Process Principle of SCR Denitrification Equipment

What is SCR Denitrification?

SCR denitrification refers to the Selective Catalytic Reduction denitrification technology, also known as ammonia catalytic reduction denitrification technology. Its principle involves injecting a certain amount of ammonia or other suitable reducing agents into the flue gas from boilers or kilns upstream of the catalyst. Under the action of the catalyst, within a temperature range of 200-450°C, NOx in the flue gas is converted into nitrogen and water.

The process flow of SCR denitrification equipment typically includes the following steps:

1. Flue gas pretreatment stage: The flue gas first undergoes processes such as dust removal and desulfurization for preliminary treatment before entering the SCR denitrification reactor. Key parameters such as NOx concentration and temperature in the flue gas are controlled to ensure the efficiency of the SCR denitrification reaction.

2. Ammonia injection stage: In the SCR denitrification reactor, ammonia water as a reducing agent is injected into the flue gas. Ammonia water can be introduced into the flue gas through methods such as solution spraying or aerosol spraying. The amount of ammonia injected is adjusted based on multiple parameters, including NOx concentration and temperature in the flue gas.

3. Catalytic reaction stage: NOx in the flue gas reacts with ammonia under the action of the catalyst, undergoing a chemical reaction to produce nitrogen and water. The catalysts used are typically metal oxides or metal salts such as vanadium, tungsten, molybdenum, or carriers like silica gel.

4. Flue gas post-treatment stage: After denitrification in the SCR denitrification reactor, the flue gas from boilers or kilns needs to be treated through post-treatment equipment.