma, Kaku Yugo Gakkaishi, 1998, 74, (2), 128-133. (In Japanese) The basic principle, structure and characteristics of an electrostatic precipitator are described here. The latest technologies for high resistivity dust collection, such as pulse energization, moving electrode type electrostatic precipitator and new gas treatment systems for coal fired boilers are also reviewed. 98IO4276 Energy recovery system for the release of natural gas Bollinger, F. Gaz d’Aujourd’hui, 1998, 122, (3), 131-!35. (In French) This energy recovery system was presented in a poster presentation in the 114th Gas Congress at Toulouse. This paper reviews and develops the description of the development of the different components of the system. 98104277 Enhancing burner diagnostics and control with chaos-based signal analysis techniques Fuller, T. A. et al. HTD, 1996, 335, (Proceedings of the ASME Heat Transfer Division, 1996, 4), 281-291. To improve plant efficiency and reduce emissions and driven by economic pressures and government emissions regulations, the electric power industry is moving toward tighteI control of boilers. For this, better diagnostic tools that discriminate short-timt-scale flame patterns and correlations between those flame patterns and overall performance, are essential. Our research indicates that improved discrimination of shorttime-scale patterns in boilers can be achieved by combining traditional data analysis techniques and chaotic time series analysis. Suggested analysis tools and data acquisition procedures are described, with example results for measurements from a low-NO, pulverized coal combustor. 98/04276 Exergy diagrams for nitrogen on ITS-90 Rani, R. R. and Srinivasan, K. ht. J. Energy Res., 1997, 21, (11), 10531059. In the range 0.1-10 MPa and from the triple point to 500 K, the exergyenthalpy and temperature-exergy diagrams have been generated. On the international temperature scale (ITS-90), these diagrams have been generated using a calculation scheme proposed by R. T. Jacobsen ef a/.( 1986). The authors have developed a computer program for calculating the thermodynamic properties of nitrogen, including exergy as a property, from the triple point to 800 K at pressures up to 30 MPa. These exergy based thermodynamic property charts can be useful in the energy efficiency analyses of cryo-refrigeration cycles involving nitrogen as a working medium. A sample analysis is included. 98lo4279 The fast-response flame ionization detector Cheng, W. K. et al. Prog. Energy Combust. Sci., 1998, 24, (2), 89-124. In internal combustion engines, the fast-response flame ionization detector has become a widely used instrument for time-resolved hydrocarbon measurements. The characteristics of and working experience with the instrument are reviewed. In particular, the sampling system and its
Fuel and Energy Abstracts
September
1996
397
Fuel science and technology (fundamental science, analysis, instrumentation)
were displayed by the pressure and heating rate on tar yields and BTX, PCX and naphthalene contents in oil. Increasing pressure and lowering heating rate enhance the tar yields and result in high yields of BTX and PCX. Compared with hydropyrolysis under the same Hz partial pressure (3 MPa), the tar yield increases by 1.2 times and the yields of BTX, PCX and naphthalene. by about 1.6, 1.3 and 1.6 times, respectively. At the same total pressure (3 MPa), the yields of BTX and naphthalene from the co-pyrolysis are equal to those from hydropyrolysis. Other components in COG (methane, carbon monoxide, etc.) were found to b: significant to th,e pyrolysis behaviour of coal under COG and the Improvement of od qualities. Copyrolysis of coal with coke-oven gas. IV. Influ96lQ4266 ence of CH4 and CO on pyrolysis yields Liao, H. et al. Ranliao Huaxue Xuebao, 1998, 26, (l), 13-17. (In Chinese) Under reactive gases of different contents of H3, CH4, CO, etc., pyrolysis of Xianfeng lignite was investigated, in a 10-g fixed-bed reactor, under the same H2 partial pressure (3MPa) and the final temperature of 650°C with a heating rate of 5”C/min. The tar yields were analysed by a SHIMADZU GC-17A/QP-5000MS. CH4 and CO in the coke-oven gas were found to play important roles in coal pyrolysis. CH4 in coke-oven gas is beneficial for increasing tar yield and for a high content of BTX and naphthalene, but it decreases the total conversion. In coke-oven gas, CO is helpful for increasing the total conversion and tar yield. However, for a high content of PCX, it brings the unwanted production of water from the reaction between CO and Hz. By comparison, CHd plays a more important role than CO for increasing the tar yield and enhancing the quality of tar. Corrosion of T-l 1 syngas cooler tubes in IGCC pilot 98164269 plant Kihara, S. et al. Mater. High Temp., 1997, 14, (4), 429-433. In an IGCC pilot plant which was operated 4700 h for 6.25 year, the wall loss of syngas cooler tubes (T-11) were measured. The corrosion rate is oseudo-linear and the total loss is 3.2 mm maximum. Layers of iron sulfide gnd oxide comprise the scale formed. The corrosion loss is too large for high temperature corrosion only at tube skin temperature of 230-250°C. The syngas cooler was opened to air for the shutdown time of about 59,000 h. Therefore, it is concluded that the downtime corrosion strongly contributed to the loss of tube wall in this test plant. Design of a high-temperature heat exchanger for 96iO4270 integration in a combined gas and steam turbine process with pressurized coal dust firing Neumann, F. Fortschr.-Ber. WI; Reihe 6, 1996, 343, l-215. (In German) In a high-temperature heat exchanger, the hot flue gases are cooled in stages. The heat exchanger includes a mixing chamber for quench cooling of the flue gases by mixing with cold air for solidification and removal of ash particles. The heat exchanger has a regenerative heater for recovery of radiant heat for reheating of the clean flue gases to the feed temperature of the gas turbine. Ceramic materials have been investigated in relation to the construction of the regenerator, particularly silicon-infiltrated SIC. The energy efficiency of process variations in flue gas cooling and cleaning are analysed. Designing solutions for low NO, related water-wall 9ai04271 corrosion Urich, J. A. and Kramer, E. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996), 25-29. Staged combustion is fundamental to all low NO, burner and overfire air retrofits. This is the creation of alternating fuel rich and fuel lean regions. If deep staging is required to achieve NO, limits, significant areas of fuel rich (reducing) conditions can be produced on the waterwalls of the furnace. The increase in reducing conditions can, under the right combination of conditions, lead to an increase in waterwall corrosion. The combination of conditions leading to increased waterwall corrosion at the PSI Gibson station is presented. The cause and effect relationship between the reducing conditions and the waterwall corrosion is explored and points to limiting the reducing atmosphere along the side wall as the best solution The paper presents the results of computational fluid dynamic modelling for the development of a specific design. 98/04272 The development and testing of an air/steam blown entrained flow gasifier fueled with cotton waste and sawdust Joseph, S. et al. Bioenergy ‘96, Proc. Natl. BioenergV Conf.. 7th, 1996, 1, 304-311. Approximately 50 million tons of biomass residue is produced annually in Australia. A recent study, sponsored by the Energy Research and Development Corporation (ERDC), has concluded that there is a potential to generate at least 2000 MW of electricity per year from this waste. Research carried out in 1990 by Biomass Energy Services and Technology Pty (BEST) indicated that gasification power generating equipment with electrical outputs of l-5 MW and installed capital costs of US%1200 per kW could be viable at present electricity prices. Equipment was not commercially available at the target price at that time, so an R&D programme was undertaken to develop gasification equipment suitable for Australian conditions. It appeared that an entrained flow (vortex) gasifier could handle the range of fuels available and could be produced at a commercially viable price. The design is outlined and mathematical modelling of the flow
and the results of the tests undertaken are presented in this paper. An outline of the demonstration programme to be undertaken next year at a cotton gin will be given, along with the preliminary economic analysis, that has been carried out. Development on coal gasifier in IGCC demonstra9alQ4273 tion plant Kanekom, S. et al. Mitsubishi Juko Giho, 1997, 34, (I), 2-5. (In Japanese) Japanese R&D has progressed from the pilot phase to a successful demonstration phase with the 200 t/d IGCC pilot plant. Regarding the air blown two stage entrained flow coal gasification technology, the principle of which was fully verified at the Nakoso pilot plant, Mitsubishi Heavy Industries Ltd. has been conducting the elemental study for the scaling-up to a 2000 t/d class demonstration gasifier from 1995. The crucial test results for the basic design of the demonstration gasifier has being obtained. This also applies to fundamental technologies such as the evaluation method on coal and ash property and high density particle handling. These results enable the enhancement of economy, reliability and performance of the demonstration gasifier in comparison with the 200 t/d gasifier. Effects of unfavorable thermodynamics on reactive gal04274 distillation column design Okasinski, M. J. and Doherty, M. F. Inst. Chem. Eng. Symp. Ser., 1997, 142, (Distillation and Absorption ‘97, 2), 695-704. In chemical systems which exhibit ‘unfavourable’ thermodynamic such as azeotropes and/or a small reaction equilibrium constant, reactive distillation technology is often overlooked as a viable process alternative. However, a better understanding of these effects on reactive system phase behaviour and column design yields insight into when reactive distillation can offer competitive process alternatives. The first example, which considers a mixture with an azeotrope between the reactant and one of the products, shows that the azeotrope can be ‘broken’ by reactive distillation without using additional entrainers, solvents, etc. In the second example, it is demonstrated that reactive distillation provides a viable process alternative to conventional technology, even when the reactive equilibrium constant is small (51). 98104275 Electrostatic precipitation Toshiaki, M. Purozuma, Kaku Yugo Gakkaishi, 1998, 74, (2), 128-133. (In Japanese) The basic principle, structure and characteristics of an electrostatic precipitator are described here. The latest technologies for high resistivity dust collection, such as pulse energization, moving electrode type electrostatic precipitator and new gas treatment systems for coal fired boilers are also reviewed. 98IO4276 Energy recovery system for the release of natural gas Bollinger, F. Gaz d’Aujourd’hui, 1998, 122, (3), 131-!35. (In French) This energy recovery system was presented in a poster presentation in the 114th Gas Congress at Toulouse. This paper reviews and develops the description of the development of the different components of the system. 98104277 Enhancing burner diagnostics and control with chaos-based signal analysis techniques Fuller, T. A. et al. HTD, 1996, 335, (Proceedings of the ASME Heat Transfer Division, 1996, 4), 281-291. To improve plant efficiency and reduce emissions and driven by economic pressures and government emissions regulations, the electric power industry is moving toward tighteI control of boilers. For this, better diagnostic tools that discriminate short-timt-scale flame patterns and correlations between those flame patterns and overall performance, are essential. Our research indicates that improved discrimination of shorttime-scale patterns in boilers can be achieved by combining traditional data analysis techniques and chaotic time series analysis. Suggested analysis tools and data acquisition procedures are described, with example results for measurements from a low-NO, pulverized coal combustor. 98/04276 Exergy diagrams for nitrogen on ITS-90 Rani, R. R. and Srinivasan, K. ht. J. Energy Res., 1997, 21, (11), 10531059. In the range 0.1-10 MPa and from the triple point to 500 K, the exergyenthalpy and temperature-exergy diagrams have been generated. On the international temperature scale (ITS-90), these diagrams have been generated using a calculation scheme proposed by R. T. Jacobsen ef a/.( 1986). The authors have developed a computer program for calculating the thermodynamic properties of nitrogen, including exergy as a property, from the triple point to 800 K at pressures up to 30 MPa. These exergy based thermodynamic property charts can be useful in the energy efficiency analyses of cryo-refrigeration cycles involving nitrogen as a working medium. A sample analysis is included. 98lo4279 The fast-response flame ionization detector Cheng, W. K. et al. Prog. Energy Combust. Sci., 1998, 24, (2), 89-124. In internal combustion engines, the fast-response flame ionization detector has become a widely used instrument for time-resolved hydrocarbon measurements. The characteristics of and working experience with the instrument are reviewed. In particular, the sampling system and its
Fuel and Energy Abstracts
September
1996
397