Soot formation during the pyrolysis and oxidation of acetylene and ethylene in shock waves

Abstract

Experimental and computational studies of soot formation during the pyrolysis and oxidative pyrolysis of hydrocarbons with multiple bonds have been performed on ethylene and acetylene as examples. The experiments have been carried out behind reflected shock waves over the temperature range from 1700 to 2800 K at a pressure of 3 to 5 bar. The process of soot formation was recorded using the absorption-emission method, which enables one to simultaneously measure the mass of soot particles per unit volume and their temperature. The experimental data are interpreted within a new kinetic mechanism that takes into account the nucleation of soot particles from both polyaromatic hydrocarbon fragments and unsaturated aliphatic hydrocarbons. The proposed kinetic model of soot formation closely reproduces the time dependence of the soot yield and the temperature of soot particles measured in the present work, as well as the concentrations of several key components formed in the early stages of pyrolysis and oxidation of acetylene and ethylene, reported in a number of works by other authors.