Experimental Study On DC Corona Radical Shower For The Removal Of Volatile Organic Compounds

The control of volatile organic compounds (VOCs) is receiving more and more attention. DC corona radical shower technique is regarded as a promising technique in VOCs control.Experimental study on VOCs treatment by DC corona radical shower was investigated in this paper. A set of equipment for experiment has been set up. On this equipment, the experiment was carried out to study different parameters' effect on the decomposition of benzene and toluene. The reaction mechanism and the experimental apparatus were discussed in this paper, too. The results shows:VOCs decomposing efficiency increased with humidity increasing. When it reached the maximum in the range of RH=46% to RH=64%, removal efficiency would be decreased with humidity increasing. The decomposing efficiency is influenced by nozzle electrode gas flux; it could be seen that the decomposing efficiency went up with the increase of voltage; the residence time longer, the decomposing efficiency was higher; decreasing the concentration of VOCs would improve the decomposing efficiency. The results showed that Fenton-type reaction increased toluene's decomposing efficiency remarkably. Toluene decomposing efficiency enhanced 10.9%, 24.3% and 15.7% in the presence of Fenton-type reagent Fe(II), Mn(II) and Co(II) in turn at the concentration of 0.05mol/l. It was found this is a good method to improve the removal efficiency of toluene.The main decomposition products of VOCs were CO₂ and H₂O. There were O₃ and NO₂ that were produced in the process of discharging. The concentration of NO2 was low. O3 plays an important role in VOCs treatment and its concentration is low enough before the flue gas was let out of the reactor.A dynamics model was proposed to describe the relation of the removal efficiency with energy density, and initial concentration. The decomposition rate constants of toluene and benzene were 0.2666, 0.1398m³ ·J^-1 respectively. It could be seen from the results that toluene was easier than benzene to be decomposed.Decomposition was commonly beginning with side chain and so the decomposition efficiency of toluene was higher than benzene. VOCs decomposition mechanism can be considered as following.RH + O·→R·+OH·RH + O·→R₁·+R₂O·RH + OH·→R·+H₂O...