Microscale chemical devices have potential application as fuel processors to produce high purity hydrogen for PEM fuel cells from hydrocarbon fuels such as methane, methanol, ethanol, or gasoline. The fabrication of a novel stainless steel catalytic microcombustor/reactor suitable for use to high temperatures is described. The device consisted of three parts to accommodate catalyst loading: a laminated reactor body, a laminated combustor, and a solid cover plate. The laminated components were produced using stacks of photochemically machined stainless steel shims. When formed into solid leak-tight components using a diffusion bonding process, the laminated parts were designed to contain a complex series of internal gas-flow microchannels that could not be produced in a solid metal block by other fabrication methods. Included within the reactor body was an array of heat exchanger microchannels 250 microns wide and 5000 microns deep that were designed to extract heat from the catalytic reaction region and pre-heat the reactant gases. Catalytic combustion of hydrogen or hydrocarbon fuel occurred in a separate laminated combustor plate. The laminated combustor/reactor design has potential for use in a variety of chemical processing and heat exchanger applications.
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