Hollow Fiber Loading Of The Preparation And Characterization Of Inorganic Membranes

Mesoporous silica membranes , microporous silica membranes and Al203,-Si02 composite membranes on hollow fiber alumina supports were prepared by a sol-gel process. The microstructure of the membranes was analyzed by sanning electro microscopy. Their permeability and gas separate ability were investigated by a gas separation installation. The thermal stability, composition, crystalline phase and pore size distribution of powder samples were studied by thermal gravimetric analysis, differential thermal analysis, FT-IR spectrograph, X-ray diffraction and isothermal nitrogen adsorption, respectively. The results showed that BET specific area of mesoporous silica membranes reached 919. 75m2/g and the total pore volume' was 0.4346ml/g. The most probable pore diameter was less than 3nm. Mesoporous silica membranes were free from large defects, the gas permeance of N2 and the separation factor of H2/N2 measured under room temperature and a pressure of 0.12MPa were 1.81Xl0-5mol/(m2 s Pa) and 2.431, respectively. For the microporous silica membranes, gas permeance reached the order of lO-6mol/(m2 s'Pa). Different mole ratios of Al203-Si02 composite membranes were free from crack and distinct flaws. The separation factor of hydrogen to nitrogen measured at a pressure of 0. IMPa was 3.03. It was showed that the gas diffusion through the membrane is governed by Knudsen diffusion mechanism. The most probable pore diameter of an unsupported membrane after calcination at 600℃ was less than 3 nm, its specific surface area reached 294.85m2/g and .the total pore volume was 0. 2778mL/g.