Correlations between Chemical Structure and Ignition Delay Time of Alkanes (Second Report)

Abstract

The effects of branched structure on the low-temperature oxidation mechanism of hydrocarbon fuel have been investigated by using a steady-state analysis. This analysis shows that both quaternary and tertiary carbon decrease the ratio to chain branching process among the reaction path of alkylperoxy radicals (ROO). A quaternary carbon affects mainly intramolecular hydrogen shift reactions of ROO and cyclic-ether formation reactions of hydroperoxy (QOOH) radical. On the other hand, a tertiary carbon affects HO₂ elimination reaction of ROO and intramolecular hydrogen shift reaction of hydroperoxyalkylperoxy (OOQOOH) radical. These kinetic effects elucidate the correlations between chemical structure and ignition delay time for alkane molecule presented in our previous study.