Enhancing enzymolysis and fermentation efficiency of sugarcane bagasse by synergistic pretreatment of Fenton reaction and sodium hydroxide extraction

• Fenton reaction combined with NaOH extraction was employed to pretreat SCB.
• The process parameters of Fenton reaction were optimized.
• The pretreatment performance was related to the combinational sequence.
• The combinational pretreatment had an excellent SSF performance.

A study on the synergistic pretreatment of sugarcane bagasse (SCB) using Fenton reaction and NaOH extraction was conducted. The optimized process conditions for Fenton pretreatment were 10% (w/w) of H2O2, 20 mM of Fe2+, pH 2.5, pretreatment time 6 h, and pretreatment temperature 55 °C. Sequential pretreatments were performed in combination with NaOH extraction (NaOH 1% (w/w), 80 °C, 5% of solid loading, 1 h). Among all the pretreatments, Fenton pretreatment followed by NaOH extraction had the highest efficiency of 64.7% and 108.3% for enzymolysis and simultaneous saccharification fermentation (SSF) with an ethanol concentration of 17.44 g/L. The analyses by the scanning electron microscopy, X-ray diffraction and confocal laser scanning microscopy revealed that Fenton pretreatment disrupts the structure of SCB to facilitate the degradation of lignin by NaOH. The overall data suggest that this combinatorial strategy is a promising process for SCB pretreatment.