Computational fluid dynamics study of hydrogen generation by low temperature methane reforming in a membrane reactor Syed A.M. Said a,*,1 , David S.A. Simakov b,*,1 , Esmail M.A. Mokheimer a , Mohamed A. Habib a , Shakeel Ahmed c , Mohammed Waseeuddin a , Yuriy Rom  an-Leshkov b,* a Department of Mechanical Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia b Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA c Center for Refining and Petrochemicals, RI-King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia article info Article history: Received 29 November 2014 Received in revised form 5 January 2015 Accepted 8 January 2015 Available online 28 January 2015 Keywords: Hydrogen Methane reforming Membrane reactor CFD model abstract Concentrated solar energy can be used to drive highly endothermic reactions, such as methane reforming. An attractive route is the parabolic trough technology, which is mature and relatively inexpensive but limited to temperatures below 600  C, when methane conversions are low. However, high conversions are achievable if hydrogen is continuously removed from the reactive stream by a membrane selective to hydrogen. In this study, low temperature methane reforming in a membrane reactor is analyzed numerically by computational fluid dynamics over a wide range of operating parameters. Effects of temperature, steam-to-carbon ratio and space velocity on conversion, hydrogen recovery and carbon monoxide selectivity are specifically investigated. Our results show that concentration polarization can be significant. Below 500  C the reactor performance is kinetically limited by the reforming reaction, while above this temperature hydrogen separation is a limiting factor. High hydrogen recovery is achievable even at high, indus- trially relevant space velocities. Importantly, hydrogen separation enhances water gas shift, reducing the concentration of carbon monoxide, the main source of coke formation at low temperatures. Copyright © 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. * Corresponding authors. Tel.: þ966 13 8603123; fax: þ966 13 8602949. E-mail addresses: samsaid@kfupm.edu.sa (S.A.M. Said), dsimakov@mit.edu (D.S.A. Simakov), yroman@mit.edu (Y. Rom an-Leshkov). 1 These authors contributed equally. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 40 (2015) 3158 e3169 http://dx.doi.org/10.1016/j.ijhydene.2015.01.024 0360-3199/Copyright © 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.