Simultaneous production of ketohydroperoxides from low temperature oxidation of a gasoline primary reference fuel mixture

Ketohydroperoxides (KHPs) are oxygenated hydrocarbons that include carbonyl and peroxide functional groups. The decomposition pathways of KHPs chain branching in low temperature chemistry alkanes biofuels, which makes critical intermediates ignition processes advanced combustion engines. In this work, KHP formation was investigated the oxidation a primary reference fuel (PRF 70), binary mixture 30 vol% n-heptane 70 iso-octane to represent octane number gasoline surrogate. Species were detected measured jet-stirred reactor (JSR), coupled with time-of-flight molecular beam mass spectrometer using synchrotron vacuum-ultraviolet radiation as photon ionization source (SVUV-PI-TOF-MBMS) provides in-situ measurement unstable KHPs. Simultaneous production from higher reactivity lower at similar temperatures observed. Kinetic modeling used study across wide range examine chemistry. Specifically, signals vs. profiles experiments mole fraction simulations, compared indicate most possible saturated isomers. Possible for olefinic di-olefinic discussed. This work reports simultaneous two molecules surrogate mixture, discusses important reaction oxidation, explains n-heptane/iso-octane mixtures, i.e., less reactive is initiated by OH radicals produced high oxidation.