We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst comp...We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni2O/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 ℃, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni2O/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.展开更多
Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of （Ca24Al28O64）^4＋·4O^-/Mg （C12A7-Mg）. The catalytic steam reforming was ...Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of （Ca24Al28O64）^4＋·4O^-/Mg （C12A7-Mg）. The catalytic steam reforming was investigated from 250 to 850℃ in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750℃, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.展开更多
This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming u...This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming units. This article also explores the technical measures for maximizing the target products delivered by the gasoline-type and aromatic-type CCR units with respect to the selection of catalysts, the optimization of feedstock and the optimized operating regime.展开更多
Autothermal steam reforming （ATR） of bio-oil, which couples the endothermic steam reform- ing reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effec...Autothermal steam reforming （ATR） of bio-oil, which couples the endothermic steam reform- ing reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effective production of hydrogen through ATR of bio-oil was performed at lower temperature with NiCuZnAl catalyst. The highest hydrogen yield from bio-oil reached 64.3% with a nearly complete bio-oil conversion at 600℃, the ratio of steam to carbon fed （S/C） of 3 and the oxygen to carbon ratio （O/C） of 0.34. The reaction conditions in ATR including temperature, O/C, S/C and weight hourly space velocity can be used to control both hydrogen yield and products distribution. The comparison between the ATR and common steam reforming of bio-oil was studied. The mechanism of the ATR of bio-oil was also discussed.展开更多
The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were ...The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were synthesized,with nickel loading of 8 wt%,using the incipient wetness,wet impregnation,and modified equilibrium deposition filtration methods.The catalysts＇ surface and bulk properties were determined by inductively coupled plasma（ICP）,N2 adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and temperature-programmed reduction（TPR）.Used catalysts were characterized by techniques such as elemental analysis and SEM in order to determine the level of carbon that was deposited and catalyst morphology.The results indicated that the synthesis method affected the textural,structural and surface properties of the catalysts,differentiating the dispersion and the kind of nickel species on alumina＇s surface.The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf catalyst was higher than in the other two catalysts,indicating that the nickel aluminate species of this catalyst were more reducible.Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selectivities and approximately constant CO selectivities for temperatures above 550℃,indicating that these catalysts successfully catalyze the water gas shift reaction.It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion,hydrogen yield,allyl alcohol,acetaldehyde,and acetic acid selectivities at 650℃ and the lowest carbon deposition of the catalysts tested.The correlation of the catalysts＇ structural properties,dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase＇s dispersion,that are easier to reduce,more active and selective to hydrogen production,and more resistant to carbon deposition.展开更多
基金ACKNOWLEDGMENTS This work is supported by the National High Tech Research and Development Program （No.2009AA05Z435）, the National Basic Research Program of Ministry of Science and Technology of China （No.2007CB210206）, and the General Program of the National Natural Science Foundation of China （No.50772107）.
文摘We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni2O/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 ℃, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni2O/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.
文摘Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of （Ca24Al28O64）^4＋·4O^-/Mg （C12A7-Mg）. The catalytic steam reforming was investigated from 250 to 850℃ in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750℃, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.
文摘This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming units. This article also explores the technical measures for maximizing the target products delivered by the gasoline-type and aromatic-type CCR units with respect to the selection of catalysts, the optimization of feedstock and the optimized operating regime.
文摘Autothermal steam reforming （ATR） of bio-oil, which couples the endothermic steam reform- ing reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effective production of hydrogen through ATR of bio-oil was performed at lower temperature with NiCuZnAl catalyst. The highest hydrogen yield from bio-oil reached 64.3% with a nearly complete bio-oil conversion at 600℃, the ratio of steam to carbon fed （S/C） of 3 and the oxygen to carbon ratio （O/C） of 0.34. The reaction conditions in ATR including temperature, O/C, S/C and weight hourly space velocity can be used to control both hydrogen yield and products distribution. The comparison between the ATR and common steam reforming of bio-oil was studied. The mechanism of the ATR of bio-oil was also discussed.
基金Financial support by the program THALIS implemented within the framework of Education and Lifelong Learning Operational Programmeco-financed by the Hellenic Ministry of Education,Lifelong Learning and Religious Affairs and the European Social Fund,for the project 'Production of Energy Carriers from Biomass by Productsfinancial support provided by the Committee of the Special Account for Research Funds of the Technological Educational Institute of Western Macedonia(ELKE,TEIWM)
文摘The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were synthesized,with nickel loading of 8 wt%,using the incipient wetness,wet impregnation,and modified equilibrium deposition filtration methods.The catalysts＇ surface and bulk properties were determined by inductively coupled plasma（ICP）,N2 adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and temperature-programmed reduction（TPR）.Used catalysts were characterized by techniques such as elemental analysis and SEM in order to determine the level of carbon that was deposited and catalyst morphology.The results indicated that the synthesis method affected the textural,structural and surface properties of the catalysts,differentiating the dispersion and the kind of nickel species on alumina＇s surface.The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf catalyst was higher than in the other two catalysts,indicating that the nickel aluminate species of this catalyst were more reducible.Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selectivities and approximately constant CO selectivities for temperatures above 550℃,indicating that these catalysts successfully catalyze the water gas shift reaction.It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion,hydrogen yield,allyl alcohol,acetaldehyde,and acetic acid selectivities at 650℃ and the lowest carbon deposition of the catalysts tested.The correlation of the catalysts＇ structural properties,dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase＇s dispersion,that are easier to reduce,more active and selective to hydrogen production,and more resistant to carbon deposition.
