Gas cleaning with semi-wet type plasma reactor

Abstract

An experimental study on the removal of NH/sub 3/, NO, and NO/sub x/ in concentrations of 10-40 ppm in air has been carried out using plasma chemical reaction in a streamer corona discharge. The results of the performance of dry-type and semi-wet-type reactors are compared. The effect of different types of applied voltages such as rectangular pulse, 60 Hz sinusoidal, and 18 kHz alternating voltages is investigated. During NO removal, O/sub 3/ and NO/sub 2/ are produced. NO/sub 2/ can, partially, be removed with higher power input into the discharge. Another undesirable pollutant, namely N/sub 2/O, is also produced, especially in the case of dry reactors having long residence time ( approximately 2.4 s). N/sub 2/O production decreases, essentially, to zero at 0.6 s residence time when using a semiwet reactor. In general, higher removal efficiency has been obtained with pulse voltage in a wet reactor. NH/sub 3/ in air appears to produce ozone and ammonium nitrate in a discharge. The performance of semiwet reactors with regard to the removal of submicron dust particles has also been investigated and very high removal efficiency ( approximately 93% at 0.6 s residence time) has been obtained.<>