On the separation factor of binary gaseous mixtures in two-layer nanoporous membranes

The separation factor is calculated for a binary gaseous mixture in two-layer membranes composed of nano- and microporous layers. The transfer in nanosized pores is described with regard to the diffusion in an adsorption layer. The mutual influence of components when they pass through the fine-pore layer is taken into account. The dependence of the diffusion coefficients in the adsorption layer on the degree of surface coverage is taken into account. It is shown that the mutual influence of the components on the transfer in the adsorption layer substantially affects the separation factor and its dependence on process parameters. The problem concerning the asymmetry of the separation factor at different membrane orientations with respect to the flow is discussed.