SDC-BCCF双相透氧膜材料的合成及透氧性能研究  

Synthesis and oxygen permeability of SDC-BCCF dual-phase oxygen permeable membrane materials

作　　者：苗强 夏鑫 杨微 李芳[1] 李其明[1] MIAO Qiang;XIA Xin;YANG Wei;LI Fang;LI Qiming(School of Chemistry,Chemical Engineering and Environmental Engineering, Liaoning Shihua University,Fushun 113001,China)

机构地区：[1]辽宁石油化工大学化学化工与环境学部,抚顺113001

出　　处：《膜科学与技术》2018年第4期75-80,85,共7页Membrane Science and Technology

基　　金：国家自然科学基金项目(21703091;21201096);辽宁省教育厅资助项目(L2010242);辽宁省教育厅重点实验室基础研究项目(LZ2015050);中国科学院煤制乙二醇及相关技术重点实验室资助项目

摘　　要：为了提高透氧膜材料的稳定性和透氧量,通过一锅法合成了Ce_(0.8)Sm_(0.2)O_(1.9)(50%,质量分数,下同)-BaCe_(0.1)Co_(0.3)Fe_(0.6)O_(3-δ)(50%)(SDC-BCCF)萤石-钙钛矿双相透氧膜材料,并系统考察了透氧温度、膜片厚度和氧分压梯度(吹扫气速率)对SDC-BCCF双相透氧膜透氧性能的影响.XRD表征表明,SDC萤石相和BCCF钙钛矿相可均匀相容于SDC-BCCF双相材料中,但是细微分析发现,材料中仍有微量BaCeO_3钙钛矿杂相的存在.SEM表征表明,在1 450℃焙烧条件下可以获得致密的SDC-BCCF双相透氧膜膜片.氧渗透实验表明,温度的升高、膜片厚度的下降以及吹扫气流速率的增加均有利于SDC-BCCF透氧膜透氧量的提升,其中0.5mm厚度的SDC-BCCF双相透氧膜片在950℃下透氧量可达到0.71mL/(min·cm2).通过对SDC-BCCF膜片速率控制步骤的考察可以发现,当SDC-BCCF膜片厚度大于或等于0.7mm时,透氧过程为体相扩散控制;当膜片厚度小于0.7mm时,透氧过程逐步转为表面交换控制.In order to improve the stability and oxygen flux of oxygen permeable membrane materials,Ce 0.8 Sm 0.2 O 1.9(50%)BaCe 0.1 Co 0.3 Fe 0.6 O 3-δ(50%)(SDC BCCF)fluorite-perovskite dual-phase oxygen permeable membrane materials were synthesized by one-spot method,and the effects of operation temperature,membrane thickness and oxygen partial pressure gradient(sweeping gas rate)on oxygen flux of SDC BCCF dual phase membranes were investigated.XRD patterns of SDC BCCF show that fluorite SDC and perovskite BCCF phases could be homogeneously mixed in SDC BCCF dual-phase materials.However,the refined XRD patterns reveal that trace mounts of perovskite BaCeO 3 impure phase can still be identified.SEM images show that the dense SDC BCCF dual-phase membrane disk can be obtained at 1 450℃.Oxygen permeation tests demonstrated that oxygen flux of SDC BCCF dual phase membranes can be improved by raising the temperature,reducing the membrane thickness and increasing the sweeping gas rate.It was found that the oxygen permeation flux can reach 0.71 mL/(min·cm 2)at 950℃for SDC BCCF membrane with a thickness of 0.5 mm.The rate-determining step of SDC BCCF dual-phase membranes was also checked in our experiment,which showed that the oxygen permeation for SDC BCCF dual-phase membrane was determined by bulk diffusion when the membrane thickness is more than or equal to 0.7 mm.However,while the membrane thickness was decreased to less than 0.7 mm,the oxygen permeation of SDC BCCF membranes transforms into the surface-exchange control.

关 键 词：双相透氧膜 钙钛矿 透氧量 体相扩散 表面交换 

分 类 号：TQ028.8[化学工程]