Mixed Matrix Membrane Performance Prediction for Gas Separation using Modified Models

Abstract

Gas separation using membrane processes are potentially economical in industrial scale. Two parameters are used for analyzing the membrane separation performance: permeability and selectivity. There is a trade off between them for polymeric membranes that makes it impossible to increase both of them simultaneously. Molecular sieve membranes, on the other hand, exhibit high permeability and selectivity but are brittle in nature and costly. A new generation of membranes has made many hopes to use simultaneously both desired properties of polymers and molecular sieves in a structure called “mixed matrix membrane (MMM)†where a molecular sieve is incorporated within a polymer matrix. As other branches of science and engineering, having a tool to predict MMMs performance seems to be essential to save time and money for research and industrial applications. Many mathematical models were developed to predict MMMs performance based on separation performance of fillers and polymers. Maxwell model is the simplest model developed for prediction of electrical properties of composite materials but it is not perfect for all cases. Some modifications were performed on Maxwell model and some other modified models were developed for better prediction of MMMs separation performance. In this research, modified Maxwell and Bruggeman models were employed to predict gas separation performance of some MMMs in the current work and the results were acceptable for all non–ideal cases which might be occurred in MMMs structure.