Plasma Aftertreatment For Simultaneous Control Of Nox And Particulates

Plasma reactors can be operated as a particulate trap or as a NO(subscript x) converter. The soluble organic fraction (SOF) of the trapped particulates can be utilized for the oxidation of NO to NO2. The NO2 can then be used to non-thermally oxidize the carbon fraction of the particulates. This paper examines the energy density required for oxidation of the SOF hydrocarbons and the fate of NO2 during the oxidation of the particulate carbon. The energy density required for complete oxidation of the SOF hydrocarbons is shown to be unacceptably large. The reaction of NO2 with carbon is shown to lead mainly to backconversion of NO2 to NO. These results suggest that the use of a catalyst in combination with the plasma will be required to efficiently reduce the NO(subscript x) and oxidize the SOF hydrocarbons.