Kinetic Modeling of Heptane Combustion and PAH Formation

A kinetic model for high-temperature oxidation and pyrolysis of heptane has been developed. This model is based on new results for heptane decomposition, decomposition and isomerization of heptyl radicals, and decomposition of olefins and olefinic radicals. It is combined with kinetic data from Grimech-3.0 model on the reactions of C1-C2 species. The subset on C3-C4 chemistry is based on the works of Marinov et al. (1998) and Laskin et al. (2000). The database for PAH formation is based on the results from kinetic models on heptane suitably modified from various soot formation models. The model was validated against experimental data on burning velocity, ignition delays, and OH time history during heptane ignition behind shock wave. The reactions determining burning velocity were established through sensitivity analysis. The main reactions determining burning velocity of heptane are similar to the reactions determining burning velocity of CI-C4 hydrocarbons. The influence of product distribution of heptyl radical decomposition on PAH production was analyzed.