双相混合导体膜氧渗透性能改善的研究进展

双相混合导体膜在高温下能够同时传导氧离子和电子, 具有稳定性好、膨胀系数低、机械强度高和成分可调等优点, 可以作为反应器应用于甲烷部分氧化制合成气(POM)。但双相混合导体膜的透氧率较低, 成为亟待解决的问题。本文从透氧机理入手详细阐述了氧渗透过程的影响因素。在此基础上综述了目前提高双相混合导体膜透氧率的措施, 包括了采用混合导体作为电子导电相、降低电子导电相形成连续渗流网络的体积比阀值和减小双相晶粒尺寸, 以及宏观上制备出不对称膜、管状膜和中空纤维膜进一步降低膜厚、增大表面积以提高透氧率。最后指出双相混合导体膜在未来需要重点解决的一些问题。

Research Progress in Improvement of Oxygen Permeation Properties for Dual-phase Mixed Conducting Membranes

Dual-phase mixed conducting membrane can transport oxygen ions and electrons simultaneously at high temperature. Due to its high stability, low thermal expansion coefficient, high mechanical strength, and tunable component, it shows great potential in application of partial oxidation of methane to syngas (POM). However, how to improve its oxygen permeation flux is a key problem needing to be solved. In this review, the controlled step of the permeation process was analyzed based on the permeation mechanization. The improvements were presented, including utilized mixed conductor as electron conducting phase, reduced electronic threshold and decreased the grain size of the two phases. Meanwhile, fabricating asymmetric membrane, tube membrane and hollow fiber membrane were also efficient ways to reduce the thickness and to increase the surface area of the membrane, resulting in much increased permeation flux. Finally, some key problems to be solved in the future were also outlined.