Characterization of lignin extracted from eucalyptus wood chip by organosolv and subsequent alkaline precipitation processes

The present work studied the characteristics of lignin extracted from eucalyptus wood chip by organosolv (as called organosolv lignin; OL), and organosolv subsequent alkaline precipitation (as called organosolv lignin subsequent alkaline precipitation; OLA). It is noted that lignin from soda process (as called soda lignin; SL) was also characterized for comparison. In detail, OL was fractionated using ternary mixture of methyl isobutyl ketone (MIBK): methanol: water in the presence with 0.008 M of H2SO4 acid promoters at 180?C for 60 min. Then, it was characterized by Klason lignin, elemental analysis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and Fourier transform-Infrared spectroscopy (FT-IR) to determinate the physico-chemical properties and structural features. When compared with OLA, the result of FT-IR proved the OL structure not changed when OL was treated with alkaline precipitation. Moreover; organosolv subsequent alkaline precipitation could remove the contaminations content of OL (i.e. sugar, sulfur, MIBK) due to their association between lignin and contaminations.