Production process of synergistic urea

Abstract

The invention relates to a production process of synergistic urea. The production process comprises the following steps: leading branch urine out of a main pipeline of urine with mass concentration of95% after primary evaporation or a main pipeline of urine with mass concentration of 99.5% after secondary evaporation; mixing and dissolving the branch urine with a synergist and a defoamer uniformly to obtain a synergistic solution; sending the synergistic solution back to a main pipeline between an evaporator and a granulation system, and then entering a granulation step of the granulation system. The production process has the following advantages: (1) transferring from ordinary urea to the synergistic urea is more flexible and rapid; (2) fewer transition products are produced during transferring; (3) after transferring, the normal operation of a main unit of the ordinary urea is hardly affected; (4) the mass ratio of the amount of the branch urine taken out from the main pipeline tothe amount of urine of the main pipeline is 1:(5-50), and the influence on biuret content of a synergistic urea product is smaller.

Description

technical field [0001] The invention relates to a production process of synergistic urea, belonging to the technical field of fertilizer production. Background technique [0002] Urea has the advantages of high nitrogen content, stable performance, and easy storage. It is the main type of nitrogen fertilizer at present. Urea can be widely used as topdressing fertilizer for field crops and fruit and vegetable crops, such as spreading of wheat, corn, cotton, rice, fruit trees, etc. Blowing application; convenient and extensive application. According to public information, in 2016, the demand for agricultural urea in my country was about 41.5 million tons, the demand for industrial urea was about 16.5 million tons, and the demand for urea for export was about 9 million tons. However, according to public information, the current utilization rate of ordinary urea in my country is only about 30%, significantly lower than the level of 50-60% in developed countries. The urea nitro...

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Problems solved by technology

[0009] (1) The synergist is added to the molten urea in the form of an aqueous solution. Due to the introduction of a large amount of water, the production load of the evaporator and the granulator will be increased, the energy consumption will be increased, and the production cost will be increased.

[0010] (2) Add the synergist directly into the urine storage tank in front of the evaporator in the form of powdery solid or add the synergist in the form of an aqueous solution between the first-stage evaporation and the second-stage evaporation, because the condensate of the evaporator contains The synergist component, after returning to the original system, will pollute the original system, thereby increasing the system replacement time and producing a large number of transition products; in addition, the condensate returned to the original system will increase the viscosity of the material due to the synergist component. Large, it is easy to affect the fluidity of the material, thereby increasing the system resistance; the sewage discharged from the system contains synergists, which will exceed the national discharge standard and increase the pressure on environmental protection

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