| 摘要 |
<p>PURPOSE: To treat a flue gas efficiently with a small volume apparatus without using acid solution by removing sulfur dioxide by contacting a magnesium- enhanced lime scrubbing aqueous slurry with a gaseous stream, and returning gypsum by-produced to a wet scrubbing unit. CONSTITUTION: A gas containing sulfur dioxide, such as a combustion flue gas, is introduced into a wet scrubbing unit 1, and a magnesium-enhanced aqueous scrubbing slurry is sprayed from a spray nozzle 13. Then, sulfur dioxide is removed from the flue gas and a clean gas is obtained. In the unit 1, a solid portion of the slurry mainly formed of calcium sulfite increases up to 13-20 wt.% and the pH of the slurry is maintained between 4.5-5.6. Then, a discharging stream of the slurry is introduced into an oxidizing unit 19, gypsum and magnesium sulfate are produced, the gypsum is recovered, and magnesium sulfate is dissolved into a water solution and returned to the wet scrubbing unit 1.</p> |
