Experimental study on the influence of H2O vapor and O2 for desulfurization and denitrification of the diesel exhaust in marine application by non‐thermal plasma

Abstract

Abstract To improve the pollutant removal efficiency by non‐thermal plasma (NTP), the effect of H2O vapor and O2 on removal efficiency of NO and SO2 as well as the reduction of CO was investigated in H2O/O2/SO2/NO/C3H6/CO2/N2 system. To analyse the reaction mechanism, the effects of H2O vapor and O2 on the emission intensity of O(3p5P→3s5S20) and OH(A2∑+→X2∏) were investigated. The experimental results show that the increase of H2O vapour (0%–9.8%) promotes the generation of OH radicals, increases the removal efficiency of NO from 18.9% to 57.3%, decreases the energy per NO removed from 449.0 to 148.1 eV/NO, increases SO2 removal efficiency from 4.8% to 35.3%, decreases the energy per SO2 removed decreases from 2784.0 to 582.9 eV/SO2, and reduces the generation of CO from 460 to 229 ppm. In the range of 0%–15%, the increase of O2 content promotes the formation of O radicals, increases the removal efficiency of NO from 8.5% to 54.2%, and decreases the energy per NO removed from 994.3 to 156.4 eV/NO. In the range of 0%–5%, increasing O2 content promotes SO2 removal efficiency from 8.7% to 24.8%, and decreases the energy per SO2 removed from 2485.7 to 876.6 eV/SO2. However, CO generation increases from 200 to 350 ppm with the increase of O2 in 0%–5% due to the incomplete oxidation of C3H6. In the range of 5%–15%, the increase of O2 produces more O radicals, decreases the removal efficiency of SO2 from 24.8% to 23.5% and the generates of CO from 350 to 311 ppm. This study is helpful for improving the efficiency of NTP for desulfurization and denitrification, while reducing the by‐product CO.

Keywords

• air pollution control
• carbon compounds
• flue gas desulphurisation
• gas mixtures
• hydrogen compounds
• marine pollution