A STUDY ON THE PREPARATION AND GAS PERMEATION OF POROUS ALUMINA SUPPORTS

The preparation and gas permeation of porous alumina supports were studied. The influences of the amount of PVA on the properties of the alumina slips, microstructure of the supports, and gas permeation were investigated. The experimental results show that the addition of PVA in the preparation process is useful for controlling the porosity of the supports without significantly changing other microstructural properties. Permeation measurements of H-2, He, CH4, N-2, O-2, and CO2 showed that gas transport through various supports under low transmembrane pressures (100-220 kPa) at room temperature (26.5 degrees C) was in the transition region, which combined the Knudsen diffusion and Poiseuille flow. The average radii of active pores for the supports, calculated from the gas permeability method, were compared with those measured by mercury porosimetry. The porosity-tortuosity factors and the tortuosity factors of the supports were also estimated and are discussed.