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ARTICLE

Formation Mechanism of Biomass Aromatic Hydrocarbon Tar on Quantum Chemistry

Bo Chen¹, Bo Liu^2,*, Yong Chao³, Chao Zhong¹

1 School of Mechanical Engineering, Hunan Institute of Engineering, Xiangtan, 411104, China
2 School of Electrical and Information Engineering, Hunan Institute of Engineering, Xiangtan, 411104, China
3 Hunan Shuanghuan Fiber Forming Equipment Co., Ltd., Xiangtan, 411100, China

* Corresponding Author: Bo Liu. Email:

(This article belongs to the Special Issue: New Trends in Bio-oil Production, Conversion and Utilization )

Journal of Renewable Materials 2022, 10(12), 3491-3504. https://doi.org/10.32604/jrm.2022.021302

Received 07 January 2022; Accepted 21 February 2022; Issue published 14 July 2022

Abstract

The formation process of aromatic hydrocarbon tar during the pyrolysis process of biomass components of cellulose and lignin was carried out by quantum chemical calculation based on density functional theory method B3LYP/6-31G++(d, p). 5-Hydroxymethylfurfural was chosen as the model compound of cellulose and hemicellulose, and syringaldehyde was chosen as the model compound of lignin. The calculation results show that the formation process of cellulose monocyclic aromatic hydrocarbon tar is the conversion process of benzene ring from furan ring, and the highest reaction energy barrier appears in the process of decarbonylation, which is 370.8 kJ/mol. The formation of lignin monocyclic aromatic hydrocarbon tar is mainly the process of side chains removal and the formation of phenol, The highest reaction energy barrier appears in the process of decarbonylation, which is 374.9 kJ/mol. The reaction mechanism of phenanthrene formation from naphthalene was selected as the formation of cellulose and lignin polycyclic aromatic hydrocarbon tar. The calculation results show that he total barrier of the pathway that naphthalene dehydrogenates to form naphthalene free radicals and then reacts with ethylene twice by addition action, finally occurs cyclization reactions and isomerizes to produce phenanthrene is lowest, that is 38.6 kJ/mol. So it is proved that the evolution of tar is the process of deoxygenation and cyclization with the increase of the temperature from a theoretical point of view.

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