Recycling method of byproduct saline during preparation of hydrazine hydrate by using urea method

A technology for recycling and processing hydrazine hydrate, which is applied in the preparation of carbonate preparations, alkali metal chlorides, and bicarbonate salts, and can solve the problem of soil salinization, waste of space and resources, and unavailability of sodium chloride and sodium sulfate. and other problems to achieve the effect of improving purity and yield

Inactive Publication Date: 2012-11-14
HANGZHOU HI TECH FINE CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This leads to a large amount of sodium chloride and sodium sulfate in the solution not being utilized. If this is the case for a long time, it will inevitably lead to saline-alkali land in the local soil, wasting space and resources

Method used

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  • Recycling method of byproduct saline during preparation of hydrazine hydrate by using urea method
  • Recycling method of byproduct saline during preparation of hydrazine hydrate by using urea method

Examples

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Effect test

Embodiment 1

[0025] Get 500g of crude hydrazine solution, after testing, it contains hydrazine hydrate 50g / L, sodium chloride 220g / L, sodium carbonate 150g / L, sodium hydroxide 15g / L. Put the crude hydrazine solution into a 1L reactor, and feed carbon dioxide gas into the reactor, adjust the negative pressure of the steel cylinder containing carbon dioxide gas to 100pa, and the flow rate to be 0.8mol / L. When the negative pressure of the steel cylinder containing carbon dioxide gas is 0 , continue stirring for 0.5h. Afterwards, freeze and crystallize by circulating frozen brine, keep the temperature at 6 ° C, freeze for 2 hours, filter cold, and put the filter residue into a 35 ° C vacuum oven for drying for 4 hours. Add urea to the filtrate, add sulfuric acid to adjust the pH to 3, stir for 2 hours under the condition of controlling the temperature to be 106° C., filter to obtain biurea, and pass chlorine gas oxidation to obtain ADC foaming agent in the reactor of biurea, wherein after the ...

Embodiment 2

[0027] Get 500g thick hydrazine solution, after testing, composition is the same as above, add thick hydrazine solution in 1L reactor, and pass into carbon dioxide gas in the reactor, adjust the steel cylinder negative pressure that carbon dioxide gas is housed to be 150pa, flow rate 0.5mol / L, When the negative pressure of the steel cylinder containing carbon dioxide gas is 0, continue stirring for 0.5h. Afterwards, freeze and crystallize by circulating frozen brine, keep the temperature at 2 ° C, freeze for 2 hours, filter cold, and put the filter residue into a 45 ° C vacuum oven for drying for 4 hours. Add urea to the filtrate, add sulfuric acid to adjust the pH to 4, stir for 2 hours under the condition of controlling the temperature at 120 ° C, filter to obtain biurea, and pass chlorine gas oxidation to obtain ADC foaming agent in the biurea reaction kettle, wherein the obtained after the reaction The filtrate is sent to the electrolytic cell. The calculation shows that ...

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Abstract

The invention discloses a recycling method of a byproduct saline during preparation of hydrazine hydrate by using a urea method. The method includes adding excess CO2 into a coarse hydrazine solution, and keeping the negative pressure of a steel cylinder containing the CO2 to be 100pa to 150pa and the flow to be 0.5-0.8mol/L; stirring the mixture continuously for 0.5 hour when the negative pressure in the steel cylinder is zero; freezing and crystallizing the solution through general freezing brine, and controlling the temperature in a range from 2 DEG C to 6 DEG C and the freezing time to be 2 hours; performing cold filtering to obtain filter residues, drying the filter residues in a vacuum drying oven for 4 hours, and keeping the temperature of the drying oven to be 35 DEG C to 45 DEG C; adding urea into the filtrate obtained through cold filtering, adding sulfuric acids to regulate the pH to be 3 to 4, controlling the temperature to be 106 DEG C to 120 DEG C, and reacting the mixture for 2 hours; and feeding chlorine into a biurea reaction still to perform oxidation to obtain the resultant ADC foaming agents, wherein the filtrate is sent to an electrolytic tank. The recycling method of byproduct saline during preparation of hydrazine hydrate by using the urea method has the advantages that the byproduct sodium salt of the hydrazine hydrate is fully recycled, the cost is reduced, and the method is a green chemical process.

Description

technical field [0001] The invention relates to a treatment method for by-products in the production of hydrazine hydrate by the urea method, more specifically, sodium chloride, sodium carbonate and sodium hydroxide, etc. Salinity recovery treatment method. Background technique [0002] Hydrazine hydrate, also known as hydrazine hydrate, is the monohydrate of hydrazine (N 2 h 4 ·H 2 O), the appearance is a colorless transparent liquid, which can be mixed with water and alcohol arbitrarily, and is insoluble in ether and chloroform. Hydrazine hydrate is an important fine chemical intermediate, which is widely used in the synthesis of pesticides, medicines, water treatment, foaming agents, initiators and curing agents, etc., and has broad prospects for development and utilization. [0003] The production methods of hydrazine hydrate include Raschig method, urea method, ketazine method, hydrogen peroxide method and air oxidation method. [0004] The urea method to produce h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C281/20C01D7/10C01D7/07C01D3/04
Inventor 董梅陈海贤
Owner HANGZHOU HI TECH FINE CHEM
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