Kinetic features of non-thermal plasma conversion of propane-air mixture at high pressure

The paper presents the results of modeling the conversion of a lean non-combustible propane-air mixture with initiation by a high-frequency corona discharge at a pressure of 5 bar and an initial temperature of 300 K for different equivalence ratios. The discharge creates non-thermal plasma in filament channels. Experiments on the development of such a discharge in air for different conditions were carried out. At pressures of 1 and 2 bar, the discharge has a complex morphology with branching of discharge filaments. At pressures above 3 bar, the glow region has the shape of a straight spoke. The paper presents a kinetic analysis of the conversion. The key component for propane decomposition is the O atom produced in the discharge as a result of O₂ dissociation by direct electron impact and excited N₂ molecules. In the afterglow, after completion of discharge, the source of the O atom is the reactions of ozone decomposition with N₂ and O₂. For the formation of NO, it is necessary to take into account the production of N atoms in the excited and ground states. Intermediate oxidized hydrocarbons play a major role in increasing the concentrations of C₃H₆, C₂H₄, and CO over time. The decomposition of O₃ occurs to a greater extent in a cycle involving NO₃. The heating of the discharge-activated zone did not exceed 600 K. The composition of the conversion products obtained as a result of modeling was compared with known experimental literature data.