NOx remediation in oxygen rich exhaust gas using atmospheric pressure non-thermal plasma generated by a pulsed nanosecond dielectric barrier discharge
Résumé
It is clearly seen that the application of non-thermal plasmas (NTP) to remove NOx from gas mixture containing a large amount of oxygen (O2) is dominated by NO to NO2 oxidation. Experiments has been conducted using a NTP generated by a nanosecond pulsed dielectric barrier discharge (DBD) in synthetic exhaust gas, prepared from N2, O2, NO, H2O, and C3H6, over a large range of gas temperature (20°C-300°C). Results show that the NOx removal rate significantly increased with increasing specific energy deposition. For example, at a temperature of 100°C and an energy deposition of 27 J/l, 92% of the NO molecules have been removed. The W-values for NO is dramatically reduced to values scaling from ≡ 15 eV at 27 J/l down to ≡ 4 eV at 7 J/l. NOx removal efficiency around 43% was obtained at a temperature of 260°C and a space velocity of 60 000 h-1 for a specific input energy of 27 J/l. W-values for NOx were less than ≡ 30 eV. Such treatments in exhaust gas with and without the presence of water vapor induced reactions leading to the production of a large variety of by-products such acetaldehyde, propylene oxide, formic acid, methyl nitrate, and nitromethane.