Insights into Structural Changes of Lignin toward Tailored Properties during Deep Eutectic Solvent Pretreatment
Insights into Structural Changes of Lignin toward Tailored Properties during Deep Eutectic Solvent Pretreatment
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DOI：
10.1021/acssuschemeng.0c01361
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发表时间：
2020-07-06
影响因子：
8.4
通讯作者：
Wan, Caixia
中科院分区：
文献类型：
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作者：
Chen, Zhu;Bai, Xianglan;Wan, Caixia
生物质预处理使得能够提取具有所需特性（特别是保存良好的β-O-4键）的木质素，同时确保改善纤维素消化率仍然是可持续生物精炼的挑战。本研究旨在解决这一挑战，使用深共熔溶剂（DES），包括氯化胆碱和乙二醇（氯化胆碱/EG）柳枝稷分馏。对提取的DES木质素进行了广泛的表征，以了解木质素的性质，包括纯度、分子量、热稳定性和β-O-4键的丰度，在不同的预处理条件下在DES中是如何改变的。微调溶剂系统将引导基于DES的生物质分馏朝向同步未冷凝木质素和可消化纸浆的生产。吸引人的木质素特性，如高纯度（91.4%），保存良好的β-O-4键，和类似于纤维素分解酶木质素（CEL）的高挥发性，是在这种设计师的溶剂系统中获得的。至少65%的木质素可以被去除，最高的脱木质素在30分钟内达到近90%。总体而言，这种通用的和可调的DES系统是有前途的木质纤维素生物质加工，并将适合于不同的生物炼制配置对增值的木质纤维素生物质的价值。
Biomass pretreatment enabling extraction of lignin with desirable properties (especially well-preserved beta-O-4 linkages) while ensuring improved cellulose digestibility remains a challenge for sustainable biorefinery. This study aimed to address this challenge using a deep eutectic solvent (DES) comprising choline chloride and ethylene glycol (ChCl/EG) for switchgrass fractionation. Extensive characterization of extracted DES lignin was performed to understand how the lignin properties, including purity, molecular weight, thermal stability, and abundance of the beta-O-4 linkages, were changed in the DESs under varied pretreatment conditions. Finely tuning the solvent system would steer DES-based biomass fractionation toward synchronizing the production of uncondensed lignin and digestible pulp. Appealing lignin properties, such as high-purity (91.4%), well-preserved beta-O-4 linkages, and high volatility similar to that of cellulolytic enzyme lignin (CEL), is obtainable in this designer solvent system. At least 65% lignin can be removed, with the highest delignification reaching near 90% within 30 min. Overall, this versatile and tunable DES system is promising for lignocellulosic biomass processing and would fit into different biorefinery configurations toward value-added valorization of lignocellulosic biomass.