International Journal of Hydrogen Energy, Vol.44, No.30, 15811-15822, 2019
Ni/Ce-Al2O3 for optimum hydrogen production from biomass/tar model compounds: Role of support type and ceria modification on desorption kinetics
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/Ce Al2O3. Two catalysts having 20 wt% nickel on a mesoporous Ce(x)-mesoAl(2)O(3) (x = 0 or 1) were prepared via successive incipient wetness impregnation method. Two similar catalysts (i.e. Ni(20)/Ce(x)-gamma Al2O3, x = 0 or 1), were also prepared using a commercial gamma-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/Ce-Al2O3 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 degrees C). In particular, Ni(20)/Ce-meso-Al2O3 was the best in terms of hydrogen production at low gasification temperature (i.e. 500 degrees C). This is due to its unique properties resulting from the synergistic effect of ceria promoter and our methodology for synthesizing Ce-doped-mesoAl(2)O(3). For a 15 wt% mixed glucose/toluene feed at 700 degrees C and 30 s reaction time, the product composition over the Ni(20)/Ce-meso-Al2O3 catalyst was 74.33 mol% H-2, 22.60 mol% COx and 3.06 mol% HC's (i.e. C-1, C-2, and C-2) with no tar in the product. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Template-free Ce-Al2O3;Catalyst acidity;Desorption kinetics;Hydrogen production;Biomass/tar reforming