Micro-structured methane steam reformer with integrated catalytic combustor

Experimental results of tests using a micro-structured steam reformer for hydrogen generation from methane in fuel cell systems are reported. A distinctive feature of this work is the integration of a catalytic combustor into the reactor to deliver the necessary heat to the endothermic steam reforming reaction. The tests are performed under static and dynamic load conditions. The reactor is operated autonomously without external heat supply. The best results are obtained by firing the integrated combustor with a mixture of hydrogen and methane in co-flow with the reforming reaction. Providing carbon dioxide to the combustor feed in order to simulate the situation of anode off-gas firing has only minor effects on system performance. Under static load conditions up to 2 / min(-1) of hydrogen are produced at high methane conversion rates of about 70%. Start-up tests show that a stable product composition is obtained in less than 20 s after admission of methane to the reformer. Furthermore, the product composition shows only minor variations with throughput and load changes if heating adjustments are done simultaneously. Overall, the reactor proves to be very suitable for operation in fuel cell systems