- Email: [email protected]
04011 Combustion of fuel blends
09 NO, reduction, but less effective for NzO reduction; the optimum value of the ratio of primary/ total air was -0.8 for minimizing NO, emissions. Limestone injection at calcium-sulfur molar ratios >2:1 made it possible to remove >90% of SOz formed, although two-stage combustion and decreased concentration of in-bed oxygen brought about a decrease in SOz removal efficiency. Consequently, using a two-stage combustion scheme, lignite can be burned at fairly low levels of NO,, NzO, and SOz emissions when limestone is added into fluidized-bed combustor.
Combustion characteristics and growth of carbon deposited on a coke-oven wall
Combustion
(burners, combustion
systems)
The combustion of alternative solid fuels in rotary cement kilns, and their handling
98/04009
Paulin, F. ZKG Int., 1998, 51, (l), 30-32, 34-36, 38. (In English/German) According to their physical properties, the fuels are classified into four groups. Economic, technical and legal aspects of utilizing alternative, solid fuels are discussed and flow sheets are given to illustrate their handling. In addition, the introduction of a software program for the early detection of problems during processing which may arise from the application of the title fuels is included.
96lo4004
Kim, K.-H. and Lee, Y.-K. Hwnhak Konghak, 1997, 35, (6), 863-869. (In Korean) This study attempts to understand the growth of carbon and combustion characteristics and estimate the quantity of carbon deposited on the coke oven ,wall. The growth mechanism of deposited carbon sampled in the different positions of coking chamber was examined. A nuclei test product was produced from the condensation of pulverized coal and tar vapour and then it was grown by pyrolysis, resulting in carbon formation. A small carbonization oven was used to predict the deposition rate of carbon. It was assumed that the carbon deposition in coke oven wall carbonizing about 33 tons coal was 4.56 kg and the capacity of fan supplying air for combustion was over 70 Nm”/min.
Combustion characteristics of intensively cleaned 96lO4665 coal fractions. Effect of mineral matter Rubiera, F. er al. DGMK Tugungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 1003-1006. The influence of intensive coal cleaning on the combustion behaviour of different density-separated coal fractions is investigated. Density separation obtained samples with ash contents varying from 39% for the raw coal to 2% for the cleanest fraction. Temperature-programmed combustion and isothermal gasification in air were used to measure the reactivities of the parent coal and the cleaned fractions. With the increasing ash content of the samples, the coal and char reactivities increased. Thermal analysis-mass spectrometry of the low-temperature ashes was also carried out in order to study the reactions of coal minerals under combustion conditions.
Combustion method and apparatus for waxy fuels 96lO4006 from recycling of plastic wastes Kamegawa, M. Jpn. Kokai Tokkyo Koho JP 09 53,817 [97 53,817] (Cl. F23G7/12), 25 Feb 1997, Appl. 951230,692, 17 Aug 1995, 6 pp. (In Japanese) Fuels are charged into molten tanks and heated without oxygen under reduced pressure, melted and boiled to produce combustible gases. The gases are then mixed with air and combusted. Polypropylene or polyethylene wastes were recycled and thermally decomposed to form waxy fuels, which were combusted as above.
Combustion of a coal-oil mixture drop in a microgravity environment
96lQ4007
Tanishige, R. et al. Proc. ASME-JSME Therm. Eng. Jt. Conf., 4th, 1995, 4, 519-526. Edited by Fletcher, L. S. and Aihara, T., American Society of Mechanical Engineers, New York. Under normal and micro gravity conditions, the ignition and combustion characteristics of a coal-oil mixture drop were measured to get a fundamental understanding on the combustion process of coal slurry sprays. The experiments were conducted in a drop tower, which has a fall of 710 m and a duration of 10 s of the microgravity condition. Taiheiyo Coal and n-Dodecane were used for the coal-oil mixture with a 50% mixing ratio. The Taiheiyo Coal had a fixed coal mass percentage of 43.03 %, a volatility mass percentage of 40.97 % and an ash mass percentage of 16.00 %. The mass percentage of the Taiheiyo Coal with a diameter smaller than 75 mm was 85.74 %. The COM drop suspended on the tip of a silica-glass thread was carried into a heated electric furnace with a signal at the fall. By means of a 35 mm motor driven still camera and an 8 mm video camera, the ignition and combustion processes of the COM drop were recorded with changes in the ambient temperature. When the experimental results under the microgravity condition and under the normal gravity condition were compared, the differences in the combustion characteristics between the two were clarified. 90lO4006
conditions
Combustion of a single wood log under furnace
Bryden, K. M. and Ragland, K. W. Dev. Thermochem. Biomass Convers., 1997, 2, 1331-1345. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK. Results from combustion experiments investigating large particles (> 10 cm) of thermally thick woody biomass under conditions representative of packed bed combustion. The combustion rate of thermally thick yellow poplar and paper birch tree segments in a typical combustion environment was measured in a special test furnace using load cells to measure mass vs time. Both green and dry woods were tested. A simple relationship for the build-up of the char layer within the range of conditions studied was developed. A numerical model to determine the combustion rate of single logs within the kiln, for the range of experimental values was developed using global reaction rates for combustion and gasification. For nearly all of the 72 data points, agreement between the numerical model and the experimental values is within 30%.
96/04010 fuel gas
Combustion of biomass-derived low calorific value
Hoppesteyn, P. D. J. et al. Combust. Emiss. Control III, 1997, 293-303. Edited by Adams, M., Institute of Energy, London, UK. Partly funded by the EU as a part of their JOULE programme, experimental and theoretical research will be done on the pressurized combustion of biomass-derived low calorific value (LCV) fuel gas as part of a multinational project. European Gas Turbines Ltd. will design, manufacture and supply a pressurized, high temperature combustor for the biomass-derived fuel gas matched to the Delft gasifier. This gasifier has a maximum thermal capacity of 1.5 MW and will operate at pressures up to 10 bar and temperatures of 850°C. The combustor will be installed in the Delft test rig and experiments will be carried out to gather experimental data on the steady state and dynamic behaviour of the combustor. The experimental results will be compared with simulation results obtained from mathematical models describing the steady state and dynamic behaviour of the combustor and used to refine and validate these models. A detailed description will be given of the objectives of the project, the test rig to be used and the time schedule of the project. Furthermore, preliminary experimental results of the combustion of biomass-derived LCV fuel gas in an atmospheric cyclone combustor will be described. 98104011 Combustion of fuel blends Asfar, K. R. and Hamed, H. Energy Convers. Mgmt, 1998, 39, (lo), 10811093. The authors present an experimental investigation of the combustion of various kerosene-diesel and alcohol-diesel fuel blends. In order to study the effect of fuel blends on the combustion process and pollutants in the exhaust gases, tests are conducted in a continuous flow combustor. Exhaust analyses of CO, COz, 02, NO,, HC and soot mass concentration are presented. For the ethanol alcohol-diesel blends, a stabilizer (isobutanol) is added to the mixture to improve and maintain miscibility.
Combustion of old wood in a former refuse burning plant: experiences and consequences
9al04012
Swerev, M. et al. VDI-Ber., 1997, 1313, 615-620. (In German) The paper investigates a closed refuse incinerator plant to determine whether it could feasibly be equipped for use as a biomass burning power plant. A mixture of pre-sorted old wood and forest and sawmill residual wood was proposed as fuel. Based on the results of the research project, the necessary reconstruction was designed, and the modified equipment was due to begin operation in the winter of 1997.
Combustion optimization using an expert system and neural networks
9aiB4013
Levy, E. er al. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996) 411-419. Software has been jointly developed Lehigh University’s Energy Research Center and the Potomac Elec. Power Company for use by plant personnel in tuning a pulverized coal-fired boiler to achieve optimized combustion. Based on the interactions of an expert system, neural networks and a mathematical optimization algorithm, the software uses the expert system to safely guide the plant engineer through a series of parametric boiler tests and gather a database for boiler operation characterization. The neural network portion develops non-linear mapping functions between the outputs of NO,, heat rate, LOI, opacity and the controllable boiler input parameters. These mapping functions are then analysed by the mathematical optimization algorithm and the optimal boiler operating conditions are identified. The application of the software to corner-fired boilers with either conventional or low-NO, burners and overfire air is described.
On the combustion/emissions and pulverized coal
96104014
of tire-derived fuel
Atal, A. and Levendis, Y. A. Chem. Phys. Processes Combusr., 1997, 407410. High-volatile bituminous coal and pulverized waste tyres were combusted to investigate their flame characteristics and temperatures for combustion behaviour and the emissions. An electrically heated drop-tube furnace, operating at 1200°C and gas residence time 0.75 s and from fuel-lean to fuel-rich conditions, was used.
96lo4015 Concepts for lowest NO, release in pulverized coal combustion
Greul, U. et al. Chemical-Ing.-Tech., 1998, 70, (l/2), 165-170 (In German) In pulverized coal combustion, the effects of technological measures on the release of NO, were studied on an experimental entrained flow reactor, employing hard coal and predried brown coal. The influence of temperature, air ratio, air staging, fuel staging, NH3 addition and retention time in
Fuel and Energy Abstracts
September 1996 375
Combustion characteristics and growth of carbon deposited on a coke-oven wall
Combustion
(burners, combustion
systems)
The combustion of alternative solid fuels in rotary cement kilns, and their handling
98/04009
Paulin, F. ZKG Int., 1998, 51, (l), 30-32, 34-36, 38. (In English/German) According to their physical properties, the fuels are classified into four groups. Economic, technical and legal aspects of utilizing alternative, solid fuels are discussed and flow sheets are given to illustrate their handling. In addition, the introduction of a software program for the early detection of problems during processing which may arise from the application of the title fuels is included.
96lo4004
Kim, K.-H. and Lee, Y.-K. Hwnhak Konghak, 1997, 35, (6), 863-869. (In Korean) This study attempts to understand the growth of carbon and combustion characteristics and estimate the quantity of carbon deposited on the coke oven ,wall. The growth mechanism of deposited carbon sampled in the different positions of coking chamber was examined. A nuclei test product was produced from the condensation of pulverized coal and tar vapour and then it was grown by pyrolysis, resulting in carbon formation. A small carbonization oven was used to predict the deposition rate of carbon. It was assumed that the carbon deposition in coke oven wall carbonizing about 33 tons coal was 4.56 kg and the capacity of fan supplying air for combustion was over 70 Nm”/min.
Combustion characteristics of intensively cleaned 96lO4665 coal fractions. Effect of mineral matter Rubiera, F. er al. DGMK Tugungsber., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 1003-1006. The influence of intensive coal cleaning on the combustion behaviour of different density-separated coal fractions is investigated. Density separation obtained samples with ash contents varying from 39% for the raw coal to 2% for the cleanest fraction. Temperature-programmed combustion and isothermal gasification in air were used to measure the reactivities of the parent coal and the cleaned fractions. With the increasing ash content of the samples, the coal and char reactivities increased. Thermal analysis-mass spectrometry of the low-temperature ashes was also carried out in order to study the reactions of coal minerals under combustion conditions.
Combustion method and apparatus for waxy fuels 96lO4006 from recycling of plastic wastes Kamegawa, M. Jpn. Kokai Tokkyo Koho JP 09 53,817 [97 53,817] (Cl. F23G7/12), 25 Feb 1997, Appl. 951230,692, 17 Aug 1995, 6 pp. (In Japanese) Fuels are charged into molten tanks and heated without oxygen under reduced pressure, melted and boiled to produce combustible gases. The gases are then mixed with air and combusted. Polypropylene or polyethylene wastes were recycled and thermally decomposed to form waxy fuels, which were combusted as above.
Combustion of a coal-oil mixture drop in a microgravity environment
96lQ4007
Tanishige, R. et al. Proc. ASME-JSME Therm. Eng. Jt. Conf., 4th, 1995, 4, 519-526. Edited by Fletcher, L. S. and Aihara, T., American Society of Mechanical Engineers, New York. Under normal and micro gravity conditions, the ignition and combustion characteristics of a coal-oil mixture drop were measured to get a fundamental understanding on the combustion process of coal slurry sprays. The experiments were conducted in a drop tower, which has a fall of 710 m and a duration of 10 s of the microgravity condition. Taiheiyo Coal and n-Dodecane were used for the coal-oil mixture with a 50% mixing ratio. The Taiheiyo Coal had a fixed coal mass percentage of 43.03 %, a volatility mass percentage of 40.97 % and an ash mass percentage of 16.00 %. The mass percentage of the Taiheiyo Coal with a diameter smaller than 75 mm was 85.74 %. The COM drop suspended on the tip of a silica-glass thread was carried into a heated electric furnace with a signal at the fall. By means of a 35 mm motor driven still camera and an 8 mm video camera, the ignition and combustion processes of the COM drop were recorded with changes in the ambient temperature. When the experimental results under the microgravity condition and under the normal gravity condition were compared, the differences in the combustion characteristics between the two were clarified. 90lO4006
conditions
Combustion of a single wood log under furnace
Bryden, K. M. and Ragland, K. W. Dev. Thermochem. Biomass Convers., 1997, 2, 1331-1345. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK. Results from combustion experiments investigating large particles (> 10 cm) of thermally thick woody biomass under conditions representative of packed bed combustion. The combustion rate of thermally thick yellow poplar and paper birch tree segments in a typical combustion environment was measured in a special test furnace using load cells to measure mass vs time. Both green and dry woods were tested. A simple relationship for the build-up of the char layer within the range of conditions studied was developed. A numerical model to determine the combustion rate of single logs within the kiln, for the range of experimental values was developed using global reaction rates for combustion and gasification. For nearly all of the 72 data points, agreement between the numerical model and the experimental values is within 30%.
96/04010 fuel gas
Combustion of biomass-derived low calorific value
Hoppesteyn, P. D. J. et al. Combust. Emiss. Control III, 1997, 293-303. Edited by Adams, M., Institute of Energy, London, UK. Partly funded by the EU as a part of their JOULE programme, experimental and theoretical research will be done on the pressurized combustion of biomass-derived low calorific value (LCV) fuel gas as part of a multinational project. European Gas Turbines Ltd. will design, manufacture and supply a pressurized, high temperature combustor for the biomass-derived fuel gas matched to the Delft gasifier. This gasifier has a maximum thermal capacity of 1.5 MW and will operate at pressures up to 10 bar and temperatures of 850°C. The combustor will be installed in the Delft test rig and experiments will be carried out to gather experimental data on the steady state and dynamic behaviour of the combustor. The experimental results will be compared with simulation results obtained from mathematical models describing the steady state and dynamic behaviour of the combustor and used to refine and validate these models. A detailed description will be given of the objectives of the project, the test rig to be used and the time schedule of the project. Furthermore, preliminary experimental results of the combustion of biomass-derived LCV fuel gas in an atmospheric cyclone combustor will be described. 98104011 Combustion of fuel blends Asfar, K. R. and Hamed, H. Energy Convers. Mgmt, 1998, 39, (lo), 10811093. The authors present an experimental investigation of the combustion of various kerosene-diesel and alcohol-diesel fuel blends. In order to study the effect of fuel blends on the combustion process and pollutants in the exhaust gases, tests are conducted in a continuous flow combustor. Exhaust analyses of CO, COz, 02, NO,, HC and soot mass concentration are presented. For the ethanol alcohol-diesel blends, a stabilizer (isobutanol) is added to the mixture to improve and maintain miscibility.
Combustion of old wood in a former refuse burning plant: experiences and consequences
9al04012
Swerev, M. et al. VDI-Ber., 1997, 1313, 615-620. (In German) The paper investigates a closed refuse incinerator plant to determine whether it could feasibly be equipped for use as a biomass burning power plant. A mixture of pre-sorted old wood and forest and sawmill residual wood was proposed as fuel. Based on the results of the research project, the necessary reconstruction was designed, and the modified equipment was due to begin operation in the winter of 1997.
Combustion optimization using an expert system and neural networks
9aiB4013
Levy, E. er al. FACT, 1996, 21, (Proceedings of the International Joint Power Generation Conference, Volume 1: Environmental Control/Fuels and Combustion Technologies, 1996) 411-419. Software has been jointly developed Lehigh University’s Energy Research Center and the Potomac Elec. Power Company for use by plant personnel in tuning a pulverized coal-fired boiler to achieve optimized combustion. Based on the interactions of an expert system, neural networks and a mathematical optimization algorithm, the software uses the expert system to safely guide the plant engineer through a series of parametric boiler tests and gather a database for boiler operation characterization. The neural network portion develops non-linear mapping functions between the outputs of NO,, heat rate, LOI, opacity and the controllable boiler input parameters. These mapping functions are then analysed by the mathematical optimization algorithm and the optimal boiler operating conditions are identified. The application of the software to corner-fired boilers with either conventional or low-NO, burners and overfire air is described.
On the combustion/emissions and pulverized coal
96104014
of tire-derived fuel
Atal, A. and Levendis, Y. A. Chem. Phys. Processes Combusr., 1997, 407410. High-volatile bituminous coal and pulverized waste tyres were combusted to investigate their flame characteristics and temperatures for combustion behaviour and the emissions. An electrically heated drop-tube furnace, operating at 1200°C and gas residence time 0.75 s and from fuel-lean to fuel-rich conditions, was used.
96lo4015 Concepts for lowest NO, release in pulverized coal combustion
Greul, U. et al. Chemical-Ing.-Tech., 1998, 70, (l/2), 165-170 (In German) In pulverized coal combustion, the effects of technological measures on the release of NO, were studied on an experimental entrained flow reactor, employing hard coal and predried brown coal. The influence of temperature, air ratio, air staging, fuel staging, NH3 addition and retention time in
Fuel and Energy Abstracts
September 1996 375