FeCl3-catalyzed ethanol pretreatment of sugarcane bagasse boosts sugar yields with low enzyme loadings and short hydrolysis time

Abstract

An organosolv pretreatment system consisting of 60% ethanol and 0.025 mol·L−1 FeCl3 under various temperatures was developed in this study. During the pretreatment, the highest xylose yield was 11.4 g/100 g raw material, representing 49.8% of xylose in sugarcane bagasse. Structural features of raw material and pretreated substrates were characterized to better understand how hemicellulose removal and delignification affected subsequent enzymatic hydrolysis. The 160 °C pretreated solid presented a remarkable glucose yield of 93.8% for 72 h. Furthermore, the influence of different additives on the enzymatic hydrolysis of pretreated solid was investigated. The results indicated that the addition of Tween 80 shortened hydrolysis time to 6 h and allowed a 50% reduction of enzyme loading to achieve the same level of glucose yield. This work suggested that FeCl3-catalyzed organosolv pretreatment could improve the enzymatic hydrolysis significantly and reduce the hydrolysis time and enzyme dosage with the addition of Tween 80.