Energy-saving optimization technology of deep hydrolysis system for improving urea production capacity

Abstract

The invention belongs to the technical field of urea production, discloses a urea production technology applied to an aqueous solution total recycle process, a CO2 vaporizing extract process, an NH3 vaporizing extract process and the others, and particularly discloses an energy-saving optimization technology of a deep hydrolysis system for improving urea production capacity, of which the operation pressure is within a range of 1.1-2.5Mpa. A gas phase ejected by a stripping-hydrolyzing tower is directly led to a resolving device (a rectifying tower) of a low-pressure system by a stripping-hydrolyzing single tower technology; the top gas-phase heat of the stripping-hydrolyzing tower can be recycled to the maximal extent; excessive moisture is limited in an urea solution of the low-pressure system, so that the water/carbon ratio of urea synthetic tower material is controllable. Thus, the transformation rate of CO2 in urea synthesis is improved, production energy consumption of unit urea is reduced, and the value is lower than the design value. By adopting the energy-saving optimization technology, reflux liquid in the existing stripping-hydrolyzing single tower technology is also removed, energy consumption and investment on equipment are further reduced, and the operation of the system is simplified.

Description

technical field [0001] The invention relates to urea production, in particular to an energy-saving optimization process for a deep hydrolysis system that improves the production capacity of urea, which not only actively regulates the water-carbon ratio of the urea synthesis tower, but also improves the CO 2 conversion rate, thereby increasing urea output, and can also greatly reduce energy consumption in the urea production process, simplify the process flow of the deep hydrolysis system, and reduce investment. It belongs to the field of urea production technology and can be used for aqueous solution full circulation method, CO 2 Steam stripping, NH 3 Steam stripping and other urea production processes. technical background [0002] As far as the production process of the urea plant is concerned, the treatment of the process condensate has changed from the original desorption tower, that is, only the ammonia (NH 3 ) and carbon dioxide (CO 2 ), which contains about 1% urea...

AI Technical Summary

Problems solved by technology

[0005] The present invention overcomes the defects and deficiencies of existing deep hydrolysis devices, and invents an energy-saving optimization process for deep hydrolysis systems with an operating pressure within the range of 1.1-2.5Mpa to improve urea production capacity, specifically a stripping-hydrolysis single tower process, the gas phase from the top of the stripping-hydrolysis tower is directly introduced into the decomposition tower (distillation tower) of the medium and low pressure system, and the heat of the gas phase of the stripping-hydrolysis tower is recovered to the maximum extent, and the excess water is limited to the medium and low pressure The system makes the ratio of water and carbon entering the urea synthesis tower controllable, thereby increasing the CO in urea synthesis 2 conversion rate, increase urea production, reduce the production energy consumption per unit of urea, making it lower than the design value

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