A Study of Plate Type Catalytic Combustor for Hydrogen/CarbonDioxide Mixture Gas

A fuel cell system which uses hydrogen from fuel reforming, needs combustion heat of the residual gas from the fuel cell to support the endothermic reforming reaction and the evaporation of fuel. In the case of methanol reforming fuel cell, the residual gas contains hydrogen together with large concentration of carbon dioxide, which is more than 60 vol.%. New type combustor is needed for the combustion of the residual gas in wide mixture range, under low CO emission and low temperature for low damage of reforming catalysts. Thin plate type catalytic combustor using millimeter-scale protuberances is proposed and the combustion characteristics are examined comparing with conventional combustor. Proposed plate type catalytic combustor provided wide combustible range with residual gas of the reforming fuel cell, low CO emission lower than 50 ppm, low temperature combustion and low-pressure loss with combustor thickness smaller than 5.5 mm. The combustible range and combustion efficiency is effectively controlled by the height of protuberances and layout of fuel injection holes.