PERMEATION OF GASES THROUGH A SUPPORTED ALUMINA MEMBRANE

The permeations of He, N2, and CO2 through the supported alumina membr ane were studied in this work. The permeabilities of gases were measur ed under temperature ranges of 299.4-372.7 K and pressure up to 220 kP a. Experimental results showed that the gas transported through the al umina membrane can be described by the combination of Knudsen diffusio n, Poiseuille flow, and surface diffusion. However, Knudsen diffusion played the most important role on the permeabilities of gases. A semi- empirical expression of permeability was obtained as a function of tem perature and pressure for each pure gas. The permeate fluxes of He-N2, He-CO2, and N2-CO2 mixtures were calculated from permeabilities of pu re gases with assumptions of perfect gas behavior and complete mixing permeator. The predicted data were coincidence with the experimental r esults except for N2-CO2 mixture. The deviation of permeability betwee n the predicted and the experimental data for N2-CO2 system can be red uced by taking into account of viscosity effect.