Optimization of Organosolv Based Fractionation Process for Separation of High Purity Lignin from Bagasse

Abstract

Lignocellulosic biomass is a renewable source for sustainable production of fuels, chemicals, and other materials with the advantages on its carbon-neutral nature. Fractionation of lignocellulosic materials is a pre-requisite in the biorefinery process in order to convert the cellulose, hemicellulose, and lignin to valuable products with maximized economics prospective. In this work, a modified clean fractionation (CF) process using ternary mixture system of ethyl acetate/methanol/water was studied with the use of acid promoters. H2SO4 was found to be the efficient promoter due to low cost compare to other acid promoters. The optimal fractionation conditions operated in the solvent mixture containing 0.025 M H2SO4 at 160°C for 50 min led to 63.72% recovery of the cellulose in the solid pulp while 90% and 59.94% of hemicellulose-derived products and lignin were recovered in the aqueous-alcohol and organic fractions, respectively. The enzymatic digestibility of the cellulose-enriched pulp was increased, resulting increasing glucose yield from 38.32% of the native biomass to 70.04% using the hydrolysis reaction with Cellic Ctech2® at 15 FPU/g. The work demonstrated the applicability of the modified CF process for fractionation of lignocellulose components for integrated biorefinery process.