Influence of streamer-to-glow transition in NOx removal using pulsed power generator with SOS diodes

Influence of streamer-to-glow transition on NO removal from a simulated diesel exhaust gas in non-thermal plasma reactor is described in this paper. A co-axial cylinder type discharge chamber was used as the pulse streamer discharge non-thermal plasma reactor which was driven by inductive energy storage pulse power generator with fast recovery diode as a semiconductor opening switch. The pulsed power generator supplies 30 kV pulse with 300 pps repetition rate. The co-axial cylinder plasma reactor consists of 1 mm diameter tungsten wire and 19 mm i.d. copper tube with 30 cm length. NO removal from the simulated gas (N2:O2=9:1, Initial NO concentration=200 ppm) increased with input energy into the reactor. The energy efficiency for NO removal was obtained to be 25 g/kWh at 30 % removal in gas flow rate of 2 L/min. However, the energy efficiency decreased to 5 g/kWh with increasing capacitance of the primary capacitor from several hundreds pF to several nF. This decrease was caused by a streamer-to-glow transition.