Methods of desulfurization and denitrification Six methods of desulfurization and denitrification

The main equipment of the process is an activated carbon fluidized bed adsorber similar to a super adsorption tower. In the adsorber, SO2 in flue gas is oxidized to SO3 and dissolved in water to form dilute sulfuric acid aerosol, which is then adsorbed by activated carbon. Ammonia gas is injected into the adsorption tower, and ammonia gas and nitrogen oxides generate N2 under the catalytic reduction of activated carbon, and the activated carbon adsorbed with SO2 can enter the desorption tower for heating and regeneration.

2. Tin oxide method

WSA-SNOx method is a wet washing and nitrogen oxide removal technology. In this process, flue gas first passes through SCR reactor, and nitrogen oxides are reduced to N2 by ammonia under the action of catalyst, and then the flue gas enters the reforming furnace, where SO2 is oxidized to SO3 by solid catalyst, and SO3 enters WSA condenser after passing through flue gas reheater GGH, and is absorbed by water and converted into sulfuric acid.

3. Nokso method

A fluidized bed absorber is arranged downstream of the electrostatic precipitator, and γ-Al2O3 balls impregnated with sodium sulfate are used as the absorber. After absorbing nitrogen oxides and SO2, the absorbent is reduced by reducing gas (CO, CH4, etc.). ) generate H2S and N2 at high temperature.

4, high energy particle ray method

High energy particle beam method includes electron beam (EBA) method and plasma method. Its principle is that some molecules in flue gas are ionized by high-energy particles (ions) to form active free radicals and free electrons, and nitrogen oxides in flue gas are oxidized. This technology can not only remove nitrogen oxides and SO2 from flue gas, but also remove heavy metals and other substances.

5. Wet flue gas desulfurization plus metal chelation method

Zhong Zhaoping invented the absorption liquid of flue gas desulfurization and denitrification by jet bubbling method, which includes lime or limestone slurry, water-soluble organic acid accounting for 0.05% ~ 0.5% (mass fraction) of lime or limestone slurry and iron-based or copper-based metal chelate accounting for 0.03% ~ 0.3% (mass fraction) of lime or limestone slurry.

6. Chloric acid oxidation method

Due to the strong oxidation of chloric acid, the oxidation absorption solution containing chloric acid can simultaneously remove sulfur and denitration, with the desulfurization rate reaching 98% and denitration rate reaching over 95%, and toxic trace metal elements can also be removed. In addition to desulfurization and denitrification with chloric acid, NaClO3/NaOH can also remove SO2 and nitrogen oxides at the same time, and achieved good results.