In this presentation we will summarize the work performed at NETL on the production of hydrogen via partial oxidation/dry reforming of methane and catalytic decomposition of hydrogen sulfide. We have determined that high pressure resulted in greater carbon formation on the reforming catalysts, lower methane and CO2 conversions, as well as a H2/CO ratio. The results also showed that Rh/alumina catalyst is the most resistant toward carbon deposition both at lower and at higher pressures. We studied the catalytic partial oxidation of methane over Ni-MgO solid solutions supported on metal foams and the results showed that the foam-supported catalysts reach near-equilibrium conversions of methane and H2/CO selectivities. The rates of carbon deposition differ greatly among the catalysts, varying from 0.24 mg C/g cat h for the dipped foams to 7.0 mg C/g cat h for the powder-coated foams, suggesting that the exposed Cr on all of the foam samples may interact with the Ni-MgO catalyst to kinetically limit carbon formation. Effects of sulfur poisoning on reforming catalysts were studies and pulse sulfidation of catalyst appeared to be reversible for some of the catalysts but not for all. Under pulse sulfidation conditions, the 0.5%Rh/alumina and NiMg2Ox-1100oC (solid solution) catalysts were fully regenerated after reduction with hydrogen. Rh catalyst showed the best overall activity, less carbon deposition, both fresh and when it was exposed to pulses of H2S. Sulfidation under steady state conditions significantly reduced catalyst activity. Decomposition of hydrogen sulfide into hydrogen and sulfur was studied over several supported metal oxides and metal oxide catalysts at a temperature range of 650-850DGC. H2S conversions and effective activation energies were estimated using Arrhenius plots. The results of these studies will further our understanding of catalytic reactions and may help in developing better and robust catalysts for the production of hydrogen from fossil fuels.
PDF
download
878987797
028-85220240
