Bioethanol Steam Reforming on Suported Nickel Catalysts

Biofuels such as ethanol, biodiesel and biohydrogen are the main alternative fuels of the future. Currently nearly 95% of hydrogen is produced by reforming hydrocarbons (natural gas), reason for what hydrogen production technologies by catalytic processing oxygenate compounds prepared from renewable resources become attractive. One way of manufacturing hydrogen consists of catalytic reforming of biomass. Catalytic reforming of bioethanol has been studied on suported nickel catalysts. Ni / SiO2 – y Al2O3, Ni / y Al2O3 diatomite and Ni / diatomite – y Al2O3 – H ZSM5 catalysts were prepared by the method of incipient wetness using nickel nitrate as a metal precursor. Textural characteristics of the catalysts were determined on a device Autosorb1 Quantacrome and acid strength distribution was determined by thermodesorption of diethyl-amine in the temperature range 20 – 700°C. Evaluation of catalysts surface conformation and distribution of clusters of active component on the inner surface of the catalysts was done by SEM microscopy and hydrogen consumption of catalysts studied depending on temperature was assessed over a range between ambient temperature and 850 °C, to optimize phase activation of catalyst. Reforming of ethanol has been made in a laboratory reforming plant coupled with a gas chromatograph Varian CP-3800. The main reaction products were hydrogen, carbon dioxide and methane. Ethanol conversion was higher for the three catalysts tested and hydrogen yield have higher values for the Ni / diatomitey Al2O3 H-ZSM5 catalyst.