$\hbox {NO}_{\rm x}$ Aftertreatment Using Thermal Desorption and Nitrogen Nonthermal Plasma Reduction

In this paper, the results of two experiments are reported. First, the performances of various types of nonthermal plasma reactors for NO_x reduction were compared. It was shown that the surface-discharge reactors have as high NO_x reduction capabilities as pulse-powered wire-cylinder reactors. Second, NO_x treatment using the surface-discharge reactor with a NO-adsorbent zeolite 13X was performed. Thermal desorption was employed for the regeneration of the zeolite. The NO_x of 350 ppm was kept lower than 18 ppm for at least 11 h, whereas it degraded to 75 ppm in the absence of the regeneration. The result suggested the possibility of an aftertreatment system that employed thermal desorption by utilizing the waste heat of diesel engine exhaust and NO_x reduction by using a surface-discharge reactor.