Applications that require a high NOx reduction level, the most feasible technology is often Selective Catalytic Reduction (SCR) as it provides a reduction rate up to 95%. In SCR of NOx nitrogen oxides are reduced to water and molecular nitrogen in an SCR reactor. The purpose of the catalyst is to speed up the reaction.
The SNCR and SCR technologies can also be used together to ensure low emission levels and minimize the catalyst size.
Valmet CFB technology is applied in this large biomass fired boiler located in Copenhagen city center. The boiler is equipped with both, SNCR and SCR technologies to reach ultra-low NOx and NH3 emission levels in the stack. The catalyst is located on the high dust side before other flue gas cleaning equipment and its performance is followed regularly with laboratory tests to ensure high NOx reduction rate all the time. Vaporized ammonia is used to reach effective mixing between flue gas and ammonia.
Start-up in 2019
Fuel: Wood chips