The Maxwell-Stefan formulation of diffusion in multi-component mixtures was used to obtain explicit formulae for calculating the diffusivities of binary mixtures within a zeolite matrix. The theoretical development permitted the estimation of the mixture-diffusivities on the basis of pure-component diffusivities at zero loading. The applicability of the Maxwell-Stefan model was demonstrated by comparison with published molecular dynamics simulations for mixtures of methane-perfluoromethane, methane-xenon and methane-n-butane in silicalite.

Diffusion of Binary Mixtures in Zeolites: Molecular Dynamics Simulations versus Maxwell-Stefan Theory. R.Krishna: Chemical Physics Letters, 2000, 326[5-6], 477-84. See also: Langmuir, 2001, 17[1], 247-54