Method and device for producing ammonium hydroxide by ammonia synthesis purge gas system

Abstract

The invention discloses a method and device for producing ammonium hydroxide by an ammonia synthesis purge gas system. The device comprises an ammonia absorption tower, an ammonia stripping tower, anammonium hydroxide tank, an ammonium hydroxide heat exchanger, an ammonium hydroxide water cooler and an ammonium hydroxide reboiler. The ammonia absorption tower is connected with a front-end ammoniasynthesis system and used for absorbing ammonia synthesized by the front-end ammonia synthesis system. The ammonia stripping tower is communicated with the ammonia absorption tower through a first pipeline and a second pipeline, and a circulating pipeline is arranged on the side wall of the ammonia stripping tower. The ammonium hydroxide tank is communicated with the ammonia absorption tower through a third pipeline and used for producing ammonium hydroxide in different concentrations. The ammonium hydroxide heat exchanger is used for heat exchange of substances in the first pipeline and thesecond pipeline. The ammonium hydroxide water cooler is arranged on the first pipeline. The ammonium hydroxide reboiler is arranged on the circulating pipeline. The method and the device have advantages that consumption of medium pressure steam in the purge gas system is reduced, energy saving and consumption reduction are realized, system operation is stabilized, and an ammonium hydroxide productis added.

Description

technical field [0001] The invention belongs to the technical field of synthetic ammonia, and in particular relates to a device and method for producing ammonia water by utilizing a gas release system of synthetic ammonia. Background technique [0002] Synthetic ammonia refers to the direct synthesis of ammonia from nitrogen and hydrogen under the action of high temperature, high pressure and catalyst. In chemical plants, synthetic ammonia can provide raw materials for subsequent production. It is the main source of chemical fertilizers, refrigerants and chemical raw materials, and plays an important role in production and operation. . [0003] In the ammonia synthesis plant, a large amount of air is added to the front-end reforming system, and the inert gas in the air does not participate in any reaction, and eventually accumulates in the synthesis loop, which not only increases the power consumption of the synthesis gas compressor, but is also detrimental to the ammonia sy...

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Problems solved by technology

Usually, the purge gas first enters the ammonia absorption tower and is recovered in the form of ammonia water to generate ammonia water with a concentration of 18%-19%, and then sends the generated ammonia water to the ammonia stripping tower for heating and stripping with medium-pressure steam to recover The ammonia gas is cooled and enters the ammonia water tank. In order to ensure that the ammonia content in the purge gas at the outlet of the ammonia absorption tower is qualified, two tons of stripping steam is consumed per hour, and stripping temperature fluctuations often occur during operation, which affects the steam Improve the effect

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