Ni/Ce[sbnd]Al2O3 for optimum hydrogen production from biomass/tar model compounds: Role of support type and ceria modification on desorption kinetics

Abstract

This communication presents the synergistic role of ceria and alumina support type, in the gasification of glucose/toluene as biomass/tar model compounds over Ni/CeAl2O3. Two catalysts having 20 wt% nickel on a mesoporous Ce(x)-mesoAl2O3 (x = 0 or 1) were prepared via successive incipient wetness impregnation method. Two similar catalysts (i.e. Ni(20)/Ce(x)-γAl2O3, x = 0 or 1), were also prepared using a commercial γ-Al2O3 support. The catalysts show excellent activities for glucose/toluene mix feed as a biomass/tar model species. Physicochemical characterizations indicate that this method produces Ni/CeAl2O3 catalysts of moderate acidity, desirable pore size for biomass/tar conversion to syngas. Activity test in a riser simulator revealed that all the four catalysts are highly active for biomass/tar reforming at moderate temperature (i.e. 700 °C). In particular, Ni(20)/Ce-meso-Al2O3 was the best in terms of hydrogen production at low gasification temperature (i.e. 500 °C). This is due to its unique properties resulting from the synergistic effect of ceria promoter and our methodology for synthesizing Ce-doped-mesoAl2O3. For a 15 wt% mixed glucose/toluene feed at 700 °C and 30 s reaction time, the product composition over the Ni(20)/Ce-meso-Al2O3 catalyst was 74.33 mol% H2, 22.60 mol% COx and 3.06 mol% HC's (i.e. C1, C2, and C2=) with no tar in the product.