Enhancing enzyme hydrolysis of Sorghum stalk by CO 2 ‐pressurized liquid hot water pretreatment

• Published in: Environmental Progress & Sustainable Energy
• Main Authors: Zhao, Meng‐Jiao, Xu, Qin‐Qin, Zhen, Meng‐Yuan, Li, Guo‐Min, Gang‐Xu, Yin, Jian‐Zhong
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/ep.12426; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fep.12426; http://onlinelibrary.wiley.com/wol1/doi/10.1002/ep.12426/fullpdf

CO 2 ‐pressurized liquid hot water was applied to pretreat Sorghum stalk to increase its accessibility for enzyme hydrolysis. Pretreatment temperatures tested ranged from 180 to 220°C, and reaction times varied between 10 and 30 min. The highest total reducing sugar yield of 81.54% was obtained for the sample pretreated at 200°C and 20 min. Different from the N 2 ‐pressurized liquid hot water process, the generated carbonic acid in the CO 2 ‐pressurized method acted as catalyst in the pretreatment process. It was found that the reducing sugar yield increased significantly at lower temperature and shorter reaction time with the addition of CO 2 . Finally, X‐ray diffraction and scanning electron microscope analysis were used to investigate the microstructure of the Sorghum stalk before and after the pretreatment. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 208–213, 2017