Bioethanol from sugarcane bagasse: Focused on optimum of lignin content and reduction of enzyme addition. (June 2018)

• Record Type: Journal Article
• Authors: Yu, Na; Tan, Li; Sun, Zhao-Yong; Nishimura, Hiroto; Takei, Shouta; Tang, Yue-Qin; Kida, Kenji
• Is Part Of: Waste management. Volume 76(2018)
• Page Start: 404
• Page End: 413
• Publication Date: 2018-06
• Subjects: Sugarcane bagasse -- Lignin content -- Combination acid and alkali (CAA) pretreatment -- Fed-batch presaccharification-simultaneous saccharification and fermentation (P-SSF) -- Ethanol yield; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2018.03.047
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: SCB containing lignin of about 11% allows efficient conversion of SCB to ethanol. CAA pretreatment delignified SCB to lignin content of 11.7%. Ethanol concentration of 43.8 g/L was obtained after P-SSF of CAA-pretreated SCB. Fed-batch P-SSF reduced enzyme loading without affecting fermentation performance. Abstract: To investigate the effect of delignification on enzymatic saccharification and ethanol fermentation of sugarcane bagasse (SCB), NaClO, NaOH, and Na2 CO3 were used to prepare SCB with different lignin contents. We found that a lignin content of approximately 11% was sufficient for enzymatic saccharification and fermentation. Based on this result, an economical delignification pretreatment method using a combination of acid and alkali (CAA) was applied. Lignin content of 11.7% was obtained after CAA pretreatment with 0.5% w/v H2 SO4 at 140 °C for 10 min and 1.0% w/v NaOH at 90 °C for 60 min. Presaccharification-simultaneous saccharification and fermentation (P-SSF) of the CAA-pretreated SCB resulted in an ethanol concentration of 43.8 g/L and an ethanol yield of 81.7%, with an enzyme loading of 15 FPU/g–CAA-pretreated SCB. Enzyme activities (filter paper, carboxymethyl cellulase, and β -glucosidase activities) were determined in liquid phase during P-SSF, indicating that the residual cellulase activity could be further used. Thus, fed-batch P-SSF was carried out, and an ethanol concentration of 43.1 g/L and an ethanol yield of 80.4% were obtained with an enzyme loading of 10 FPU/g–CAA-pretreated SCB. Fed-batch P-SSF was found to be effective to reduce enzyme loading.