Determination of the intracrystalline diffusion coefficients of alkanes in H-ZSM-5 zeolite by a transient technique using the temporal-analysis-of-products (TAP) reactor

A transient technique using the temporal analysis of products (TAP) reactor system was used to determine the intracrystalline diffusion coefficients of isobutane and 2-methylpentane in a H-ZSM-5 zeolite sample at temperatures between 423 and 598 K. A mathematical model was set up which describes the transport phenomena occurring in the transient experiment. The features of this model were then explored by model simulation. The method and the underlying model were successfully validated by fitting experimental data, deriving intracrystalline diffusion coefficients by parameter estimation, and comparing them with published values obtained by independent methods. (C) 1998 Elsevier Science Ltd. All rights reserved.