High efficiency reforming is a key parameter of high temperature stationary fuel cell system. In this study, a planar heat exchanger steam reformer (PHESR) was integrated with catalytic combustor in order that the unused energy of anode off-gas is delivered for heat of reforming. The PHESR was designed to use the anode-off gas of externally reformed SOFC system because it has an efficiency problem. In the PHESR reactor, the heat is transferred from catalytic burner to reformer that has weak gradient of temperature difference between two reactors.
The thermal behaviors of exothermic and endothermic reactions between reactors were investigated experimentally. The parameters of investigation were fuel utilization, inlet temperature, and air excess ratio. Comparison parameter was volume fraction of hydrogen at the exit of reforming side. The temperature gradients in longitudinal direction of two reactors were measured. As expected, temperature differences between two reactors were crucial factors that required optimization. Furthermore, the geometric aspects between the finned and un-finned reactors were also investigated. The results demonstrate that the volume fraction of hydrogen at the exit is closely coupled with the geometric constraints and the operating parameters.