Co-production bioethanol and xylooligosaccharides from sugarcane bagasse via autohydrolysis pretreatment

Abstract

Autohydrolysis pretreatment is an effective, commercial and environmentally friendly processes for the co-production of bioethanol and xylooligosaccharides (XOS) from sugarcane bagasse (SCB). An XOS yield of 50.53% was obtained at 200 °C for 10 min by autohydrolysis pretreatment, most of cellulose and lignin remained in the solid residues, which can be converted into bioethanol. The ethanol yield (66.67%) in sodium acetate buffer solution (SAAB, pH 5.5) system was higher than that in the deionized water (DW) system (51.88%), because the stable pH regulated by the buffer was beneficial to maintain the cellulase and yeast activity. Moreover, the addition of non-ionic surfactants can effectively promote fermentation performances, especially with Tween 80, 82.28% ethanol yield (of the theoretical) was reached. The use of the buffer system and non-ionic surfactants provides an ideal strategy for ethanol production by fermentation of substrates with high lignin content. Therefore, this study shows a suitable and sustainable process for bioethanol and XOS production from SCB using autohydrolysis pretreatment as one-step of a biorefinery. • Autohydrolysis was an economical and feasible pretreatment method. • Bioethanol and XOS were co-produced from SCB via autohydrolysis pretreatment. • Buffer system was used for bioethanol production with high-lignin substrates. • Non-ionic surfactants can greatly increase fermentation performances. • 82.28% ethanol was produced from substrates with high lignin content.