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Method for preparing hexamethylenediamine

A technology of hexamethylenediamine and caprolactam, which is applied in the chemical industry, can solve the problems of dependence on imports, no valuable components in waste liquid, and few reports, and achieve the effect of high purity

Pending Publication Date: 2022-03-08
昌德新材科技股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these two traditional treatment methods have disadvantages such as high energy consumption, high operating costs, high ammonia content in the discharged wastewater, and no recycling of valuable components in the waste liquid.
[0003] Hexamethylenediamine is an important chemical raw material, which is often used to synthesize important industrial products such as nylon 66, nylon 610, HDI, etc. However, there is no production device for the synthesis of hexamethylenediamine adiponitrile in my country, and it is completely dependent on imports. , so it is very important to develop new synthetic methods of hexamethylenediamine
Synthesis of hexamethylenediamine from caprolactam waste liquid, very few reports

Method used

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  • Method for preparing hexamethylenediamine
  • Method for preparing hexamethylenediamine
  • Method for preparing hexamethylenediamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] Take 200g of caprolactam waste liquid, add 35g of acetic acid and carry out reflux reaction at 110°C for 8 hours to obtain the first product; then dehydrate the first product under reduced pressure to a water content of 2%, add 160g of ethanol to dissolve it, and filter out inorganic salts such as ammonium sulfate , to obtain the second product; add 50g cyclohexane to the second product as a water-carrying agent, carry out esterification at 110°C, and when anhydrous continues to be generated, heat up to 150°C to evaporate excess ethanol and cyclohexane As a recycled solvent, a third product is obtained. Slowly add 2g of phosphorus oxychloride and 100g of liquid ammonia to the third product, heat to 110°C for ammonolysis reaction for 5 hours, then rectify and purify 30g of aminocapronitrile, and use Raney nickel as a catalyst at 300°C for hydrogenation 25 g of hexamethylenediamine were prepared.

Embodiment 2

[0061] Take 500g of caprolactam waste liquid, add 100g of phosphoric acid and carry out reflux reaction at 120°C for 10 hours to obtain the first product; then dehydrate the first product under reduced pressure to a water content of 5%, add 800g of ethylene glycol to dissolve it, filter out ammonium sulfate, etc. Inorganic salt to obtain the second product; add 90g cyclohexane to the second product as a water-carrying agent, and carry out esterification at 100°C. When anhydrous continues to form, heat up to 200°C to evaporate excess ethylene glycol and Cyclohexane was used as a recycle solvent to obtain the third product. Slowly add 25g of phosphorus pentoxide and 200g of formamide to the third product, heat to 150°C for ammonolysis reaction for 5h, then rectify and purify 100g of aminocapronitrile, use Pd / C compound as catalyst at 180°C, add Hydrogen preparation yielded 90 g of hexamethylenediamine.

Embodiment 3

[0063] Take 1000g of caprolactam waste liquid, add 300g of hydrochloric acid and carry out reflux reaction at 110°C for 8 hours to obtain the first product; then dehydrate the first product under reduced pressure to a water content of 3%, add 1000g of ethanol to dissolve it, and filter out inorganic salts such as ammonium sulfate , to obtain the second product; add 100g cyclohexane to the second product as a water-carrying agent, carry out esterification at 110°C, and when anhydrous continues to form, heat up to 120°C to evaporate excess ethanol and cyclohexane As a recycled solvent, a third product is obtained. Add 10g molecular sieves and 300g ammonium oxalate to the third product, heat to 200°C for ammonolysis reaction for 6h, then rectify and purify 310g aminocapronitrile, and use nickel-copper alloy as catalyst at 350°C to prepare 268g hexanonitrile by hydrogenation diamine.

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Abstract

The invention relates to a method for preparing hexamethylenediamine, which comprises the following steps: S1, adding an acid solution into waste liquid of caprolactam prepared by a rearrangement method, and carrying out reflux reaction to obtain a first product; s2, dehydrating the first product under reduced pressure, adding the dehydrated first product into an alcohol solvent, dissolving, and filtering to obtain a second product; s3, adding a water-carrying agent into the second product, and carrying out esterification reaction to obtain a third product; s4, contacting the third product with a dehydration catalyst and an ammonia source, and performing ammonolysis reaction to obtain aminocapronitrile; s5, purifying amino-capronitrile, contacting the purified amino-capronitrile with a hydrogenation catalyst, and carrying out hydrogenation reaction to obtain hexamethylenediamine; wherein the waste liquid of caprolactam prepared by the rearrangement method is selected from at least one of waste liquid of caprolactam prepared by a sulfuric acid liquid-phase rearrangement method and waste liquid of caprolactam prepared by a sulfuric acid gas-phase rearrangement method. According to the method, valuable components are extracted and converted into a high-added-value product hexamethylenediamine while the problem of environmental pollution caused by the waste liquid is solved.

Description

technical field [0001] The disclosure relates to the field of chemical technology, in particular to a method for separating and preparing hexamethylenediamine by using the waste liquid of caprolactam produced by the rearrangement method as a raw material. Background technique [0002] At present, there are two general treatment methods for caprolactam waste liquid in industry: one is to increase the mass fraction of organic matter and salt in the waste liquid to 40%-70%, and then carry out spray combustion under the condition of about 900°C; the other is to The biochemical system is used to reduce the content of organic matter in wastewater. However, these two traditional treatment methods have disadvantages such as high energy consumption, high operating costs, high ammonia content in the discharged wastewater, and no recycling of valuable components in the waste liquid. [0003] Hexamethylenediamine is an important chemical raw material, which is often used to synthesize ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/48C07C211/12C07C253/22C07C253/20C07C255/24C07C231/02C07C237/06C07C227/22C07C227/18C07C229/08
CPCC07C209/48C07C253/22C07C253/20C07C231/02C07C227/22C07C227/18C07C229/08C07C237/06C07C255/24C07C211/12
Inventor 易伟杨浴刘文瑞杜立秋蒋卫和屈铠甲
Owner 昌德新材科技股份有限公司
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