Common flue gas denitrification technologies are mainly the following:

Selective Catalytic Reduction (SCR):

Principle: Under the action of the catalyst, ammonia is sprayed into the flue gas at a temperature of about 280-420℃ to reduce nitrogen oxides to nitrogen and water.

● Chemical reaction formula: 4NO + 4NH₃ + O₂ → 4N₂ + 6H₂O; 6NO₂ + 8NH₃ → 7N₂ + 12H₂O

● Advantages: High denitrification efficiency, generally up to 80%-90%; mature technology and reliable operation.

Selective non-catalytic reduction (SNCR):

● Principle: Without using a catalyst, a reducing agent such as ammonia or urea is sprayed into the furnace temperature area of ​​850-1100℃ to reduce nitrogen oxides to nitrogen.

● Chemical reaction formula: 4NH₃ + 6NO → 5N₂ + 6H₂O; CO(NH₂)₂ + 2NO → 2N₂ + CO₂ + 2H₂O

● Advantages: relatively low investment cost and short construction period.

SNCR - SCR combined denitrification technology:

● Principle: combining the advantages of SNCR and SCR, first denitrification through SNCR, and unreacted nitrogen oxides are further denitrified in the downstream SCR reactor.

● Advantages: reduces costs to a certain extent and improves denitrification efficiency.