The aim of this research was to evaluate the potential for the stabilization of biomass-derived pyrolysis oils by using acid-catalyzed (Amberlyst 70) reactions with alcohol (T=140–170 °C, P≈20 bar (1 bar=105 Pa)). The alcohol-stabilized oils were further upgraded by catalytic hydrotreatment (T=400 °C, non-sulfided NiMo/Al2O3 catalyst) to give a biofuel. The concept was evaluated experimentally in terms of overall mass and energy balances and biofuel properties. The pyrolysis oil used in this study was obtained by fractional condensation of pyrolysis vapors and had a very low water content that favored the equilibrium conversion of the stabilization reactions. The energy efficiency was between 44 and 48 %. Preliminary results with acid-leached biomass showed that 43 % of levoglucosan in the pyrolysis oil was converted into methyl levulinate after the pyrolysis oil was purified. The proposed integrated concept of alcoholysis can be applied locally at the pyrolysis oil production site.
- analytical methods
- process chemistry