Étude expérimentale et modélisation des réactions d'oxydation du n-pentane et du cyclopentane

Abstract

The reduction of automotive emissions and the reformulation of gasoline composition require a better understanding of the combustion mechanism, in particular aiming at the determination of the influential reactions which are responsible for the onset of knock in spark ignition engines. We have studied the oxidation mechanism of two hydrocarbons of different research octane number: n-pentane (62) and cyclopentane (100). This work follows a previous study on the oxidation of n-heptane and isooctane. The experimental study was performed at 873 K in a jet-stirred flow reaction vessel. The reaction mechanisms of n-pentane and cyclopentane were analysed on a purely kinetic basis, derived from our experimental results, and were finally modelled by using a programme of simulation of reaction mechanisms. The different behaviour of these two hydrocarbons with respect to autoignition phenomena is mainly dependent on the relative concentration of resonance-stabilized radicals in the reaction medium. Keywords: oxidation reaction, n-pentane, cyclopentane, modelling, autoignition.

The autoignition of cyclopentane and cyclohexane in a shock tube

“…T 2 exp(-5000/T) cm3 .mol -1 .s -1 and k 7' = 2.25x10 8 T 2 exp(-5000/T) cm 3 .mol -1 .s -1 ); with this change the rate constants used here are in agreement with the values measured by the team of Walker[24,25] within a factor around 2. In addition, the decompositions by β-scission involving the breaking of a C-H bond from cyclohexyl radicals to give cyclohexene(8) is taken into account as the reverse of the corresponding additions of H atoms to the double bond.…”

A shock tube study of cyclopentane and cyclohexane ignition at elevated pressures

“…Previous kinetic measurements for cyclopentane have been made in a jet-stirred reactor by Simon et al [12], and in shock tubes by Orme et al [13], and Sirjean et al [6]. Previous kinetic measurements for cyclohexane have been performed in jet-stirred reactors by El Bakali et al [7] and Voisin et al [14], in a static reactor by Klai and Baronnet [15,16], in a rapid compression machine (RCM) by Lemaire et al [17], and in a shock tube by Sirjean et al [6].…”

Review of Oxidation of Gasoline Surrogates and Its Components

“…The autoignition of cyclohexane has been studied using shock tubes [75][76][77], RCMs [26,70,78], JSRs [72,74], plug-flow reactors [79,80], and closed reactors [81][82][83][84]. The ignition characteristics of cyclopentane were studied using shock tubes [75,76,85] and a JSR [86]. The autoignition of cyclopentane and cyclohexane was observed to be more pressure dependent than olefins.…”