Hydrogen production by ethanol steam reforming. A reaction mechanism

J. COMAS, V. MAS, G. BARONETTI, M. LABORDE, N. AMADEO

La Habana

Congreso; Hypothesis VI; 2005

Academia NAcional de Ciencias de Cuba

The aim of this work is to identify the active species on Ni(II)-Al(III) catalysts prepared from lamellar double hydroxides as precursor in the ethanol steam reforming reaction. A comprehensive analysis of the kinetics results obtained at different water/ethanol feed ratio in ethanol and methane steam reforming (ESR and MSR respectively), and its correlation with the structural characteristic and redox behavior of the catalyst is carried out. The results show evidences that the catalyst behavior is related with the presence of an only one type of active site in the Ni/Al2O3 catalyst. The competition for the active sites between reactants is verified for MSR. This behavior can be also observed in ESR since methane steam reforming determines the concentration of products in the exit stream. The results suggest that there would be an optimum inlet water concentration that gives a maximum performance in terms of hydrogen and CO2> selectivity and, simultaneously, a minimum CO selectivity. Taking into account that the hydrogen flow entering to a PEM fuel-cell requires a CO concentration lower than 20 ppm, this is a promissory result in order to minimize CO production.