Nitric oxide removal from flue gas using dielectric barrier discharge coupled with negative pulse corona

Abstract

To optimize the efficiency of nitric oxide (NO) removal, a new catalyst-free method at room temperature was developed by combining dielectric barrier discharge (DBD) and negative pulse corona (NPC). With this method, the effects of applied current, initial NO concentration, gas flow rate, O2 concentration, methanol addition, and the selection of applied current and gas flow rate on NO removal were investigated respectively. Results showed that increasing current not only promoted the NO removal but also reduced NO2 and N2O formation. The NO removal efficiency had a negative dependence on initial NO concentration and gas flow rate. A negative effect of O2 on NO removal was observed, and it also promoted the formation of NO2. However, adding methanol was able to mitigate the negative effects and eliminate NO2 exhaust. The addition of 0.5 vol% methanol raised NO removal efficiency from 30.9% to 98.6% under the condition of 1.67 A, 500 ppm NO, 0.625 L/min with 8 vol% O2 in the flue gas. The reaction path of NO removal process was strongly altered as methanol added into DBD-NPC processing. NOX (NO, NO2) can be reduced to N2 with CH3OH as a reductant. A simple combined denitration method (DBD-NPC) without the assistance of selective catalytic reduction (SCR), additional heating and pressure was developed and evaluated, which may provide potential applications for denitration industry.