PREPARATION OF MOLECULAR SIEVE INORGANIC THIN MEMBRANES FOR MEMBRANE REACTOR SYSTEM AT HIGH TEMPERATURE

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In organic membranes which had high permeability and excellent selectivity at high temperature were prepared in order to develop a membrane reactor system. Alumina membrane was packed with the ultrafine zirconia particles which was prepared by hydrolysis of zirconium tetrabutoxide in micro water pools of reverse micelles. From the gas permeation test with hydrogen and nitrogen, the permselectivity was higher than the theoretical value based on Knudsen mechanism. The palladium/silver alloy membrane was successfully deposited on a porous alumina support tube by spray-pyrolysis method. The permselectivity of hydrogen to nitrogen was about 24 at 500ﾟC.The palladium/alumina hybrid membrane was formed by a metal-organic chemical vapor depositon under reduced pressure. The hydrogen permeability and the permselectivity to nitrogen at 300-500ﾟC was higher than 10^<-8> mol m^<-2>s^<-1> Pa^<-1> and 1000 respectively. Barium titanate synthesized by hydrolysis of barium and titanium isopropoxides showed high absorption amounts of carbon dioxide at high temperature. The barium titanate sol was coated onto a porous alumina support by repeating dipping-drying-firing procedures. The permselectivity of carbon dioxide to nitrogen through the barium titanate membrane was about 1.2 at 100-500ﾟC.The permeation of carbon dioxide was enhanced by the surface diffusion on the pore wall.