Separating phenols from high-temperature fraction of bio-oil by precipitation

To improve the utilization of chemicals in bio-oil, recovery of phenolic compounds from high temperature bio-oil fractions by metal ion precipitation was studied.The effects of concentration of sodium hydroxide solution, reaction temperature and reaction time on the recovery of phenolic compounds by magnesium ion were examined using gas chromatography-mass spectrometry (GC-MS).The results demonstrate that the precipitation was formed instead of a salt of magnesium phenols.The optimum reaction conditions are reaction temperature of 25℃, 2.5 mol/L of sodium hydroxide solution, and reaction time of 20 min.In this case, the recovery of 4-ethylphenol from high temperature bio-oil fractions reaches 34.97%.