Dual-course Dielectric Barrier Discharge with a Novel Hollow Micro-Holes Electrode to Efficiently Mitigate NOx

The effect of a novel hollow annular micro-hole electrode on the DBD de-NOx performance was investigated. The experimental results show that the hollow electrode allows the feed gas to take full advantage of the redundant heat of the electrode, thus reducing the energy consumption of the system. Subsequently, the micro-hole structure can improve the uniformity of feed gas in the plasma channel and prolong the residence time of the feed gas in the plasma channel. The reactor can also raise the temperature of the feed gas and enhance the plasma electric field. The optimum NOx removal efficiency of about 82.6% is achieved at 16 annular micro-holes. Compared to the rod electrode reactor, the novel electrode reactor shows 19.7% reduction in energy consumption and 13.2% enhancement in de-NOx efficiency. The calculations of de-NOx mechanism show that the NO2 concentration decays significantly as the feed gas residence time increases, accompanied by a slight increase in N2O concentration. The NO2 concentration marginally increases while N2O concentration slightly decreases as the increase of feed gas temperature. DBD de-NOx presents the mode of accelerated reduction of NO, essential removal of NO2, and gradual consumption of N2O with the reduced electric field increases. Environmental implication The traditional DBD usually suffers from some problems in the treatment of hazardous gas NOx and others, such as high heat loss, low conversion efficiency and uneven treatment. In this paper, it is proposed to optimize the reactor structure by using a novel dual-course hollow electrode with annular micro-holes. The hollow structure can be used as a preheating channel of the hazardous gases, diminishing the heat loss. The number of micro-holes modulates the conversion efficiency of hazardous gases and makes the plasma channel more uniform through. The novel structure is of great significance to the advanced treatment of hazardous gases.