A model for the mass-transfer resistance at the surface of zeolite crystals

Abstract

A microdynamic model is proposed to describe the mass-transfer resistance localized at the surface of zeolite crystals. In addition to the intracrystalline diffusional resistance, this resistance occurs owing to the repulsion and attraction interaction between sorbing molecular species and the crystal surface. Especially for small crystals the surface resistance can exceed the intracrystalline diffusional resistance by several orders of magnitude. In particular, the model explains the non-linear behaviour of Arrhenius plots of uptake data exemplified for the sorption of n-hexane on NaMgA zeolite crystals.