NOx remediation in oxygen-rich exhaust gas using atmospheric pressure non-thermal plasma generated by a pulsed nanosecond dielectric barrier discharge

It is clearly seen that the application of non-thermal plasmas (NTP) to remove NO x from gas mixture containing a large amount of oxygen (O 2 ) is dominated by NO to NO 2 oxidation. Experiments have been conducted using a NTP generated by a nanosecond pulsed dielectric barrier discharge in synthetic exhaust gas, prepared from N 2 , O 2 , NO, H 2 O, and C 3 H 6 , over a large range of gas temperature (20-300\r{}C). Results show that the NO x removal rate significantly increased with increasing specific energy deposition. For example, at a temperature of 100\r{}C and an energy deposition of 27 J l -1 , 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 -1 down to ≈4 eV at 7 J l -1 . NO x removal efficiency around 43% was obtained at a temperature of 260\r{}C and a space velocity of 60 000 h -1 for a specific input energy of 27 J l -1 . W values for NO x were less than ≈30 eV. Such treatments in exhaust gas with and without the presence of water vapour induced reactions leading to the production of a large variety of by-products such as acetaldehyde, propylene oxide, formic acid, methyl nitrate, and nitromethane.