Experimental study of Ni/MgO catalyst in carbon dioxide reforming of toluene, a model compound of tar from biomass gasification

An experimental study of Ni/MgO solid solution catalyst in CO2 reforming of toluene was conducted in this paper. Experimental parameters were reduction temperature, reaction temperature, CO2/toluene mole ratio, and toluene feed rate. An optimized reduction temperature was 700 degrees C to obtain the sufficient surface Ni as well as avoid the severe sintering of Ni particles. Either higher reaction temperatures or higher CO2/toluene mole ratios made Ni/MgO more stable and efficient. Ni/MgO at 550 degrees C and a high CO2/toluene mole ratio of 28 had a better activity with less coke than that at 570 degrees C but low CO2/toluene mole ratios (<= 14), which suggested the activation of carbon intermediates from the dissociation of toluene by abundant oxidizing CO2 species played a crucial role in having a better catalytic performance. At a high toluene feed rate (0.48 ml/h), Ni/MgO had an inferior activity due to the comparatively insufficient active Ni; moreover, it had a worse stability because of a large amount of coke. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.