Heterogeneous and platinum-initiated homogeneous combustion of nitrogen-containing heterocyclic compounds in the argon and water vapor media at elevated pressure

Abstract

The paper presents the results on the oxidation of pyrrole and pyridine in the argon and water vapor media at high pressure and uniform heating of the tubular stainless steel reactor to 823 K. Experiments were carried out with lean and stoichiometric mixtures (fuel equivalence ratio φ = 0.78–1.01) at their dilution level x D = 36–65% mol. Based on the time dependences of the reaction mixture temperature, it is revealed that oxidation proceeds via the mechanisms of homogeneous and heterogeneous reactions. It was found that the oxidation rate of pyrrole depends on the amount of corrosion products accumulated on the reactor wall. It is shown that a Pt-Rh/Pt thermocouple inserted into the center of the reaction volume intensifies pyridine oxidation in the near-surface region. The difference in the oxidation mechanisms of pyrrole and pyridine is explained by the structure of their molecules.