Oxidation chemistry of propene in the autoignition region: arrhenius parameters for the allyl + O2 reaction pathways and kinetic data for initiation reactions
- 1 January 1992
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Faraday Transactions
- Vol. 88 (18) , 2621-2629
- https://doi.org/10.1039/ft9928802621
Abstract
The oxidation of propene has been studied at a total pressure of 60 Torr between 400 and 520 °C, and a detailed product analysis made in the initial stages of reaction over a wide range of mixture composition. Mechanisms for the formation of the products are discussed. The initial rates of formation of hexa -1,5 -diene (HDE) and carbon monoxide are used to obtain A8= 109.66±0.35 dm3 mol–1 s–1 and E8= 78.6 ± 4.5 kJ mol–1, the former giving [allyl] from the known value of k1[graphic omitted] + [graphic omitted] → CH2 CHCH2CH2CH CH2(1)[graphic omitted] + O2→ CO + products (8) Arrhenius parameters are also given for alternative pathways of the allyl + O2 reaction. All involve high energy barriers. From measurements of the accelerating effect of small amounts of the additives CH3CHO, HCHO, HDE and propene oxide, rate constants at 480 °C are obtained (for the first three) for the initiation reaction (21).RH + O2→ R + HO2(21) Very few independent data for this type of reaction are available. The accelerating effect of propene oxide is ascribed to an exothermic isomerisation product which is not thermally stabilised at 60 Torr and undergoes homolysis to radical fragments. HDE is shown to have a spectacular accelerating effect on propene oxidation and value of k21n/k10= 1050 ± 200 at 480 °C is obtained.C3H6+ O2→ [graphic omitted] + HO2(10) HDE + O2→ [graphic omitted]CH2CH CH2+ HO2(21h)Keywords
This publication has 0 references indexed in Scilit: