The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of H2, CO, CO2 and H2O (steam) followed by water gas shift (WGS) and CO clean-up steps. The WGS reaction that shifts CO to CO2 and simultaneously produces another mole of H2 was carried out in a two-stage catalytic conversion process involving a high temperature shift (HTS) and a low temperature shift (LTS). In a typical operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about 3∼5%. The HTS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to a range of 2∼4%. The iron based catalysts (G-3C) was used for the HTS to convert the most of CO in the effluent from the partial oxidation (POX) to H2 and CO2 at a relatively high rate. Parametric screening studies were carried out for variations of the following variables: reaction temperature, steam flow rate, components ratio (H2/CO), and reforming gas flow rate.