Tail gas absorption process and device in melamine production process

Abstract

The invention relates to the technical field of tail gas treatment, in particular to a tail gas absorption process and device in the melamine production process. The tail gas absorption process in themelamine production process comprises the following steps that tail gas in the melamine production process enters a water absorption tower after being boosted by a Roots blower, ammonia gas, urea andmelamine in the tail gas are absorbed by water, then the tail gas enters a cyclone separator to be separated,the separated tail gas enters a packing section of an acid absorption tower, ammonia gas in the tail gas is further absorbed by acid absorption liquid, then the tail gas enters a bubble cap section, acid mist is absorbed by desalted water, and finally the tail gas is separated by an efficient demister and is discharged after reaching the standard. According to the tail gas absorption process and device in the melamine production process, ammonia gas contained in tail gas is effectivelyabsorbed, the treated tail gas does not contain acid mist, energy is saved, environment friendliness is achieved, and consumption is reduced.

Description

technical field [0001] The invention relates to the technical field of tail gas treatment, in particular to a tail gas absorption process and device in the production process of melamine. Background technique [0002] In the production process of melamine, solid urea is used as raw material. During the melting process of urea, urea will be decomposed to form a mixed gas of ammonia and carbon dioxide. If this part of gas diffuses into the air, it will cause air pollution. In addition, a large amount of exhaust gas is also produced during the packaging process of melamine. These two parts of the tail gas contain a large amount of ammonia, the concentration is about 4%, and also contain trace amounts of melamine and urea. [0003] The traditional tail gas treatment process absorbs the ammonia gas with water. Because the partial pressure of the ammonia gas is too low, the absorption efficiency is very low. There will be ammonium bicarbonate crystallization, and the absorption ...

AI Technical Summary

Problems solved by technology

[0003] The traditional tail gas treatment process absorbs the ammonia gas with water. Because the partial pressure of the ammonia gas is too low, the absorption efficiency is very low. There will be ammonium bicarbonate crystallization, and the absorption of ammonia gas is not complete

The value of ammonia water is low, storage tanks are required for storage, and there is a certain amount of waste

The tail gas of melamine packaging also contains a large amount of ammonia. If it is not recycled, it will also cause environmental problems and waste ammonia.

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