Desulfurization system and desulfurization process thereof

Abstract

The invention discloses a desulfurization system comprising a tower body, wherein a smoke inlet is arranged in the middle of the tower body; a pure smoke outlet is arranged at the top of the tower body; a slurry pool for containing slurry is formed on the lower part of the tower body; the slurry pool is provided with a mixed liquid outlet; a slurry spraying layer, a rising air gap and a clean water spraying layer are sequentially arranged from the smoke inlet to the pure smoke outlet from bottom to top; the bottom of the slurry pool is respectively connected with an oxidization mechanism and an ammonia supplying mechanism; and the desulfurization system further comprises a slurry circulating mechanism and a clean water circulating mechanism. The invention further provides a desulfurization process; and the process is low in water consumption amount so that the amount of saturated steam in pure smoke is reduced by 30-40% and consumption of external clean water is reduced. According to the desulfurization system and the desulfurization process disclosed by the invention, the operation cost is low; and the consumption of the steam is 20% of that of an ammonia-fertilizer method process and the consumption of power is 40% of that of the ammonia-fertilizer method process. The escaping rate of ammonia is low; the content of the ammonia in the pure smoke is less than 8mg / Nm<3>; no three wastes are discharged; and secondary pollution to an environment is not caused.

Description

technical field [0001] The invention relates to the field of chemical gas desulfurization, in particular to a boiler flue gas desulfurization system and a desulfurization process thereof. Background technique [0002] The current wet ammonia desulfurization technologies mainly include ammonia-fertilizer method, ammonia-acid method and ammonia-ammonium sulfite method. [0003] 1) Ammonia-fertilizer desulfurization technology [0004] Ammonia water is used as the desulfurization agent, and a large amount of ammonium sulfate and ammonium sulfite solutions are circulated in the desulfurization tower to make them react with SO in the flue gas. 2 reaction to remove SO 2 , to generate ammonium sulfate and ammonium sulfite as by-products, and use air aeration at the bottom of the desulfurization tower to oxidize ammonium sulfite into ammonium sulfate. After the ammonium sulfate solution is discharged, it is filtered, evaporated, centrifuged, and dried to produce ammonium sulfate c...

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Problems solved by technology

[0009] The above three methods all have the following defects: after the heat and mass transfer between the flue gas and the circulating slurry, the flue gas is discharged into the atmosphere in the state of saturated wet flue gas, the flue gas contains a large amount of water vapor, and the desulfurization device consumes a lot of water. Water-scarce areas in the west restrict the use of ammonia desulfurization; the utilization rate of ammonia is low, and some gaseous ammonia easily escapes with flue gas, causing secondary pollution

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