State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
Bioresour Technol. 2015 Apr;182:120-127. doi: 10.1016/j.biortech.2015.01.127. Epub 2015 Feb 7.
Four lignin polymers, alkali lignin (AL), klason lignin (KL), organosolv lignin (OL), and milled wood lignin (MWL), were isolated from the same pine wood. Structural characterization by FTIR and (13)C NMR indicated that the four lignins have different structural features. Their pyrolysis behaviors were analyzed by TG-FTIR and Py-GC/MS. Thermally unstable ether bonds and side branches were well-preserved in AL and MWL, but were broken in OL and KL. Pyrolysis of AL and KL produce more phenols at low temperature by the breakage of ether bonds. AL and KL show lower activation energies in the main degradation stage, quantified by a distribution activation energy model with two linearly combined Gaussian functions. The evolution behaviors of typical gaseous products, CH4, CO2, and CO, were analyzed, and insights about the correlation between chemical structure and pyrolysis behavior were obtained.
四种木质素聚合物，即碱木质素（AL）、Klason 木质素（KL）、有机溶剂木质素（OL）和磨木木质素（MWL），均从同一松木中分离得到。通过傅里叶变换红外光谱（FTIR）和（13）C 核磁共振（NMR）对其结构进行了表征，结果表明这四种木质素具有不同的结构特征。通过热重-傅里叶变换红外光谱联用（TG-FTIR）和热解气相色谱-质谱联用（Py-GC/MS）分析了它们的热解行为。在 AL 和 MWL 中，热不稳定的醚键和侧链得以很好地保留，但在 OL 和 KL 中则被破坏。通过醚键的断裂，AL 和 KL 在低温下会产生更多的酚类物质。通过分布活化能模型（用两个线性组合的高斯函数）定量分析，AL 和 KL 在主降解阶段的活化能较低。分析了典型气态产物 CH4、CO2 和 CO 的演化行为，获得了关于化学结构与热解行为之间相关性的见解。
