Microfuel processor for use in a miniature power supply

A microscale fuel reformer for use with a miniature fuel cell has been built and operated at efficiencies that make them attractive for use as a miniature power supply for microelectronics. The fuel reformer and the results of initial tests are discussed. The fuel processor assembly consists of two vaporizer/preheaters, a heat exchanger, a combustor, and a steam reformer. Methanol was identified as a good candidate for use in the microscale reformer. A proprietary catalyst was developed to reform methanol. The catalyst was able to process a methanol water mixture (1:1 by weight) into a hydrogen-rich stream composed of 73–74 vol% H2, 25–26 vol% CO2, and 0.6–1.2 vol% CO on a dry basis. Almost 3 mols of hydrogen per mol of methanol reacted, which approached the theoretical maximum. An integrated fuel processor that used proprietary 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. When 100 mWe of hydrogen was produced, a thermal efficiency of 9%, or an estimated 4.5% net efficiency (including a hypothetical fuel cell), was achieved.