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02083 Shift reactors and physical absorption for low-CO2 emission IGCCs
10 Engines (power generation and propulsion) or oxygen/air mixed gas and a heat exchanger for heat exchanging of the air extracted with the nitrogen separated from the oxygen-manufacturing equipment and supplying the nitrogen after heat exchange with the combustible gas to the gas-turbine combustor.
W/O2077
Gasification power plant
Fukuhara, K. Jpn. Kokai Tokkyo Koho JP I I 116.975 [9Y 1lh.Y7Sj (Cl. ClOK3/00), 27 Apr 1999, Appl. 97/284,X51, 17 Ott 1997. 7. (In Japanese) Gasification power plants that also contain a gas refining apparatus, obtain their gas supply from a gasifier. The gas turbine uses gas from the gas refining apparatus as fuel. A partial combustion device is positioned on the supply path from the gasifier to the gas refining apparatus, or on a parallel bypass path, it is arranged there to lower the oxygen concentration in gas.
00/02078 Mathematical model of coke-carried-heat gasification coal-fired combined cycle Zhao, L. and Xu. X. Gorr,gc.hPri,g&vI,I~/; X&tro. 1999. 20, ( I ). 26.-29. (In Chinese) Coal-fired combined cycles that demonstrate high efficiency and low pollution combustion technology have developed extremely quickly in recent years. In 1992 a novel combined cycle system was put forward by the thermal engineering department of Tsinghua University. The improved system type is now named coke-carried-heat gasification coal-fired combined cycle, in which the gasification chamber was moved from inside the boiler to the outside as a separate gasifier and the coke is used as the gasification heat source. This paper adopted cell model and modular method, in order to develop a mathematical model of the combined cycle according to the different characteristics of the components.
00102079 New concept of power generation analysis for chemical gas turbine in thermodynamic process with heat sources or cooling devices Yokogawa, M. FACT iAn1. Sot,. Mrch. &lp.i, IYYX. I. 427~431. A thermodynamic process of power generation was developed for gas turbines many years ago, supported by adiabatic expansion and compression. In recent months. the possible inlet temperature of gas turbines has increased to 1500”. so its blades of high temperature side have to be cooled by some fluid. If we use the actual adiabatic expansion, it is necessary to check the fluid-dynamic friction caused by fluid flow between the blades. In this case, the gas turbine blades have a cooling effect and frictional heat-generating effect. as well. If new concept is introduced, the chemical gas turbine, which creates a reheating effect by heat sources in the expansion process, the outlet temperature of the gas turbine will be increased by this continous reheating effect. Therefore, when the performance of a chemical gas turbine is estimated, these cooling, frictional and reheating effects have to be assessed using theoretical and experimental procedures. The authors here analyse the thermodynamic process with heat sources or cooling devices to illustrate their theoretical approach to estimating these effects. In this study, to analyse each heating or cooling process the definition of the heat exchange route has to be introduced. If this heat-exchange rate is introduced into this analysis of the thermodynamic process, it is possible to differentiate between adiabatic, cooling and heating processes in gas turbines and other machines. New type of lubricant additives for protecting the engines and the environment
00102080
Fodor, J. and Schofield, J. Per. Cot//. 1998. 40. (3). 154-l 5.5. This article presents a new form of lubricating oil additives that consist of a heteropolar organic molecule with dual properties as a hydrogen donor and acceptor. This new type of lubricant additives resulted in the reduction of wear, friction, oil consumption, fuel consumption. harmful emission and restored the cylinder compression. These compounds are 1000/r organic, free from environmental poisoning components as metals, sulfur, phosphorous or halogens.
00/02081 Performance enhancement in coal fired thermal power plant. Part IV: overall system Bhatt, M. S. Int. J. of Oter,q Rcs.. 1999. 23. (14). 1239. 1266. This paper provides an analysis of the overall performance of 22 coal-fired power plants. The net overall efficiency is in the range 19.2%30.69%. The effects of ash in coal, contaminants in feed water. leakage, and incondensables have been quantified. Ways of minimizing secondary oil consumption have been provided. The techniques for performance improvement, low cost as well as capital intensive. have heen described. The role of overhauling the plant and associated opportunities for performance improvement are also discussed. It is concluded that achieving a high annual plant load factor (PLF) will bring about all round improvement in the unit performance. Unless the pressing problems of high ash in coal, inadequate contaminant control and leakage/ingress are solved, mere re-powering by equipment of higher efficiency may not yield the desired results. Design margins of IO-20% are essential for both repowered and new units. In the long term, it is economical to de-commission all units below 210 MW and only three sizes need be retained: 210, 500 and 1000 MW. Automation of the DM water plant provides maximum economic advantage. Considerable opportunity exists for energy conservation through introduction of information technology and variable frequency drives in all units.
00102082 Power generation and aeropropuision gas turbines: from combustion science to combustion technology Correa, S. M. SJ.,~/J. ilr1r.j Comh~,~t.. [Prw.). 1998. 2. 1793-1807. The gas-turbine engine was introduced to society in 1948 and since has become an essential component of our global society. One need only look at the nearest airport to realize its dominance of air transportation. For the power-generation industry It has also hecome a significant element. In the last decade, power-generating combined-cycle power plants have increased in thermal efficiency to about 60%,. while NO, emissions have heen reduced by an order of magnitude, to below 9 ppm (dry, at 15% O?) in some cases. This paper reviews the ongoing transition from science to the needed technologies. For example, new modes of combustion have been introduced in gas turbines. including catalytic combustion, lean premixed combustion. reheat and axially staged combustion, and rich-lean combustion; highefficiency low-emissions performance is being extended to fuels such as coal gas and crude oil that are classed as non-premium; new materials such as superalloys, thermal barrier coatings and ceramics have been incorporated into designs. Future challenges-such as viable propulsion for supersonic transports. power plants fueled by renewable resources and extension of gas turbines to micropower applications-can he met only through further progress in the underlying aerothermal and materials science\.
00102083 Shift reactors and physical absorption for low-CO, emission IGCCs. Chiesa, P. and Consonni, S. J. Eqq Cm 7’1~rhrm~.v F’wI~w. 19Y9. 12I. (2). 295 305. Integrated gasification combined cycle\ (IGCC) exhibit conditions particularly favourable to the sequestration of CO:. This paper focuses on the generation of syngas with a low carbon content. where most of the heating value of the coal fuel is carried by hydrogen. Majority of the CO in the syngas is converted into CO-. by catalytic shift reactors. which is subsequently removed by physical absorption and then compressed to make it suitable for transport and permanent storage. Energy halances, performance and cost of electricity are evaluated for two plants based on a Texaco gasifier and a large. heavy-duty gas turbine giving an overall IGCC power output between 350 and 400 MW. In one plant. the raw \yngas exiting the gasifier is cooled in a high-temperature radiative cooler; in the other the Injection of liquid water is used to quench it. With respect to ‘conventional’ Texaco IGCCs, the reduction of specific CO2 emissions by Oil percent reduces LHV efficiency from five to seven percentage points and increases the cost of electricity of about 40%. These penalties can he reduced by accepting lower reductions of CO2 emissions. The plants analysed here exhibit higher efficiency over the whole range of specific CO: emissions, in comparison to the semi-closed cycle, where CO+ the main component of the gas turbine working fluid.
00102084 Staged catalytic ammonia decomposition in integrated gasification combined cycle systems Feitelberg,A. S. U.S. US 5.912.108 (Cl. 4X-l97R: ClOJI’20), IS
Jun 1900, US Appl. 269,797, 30 Jun 1994. X. Ammonia decomposition can be used to reduce the content of ammonia in fuel gas in an IGCC power generation system. thereby reducing the NO, emissions from the plant. The power generation system includes a gasifier, a gas turbine and at least one catalytic reactor arranged between the gasifier and the gas turbine. The catalytic reactor may be a two-stage or a threestage device. The three-stage reactor includes a first catalyst that promotes water-gas-shift. a second catalyst that promotes carbon monoxide methanation. and a third catalyst, which promotes ammonia decomposition. The two-stage reactor includes a first catalyst. which promotes water-gas-shift and carbon monoxide methanation and a second catalyst. which promotes ammonia decomposition. The plural catalytic stages may be disposed in a single vessel or successively disposed in individual vessel\. and the catalysts may be in a pelletized form or coated on honeycomb structure\. Alternatively, fluidized hed reactors may he used. The reactions are carried out either adiabatically or non-adiabatically. Steam may he generated from heat from the water-gas-shift and carbon monoxide methanation reactions. which can be injected downstream or sent to a steam turbine. Preferably, a second catalytic reactor is provided in parallel with the first reactor so that the two reactors can alternately receive fuel gas from the gasifier.
The effect of using 30% iso-butanol-gasoline blend on hydrocarbon emissions from a spark-ignition engine
00102085
Alasfour, F. N. Encr~l .Sor~r~~~\.1999. 21. (5), 37Y-394. An experimental investigation was carried out into the level of hydrocarbon (HC) emissions, from a spark-ignition engine using a 30”/r iso-hutanolgasoline blend. Studies were conducted on a hydra single-cylinder, sparkignition, fuel-injection engine. HC emissions were measured as a function of fuel/air equivalence ratio, ignition timing and engine speed. The effect of was also varying the cooling water temperature on HC emissions investigated under three fuel/air equivalence ratios (lean, stoichiometrlc. and rich). Results show that retarding ignition timing with respect to maximum break torque (MBT) has a great effect on HC emissions reduction, where for lean mixtures, o = 0.85, retarding ignition timing by six degrees from MBT reduces the exhaust HC emissions by 12%. The level of HC emissions is also reduced by 30 $6 at MBT, as the cooling water temperature increase from 55 to 90”. It has also been notedthat there is a decrease in HC emissions as the speed of the engine decreases.
Fuel and Energy Abstracts
July 2000
231
W/O2077
Gasification power plant
Fukuhara, K. Jpn. Kokai Tokkyo Koho JP I I 116.975 [9Y 1lh.Y7Sj (Cl. ClOK3/00), 27 Apr 1999, Appl. 97/284,X51, 17 Ott 1997. 7. (In Japanese) Gasification power plants that also contain a gas refining apparatus, obtain their gas supply from a gasifier. The gas turbine uses gas from the gas refining apparatus as fuel. A partial combustion device is positioned on the supply path from the gasifier to the gas refining apparatus, or on a parallel bypass path, it is arranged there to lower the oxygen concentration in gas.
00/02078 Mathematical model of coke-carried-heat gasification coal-fired combined cycle Zhao, L. and Xu. X. Gorr,gc.hPri,g&vI,I~/; X&tro. 1999. 20, ( I ). 26.-29. (In Chinese) Coal-fired combined cycles that demonstrate high efficiency and low pollution combustion technology have developed extremely quickly in recent years. In 1992 a novel combined cycle system was put forward by the thermal engineering department of Tsinghua University. The improved system type is now named coke-carried-heat gasification coal-fired combined cycle, in which the gasification chamber was moved from inside the boiler to the outside as a separate gasifier and the coke is used as the gasification heat source. This paper adopted cell model and modular method, in order to develop a mathematical model of the combined cycle according to the different characteristics of the components.
00102079 New concept of power generation analysis for chemical gas turbine in thermodynamic process with heat sources or cooling devices Yokogawa, M. FACT iAn1. Sot,. Mrch. &lp.i, IYYX. I. 427~431. A thermodynamic process of power generation was developed for gas turbines many years ago, supported by adiabatic expansion and compression. In recent months. the possible inlet temperature of gas turbines has increased to 1500”. so its blades of high temperature side have to be cooled by some fluid. If we use the actual adiabatic expansion, it is necessary to check the fluid-dynamic friction caused by fluid flow between the blades. In this case, the gas turbine blades have a cooling effect and frictional heat-generating effect. as well. If new concept is introduced, the chemical gas turbine, which creates a reheating effect by heat sources in the expansion process, the outlet temperature of the gas turbine will be increased by this continous reheating effect. Therefore, when the performance of a chemical gas turbine is estimated, these cooling, frictional and reheating effects have to be assessed using theoretical and experimental procedures. The authors here analyse the thermodynamic process with heat sources or cooling devices to illustrate their theoretical approach to estimating these effects. In this study, to analyse each heating or cooling process the definition of the heat exchange route has to be introduced. If this heat-exchange rate is introduced into this analysis of the thermodynamic process, it is possible to differentiate between adiabatic, cooling and heating processes in gas turbines and other machines. New type of lubricant additives for protecting the engines and the environment
00102080
Fodor, J. and Schofield, J. Per. Cot//. 1998. 40. (3). 154-l 5.5. This article presents a new form of lubricating oil additives that consist of a heteropolar organic molecule with dual properties as a hydrogen donor and acceptor. This new type of lubricant additives resulted in the reduction of wear, friction, oil consumption, fuel consumption. harmful emission and restored the cylinder compression. These compounds are 1000/r organic, free from environmental poisoning components as metals, sulfur, phosphorous or halogens.
00/02081 Performance enhancement in coal fired thermal power plant. Part IV: overall system Bhatt, M. S. Int. J. of Oter,q Rcs.. 1999. 23. (14). 1239. 1266. This paper provides an analysis of the overall performance of 22 coal-fired power plants. The net overall efficiency is in the range 19.2%30.69%. The effects of ash in coal, contaminants in feed water. leakage, and incondensables have been quantified. Ways of minimizing secondary oil consumption have been provided. The techniques for performance improvement, low cost as well as capital intensive. have heen described. The role of overhauling the plant and associated opportunities for performance improvement are also discussed. It is concluded that achieving a high annual plant load factor (PLF) will bring about all round improvement in the unit performance. Unless the pressing problems of high ash in coal, inadequate contaminant control and leakage/ingress are solved, mere re-powering by equipment of higher efficiency may not yield the desired results. Design margins of IO-20% are essential for both repowered and new units. In the long term, it is economical to de-commission all units below 210 MW and only three sizes need be retained: 210, 500 and 1000 MW. Automation of the DM water plant provides maximum economic advantage. Considerable opportunity exists for energy conservation through introduction of information technology and variable frequency drives in all units.
00102082 Power generation and aeropropuision gas turbines: from combustion science to combustion technology Correa, S. M. SJ.,~/J. ilr1r.j Comh~,~t.. [Prw.). 1998. 2. 1793-1807. The gas-turbine engine was introduced to society in 1948 and since has become an essential component of our global society. One need only look at the nearest airport to realize its dominance of air transportation. For the power-generation industry It has also hecome a significant element. In the last decade, power-generating combined-cycle power plants have increased in thermal efficiency to about 60%,. while NO, emissions have heen reduced by an order of magnitude, to below 9 ppm (dry, at 15% O?) in some cases. This paper reviews the ongoing transition from science to the needed technologies. For example, new modes of combustion have been introduced in gas turbines. including catalytic combustion, lean premixed combustion. reheat and axially staged combustion, and rich-lean combustion; highefficiency low-emissions performance is being extended to fuels such as coal gas and crude oil that are classed as non-premium; new materials such as superalloys, thermal barrier coatings and ceramics have been incorporated into designs. Future challenges-such as viable propulsion for supersonic transports. power plants fueled by renewable resources and extension of gas turbines to micropower applications-can he met only through further progress in the underlying aerothermal and materials science\.
00102083 Shift reactors and physical absorption for low-CO, emission IGCCs. Chiesa, P. and Consonni, S. J. Eqq Cm 7’1~rhrm~.v F’wI~w. 19Y9. 12I. (2). 295 305. Integrated gasification combined cycle\ (IGCC) exhibit conditions particularly favourable to the sequestration of CO:. This paper focuses on the generation of syngas with a low carbon content. where most of the heating value of the coal fuel is carried by hydrogen. Majority of the CO in the syngas is converted into CO-. by catalytic shift reactors. which is subsequently removed by physical absorption and then compressed to make it suitable for transport and permanent storage. Energy halances, performance and cost of electricity are evaluated for two plants based on a Texaco gasifier and a large. heavy-duty gas turbine giving an overall IGCC power output between 350 and 400 MW. In one plant. the raw \yngas exiting the gasifier is cooled in a high-temperature radiative cooler; in the other the Injection of liquid water is used to quench it. With respect to ‘conventional’ Texaco IGCCs, the reduction of specific CO2 emissions by Oil percent reduces LHV efficiency from five to seven percentage points and increases the cost of electricity of about 40%. These penalties can he reduced by accepting lower reductions of CO2 emissions. The plants analysed here exhibit higher efficiency over the whole range of specific CO: emissions, in comparison to the semi-closed cycle, where CO+ the main component of the gas turbine working fluid.
00102084 Staged catalytic ammonia decomposition in integrated gasification combined cycle systems Feitelberg,A. S. U.S. US 5.912.108 (Cl. 4X-l97R: ClOJI’20), IS
Jun 1900, US Appl. 269,797, 30 Jun 1994. X. Ammonia decomposition can be used to reduce the content of ammonia in fuel gas in an IGCC power generation system. thereby reducing the NO, emissions from the plant. The power generation system includes a gasifier, a gas turbine and at least one catalytic reactor arranged between the gasifier and the gas turbine. The catalytic reactor may be a two-stage or a threestage device. The three-stage reactor includes a first catalyst that promotes water-gas-shift. a second catalyst that promotes carbon monoxide methanation. and a third catalyst, which promotes ammonia decomposition. The two-stage reactor includes a first catalyst. which promotes water-gas-shift and carbon monoxide methanation and a second catalyst. which promotes ammonia decomposition. The plural catalytic stages may be disposed in a single vessel or successively disposed in individual vessel\. and the catalysts may be in a pelletized form or coated on honeycomb structure\. Alternatively, fluidized hed reactors may he used. The reactions are carried out either adiabatically or non-adiabatically. Steam may he generated from heat from the water-gas-shift and carbon monoxide methanation reactions. which can be injected downstream or sent to a steam turbine. Preferably, a second catalytic reactor is provided in parallel with the first reactor so that the two reactors can alternately receive fuel gas from the gasifier.
The effect of using 30% iso-butanol-gasoline blend on hydrocarbon emissions from a spark-ignition engine
00102085
Alasfour, F. N. Encr~l .Sor~r~~~\.1999. 21. (5), 37Y-394. An experimental investigation was carried out into the level of hydrocarbon (HC) emissions, from a spark-ignition engine using a 30”/r iso-hutanolgasoline blend. Studies were conducted on a hydra single-cylinder, sparkignition, fuel-injection engine. HC emissions were measured as a function of fuel/air equivalence ratio, ignition timing and engine speed. The effect of was also varying the cooling water temperature on HC emissions investigated under three fuel/air equivalence ratios (lean, stoichiometrlc. and rich). Results show that retarding ignition timing with respect to maximum break torque (MBT) has a great effect on HC emissions reduction, where for lean mixtures, o = 0.85, retarding ignition timing by six degrees from MBT reduces the exhaust HC emissions by 12%. The level of HC emissions is also reduced by 30 $6 at MBT, as the cooling water temperature increase from 55 to 90”. It has also been notedthat there is a decrease in HC emissions as the speed of the engine decreases.
Fuel and Energy Abstracts
July 2000
231