Tian Zhenyu, Pitz William J, Fournet René, Glaude Pierre-Alexander, Battin-Leclerc Frédérique
Laboratoire Réactions et Génie des Procédés, CNRS, Nancy Université, ENSIC, 1, rue Grandville, BP 451, 54001 Nancy Cedex, France.
Proc Combust Inst. 2011 Jan;33(1):233-261. doi: 10.1016/j.proci.2010.06.063.
An improved chemical kinetic model for the toluene oxidation based on experimental data obtained in a premixed laminar low-pressure flame with vacuum ultraviolet (VUV) photoionization and molecular beam mass spectrometry (MBMS) techniques has been proposed. The present mechanism consists of 273 species up to chrysene and 1740 reactions. The rate constants of reactions of toluene decomposition, reaction with oxygen, ipso-additions and metatheses with abstraction of phenylic H-atom are updated; new pathways of C + C species giving benzene and fulvene are added. Based on the experimental observations, combustion intermediates such as fulvenallene, naphtol, methylnaphthalene, acenaphthylene, 2-ethynylnaphthalene, phenanthrene, anthracene, 1-methylphenanthrene, pyrene and chrysene are involved in the present mechanism. The final toluene model leads to an overall satisfactory agreement between the experimentally observed and predicted mole fraction profiles for the major products and most combustion intermediates. The toluene depletion is governed by metathese giving benzyl radicals, ipso-addition forming benzene and metatheses leading to CHCH radicals. A sensitivity analysis indicates that the unimolecular decomposition via the cleavage of a methyl C-H bond has a strong inhibiting effect, while decomposition via C-C bond breaking, ipso-addition of H-atom to toluene, decomposition of benzyl radicals and reactions related to CHCH radicals have promoting effect for the consumption of toluene. Moreover, flow rate analysis is performed to illustrate the formation pathways of mono- and polycyclic aromatics.
基于在预混层流低压火焰中利用真空紫外（VUV）光电离和分子束质谱（MBMS）技术获得的实验数据，提出了一种改进的甲苯氧化化学动力学模型。当前机理包含多达芘的273种物质和1740个反应。更新了甲苯分解、与氧反应、本位加成以及苯基氢原子夺取的复分解反应的速率常数；添加了碳碳物种生成苯和富烯的新途径。基于实验观察结果，当前机理涉及富烯丙二烯、萘酚、甲基萘、苊烯、2-乙炔基萘、菲、蒽、1-甲基菲、芘和芘等燃烧中间体。最终的甲苯模型使得主要产物和大多数燃烧中间体的实验观测和预测摩尔分数分布之间总体达成了令人满意的一致性。甲苯的消耗由生成苄基自由基的复分解反应、形成苯的本位加成反应以及生成CHCH自由基的复分解反应控制。敏感性分析表明，通过甲基碳氢键断裂的单分子分解具有很强的抑制作用，而通过碳碳键断裂的分解、氢原子对甲苯的本位加成、苄基自由基的分解以及与CHCH自由基相关的反应对甲苯的消耗具有促进作用。此外，进行了流速分析以阐明单环和多环芳烃的形成途径。
