Simultaneous Pretreatment with Ultraviolet Light and Alkaline H2O2 to Promote Enzymatic Hydrolysis of Corn Stover

Pretreatment processes are essential for the preparation of biofuels from lignocellulosic feedstocks. Based on alkaline H2O2 pretreatment, photocatalytic alkaline H2O2 pretreatment (U-AHP) was investigated to examine the effects of reaction time, alkali concentration, and H2O2 concentration on the enzymatic digestion of corn stover. The optimum process conditions were determined by orthogonal tests: 1% NaOH, 2% H2O2, and reaction time of 8 h. Under these conditions, the lignin removal efficiency of UH-AHP was 90.2% and the saccharification yield was 94.7%. Furthermore, FT-IR, XRD, and SEM analyses showed that U-AHP pretreatment caused structural damage to the maize straw and increased the crystallinity of the cellulose, and it was speculated that the U-AHP pretreatment reaction was a complex mechanism, which might be a multiple synergistic reaction. This study shows that U-AHP pretreatment is a simple, green and effective method to promote lignin removal.