Catalytic hydrotreatment of macroalgal bio-oil using supported palladium and copper chromite catalysts was systematically studied. The aqueous fraction of brown algal bio-oil (BABO) produced by fast pyrolysis was used as feedstock and was hydrotreated in temperature range of 250-400 °C at LHSV 0.48 h-1 and 10 MPa H2 using a trickle bed reactor. The yields of the organic phase products over the 5wt% Pd/Al2O3 and CuCr2O4 catalysts were maximal 42.33 wt% and 39.73 wt% at 350 °C, respectively. When the reaction temperature increased, the H/C ratio of the organic products increased with decreasing the O/C ratio. The carbon double bonds along with proof of unsaturated compounds were saturated by catalytic hydrotreatment. The supported palladium catalysts produced more furans and esters with increasing carboxylic acids in aqueous phases, whereas the copper chromite increased the heterocyclics and phenolics.
Keywords Macroalgae, Brown algae, Bio-oil, Catalytic upgrading, Hydrotreatment