Bakali A El, Dupont L, Lefort B, Lamoureux N, Pauwels J F, Montero M
Physicochimie des Processus de Combustion et de l'Atmosphère, UMR CNRS 8522 PC2A, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France.
J Phys Chem A. 2007 May 17;111(19):3907-21. doi: 10.1021/jp067080z. Epub 2007 Apr 21.
Temperature and mole fraction profiles have been measured in laminar stoichiometric premixed CH4/O2/N2 and CH4/1.5%C6H5CH3/O2/N2 flames at low pressure (0.0519 bar) by using thermocouple, molecular beam/mass spectrometry (MB/MS), and gas chromatography/mass spectrometry (GC/MS) techniques. The present study completes our previous work performed on the thermal degradation of benzene in CH4/O2/N2 operating at similar conditions. Mole fraction profiles of reactants, final products, and reactive and stable intermediate species have been analyzed. The main intermediate aromatic species analyzed in the methane-toluene flame were benzene, phenol, ethylbenzene, benzylalcohol, styrene, and benzaldehyde. These new experimental results have been modeled with our previous model including submechanisms for aromatics (benzene up to p-xylene) and aliphatic (C1 up to C7) oxidation. Good agreement has been observed for the main species analyzed. The main reaction paths governing the degradation of toluene in the methane flame were identified, and it occurs mainly via the formation of benzene (C6H5CH3 + H = C6H6 + CH3) and benzyl radical (C6H5CH3 + H = C6H5CH2 + H2). Due to the abundance of methyl radicals, it was observed that recombination of benzyl and methyl is responsible for main monosubstitute aromatic species analyzed in the methane-toluene flame. The oxidation of these substitute species led to cyclopentadienyl radical as observed in a methane-benzene flame.
通过使用热电偶、分子束/质谱（MB/MS）和气相色谱/质谱（GC/MS）技术，在低压（0.0519巴）下测量了层流化学计量比预混CH4/O2/N2和CH4/1.5%C6H5CH3/O2/N2火焰中的温度和摩尔分数分布。本研究完善了我们之前在类似条件下运行的CH4/O2/N2中苯的热降解方面所做的工作。分析了反应物、最终产物以及反应性和稳定性中间物种的摩尔分数分布。在甲烷 - 甲苯火焰中分析的主要中间芳烃物种有苯、苯酚、乙苯、苯甲醇、苯乙烯和苯甲醛。这些新的实验结果已用我们之前的模型进行了模拟，该模型包括芳烃（苯到对二甲苯）和脂肪烃（C1到C7）氧化的子机制。对于所分析的主要物种，观察到了良好的一致性。确定了甲烷火焰中甲苯降解的主要反应路径，其主要通过苯（C6H5CH3 + H = C6H6 + CH3）和苄基自由基（C6H5CH3 + H = C6H5CH2 + H2）的形成而发生。由于甲基自由基的丰度，观察到苄基和甲基的重组是甲烷 - 甲苯火焰中所分析的主要单取代芳烃物种的原因。如在甲烷 - 苯火焰中所观察到的，这些取代物种的氧化导致了环戊二烯基自由基的形成。
