Method and system for treating exhaust gas containing ammonia and ammonium sulfide

Abstract

The invention discloses a method and system for treating exhaust gas containing ammonia and ammonium sulfide. The method comprises leaching exhaust gas containing ammonia and ammonium sulfide througha NaOH solution in an alkaline washing zone, absorbing ammonia gas in an ammonia absorption zone, oxidizing unabsorbed ammonia gas through ozone in a UV photolysis zone and carrying out discharge. Thesystem comprises the alkaline washing zone, the ammonia absorption zone, the UV photolysis zone and an ammonium bicarbonate reaction zone. One end of the ammonia absorption zone is communicated withthe alkaline washing zone. The other end of the ammonia absorption zone is communicated with the UV photolysis zone and the ammonium bicarbonate reaction zone. Compared with the prior art, the methodand system for treating exhaust gas containing ammonia and ammonium sulfide realize a low production cost. The system has low maintenance frequency, a high rate of reaching the designed standard, a low operation cost and a low ammonium bicarbonate production unit comprehensive cost, saves energy, is environmentally friendly and has high economic efficiency and social benefits.

Description

technical field [0001] The invention belongs to the field of atmospheric treatment, in particular to a method and system for treating waste gas containing ammonia and ammonium sulfide. Background technique [0002] At present, the treatment method of industrial waste gas containing ammonia and ammonium sulfide mostly adopts physical absorption method, using soft water or dilute ammonia water as absorbent to absorb ammonia in industrial tail gas, and the obtained low-concentration ammonia water is further distilled to obtain concentrated ammonia water, and then rectified into concentrated ammonia gas , and then pressurized and condensed to make liquid ammonia for use. The disadvantages of this method are: 1. consume a large amount of water; 2. a large amount of dilute ammonia water produced in the ammonia absorption process must be concentrated into 20% ammonia water by heating and can be used, which consumes a lot of energy; 3. the ammonia recovery rate is not high, resultin...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: 1. consume a large amount of water; 2. a large amount of dilute ammonia water produced in the ammonia absorption process must be concentrated into 20% ammonia water by heating and can be used, which consumes a lot of energy; 3. the ammonia recovery rate is not high, resulting in The loss of synthetic ammonia; ④ Incomplete water washing needs to burn the escaping ammonia gas, which will produce a certain amount of NO x , causing secondary pollution

Therefore, the physical absorption method for industrial ammonia-containing waste gas treatment needs to be improved and optimized. It is difficult to achieve high-efficiency treatment and comprehensive recycling of high-concentration ammonia-containing industrial waste gas by using a single method

[0003] In addition, some industrial ammonia-containing waste gas treatment processes use pickling towers for spray scrubbing treatment, but during the treatment process, due to the increase in the concentration of ammonium sulfate in the waste gas, it is easy to cause crystallization in the tower, which makes the circulation pump and nozzles at the bottom of the absorption tower often blocked. , and will produce H 2 S is highly toxic and has potential safety hazards

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