Tandem Hydrodeoxygenation Catalyst System for Hydrocarbons Production from Simulated Bio-oil: Effect of C–C Coupling Catalysts

Research in the sustainable conversion of biomass to fuels and chemicals is a necessity for the reduction of the carbon footprint in transport energy. Herein, we demonstrate an efficient tandem catalyst to selectively convert (simulated) bio-oil to hydrocarbons with enhanced C4+ fuel yield in a fixed bed reactor of a small pilot plant. The tandem catalytic system is a multifunctional dual bed system; carbon coupling catalysts (0.2 wt % X-TiO2(X: Ru, Pd, Au) at the upper layer and hydro-deoxygenation (Ru-MoFeP/Al2O3) at the bottom layer in a single fixed bed reactor. The upper-bed catalysts facilitated the carbon coupling reaction of C2–C4 light oxygenates and significantly reduced the light gases yield (C1–C5) to ca. 40% and increased the organic (C4+) phase ca. 15%. The analysis of the organic phase suggests that among the screened upstream catalysts, 0.2 wt % Ru/TiO2||Ru-MoFeP/Al2O3 recorded the optimum activity. The coupled light oxygenates (acetone) alkylated with the phenolic compounds and sequentially hydro-deoxygenated to yield higher C4+ hydrocarbons. This versatile tandem catalytic approach has a potential application in the emerging biorefinery concept.