The principle of power plant desulfurization is mainly to remove sulfur dioxide from coal-fired flue gas by chemical or physical means. Common desulfurization methods include limestone method, gypsum method, calcium oxide method, ammonia method, etc.
Taking the limestone method as an example, its principle is to react limestone with sulfur dioxide in coal-fired flue gas to form gypsum, thus achieving the effect of desulfurization. Specifically, the limestone is crushed and ground into powder, mixed and stirred with water to form an absorption slurry, contacted with flue gas in an absorption tower, and the sulfur dioxide in the flue gas chemically reacts with calcium carbonate in the slurry to generate calcium sulfite, and then generates gypsum through oxidation reaction. Gypsum can be used as a by-product after treatment, while the flue gas after desulfurization is discharged into the atmosphere.
In addition to the limestone method, gypsum method, calcium oxide method and ammonia method are also commonly used desulfurization methods. Gypsum method is to use limestone or lime as desulfurization absorbent, and react with sulfur dioxide in flue gas to produce gypsum. Calcium oxide rule is to use calcium oxide to react with sulfur dioxide to produce calcium sulfite, and then further react to produce calcium sulfate. Ammonia law uses ammonia water to react with sulfur dioxide to produce ammonium sulfate, and then ammonium sulfate is separated by crystallization and precipitation.
The selection of these desulfurization methods depends on specific flue gas composition, desulfurization efficiency requirements, operating costs and other factors. In practical application, power plants will choose suitable desulfurization process according to their own situation and environmental protection policy requirements to achieve the purpose of reducing sulfide emissions and improving environmental quality.
Generally speaking, desulfurization in power plants is an important environmental protection measure. It removes sulfur dioxide from coal-fired flue gas by chemical or physical means, which plays an important role in reducing sulfide emissions and improving environmental quality. With the increasingly strict environmental protection policies and the progress of science and technology, the desulfurization technology of power plants is also constantly developing and improving.