Diffusion of sorbates in zeolites by the frequency response method: particle shape and anisotropic effects

Abstract

The solutions of Fick's second diffusion law for a sinusoidal variation in the concentration of sorbate at the ingoing surface of spherical and infinite planar crystals have been used to obtain diffusion coefficients. In this paper the solution of the diffusion equation is extended to parallelepiped crystals and anisotropic diffusion is also considered. The results obtained are compared with those obtained assuming infinite plates and spherical crystals to ascertain the magnitude of the errors that could be introduced when an incorrect geometry is used.