Physico-chemical modeling of positive corona discharge in carbon dioxide

Positive wire-to-cylinder corona discharge in pure CO₂ has been simulated using a model that includes elementary plasma processes (ionization, electron attachment and detachment, ion recombination, etc.) and chemical reactions between neutral species. The plasma chemistry model is included in the continuity equations of species, which are coupled with Poissons equation for the electric field and the energy conservation equation for the gas temperature. The experimental values of voltage and current are used as input data into the numerical simulation, and the spatial distributions of electrons, ions, atoms and molecules are then predicted for different gas flow rates. The average concentrations of ozone and carbon monoxide inside the discharge reactor have been experimentally determined by means of ultraviolet and FTIR spectrometry, and their values are compared with the results of the numerical simulation.