Quantification of Non-Zeolitic Pathways in an Mfi Zeolite

An MFI zeolite membrane on an alumina support was subjected to several methods of permeation in an effort to characterize transport through the membrane. Specifically, the transport of molecules through the intercrystalline pathways of the membrane was considered. Many studies have been conducted on the permeation and separation of various components and mixtures through zeolite membranes. These studies, however, have thus far failed to yield a comprehensive picture of molecular transport through the grain boundaries between crystals in zeolite membranes. The main focus of this study is to see if the permeation methods of permporosimetry, pervaporation, and vapor permeation provide a complete illustration of how different molecules diffuse through both the zeolite pores and non-zeolitic pathways. The molecules of interest in this study are hexane and benzene which can both fit through the zeolite pores, and dimethylbutane (DMB), trimethylbenzene (TMB), and isooctane which are all too large to enter the zeolite pores.