Modeling, simulation and optimization of membrane-based gas separation systems

This paper presents various aspects of modeling, simulation, design, and op timization of membrane-based gas separation systems. A model for counter- a nd crosscurrent membrane modules and an efficient numerical solution proced ure based on orthogonal collocation to solve the differential model equatio ns have been developed. The model handles multicomponent mixtures and consi ders effects of pressure drop and energy balance. The model and solution pr ocedure are combined in a versatile unit which can be conveniently used in a process simulator. The solution procedure allows analytical calculation o f sensitivities. The membrane module has been implemented and tested in an external process simulator, OPTISIM, which is based on the equation-oriente d approach. The cost optimization features of OPTISIM have then been used t o investigate hybrid schemes for CO pretreatment of steam reformer gas:The traditional cold box has been modified with a membrane unit and the results of the cost optimization calculations are presented. (C) 1999 Elsevier Sci ence Ltd. All rights reserved.