A novel green biorefinery strategy for corn stover by pretreatment with weak alkali-assisted deep eutectic solvents

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 26; no. 4; pp. 23 - 2312
• Main Authors: Wang, Zhaobao, Zhou, Jie, Yin, Yating, Mu, Mengqian, Liu, Yanzhou, Zhou, Disheng, Wang, Weitao, Zuo, Xinyun, Yang, Jianming
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 19.02.2024
• Subjects: Antimony; Biomass; Biorefineries; Carbohydrates; Corn; Digestibility; Fractionation; Glucose; Lignin; Low molecular weights; Mass balance; Molecular weight; NMR; Nuclear magnetic resonance; Pretreatment; Refining; Sodium bicarbonate; Solvents; Stover; Thermal stability; Utilization; Xylose
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/d3gc04091g

Green and efficient biorefinery strategies are essential for sustainable biomass utilization. This study reported a novel fractionation strategy using deep eutectic solvent-sodium bicarbonate (DES-SB) for full-component utilization of corn stover (CS). The results showed that the addition of SB significantly improved the delignification efficiency (90.03%) compared to that of the neat DES pretreatment (34.64%). As a result, excellent carbohydrate digestibility was achieved (glucose yield, 97.47%; xylose yield, 92.93%). Moreover, the regenerated lignin exhibited high purity (94.31%), excellent thermal stability, a low molecular weight (1593 g mol −1 ), and good uniformity (1.76), indicating great potential for further value enhancement. NMR analysis indicated the retention of major interunit linkages (45.6% of β-O-4), and the recovered lignin presented a greater number of carboxyl groups and a lower number of p -hydroxyphenyl OH groups as the pretreatment severity increased. Finally, mass balance analysis demonstrated that 1 kg of dry CS could produce 367.03 g of glucose, 171.70 g of xylose, and 143.52 g of lignin. Overall, this study provides a green, high-efficiency, and synergistic DES-SB pretreatment strategy that has great potential for full-component biomass utilization and sustainable industrial biorefinery application. The strategy using deep eutectic solvent-sodium bicarbonate (DES-SB) has achieved a high delignification efficiency, excellent carbohydrate digestibility (glucose yield, 97.47%; xylose yield, 92.93%), and regenerated lignin with great potential.