Design Factors for $\hbox {NO}_{\rm x}$ Reduction in Nitrogen Plasma

The aim of this paper is to analyze the influence of plasma discharge reactor unit geometries on the efficiency of dry NO_x reduction process in nitrogen plasma environments. The experimental setup consists of the versatile plasma discharge reactor unit powered by 10-kHz pulse HV supply and supplied by mass flow controllers with a simulated (NO + N₂) gas under different concentrations and flowing rates. The measurements are obtained by means of a gas analyzer for NO/NO_x concentration and a digital oscilloscope supplied with HV and current probes for discharge power computation. The number of surface discharge electrodes, the distance between them, their active area, the gas flow rate, and concentration are studied while aiming at 30 g(NO₂)/kWh energy efficiency and higher reduction efficiencies. These targets are the keys to industrial application of plasma discharge reactor, as a way of reducing NO_x from the regeneration phase in the next generation diesel exhaust after treatment system, and the results proved successful.