Recently, the deep treatment project of sulfur trioxide removal from coal-fired boiler flue gas of 135MW class in a large petrochemical project contracted by El Environmental Protection has been put into use, and has achieved obvious results. The colored smoke plume has almost completely disappeared and the white smoke plume has been significantly shortened.
With the implementation of the ultra-low emission standard of nitrogen oxides, the problem of increasing SO3 emission concentration caused by SCR becomes serious. The removal efficiency of SO3 by the traditional FGD wet desulfurization process route is low to about 30%. In some areas, the actual emission concentration of SO3 in the boiler flue gas has exceeded SO2, resulting in strong corrosion of chimney equipment. SO3 in the exhaust gas forms a thick sulfuric acid aerosol, which reflects the sunlight to form a light blue plume, which can be thousands of meters to 10 kilometers long without disappearing; When sunlight penetrates the plume, yellowish brown is sometimes observed under the plume, a phenomenon caused by sulphuric acid aerosols.
Sulfuric acid aerosol combined with other chemical components and heavy metal particles played an important role in the formation of haze. This large petrochemical enterprise attaches great importance to environmental protection work, and finally decided to adopt the deep treatment technology of SO3 removal by Sodium-based dry method jointly launched by Aier Environmental Protection and Solvay, Belgium, and carried out the first industrial plant application in China, which achieved the expected effect and eliminated the blue plume. It has made outstanding contributions to improving the local atmospheric environment and haze control.