Development of Porous Catalyst Layer Microcombustor and Micro-Cogeneration System

Abstract

Development of a microcombustor with platinum porous catalyst layer and a cogeneration system using thermoelectric (TE) modules is introduced. In order to overcome the huge heat loss due to the small size of combustion field, catalyst combustion has been adopted because it has great advantage under the condition where the surface/volume ratio becomes large. To develop the monolithic porous structure of platinum, platinum powder is sintered in fuel-air mixture; the heat from the surface reaction melts the particles and makes agglomerates. The combustor is 5W class, but the heat release density of the combustor is 5GW/m³, which is comparable to that of conventional turbulent combustor. We couple the combustor with TE modules to convert the thermal energy to electricity. The TE modules are also preferable for small size generators because their characteristics that they use the heat flux from the hot zone to the surroundings match microcombustion. The output of the developed cogenerator is 165mW for thermal input of 4.7W; the final conversion ratio from fuel enthalpy to electricity reaches 3.5%. After integrating the micro-blower to supply air to the combustor, the cogeneration system shows the final efficiency of 1.7%.