摘要:

AbstractThe oxidative pyrolysis of methylene chloride, chloroform, and carbon tetrachloride has been investigated using a micro‐bore, fused silica, tubular flow reactor operating under laminar flow conditions coupled to in‐line GC‐MS detection. Data were obtained over the temperature range 573–1273 K for the following conditions: chlorocarbon/oxygen equivalence ratios of 3.0, chlorocarbon concentrations of 2.7 ± 0.1 × 10−5mols/L, gas‐phase residence times of 2.0 s, and reactor pressures of 1.15 ± 0.05 atm. The parent stability (defined by the temperature required for 99% destruction) was evaluated as:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm CH}_2 {\rm Cl}_2 :1028{\rm\, K, CHCl}_3 :873{\rm\, K,}\,{\rm CCl}_{\rm 4} :1153{\rm\, K} $$\end{document}Chemically activated recombination of chlorinated C1radicals are proposed as important pathways to chlorinated ethane and olefin products. The most significant finding from analysis of product distributions containing ≥2 carbon atoms was the observation of ca. 1 mol% yields of higher‐molecular‐weight perchlorinated aromatic species from the decomposition of chloroform and carbon tetrachloride. Implications with respect to the controlled high‐temperature incineration of these chlorinated methanes

ISSN:0538-8066    

DOI:10.1002/kin.550231202

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractReactions of the hydroxyl radical, OH, with several organic species of interest in combustion chemistry have been studied near 1200 K and 1 atm in shock tube experiments in which UV absorption was used to monitor the OH concentration. Rate coefficients were measured for the reactions of OH with 2,3‐dimethylbutane, isooctane, neooctane, ethylene, propylene, acetylene, formaldehyde, methanol, and ethanol. The values were found to be (in units of 1012cm3/mol‐s): 21, 22, 18, 2.6, 9.6, 0.28, 12, 5.2, and 5.3. These measured values are compared with previous experimental results and, where appropriate, transition‐state theory calcula

ISSN:0538-8066    

DOI:10.1002/kin.550231203

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractRate constants for the reactions of OH radicals and Cl atoms with CH3ONO, C2H5ONO,n‐C3H7ONO,n‐C4H9ONO, andn‐C5H11ONO have been determined at 298 ± 2 K and a total pressure of approximately 1 atm. The OH rate data were obtained using both the absolute rate technique of pulse radiolysis combined with kinetic spectroscopy and a relative rate method involving simultaneous measurement of the loss of the nitrite and the reference compound. The Cl rate constants were measured using the relative rate method. Values of the rate constants in units of 10−13cm3molecule−1s−1are:TextRelative ClRelative OHAbsolute OHCH3ONO94.4 ± 7.43.0 ± 1.02.6 ± 0.5C2H5ONO295 ± 137.0 ± 1.57.0 −1.1n‐C3H7ONO646 ± 5811.0 ± 1.512.0 ± 0.5n‐C4H9ONO1370 ± 5822.7 ± 0.827.2 ± 6.0n‐C5H11ONO2464 ± 44437.4 ± 5.042.5 ± 8.0When compared to rate data for the corresponding alkanes the results show that the ‐ONO group decreases the rate constant for H atom abstraction by the OH radical from groups bonded to the ‐ONO group and also decreases that for groups in the β position. Similar results were found for the reaction of Cl atoms with these compounds. The results are

ISSN:0538-8066    

DOI:10.1002/kin.550231204

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis article describes a general kinetic formalism for treating the details of heterogeneous reactions at a gas‐solid interface. We develop a nomenclature for treating reactions between the gas phase and surface species residing on any number of surface site types and bulk‐phase species residing in bulk‐phase mixtures or in pure bulk phases. The rate of progress of surface reactions follows the law of mass‐action. We discuss the relationship between macroscopic conservation laws for mass and energy and the microscopic surface reaction rates as they might appear in boundary conditions for a chemically reacting flow. The formalism developed has been implemented in a general package of Fortran computer codes for the evaluation of complex surface‐reaction kinetics called Surfac

ISSN:0538-8066    

DOI:10.1002/kin.550231205

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe thermal reaction of HNCO has been studied in a static cell at temperatures between 873 and 1220 K and a constant pressure of 800 torr under highly diluted conditions. The reaction was measurable above 1000 K by FTIR spectrometry. The products detected include CO, CO2, HCN, NH3, and the unreacted HNCO. In this moderate temperature regime, the rates of product formation and HNCO decay cannot be accounted for by a previously established high‐temperature mechanism, assuming HNCO → NH + CO (1) as the initiation process. Instead, a new bimolecular reaction, 2HNCO → CO2+ HNCNH (2), has been invoked to interpret the disappearance of HNCO as well as the formation of various products, most importantly CO2.The concentration profiles of all measured species can be quantitatively modeled, throughout the temperature range analyzed, by varyingk2using a modified mechanism. The kinetically modeled values ofk2can be effectively represented by\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{\rm 2} = 10^{10.84 \pm 0.07} {\rm \,exp}(- 21,240 \pm 1,960/{\rm T}){\rm\, cm}^3 /{\rm mol\, s}{\rm .} $$\end{document}This result agrees closely with that computed with the conventional transition‐state theory using the TST parameters predicted by the BAC‐MP4 method:\documentclass{article}\pagestyle{empty}\begin{document}$$ k_2 ({\rm BAC} - {\rm MP}4) = 10^{11.13} {\rm \,exp(- 21,600/T) cm}^{\rm 3} /{\rm mol s}{\rm .} $$\end{document}The bimolecular reaction takes place via a stable 4‐membered ring intermediate which is isoelectronic with di

ISSN:0538-8066    

DOI:10.1002/kin.550231206

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550231201

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY