Method for reducing ammonia content and blasting property of medium-pressure emptying gas

Abstract

The invention discloses a method for reducing ammonia content and blasting property of a medium-pressure emptying gas in urea production. The method comprises the following steps: increasing a packing absorption layer on the lower part of a medium-pressure ammonia absorber, reducing the ammonia content of the medium-pressure emptying gas, and continuously adding 2.2MPa nitrogen into the medium-pressure ammonia absorber equipment for preventing the medium-pressure emptying gas from entering an explosion limit. According to the process method, the ammonia content in the medium-pressure emptying gas is greatly reduced, the ammonia recovery efficiency is high, the operation is simple and reliable, and a liquid level in a medium-pressure inert gas scrubbing tower is easily stabilized. According to the introduced nitrogen, partial pressure of combustible gases such as hydrogen and methane in the emptying gas can be greatly reduced, so that the blasting property of the emptying gas is reduced, and the safety performance of the device is improved.

Description

technical field [0001] The invention relates to the field of urea production technology, and is a process plan for reducing the ammonia content of the medium-pressure vent gas and feeding nitrogen into the medium-pressure vent gas to reduce the explosiveness of the medium-pressure vent gas. Background technique [0002] In the urea production process, the solution containing methylammonium and unreacted ammonia and carbon dioxide from the urea synthesis tower is decomposed and concentrated by high, medium and low pressure, and evaporation systems, and the obtained molten urea is sent to the prilling tower for granulation; The ammonia and carbon dioxide recovered by the first-stage decomposition are sent back to the synthesis tower for recycling through absorption. [0003] In the original urea production process, the non-condensable gas containing saturated ammonia leaving the liquid ammonia storage tank V-05 rises to the ammonia recovery tower (C-05), and contacts the liqui...

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Problems solved by technology

Similarly, if the feedstock CO 2 and H in liquid ammonia 2 and CH 4 If the content is too high, it will also make the vented air form in the dangerous area, increasing its explosiveness

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