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Improved technology of mono-methyl hydrazine production process

A technology for the production of monomethylhydrazine, applied in the preparation of hydrazine, organic chemistry, etc., can solve the problems of many by-products and low reaction yield, and achieve the effects of increasing yield, simple process, and reducing costs

Inactive Publication Date: 2020-06-23
DONGLI NANTONG CHEM +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] The purpose of the present invention is to provide a kind of improved process technology on the basis of the hydrochloric acid methanol hydrazine hydrate process technology to solve the shortcomings of many by-products and low reaction yields when synthesizing monomethylhydrazine with the hydrochloric acid methanol hydrazine hydrate process at present, and prevent the rapid reaction in the reaction solution. The environmental pollution caused by the formation of toxic polyhydric hydrazines, the purpose of increasing the yield and reducing the cost, invented a kind of redox control to the reaction mixture realized by using methyl chloride as a catalyst in the reaction of hydrochloric acid methanol hydrazine hydrate The single formation of monomethylhydrazine (MMH) has high selectivity and prevents the recovery of polyhydrazine compound by-products, and a new process for the clean production of the target product-methylhydrazine has been established.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Slowly add 125g (2.0mol) of 80% hydrazine hydrate dropwise to 192.1g (2.0mol) of 38% concentrated hydrochloric acid, control the temperature at 20-30°C for 2 hours under stirring conditions, and adjust the pH to 6-7 after the reaction is complete In the meantime, vacuum distilled off water, mixed the obtained hydrazine hydrochloride with 96 g (3 mol) of methanol, raised the reaction temperature to 85° C. and condensed and refluxed for 2-3 h. The mixed solution after the reaction is distilled to separate methanol and a small amount of water, and the methanol can be recycled. The remaining raffinate is added into 136.0g of hydrazine hydrate with a mass fraction of 80% to be free, and the liquid reaction mixture is analyzed to obtain the following results: selectivity methylhydrazine: 94.0%; selectivity 1,1-dimethylhydrazine Hydrazine: 3.7%; selectivity to 1,2-dimethylhydrazine rate: 2.1%; selectivity to 1,1,1-trimethylhydrazine rate: 0.3%. Finally, the dissociated soluti...

Embodiment 2

[0030] Slowly add 125g (2.0mol) of 80% hydrazine hydrate dropwise to 192.1g (2.0mol) of 38% concentrated hydrochloric acid, control the temperature at 20-30°C for 2 hours under stirring conditions, and adjust the pH to 6-7 after the reaction is complete In between, vacuum distilled off the water, mixed the obtained hydrazine hydrochloride with 96g (3mol) of methanol, raised the reaction temperature to 85°C and condensed and refluxed for a period of time, slowly introduced methylene chloride into the mixed solution to react for 2-3h . The mixed solution after the reaction is distilled to separate methanol and a small amount of water, and the methanol can be recycled. The remaining raffinate was added into 136.0g of hydrazine hydrate with a mass fraction of 80% to be free, and the liquid reaction mixture was analyzed to obtain the following results: selectivity methylhydrazine: 96.0%; selectivity 1,1-dimethylhydrazine Hydrazine: 1.3%; selective 1,2-dimethylhydrazine: 0.8%; sele...

Embodiment 3

[0032] Slowly add 125g (2.0mol) of 80% hydrazine hydrate dropwise to 192.1g (2.0mol) of 38% concentrated hydrochloric acid, control the temperature at 20-30°C for 2 hours under stirring conditions, and adjust the pH to 6-7 after the reaction is complete In between, vacuum distilled off the water, mixed the obtained hydrazine hydrochloride with 96g (3mol) of methanol, raised the reaction temperature to 85°C and condensed and refluxed for a period of time, slowly introduced methylene chloride into the mixed solution to react for 2-3h . Distribute the reaction mixture into the mixed solution of sulfuric acid and sodium percarbonate and stir, and add CaO to the obtained compound salt at a reaction temperature of 60°C for 1 hour to resolve, finely filter, add a small amount of sodium sulfite to the filtrate, and then mix the solution at 50°C for 15 minutes. The liquid reaction mixture was analyzed to give the following results: Selectivity to methylhydrazine: 99.9%; Selectivity to ...

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Abstract

The invention discloses an improved technology of a mono-methyl hydrazine production process. An improved process is invented on the basis of a hydrochloric acid methanol hydrazine hydrate method, andthe defects of many byproducts, low reaction yield, environmental pollution caused by formation of highly toxic polybasic hydrazine in a reaction solution, and the like, when mono-methyl hydrazine issynthesized by using a hydrochloric acid methanol hydrazine hydrate method at present are overcome. According to the method, further methyl diversification of the target product mono-methyl hydrazinegenerated firstly in the reaction process is avoided, single production of the target product is guaranteed, more importantly, the process is simplified and environmentally friendly, the yield is increased, and the cost is reduced.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a new process technology for improving the synthesis process of industrial production of monomethylhydrazine and establishing the clean production of target products Background technique [0002] Monomethylhydrazine is widely used in medicine, pesticides and dyes. Because of its low freezing point, good thermal stability and stable combustion process, it is considered a very valuable compound in various industries such as aerospace and missiles. With the development of the market There is a large demand for this raw material, and the production volume is also increasing. my country is also a big producer of monomethylhydrazine, and its annual output ranks among the top in the world. [0003] There are many reports on the synthetic method of methylhydrazine, currently according to the existing literature synthetic method mainly contains the following: [0004] Chloramine method ...

Claims

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Application Information

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IPC IPC(8): C07C241/02C07C243/14
CPCC07C241/02C07C243/14
Inventor 阿依别克·马力克衣伟男周建
Owner DONGLI NANTONG CHEM
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