The principle of desulfurization and denitration is to restore the generated NOX to N2 and remove NOX from the flue gas. According to the treatment process, it can be divided into wet denitrification and dry denitration.

They include acid absorption, alkali absorption, selective catalytic reduction, non selective catalytic reduction, adsorption, and plasma activation.

Desulphurization and denitrification simply means the process of using alkali neutralization acid and desulphurization is removal of sulfur dioxide contained in the boiler flue gas, which is the removal of nitrogen oxides contained in the flue gas of the boiler.

The process of desulphurization is to make alkaline desulfurizer (such as limestone, CaO, sodium hydroxide, etc.) into slurry, mixed with boiler flue gas, sulphur dioxide into acid, and reaction with alkaline desulfurizer to produce CaSO4 (calcium sulphate) final product, such as the principle of denitrification and desulphurization, that is, denitrifying agent is changed into ammonia or urea.