Biobutanol production from sugarcane bagasse hydrolysate generated with the assistance of gamma-valerolactone

Production of butanol from renewable resources is an attractive approach for introducing an economically competitive process. In the present study, sugarcane bagasse was hydrolyzed with the assistance of gamma-valerolactone (GVL). After phase separation, direct hydrolysis of sugarcane bagasse resulted in 24.08 g/L total sugars. Removal of lignin significantly increased the total sugar concentration to 248.41 g/L with a high yield of 0.87 g/g. Due to the low level of inhibitors in hydrolysate, the obtained hydrolysate was used as substrate for biobutanol production. Batch fermentation with 41 g/L sugars produced a high ABE concentration of 14.26 g/L, including 4.1 g/L acetone, 9.3 g/L butanol and 0.86 g/L ethanol. The fermentation with 61 g/L sugars greatly inhibited cell growth and solvent production due to the high concentration of NaCl and GVL. This study demonstrates that sugarcane bagasse hydrolyzed in GVL/water solution could be an alternative substrate for the low-cost production of biobutanol.