Kinetic study for the production mechanism of halo-dibenzo-p-dioxin

卤代二苯并对二恶英生成机理的动力学研究

• 批准号: 13650827
• 负责人: FUJII Nobuyuki
• 金额: $ 2.3万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650827/
• 关键词: dibenzo-p-dioxin; production; shock-tube; phenoxy radical; gas chromatography; mechanism; high-temperature; combustion; ダイオキシン骨格; 生成反応機構; シクロペンタジエニルラジカル; 脱水素付加反応; 衝撃波管実験; 原子共鳴分光法; メトキシベンゼン

In order to confirm that the dibenzo-p-dioxin production channel in combustion is 2C_6H_5O→C_6H_4O_2C_6H_4+2H, high temperature reactions of phenoxy radicals (C_6H_5O) were investigated over the temperature range 1250 - 1700 K using shock-tube techniques. Methoxybenzene (C_6H_5OCH_3) and trifluromethoxybenzene (C_6H_5OCF_3) were used as sources of C_6H_5O radicals. By comparing the experimental results with those by computer simulations, high temperature reactions of C_6H_5O radicals including the dibenzo-p-dioxin production channel were discussed. Reaction products of C_6H_5O decomposition were also analyzed with gas chromatography by sampling the final products behind the reflected shock of C_6H_5OCH_3 and C_6H_5OCF_3 diluted with Ar mixtures. We found that not only the linear hydrocarbons but also aromatic compounds such as phenol were produced behind the shock. However the dibenzo-p-dioxin was not detected as the final products behind the shockwaves of C_6H_5OCH_3 and C_6H_5OCF_3 diluted with Ar mixtures. To simulate the temperature dependence of the yield of dibenzo-p-dioxin production, kinetic model for dibenzo-p-dioxin formation was proposed and compared with the experimental observations.

为了证实燃烧过程中二苯并对二恶英的生成途径是2C_6H_5O→C_6H_4O_2C_6H_4+2H，利用激波管技术研究了苯氧基自由基（C_6H_5O）在1250 - 1700 K温度范围内的高温反应。以三氟甲氧基苯(C_6H_5OCF_3)为C_6H_5O自由基源，通过与计算机模拟结果的比较，讨论了C_6H_5O自由基的高温反应，包括C_6H_5O分解的反应产物。通过对 C_6H_5OCH_3 反射冲击后的最终产物进行气相色谱分析我们发现，在C_6H_5OCH_3和C_6H_5OCF_3稀释后的冲击波后，不仅产生了直链烃，而且还产生了苯酚等芳香族化合物。为了模拟二苯并-对-二恶英产量的温度依赖性，提出了二苯并-对-二恶英形成的动力学模型，并与实验观察结果进行了比较。