Removal of Dilute NH3 Gas from Air Stream by Wet-Electrostatic Precipitator System at Atmospheric Pressure

Ammonia (NH3) gas, which is one of the major odor sources, was removed by the wet electrostatic precipitator (Wet-ESP) system. The Wet-ESP system consists of two steps including the neutralization reaction of NH3 with acid materials and the electrostatic precipitation of dust produced in the neutralization reaction. Two types of acid materials such as nitric acid (HNO3) and sulfuric acid (H2SO4) were used for spontaneous neutralizations with NH3 at room temperature and at atmospheric pressure. The experimental variables were the reaction ratio of NH3 and acid materials, reaction time, the input power of electrostatic precipitator, and total gas flow rate. Both H2SO4 and HNO3 present similar removal efficiency of NH3 and dust emission. The removal efficiency of NH3 was increased with increasing reaction ratio and reaction time. The highest NH3 removal efficiency of more than 99% was achieved under optimum conditions in both acids of HNO3 and H2SO4. At the highest total gas flow rate of 2 m(3)/min, the number concentration of dust in exhaust gas was the same level with that in the air at the input power of 124 W.