Permeation of linear and branched alkanes in ZSM-5 supported membranes

Diffusion of methane, n-butane, n-hexane, isobutane and 3-rmethylpentane in ZSM-5 supported membranes was studied in a wide range of temperatures from ambient to 723 K. The Maxwell-Stefan equations were used for the interpret ation of the results. From these, micropore diffusion coefficients and appa rent diffusion activation energies were obtained. For the light linear and branched alkanes (C-1 and C-4), the literature data obtained with macroscop ic or microscopic techniques or molecular dynamics (MD) simulations are in rather close agreement. In contrast, for n-hexane, the literature data show strong discrepancies. Our diffusivities agree only with the reported macro scopic data. Considering 3-methylpentane molecules, our diffusivities are i n close agreement with the macroscopic literature data, but the comparison with the microscopic results is limited. (C) 2000 Elsevier Science B.V. All rights reserved.