Investigation of pulsed micro-discharges and ozone production by dielectric barrier discharges

In this work, pulsed micro-discharges produced by dielectric barrier discharges (DBDs) with a sub-millimeter gap were electrically-characterized under ac voltage at 100 Hz and at 5 kHz. Ozone production was investigated for different discharge gap lengths and pressures. The aim of the work was to understand the statistics of filamentary current pulses and their relationship to the reduced electric field and the ozone production efficiency. A transient sinusoidal voltage of 200 cycles was employed to reduce the heating effects in the ozone-synthesis process. It was shown that the amplitude of the filamentary current pulses measured over 200 voltage cycles conformed to a Gaussian distribution. The mean filamentary current and ozone production efficiency measured at 100 Hz and at 5 kHz were almost the same. The ozone production efficiency was found to increase with increasing pressure from 1 bar to 2 bar, and the gap length from 0.2 mm to 0.5 mm. The maximum ozone production efficiency achieved in the work was 217 g/kWh, with a gap length of 0.5 mm, 2.0 bar absolute pressure, and an applied voltage of 5.5 kV at 5 kHz.