Conversion of Nitric Oxide to Nitrogen Dioxide Using Hydrogen Peroxide

Detailed chemical kinetic model of hydrogen peroxide (H₂O₂) into diesel exhaust gas has been executed to investigate its effect on the removal of nitric oxide(NO) by changing exhaust gas temperature and H₂O₂ addition amount. Flux analysis has also been done to clarify which reaction mainly affects NO-to-NO₂ conversion. From the results of this study, it is shown that the optimal temperature condition to maximize the removal of NO exists near at 500K for OH addition condition, while that for H₂O₂ addition exists near at 800K. It is also shown that temperature window for the removal of NO becomes widened as the initial temperature of the exhaust gas increases, and NO-to-NO₂ conversion rate decreases in proportion to the concentration of hydrocarbon(HC), although that of the total NOx remains the same level regardless of HC concentration. Finally, it is shown that HO₂ + NO → NO₂ + OH is mainly responsible for NO-to-NO₂ conversion.