Valorization of crude bio-oil to sustainable energy vector for applications in cars powering and on-board reformers via catalytic hydrogenation

Crude pyrolysis bio-oil can be used as energy vector, but further upgrading is required before its utilization as transportation fuel and alternative hydrogen source. Therefore, the catalytic hydrogenation process of several model compounds (i.e. ether, alcohol, acid, olefin and guaiacol) and of crude bio-oil obtained by fast pyrolysis of nuts waste biomass has been investigated using CoMo/Al2O3 catalysts, pre-sulfided in flowing H2S at 400 °C, with different textural properties under simulated industrial conditions (T, 250e300 °C; P, 10e20 bar). Depending on the chemical structure of the various compounds, a complex reaction network, involving mostly hydro-deoxygenation (HDO), hydrogenation (HYD) and hydrocracking (HCR) processes, occurs. The simultaneous proceeding of all these reactions during the hydrotreating (HDT) of the crude bio-oil implies the formation of a wide range of hydrocarbon compounds documenting the feasibility of the upgrading process to obtain liquid transportation fuels and hydrogen-source compounds. A scale of reactivity based on the effectiveness of hydrogenation of compounds and functional groups has been proposed, also providing evidence of the effects of the texture and physico-chemical properties on the activity and selectivity of the CoMo sulfided catalysts in the HDT processes.