The impact of SO3 in regenerated flue gas on wet flue gas desulfurization
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I would like to discuss with everyone the impact of SO3 in the regenerated flue gas on wet flue gas desulfurization. If the flue gas at the inlet of the flue gas desulfurization tower contains SO3, will aerosols be generated during the desulfurization process? How to avoid it?
The specific content of SO3 is closely related to the excess oxygen content in the flue gas, the ash content on the furnace tubes, and the content of heavy metal particles in the flue gas. However, with oxygen-enriched regeneration technology, the content of SO3 generally accounts for about 10% of the total sulfides in the flue gas. This portion of SO3 comes into contact with water at the bottom of the scrubber tower, where it rapidly forms sulfuric acid mist; it exists in the form of aerosols before being removed, and is difficult to eliminate merely through washing. This process is unavoidable; only by ensuring proper operating conditions in the filtration section can the removal of SO3 aerosols be guaranteed.
The primary function of Berg’s filtration section is to remove SO3 aerosols. Its principle relies on the acceleration of flue gas as it passes through a Venturi tube, which leads to a decrease in the static pressure of the gas; this allows water to precipitate and continuously condense on the aerosol particles, thereby removing the SO3 aerosols. Therefore, when the feed rate to the system decreases, the amount of flue gas also decreases; the flow rate of the flue gas entering the desulfurization tower becomes too low to allow for acceleration, and as a result, SO3 cannot be removed. This is the main reason why blue smoke is emitted from the chimney.
Does anyone have a good solution for the blue smoke emitted by flue gas caused by SO3?
A common approach is to address SO3 at its source by adding additives.
On top of that, additives are added, and an electrostatic demister is installed in front of the chimney.