Hydrogen production from the combination of catalytic partial oxidation of methane (CPOM) and water gas shift reaction (WGSR) viz the two stage reaction in a Swiss roll reactor is investigated numerically Particular emphasis is placed on the interaction among the reaction of CPOM, the cooling effect due to steam injection and the excess enthalpy recovery with heat recirculation A rhodium (Rh) catalyst bed sitting at the center of the reactor is used to trigger CPOM and two different WGSRs with the aids of a high temperature (Fe-Cr based) shift catalyst and a low temperature (Cu-Zn based) shift catalyst are excited Two important parameters including the oxygen/methane (O/C) ratio and the steam/methane (S/C) ratio affecting the efficiencies of methane conversion and hydrogen production are taken into account The predictions indicate that the O/C ratio of 1 2 provides the best production of H(2) from the two stage reaction For a fixed O/C ratio, the H(2) yield is relatively low at a lower S/C ratio stemming from the lower performance of WGSR even though the cooling effect of steam is lower On the contrary, the cooling effect becomes pronounced as the S/C ratio is high to a certain extent and the lessened CPOM leads to a lower H2 yield As a result with the condition of gas hourly space velocity (GHSV) of 10 000 h(-1) the optimal operation for hydrogen production in the Swiss roll reactor is suggested at O/C = 1 2 and S/C = 4-6 (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved