A cold recovery equipment and method for ammonia in the vent gas of a synthetic ammonia storage tank

Abstract

The invention provides a device and a method for cold recycling of ammonia in synthetic ammonia storage tank purge gas. The device for cold recycling of ammonia in the synthetic ammonia storage tank purge gas comprises that a first-stage ammonia recycling tower is connected in series with a second-stage ammonia recycling tower, tower internal structures are the same, an ammonia outlet of the second-stage ammonia recycling tower is connected with an inlet of an ice machine inlet gas separator through a pipeline, and a gas ammonia outlet arranged on the top of the ice machine inlet gas separator is connected with an ice machine through a pipeline. The method using the device includes the specific steps: 1, the ammonia recycling towers cools, drops the temperature and recycles ammonia; and 2, gas ammonia is circulatingly absorbed by liquid ammonia of the first-stage ammonia recycling tower; liquid ammonia of the second-stage ammonia recycling tower is used as a refrigerant through an ammonia cooling section, then goes to the ice machine station, is evaporated, has the temperature dropped and is congealed, and then returns back to a synthetic liquid ammonia storage tank. The device and the method have the advantages that the two-stage ammonia recycling tower is newly added, the recycling rate of ammonia of the purge gas is increased, the dilute aqua ammonia yield is reduced, the urea hydrolysis load is reduced, and expected economic benefits are achieved.

Description

technical field [0001] The invention relates to an ammonia recovery process, which belongs to the field of ammonia separation and recovery, in particular to a cold recovery equipment and method for ammonia in the exhaust gas of a synthetic ammonia storage tank. Background technique [0002] The current non-powered ammonia recovery is a method of relaxation gas ammonia recovery. The ammonia content in the tail gas of the unpowered ammonia recovery outlet is high, and the recovery rate of ammonia is low. In addition, the current isobaric ammonia recovery tower needs to use cooling water to cool the tower or The ammonia water outside the tower consumes power; the isobaric ammonia recovery tower uses cooling water to cool the ammonia water inside or outside the tower. Because the temperature of the cooling water is relatively high, the temperature of the ammonia water in the isobaric ammonia recovery tower will be higher. Absorbing ammonia at a higher temperature is unfavorable ...

AI Technical Summary

Problems solved by technology

[0002] The current non-powered ammonia recovery is a method of relaxation gas ammonia recovery. The ammonia content in the tail gas of the unpowered ammonia recovery outlet is high, and the recovery rate of ammonia is low. In addition, the current isobaric ammonia recovery tower needs to use cooling water to cool the tower or The ammonia water outside the tower consumes power; the isobaric ammonia recovery tower uses cooling water to cool the ammonia water inside or outside the tower. Since the temperature of the cooling water is relatively high, the temperature of the ammonia water in the isobaric ammonia recovery tower will be higher

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