Experimental And Theoretical Study On Flue Gas Denitrification By DC Corona Oxidation Integrating With Chemical Scrubber

It is a promising technology for flue gas pollution control to remove NO_X by DC corona oxidation integrating with chemical scrubber. Advantages of the technology have been found such as low energy consumption, no secondary pollution from ammonia leakage, removing NO_X and SO₂ simultaneously with the original equipment installed for wet flue gas desulfurization or semi-dry flue gas desulfurization. In addition, for reducing equipment investment, it can also be integrated with wet ESP to achieve removing dust, NO_X and SO₂ simultaneously. The process of NO corona oxidation is the key that decides the performance of this technology. The thesis focused on the study of NO corona oxidation under radical showers induced by DC corona discharge.Numerical simulation of electric field in the reactor was carried out by finite element method. The result presented theoretical basis of the technology, and instructed the experimental study which is for either the structure optimization of the nozzle electrode or the selection of the clearance of a multi-electrode reactor.Experiments showed the formation of ozone radical and the mechanism of NO oxidation under different additional gases, and the feasibility and energy saving of the technology were validated. The following were concluded, strong electric field was formed near the region of nozzle exits, and electrons affected by strong electric field were of high energy. The electrons with high energy made oxygen dissociated, and produced radicals such as ozone etc oxidizing NO. Ozone concentration decreased remarkably during the process of NO oxidation. Furthermore, the dissociated probability of N₂ in the flue gas was much smaller than that of O₂ near the region of nozzle exits.It is practical for engineering application to select air, water and oxygen being the components of additional gas. Additional gas for practice can be obtained by their reasonable combination of certain oxygen concentration and certain humidity. Experimental results showed considerable effect of oxygen concentration and humidity of additional gas on the efficiency of NO_X removal and energy consumption. In general, the efficiency of NO oxidation and energy efficiency improved with the increase of oxygen concentration in additional gas if discharge power keeps unchanged. And the higher the power was, the greater the influence got. The effects of oxygen concentration...