Study of ozone concentration from CO2 decomposition in a water cooled coaxial dielectric barrier discharge

Abstract

In this paper, study of ozone concentration from dissociation of CO2 at atmospheric pressure by a 6 l/min water-cooled cylindrical dielectric barrier discharge was reported. The discharge was powered by a high voltage generator (20 kV, 300 W, ~20 kHz) at 25% and 50% burst and pure AC modes. All experiments were done in three different CO2 gas flow rates namely 1.5, 2 and 2.5 l/min. Because of cooling rate of ~3 °C/s, dielectric of fused quartz and grounded mesh electrode were kept at room temperature 298±1 K, during micro plasma discharges. Ozone concentration at different flow rates versus electrical power dissipated in the plasma were presented in burst mode and pure AC mode. The highest ozone concentration of 336 ppm was observed for 1.5 l/min of CO2 flow rate at 12.5 kV, 37.2 mA filamentary pure AC mode discharge whilst the lowest ozone production rate of 13.5 ppm was observed for 2.5 l/min of CO2 flow rate at 10.5 kV, 27.2 mA and 25% duty cycle in burst mode discharge. The activated species formed inside the CO2 plasma were identified by optical emission spectroscopy. Effect of water cooling on ozone concentration in a cylindrical micro plasma discharge was studied.