Computational study on pyrolysis mechanism of β-5 linked lignin dimers
Journal Title: Energy Environmental Protection - Year 2024, Vol 38, Issue 2
Abstract
Lignin is a highly complex amorphous three-dimensional network polymer connected by C—O bond and C—C bond. Understanding the bond cleavage mechanism during lignin pyrolysis is crucial for advancing efficient pyrolysis technology, as it serves as a significant avenue to harness lignin′s potential. In this paper, the density functional theory method was employed to investigate the process of alignin dimer model compound that contains β-5 linkages. The calculation results show that the most likely initial reaction is the five-membered ring-opening reaction between benzene rings, in which the bond dissociation energies (BDEs) of the Cα—O bond and Cα—Cβ bond are 163.9 kJ/ mol and 212.9kJ/ mol, respectively. These reactions are the main ring-opening reactions. By comparing the cleavage of β-5 linkages among the dimers that carry methyl, methoxy, hydroxyl, n-propyl, and other branched chains, it is found that the BDEs of the Cα—O bond and Cα—Cβ bond are at a minimum when hydroxyl, propyl, and hydroxymethyl groups are attached to the two benzene rings and the five-membered ring, respectively. Homolytic cleavage of the Cα—O bond is always the initial reaction, and the continuous fracture of the Cα—O and Cα—Cβ bonds is the main path to break the five-membered ring.
Authors and Affiliations
LI Wentao|Power China Northwest Engineering Corporation Limited, China, National Engineering Research Center of New Energy Power Generation, North China Electric Power University, China, GAO Lijuan|Power China Northwest Engineering Corporation Limited, China, ZHOU Guanzheng|National Engineering Research Center of New Energy Power Generation, North China Electric Power University, China, CHAI Baohua|Power China Northwest Engineering Corporation Limited, China, WANG Meijing|Power China Northwest Engineering Corporation Limited, China, HU Bin*|National Engineering Research Center of New Energy Power Generation, North China Electric Power University, China, LIU Ji|National Engineering Research Center of New Energy Power Generation, North China Electric Power University, China, LU Qiang|National Engineering Research Center of New Energy Power Generation, North China Electric Power University, China
Keywords
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- EP ID EP737163
- DOI 10.20078/j.eep.20240104
- Views 46
- Downloads 1
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