Wang Fang, Yu You-Zhu, Chen Yigang, Yang Chun-Yu, Yang Yuan-Yu
Department of Chemical and Environmental Engineering, Anyang Institute of Technology, Anyang 455000, China.
Key Laboratory of Magnetic Molecules and Magnetic Information Material of Ministry of Education, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, China.
Biotechnol Rep (Amst). 2019 Jul 30;24:e00363. doi: 10.1016/j.btre.2019.e00363. eCollection 2019 Dec.
Lignin valorization is a challenge because of its complex structure and high thermal stability. Supercritical alcoholysis of lignin without external hydrogen in a self-made high-pressure reactor is investigated under different temperatures (450-500 °C) and solvents as well as catalysts by using a reactant suspension mode. Small-molecular arenes and mono-phenols (C-C) are generated under short residence time of 30 min. High temperature (500 °C) favors efficient deoxy-liquefaction of lignin (70%) and formation of small-molecular arenes (C-C). Solvents methanol and ethanol demonstrate much more synergistic effect on efficient deoxy-liquefaction of lignin than propanol. The catalyst Cu-C has the optimal activity and selectivity in methanol (70% of conversion, 83.93% of arenes), whereas Fe-SiC possesses the optimal catalytic deoxygenation in ethanol, resulting in the formation of arenes other than phenols. Further analysis indicates that lignin is converted into arenes by efficient cleavages of C-O ether bonds and C-C bonds under high temperature and pressure.
由于木质素结构复杂且热稳定性高，其增值利用具有挑战性。在自制的高压反应器中，采用反应物悬浮模式，研究了在不同温度（450 - 500°C）、溶剂以及催化剂条件下，木质素在无外部氢气情况下的超临界醇解反应。在30分钟的短停留时间内生成了小分子芳烃和单酚（C-C）。高温（500°C）有利于木质素的高效脱氧液化（70%）以及小分子芳烃（C-C）的形成。与丙醇相比，溶剂甲醇和乙醇对木质素的高效脱氧液化表现出更强的协同效应。催化剂Cu-C在甲醇中具有最佳活性和选择性（转化率70%，芳烃含量83.93%），而Fe-SiC在乙醇中具有最佳催化脱氧性能，导致生成除酚类以外的芳烃。进一步分析表明，在高温高压下，木质素通过C-O醚键和C-C键的有效断裂转化为芳烃。
