Herbinet Olivier, Husson Benoit, Serinyel Zeynep, Cord Maximilien, Warth Valérie, Fournet René, Glaude Pierre-Alexandre, Sirjean Baptiste, Battin-Leclerc Frédérique, Wang Zhandong, Xie Mingfeng, Cheng Zhanjun, Qi Fei
Université de Lorraine, Laboratoire Réactions et Génie des Procédés, UPR 3349, Nancy, F-54000, France ; CNRS, Laboratoire Réactions et Génie des Procédés, UPR 3349, Nancy, F-54000, France.
Combust Flame. 2012 Dec;159(12):3455-3471. doi: 10.1016/j.combustflame.2012.07.008.
The low-temperature oxidation of -heptane, one of the reference species for the octane rating of gasoline, was investigated using a jet-stirred reactor and two methods of analysis: gas chromatography and synchrotron vacuum ultra-violet photo-ionization mass spectrometry (SVUV-PIMS) with direct sampling through a molecular jet. The second method allowed the identification of products, such as molecules with hydroperoxy functions, which are not stable enough to be detected using gas chromatography. Mole fractions of the reactants and reaction products were measured as a function of temperature (500-1100K), at a residence time of 2s, at a pressure of 800 torr (1.06 bar) and at stoichiometric conditions. The fuel was diluted in an inert gas (fuel inlet mole fraction of 0.005). Attention was paid to the formation of reaction products involved in the low temperature oxidation of -heptane, such as olefins, cyclic ethers, aldehydes, ketones, species with two carbonyl groups (diones) and ketohydroperoxides. Diones and ketohydroperoxides are important intermediates in the low temperature oxidation of n-alkanes but their formation have rarely been reported. Significant amounts of organic acids (acetic and propanoic acids) were also observed at low temperature. The comparison of experimental data and profiles computed using an automatically generated detailed kinetic model is overall satisfactory. A route for the formation of acetic and propanoic acids was proposed. Quantum calculations were performed to refine the consumption routes of ketohydroperoxides towards diones.
使用喷射搅拌反应器以及两种分析方法，即气相色谱法和通过分子束直接采样的同步辐射真空紫外光电离质谱法（SVUV-PIMS），对作为汽油辛烷值参考物质之一的正庚烷的低温氧化进行了研究。第二种方法能够鉴定出一些产物，比如带有氢过氧官能团的分子，这些分子稳定性较差，无法用气相色谱法检测。在2秒的停留时间、800托（1.06巴）的压力和化学计量条件下，测量了反应物和反应产物的摩尔分数随温度（500 - 1100K）的变化情况。燃料在惰性气体中稀释（燃料入口摩尔分数为0.005）。重点关注了正庚烷低温氧化过程中涉及的反应产物的形成，如烯烃、环醚、醛、酮、含有两个羰基的物质（二酮）和酮氢过氧化物。二酮和酮氢过氧化物是正构烷烃低温氧化过程中的重要中间体，但它们的形成情况鲜有报道。在低温下还观察到了大量的有机酸（乙酸和丙酸）。将实验数据与使用自动生成的详细动力学模型计算得到的曲线进行比较，总体结果令人满意。提出了乙酸和丙酸的形成途径。进行了量子计算，以优化酮氢过氧化物向二酮的消耗途径。
