Effects of Hydrothermal Reaction of Sulfuric Acid Lignin from Cryptomeria japonica for Industrial Utilization
Effects of Hydrothermal Reaction of Sulfuric Acid Lignin from Cryptomeria japonica for Industrial Utilization
复制标题
DOI：
10.15376/biores.13.4.7805-7825
复制
发表时间：
2018-01-01
期刊：
影响因子：
1.5
通讯作者：
Fukushima, Kazuhiko
中科院分区：
文献类型：
--
作者：
Liu, Qiang;Matsushita, Yasuyuki;Fukushima, Kazuhiko
硫酸木质素（SAL）是用于生产生物燃料的木质纤维素材料酸糖化过程中产生的主要生物精炼工业残留物之一，正在成为生物精炼工业可持续发展的主要问题。同时，SAL的顽固性和高度复杂的结构使其不溶于水和其他有机溶剂，导致反应活性较低。本研究研究了水热反应对 SAL 的影响，以提高其溶解度和反应性。首先对来自日本柳杉的SAL进行水热反应以获得完全水溶性的木质素。傅里叶变换红外光谱、凝胶渗透色谱、气相色谱和核磁共振（NMR）分析表明，SAL 的水热反应引起解聚、去甲基化和酚羟基的引入。此外，还进行了另一项实验，合成芳环上带有C-13标记的木质素聚合物模型化合物（DHP），然后进行水热反应和乙酰化。通过固态交叉偏振魔角旋转核磁共振分析获得了水热反应下 DHP 的详细结构信息。水热反应通过缩合木质素单元中酚羟基/脂肪族羟基比率的反向增加而增强了水热处理的SAL的反应性。
Sulfuric acid lignin (SAL), one of the major biorefinery industry residues from the acid saccharification process on lignocellulosic materials for bio-fuel generation, is becoming a major problem for the sustainable development of the bio-refinery industry. Meanwhile, the recalcitrant and highly complex structure of SAL makes it insoluble in water and other organic solvents, resulting in a low reactivity. This study investigated the effects of hydrothermal reactions on SAL to enhance its solubility and reactivity. A hydrothermal reaction was first conducted on SAL from Cryptomeria japonica to obtain a completely water-soluble lignin. Fourier transform infrared spectroscopy, gel permeation chromatography, gas chromatography, and nuclear magnetic resonance (NMR) analyses revealed that the hydrothermal reaction of the SAL caused depolymerisation, demethylation, and the introduction of phenolic hydroxyls. Furthermore, another experiment was conducted on synthesizing a lignin polymer model compound (DHP) with C-13-labelled on the aromatic ring, followed by hydrothermal reaction and acetylation. Detailed structural information of DHP under hydrothermal reaction was obtained by solid-state cross polarization magic angle spinning NMR analysis. Reactivity of the hydrothermally treated SAL was enhanced by the hydrothermal reaction through the reversed increasing of the phenolic hydroxyl/aliphatic hydroxyl ratio in the condensed lignin units.