Experimental and modeling study of oxidation and autoignition of butane at high pressure

Oxidation and autoignition of stoichiometric, lean (ϕ = 0.8), and rich (ϕ = 1.2) butane-“air” mixtures are studied in a rapid compression machine between 700–900 K and 9–11 bar. Information is obtained concerning cool flames and ignition delays. Product profiles for selected major and minor species are measured during a two-stage ignition process. The presence of C 4 heterocycles may be connected to isomerization and decomposition of butylperoxy radicals. The experimental results are compared with numerical predictions of an homogeneous adiabatic model based on the Pitz-Westbrook comprehensive chemical mechanism of 1990. The experimental and predicted delays are in the same order of magnitude. A relatively good agreement is found for the major species profiles. Improvement of the mechanism is needed to account for the minor products. The different paths of OH formation are discussed.