抄録
Due to the relatively high performance and the compactness, the pulsed-discharge deNOx process is expected to be one of the next generation technologies to suppress air pollution. However, sufficient guide lines for the optimum operation of pulsed-discharge deNOx process has not been presented. In this study, we have simulated numerically the process applied by several hundreds pulsed-voltages, and investigated the effects of by-products and ammonia injuction on the deNOx performance. In a case for the no ammonia injection, both of the NxOy removal efficiency and the electric energy consumption to remove NxOy change with increasing repetitive pulse number, because electrons produced by the discharge recombine with accumulated by-products, such as of H3O + (H2O)2, followed by decreasing radical concentration and oxidative/reductive removal reactions. In a case for ammonia injection, the removal efficiency increases and the electricity consumption decreases with increasing the ammonia concentration, because removal reactions such as NO →O NO2 →OH HNO3 →NH3 NH4NO3 and NO →NH2 N2 become active. When ammonia is injected excessively, the deNOx performance declines because the NH2 radical produced by the electron collision with ammonia reacts with NO2 to make relatively stable N2O.
