DESALINATION ELSEVIER Desalination 148 (2002) 275-280 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ www.elsevier.com/locate/desal Simulation of a new hybrid membrane/pressure swing adsorption process for gas separation I.A.A.C. Esteves, J.P.B. Mota* Departamento de Quimica, Centro de Q&mica Fina e Biotecnologia, Faculdade de Ck?ncias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal Tel. +351 (21) 2948300 (ext. 0961); Fax +351 (21) 2948385; e-mails: iaesteves@dq.fct.unl.pt, pmota@dq.fct.unl.pt Received 1 February 2002; accepted 25 March 2002 zyxwvutsrqponmlkjihgfedcbaZYXWVU Abstract A new hybrid gas separation process combining membrane permeation and pressure swing adsorption (PSA) is presented. An integrated model was formulated which successfully predicts all process characteristics. Our modeling work shows that the coupled process increases the efficiency of the pressurization and high-pressure adsorption steps, thereby improving the separation performance as compared to a standalone PSA. The new process has been applied successfully to the bulk separation of a mixture of 50/50 H,/CH, and preliminary results have been obtained for CO,,CH, and HJCO,/CH, mixtures. Keywords: Gas separation; Membrane permeation; Pressure swing adsorption; Hybrid process 1. Introduction are less severe [l]. Therefore, it is reasonable to Membrane permeation and PSA are frequently considered as alternatives to the conventional cryogenic gas separation processes. With the present generation of membrane processes, the PSA system still maintains an advantage in the high- purity region while membranes become clearly advantageous when product purity requirements *Corresponding author. expect that an optimized gas separation process integrating membrane and PSA improve product purity and/or recovery as compared to the stand- alone systems. Although coupled membrane-PSA processes have been proposed in the literature for various applications [2-6], most of them are essentially a simple combination of the two units and not a truly synergistically integrated process: either the Presented at the International Congress on Membranes and Membrane Processes (ICOM), Toulouse, France, Julv 7-12, 2002. 001 l-9 164/02/$- See front matter 0 2002 Elsevier Science B.V. All rights reserved PII:SOOl l-9164(02)00713-0