Young Jin Hyun

Removal of NO and SO2 by Pulsed Corona Discharge Process

Overall examination was made on the removal of NO and SO2, by pulsed corona discharge process. The mechanism for the removal of NO was found to largely depend on the gas composition. In the absence of oxygen, most of the NO removed was reduced to N2; on the other hand, oxidation of NO to NO2 was dominant in the presence of oxygen even when the content was low. Water vapor was an important ingredient for the oxidation of NO2, to nitric acid rather than that of NO to NO2. The removal of NO only slightly increased with the concentration of ammonia while the effect of ammonia on the removal of SO2 was very significant. The energy density (power delivered/feed gas flow rate) can be a measure for the degree of removal of NO. Regardless of the applied voltage and the flow rate of the feed gas stream, the amount of NO removed was identical at the same energy density. The production of N2O increased with the pulse repetition rate, and the presence of NH3 and SO2 enhanced it. Byproducts generated from propene used as additive were identified and analyzed. The main byproducts other than carbon oxides were found to be ethane and formaldehyde, but their concentrations were negligibly small.

Determination of decomposition rate constants of volatile organic compounds and nitric oxide in a pulsed corona discharge reactor

The decomposition of toluene, propylene and nitric oxide by using a pulsed corona discharge process was investigated. The performance equation of the pulsed corona reactor was derived with the assumption that the decomposition reaction rate is directly proportional to the concentration of the pollutant and the discharge power. From this model equation and the experimental data, the apparent decomposition rate constants of various gaseous organic compounds and nitric oxide were determined. Alkene and substituted alkene were found to have much larger decomposition rate constants than aromatic compounds and substituted alkane, which indicates that the derivatives of aromatics and alkane cannot readily be decomposed in this system. To verify the validity of the model derived, the experimental data in the present study and in the literature were compared with the calculation results using the decomposition rate constants. Despite the different reactor geometry and experimental condition, good agreement between the experimental data and the calculation results was shown.