Mixed-conducting oxygen permeable membranes represent a class of novel ceramic membranes, which exhibit mixed oxygen ionic and electronic conductivities. At high temperatures, oxygen can permeate through the membrane ...Mixed-conducting oxygen permeable membranes represent a class of novel ceramic membranes, which exhibit mixed oxygen ionic and electronic conductivities. At high temperatures, oxygen can permeate through the membrane from the high to low oxygen pressure side under an oxygen concentration gradient. Theoretically, the permselectivity of oxygen is 100%. Recently, anovel mixed-conducting membrane-Ba0.5Sr0.5Coo.8Feo.2O3-δ has been developed, which showsextremely high oxygen permeability and promising stability. Furthermore, the reactor made with such membranes was successfully applied to the partial oxidation of methane to syngas reaction using air as the oxygen source, which realized the coupling of the separation of oxygen from air and the partial oxidation of membrane reaction in one process. At 850℃, methane conversion 】 88%, CO selectivity 】97% and oxygen permeation rate of about 7.8 mL/(cm2 ·min) were obtained.展开更多
A dense Ba0.5Sr0.5Co0.8Fe0.2O3-δ membrane tube was prepared by the extruding method. Furthermore, a membrane reactor with this tubular membrane was successfully applied to partial oxidation of methane (POM) reaction,...A dense Ba0.5Sr0.5Co0.8Fe0.2O3-δ membrane tube was prepared by the extruding method. Furthermore, a membrane reactor with this tubular membrane was successfully applied to partial oxidation of methane (POM) reaction, in which the separation of oxygen from air and the partial oxidation of methane are integrated in one process. At 875°C, 94% of methane conversion, 98% of CO selectivity, 95% of H2 selectivity, and as high as 8.8 mL/(min·cm2) of oxygen flux were obtained. In POM reaction condition, the membrane tube shows a very good stability.展开更多
Hydrogen amplification from simulated hot coke oven gas （HCOG） was investigated in a BaCo0.7Fe0.2Nb0.1O3-δ （BCFNO） membrane reactor combined with a Ru-Ni/Mg（Al）O catalyst by the partial oxidation of hydrocarbon...Hydrogen amplification from simulated hot coke oven gas （HCOG） was investigated in a BaCo0.7Fe0.2Nb0.1O3-δ （BCFNO） membrane reactor combined with a Ru-Ni/Mg（Al）O catalyst by the partial oxidation of hydrocarbon compounds under atmospheric pressure. Under optimized reaction conditions, the dense oxygen permeable membrane had an oxygen permeation flux around 13.3 ml/（cm^2·min）. By reforming of the toluene and methane, the amount of H2 in the reaction effluent gas was about 2 times more than that of original H2 in simulated HCOG. The Rn-Ni/Mg（Al）O catalyst used in the membrane reactor possessed good catalytic activity and resistance to coking. After the activity test, a small amount of whisker carbon was observed on the used catalyst, and most of them could be removed in the hydrogen-rich atmosphere, implying that the carbon deposition formed on the catalyst might be a reversible process.展开更多
The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ （M = Ni, Al and Zr） mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement....The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ （M = Ni, Al and Zr） mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement. The SrCo0.4Fe0.5M0.1O3-δ for M = Fe, Ni, Al and Zr were denoted as SCF, SCFN, SCFA and SCFZ, respectively. O2-TPD analysis revealed that the amount of α oxygen desorption decreased with increasing the valance of doped metal elements （SCFN 〉 SCFA SCF 〉 SCFZ）. The oxygen permeation flux at the temperature ≈igher than 1148 K decreased in the order of SCFN 〉 SCF 〉 SCFZ 〉 SCFA. Single activation for oxygen permeation was observed for SCFZ oxide and the activation energies of SCF and SCFA change at around 1073 K, while the change temoerature of SCFN was about 1173 K.展开更多
A novel zirconium-based membrane material of BaCo0.4Fe0.4Zr0.2O3-6 with cubic perovskite structure was synthesized for the first time through a method of citric and EDTA acid combined complexes. The structural stabili...A novel zirconium-based membrane material of BaCo0.4Fe0.4Zr0.2O3-6 with cubic perovskite structure was synthesized for the first time through a method of citric and EDTA acid combined complexes. The structural stability was characterized by XRD, O-2-TPD and H-2-TPR techniques respectively. The high oxygen permeation flux of 0.873 mL/cm(2) min at 950 degreesC was obtained under He/Air gradient. Meanwhile, the single activation energy for oxygen permeation and the long-term steady operation of 200 h at 800 degreesC were achieved.展开更多
According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe...According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe0.5Zr0.1O3-δ oxide-based membranes were systematically compared in terms of oxygen permeability and chemical stability,and their differences were elucidated by means of the theoretical calculation.For the oxygen permeability,the asymmetric membrane was greater than the symmetric membrane due to the significant decrease of bulk diffusion resistance in the thin dense layer of the asymmetric membrane.In regard to the chemical stability,the increase of oxygen partial pressure on the asymmetric membrane surface at CH4 side produced the stable time of over 1032h in partial oxidation of methane at 1123K,while the symmetric membrane was only of 528h.This study demonstrated that the asymmetric membrane was a promising geometrical configuration for the practical application.展开更多
Dehydrogenation coupling of methane(DCM),which can be effectively used to produce low carbon alkenes,has the advantages of rich raw materials,simple reaction device,low energy consumption,etc.Herein,we report a series...Dehydrogenation coupling of methane(DCM),which can be effectively used to produce low carbon alkenes,has the advantages of rich raw materials,simple reaction device,low energy consumption,etc.Herein,we report a series of Co doped perovskite porous-dense BaCe_(0.9)Y_(0.1)Co_(x)O_(3-δ)(BCYCx)membrane for DCM.After treatment in a reduced atmosphere,a large number of Co nanoparticles will exsolute on the surface of BCY.The metal-oxide interface is helpful to activate the C–H bonds,inhibit the carbon deposition,and so on.The XRD,SEM and XPS prove that Co nanoparticles homogeneously distributed on the BCYCx porous layers,which will create a large quantity of catalytic active sites.At 1100℃,the highest concentration of C_(2)product was 5.66%(5.25%ethane+0.41%ethylene)in output gas when methane conversion reaches a maximum value of 24.8%,and the C_(2)selectivity gets to 45.6%.We further demonstrate the catalytic performance of high-temperature DCM without obvious decrease after running for 30 hours.展开更多
采用干湿法纺丝技术制备Sr0.7Ba0.3Fe0.9Mo0.1O3-δ(SBFM)中空纤维支撑体,以Nb2O5掺杂的Sr Co0.8Fe0.2O3-δ(SCFNb)为膜材料,采用旋转喷涂结合共烧结技术制备出担载型SCFNb/SBFM中空纤维氧渗透膜。借助于XRD、SEM、热膨胀分析、透氧及...采用干湿法纺丝技术制备Sr0.7Ba0.3Fe0.9Mo0.1O3-δ(SBFM)中空纤维支撑体,以Nb2O5掺杂的Sr Co0.8Fe0.2O3-δ(SCFNb)为膜材料,采用旋转喷涂结合共烧结技术制备出担载型SCFNb/SBFM中空纤维氧渗透膜。借助于XRD、SEM、热膨胀分析、透氧及膜反应性能测试等手段,分别对样品的晶相结构、膜微观结构、支撑体与膜层的烧结行为、膜的氧渗透通量及膜反应性能进行了研究。结果表明,膜层与支撑体的晶相结构仍保持钙钛矿主体相。支撑体具有单一海绵孔/指状孔结构,膜厚为5?m且致密无缺陷,膜层与支撑体结合良好。在900℃时,氧渗透通量达到0.74 m L/(cm2·min)。850℃下甲烷部分氧化膜反应稳定操作超过200 h,稳态下氧渗透通量为4.5 m L/(cm2·min)。研究表明,担载型SCFNb/SBFM中空纤维氧渗透膜具有较高的氧渗透通量,同时具有良好的膜反应稳定性。展开更多
文摘Mixed-conducting oxygen permeable membranes represent a class of novel ceramic membranes, which exhibit mixed oxygen ionic and electronic conductivities. At high temperatures, oxygen can permeate through the membrane from the high to low oxygen pressure side under an oxygen concentration gradient. Theoretically, the permselectivity of oxygen is 100%. Recently, anovel mixed-conducting membrane-Ba0.5Sr0.5Coo.8Feo.2O3-δ has been developed, which showsextremely high oxygen permeability and promising stability. Furthermore, the reactor made with such membranes was successfully applied to the partial oxidation of methane to syngas reaction using air as the oxygen source, which realized the coupling of the separation of oxygen from air and the partial oxidation of membrane reaction in one process. At 850℃, methane conversion 】 88%, CO selectivity 】97% and oxygen permeation rate of about 7.8 mL/(cm2 ·min) were obtained.
基金This work was supported by the National High Technology Research and Development Program (Grant No. 715-006-0122)the "973" Project of the Ministry of Science and Technology, China (Grant No. G1999022401).
文摘A dense Ba0.5Sr0.5Co0.8Fe0.2O3-δ membrane tube was prepared by the extruding method. Furthermore, a membrane reactor with this tubular membrane was successfully applied to partial oxidation of methane (POM) reaction, in which the separation of oxygen from air and the partial oxidation of methane are integrated in one process. At 875°C, 94% of methane conversion, 98% of CO selectivity, 95% of H2 selectivity, and as high as 8.8 mL/(min·cm2) of oxygen flux were obtained. In POM reaction condition, the membrane tube shows a very good stability.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2006AA11A189)Science and Technology Commission of Shanghai Municipality (Grant Nos. 0952NM01400 and 07DZ12036)
文摘Hydrogen amplification from simulated hot coke oven gas （HCOG） was investigated in a BaCo0.7Fe0.2Nb0.1O3-δ （BCFNO） membrane reactor combined with a Ru-Ni/Mg（Al）O catalyst by the partial oxidation of hydrocarbon compounds under atmospheric pressure. Under optimized reaction conditions, the dense oxygen permeable membrane had an oxygen permeation flux around 13.3 ml/（cm^2·min）. By reforming of the toluene and methane, the amount of H2 in the reaction effluent gas was about 2 times more than that of original H2 in simulated HCOG. The Rn-Ni/Mg（Al）O catalyst used in the membrane reactor possessed good catalytic activity and resistance to coking. After the activity test, a small amount of whisker carbon was observed on the used catalyst, and most of them could be removed in the hydrogen-rich atmosphere, implying that the carbon deposition formed on the catalyst might be a reversible process.
基金This work is sponsored by the National Basic Research Program of China （No. 2003CB615702）；National Natural Science Foundation of China （No. 20576051, 20636020）；Special Research Foundation for Doctoral Discipline of Higher Education （No. 20060291003）.
文摘The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ （M = Ni, Al and Zr） mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement. The SrCo0.4Fe0.5M0.1O3-δ for M = Fe, Ni, Al and Zr were denoted as SCF, SCFN, SCFA and SCFZ, respectively. O2-TPD analysis revealed that the amount of α oxygen desorption decreased with increasing the valance of doped metal elements （SCFN 〉 SCFA SCF 〉 SCFZ）. The oxygen permeation flux at the temperature ≈igher than 1148 K decreased in the order of SCFN 〉 SCF 〉 SCFZ 〉 SCFA. Single activation for oxygen permeation was observed for SCFZ oxide and the activation energies of SCF and SCFA change at around 1073 K, while the change temoerature of SCFN was about 1173 K.
基金This work was supported by the National Advanced Materials Committee(Grant No.715-006-0122)the Ministry of Science and Technology of China(G1999022401)the National Natural Science Foundation of China(Grant No.59789201).
文摘A novel zirconium-based membrane material of BaCo0.4Fe0.4Zr0.2O3-6 with cubic perovskite structure was synthesized for the first time through a method of citric and EDTA acid combined complexes. The structural stability was characterized by XRD, O-2-TPD and H-2-TPR techniques respectively. The high oxygen permeation flux of 0.873 mL/cm(2) min at 950 degreesC was obtained under He/Air gradient. Meanwhile, the single activation energy for oxygen permeation and the long-term steady operation of 200 h at 800 degreesC were achieved.
基金Supported by the National Basic Research Program of China （2009CB623406）, the National Natural Science Foundation of China （20636020）, the National High Technology Research and Development Program of China （2006AA030204） and the Specialized Research Fund for the Doctoral Program of Higher Education of China （20060291003）.
文摘According to the configuration,mixed-conducting membranes are classified as symmetric membranes and asymmetric membranes consisting of a thin dense layer and a porous support.In this study,these two kinds of SrCo0.4Fe0.5Zr0.1O3-δ oxide-based membranes were systematically compared in terms of oxygen permeability and chemical stability,and their differences were elucidated by means of the theoretical calculation.For the oxygen permeability,the asymmetric membrane was greater than the symmetric membrane due to the significant decrease of bulk diffusion resistance in the thin dense layer of the asymmetric membrane.In regard to the chemical stability,the increase of oxygen partial pressure on the asymmetric membrane surface at CH4 side produced the stable time of over 1032h in partial oxidation of methane at 1123K,while the symmetric membrane was only of 528h.This study demonstrated that the asymmetric membrane was a promising geometrical configuration for the practical application.
基金the National Key Research and Development Program of China(2017YFA0700102)Natural Science Foundation of China(91845202)+1 种基金Dalian National Laboratory for Clean Energy(DNL180404)Strategic Priority Research Program of Chinese Academy of Sciences(XDB2000000)。
文摘Dehydrogenation coupling of methane(DCM),which can be effectively used to produce low carbon alkenes,has the advantages of rich raw materials,simple reaction device,low energy consumption,etc.Herein,we report a series of Co doped perovskite porous-dense BaCe_(0.9)Y_(0.1)Co_(x)O_(3-δ)(BCYCx)membrane for DCM.After treatment in a reduced atmosphere,a large number of Co nanoparticles will exsolute on the surface of BCY.The metal-oxide interface is helpful to activate the C–H bonds,inhibit the carbon deposition,and so on.The XRD,SEM and XPS prove that Co nanoparticles homogeneously distributed on the BCYCx porous layers,which will create a large quantity of catalytic active sites.At 1100℃,the highest concentration of C_(2)product was 5.66%(5.25%ethane+0.41%ethylene)in output gas when methane conversion reaches a maximum value of 24.8%,and the C_(2)selectivity gets to 45.6%.We further demonstrate the catalytic performance of high-temperature DCM without obvious decrease after running for 30 hours.
文摘采用干湿法纺丝技术制备Sr0.7Ba0.3Fe0.9Mo0.1O3-δ(SBFM)中空纤维支撑体,以Nb2O5掺杂的Sr Co0.8Fe0.2O3-δ(SCFNb)为膜材料,采用旋转喷涂结合共烧结技术制备出担载型SCFNb/SBFM中空纤维氧渗透膜。借助于XRD、SEM、热膨胀分析、透氧及膜反应性能测试等手段,分别对样品的晶相结构、膜微观结构、支撑体与膜层的烧结行为、膜的氧渗透通量及膜反应性能进行了研究。结果表明,膜层与支撑体的晶相结构仍保持钙钛矿主体相。支撑体具有单一海绵孔/指状孔结构,膜厚为5?m且致密无缺陷,膜层与支撑体结合良好。在900℃时,氧渗透通量达到0.74 m L/(cm2·min)。850℃下甲烷部分氧化膜反应稳定操作超过200 h,稳态下氧渗透通量为4.5 m L/(cm2·min)。研究表明,担载型SCFNb/SBFM中空纤维氧渗透膜具有较高的氧渗透通量,同时具有良好的膜反应稳定性。
