Chemistry of high temperature combustion of alkanes up to octane

TLDR: In this article, a detailed mechanism for rate-controlling combustion of alkanes and alkenes is proposed, which can be used to explain non-Zeldovich NO formation or formation of soot precursors.

Abstract: Alkanes are initially attacked by H, O, and OH radicals generated in the oxyhydrogen reaction. The alkyl radical formed in this way decomposes to smaller alkyl radicals by fast thermal elimination of alkenes. Only the relatively slow thermal decomposition of the smallest alkyl radicals, CH3 and C2H5, competes with recombination and with oxidation reactions by O atoms and O2. This part of the mechanism is rate-controlling in the combustion of alkanes (and alkenes) and must be described by a detailed mechanism consiting of elementary reactions. Alkyl radical decomposition and the reactions leading to C1-and C2-fragments are too fast to be rate-limiting and can therefore be described by simplified reaction schemes disregarding alkyl isomeric structures. Simulations of flames of higher alkanes (up to octane) using these simplifying assumptions show agreement with the experimental material available. The mechanism derived by these considerations can then be used to explain of phenomena (like non-Zeldovich NO formation or formation of soot precursors), which can be interpreted from a detailed knowledge of the C1/C2-chemistry.