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03232 Product distribution from Yallourn coal by methane microwave plasma conversion
03 Gaseous fuels (derived gaseous fuels)
of possible applicattons for the gasifier are mentioned including as an example a simple and compact system for the co-firing of biomass and waste in power plants. Mathematical modeling of air bubbling processes 00103225 during coal gasification in a slag melt Shaforost, D. A. and Madoyan, A. A. Tcplornergerika (MoscowJ. 1999, 4, 66-69. (In Russian) This paper presents a model of the air bubbling process that occurs during the gasification of coal in a slag melt. An analysis was also performed on the combustion of fuel carbon in the melt. Methane dissociation and syngas formation on Ru, 00103226 OS, Rh, Ir, Pd, Pt, Cu, Ag, and Au: A theoretical study Au, C. T. PI al. J. Cnrcrl., 1999. 185, (I), 12-22. This paper presents a theoretical study of CHI dissociation and syngas formation on the title transition metals. The metal surface is simulated by an Mttt cluster model. Reaction energies for the steps involved are determined. The activation energies were estimated using the analytic BOC-MP formula. The dissociation energy is an important factor determining the catalytic activity of the metal. The order of the calculated total dissociation energies (CH+ + C, + 4H,) is consistent with the order of CH4 conversions over the metals. In the presence of adsorbed Oz, oxygen at metal surface sites promotes CHI dehydrogenation whereas oxygen at hollow sites promotes CHI dehydrogenation on platinum, copper, silver and gold, but shows no such effect on the other metals. The difference in the Hz selectivities was associated with the difference in the stabilities of OH on the metals. The calculated combination energies for CH, couplings agreed with experimental observations. 00103227 Methane partial oxidation over NiOlMgO solid solution catalysts Ruckenstein, E. and Hang Hu, Y. A&. Ccl/n/., A. 1999, 183, (I), 85-92. Three issues regarding the partial oxidation of methane to synthesis gas, over NiO/MgO solid solution catalysts. at a verg high space velocity of the feed gas (CHJOz = 211, GHSV = 720,000 cm igh), were investigated: (1) the effect of the solid solution formation between nickel oxide and magnesium oxide on the reaction; (2) the effect of the compound of the catalyst; and (3) the reaction mechanism. It was found that the mechanism mixtures of nickel oxide and magnesium oxide have low activity and selectivity; however, their activity and selectivity became higher with increasing calcination time, due to the formation of a NiO-MgO solid solution. In contrast, the solid solution catalysts prepared via impregnation provided high activity and selectivity, as well as high stability over a large range of nickel oxide concentrations. However, the activity was low for too low concentrations of NiO in NiO/MgO and the catalyst was no longer stable for too high concentrations of NiO. By comparing, under the same reaction conditions, the rate of partial oxidation of methane for CH4/02 = 2/I to that of the reforming reaction of a mixture. CHJHzOICOz obtained from the former by complete combustion, one could conclude that the pyrolysis mechanism was dominant at 700” and 750” but at 850”, the combustion reforming mechanism also played a part. Method and device for preparation of synthetic gas 00103226 Rennebeck, K. Ger. Offen. DE 19,908,863 (Cl. C25B1/02), 2 Sep 1999, DE Appl. 19,808,411, 1 Mar 1998. 8. (In German) A method is described for the preparation of synthetic gas by electrolysis with applications of textile hollow microfibers. The inner and outer walls of these microfibers could be used as anodes and cathodes, respectively. The end part of microfibers were connected to the frame. Modeling of gasification of the solid product of 00103229 thermolysis of slightly metamorphosed coals. Determination of optimum process parameters Shul’ga, I. V. er al. Koks Khm., 1999, 6, S-12. (In Russian) The development of thermolysis technology and the planned construction of an experimental gasification plant (10,000 t coal/year) for the solid product of thermolysis required modelling of the gasification using the existing laboratory equipment. More accurate basic parameters for the gasification plant were obtained: 3000 m3 air/t thermolysis solid product (P); 700 kg steam/t P; 250 min residence time; SOO-900°C reaction temperature in the case of using the gas for power generation; and 9001000°C reaction temperature in the case of using the gas in chemical synthesis. Partial oxidation of methane on supported nickel 00/03230 catalysts Ito, M. cl rtl. J. Chem. Eng Jpn., 1999, 32. (3), 274-279. In the partial oxidation of methane (POM) reaction several nickel catalysts are used which show high activities in carbon dioxide reforming of methane. Temperature programmed reaction and thermogravimetric analysis show that a reduced state of nickel is required to start the POM reaction, and that carbonaceous deposition occurs on alumina with high nickel contents, The temperature profile of the catalyst bed during the POM reaction suggests that this reaction consists of two consecutive reactions; methane combustion, following by reforming reactions (with steam and carbon dioxide). The heat caused from methane combustion keeps the temperature htgh enough to progress the reforming reactions, To suppress the carbon deposition, which causes catalytic deactivation and plugging of the reactor,
364
Fuel and Energy Abstracts
November 2000
carbon deposition-removal (D-R) treatment is applied in the POM reaction. On the basis of the hypothesis that active cores forming carbon whiskers are different from surface active sites for the main reaction, this treatment has been proposed to only remove or deactivate the former core nickel and makes the catalyst inactive for carbon deposition with only a small influence on the main reaction activity. 00103231 Partial oxidation of methane to synthesis gas over MgO- and SiO+upported rhodium catalysts Wang, H. Y. and Ruckenstein, E. J. Curd., 1999, 186, (1) 181-187. An investigation into the partial oxidation of methane over MgO- and SiOzsupported rhodium catalysts was carried out using a CH4/Oz mixture with a molar ratio of 2.111 as feed gas. At 750°C and atmospheric pressure, the 1% RhiMgO catalyst exhibited a, very high stability at the high gas hourly space velocity of 720,000 ml g hi , its catalytic activity and selectivity remaining constant and high after an induction time up to 100 h of reaction. In contrast, the 1% Rh/SiOz catalyst deactivated rapidly. To explain the above results, the reaction behaviours of CHI and CHI and CH.+/Oz (2/l) over the oxidized catalysts 1% Rh(O)/MgO and 1% Rh(O)/SiOz were studied in a pulse microreactor. No carbon deposition occurred during the reaction of CH4 with the MgO-supported rhodium catalyst, even after the catalyst was almost completely reduced. In contrast, a notable amount of surface carbon was generated during the reaction of CHd with the SiOasupported rhodium catalyst. During the reaction of CH,/Oz (2/l) over the oxidized catalysts, the rhodium oxide supported on SiOz was easily reduced by CH4, while the reduction of rhodium oxide supported on MgO occurred with some difficulty. This implies much stronger interactions between rhodium oxide and MgO than between the former and SiOa. Temperatureprogrammed reduction experiments also revealed much stronger interactions between rhodium and magnesium oxide and that two kinds of rhodium compounds were present in the oxidized MgO-supported rhodium catalyst. X-ray powder diffraction enabled the identification of RHzOs and MgRHz04 in pre-calcined 10% Rh(O)/SiOz and 10% Rh(O)/MgO, respectively. It is suggested that the high stability of the MgO-supported rhodium catalysts is due to the strong interactions between rhodium and magnesium oxide (especially the formation of MgRH,O,). 00103232 Product distribution from Yallourn coal by methane microwave plasma conversion Kamei, 0. er al. Sckiyu Gokkrrd~i, 1999, 42, (5), 335-341. The develo ment of a direct conversion technology of brown coal into important Puels, residues of upgraded carbon content and raw material gases, with the aid of methane microwave plasma. An examination was performed on the changes over time of the carbon, hydrogen and oxygen content of each of the Yallourn coal products. Dried coal was packed in the middle of a cylindrical quartz tube reactor of 25.0 mm inside diameter and 400 mm length. The following results were obtained. (1) Carbon and hydrogen from methane were converted into gaseous products (primarily acetylene and hydrogen). (2) Within 2 min of reaction, coal carbon was converted to oily products consisting mainly of aliphatic hydrocarbons in the hydrogen/carbon ratio range from 1.5 to 1.6; however, after 5 min of the reaction, it was converted to carbon dioxide. (3) Almost all of the oxygen in coal was converted to gaseous products (finally as carbon monoxide) via disintegration of the carboxyl groups and homogeneous transformation of the carbon dioxide produced. 00103233 Promoted reactivity of char in co-gasification of biomass and coal: synergies in the thermochemical process Sjostrom, K. rr ~rl. Fuel, 1999, 78, (IO), 1189-l 194. An experimental study on co-gasification of woody biomass and coal in oxygen-containing atmosphere was carried out in a pressurized fluidized bed reactor. The wood used was birch from a Swedish paper mill, while the coals used were Daw Mill coal of UK origin and a bituminous coal from Poland. The operation temperatures were 900 and 7Oo”C, and the pressure was 0.4 MPa. The ratio of coal to wood was varied in the investigation. The study was focused on possible synergetic effects in the thermochemical treatment of the fuels. The char formed was examined. The tar produced in the process was analysed. The nitrogen compounds emitted were detected. A noticeable phenomenon was that the mixtures of the fuels and their char formed Nt sim demonstrated an unexpected high reaction rate of gasification under the studied conditions. The yield of char diminished and consequently the production of gas increased. Furthermore, both the formations of tar and nitrogen compounds also seemed affected synergetically in the co-gasification experiments of the fuels. The yields of tar and of ammonia were lower than expected. 00103234 Recovery and upgrading of bitumen from tar sands Jones, M. E. C Can. Pat. Appl. CA 2,207,536 (Cl. COlB3/00), 11 Dee 1998, Appl. 2,207,536, 11 Jun 1997. 8. In the manufacture of synthesis gas from sulfur-free hot coke made by lime treatment, the process comprises contacting the hot coke with super steam to produce synthesis gas high in hydrogen content. The heat is then transferred to water tubes for the production of steam used in synthesis gas production, and the synthesis gas is recovered, compressed and discharged to gas heaters. When the hot gases from the gas heaters discharge, by compressors, into horizontal oil wells at desirable temperatures and pressures, the synthesis gases mobilize the bitumen for recovery by solvent and heat, and the oil produced is transferred to the upgrader. Tar-sand
of possible applicattons for the gasifier are mentioned including as an example a simple and compact system for the co-firing of biomass and waste in power plants. Mathematical modeling of air bubbling processes 00103225 during coal gasification in a slag melt Shaforost, D. A. and Madoyan, A. A. Tcplornergerika (MoscowJ. 1999, 4, 66-69. (In Russian) This paper presents a model of the air bubbling process that occurs during the gasification of coal in a slag melt. An analysis was also performed on the combustion of fuel carbon in the melt. Methane dissociation and syngas formation on Ru, 00103226 OS, Rh, Ir, Pd, Pt, Cu, Ag, and Au: A theoretical study Au, C. T. PI al. J. Cnrcrl., 1999. 185, (I), 12-22. This paper presents a theoretical study of CHI dissociation and syngas formation on the title transition metals. The metal surface is simulated by an Mttt cluster model. Reaction energies for the steps involved are determined. The activation energies were estimated using the analytic BOC-MP formula. The dissociation energy is an important factor determining the catalytic activity of the metal. The order of the calculated total dissociation energies (CH+ + C, + 4H,) is consistent with the order of CH4 conversions over the metals. In the presence of adsorbed Oz, oxygen at metal surface sites promotes CHI dehydrogenation whereas oxygen at hollow sites promotes CHI dehydrogenation on platinum, copper, silver and gold, but shows no such effect on the other metals. The difference in the Hz selectivities was associated with the difference in the stabilities of OH on the metals. The calculated combination energies for CH, couplings agreed with experimental observations. 00103227 Methane partial oxidation over NiOlMgO solid solution catalysts Ruckenstein, E. and Hang Hu, Y. A&. Ccl/n/., A. 1999, 183, (I), 85-92. Three issues regarding the partial oxidation of methane to synthesis gas, over NiO/MgO solid solution catalysts. at a verg high space velocity of the feed gas (CHJOz = 211, GHSV = 720,000 cm igh), were investigated: (1) the effect of the solid solution formation between nickel oxide and magnesium oxide on the reaction; (2) the effect of the compound of the catalyst; and (3) the reaction mechanism. It was found that the mechanism mixtures of nickel oxide and magnesium oxide have low activity and selectivity; however, their activity and selectivity became higher with increasing calcination time, due to the formation of a NiO-MgO solid solution. In contrast, the solid solution catalysts prepared via impregnation provided high activity and selectivity, as well as high stability over a large range of nickel oxide concentrations. However, the activity was low for too low concentrations of NiO in NiO/MgO and the catalyst was no longer stable for too high concentrations of NiO. By comparing, under the same reaction conditions, the rate of partial oxidation of methane for CH4/02 = 2/I to that of the reforming reaction of a mixture. CHJHzOICOz obtained from the former by complete combustion, one could conclude that the pyrolysis mechanism was dominant at 700” and 750” but at 850”, the combustion reforming mechanism also played a part. Method and device for preparation of synthetic gas 00103226 Rennebeck, K. Ger. Offen. DE 19,908,863 (Cl. C25B1/02), 2 Sep 1999, DE Appl. 19,808,411, 1 Mar 1998. 8. (In German) A method is described for the preparation of synthetic gas by electrolysis with applications of textile hollow microfibers. The inner and outer walls of these microfibers could be used as anodes and cathodes, respectively. The end part of microfibers were connected to the frame. Modeling of gasification of the solid product of 00103229 thermolysis of slightly metamorphosed coals. Determination of optimum process parameters Shul’ga, I. V. er al. Koks Khm., 1999, 6, S-12. (In Russian) The development of thermolysis technology and the planned construction of an experimental gasification plant (10,000 t coal/year) for the solid product of thermolysis required modelling of the gasification using the existing laboratory equipment. More accurate basic parameters for the gasification plant were obtained: 3000 m3 air/t thermolysis solid product (P); 700 kg steam/t P; 250 min residence time; SOO-900°C reaction temperature in the case of using the gas for power generation; and 9001000°C reaction temperature in the case of using the gas in chemical synthesis. Partial oxidation of methane on supported nickel 00/03230 catalysts Ito, M. cl rtl. J. Chem. Eng Jpn., 1999, 32. (3), 274-279. In the partial oxidation of methane (POM) reaction several nickel catalysts are used which show high activities in carbon dioxide reforming of methane. Temperature programmed reaction and thermogravimetric analysis show that a reduced state of nickel is required to start the POM reaction, and that carbonaceous deposition occurs on alumina with high nickel contents, The temperature profile of the catalyst bed during the POM reaction suggests that this reaction consists of two consecutive reactions; methane combustion, following by reforming reactions (with steam and carbon dioxide). The heat caused from methane combustion keeps the temperature htgh enough to progress the reforming reactions, To suppress the carbon deposition, which causes catalytic deactivation and plugging of the reactor,
364
Fuel and Energy Abstracts
November 2000
carbon deposition-removal (D-R) treatment is applied in the POM reaction. On the basis of the hypothesis that active cores forming carbon whiskers are different from surface active sites for the main reaction, this treatment has been proposed to only remove or deactivate the former core nickel and makes the catalyst inactive for carbon deposition with only a small influence on the main reaction activity. 00103231 Partial oxidation of methane to synthesis gas over MgO- and SiO+upported rhodium catalysts Wang, H. Y. and Ruckenstein, E. J. Curd., 1999, 186, (1) 181-187. An investigation into the partial oxidation of methane over MgO- and SiOzsupported rhodium catalysts was carried out using a CH4/Oz mixture with a molar ratio of 2.111 as feed gas. At 750°C and atmospheric pressure, the 1% RhiMgO catalyst exhibited a, very high stability at the high gas hourly space velocity of 720,000 ml g hi , its catalytic activity and selectivity remaining constant and high after an induction time up to 100 h of reaction. In contrast, the 1% Rh/SiOz catalyst deactivated rapidly. To explain the above results, the reaction behaviours of CHI and CHI and CH.+/Oz (2/l) over the oxidized catalysts 1% Rh(O)/MgO and 1% Rh(O)/SiOz were studied in a pulse microreactor. No carbon deposition occurred during the reaction of CH4 with the MgO-supported rhodium catalyst, even after the catalyst was almost completely reduced. In contrast, a notable amount of surface carbon was generated during the reaction of CHd with the SiOasupported rhodium catalyst. During the reaction of CH,/Oz (2/l) over the oxidized catalysts, the rhodium oxide supported on SiOz was easily reduced by CH4, while the reduction of rhodium oxide supported on MgO occurred with some difficulty. This implies much stronger interactions between rhodium oxide and MgO than between the former and SiOa. Temperatureprogrammed reduction experiments also revealed much stronger interactions between rhodium and magnesium oxide and that two kinds of rhodium compounds were present in the oxidized MgO-supported rhodium catalyst. X-ray powder diffraction enabled the identification of RHzOs and MgRHz04 in pre-calcined 10% Rh(O)/SiOz and 10% Rh(O)/MgO, respectively. It is suggested that the high stability of the MgO-supported rhodium catalysts is due to the strong interactions between rhodium and magnesium oxide (especially the formation of MgRH,O,). 00103232 Product distribution from Yallourn coal by methane microwave plasma conversion Kamei, 0. er al. Sckiyu Gokkrrd~i, 1999, 42, (5), 335-341. The develo ment of a direct conversion technology of brown coal into important Puels, residues of upgraded carbon content and raw material gases, with the aid of methane microwave plasma. An examination was performed on the changes over time of the carbon, hydrogen and oxygen content of each of the Yallourn coal products. Dried coal was packed in the middle of a cylindrical quartz tube reactor of 25.0 mm inside diameter and 400 mm length. The following results were obtained. (1) Carbon and hydrogen from methane were converted into gaseous products (primarily acetylene and hydrogen). (2) Within 2 min of reaction, coal carbon was converted to oily products consisting mainly of aliphatic hydrocarbons in the hydrogen/carbon ratio range from 1.5 to 1.6; however, after 5 min of the reaction, it was converted to carbon dioxide. (3) Almost all of the oxygen in coal was converted to gaseous products (finally as carbon monoxide) via disintegration of the carboxyl groups and homogeneous transformation of the carbon dioxide produced. 00103233 Promoted reactivity of char in co-gasification of biomass and coal: synergies in the thermochemical process Sjostrom, K. rr ~rl. Fuel, 1999, 78, (IO), 1189-l 194. An experimental study on co-gasification of woody biomass and coal in oxygen-containing atmosphere was carried out in a pressurized fluidized bed reactor. The wood used was birch from a Swedish paper mill, while the coals used were Daw Mill coal of UK origin and a bituminous coal from Poland. The operation temperatures were 900 and 7Oo”C, and the pressure was 0.4 MPa. The ratio of coal to wood was varied in the investigation. The study was focused on possible synergetic effects in the thermochemical treatment of the fuels. The char formed was examined. The tar produced in the process was analysed. The nitrogen compounds emitted were detected. A noticeable phenomenon was that the mixtures of the fuels and their char formed Nt sim demonstrated an unexpected high reaction rate of gasification under the studied conditions. The yield of char diminished and consequently the production of gas increased. Furthermore, both the formations of tar and nitrogen compounds also seemed affected synergetically in the co-gasification experiments of the fuels. The yields of tar and of ammonia were lower than expected. 00103234 Recovery and upgrading of bitumen from tar sands Jones, M. E. C Can. Pat. Appl. CA 2,207,536 (Cl. COlB3/00), 11 Dee 1998, Appl. 2,207,536, 11 Jun 1997. 8. In the manufacture of synthesis gas from sulfur-free hot coke made by lime treatment, the process comprises contacting the hot coke with super steam to produce synthesis gas high in hydrogen content. The heat is then transferred to water tubes for the production of steam used in synthesis gas production, and the synthesis gas is recovered, compressed and discharged to gas heaters. When the hot gases from the gas heaters discharge, by compressors, into horizontal oil wells at desirable temperatures and pressures, the synthesis gases mobilize the bitumen for recovery by solvent and heat, and the oil produced is transferred to the upgrader. Tar-sand