PREPARATION AND CHARACTERIZATION OF SILICON BASED INORGANIC MEMBRANE FOR GAS SEPARATION

This paper presents a method for preparing a silicon based inorganic membrane. The inorganic membrane prepared by the polymerization-pyrolysis process exhibits high permeability, selectivity, and heat resistivity. Furthermore, the preparation process is simple, inexpensive and highly reproducible. By varying the polymerization and/or pyrolysis conditions, inorganic membranes with different physical properties can be obtained. In this paper, a modified diffusion equation for gas permeation through microporous media in the Knudsen regime was derived theoretically as a function of both temperature and pressure. A refined expression was obtained for the adsorbate flow (activated diffusion) by evaluating the partition functions and using the appropriate adsorption isotherm. Permeabilities of H-2, O2, N2, Ar, CH4, CO and CO2 through a silicon base inorganic membrane were measured in the temperature range of 25 to 200-degrees-C and pressure range of 10 to 50 psig. Experimental data were correlated based on the newly derived activated diffusion equation. The agreement between the experiments and theory was good.