PNNL

Abstract

A microscale fuel reformer for use with a miniature fuel cell has been built and operated at efficiencies which make them attractive for use as a miniature power supply for microelectronics. The fuel processor assembly consists of two vaporizer/preheaters, a heat exchanger, a combustor, and a steam reformer. A microscale fuel reformer could process various hydrocarbon fuels. Methanol was identified as a good candidate for use in the microscale reformer. A Pd/ZnO catalyst was developed for use in the reformer. An integrated fuel processor using the Pd/ZnO catalyst in the reformer and catalytic combustion to provide the heat was designed and built. The reformer and combustor were each less than 5 mm3 in volume. A hydrogen rich stream composed of 73.5 vol.% H2, 25.8 vol.% CO2,and 0.7 vol.% CO on a dry basis. Almost 3 moles of hydrogen per mole of methanol reacted, which approached the theoretical maximum. When 100 mWe of hydrogen was produced, a thermal efficiency of 9.6% or 4.8% net efficiency was achieved. The device was able to operate without any external heating.