Production of cost-competitive bioethanol and value-added co-products from distillers' grains: Techno-economic evaluation and environmental impact analysis

• Published in: Bioresource technology 2024-04, Vol.397, p.130470-130470, Article 130470
• Main Authors: Zheng, Yuxi, Ngo, Huu Hao, Luo, Han, Wang, Ruxue, Li, Chun, Zhang, Chaolong, Wang, Xuliang
• Format: Article
• Language: English
• Subjects: Baijiu distillers' grains; Biorefinery; Cost-Benefit Analysis; Environment; Ethanol production; Extraction; Fermentation; Glucans; Greenhouse gas emissions; Lactic Acid
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2024.130470

[Display omitted] •Baijiu distillers' grains are exploited for biorefinery development.•Ethyl acetate extraction achieved complete lactic acid and glucan recovery.•The extraction of lactic acid and phenolics was followed by bioethanol production.•Techno-economic and life cycle analysis showed process sustainability. Here, Baijiu distillers' grains (BDGs) were employed in biorefinery development to generate value-added co-products and bioethanol. Through ethyl acetate extraction at a 1:6 solid–liquid ratio for 10 h, significant results were achieved, including 100 % lactic acid and 92 % phenolics recovery. The remaining BDGs also achieved 99 % glucan recovery and 81 % glucan-to-glucose conversion. Simultaneous saccharification and fermentation of remaining BDGs at 30 % loading resulted in 78.5 g bioethanol/L with a yield of 94 %. The minimum selling price of bioethanol varies from $0.149–$0.836/kg, contingent on the co-product market prices. The biorefinery processing of one ton of BDGs caused a 60 % reduction in greenhouse gas emissions compared to that of the traditional production of 88 kg corn-lactic acid, 70 kg antioxidant phenolics, 234 kg soybean protein, and 225 kg corn-bioethanol, along with emissions from BDG landfilling. The biorefinery demonstrated a synergistic model of cost-effective bioethanol production and low-carbon emission BDGs treatment.