A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;fi...A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity evaluation.The results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.展开更多
This article illustrates the application of the ICR series lube oil isodewaxing catalysts in commercial scale and proposes the strategy on long cycle operation and optimization of catalysts. The results of commercial ...This article illustrates the application of the ICR series lube oil isodewaxing catalysts in commercial scale and proposes the strategy on long cycle operation and optimization of catalysts. The results of commercial application of the catalyst have revealed that the catalyst after pretreatment including drying, sulfidation and reduction can process VGO into base oils meeting the HVI II and HVI II+ standards, and can manufacture base oils meeting the HVI III standard after incorporating the filtrate oil or gatch from acetone-benzene solvent dewaxing unit. The nitrogen content of the feed oil to the IDW reactor should be controlled at 1.0—1.5 ppm, while the CO and CO2 contents in fresh hydrogen is strictly controlled to avoid poisoning of the IDW-HDF catalysts.展开更多
The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process ca...The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process can improve the catalytic activity with the change of high-valence Ni（Ni2O3,NiO） to low-valence Ni（Ni,NiO）.Among these catalysts after activation,the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds.After long-term experiment at 700°C and the S/C ratio of 9,the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil（mixed by the four compounds with the equal masses）.With CaO calcinated from calcium acetate as CO2 sorbent,the catalytic steam reforming experiment combined with continuous in situ CO2 adsorption was performed.With the comparison of the case without the adding of CO2 sorbent,the hydrogen concentration was dramatically improved from 74.8% to 92.3%,with the CO2 concentration obviously decreased from 19.90% to 1.88%.展开更多
Hydrogen was prepared via catalytic steam reforming of bio-oil which was obtained from fast pyrolysis of biomass in a fluidized bed reactor.Influential factors including temperature,weight hourly space velocity(WHSV) ...Hydrogen was prepared via catalytic steam reforming of bio-oil which was obtained from fast pyrolysis of biomass in a fluidized bed reactor.Influential factors including temperature,weight hourly space velocity(WHSV) of bio-oil,mass ratio of steam to bio-oil(S/B) as well as catalyst type on hydrogen selectivity and other desirable gas products were investigated.Based on hydrogen in stoichiometric potential and carbon balance in gaseous phase and feed,hydrogen yield and carbon selectivity were examined.The experimental results show that higher temperature favors the hydrogen selectivity by H2 mole fraction in gaseous products stream and it plays an important role in hydrogen yield and carbon selectivity.Higher hydrogen selectivity and yield,and carbon selectivity were obtained at lower bio-oil WHSV.In catalytic steam reforming system a maximum steam concentration value exists,at which hydrogen selectivity and yield,and carbon selectivity keep constant.Through experiments,preferential operation conditions were obtained as follows:temperature 800～850℃,bio-oil WHSV below 3.0 h-1,and mass ratio of steam to bio-oil 10～12.The performance tests indicate that Ni-based catalysts are optional,especially Ni/α-Al2O3 effective in the steam reforming process.展开更多
The present work explores the reaction pathways of γ-valerolactone(GVL) over a supported ruthenium catalyst. The conversion of GVL in aqueous phase over a 5% Ru/C catalyst was investigated in a batch reactor operatin...The present work explores the reaction pathways of γ-valerolactone(GVL) over a supported ruthenium catalyst. The conversion of GVL in aqueous phase over a 5% Ru/C catalyst was investigated in a batch reactor operating at 463 K under 500–1000 psi of H2. The main reaction products obtained under these conditions were 2-butanol(2-BuOH), 1,4-pentanediol(1,4-PDO), 2-methyltetrahydrofuran(2-MTHF) and 2-pentanol(2-PeOH). A complete reaction network was developed, identifying the primary and/or secondary products. In this reaction network, production of 2-BuOH via decarbonylation of a ring-opened surface intermediate CH3CH(O*)–(CH2)2–CO*is clearly the dominant pathway. From the evolution of products as a function of reaction time and theoretical(DFT) calculations, a mechanism for the formation of intermediates and products is proposed. The high sensitivity of 2-BuOH production to the presence of CO, compared to a much lower effect on the production of the other products indicates that the sites responsible for decarbonylation are particularly prone to CO adsorption and poisoning. Also, since the decarbonylation rate is not affected by the H2 pressure it is concluded that the direct decarbonylation path of the CH3CH(O*)–(CH2)2–CO*intermediate does not required a previous dehydrogenation step, as is the case in decarbonylation of short alcohols.展开更多
基金the financial support from the Sinopec Catalyst Co.Ltd.,China。
文摘A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity evaluation.The results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.
文摘This article illustrates the application of the ICR series lube oil isodewaxing catalysts in commercial scale and proposes the strategy on long cycle operation and optimization of catalysts. The results of commercial application of the catalyst have revealed that the catalyst after pretreatment including drying, sulfidation and reduction can process VGO into base oils meeting the HVI II and HVI II+ standards, and can manufacture base oils meeting the HVI III standard after incorporating the filtrate oil or gatch from acetone-benzene solvent dewaxing unit. The nitrogen content of the feed oil to the IDW reactor should be controlled at 1.0—1.5 ppm, while the CO and CO2 contents in fresh hydrogen is strictly controlled to avoid poisoning of the IDW-HDF catalysts.
基金supported by the National Natural Science Foundation of China(No.51274066,51304048)the National Key Technology R&D Program of China(No.2013BAA03B03)the National Science Foundation for Post-doctoral Scientists of China(No.2013M541240)
文摘The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process can improve the catalytic activity with the change of high-valence Ni（Ni2O3,NiO） to low-valence Ni（Ni,NiO）.Among these catalysts after activation,the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds.After long-term experiment at 700°C and the S/C ratio of 9,the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil（mixed by the four compounds with the equal masses）.With CaO calcinated from calcium acetate as CO2 sorbent,the catalytic steam reforming experiment combined with continuous in situ CO2 adsorption was performed.With the comparison of the case without the adding of CO2 sorbent,the hydrogen concentration was dramatically improved from 74.8% to 92.3%,with the CO2 concentration obviously decreased from 19.90% to 1.88%.
基金Supported by Research Program Foundation of Science and Technology Commission of Shanghai Municipality (No041612002)
文摘Hydrogen was prepared via catalytic steam reforming of bio-oil which was obtained from fast pyrolysis of biomass in a fluidized bed reactor.Influential factors including temperature,weight hourly space velocity(WHSV) of bio-oil,mass ratio of steam to bio-oil(S/B) as well as catalyst type on hydrogen selectivity and other desirable gas products were investigated.Based on hydrogen in stoichiometric potential and carbon balance in gaseous phase and feed,hydrogen yield and carbon selectivity were examined.The experimental results show that higher temperature favors the hydrogen selectivity by H2 mole fraction in gaseous products stream and it plays an important role in hydrogen yield and carbon selectivity.Higher hydrogen selectivity and yield,and carbon selectivity were obtained at lower bio-oil WHSV.In catalytic steam reforming system a maximum steam concentration value exists,at which hydrogen selectivity and yield,and carbon selectivity keep constant.Through experiments,preferential operation conditions were obtained as follows:temperature 800～850℃,bio-oil WHSV below 3.0 h-1,and mass ratio of steam to bio-oil 10～12.The performance tests indicate that Ni-based catalysts are optional,especially Ni/α-Al2O3 effective in the steam reforming process.
基金the Department of Energy for funding the experimental part of this work under grant DE-SC0004600the theoretical part under grant DE-EE0006287 of the Bioenergy Technology Office CHASE program
文摘The present work explores the reaction pathways of γ-valerolactone(GVL) over a supported ruthenium catalyst. The conversion of GVL in aqueous phase over a 5% Ru/C catalyst was investigated in a batch reactor operating at 463 K under 500–1000 psi of H2. The main reaction products obtained under these conditions were 2-butanol(2-BuOH), 1,4-pentanediol(1,4-PDO), 2-methyltetrahydrofuran(2-MTHF) and 2-pentanol(2-PeOH). A complete reaction network was developed, identifying the primary and/or secondary products. In this reaction network, production of 2-BuOH via decarbonylation of a ring-opened surface intermediate CH3CH(O*)–(CH2)2–CO*is clearly the dominant pathway. From the evolution of products as a function of reaction time and theoretical(DFT) calculations, a mechanism for the formation of intermediates and products is proposed. The high sensitivity of 2-BuOH production to the presence of CO, compared to a much lower effect on the production of the other products indicates that the sites responsible for decarbonylation are particularly prone to CO adsorption and poisoning. Also, since the decarbonylation rate is not affected by the H2 pressure it is concluded that the direct decarbonylation path of the CH3CH(O*)–(CH2)2–CO*intermediate does not required a previous dehydrogenation step, as is the case in decarbonylation of short alcohols.
