H-2/CO2 separation characteristics of gamma-Al2O3 membrane by aging stage in sol-gel process

gamma-AlO(OK) sol solution was prepared by aluminum isopropoxide as an init ial material. gamma-Al2O3 membrane on the alpha-Al2O3 support was continuou sly made through coating and thermal treatment from the gamma-AlO(OH) sol. Previous work [Yoo et at., 1997] has shown that the aging stage in the sol preparation process mainly affects the characterization of gamma-Al2O3 part icles as well as gamma-AlO(OH) sol. Based on this fact, the gamma-Al2O3 mem brane was prepared with two aging conditions in the present study. The sepa ration characteristics experiment of the H-2/CO2 mixture was performed on t hese membranes. As a result of the study, the mechanism of gas transport on the two membranes was proved as Knudsen diffusion. The ideal separation fa ctor was reached at the value of the calculated Knudsen separation factor; however, permeability increased and selectivity decreased selectivity accor ding to the aging.