Influence of Acetone Co-Solvent on Furfural Production and Cellulose Retention from Lignocellulosic Biomass

This research aimed to obtain furfural from sugarcane bagasse with most cellulose residue preserved by using the system of diluted phosphoric acid and co-solvent acetone. Based on concentrated phosphoric acid and acetone pretreatment, 78.2% of the hemicelluloses in the bagasse were depolymerized into water soluble xylo-oligosaccharides, covering the cellulose residue. Then, in the pure acetone medium, no furfural was produced when pretreated bagasse was catalyzed by phosphoric acid at low reaction temperature (80 °C). The degradation of pretreated bagasse was strongly accelerated by increasing reaction temperature (120 °C), while no furfural was obtained due to its condensation with acetone. Adding water (12 mL) effectively slowed this process, with 10.6% furfural yield and 54.4% furfural selectivity, but acetone showed an inhibiting influence on furfural production compared to pure water system, under atmospheric conditions. Surprisingly, furfural production in the acetone-water medium was improved significantly when the reaction was pressurized, using xylose or bagasse as the feedstock. In pressurized conditions, higher furfural yield, shorter reaction time, and lower cellulose degradation were observed in the acetone-water medium versus the totally aqueous medium. This provided the potential of producing furfural and hydrolysable cellulose residue in the acetone co-solvent media.