Investigation of ozone generation using dielectric barrier discharges at 50 Hz, 2.6 kHz and 20 kHz

Experiments were conducted to investigate ozone generation (DBD) at different frequencies. A cylindrical DBD ozone generator with a discharge gap of 0.3 mm has been developed. 50 Hz AC power was used to provide power density of 44.2 W/m3. 2.6 kHz and 20 kHz AC energisation frequencies were employed to provide power densities of 2.37 kW/m2 and 19.08 kW/m2 respectively. Discharge current, optical emission signals and discharge power were obtained under three frequencies. Ozone concentration and production efficiency at different feed gas flow rates were measured and calculated. It was found that discharge mode was different for positive and negative half-cycle of the applied voltage. Results show that ozone production efficiency rises with an increase in the ozone concentration at 50 Hz, however this efficiency drops with an increase in the ozone concentration at 2.6 kHz and 20 kHz. For the same ozone concentration level, 2.6 kHz is more efficient than 20 kHz. The highest ozone production efficiency achieved in this work is 191.5 g/kWh at 50 Hz and the highest ozone concentration is 271 g/Nm3 at 2.6 kHz