Membrane reforming for hydrogen

Steam reforming of hydrocarbon feedstocks is by far the most dominating process technology for production of hydrogen. This process requires high temperatures to reach satisfactory conversions so alternative process routes are being sought. One such alternative is a process based on membrane reforming in which hydrogen is continuously removed from the reaction zone pushing the chemical equilibrium and enabling operation at moderate temperatures. This paper presents the results of an analysis of the membrane reforming process. The influence of various process parameters on the reactor performance is elucidated by detailed reactor calculations. It is shown that in general it is not possible to obtain satisfactory conversions of methane at temperatures below 600-650 degrees C. A comparison of the process economics with state-of-the-art hydrogen plants shows that membrane reforming only becomes attractive if the cost of electricity is very low and if the membranes are 100% selective to hydrogen. (C) 1998 Elsevier Science B.V. All rights reserved.