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This research evaluates both the thermodynamic and experimental aspects ofdimethyl ether as a hydrogen carrier for fuel-cell feeds. The thermodynamics ofgenerating hydrogen from dimethyl ether via partial oxidation, by steam reforming, or bythe combined processes of partial oxidation and steam reforming were investigated asfunctions of temperature (100پ-C-6000C), steam-to-carbon ratio (0.00-4.00), oxygen-to-carbon ratio (0.00-2.80), pressure (1-5 atm) and product species. Thermodynamically,the resulting optimal processing conditions for dimethyl ether steam reforming occurredat a steam-to-carbon ratio of 1 SO, a pressure of 1 atm and a temperature of 200پ-C,resulting in a hydrogen production efficiency of 97 . These results also showed thatdimethyl ether hydrolysis to methanol, the first step in the steam reforming process toform hydrogen, was equilibrium limited.Modeling the start-up energies and efficiencies of an automotive scale on-boardfuel processor was also carried out as a function of fuel source (methane, methanol,ethanol, dimethyl ether and gasoline). Results demonstrated that a fuel processorutilizing dimethyl ether yielded the highest overall efficiency.Dimethyl ether hydrolysis to form methanol (the desired intermediate) wasstudied experimentally over a series of as-received catalysts of varying acidity (zeolites Yand ZSM-5, Zr02, y-A1203, Si02 and BASF K3-110) and also a series of in-houseprepared composite catalysts containing copper and zinc, using a packed-bed reactor.All the acid catalysts, with the exception of Zr02, attained the previously calculatedequilibrium-limited conversions to methanol in the temperature range of interest (1 25پ-C-400پ-C).Several homogeneous physical mixtures containing both an as-received acidcatalyst and BASF K3-110 (a methanol-to-hydrogen catalyst) were used to examine thetested for theQ1 PC1 bus cardBoth these projects mere sofixare des elopment efforts tonards contributing to dlfferentaspects of Roboucs and lZ1echatronics projects m the Controls and Roboucs Group..
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