High temperature denitrification catalysis in power plants

Definition of SCR flue gas denitrification technology

Answer: Selective Catalytic Reduction (SCR) technology is a process of injecting reducing agents such as ammonia or urea into the flue gas upstream of the catalyst. At a temperature of 180-450 ℃, the catalyst (with the appropriate type of catalyst selected based on the flue gas temperature) catalyzes the reduction of NOx in the flue gas to N2 and H2O without secondary pollution. Due to its selectivity, NH3 only reacts with NOx within the above temperature range and does not react with O2, hence it is called selective catalytic reduction denitrification technology.

4NH3+4NO+O2 →4 N2+6H2O

2NH3+NO+NO2 →2 N2+3H2O

2NO2+4NH3+O2 →3 N2+6H2O

High temperature denitrification catalysis in power plantsThe catalyst used in the selective catalytic reduction (SCR) denitrification system of power plants is a substance that promotes the selective chemical reaction between the reducing agent and nitrogen oxides in the flue gas at a certain temperature during the SCR reaction.

At present, most commercial SCR catalysts are based on TiO2 as the carrier, V2O5 as the main active component, and WO3 and MoO3 as antioxidant and anti toxic auxiliary components. Catalyst types can be divided into three types: plate type, honeycomb type, and corrugated plate type.

High temperature denitrification catalysis in power plantsThe catalyst plate is made of a metal mesh pressed from a stainless steel metal plate as the substrate, and a mixture of TiO2, V2O5, etc. is adhered to the stainless steel mesh. After compression and calcination, the catalyst plate is assembled into a catalyst module.