Flue gas desulfurization process.

摘要

In a flue gas desulfurization process comprising a cooling step of cooling and dedusting a sulfur oxides (SOx)-containing flue gas (1) an absorption step of contacting in an adsorption tower (7) the flue gas cooled in the cooling step with a limestone slurry to absorb and remove SOx in the gas, and an oxidation step of oxidizing the resulting slurry containing calcium sulphite and/or calcium hydrogen sulfite, by contacting it with an oxygen-containing gas to form a gypsum slurry from which gypsum is separated, in order to subject slurry of the absorption tower (7) to oxidation treatment to thereby obtain gypsum, without passing the slurry through a pH-adjusting tank and an oxidation tower, a process is employed wherein a portion of the flue gas at the exit of a cooling tower (5), freed from dust and acidic gases is sucked by a fan (201), followed by contacting it with the slurry in a reactor (202) to neutralize unreacted CaCO₃ with SOx in the flue gas and also oxidize calcium sulfite and/or calcium hydrogen sulfite formed herein and in the absorption tower (7) by oxygen in the flue gas.