Permeation of mixed gases in glassy polymer membranes

Abstract

AbstractSteady‐state permeation rates for pure CO2 and CH4 and the binary mixture through homogeneous dense polysulfone and polycarbonate membranes have been measured at 40°C and upstream pressures up to 26 atm. The pressure dependence of the mean permeability coefficients for CO2 and CH4 for all of the systems was simulated equally well in terms of the dual‐mode mobility models driven by gradients of chemical potential and concentration. The dual‐mode sorption and transport parameters used for evaluation of the mobility models are only those determined from sorption and permeation runs for a single gas. The approximate solution for the mean permeability coefficient of each component in a binary mixture was derived on the basis of the same mobility model driven by gradients of chemical potential. The deviation of approximate solutions from numerical ones remains less than 0.3%.