质子-电子导体陶瓷双相复合中空纤维催化膜与制氢膜反应器研究

Conventional high temperature proton conducting ceramic membranes (HTPCMs) generally exhibit low hydrogen permeability and/or low stability, and can be hardly used in practical applications. In this project, we propose to develop a novel dual-phase composite hollow fibre membranes of protonic and electronic conductors for catalytic dehydrogenation reaction. The details of the research work include: 1) to design and synthesize highly stabilized protonic conductor with high conductivity, with which a mixed proton-electron conducting ceramic membrane materials having high electrical conductivity and high stability will be obtained by combination with an electronic conducting oxide; 2) to fabricate asymmetric dual-phase composite hollow fibre hydrogen permeable membranes using a modified phase inversion-sintering technique, focusing on the formation and evolution of membrane microstructures; 3) to fabricate multi-functional catalytic membranes by impregnation of catalysts in the porous structure of the asymmetric hollow fibre membranes, with the catalytic activity and hydrogen permeability of the membranes improved by optimizing the preparation conditions; 4) to design and fabricate hollow fibre catalytic membrane reactors, with which the match of the membrane's catalytic activity with its separation property will be studied. The catalytic hollow fibre membrane reactor will be applied to the catalytic decomposition of ammonia for hydrogen production. The membrane reactor behavior will be investigated both theoretically and experimentally. After the project is finished, the relation of the composition and structure of the dual-phase composite membranes to their properties will be elucidated. The key techniques will be developed to fabricate dual-phase composite catalytic hollow fibre membranes with high hydrogen permeability, high catalytic activity towards dehydrogenation reactions and good stability. Furthermore, the optimal design of the hollow fibre membrane reactor and the operation conditions for the catalytic decomposition of ammonia for hydrogen production will be provided. The study will be able to provide both theoretical and technical supports for the development of new hydrogen permeable membrane materials and hydrogen production technology.

常规高温质子导体陶瓷膜氢通量低、稳定性差，难以实际应用。本申请拟研究开发一种新型质子-电子导体陶瓷双相复合中空纤维透氢膜及在催化制氢中的应用：1）设计合成质子电导率高、稳定性好的质子导体陶瓷电解质，通过与电子导体陶瓷复配制得具有高电导率和高稳定性的质子-电子混合导体陶瓷透氢膜材料；2）应用改进相转化-烧结技术制备非对称双相陶瓷复合中空纤维透氢膜，研究相转化成膜与膜结构控制机理；3）非对称中空纤维膜内催化剂负载制备多功能催化透氢膜，优化制备条件提高膜的催化及透氢性能；4）设计中空纤维催化膜反应器，研究催化膜反应器的反应-分离性能匹配及氨分解制氢行为规律。通过该课题研究，阐明双相陶瓷催化透氢膜组成-结构-性能间的关系，掌握制备透氢速率高、催化性能优良、稳定性好的双相陶瓷复合中空纤维催化膜的关键技术，优化氨分解制氢中空纤维膜反应器设计及操作条件，为开发新型透氢膜材料和制氢技术提供理论和技术支撑。

项目为解决质子/电子混合导体导电性能低、两种导电能力不匹配、膜厚度较大等导致的膜氢透量低，膜结构在含氢、二氧化碳等气氛中不稳定等问题，开展了材料组成的优化、膜结构的设计与制备工艺的优化以及膜组成-结构-性能间的关系等多方面的研究工作。1）采用溶胶低温燃烧法制备了多种陶瓷粉体，确定了以掺杂的CeO2为主的电子导电相材料。2）通过对相转化成型技术的优化发现铸膜液粘度与芯液组成之间的协同作用控制了膜的结构，高温烧结过程膜坯体经过了指状孔和海绵孔分别转变为致密膜中的指状多孔层与致密结构层的演变过程，通过一步相转化纺丝联合高温烧结制备了自支撑非对称结构的单层、双层中空纤维膜；设计制备了具有独立分布特征的片状双相致密陶瓷膜，克服了两种物相粒子之间的互相阻塞，使双相膜载流子的运动距离减半。3）致密陶瓷膜的透氢以及膜反应器性能研究发现掺杂、表面改性以及降低膜厚之间的协同作用能显著提高单相陶瓷膜的氢渗透通量、改善稳定性，单相非对称双层膜的氢渗透通量可达0.4 mL.min-1.cm-2，并且在含CO2的气氛中连续运行600 h 透氢量没有明显降低；电子导电相的引入以及膜厚度降低的协同作用可使双相膜的氢渗透通量与金属镍膜的透氢量相比拟、900℃双相非对称中空纤维膜的氢渗透通量达0.878 mL.min-1.cm-2；双相复合膜反应器中氨转化率可达到100%、CO2还原为一氧化碳的选择性提高到100%。课题研究成果公开发表SCI论文21篇其中8篇一区、12篇二区、1篇四区；获山东省自然科学二等奖1项；山东省高等学校科学技术奖自然科学三等奖一项；授权及申请发明专利11项；同时课题研究成果为致密陶瓷透氢膜材料的选择和制备、高性能膜的结构控制与制备、以及膜反应器的设计与制备提供了理论与技术支撑。