Non-digesting strategy for efficient bioconversion of cassava to bioethanol via mechanical activation and metal salts pretreatment. (May 2021)

• Record Type: Journal Article
• Authors: Zhang, Yanjuan; Li, Wanhe; Huang, Min; Xu, Xiaofen; Jiang, Min; Hu, Huayu; Huang, Zuqiang; Liang, Jing; Qin, Yuben
• Is Part Of: Renewable energy. Volume 169(2021)
• Page Start: 95
• Page End: 103
• Publication Date: 2021-05
• Subjects: Cassava -- Bioethanol -- Bioconversion -- Non-digesting -- Mechanical activation -- Metal salt; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.12.138
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: This study focused on the development of an efficient technology for bioconversion of cassava to bioethanol without high temperature digesting. Mechanical activation (MA, ball milling)-metal salt (MA-MS) technology was applied to pretreat cassava flour, leading to significant changes in crystal structure, morphology, and viscosity. The destruction of stable structure of cassava flour induced by MA-MS pretreatment increased the accessibility of glucoamylase to starch granules from surface to interior, which contributed to direct and efficient saccharification of cassava flour without digesting. The decrease in viscosity of slurry and the use of metal salt as nutrient for yeast ( Saccharomyces cerevisiae ) had favorable effect on fermentation process. The combination of MA and MgSO4 exhibited outstanding synergistic interaction. The ethanol concentration and conversion efficiency of MA-MgSO4 pretreated cassava flour achieved 13.64 vol% and 93.4% under optimum conditions (addition amount of MgSO4 = 6 wt%, MA time = 75 min, dosage of glucoamylase = 200 U/g cassava, and dosage of Saccharomyces cerevisiae = 0.3 wt%). MA-MS pretreatment significantly enhanced the saccharification and fermentation processes for efficient bioconversion of cassava to bioethanol by non-digesting strategy. Graphical abstract: Image 1 Highlights: Effective mechanical activation-metal salt (MA-MS) pretreatment for cassava. The disruption of stable structure resulted in direct saccharification of cassava. .►The decrease in viscosity and metal salt as nutrient led to efficient fermentation. MA-MgSO4 exhibited outstanding synergistic effect to achieve excellent efficiencies. The highest total conversion efficiency of 93.4% for MA-MgSO4 pretreated cassava.