Effect of extraction temperature on depolymerization characteristics of ethanol organosolv lignin in supercritical ethanol

Effect of extraction temperature (160, 180 and 200 ℃) on depolymerization characteristics of ethanol organosolv lignin (EOL) was investigated with a micro autoclave reactor. Three different EOLs (EOL-160, EOL-180 and EOL-200) were prepared by controlling extraction temperature, and their properties including functional groups, molecular weight distribution and thermogravimetric properties were analyzed by infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and thermogravimetric analysis (TG). The liquid and solid products obtaining from EOLs depolymerized in supercritical ethanol were analyzed by gas chromatography/mass spectrometry (GC/MS) and FT-IR, respectively. The results show that the main phenolic compound product for EOL-160, EOL-180 and EOL-200 depolymerized in supercritical ethanol were paraethyl phenol, 2,6-dimethoxy phenol and 4-hydroxy-3-methoxy-benzoate, respectively.