Transmembrane gas transfer through a two-layer membrane

Abstract

Gas diffusion through a two layer membrane is studied within the lattice model of an ideal gas. Analytical expressions are derived for transmembrane diffusion gas flux and permeability of the membrane. It is revealed that the value of the transmembrane gas flux may depend on the membrane orientation. An expression is obtained for the asymmetry coefficient of diffusion gas transfer. It is shown that the revealed effect of asymmetry of membrane diffusion permeability arises in the case of nonlinear sorption isotherms. The results obtained can be used to predict the separating characteristics of composite membranes. Layer 1 Layer 2 0 l 2 l J D1 p in Layer 1 Layer 2 J D1 J D2 D D J J J = = 2 ≠ 12 21 , J J ≠ 12 21 P P ≠