Low temperature methane steam reforming for hydrogen production for fuel cells

Abstract

Low temperature methane steam reforming to produce H2 for fuel cells has been calculated thermodynamically considering both heat loss of the reformer and unreacted H2 in fuel cell stack. According to the thermodynamic equilibrium analysis, it is possible to operate methane steam reforming at low temperatures. A scheme for the low temperature methane steam reforming to produce H2 for fuel cells by burning both unconverted CH4 and H2 to supply the heat for steam methane reforming has been proposed. The calculated value of the heat balance temperature is strongly dependent upon the amount of unreacted H2 and heat loss of the reformer. If unreacted H2 increases, less methane is required because unreacted H2 can be burned to supply the heat. As a consequence, it is suitable to increase the reaction temperature for getting higher CH4 conversion and more H2 for fuel cell stack. If heat loss increases from the reformer, it is necessary to supply more heat for the endothermic methane steam reforming reaction from burning unconverted CH4, resulting in decreasing the reforming temperature. Experimentally, it has been confirmed that low temperature methane steam reforming is possible with stable activity.