Potassium Hydroxide-Mediated Pretreatment of Sugarcane Bagasse: High-Efficiency Enzymatic Hydrolysis and Excellent Sugar Recovery

Abstract

Sugarcane bagasse, an important by-product of the sugar industry, is the fibrous residue remaining from sugarcane stalks following the extraction of sugarcane juice. In this study, the efficacy of potassium hydroxide (KOH) pretreatment on sugarcane bagasse under mild conditions is examined, and its effectiveness was assessed through enzymatic saccharification at various solid loadings. After pretreatment with a KOH dosage of 15 wt.%, a solid–liquid ratio of 1:10, and reaction time at 90 °C for 2 h, enzymatic saccharification experiments were performed to observe the change rule for the sugar recovery yield. The results showed that the glucose concentration achieved 47.6 ± 1.1 g/L under optimal conditions. With a specified solid loading of 5% and an enzyme dosage of 20 FPU cellulase/g-substrate, the total sugar yield reached as high as 81.6 ± 1.1%. Additionally, the entire fermentable sugar production process was clean and sustainable, which is crucial for converting lignocelluloses to advanced bioenergy or chemicals.