Removal of NO in Mist by the Combination of Plasma Oxidation and Chemical Absorption
A coaxial nonthermal plasma (NTP) reactor was used for oxidizing and removing NO in mist. The effects of gas/mist components on O3 formation, NO oxidation, and NOx removal by NTP in simulated flue gas after wet desulfurization were investigated. The presence of mist results in the significant decrease of O3 concentration. Formation of active species, such as OH and HO2, would promote the reactions between NO and OH/HO2. Thus, the NO oxidation, NOx removal, and energy efficiency are significantly improved in the presence of mist. The promotion effects of mist component on the NO oxidation and NOx removal follow the order: Na2SO3 mist FeSO4 mist Na2SO4 mist. Increase of the mist pH can enhance the absorption of nitrogen oxides with the mist. Adding SO2 to the gas mixtures or raising the NO2/NOx ratio of simulated gas increases the NOx removal efficiency. This process demonstrates that NO oxidation by NTP and subsequently absorption by mist are feasible and have great value to practical application.