Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.
Phys Chem Chem Phys. 2011 Dec 7;13(45):20262-74. doi: 10.1039/c1cp21663e. Epub 2011 Oct 12.
An automated reaction mechanism generator is used to develop a predictive, comprehensive reaction mechanism for the high-temperature oxidation chemistry of n-butanol. This new kinetic model is an advancement of an earlier model, which had been extensively tested against earlier experimental data (Harper et al., Combust. Flame, 2011, 158, 16-41). In this study, the model's predictive capabilities are improved by targeting isomer-resolved quantitative mole fraction profiles of flame species in low-pressure flames. To this end, a total of three burner-stabilized premixed flames are isomer-selectively analyzed by flame-sampling molecular-beam time-of-flight mass spectrometry using photoionization by tunable vacuum-ultraviolet synchrotron radiation. For most species, the newly developed chemical kinetic model is capable of accurately reproducing the experimental trends in these flames. The results clearly indicate that n-butanol is mainly consumed by H-atom abstraction with H, O, and OH, forming predominantly the α-C(4)H(9)O radical (CH(3)CH(2)CH(2)˙CHOH). Fission of C-C bonds in n-butanol is only predicted to be significant in a similar, but hotter flame studied by Oßwald et al. (Combust. Flame, 2011, 158, 2-15). The water-elimination reaction to 1-butene is found to be of no importance under the premixed conditions studied here. The initially formed isomeric C(4)H(9)O radicals are predicted to further oxidize by reacting with H and O(2) or to decompose to smaller fragments via β-scission. Enols are detected experimentally, with their importance being overpredicted by the model.
一种自动化反应机制生成器被用于开发正丁醇高温氧化反应的预测性、全面的反应机制。这个新的动力学模型是对早期模型的一个改进，该早期模型已经通过与早期的实验数据进行了广泛的测试（Harper 等人，《燃烧与火焰》，2011 年，158 卷，第 16-41 页）。在这项研究中，通过针对低压火焰中火焰物种的异构分辨定量摩尔分数分布来改进模型的预测能力。为此，总共使用可调谐真空紫外同步辐射光致电离，通过火焰取样分子束飞行时间质谱对三种燃烧器稳定的预混火焰进行了异构选择性分析。对于大多数物种，新开发的化学动力学模型能够准确地再现这些火焰中的实验趋势。结果清楚地表明，正丁醇主要通过 H 原子与 H、O 和 OH 的抽取消耗，主要形成α-C(4)H(9)O 自由基（CH(3)CH(2)CH(2)˙CHOH）。在 Oßwald 等人研究的类似但更热的火焰中，才预测到 n-丁醇中 C-C 键的断裂会显著发生（《燃烧与火焰》，2011 年，158 卷，第 2-15 页）。在研究的预混条件下，发现水消除反应生成 1-丁烯不重要。最初形成的异构 C(4)H(9)O 自由基预计通过与 H 和 O(2)反应进一步氧化，或者通过β断裂分解成较小的碎片。实验中检测到烯醇，其重要性被模型高估。
