Welcome to Chemistry and Industry of Forest Products,

Chemistry and Industry of Forest Products ›› 2016, Vol. 36 ›› Issue (1): 20-26.doi: 10.3969/j.issn.0253-2417.2016.01.003

Previous Articles     Next Articles

Studies on Pyrolysis Process of β-O-4 Type Lignin Model Dimer Using Density Functional Theory

JIANG Xiao-yan, LU Qiang, DONG Xiao-chen, HU Bin, DONG Chang-qing   

  1. National Engineering Laboratory for Biomass Power Generation Equipment, Renewable Energy School, North China Electric Power University, Beijing 102206, China
  • Received:2014-12-29 Online:2016-02-25 Published:2016-03-18

Abstract: In order to understand the pyrolysis mechanism of lignin, 3-hydroxy-1-(4-hydroxyphenyl)-2-phenoxypropan-1-one with Cα carbonyl group was selected as a β-O-4 type lignin model dimer, and its pyrolysis process was theoretically calculated by density functional theory methods at B3LYP level with 6-31++G(d, p) basis set.The calculation results indicated that the carbonyl substituent on the Cα dramatically could significantly decrease the bond dissociation energy (EBD) of Cβ-O, while the bond dissociation energy of Cα-Cβ was augmented.The bond dissociation energy of Cβ-O was 91.5 kJ/mol lower than that of Cα-Cβ.Thus, it could be deduced that the dimer was mainly decomposed through the homolytic cleavage of the Cβ-O linkage, and major phenolic pyrolytic products of phenol and 4-hydroxybenzaldehyde, minor parts of 4-hydroxyacetophenone were formed in this process. The R7-a kinetic way was considered as the optimum way to form 4-hydroxybenzaldehyde, and the energy barrier was 236.6 kJ/mol.

Key words: lignin, β-O-4 linkage dimer, pyrolysis mechanism, density functional theory

CLC Number: