Co-production of fermentable sugars and highly active lignin from eucalyptus via a mild preprocessing with diethylene glycol and chromic chloride

• Published in: International journal of biological macromolecules 2024-07, Vol.273 (Pt 2), p.133161, Article 133161
• Main Authors: Tang, Song, Yuan, Shen-ao, Sheng, Yequan, Tan, Xin, Zhang, Qin, Dong, Qian, Wang, Yuanli, Zhou, Fei, Li, Jun, Yu, Yan-ling
• Format: Article
• Language: English
• Subjects: Chromic chloride; Diethylene glycol; Eucalyptus; Fermentable sugar; High activity lignin; Lignocellulose pretreatment
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.133161

Eucalyptus was pretreated with diethylene glycol catalyzed by 0.02 mol/L CrCl3 for 10 min, resulting in 91 % delignification and 98 % cellulose recovery, with trace fermentation inhibitors generated. After the mild pretreatment, the accessibility and affinity of cellulase to eucalyptus was enhanced, especially since enzyme adsorption rate increased by 1.6-fold. Therefore, glucose yield of pretreated eucalyptus was 7.9-fold higher than that of untreated eucalyptus after hydrolyzed 48 h, in which the maximum glucose concentration reached 62 g/L from eucalyptus by adding Tween 80. According to the characterization analysis, the structure of the eucalyptus lignin-carbohydrate complexes structure was destroyed during the pretreatment, while lignin fragments was likely reacted with diethylene glycol to form the stabilized aromatic ethers. Moreover, the extracted Deg-lignin exhibited better performances than commercial alkali lignin such as higher fluorescence intensity, less negative surface charge, and lower particle size. The mild pretreatment method with diethylene glycol and CrCl3 provided a promising approach for co-production of fermentable sugars and high activity lignin from lignocellulosic biomass. [Display omitted] •Efficient separation of eucalyptus by Deg and CrCl3 achieved under mild conditions.•Lignin underwent grafting reaction with diethylene glycol during the pretreatment.•The extracted Deg-lignin shown super performances than commercial alkali lignin.•Glucose yield of eucalyptus increased by 6.9-fold after Deg-CrCl3 pretreatment.•Adding Tween 80 reduced half of hydrolysis time for high-concentrated enzymolysis.