The Effect of In Situ Generated Ammonia-Sulfur Aerosols on the Removal of NO_x in a Wet ESP

摘要

The combined removal of sulfur dioxide and oxides of nitrogen (NO_x) have been investigated in a bench-scale pulsed-corona enhanced wet electrostatic precipitator (ESP) with the injection of ammonia and/or ozone. The reaction of ammonia with SO_2 (SO_2, up to 3000 ppm) produces submicron aerosols which catalyzed the reaction and subsequent removal of NO (NO and NO_2, up to 1200 ppm) under certain conditions. Experiments have shown the feasibility of combined SO_2 and NO_x removal from simulated flue gases by the action of these in situ generated ammonia-sulfur aerosols. The total NO_x removal efficiency was ～80% when the ammonia-sulfur aerosols were formed in the presence of 2400 ppm SO_2, 312 ppm O_3 and 2900 ppm NH_3. It was determined that the ammoniasulfur aerosols produced from the reaction of ammonia and sulfur dioxide enhanced the NO_x removal substantially. The significance of this enhancement effect by the in situ ammonium salt aerosols is addressed.