Alumina Supported Ni-Mg-La Tri-Metallic Catalysts for Toluene Steam Reforming as a Biomass Gasification Tar Model Compound

Abstract

The steam reforming of toluene as a model compound of biomass gasification tar was carried out over Mg and La oxide-promoted Ni-metal oxide/Al2O3 catalysts. Catalysts were prepared by two different methods, co- and sequential impregnation. The findings indicate that conversion of gas products was improved with the use of prepared catalysts especially on syn-gas (H2 and CO) species and the highest conversions were obtained at the reaction temperature of 800°C. LHV’s of product gas when using catalysts at 800°C were over 4 MJ/m3 and ratios of H2 to CO were between 2.49-2.77. For long term test, Carbon and hydrogen conversion to CO and H2 of the catalysts with respect to time on stream in the steam toluene reforming for 480 min were studied. La2O3+MgO+Ni/Al2O3 catalyst revealed the highest and stable conversion rate of closely 50% and 70% for CO and H2, respectively. Whisker carbon species and encapsulating carbon were found on used catalysts after reaction. The La2O3+MgO+Ni/Al2O3 catalyst showed lesser amount of whisker carbon and encapsulating carbon.