A reactor integrating catalytic combustion

heat exchange and steam reforming was developed for a 1 kW solid oxide fuel cell-combined heating and power system (SOFC-CHP). Experiments were carried out to investigate the effect of combustion gas components and process parameters on properties of the reactor. The results showed that methane conversion rate was 73.6% and hydrogen concentration in the exhaust gas was 67.5% under operating conditions at the inlet temperature of combustion gas of 300℃

air-fuel ratio of 10:1

fuel utilization of stacks of 65% and water-carbon ratio of 3:1. Fuel utilization of the SOFC stacks had significant effect on methane conversion. Waste heat recovery from the exhaust gas combustion cannot provide enough heat for methane steam reforming when the fuel utilization was greater than 80%. Reduction of the inlet temperature of combustion gas had slight effect on methane conversion in the range of 150-350℃. Thus

it was recommended that the heat exchange can be firstly conducted before catalytic combustion to improve heat efficiency without obvious change to reforming reaction efficiency. Reduction of air-fuel ratio under the premise of ensuring the efficiency of reforming can decrease power consumption of the compressor and increase the system efficiency. This achievements can provide guidance to the increase of the whole system efficiency and optimum design of SOFC-CHP.