- 3:15 PM

A Semi-Empirical Approach for Predicting the Performance of Mixed Matrix Membranes Containing Selective Flakes

Joshua A. Sheffel, Department of Chemical Engineering and Materials Science, Univeristy of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455-0132 and Michael Tsapatsis, Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave. SE, Minneapolis, MN 55455-0132.

In this presentation we will address a persistent problem in the prediction of mixed matrix membrane permeability and selectivity. On the one hand, analytical models which have been available for some time adopt a view of diffusion that is often too simplistic to accurately apply to zeolites. On the other hand, complex numerical approaches that apply more sophisticated treatments of diffusion to the complex mixed membrane geometry are often inaccessible to the experimentalist for the purpose of membrane design and performance evaluation. We will present an approach for predicting the performance of mixed matrix membranes containing zeolite flakes that combines well-known analytical expressions for mixed matrix membrane performance with Maxwell-Stefan modeling for zeolite diffusion. In so doing we hope to provide a realistic and practical tool for mixed matrix membrane design and performance evaluation. This approach will be illustrated through a case study of normal- and iso-butane separation by a membrane containing silicalite-1 flakes. Predictions will be compared to experimental results for a silicalite-1/PTMSP membrane found in the literature.