Comparison between WGS membrane reactors operating with and without sweep gas: Limiting conditions for co-current flow

In this work, a comparative study is carried out to analyze the behavior of a water gas shift membrane reactor operating with and without sweep gas. The present study includes thermal effects that play a key role in reaction and permeation rates involved in the membrane reactor. Based on a 1-D mathematical model, the effect of the most important operating variables on the membrane reactor performance is comparatively studied. Additionally, novel algebraic expressions are developed when operating without sweep gas, that only depend on inlet variables to calculate the limiting membrane reactor conversions and recovery values. An algebraic equation is developed to estimate limiting recovery when operating with sweep gas. The dependence of limiting membrane reactor conversion and recovery values operating with and without sweep gas on operating parameters is included. From the comparative analysis, some guidelines for an improved operation of the membrane reactor are proposed. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.