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首页> 外文学位 >A SINGLE PULSE SHOCK TUBE STUDY OF THE CHEMICAL MECHANISMS OF SOOT FORMATION FROM BENZENE PYROLYSIS.
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A SINGLE PULSE SHOCK TUBE STUDY OF THE CHEMICAL MECHANISMS OF SOOT FORMATION FROM BENZENE PYROLYSIS.

机译：苯热解形成烟灰化学机理的单脉冲冲击管研究。

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摘要

The thermal decomposition of vapor phase benzene has been studied using a single pulse shock tube. The reaction was studied over a temperature range of 1300 - 2300K, with initial benzene concentrations varying from (0.4 - 1.25) x 10('-6) mole cm('-3) and reaction times of 0.1 to 3.0 msec. Stable products formed were analyzed by gas chromatography, mass spectrometry and, in the case of solid products, by gravimetric determination.;Collection of solid products was achieved using a removable liner to the shock tube that could be weighed before and after the reaction. Recovery of solid and gas phase species was found to be 85-95% of the original reactant mass over the temperature range studied. Soot yields were observed to increase with increasing temperature from zero at 1300K to a plateau value of 0.8 which was maintained up to a reaction temperature of 2700K. Soot yields were shown to be substantial even when the reaction was immediately cooled. Subsequent experiments in which the reaction dwell time was varied have led to an estimated activation energy of the limiting soot formation reactions of ca 25 kJ/mole and to a frequency factor of 10('9.9) mole('-1) cm('3) sec('-1). Results of experiments in which the initial benzene concentration was varied are tenuous but suggest that over at least part of the concentration range studied, decreasing benzene concentration leads to higher yields of soot.;Benzene disappearance has been demonstrated to be second order with respect to benzene concentration and the reaction rate constant is best described by K(,II) = 4.0 x 10('14) exp(-19250/T) mole('-1) cm('3) sec('-1). Product analyses have shown that the principle products formed are acetylene and styrene. Smaller concentrations of diacetylene, methane, vinylacetylene, ethylene, and toluene were observed. Quantitative measurements of the two major products have indicated that the acetylene yields are well described by thermodynamic equilibrium calculations and are present under virtually all conditions, whereas the styrene is observed in a narrow temperature range. ('13)C labeled benzene has been used to deduce the means by which selected products are formed. This technique has demonstrated that acetylene is principally formed directly from ring scission with the remainder being formed by C(,1) fragment recombination, the C(,4) compounds observed are formed primarily via acetylene recombination and styrene is formed mainly by an acetylenic reaction with the benzene ring.
机译：已经使用单脉冲激波管研究了气相苯的热分解。在1300-2300K的温度范围内对反应进行了研究，初始苯浓度为（0.4-1.25）x 10（'-6）摩尔厘米（'-3），反应时间为0.1至3.0毫秒。通过气相色谱法，质谱法分析形成的稳定产物，对于固体产物，通过重量分析法进行分析。使用可移动的衬里收集震荡管中的固体产物，该衬里可以在反应之前和之后称重。在所研究的温度范围内，发现固相和气相物种的回收率为原始反应物质量的85-95％。观察到烟ot产率随温度的增加而增加，从1300K的零升高到平稳值0.8，该稳定值一直保持到2700K的反应温度。即使立即将反应冷却，也表明烟灰收率很高。随后的反应停留时间发生变化的实验导致极限烟灰形成反应的估计活化能约为25 kJ / mol，频率因子为10（'9.9）mole（'-1）cm（'3 ）sec（'-1）。苯初始浓度变化的实验结果很微弱，但表明在所研究的至少一部分浓度范围内，降低苯浓度可导致更高的烟ot收率。苯的消失已证明是苯的第二级浓度和反应速率常数最好用K（，II）= 4.0 x 10（'14）exp（-19250 / T）摩尔（'-1）cm（'3）sec（'-1）来描述。产物分析表明，形成的主要产物是乙炔和苯乙烯。观察到较低浓度的二乙炔，甲烷，乙烯基乙炔，乙烯和甲苯。两种主要产物的定量测量表明，乙炔收率可以通过热力学平衡计算得到很好的描述，并且实际上存在于所有条件下，而苯乙烯则在较窄的温​​度范围内观察到。 （'13）C标记的苯已用于推导形成选定产物的方法。该技术已证明乙炔主要由环断裂直接形成，其余部分由C（，1）片段重组形成，观察到的C（，4）化合物主要通过乙炔重组形成，而苯乙烯主要由乙炔反应形成与苯环。

著录项

  • 作者

    VAUGHN, STEPHEN NEIL.;

  • 作者单位

    Kansas State University.;

  • 授予单位 Kansas State University.;
  • 学科 Engineering Chemical.
  • 学位 Ph.D.
  • 年度 1980
  • 页码 206 p.
  • 总页数 206
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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