Method of preparing azodiisobutyronitrile

A technology of azobisisobutyronitrile and diisobutyronitrile hydrazine, which is applied in the field of preparing azobisisobutyronitrile, can solve problems such as environmental pollution, achieve the effects of simplifying production procedures, reducing production costs, and solving environmental pollution

Inactive Publication Date: 2014-07-02
唐山晨虹实业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In fact, most manufacturers of azobisisobutyronitrile use low-grade soda ash, caustic soda or lime to neutralize the by-product hydrochloric acid, and discharge it after reaching PH=6-9, causing pollution to the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0009] (1) Preparation of a refined solution of hydrazine hydrate

[0010] Prepare 22-26% caustic soda solution by adding water to 32% liquid caustic soda, react with chlorine to generate sodium hypochlorite; add water to solid urea and catalyst to prepare saturated urea solution, react with sodium hypochlorite obtained in the previous step to obtain a crude solution containing hydrazine hydrate. The crude solution of hydrazine hydrate contains hydrazine hydrate, sodium chloride, sodium hydroxide and sodium carbonate, wherein the two compounds of sodium hydroxide and sodium carbonate cannot be used in the flow process for producing azobisisobutyronitrile. Because sodium hydroxide is strongly alkaline and sodium carbonate is weakly alkaline, both of them have a serious impact on the synthesis of diisobutyronitrile with hydrazine hydrate and acetone cyanohydrin, while sodium chloride has a strong impact on the synthesis of diisobutyronitrile Hydrazine had no effect.

[0011] (...

Embodiment

[0020] (1) Prepare 25% caustic soda solution by adding water to 32% liquid caustic soda, and introduce chlorine to react to generate sodium hypochlorite. Use frozen brine or water to lower the temperature and control the reaction temperature to be less than 25°C, so that the sodium hypochlorite solution contains 130-135 grams per liter of available chlorine and 150-150 grams per liter of sodium hydroxide. Add solid urea and catalyst into water to prepare a saturated urea solution. Mix the urea solution with sodium hypochlorite and heat to 110°C to react to obtain a crude solution containing hydrazine hydrate. Cool the crude solution to -10°C~-15°C with frozen brine, and keep the solution as low as possible. The sodium carbonate in the solution becomes sodium carbonate decahydrate and precipitates out, and the sodium carbonate decahydrate is separated by centrifugation to obtain a refined solution containing hydrazine hydrate. Lift.

[0021] (2) Treatment of refined solution o...

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PUM

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Abstract

The invention relates to a method of preparing azodiisobutyronitrile. The method comprises the following steps: a, carrying out a reaction on acetone cyanohydrin and hydrazine hydrate to generate diisobutyronitrile hydrazine; and b, introducing chlorine to diisobutyronitrile hydrazine to react to generate azodiisobutyronitrile, wherein hydrazine hydrate used in the step a is prepared by a urea method. The hydrazine hydrate is specifically prepared by the following steps: (1) introducing chlorine to a caustic soda solution to generate sodium hypochlorite; (2) adding solid urea to prepare a urea saturated solution and carrying out a reaction with sodium hypochlorite to obtain a coarse solution containing hydrazine hydrate; and (3) freezing and crystallizing the coarse solution containing hydrazine hydrate to separate sodium carbonate decahydrate so as to obtain a refined solution of hydrazine hydrate, adding a neutralizer to neutralize the pH to 2-3, removing sodium hydroxide and sodium carbonate in the solution, and then adding the refined solution of hydrazine hydrate to reversely neutralize to PH to 10-10.5. According to the method provided by the invention, the purification process of the hydrazine hydrate solution is canceled and the production procedure is simplified, so that the production cost is greatly lowered.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a method for preparing azobisisobutyronitrile. Background technique [0002] The conventional method for preparing azobisisobutyronitrile is to put the metered acetone cyanohydrin into a synthesis kettle, add water at a ratio of 1:1, and add the diluted hydrazine hydrate solution dropwise in proportion to react under stirring to obtain diisobutyl Nitrile hydrazine, through chlorine gas for oxidation reaction to obtain azobisisobutyronitrile, wherein the hydrazine hydrate solution can be prepared by urea method. [0003] The urea method is used to prepare hydrazine hydrate by using liquid caustic soda, urea, and chlorine as raw materials. Sodium hypochlorite is generated through the reaction of liquid caustic soda and chlorine. The urea and catalyst are added with water to prepare a saturated solution and react with sodium hypochlorite to obtain a crude solution containing hydrazi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C255/65C07C253/30
Inventor 郑廷来付永宽孟宪全
Owner 唐山晨虹实业有限公司
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