Acid-based deep eutectic solvents (ADES) have recently been tested as an emerging technology in biomass deconstruction. In particular, the use of hemicellulose-derived carboxylic acids has attracted great interest as this type of ADES can enable a sustainable closed-loop biorefinery, due to their efficiency and recyclability. Therefore, this study proposed the pretreatment of sugarcane bagasse (SCB) with acetic acid, as a biomass-derived chemical, and choline chloride [ChCl]:AA to perform a complete biomass fractionation to enhance enzymatic digestibility. Thus, this work analyzed the effect of different temperatures and reaction time during pretreatment, studying the impact on biomass composition and digestibility during enzymatic hydrolysis. In addition, the reuse of ADES to produce an environmentally friendly and low-cost SCB biorefinery was explored by studying the physicochemical modifications in polysaccharide-rich material (PRM) and lignin-rich material (LRM) by ATR-FTIR and SEM photography. Furthermore, the ADES content was also characterized by HPLC after each recycling cycle. The results demonstrated efficient polysaccharide conversion, promoting an enrichment in glucan (>60%) and xylan (>20%) content under mild operating conditions (130°C and 90 min) supported by ATR-FTIR and . Furthermore, SCB pretreated under these selected conditions achieved higher digestibility, increasing by 89% for glucan and 73% for xylan, using a simple and competitive process. In contrast, increasing the temperature above 130°C did not improve the enzymatic digestibility of SCB. Thus, ChCl:AA could be recycled and reused. Therefore, this study demonstrated the potential of AA in DES pretreatments as an environmentally friendly and efficient method for the valorization of SCB components.

中文翻译：

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使用来自半纤维素衍生酸的更环保的低共熔溶剂开发可持续的甘蔗渣生物精炼厂


酸基低共熔溶剂 (ADES) 最近作为生物质解构的新兴技术进行了测试。特别是，半纤维素衍生的羧酸的使用引起了极大的兴趣，因为这种类型的 ADES 因其效率和可回收性而可以实现可持续的闭环生物精炼。因此，本研究提出用乙酸（一种生物质衍生化学品）和氯化胆碱 [ChCl]:AA 对甘蔗渣 (SCB) 进行预处理，以进行完整的生物质分馏，以提高酶消化率。因此，本工作分析了预处理过程中不同温度和反应时间的影响，研究了酶水解过程中对生物质组成和消化率的影响。此外，通过ATR-FTIR和SEM摄影研究富含多糖材料（PRM）和富含木质素材料（LRM）的物理化学修饰，探索了重复利用ADES来生产环境友好且低成本的SCB生物精炼。此外，每次回收循环后，ADES 含量也通过 HPLC 进行表征。结果表明，在 ATR-FTIR 和 .此外，在这些选定条件下进行预处理的 SCB 使用简单且具有竞争力的工艺实现了更高的消化率，葡聚糖提高了 89%，木聚糖提高了 73%。相反，将温度提高到 130°C 以上并不能提高 SCB 的酶消化率。因此，ChCl:AA 可以回收和再利用。 因此，本研究证明了 AA 在 DES 预处理中作为一种环境友好且有效的 SCB 成分增值方法的潜力。