Fractionation of Poplar Wood Using a Bifunctional Aromatic Acid under Mild Conditions
Fractionation of Poplar Wood Using a Bifunctional Aromatic Acid under Mild Conditions
复制标题
DOI：
10.1021/acssuschemeng.1c00123
复制
发表时间：
2021-04-02
影响因子：
8.4
通讯作者：
Yang, Qiang
中科院分区：
文献类型：
--
作者：
He, Duo;Zhuang, Jingshun;Yang, Qiang
开发节能的分级工艺以及保留分级的纤维素、半纤维素糖和木质素是木质纤维素增值的关键。本研究提出了一种温和的条件下分馏过程的基础上可回收的和双功能的4-氯苯磺酸（4-Cl-BSA）。水性（例如，72%4-Cl-BSA溶液在50-80 ℃下几乎完全分级分离未研磨的白杨碎片18-180分钟，并连续保持分级纤维素、木质素和半纤维素糖的理论最大产率和关键结构。约21.3-27.8%的木质素通过与4-Cl-BSA及其聚集体的聚集和络合而在中尺度水平上水溶溶解。溶解的木质素保留了天然木质素中约24.7-50.7%的61%的β-O-4键和约48.3-82%的未缩合芳族单元。约72.2-78.7%的木质素是不溶的，并迅速沉积在纤维素纤维表面。值得注意的是，沉积的木质素保留了天然木质素中约61.9-81.1%的β-O-4键和约78.2-86.2%的未缩合芳族单元。半纤维素糖和纤维素（mm级，CrI：71-75，DPv：910-1022）纯度高，质量好。与其他选择的芳基磺酸相比，无论它们是否具有取代基（二氯，溴，羟基和甲基）和无机酸，4-Cl-BSA在分馏未研磨的白杨碎片和保留木质素的β-O-4键和芳香族单元方面表现更好。结果表明，芳基磺酸的酸性和疏水性对其分离和保存性能有很大影响。
The development of an energy-efficient fractionation process as well as the preservation of the fractionated cellulose, hemicellulose sugars, and lignin are the key to the valorization of lignocellulose. This study presents a mild-condition fractionation process based on a recyclable and bifunctional 4-chlorobenzenesulfonic acid (4-Cl-BSA). The aqueous (e.g., 72%) 4-Cl-BSA solution near-completely fractionated unmilled poplar chips at 50-80 degrees C for 18-180 min and successively preserved the theoretical maximum yields and key structures of the fractionated cellulose, lignin, and hemicellulose sugars. Around 21.3-27.8% lignin was hydrotropically dissolved at a mesoscale level through accumulation by and complexation with 4-Cl-BSA and its aggregates. The solubilized lignin preserved about 24.7-50.7% of the 61% beta-O-4 linkages in the native lignin and about 48.3-82% aromatic units uncondensed. About 72.2-78.7% lignin was insolubilized and quickly deposited on the surfaces of cellulose fibers. Remarkably, the deposited lignin preserved about 61.9-81.1% of the beta-O-4 linkages in the native lignin and about 78.2-86.2% aromatic units uncondensed. Hemicellulose sugars and cellulose (millimeter-size, CrI: 71-75, DPv: 910-1022) had high purity and high quality. Compared to the other selected aryl sulfonic acids whether they have or do not have substituents (dichloro, bromo, hydroxyl, and methyl) and mineral acids, 4-Cl-BSA performed better in fractionating unmilled poplar chips and preserving the beta-O-4 linkages and aromatic units of lignin. The results indicate that both acidity and hydrophobicity of aryl sulfonic acid greatly influence its fractionation and preservation performances.