Relationship of thermal degradation behavior and chemical structure of lignin isolated from palm kernel shell under different process severities
Relationship of thermal degradation behavior and chemical structure of lignin isolated from palm kernel shell under different process severities
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不同工艺强度下棕榈仁壳分离木质素的热降解行为与化学结构的关系
DOI：
10.1016/j.fuproc.2018.09.020
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发表时间：
2018-12-01
影响因子：
7.5
通讯作者：
Wang, Shurong
中科院分区：
文献类型：
--
作者：
Ma, Zhongqing;Wang, Junhao;Wang, Shurong
木质素因其芳香性而被认为是一种很有潜力的快速热解制备酚类化学品的原料。从棕榈仁壳中分离出4种不同程度的木质素：磨木木质素（MWL）、碱木质素（AL）、梅森木质素（KL）和有机溶剂乙醇木质素（OEL）。通过FTIR、GPC、2D-HSQC-NMR、TGA-FTIR和Py-GC/MS等分析手段，深入研究了Al的热解行为与化学结构的相关性，发现Al中β-O-4芳醚键含量最高（53.9/100 Ar），S/G值最高（1.68）。MWL由于其分子量的不均匀分布而显示出最宽的热降解温度范围（126-536 ℃）。含氧不凝性气体组分（H2O、CO2、CO）含量在AL中最高。木质素热解的主要有机组分为S型酚、G型酚、P型酚和C型酚。AL的酚类产物主要为G型（9.74-26.01%），KL的酚类产物主要为P型（44.23-56.01%），OEL的酚类产物主要为P型（29.38-56.07%），MWL的酚类产物主要为G型（9.08-25.81%）和P型（22.60-29.04%）。较高的热解温度有利于芳烃的生成。随着转化率从0.1增加到0.8，由DAEM模型估算的四种木质素的活化能均逐渐增大。
Lignin has been considered to be a potential feedstock to produce phenols chemicals by fast pyrolysis technology because of its aromaticity. In this work, four types of lignin were isolated from palm kernel shell with different severities: milled wood lignin (MWL), alkali lignin (AL), Mason lignin (KL), and organosolv ethanol lignin (OEL). A deep investigation of the relevance of the pyrolysis behaviors and chemical structure was carried out by FTIR, GPC, 2D-HSQC-NMR, TGA-FTIR and Py-GC/MS. AL contained highest content of beta-O-4 aryl ether bond (53.9/100 Ar) and highest value of S/G ratio (1.68). MWL showed the widest temperature range (126-536 degrees C) of thermal degradation because of its inhomogeneous distribution of molecular weight. Highest content of oxygencontaining non-condensable gas components (H2O, CO2, CO) was observed in AL. The dominant organic components from lignin pyrolysis were S-type phenols, G-type phenols, P-type phenols, and C-type phenols. G-type (9.74-26.01%) was the dominant phenols products in AL, while P-type (44.23-56.01%) for KL, P-type (29.38-56.07%) for OEL, and G-type (9.08-25.81%) and P-type (22.60-29.04%) in MWL. Higher pyrolysis temperature promoted the formation of aromatics. As the conversion rate increased from 0.1 to 0.8, the activation energy estimated from DAEM model of four types of lignin, all gradually increased.