1994 Volume 37 Issue 2 Pages 413-419
The soot formation during combustion is described by a theory based on cluster kinetics. Kinetic calculations in which carbon vapors (C1 - C5) and polyacetylenes are assumed to be the collision partners for cluster reactions support the formation by soot via soot clusters at higher temperatures. The prediction of the proposed theory agrees well with both the bell-shaped temperature dependence of soot yield and the rapid soot formation as observed from shock-tube experiments. It is also shown that the small clusters are mainly generated via C2H, and they grow into large clusters by reaction with carbon vapors at moderately high temperatures, while they are decomposed into carbon vapors at very high temperatures. Furthermore, the effects of pressure and heterogeneous nuclei such as condensed PAHs on soot formation are discussed.