Recycled biorefinery system integrating phosphoric acid/acetone pretreatment of sugarcane bagasse with subsequent platform chemicals generation

In order to minimize the waste of polysaccharides (hemicellulose and cellulose) during preparation of platform chemicals (furfural and levulinic acid) from lignocellulose in one-pot acid/organic solvent systems, a novel two-step biorefinery system was developed based on sugarcane bagasse fractionation with a phosphoric acid/acetone pretreatment method. The effect of different pretreatment conditions on sugarcane bagasse fractionation was studied at first. Under the optimal condition (5 g bagasse, 40 mL 85% phosphoric acid, 50 °C, 1 h, precooled acetone), 72.5% xylose and 74.5% glucose (the residual biomass from pretreatment) were obtained. Acetone was evaporated and removed from the acetone extract, and then the soluble lignin was precipitated and recovered through the addition of water in the extract. The water solution (containing phosphoric acid and 20.8% xylose) and washing water from residue (containing 41.7%% xylose) was combined to produce furfural at 180 °C. Meanwhile, the potential of LA generation from cellulosic residue was evaluated via glucose conversion in different phosphoric acid/acetone systems.