Subcritical CO2 pretreatment of sugarcane bagasse and its enzymatic hydrolysis for sugar production

The present work investigated the effects of subcritical CO2 pretreatment of sugarcane bagasse at different CO2 pressure, pretreatment time, and temperature with relative high-solid concentration (15% w/v) to the composition of prehydrolyzate and the enzymatic hydrolysis. The results indicated that the maximum xylose yields in prehydrolyzate liquid were 15.78 g (combined 3.16 g xylose and 12.62 g xylo-oligosaccharides per 100 g raw material). Due to the effective removal of hemicellulose, the maximum glucose yield in enzyme hydrolyzate reached 37.99 g per 100 g raw material, representing 91.87% of glucose in the sugarcane bagasse. The maximal total sugars yield (combined xylose and glucose both in prehydrolyzate and enzymatic hydrolyzate) were 52.95 g based on 100 g raw material. These results indicated that subcritical CO2 pretreatment can effectively improve the enzymatic hydrolysis, so it could be successfully applied to sugarcane bagasse.