贵金属分散多孔性氧化铝膜用于高温气体分离与反应  

Preparation of metal-dispersed alumina membrane for hydrogen selective separation and catalytic reaction by sol-gel method

作　　者：柴茂荣[1] 江口浩一[2] 荒井弘通 

机构地区：[1]大连理工大学 [2]日本国九州大学

出　　处：《大连理工大学学报》1993年第S2期185-193,共9页Journal of Dalian University of Technology

摘　　要：利用溶胶、凝胶法将白金族贵金属的超微粒子分散到多孔性氧化铝薄膜 的微孔表面，得到一种新型的多孔性气体分离膜．将这种薄膜应用到Ｈ２－Ｎ２ 混合气体的分离，在４００℃的高温下具有良好的气体选择透过性和分离能力． 研究结果表明，本薄膜的高温分离系数可达６．５～７．０，远高于根据Ｋｎｕｄｓｅｎ 扩散机理所推算出的３．７４的理论值和目前文献报道的同类型膜的２．５～３．０ 的水平．通过表面及显微分析，发现这种薄膜的透过机理是由化学吸附所引 发的表面扩散过程，从而加速了氢气的透过速度．另外，将这种膜用于膜反应 器中，应用到甲烷的水蒸气转化反应．由于反应过程所生产的Ｈ２通过膜源源 不断地分离出去，化学反应平衡向正反应方向倾斜，从而在较低温度下即可 获得很高的转化率．４７５℃，Ｓ．Ｖ．＝７５０～１０００ ｈ－１，Ｈ２Ｏ／ＣＨ４＝３．０的反应条 件下，甲烷的转化率达到８０％以上，几乎相当于固定床反应器及热力学平衡 值的２倍，同时可获得很高的Ｈ２收率．这种反应器在燃料电池、Ｈ２透平等新能 源体系的开发中具有广阔的应用前景．A microporous membrane for selective separation of hydrogen has been prepared using sol-gel method. Some metal salts such as RuCl3, Pd (NH3 )4C12, RhC13, and H2PtC16 have been added to the boehmite sol and coated on a porous alumina substrate before firing at 500℃. It is found that the permeability of hydrogen and the separation factor for hydrogen-nitrogen gaseous mixture of these metal dispersed membranes exceeded the value limited from the Knudsen diffusion mechanism. Although the gas permeation through neat alumina membrane was governed by the Knudsen diffusion ,the metals dispersed in alumina membranes were effective in promoting hydrogen permeation. The metal dispersed alumina membranes were also used to the membrane reactor for application to promotion of methane steam reforming at low temperature. In the temperature range of 300-500℃, the membrane reactor attained twice as large methane conversion as the equilibrium values of the single catalytic reactor system because of the selective removal of h ydrogen from the reaction system.

关 键 词：扩散 气体分离 膜材料 甲烷蒸汽转化法/金属分散多孔膜 氢选择渗透 溶胶-凝胶法 膜反应器 

分 类 号：N55[自然科学总论]