The two-phase volume-averaged model with the detailed chemistry reaction mechanism GRI 3.0 was adopted in the quasi-steady-state simulation of hydrogen production by CH4-rich filtration combustion in an alumina foam u...The two-phase volume-averaged model with the detailed chemistry reaction mechanism GRI 3.0 was adopted in the quasi-steady-state simulation of hydrogen production by CH4-rich filtration combustion in an alumina foam under fully developed conditions. The relations among the combustion wave velocity, the inlet gas velocity and the equivalence ratio were discussed, and their influences on the distributions of temperature and species in the alumina foam and on H2 yield, CH4 conversion, H2 selectivity and CO selectivity were analyzed in detail. The results show that the combustion wave velocity increases with the increase of equivalence ratio or inlet gas velocity. The H2 yield exceeded 50% with equivalence ratio between 2.0 and 3.0 and combustion wave velocity larger than 0.4 mm/s. The H2 selectivity exceeded 50% with equivalence ratio larger than 2.0 and CO selectivity exceeded 80% with equivalence ratio between 1.8 and 2.0 and combustion wave velocity larger than 0.4 mm/s.展开更多
Temperature-programmed simulation experiments of saturated hydrocarbons with calcium sulfate and element sulfur were compared in this study. Based on the variation analysis of the yields and evolvement features of gas...Temperature-programmed simulation experiments of saturated hydrocarbons with calcium sulfate and element sulfur were compared in this study. Based on the variation analysis of the yields and evolvement features of gaseous hydrocarbon (C1-C5) and inorganic gaseous CO2, H2 and H2S, the reaction mechanisms were analyzed and discussed. In the calcium sulfate-saturated hydrocarbon system, H2S was produced by a small quantity, which indicates this reaction belongs to the low-degreed thermal sulfate reduction (TSR) and is featured of self-pyrolysis. In the sulfur-saturated hydrocarbon system, the heated sulfur becomes sulfur radical, which has strong catalysis capability and can fasten the cracking of C―H bond in the alkyl group in the saturated hydrocarbons. As a result, the cracking of C―H bond leads to the yields enhancement of CO2 and H2, and at the same time, H2S was produced since the cracked hydrogen can be instantly combined with sulfur radical. Therefore, this reaction in the sulfur-hydrocarbon system belongs to the catalysis of sulfur radical. Furthermore, the promoted pyrolysis effects of C6+ hydrocarbons by sulfur radical in the low-temperature stage in the sul- fur-hydrocarbon system, together with the consumption effects of gaseous hydrocarbon in the high-temperature stage in the calcium-hydrocarbon system, result in the crossed phenomenon of the gaseous hydrocarbon yields curves.展开更多
From the chemical catalysis viewpoint,the excellent performance of CNTs in adsorption-activation of H2 and in promoting spillover of adsorbed H-species is very attractive,in addition to their nanosize channels,sp2-C c...From the chemical catalysis viewpoint,the excellent performance of CNTs in adsorption-activation of H2 and in promoting spillover of adsorbed H-species is very attractive,in addition to their nanosize channels,sp2-C constructed surfaces,and high thermal/electrical conductivity.This review examines some recent progresses of CNTs as a novel support or promoter of catalysts for certain hydrogenation or dehydrogenation reactions,e.g.,hydrogenation-conversion of syngas to yield alcohols and decomposition or steam-reforming of methanol to generate H2,mainly based on recent work carried out in our laboratory.展开更多
基金Supported by the China Postdoctoral Science Foundation (Grant No. 20080440713)the National Hi-Tech Research and Development Program ("863" Project) (Grant Nos. 2007AA05Z105, 2007AA05Z236)the National Natural Science Foundation of China (Grant No. 50776036)
文摘The two-phase volume-averaged model with the detailed chemistry reaction mechanism GRI 3.0 was adopted in the quasi-steady-state simulation of hydrogen production by CH4-rich filtration combustion in an alumina foam under fully developed conditions. The relations among the combustion wave velocity, the inlet gas velocity and the equivalence ratio were discussed, and their influences on the distributions of temperature and species in the alumina foam and on H2 yield, CH4 conversion, H2 selectivity and CO selectivity were analyzed in detail. The results show that the combustion wave velocity increases with the increase of equivalence ratio or inlet gas velocity. The H2 yield exceeded 50% with equivalence ratio between 2.0 and 3.0 and combustion wave velocity larger than 0.4 mm/s. The H2 selectivity exceeded 50% with equivalence ratio larger than 2.0 and CO selectivity exceeded 80% with equivalence ratio between 1.8 and 2.0 and combustion wave velocity larger than 0.4 mm/s.
基金Supported by National Basic Research Program of China (Grant No. 2006CB701404)CAS Innovation Project (Grant No. KZCX2-YW-114-1)+1 种基金National Natural Science Foundation of China (Grant No. 40873032)the Earmarked Fund of the State Key Laboratory of Organic Geochemistry (Grant No. SKLOG2008A01)
文摘Temperature-programmed simulation experiments of saturated hydrocarbons with calcium sulfate and element sulfur were compared in this study. Based on the variation analysis of the yields and evolvement features of gaseous hydrocarbon (C1-C5) and inorganic gaseous CO2, H2 and H2S, the reaction mechanisms were analyzed and discussed. In the calcium sulfate-saturated hydrocarbon system, H2S was produced by a small quantity, which indicates this reaction belongs to the low-degreed thermal sulfate reduction (TSR) and is featured of self-pyrolysis. In the sulfur-saturated hydrocarbon system, the heated sulfur becomes sulfur radical, which has strong catalysis capability and can fasten the cracking of C―H bond in the alkyl group in the saturated hydrocarbons. As a result, the cracking of C―H bond leads to the yields enhancement of CO2 and H2, and at the same time, H2S was produced since the cracked hydrogen can be instantly combined with sulfur radical. Therefore, this reaction in the sulfur-hydrocarbon system belongs to the catalysis of sulfur radical. Furthermore, the promoted pyrolysis effects of C6+ hydrocarbons by sulfur radical in the low-temperature stage in the sul- fur-hydrocarbon system, together with the consumption effects of gaseous hydrocarbon in the high-temperature stage in the calcium-hydrocarbon system, result in the crossed phenomenon of the gaseous hydrocarbon yields curves.
基金supported by the National Basic Research Program of China(2011CBA00508)the National Natural Science Foundation of China(20923004)the Program for Changjiang Scholars and Innovative Research Team in University(IRT1036)
文摘From the chemical catalysis viewpoint,the excellent performance of CNTs in adsorption-activation of H2 and in promoting spillover of adsorbed H-species is very attractive,in addition to their nanosize channels,sp2-C constructed surfaces,and high thermal/electrical conductivity.This review examines some recent progresses of CNTs as a novel support or promoter of catalysts for certain hydrogenation or dehydrogenation reactions,e.g.,hydrogenation-conversion of syngas to yield alcohols and decomposition or steam-reforming of methanol to generate H2,mainly based on recent work carried out in our laboratory.
