(536c) Solvent Mediated Extraction of Fast Pyrolysis Bio-Oils for Isolating Phenolics

Fast pyrolysis of agricultural residues produces a viscous liquid (bio-oil) that can serve as a precursor to renewable drop-in fuels and coproducts. While adaptation of bio-oils to a refinery serves as the ideal, the feasibility relies heavily on the oxygen content of said bio-oil. A relatively low oxygen content (< 16 wt% O) would lower both oil density and reactivity. Distillation of these bio-oils proceeds with significant yields of organic compounds. However, if oils cannot undergo distillation due to reactive instabilities, then separation methods are still desirable for further upgrading. A modified extraction method on whole oil could bypass distillation of unstable oils, which could also reduce heat duty and process costs if extraction is performed first.

In the past we’ve shown that one-ring phenolics can be extracted from distillates of partially deoxygenated bio-oils (<16 wt% O), thereby producing a hydrocarbon fraction in parallel. We will discuss the use of solvent-mediated extraction of whole bio-oils, (16 - 24 wt% O) based on toluene and isopropyl alcohol. Bio-oils of varying oxygen content and quality underwent extraction with toluene. The toluene soluble fraction (TS) underwent extraction with 10M NaOH, thus producing phenolics and hydrocarbon fractions. The Toluene insoluble fraction (TI) underwent extraction with isopropyl alcohol, producing soluble and insoluble fractions (IPA-S; IPA-I). We successfully isolated hydrocarbon fractions and one-ring phenolics without distillation, with the option to further upgrade the highly oxygenated IPA-S and IPA-I fractions. Specifically, the IPA-I fraction underwent py-GCMS with and without catalyst, which showed conversion to deoxygenated gasoline and jet fuel-range compounds.