What is the corrosion mechanism of flue gas desulfurization equipment?

Sulfur oxides, oxygen, water, metals, temperature. What do you think?

The main source of corrosion in flue gas desulfurization units is SO2 contained in the flue gas. When sulfur-containing flue gas is under desulfurization conditions, under the action of forced oxidation, SO2 in the flue gas first reacts with water to form H2SO3 and H2SO4, which then react with alkaline absorbents to produce sulfate precipitates that can be separated. At this stage, the process environment temperature is exactly at the level suitable for activation corrosion by dilute sulfuric acid; as a result, the corrosion rate is high and the penetration capacity is strong. Therefore, the intermediate products H2SO3 and H2SO4 are the main causes of equipment corrosion. Furthermore, NOX contained in the flue gas, the water in the absorbent slurry, and the chloride ions present in the water (chloride ion corrosion has a greater impact in the seawater method) also possess corrosive properties toward the metal matrix.