Studies on pyrolysis mechanism of syringol as lignin model compound by quantum chemistry

HUANG Jin-bao; LIU Chao; REN Li-rong; TONG Hong; LI Wei-min; WU Dan

Volume 41 Issue 06

Jun. 2013

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Article Navigation > Journal of Fuel Chemistry and Technology > 2013 > 41(06): 657-666

HUANG Jin-bao, LIU Chao, REN Li-rong, TONG Hong, LI Wei-min, WU Dan. Studies on pyrolysis mechanism of syringol as lignin model compound by quantum chemistry[J]. Journal of Fuel Chemistry and Technology, 2013, 41(06): 657-666.

Citation:

HUANG Jin-bao, LIU Chao, REN Li-rong, TONG Hong, LI Wei-min, WU Dan. Studies on pyrolysis mechanism of syringol as lignin model compound by quantum chemistry[J]. Journal of Fuel Chemistry and Technology, 2013, 41(06): 657-666.

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Studies on pyrolysis mechanism of syringol as lignin model compound by quantum chemistry

1.
School of Science, Guizhou Minzu University, Guiyang 550025, China;
2.
Key Laboratory of Low-Grade Energy Utilization Technologies and Systems of Ministry of Education, Chongqing University, Chongqing 400044, China;
3.
School of Chemistry and Environmental Science, Guizhou Minzu University, Guiyang 550025, China

Received Date: 2013-01-29
Rev Recd Date: 2013-03-18
Publish Date: 2013-06-30

Abstract

Abstract

The pyrolysis of syringol as lignin model compound was investigated using density functional theory methods at B3LYP/6-31G++ (d, p) level. Three possible pyrolytic pathways were proposed and the equilibrium geometries of the reactants, transition states, intermediate and products were fully optimized. The standard kinetic parameters in each reaction pathway were calculated and the formation and evolution mechanism of main pyrolysis products were analyzed. Bond dissociation energies calculation results show that the bond dissociation energy of CH₃-O of syringol is the lowest and the order of all kinds of bond dissociation energy is CH₃-O < O-H < CH₃O-C_aromatic < CH₂-H < HO-C_aromatic < C_aromatic-H. In reaction pathway 1 and 2, the main pyrolysis product is 3-methoxycatechol and 2-methoxy-6-methylphenol, respectively. The total energy barrier is 366.6 and 474.8 kJ/mol in pathway 1 and 2, respectively. For reaction pathway 3, the total energy barrier of o-methoxyphenol formation is as low as 21.4 kJ/mol, which shows that addition of hydrogen to the carbon atom connected with methoxyl can effectively lower the reaction energy barrier of demethoxy reaction of lignin model syringol.
- lignin,
- syringol,
- pyrolysis mechanism,
- density functional theory

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References(21)

References

MCKENDRY P. Energy production from biomass (part 1): Overview of biomass[J]. Bioresour Technol, 2002, 83(1): 37-46.

MAHINPEV N, MURUGAN P, MANI T, RAINA R. Analysis of bio-oil, biogas, and biochar from pressurized pyrolysis of wheat straw using a tubular reactor[J]. Energy Fuels, 2009, 23(5): 2736-2742.

黄金保, 刘朝, 曾桂生, 谢宇, 童红, 李伟民. 左旋葡聚糖热解机理的密度泛函理论研究[J]. 燃料化学学报, 2012, 40(7): 807-815. (HUANG Jin-bao, LIU Chao, ZENG Gui-sheng, XIE Yu, TONG Hong, LI Wei-min. A density functional theory study on the mechanism of levoglucosan pyrolysis[J]. Journal of Fuel Chemistry and Technology, 2012, 40(7): 807-815.)

黄金保, 童红, 李伟民, 伍丹. 木质素热解机理的分子动力学模拟研究[J]. 材料导报, 2012, 26(10): 138-142. (HUANG Jin-bao, TONG Hong, LI Wei-min, WU Dan. Molecular dynamic simulation study on thermal decomposition mechanism of lignin[J]. Materials Review, 2012, 26(10): 138-142.)

刘军利, 蒋剑春, 黄海涛. 木质素CP-GC-MS法裂解行为研究[J]. 林产化学与工业, 2009, 29(s): 1-6. (LIU Jun-li, JIANG Jian-chun, HUANG Hai-tao. Study on thermal transformations of lignin under curie-point pyrolysis-GC-MS conditions[J]. Chemisty and Industry of Forest Products, 2009, 29(s): 1-6.)

CABALLERO J A, FONT R, MARCILLA A. Study of the primary pyrolysis of kratf 1ignin at high heating rates: Yields and kineties[J]. J Anal Appl Pyrolysis, 1996, 36(2): 159-178.

谭洪, 王树荣, 骆仲泱, 余春江, 岑可法. 木质素快速热裂解试验研究[J]. 浙江大学学报(工学版), 2005, 39(5): 710-714. (TAN Hong, WANG Shu-rong, LUO Zhong-yang, YU Chun-jiang, CEN Ke-fa. Experimental study of lignin flash pyrolysis[J]. Journal Zhejiang University (Engineering Science), 2005, 39(5): 710-714.)

LIU Q, WANG S, ZHENG Y, LUO Z, CEN K. Mechanism study of wood lignin pyrolysis by using TG-FTIR analysis[J]. J Anal Appl Pyrolysis, 2008, 82(1): 170-177.

NUNN T R, HOWARD J B, LONGWLL J P, PETERS W A. Product compositions and kinetics in the rapid pyrolysis of milled wood lignin[J]. Ind Eng Chem Process Des Dev, 1985, 24(3): 844-852.

BESTE A, BUCHANAN III A C. Computational study of bond dissociation enthalpies for lignin model compounds: Substituent effects in phenethyl phenyl ethers[J]. J Org Chem, 2009, 74(7): 2837-2841.

HUANG X, LIU C, HUANG J, LI H. Theory studies on pyrolysis mechanism of phenethyl phenyl ether[J]. Comput Theor Chem, 2011, 976(1-3): 51-59.

蒋挺大. 木质素[M]. 北京: 化学工业出版社, 2001. (JIANG Ting-da. Lignin[M]. Beijing: Chemistry Industry Press, 2001.)

SURYAN M M, KAFAFI S A, STEIN S E. The thermal decomposition of hydroxy-and methoxy-substituted anisoles[J]. J Am Chem Soc, 1989, 111(4): 1423-1429.

DORRESTIJN E, MULDER P. The radical-induced decomposition of 2-methoxyphenol[J]. J Chem Soc Perkin Trans, 1999, (2): 777-780.

Gaussian 03. Gaussian, Inc. Pittsburgh PA, 2003.

HUANG J B, LIU C, TONG H, LI W M, WU D. Theoretical studies on pyrolysis mechanism of xylopyranose[J]. Computa Theore Chem, 2012, 1001: 44-50.

黄金保, 刘朝, 魏顺安, 黄晓露, 李豪杰. 纤维素热解形成左旋葡聚糖机理的理论研究[J]. 燃料化学学报, 2011, 39(8): 590-594. (HUANG Jin-bao, LIU Chao, WEI Shun-an, HUANG Xiao-lu, LI Hao-jie. A theoretical study on the mechanism of levoglucosan formation in cellulose pyrolysis[J]. Journal of Fuel Chemistry and Technology, 2011, 39(8): 590-594.)

张芳沛, 程新路, 刘子江, 胡栋, 刘永刚. 硝酸丙酯键离解能和热解机理的密度泛函理论研究[J]. 高压物理学报, 2005, 19(2): 189-192. (ZHANG Fang-pei, CHENG Xin-lu, LIU Zi-jiang, HU Dong, LIU Yong-gang. Density functional studies on the bond dissociation energy and pyrolysis mechanism of propyl nitrate[J]. Chinese Journal of High Pressure Physics, 2005, 19(2): 189-192.)

沈文浩, 陈小泉, 刘鸿斌, 武书彬. 木素模型物愈疮木酚结构和热解机理的量子化学研究[J]. 造纸科学与技术, 2010, 29(3): 73-78. (SHEN Wen-hao, CHEN Xiao-quan, LIU Hong-bin, WU Shu-bin. Quantum chemistry research on guaiacol lignin model compound structure and pyrolysis mechanism[J]. Paper Science & Technology, 2010, 29(3): 73-78.)

ASMADI M, KAWAMOTO H, SAKA S. Thermal reactions of guaiacol and syringol as lignin model aromatic nuclei[J]. J Anal Appl Pyrolysis, 2011, 92(1): 88-98.

ASMADI M, KAWAMOTO H, SAKA S. Thermal reactivities of catechols/pyrogallols and cresols/xylenols as lignin pyrolysis intermediates[J]. J Anal Appl Pyrolysis, 2011, 92(1): 76-87.

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