Separation of phenols from lignin pyrolysis oil using ionic liquid

The aim of this work was to propose an efficient process to extract phenolic compounds from bio-oils produced by lignin pyrolysis. The extraction of phenolic compounds from the crude bio-oils was performed in two steps. First, a 5-stages liquid-liquid extraction (LLE) was performed with a basic aqueous solution. The second step consisted of a 4-stages LLE carried out with either ethyl acetate or [Choline][NTf2] ionic liquid as a green alternative solvent. It was found that the extraction of the phenolic compounds with the basic aqueous solution in the first LLE needs improvement. The extraction rates show that [Choline][NTf2] is an excellent solvent for the recovery of phenolic compounds from aqueous solution as compared to the classical ethyl acetate organic solvent.