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

- Sugarcane bagasse was hydrolyzed with the assistance of gamma-valerolactone.
- Removal of lignin significantly increased the sugar concentration.
- Low concentration of inhibitors was generated during the hydrolysis.
- The obtained hydrolysate was successfully used for butanol production.

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.

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