Synergic effect of methanol and water on pine liquefaction.

Pine liquefaction (PL) and re-liquefaction of its liquefaction residues in sub- and supercritical methanol, water or methanol/water mixed solvents (MWMSs) was investigated. The results show that isometric MWMS has the highest synergic effect on PL. Moreover, the total yield of bio-oil (BO) and conversion from pine and its residue both liquefied in the MWMS were obvious higher than those from PL in methanol (water) and re-liquefaction of its residue in water (methanol), suggesting that the interaction between the two solvents is responsible for synergic effect. This approach facilitates understanding the mechanism for biomass liquefaction in mixed solvents and developing efficient utilization process of biomass.