Detaching, desorbing method for synthesizing ammonia liquor of refined ammonia

Abstract

This invention discloses a method for refining ammonia solution with separate desorption. The method comprises: (1) heat-exchanging the ammonia solution from the washing device of regenerated gas with a heat exchanger, introducing into a desorption column, and introducing steam to heat and desorb NH3 and CO2; (2) sending the desorbed gases containing NH3 and CO2 into a urea recovery system, returning the residual desorption solution to the desorption heat-exchanger, heat-exchanging, and mixing with the residual desorption solution from the urea-desorption system; (3) introducing part of the mixed desorption solution into the gas-generation section, and returning the rest mixed desorption solution to the washing device of regenerated gas through a water-cooling heat-exchanger for recycling. The refined ammonia solution does not contain urea. The method, through separate desorption, can decrease desorption load, increase the concentrations of NH3 and CO2, and reduce the cost. The refining desorption solution and the urea desorption solution, after mixed, are recycled into the refining, regenerating washing device, thus can reduce system desalted water consumption and reduce the cost. The residual desorption solution can be recycled, thus reducing the environmental pollution.

Description

technical field [0001] The invention relates to a method for treating refined ammonia water in a synthetic ammonia production process, in particular to a method for separately desorbing synthetic ammonia and refining ammonia water. Background technique [0002] In the prior art, the dilute ammonia water from the refining ammonia purification tower is mixed with the ammonia water from the urea system and then enters the desorption heat exchanger for heat exchange. After heat exchange, the mixed ammonia water from the refining and urea system enters the desorption tower and feeds steam for desorption. get NH 3 and CO 2 The desorbed gas is circulated back to the urea system, and the desorbed raffinate containing Ur is cooled by the cooler and then discharged. In this method, the refined ammonia water is mixed with the urea-containing ammonia water from the urea system and then enters the desorption tower, which increases the desorption load and steam consumption, resulting in...

AI Technical Summary

Problems solved by technology

In this method, the refined ammonia water is mixed with the urea-containing ammonia water from the urea system and then enters the desorption tower, which increases the desorption load and steam consumption, resulting in insufficient desorption. If it is sent to gas generation or recycled to the refining regeneration washing device, it will easily cause urea crystallization blockage, aggravate equipment corrosion, and increase maintenance and production costs