Energy-saving ammonia water distillation technology

Abstract

The invention provides an energy-saving ammonia water distillation production method which comprises the following steps: (a) providing raw material ammonia water containing NH3 and impurities generated in the production process of chemical enterprises, wherein the impurities comprise H2S, HCN and / or CO2 impurities; (b) performing heat exchange between high-temperature wastewater at the bottom of a distillation tower and the raw material ammonia water and allowing the high-temperature wastewater to enter an evaporator or directly allowing the high-temperature wastewater to enter the evaporator, and performing partial flashing to generate first low-entropy steam, so that the temperature is reduced to be 55-125 DEG C; (c) circulating and feeding the low-temperature wastewater in the evaporator into a dephlegmator, heating the low-temperature wastewater to the temperature of 70-130 DEG C by ammonia steam, returning the wastewater back to the evaporator, and performing partial flashing to generate second low-entropy steam; (d) compressing the obtained first low-entropy steam and second low-entropy steam in the evaporator into saturated high-entropy steam at the temperature of 103-165 DEG C by an MVR (Mechanical Vapor Recompression) compressor, and feeding the saturated high-entropy steam into the distillation tower to serve as a heat supply source for distillation.

Description

technical field [0001] The invention relates to a method for processing raw ammonia water by adopting distillation, evaporation and MVR compression integrated process, especially suitable for the NH-containing NH 3 and H 2 S and HCN, CO 2 Ammonia treatment of raw materials such as impurities. Background technique [0002] According to C (carbon), H (hydrogen), S (sulfur), N (nitrogen), O 2 (Oxygen) and other components are different and the selection of processing technology generates NH in the production process 3 and H 2 S and HCN, CO 2 and other impurities, these impurities are dissolved in water to form raw ammonia water. Although the raw ammonia water itself has little practical value and the cost of treatment is high, the strict requirements of environmental protection do not allow its direct discharge. [0003] In order to solve the outlet of the raw ammonia water, the NH in the raw ammonia water is generally distilled 3 and H 2 S and HCN are separated and re...

AI Technical Summary

Problems solved by technology

[0007] And the place that conventional ammonia water distillation process needs to improve is, the one, need heat source such as a large amount of fresh steams to provide heat for distillation; The 2nd, use a large amount of cooling water to shrink ( Partial condensation cooling, the same below) operation, the phase change heat of water vapor in ammonia vapor has not been properly recovered and utilized, resulting in high external heat supply and high energy consumption required by the process

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