Development of a catalytic combustor for a stationary fuel cell power generation system

The anode off-gas of high temperature stationary fuel cell stacks still includes fuel components such as hydrogen, carbon monoxide, and hydrocarbon due to the innate characteristics of the fuel cell operation. Even though the anode off-gas has fuel contents, the flammability is very limited due to the vapor concentration of the anode off-gas. A catalytic combustor is applied as an off-gas combustor so as to utilize the waste energy of anode off-gas by stimulating a chemical reaction over selected operating conditions. Temperature and flow uniformity in the radial direction are very significant factors of the durability, because the catalytic combustion is carried out on the surface of the catalyst site. On the other hand, the catalyst selection is also very important due to the composition of the anode off-gas. In this study, the flow uniformity is presented prior to a catalyst screening test. From the results of the screening test, where three commercially available catalysts are tested, KIMM-I and KIMM-II are selected as candidates for a catalytic combustor of anode off-gas.