The use of the method of densitometry of light passing through a layer of zeolite crystals permits determining the limiting stage of diffusion during adsorption by zeolites. Diffusion in transport pores and external heat exchange play the basic role in adsorption of benzene by NaX zeolite, while diffusion in crystals was the determining mechanism of transport in adsorption of water by NaA and NaX zeolites. The diffusion coefficients of water in NaX zeolite had an order of magnitude of 10-17m2/s and increased with an increase in the degree of filling. An explanation for the anomalous behavior of the kinetic adsorption curve for brief times of adsorption of water by zeolite was proposed.

Study of Intracrystalline Diffusion and Conduction in Zeolites 6. Comparison of the Results Obtained by the Method of Densitometry of Light and the Adsorption Method. A.M.Voloshchuk, V.A.Gorlov, T.A.Moskovskaya, L.S.Reifman, V.N.Chechevichkin, A.A.Yurkevich: Bulletin of the Academy of Sciences of the USSR - Division of Chemical Science, 1990, 39[6], 1097-100