Mechanistic Models of Soot Formation

Abstract : A detailed chemical kinetic mechanism for the pyrolysis of toluene and the formation of polyaromatic hydrocarbons has been developed. This chemical kinetic model is consistent with shock tube data with mass spectral identification of intermediate species. This kinetic analysis provides a better understanding of how aromatic rings decompose and how polyaromatic species grow. In addition, a previously developed soot formation code, based on a sectional aerosol model for predicting soot inception, growth, and oxidation in a premixed flame has been fully integrated into an opposed-jet, diffusion flame code. The new code includes effects due to radiation from both gaseous species and particulates as well as scavenging of species by soot. The code treats particle transport including thermophoresis. Predictions from a low strain rate, lightly- sooting, methane-fueled, opposed-jet, diffusion flame are included in this report. Perturbation studies demonstrate the importance of fully integrating soot production, radiation, and scavenging in order to reasonably predict bulk parameters such as temperature, as well as species concentrations, sooting levels and radiation loads. Soot formation modeling, Chemical kinetics of toluene pyrolysis, Formation mechanisms and thermodynamics of polyaromatic hydrocarbons, Soot formation in opposed jet flames