The requirement for SCR & SNCR (DeNOx)

In the combustion process, nitrogen reacts with oxygen under high temperatures to form nitrogen oxides (NOx), which include nitrogen monoxide (NO) and nitrogen dioxide (NO2). Meeting stringent emission limits for NOx requires plants to implement DeNOx processes to reduce these emissions to permissible levels.

DeNOx processes typically involve reacting nitrogen oxides in the flue gas with ammonia water or urea at elevated temperatures. Ammonia or urea reacts with both NO and NO2 to convert them into nitrogen (N2), water vapor (H2O), and in the case of urea, carbon dioxide (CO2). Selective Catalytic Reduction (SCR) DeNOx systems are commonly installed in large coal-fired power stations, where they effectively reduce NOx emissions. For smaller to mid-size incineration plants and power stations using Circulating Fluidized Bed (CFB) boilers, Selective Non-Catalytic Reduction (SNCR) technology is often employed to achieve similar emission reduction goals.

By implementing DeNOx technologies like SCR and SNCR, combustion plants improve air quality by significantly reducing NOx emissions, thereby mitigating environmental impacts such as smog formation and acid rain. These technologies not only ensure compliance with emissions regulations but also support sustainable practices in energy production, contributing to cleaner and healthier environments worldwide.