DIFFUSION OF BENZENE IN NAX AND NATURAL FAUJASITE

Diffusion of benzene in large crystals of both natural faujasite and NaX zeolite has been measured by conventional gravimetric methods and by the new 'zero length column' chromatographic method. Results of both types of measurement are consistent, and the derived time constants show the expected square dependence on crystal radius, confirming intracrystalline diffusion control. As with the xylene isomers, there is no significant difference in diffusivity between natural faujasite and synthetic NaX. However, the corrected diffusivities are much smaller than the self-diffusivities derived from n. m. r. measurements.