Removal of SO2 and NOx from Flue Gas by Pulsed Corona Discharges

Abstract

AbstractA pulsed power supply set and a plasma reactor were designed to investigate the process of removal of SO2 and NO using pulsed corona discharge. It is shown that positive pulsed corona is more effective than negative pulsed in removing both SO2 and NO. Using positive pulsed corona, the energy yields for SO2 and NO removed are 64.3 SO2/kWh and 9.9 gNO/kWh, respectively. The amounts of SO2 or NO removed are independent of the initial concentration and primarily determined by the energy absorbed by flue gas. Removal efficiency of 95% of SO2 can be achieved only by ammonia addition (without pulsed voltage). The removal effectiveness and thermal stability of reaction products can be enhanced when exerting a pulsed voltage. Ammonia is critical to SO2 removal and pulsed corona discharge plays a decisive role in NO removal. Ash itself can only remove a small amount of SO2, but the presence of ash in the flue gas reduced the effectiveness of pulsed corona discharge in SO2 removal. Our results indicate that pulsed corona discharges should be operated at temperatures below 80 d̀C.