Mathematical Modeling of Gas Separation Process with Flat Carbon Membrane

Abstract

Carbon molecular sieve membranes (CMSMs) have been considered as very promising candidates for gas separation, in terms of separation properties as well as thermal and chemical stability. Due to the numerous advantages and wide applications of carbon membranes, their application for gas separation is of special importance. Because of the importance of carbon membranes and a large number of studies in the field of carbon membrane fabrication, in this study, mathematical modeling of the gas separation process in CMSMs has been investigated. Flat configuration is considered for the membrane, which has been applied for the separation process of CH₄ and C₂H₆. The Runge-Kutta method has been applied in order to solve the model. In the mentioned model, the sorption-diffusion mechanism has been considered as a dominant one for gas separation with CMSM. By comparing theoretical results with experimental ones for binary diffusion, good agreement was obtained. Finally, the effect of some parameters such as effective area of the module, module temperature, total feed pressure and feed flow rate on the purity of components in the retentate and permeate stream and recovery of fast components in the permeate stream have been investigated. Results demonstrated that increasing the effective area, membrane temperature and total feed pressure increased the recovery of the fast component in the permeate side, while the feed flow rate had an adverse effect.