Experimental and detailed kinetic modeling study of the high pressure oxidation of methanol sensitized by nitric oxide and nitrogen dioxide
Experimental and detailed kinetic modeling study of the high pressure oxidation of methanol sensitized by nitric oxide and nitrogen dioxide
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DOI：
10.1016/j.proci.2006.07.143
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
G. Dayma;K. Ali;P. Dagaut
中科院分区：
文献类型：
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作者：
G. Dayma;K. Ali;P. Dagaut
NOx 对燃烧的扰动在一些实际系统中很重要（最近的 NOx 还原策略、柴油和 HCCI 发动机中的废气再循环燃烧以及轻度燃烧）。在 10 个大气压、700-1100K 温度范围内运行的熔融石英喷射搅拌反应器中，在不存在和存在 NO 或 NO2 的情况下，甲醇的氧化获得了新的实验结果。探针取样后进行在线 FTIR 分析和离线 GC-TCD/FID 分析，可以测量反应物、稳定中间体和最终产品的浓度分布。对本实验进行了详细的化学动力学建模。当前数据与该模型之间总体上吻合良好。 NO2 显着促进甲醇的氧化，而 NO 的作用则较为有限。根据所提出的模型，甲醇和NO 氧化的相互敏化是通过HO2 将NO 转化为NO2 进行的。 HO2 氧化 NO 导致 OH 生成量增加，从而促进燃料的氧化。对于甲醇的 NO 种子氧化，可以提出一个简化的反应方案：NO+HO2⇒NO2+OH，然后是 OH+CH3OH⇒H2O+CH2OH 和 CH3O。通过添加 NO2 增强甲醇的氧化也是由于通过以下方式产生额外的 OH：NO2+HO2⇒HONO+O2、NO2+H⇒NO+OH 和 HONO⇒NO+OH，然后是 OH+CH3OH⇒CH2OH 和 CH3O。进一步反应 CH2OH+O2⇒CH2O+HO2； CH3O⇒CH2O+H； CH2O+OH⇒HCO；无论添加 NO 还是 NO2，HCO+O2⇒HO2 和 H+O2⇒HO2 都完成该序列。
The perturbation of the combustion by NOxis important in several practical systems (recent NOx-reduction strategies, combustion with exhaust-gas recirculation in diesel and HCCI engines and for mild combustion). New experimental results were obtained for the oxidation of methanol in absence and in presence of NO or NO2in a fused silica jet-stirred reactor operating at 10atm, over the temperature range 700–1100K. Probe sampling followed by on-line FTIR analyses and off-line GC-TCD/FID analyses permitted to measure the concentration profiles of the reactants, stable intermediates and the final products. A detailed chemical kinetic modeling of the present experiments was performed. An overall good agreement between the present data and this modeling was obtained. The oxidation of methanol is significantly sensitized by NO2, whereas the effect of NO is more limited. According to the proposed model, the mutual sensitization of the oxidation of methanol and NO proceeds through the NO to NO2conversion by HO2. The increased production of OH resulting from the oxidation of NO by HO2promotes the oxidation of the fuel. A simplified reaction scheme can be proposed for the NO-seeded oxidation of methanol: NO+HO2⇒NO2+OH followed by OH+CH3OH⇒H2O+CH2OH and CH3O. The enhanced oxidation of methanol by addition of NO2is also due to additional OH production through: NO2+HO2⇒HONO+O2, NO2+H⇒NO+OH and HONO⇒NO+OH followed by OH+CH3OH⇒CH2OH and CH3O. The further reactions CH2OH+O2⇒CH2O+HO2; CH3O⇒CH2O+H; CH2O+OH⇒HCO; HCO+O2⇒HO2and H+O2⇒HO2complete the sequence whether NO or NO2is added.