Improved catalytic upgrading of simulated bio-oil via mild hydrogenation over bimetallic catalysts

The bio-oil, produced via fast pyrolysis of biomass, can be used as substitute for transportation fuels after its subsequent upgrading. However, conventional upgrading of bio-oil faces serious problems of rapid catalyst deactivation and low conversion efficiency, due to the high unsaturation degree of bio-oil. In this study, the mild hydrogenation of simulated bio-oil over monometallic catalysts (Pd and Pt) and bimetallic catalysts (Pt-Fe, Pd-Fe, Pt-Ni and Pd-Ni) was performed, in order to increase the saturation degree. It was found that the addition of Ni could significantly facilitate the conversion of phenols. The maximum conversion of guaiacol and phenol over Pt-Ni/SiO2 catalyst reached 97.8% and 99.6%, respectively. The introduction of Fe improved the conversion of AcOH by promoting the protonation of carbonyl group. Complete conversion of AcOH was achieved over Pt-Fe/SiO2 catalyst. The upgraded product, of which the activity was significantly improved, was ready for subsequent upgrading for liquid fuel production.