Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China.
Bioresour Technol. 2013 Jan;128:633-9. doi: 10.1016/j.biortech.2012.10.148. Epub 2012 Nov 8.
Structural characteristics of benzene-ethanol-extracted lignin (BEL) and acetone-extracted lignin (AL) precipitated from black liquor were identified by elemental analysis, FTIR, (13)C NMR, and (1)H NMR, while the thermal behaviors were examined with thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR). The frequency of β-O-4 bonds per 100 C9 monomeric units was 28 and 17 for BEL and AL. Two-stage pyrolysis processes were observed for the two lignins. The mass loss rate of the initial solvent evolution stage (110-180 °C) of BEL was greater than that of AL. The two lignins presented slightly different mass loss curves and evolution profiles of gases in the main pyrolysis stage (280-500 °C). A global kinetic model was proposed for lignin pyrolysis and activation energies of 39.5 and 38.8 kJ/mol was obtained for BEL and AL. The results enhance understanding of lignin pyrolysis and facilitate commercial utilization of black-liquor lignin.
采用元素分析、FTIR、(13)C NMR 和 (1)H NMR 对从黑液中沉淀得到的苯乙醇提取木质素 (BEL) 和丙酮提取木质素 (AL) 的结构特征进行了鉴定，同时采用热重-傅里叶变换红外光谱 (TG-FTIR) 对其热行为进行了研究。BEL 和 AL 的每 100 个 C9 单体单元中β-O-4 键的频率分别为 28 和 17。两种木质素均观察到两阶段热解过程。BEL 初始溶剂挥发阶段 (110-180°C) 的质量损失速率大于 AL。在主热解阶段 (280-500°C) ，两种木质素的质量损失曲线和气体演化谱略有不同。提出了一个用于木质素热解的全局动力学模型，得到 BEL 和 AL 的活化能分别为 39.5 和 38.8 kJ/mol。研究结果加深了对木质素热解的理解，有利于黑液木质素的商业化利用。
