Isolation and characterization of acetosolv lignin present in sugarcane bagasse

Abstract

The lignin present in the vegetal tissues of the sugarcane bagasse is an interesting material due to its aromatic characteristics. Particularly in Brazil, studies involving the extraction of lignin from sugarcane bagasse have been widely researched due to the high volume of bagasse generated in our country. Recent studies have shown that after isolation, lignin is a raw material that can be used as a pesticide, solution stabilizer and particularly for the production of phenolic resin partially replacing phenol. The present study aimed to isolate and characterize the lignin present in sugarcane bagasse by the acetosolv pulping method. The sugarcane bagasse was pre-treated to remove organic and hot water-soluble extracts, and then acetic (solvent) and hydrochloric (catalyst) acids and water at the temperature were used. boiling point for the isolation of lignin by the acetossolve process. The obtained lignin was characterized by chemical performance analysis, Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and thermogravimetry (TGA). The extraction yield of lignin acetosolv was 19.95 % under total sugarcane bagasse. In the lignin FTIR spectrum the stretch range between 1594 and 1511 cm-1 confirm the preservation of the aromatic structure. GPC analysis demonstrated a low polydispersity of lignin acetosolv. TGA analysis showed no residues above 600°C, indicating high content of organic material, confirming the purity of the extracted sample. It is concluded, therefore, that the acetossolve pulping method for lignin extraction may be an efficient alternative, in view of the processes traditionally employed if fibers, not wood (sugarcane bagasse) are used. The fact that it is a process that does not use pressure combined with the possibility of recovering inputs by simple evaporation, makes the acetosolv competitive and with less environmental damage than other traditional processes.