title: Experimental and modeling investigation of the low-temperature oxidation ofn-heptane.
abstract: The low-temperature oxidation ofn-heptane, one of the reference species for the octane rating of gasoline, was investigated using a jet-stirred reactor and two methods of analysis: gas chromatography and synchrotron vacuum ultra-violet photo-ionization mass spectrometry (SVUV-PIMS) with direct sampling through a molecular jet. The second method allowed the identification of products, such as molecules with hydroperoxy functions, which are not stable enough to be detected using gas chromatography. Mole fractions of the reactants and reaction products were measured as a function of temperature (500-1100K), at a residence time of 2s, at a pressure of 800 torr (1.06 bar) and at stoichiometric conditions. The fuel was diluted in an inert gas (fuel inlet mole fraction of 0.005). Attention was paid to the formation of reaction products involved in the low temperature oxidation ofn-heptane, such as olefins, cyclic ethers, aldehydes, ketones, species with two carbonyl groups (diones) and ketohydroperoxides. Diones and ketohydroperoxides are important intermediates in the low temperature oxidation of n-alkanes but their formation have rarely been reported. Significant amounts of organic acids (acetic and propanoic acids) were also observed at low temperature. The comparison of experimental data and profiles computed using an automatically generated detailed kinetic model is overall satisfactory. A route for the formation of acetic and propanoic acids was proposed. Quantum calculations were performed to refine the consumption routes of ketohydroperoxides towards diones.
authors.affiliation: Université de Lorraine, Laboratoire Réactions et Génie des Procédés, UPR 3349, Nancy, F-54000, France ; CNRS, Laboratoire Réactions et Génie des Procédés, UPR 3349, Nancy, F-54000, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Herbinet
authors.forename: Benoit
authors.initials: B
authors.lastname: Husson
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Serinyel
authors.forename: Maximilien
authors.initials: M
authors.lastname: Cord
authors.forename: Valérie
authors.initials: V
authors.lastname: Warth
authors.forename: René
authors.initials: R
authors.lastname: Fournet
authors.forename: Pierre-Alexandre
authors.initials: PA
authors.lastname: Glaude
authors.forename: Baptiste
authors.initials: B
authors.lastname: Sirjean
authors.forename: Frédérique
authors.initials: F
authors.lastname: Battin-Leclerc
authors.forename: Zhandong
authors.initials: Z
authors.lastname: Wang
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Xie
authors.forename: Zhanjun
authors.initials: Z
authors.lastname: Cheng
authors.forename: Fei
authors.initials: F
authors.lastname: Qi
keywords: jet-stirred reactor; ketohydroperoxide; low-temperature oxidation; n-heptane; organic acids