Ozone generation in dry air using pulsed discharges with and without a solid dielectric layer

Abstract

Energy efficient generation of ozone is very important because ozone is being used increasingly in a wide range of industrial applications. Ozonizers usually use dielectric barrier discharges and employ alternating current (ac) with consequent heat generation, which necessitates cooling. In the present study, very short duration pulsed voltage is employed resulting in reduced heating of the gas and discharge reactor. A comparison of ozone generation in dry air using a coaxial concentric electrode system with and without a solid dielectric layer is reported. Two types of dielectric layers were employed, ceramic and polyvinylchloride (PVC). The effects of peak pulsed voltage (12.5 to 62 kV), reactor length (0.1 to 1 m), pulse repetition rate (25 to 400 pulses per second, pps), gas flow rate (1.5 to 3.0 llmin) and variation of the pitch length of the spiral wire forming the central electrode (5 to 10 mm) on the concentration and production yield of ozone (glkwh) are reported. A comparison is made between the performance of discharge reactors with (ceramic reactor Type IIC and PVC reactor Type IIP) and without (reactor Type I) a dielectric layer, using the same electrode gap separation (15 mm) and reactor lengths (0.157 and 1 m). High production yields of ozone in dry air of -122, 52 and 60 glkwh were obtained when using, respectively ceramic, PVC, and no dielectric layer, for a fixed pulse rate of 100 pps, 1.5 llmin flow rate and for a relatively short length of the reactor of 157 mm.

Collection of submicron particles by an electrostatic precipitator using a dielectric barrier discharge

“…Until recently, DBD has been mainly used as an effective ozone generator (Eliasson, Hirth, & Kogelschatz, 1987;Gutierrez-Tapia, 1998;Samaranayake et al, 2000Samaranayake et al, , 2001. Now, however, researchers are investigating the feasibility of DBD application for a wide range of fields.…”

A numerical study of species and electric field distributions in pulsed DBD in oxygen for ozone generation

“…Chalmers [2] obtained ozone yield of around 300 g/kWh in oxygen wire-cylinder pulsed DBD. Akiyama [1,3,4] carried out a systematical experiment to investigate the effect of various parameters on ozone generation in wire (spiral wire)-cylinder pulsed DBD fed with oxygen or dry air. The highest ozone yields of about 100 g/ kWh in dry air and 202 g/kWh in oxygen were achieved.…”

Enhancement of Energy Yield for Ozone Production via Packed-Bed Reactors

“…For most plasma-type ozone generators, the maximum ozone concentration and energy yield cannot be attained at the same time in the same operation condition (Samaranayake et al, 2001). Therefore, a choice must be made between ozone concentration and energy yield in most cases.…”