Operating parameters optimization and efficient NO reduction of SNCR process in a municipal solid waste incinerator

In this study, the NO reduction process in the Selective non-catalytic reduction (SNCR) system of a waste incinerator was analyzed by numerical simulation, and the effects of droplet size (120 to 200 μm), velocity (34 to 50 m/s), and atomization angle (30° to 50°) on the NO removal efficiency of SNCR were studied. The three parameters investigated showed an influence on the NO removal efficiency of the SNCR system. A maximum of NO removal efficiency with a corresponding minimum of NH₃ slip could always be found by modifying the three parameters within the ranges investigated. The highest NO removal efficiency obtained within the operating window investigated was 52.7 %, which also yielded the lowest NH₃ slip, i.e. 5.69 ppm. The maximum removal efficiency was achieved with an atomization angle of 35°, velocity 42 m/s, and 180 μm droplet size of reducing agent. Among the evaluated parameters, droplet size exerted the most significant impact on NO removal efficiency. It is therefore recommended that suitable droplet size range should be determined first when optimizing the NO removal efficiency of SNCR systems in waste incinerators.