In this dissertation a comparative study is presented of four different detailed kinetics models involving the main chemical species responsible for the soot formation and oxidation, i.e., the molecular oxygen, the hydroxyl, the acetylene, the propargyl, the benzene and the pyrene. To this purpose is considered the combustion of ethylene/air and metane/air. To analyze the kinetic models are used a perfect stirred reactor (PSR) and a partial stirred reactor (PaSR). In the case of a perfect stirred reactor a systematic study of the influence of the residence time and of the equivalence ratio on these chemical species is presented. Are discussed the important discrepancies obtained for acetylene, propargyl, benzene, phenyl and pyrene, between the kinetic models analyzed. The oxidizing species exhibit minor discrepancies only. In the case of the partially mixed reactor, the ratio between the residence time and the mixing time is the analysis parameter. Overall, the results obtained allow to evaluate the behavior of the kinetic mechanisms in situations representative of combustion in turbulent flows.