The present study developed a low-CO methanol processor for the online supply of hydrogen to a proton exchange membrane fuel cell (PEMFC) composed of a steam reformer, a catalytic combustor and a reactor for the removal of CO. Commercial Cu/ZnO/Al2O3- and Pt/Al2O3-based catalysts were used in the methanol steam reforming and the preferential oxidation (PROX) reactor, respectively. The steam reformer was successfully heated with a catalytic combustor at room temperature without any additional electrical power supply. Hydrogen gas was obtained at a flow rate of 43.0 L h(-1) using a feed flow rate of 39.5 ml h(-1) (S/C=1.1) and an operation temperature of 250 degrees C, corresponding to a power output of 59 W-e. The CO concentration could be maintained at 4-5 ppm for stable operation. (C) 2011 Elsevier Ltd. All rights reserved.