Effect of sorbate-sorbate interaction on micropore diffusion in steady-state adsorption processes

Abstract

Most studies dealing with micropore diffusion have assumed zero sorbate-sorbate interactions with good success. However, a recent study (van de Graaf, Kapteijn and Moulijn (1999). Modeling permeation of binary mixtures through zeolite membranes. A.I.Ch.E. Journal, 45(3), 497-511) has shown that the interactions can have a significant effect. In this paper, effects of sorbate-sorbate interaction in a steady-state microporous membrane process have been studied under a variety of operating conditions and system parameters. The generalized Maxwell-Stefan (GMS) models with and without sorbate-sorbate interaction have been analyzed to develop several useful analytical results. These models are then used to simulate numerically a tubular membrane process with a binary mixture. A detailed comparison of the two models shows that quantitative agreement between them results only under very restrictive conditions of either similar component diffusivities or operation in the linear range of isotherms. (C) 2000 Elsevier Science Ltd. All rights reserved.