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Combustion-gasification furnace for low-rank fuels
09 Combustion (burners, combustion systems) 00100457 Combustion system with conversion of hydrocarbon fuels and removal of carbon dioxide Nakagawa, K. and Ohashi, T. Jpn. Kokai Tokkyo Koho JP 11 263,988 [99 263,988] (Cl. ClOK1/12), 28 Sep 1999, Appi. 1998/66,659, 17 Mar 1998. 6. (In Japanese) The combustion system under discussion, includes a means for converting hydrocarbon fuels, such as petroleum and coal into a gas, which contains CO, Hz; and COz. The system also has a means for desuifurizing the gas, a means for CO conversion (by steam reforming) to form hydrogen and carbon dioxide, a process for separating CO1 from the gas using lithium zirconate without cooling, plus a procedure for combusting the hydrogen-rich gas that is produced.
2;0458
Combustion-gasification furnace for low-rank
Makino, K. and Yoshikawa, K. Jpn. Kokai Tokkyo Koho JP 11 209,764 [99 209,764] (Cl. ClOJ3/46), 3 Aug 1999, Appi. 1998/10,905, 23 Jan 1998. 5. (In Japanese) A furnace for the combustion-gasification of low-rank ceais (e.g. coal ash or carbon containing ash), consists of a reactor for combustiongasification of fuels and a separation chamber for gravity separation of reaction gas and fused ash connected at the lower part of the reactor. The reactor consists of a combustor at the top of the reactor for oxidation of the fuel with the oxidizing agent, a gas reaction space under the combustor and a ceramic packed layer in the lower part of the gas reaction space. It is the ceramic packed layer where the fused ash is deposited and drops of slag, fly ash and unburnt carbon are collected from the fused ash, when the reaction gas contacts it.
The ratio between the critical heat fluxes in kerosene boiling on fresh surfaces that have been in operation are not affected by underheating and pressure. This work is significant for the cooling of jet engines with boiling kerosene (fuel). 00100482 Equilibrium and kinetic modeling of the pyrolysis and oxidation of hydrocarbons at high pressures Dvornikov, N. A. Fiz. Goreniya Vzryva, 1999, 35, (3), 20-28. (In Russian) Numerical modeiiing of the pyrolysis and incomplete oxidation of hydrocarbons in the presence of water at high pressures was performed. The calculated results indicate that gas nonideaiity can have significant effects on composition and temperature of the reaction products. Although the calculated values obtained for equilibrium and global kinetics mutually agreed better, the detailed kinetic model and the experimental data correspond better.
Experimental study and theoretical analysis of fixed-bed biomass pyrolysis 00/00453
Chen, G. er al. Taiyangneng Xuebao, 1999, 20, (2), 122-129. (In Chinese) The effect of pyrolysis temperature on the fiied bed pyrolytic characteristics of rice husk, rice straw and sawdust was studied in detail and an analysis of the pyrolytic products was performed. Gas yield is 0.25-0.45 Nm3/kg biomass, depending on temperature of pyrolysis and the type of biomass. The caiorific value of the gas is 12000-15 000 kJ/Nm3,, which is suitable for household uses. After modification, it is posslbie to use tar as a fuel oil.
Flash pyrolysis of oil shales in a fiuidized bed
00100459 Comparison of products from the pyrolysis and catalytic pyrolysis of rice husks
00100484
Williams, P. T. and Nugranad, N. Energy, 2000, 25, (6), 493-513. Rice husks were pyroiysed in a fluidized bed reactor at 400, 450, 500, 550 and 600°C. The rice husks were then pyroiysed at 550°C with zeoiite ZSMJ catalyst upgrading of the pyrolysis vapours at catalyst temperatures of 400, 450, 500, 550, and 600°C. The pyrolysis oils were collected in a series of condensers and cold traps and anaiysed to determine their yield and composition in relation to process conditions. The gases were anaiysed off-line by packed column gas chromatography. The pyrolysis oils before catalysis were homogeneous, of low viscosity and highly oxygenated. Poiycyciic aromatic hydrocarbons (PAH) were present in the oils at low concentration and increased in concentration with increasing temperature of pyrolysis. Oxygenated compounds in the oils consisted mainly of phenols, cresois, benzenediois and guaiacoi and their aikyiated derivatives. In the presence of the catalyst the yield of oil was markedly reduced, although the oxygen content of the oil was reduced with the formation of coke on the catalyst. The influence of the catalyst was to convert the oxygen in the pyrolysis oil to largely Hz0 at the lower catalyst temperatures and to largely CO and CO2 at the higher catalyst temperatures. The molecular weight distribution of the oils was decreased after catalysis and further decreased with increasing temperature of catalysis. The cataiysed oils were markedly increased in single ring and PAH compared to uncataiysed biomass pyrolysis oils. The concentration of aromatic and poiycyciic aromatic species increased with increasing catalyst temperature.
Khraisha, Y. H. Energy Comers. Manage., 2000, 41, (15), 1729-1739. The pyrolysis behaviour of EL-Lajjun and Suitani oil shales was investigated under rapid heating conditions using a bench scale fluidized bed reactor. Shale particles were fed continuously (7 g h-‘) in a bed of sand fluidized by Nz gas. Experiments were conducted over a range of temperatures, 400-5Oo”C, and with three particle size fractions, 250-355, 355-500 and 500-710 pm. Increasing the pyrolysis temperature resulted in increasing the oil yields, but at temperatures over 475”C, the increase became small. Over the tested range, particle size showed little effect on oil yields. A simple first order devoiatiiization model adequately describes the pyrolysis process. The rate constants and activation energies for the two oil shales were deduced.
Effect of duration of surface o eration on the critical heat flux In surface boiling of un$ erheated kerosine
00100481
48
S. G. Izv. Vyssh. Uchebn. (In Russian)
1998, 5, 80-85.
Fuel and Energy Abstracts
Zaved.
Energ.
Jahuaty 2001
Ob’edin.
Gadgii, K. Indian J. Environ. Pro!., 1999, 19, (5), 360-362. A number of furnaces, in particular small-scale ones are highly polluting. The glass, ceramic and pottery industries have examples of such furnaces. Low grade coal and other carbonaceous materials could be gasified to produce gas at high temperatures, which could be burnt in a pollution-free manner in these furnaces. It is essential for this purpose that developments to both the burner and the gasifier are carried out. Some of this developmental work is presented in this paper.
Influence on the combustion stability of a high energy propellent by impacted damage state
Cagiar, A. and Demirbas, A. Energy Convers. Manage., 2000, 41, (15), 1749-1756. The most attractive product from pyrolysis of biomass is the liquid phase. The nature of conversion of cotton cocoon shell by pyrolysis to liquid products has been studied in the presence of alkali additives. The final temperature limits of the pyrolysis processes were 620-820 K. The yield of conversion with Na2C03 additive (20% by weight) to liquid and gaseous products increased from 63.8% to 73.0%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 48.8% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 32.2%. The yield of conversion with KzCOj additive (20% by weight) to liquid and gaseous products increased from 65.5% to 73.7%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 53.5% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 30.2%. The yield of liquid increased only 3.1% in the presence of NazCOs (20% of the sample) at 620 K. Indeed, the highest yield of liquid was 7.5% in the presence of K&O3 (20% of the sample) at a final pyrolysis temperature of 620 K.
Obukhov,
Gasification for clean combustion in highly polluting furnaces OOlOO485
00/00488
Conversion of cotton cocoon shell to liquid products by pyrolysis
00100480
Energ.,
reactor
SNG.
Zhang, T. et al. Lfoazha Yu Chongji, 1999, 19, (3), 210-215. (In Chinese) Low-speed impact tests for inducing damage were conducted on NEPE (nitrate ester plasticized poiyether) by using the large-scale drop weight apparatus. It was shown that the matrix materials were destroyed and the particle-filled materials were unchanged when they were anaiysed using scanning electron microscopy. The closed-bomb tests had shown that the apparent burn rates of the impact-damaged NEPE propellants varied considerably. 00/00457 Laminar flamelet expressions for pressure fluctuation terms in second moment models of premixed turbulent combustion F;5rino, P. and Bray, K. N. C. Combusrion and Flame, 2000, 121, (4), New reacting flow models are proposed and tested for all pressure fluctuation co-variances that are known to play a crucial role in the second moment closure of the averaged equations of turbulent flows. The models, which are applicable to the thin iaminar flameiet regime of premixed turbulent combustion, are based on a partitioning of each wvariance into contributions from reactants, products and thin fiameiets. Intermittency between the conditional mean pressure gradients in reactants and products is found to play an important role in the resulting expressions. The proposed models are extensively tested using two-dimensional direct numerical simulation (DNS) of premixed combustion in decaying turbulence. The compressible flow code includes effects of finite heat release controlled by an assumed
2;0458
Combustion-gasification furnace for low-rank
Makino, K. and Yoshikawa, K. Jpn. Kokai Tokkyo Koho JP 11 209,764 [99 209,764] (Cl. ClOJ3/46), 3 Aug 1999, Appi. 1998/10,905, 23 Jan 1998. 5. (In Japanese) A furnace for the combustion-gasification of low-rank ceais (e.g. coal ash or carbon containing ash), consists of a reactor for combustiongasification of fuels and a separation chamber for gravity separation of reaction gas and fused ash connected at the lower part of the reactor. The reactor consists of a combustor at the top of the reactor for oxidation of the fuel with the oxidizing agent, a gas reaction space under the combustor and a ceramic packed layer in the lower part of the gas reaction space. It is the ceramic packed layer where the fused ash is deposited and drops of slag, fly ash and unburnt carbon are collected from the fused ash, when the reaction gas contacts it.
The ratio between the critical heat fluxes in kerosene boiling on fresh surfaces that have been in operation are not affected by underheating and pressure. This work is significant for the cooling of jet engines with boiling kerosene (fuel). 00100482 Equilibrium and kinetic modeling of the pyrolysis and oxidation of hydrocarbons at high pressures Dvornikov, N. A. Fiz. Goreniya Vzryva, 1999, 35, (3), 20-28. (In Russian) Numerical modeiiing of the pyrolysis and incomplete oxidation of hydrocarbons in the presence of water at high pressures was performed. The calculated results indicate that gas nonideaiity can have significant effects on composition and temperature of the reaction products. Although the calculated values obtained for equilibrium and global kinetics mutually agreed better, the detailed kinetic model and the experimental data correspond better.
Experimental study and theoretical analysis of fixed-bed biomass pyrolysis 00/00453
Chen, G. er al. Taiyangneng Xuebao, 1999, 20, (2), 122-129. (In Chinese) The effect of pyrolysis temperature on the fiied bed pyrolytic characteristics of rice husk, rice straw and sawdust was studied in detail and an analysis of the pyrolytic products was performed. Gas yield is 0.25-0.45 Nm3/kg biomass, depending on temperature of pyrolysis and the type of biomass. The caiorific value of the gas is 12000-15 000 kJ/Nm3,, which is suitable for household uses. After modification, it is posslbie to use tar as a fuel oil.
Flash pyrolysis of oil shales in a fiuidized bed
00100459 Comparison of products from the pyrolysis and catalytic pyrolysis of rice husks
00100484
Williams, P. T. and Nugranad, N. Energy, 2000, 25, (6), 493-513. Rice husks were pyroiysed in a fluidized bed reactor at 400, 450, 500, 550 and 600°C. The rice husks were then pyroiysed at 550°C with zeoiite ZSMJ catalyst upgrading of the pyrolysis vapours at catalyst temperatures of 400, 450, 500, 550, and 600°C. The pyrolysis oils were collected in a series of condensers and cold traps and anaiysed to determine their yield and composition in relation to process conditions. The gases were anaiysed off-line by packed column gas chromatography. The pyrolysis oils before catalysis were homogeneous, of low viscosity and highly oxygenated. Poiycyciic aromatic hydrocarbons (PAH) were present in the oils at low concentration and increased in concentration with increasing temperature of pyrolysis. Oxygenated compounds in the oils consisted mainly of phenols, cresois, benzenediois and guaiacoi and their aikyiated derivatives. In the presence of the catalyst the yield of oil was markedly reduced, although the oxygen content of the oil was reduced with the formation of coke on the catalyst. The influence of the catalyst was to convert the oxygen in the pyrolysis oil to largely Hz0 at the lower catalyst temperatures and to largely CO and CO2 at the higher catalyst temperatures. The molecular weight distribution of the oils was decreased after catalysis and further decreased with increasing temperature of catalysis. The cataiysed oils were markedly increased in single ring and PAH compared to uncataiysed biomass pyrolysis oils. The concentration of aromatic and poiycyciic aromatic species increased with increasing catalyst temperature.
Khraisha, Y. H. Energy Comers. Manage., 2000, 41, (15), 1729-1739. The pyrolysis behaviour of EL-Lajjun and Suitani oil shales was investigated under rapid heating conditions using a bench scale fluidized bed reactor. Shale particles were fed continuously (7 g h-‘) in a bed of sand fluidized by Nz gas. Experiments were conducted over a range of temperatures, 400-5Oo”C, and with three particle size fractions, 250-355, 355-500 and 500-710 pm. Increasing the pyrolysis temperature resulted in increasing the oil yields, but at temperatures over 475”C, the increase became small. Over the tested range, particle size showed little effect on oil yields. A simple first order devoiatiiization model adequately describes the pyrolysis process. The rate constants and activation energies for the two oil shales were deduced.
Effect of duration of surface o eration on the critical heat flux In surface boiling of un$ erheated kerosine
00100481
48
S. G. Izv. Vyssh. Uchebn. (In Russian)
1998, 5, 80-85.
Fuel and Energy Abstracts
Zaved.
Energ.
Jahuaty 2001
Ob’edin.
Gadgii, K. Indian J. Environ. Pro!., 1999, 19, (5), 360-362. A number of furnaces, in particular small-scale ones are highly polluting. The glass, ceramic and pottery industries have examples of such furnaces. Low grade coal and other carbonaceous materials could be gasified to produce gas at high temperatures, which could be burnt in a pollution-free manner in these furnaces. It is essential for this purpose that developments to both the burner and the gasifier are carried out. Some of this developmental work is presented in this paper.
Influence on the combustion stability of a high energy propellent by impacted damage state
Cagiar, A. and Demirbas, A. Energy Convers. Manage., 2000, 41, (15), 1749-1756. The most attractive product from pyrolysis of biomass is the liquid phase. The nature of conversion of cotton cocoon shell by pyrolysis to liquid products has been studied in the presence of alkali additives. The final temperature limits of the pyrolysis processes were 620-820 K. The yield of conversion with Na2C03 additive (20% by weight) to liquid and gaseous products increased from 63.8% to 73.0%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 48.8% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 32.2%. The yield of conversion with KzCOj additive (20% by weight) to liquid and gaseous products increased from 65.5% to 73.7%, while the final pyrolysis temperature was increased from 620 to 820 K. While the liquid yield was 53.5% at a pyrolysis temperature of 620 K, at the final pyrolysis temperature of 820 K, the oil yield decreased to 30.2%. The yield of liquid increased only 3.1% in the presence of NazCOs (20% of the sample) at 620 K. Indeed, the highest yield of liquid was 7.5% in the presence of K&O3 (20% of the sample) at a final pyrolysis temperature of 620 K.
Obukhov,
Gasification for clean combustion in highly polluting furnaces OOlOO485
00/00488
Conversion of cotton cocoon shell to liquid products by pyrolysis
00100480
Energ.,
reactor
SNG.
Zhang, T. et al. Lfoazha Yu Chongji, 1999, 19, (3), 210-215. (In Chinese) Low-speed impact tests for inducing damage were conducted on NEPE (nitrate ester plasticized poiyether) by using the large-scale drop weight apparatus. It was shown that the matrix materials were destroyed and the particle-filled materials were unchanged when they were anaiysed using scanning electron microscopy. The closed-bomb tests had shown that the apparent burn rates of the impact-damaged NEPE propellants varied considerably. 00/00457 Laminar flamelet expressions for pressure fluctuation terms in second moment models of premixed turbulent combustion F;5rino, P. and Bray, K. N. C. Combusrion and Flame, 2000, 121, (4), New reacting flow models are proposed and tested for all pressure fluctuation co-variances that are known to play a crucial role in the second moment closure of the averaged equations of turbulent flows. The models, which are applicable to the thin iaminar flameiet regime of premixed turbulent combustion, are based on a partitioning of each wvariance into contributions from reactants, products and thin fiameiets. Intermittency between the conditional mean pressure gradients in reactants and products is found to play an important role in the resulting expressions. The proposed models are extensively tested using two-dimensional direct numerical simulation (DNS) of premixed combustion in decaying turbulence. The compressible flow code includes effects of finite heat release controlled by an assumed