Destruction of volatile organic compounds in air by means of DC and pulsed high pressure glow discharges

摘要

Summary form only given. High-pressure, direct current glow discharges have been studied with respect to their use as nonthermal plasma reactors, in particular with respect to volatile organic compound (VOC) decontamination of air. The experimental setup consists of a gas handling system with flow control, a reaction chamber containing a 200 Torr to 400 Torr plasma, a buffer chamber and a gas chromatograph as diagnostic system. In experiments a premixed gas consisting of air with 300 ppm benzene was flown through a direct current plasma filament contained in a 1 mm wide and 11 mm long dielectric slit. The length of the plasma in the flow direction was about 0.8 mm. A destruction efficiency of more then 80% has been achieved with the DC method, at a residence time of the flowing gas in the plasma column of 0.2 ms. The destruction energy efficiency was measured as approximately 10/sup 15/ VOC molecules/Joule, which is lower by about a factor of six than that obtained with dielectric barrier discharges. However, by using pulsed electric fields of 10 ns duration, instead of DC voltage, we were able to increase the destruction efficiency for benzene by almost one order of magnitude.