The Autogenous Hydrogen Automobile
Richard D. Williams
Gregory A. Lorton
AbstractThe first phase of a feasibility study for the incorporation of catalytic steam reforming reactors into mobile power plant fuel systems has been completed. Two laboratory prototype reformers were used to steam reform hexane feedstock to fuel gas mixtures consisting of H2, CH4, CO, and CO2. Above 485°C conversion was found to be equilibrium (rather than kinetically) controlled by the methane reforming and water gas shift reactions. Reactors used were 1) a 9" long section of 2" stainless steel pipe, and 2) a 5" long section of 3-1/4" stainless steel pipe. In both cases the reactors were filled with Girdler 5/8" raschig ring nickel reforming catalyst. Reactor residence times near .01 seconds allowed complete conversion of hexane to theoretically predicted equilibrium product distributions. Experimental hydrogen composition in the fuel gas generated at 2.5 atm with a steam to carbon ratio of 2.56 ranged from .38 to .68 mole per cent (dry basis) at temperatures of 485°C and 695°C respectively. The equivalent reactor volume required to provide fuel gas at a rate sufficient to power a medium sized car at 60 mph is estimated to be on the order of 0.2 cubic feet. Additional size reduction may be realized with more active reforming catalysts especially considering that operation was not found to be kinetically controlled.
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