Chemical Engineering Science, Vol.66, No.23, 6287-6296, 2011
Steam reforming of kerosene over a metal-monolithic alumina-supported Ru catalyst: Effect of preparation conditions and electrical-heating test
A plate-type anodic alumina support (gamma-Al2O3/Fe-Cr-Ni alloy/gamma-Al2O3) was used to prepare a series of Ru catalysts. The performance of these catalysts was investigated in the steam reforming of kerosene (SRK). Ethanol solution impregnation was used to enhance metal dispersion on the catalyst surface. The catalyst prepared by ethanol solution impregnation and dried at 120 degrees C (Ru/Al2O3-ED) gave a higher metal dispersion and more favorable activity and durability than that prepared in aqueous solution. However, owing to shrinking caused by the oxidation of ruthenium species, high temperature calcination in air after impregnation greatly decreased the metal dispersion on the catalyst surface, regardless of the impregnation solution type. In contrast to calcination in air, high temperature N-2 treatment could decompose the reducible ruthenium species on the Ru/Al2O3-ED completely. This indicates that H-2 pre-reduction is not an essential procedure for the SRK reactions over this catalyst. The experimental results also confirm this hypothesis. The effect of Ce addition was also investigated and was found to enhance significantly the catalyst tolerance to carbon deposition thereby improving the SRK durability of Ru/Al2O3-ED under a high space velocity. In addition, owing to the high electrical resistance of the Fe-Cr-Ni alloy, the anodic alumina catalyst itself can be used as a heater, when an electrical current is applied along the alloy layer. Under an electrical-heating pattern, the SRK reaction system reached stability within 15 min, offering a strong possibility for shortening the start-up time of conventional reformers from 1 to 2 h to a few minutes. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Catalysis;Catalyst deactivation;Catalyst support;Chemical reactors;Anodic alumina support;Kerosene steam reforming