Oxygen permeation and partial oxidation of methane reaction in Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä oxygen permeation membrane

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• 作者：Shidong Song ; Peng Zhang ; Minfang Han ; Subhash C. Singhal
• 关键词：Oxygen permeation membrane ; Perovskite ; Mixed conductor ; Syngas ; Structural stability
• 刊名：Journal of Membrane Science
• 出版年：2012
• 出版时间：1 October, 2012
• 年：2012
• 卷：415-416
• 期：Complete
• 页码：654-662
• 全文大小：1234 K

文摘

Dense perovskite materials exhibiting mixed ionic and electronic conductivity can be used as a membrane material for the production of oxygen of very high purity and in partial oxidation of methane to syngas in membrane reactors. They represent an attractive technology which is energy- and cost-efficient in comparison with conventional technologies in those fields. Currently, one of the most promising membrane materials is BaCo_0.7Fe_0.2Nb_0.1O_3?¦Ä perovskite which possesses very high oxygen permeation flux. However, its stability is not satisfactorily high. In this work, Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä perovskite was prepared by introducing A-site deficiency into BaCo_0.7Fe_0.2Nb_0.1O_3?¦Ä and expected to enhance the stability and as well as the oxygen permeability. Under an air/helium oxygen gradient, the oxygen permeation flux of 1 mm thick Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane was 1.8 ml min^?1 cm^?2 at 875 ¡ãC, which is slightly higher than that of BaCo_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane under the similar condition. A 400 h durability test of Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane for POM reaction at 875 ¡ãC showed no degradation in the measured oxygen permeation flux and methane conversion, which indicated that Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä had a significantly better stability than BaCo_0.7Fe_0.2Nb_0.1O_3?¦Ä and could be a promising material for oxygen generator.