Purification process for caprolactam

A technology of caprolactam and crude caprolactam, which is applied in the field of refining process of caprolactam, can solve the problems of high processing cost, easily polluted anion exchange resin, resin utilization rate and low resin utilization rate, and achieves reduction of pollution, size reduction and regeneration cycle. the effect of shortening

Active Publication Date: 2014-12-10
河北美邦工程科技股份有限公司 +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a refining process for caprolactam, which solves the problem of low resin utilization and high processing cost in the caprolactam crude product refining process by converting cyclohexanone into cyclohexanone oxime and then rearranging into caprolactam
In order to solve the problems of the traditional fixed bed ion exchange system, the anion exchange resin is easily polluted, the resin utilization rate is low, and the processing cost is high. ion exchange system

Method used

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  • Purification process for caprolactam
  • Purification process for caprolactam
  • Purification process for caprolactam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) Cool the crude caprolactam aqueous solution flowing out from the extraction process to 43°C;

[0027] (2) Pass the cooled crude caprolactam aqueous solution through an ion exchange system composed of a fixed bed chromatography resin device and a fixed bed ion exchange device in series to remove the NH 4 + , SO 4 2- and other trace ions and some organic impurities, the extinction value of the obtained crude caprolactam aqueous solution at 290 nm is stable at about 0.1, which improves the purity of the crude caprolactam aqueous solution. Both the chromatography resin device and the ion exchange resin device are composed of 30 resin columns of the same specification. The filler in the resin column of the chromatography resin device is D101 type macroporous adsorption resin;

[0028] (3) In the ion exchange system, the methanol solution with a mass fraction of 90% is used to regenerate the saturated chromatographic resin; the sodium hydroxide solution with a mass fr...

Embodiment 2

[0033] (1) Cool the crude caprolactam aqueous solution flowing out from the extraction process to 44°C;

[0034] (2) Pass the cooled crude caprolactam aqueous solution through an ion exchange system composed of a fixed bed chromatography resin device and a fixed bed ion exchange device in series to remove the NH 4 + , SO 4 2- and other trace ions and some organic impurities, the extinction value of the obtained crude caprolactam aqueous solution at 290 nm is stable at about 0.1, which improves the purity of the crude caprolactam aqueous solution. Both the chromatography resin device and the ion exchange resin device are composed of 30 resin columns of the same specification. The filler in the resin column of the chromatography resin device is D-101-I macroporous adsorption resin;

[0035] (3) In the ion exchange system, a solution with a mass fraction of methanol of 90% and a mass fraction of hydrochloric acid of 4% was used as the eluent to regenerate the saturated chroma...

Embodiment 3

[0040] (1) Cool the crude caprolactam aqueous solution flowing out from the extraction process to 45°C;

[0041] (2) Pass the cooled crude caprolactam aqueous solution through an ion exchange system composed of a fixed bed chromatography resin device and a fixed bed ion exchange device in series to remove the NH 4 + , SO 4 2- and other trace ions and some organic impurities, the extinction value of the obtained crude caprolactam aqueous solution at 290 nm is stable at about 0.1, which improves the purity of the crude caprolactam aqueous solution. Both the chromatography resin device and the ion exchange resin device are composed of 30 resin columns of the same specification. The filler in the resin column of the chromatography resin device is DA-201 type macroporous adsorption resin;

[0042] (3) In the ion exchange system, use a solution with a mass fraction of ethanol of 90% and a mass fraction of sodium hydroxide of 5% as an eluent to regenerate the saturated chromatogr...

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Abstract

The invention discloses a purification process for caprolactam. The purification process comprises the following steps: cooling crude caprolactam aqueous liquor obtained in an extracting process to 43-45 DEG C; then, passing the cooled crude caprolactam aqueous liquor through an ion exchange system which is composed of a chromatography resin device and an ion exchange device; and carrying out hydrogenation, evaporation and distillation to prepare a caprolactam finished product. The chromatography resin device is introduced to the ion exchange system, so that the problem that anion exchange resin is easy to pollute and difficult to regenerate is solved. The resin impurity removal and the resin regeneration are realized by continuously moving the bed-layer chromatography resin device and bed ion exchange resin, the regeneration period of the resin is shortened, and the stability of the discharge purity of the caprolactam aqueous liquor in an ion exchange process is guaranteed. Moreover, the number of resin columns is increased and the size of the resin columns is reduced, so that the total filling amount in the continuous ion exchange system is reduced, and the dosage of acid and alkaline in the regenerating process is also correspondingly reduced, and thus, the cost is saved and the secondary pollution is lowered.

Description

technical field [0001] The invention relates to a refining process of caprolactam, which is particularly suitable for the refining process of caprolactam prepared by ammonia oximation, and belongs to the technical field of organic chemical raw material production. Background technique [0002] Caprolactam is an important chemical raw material for synthetic fibers and engineering plastics. When it is used as a polymeric raw material for the production of nylon-6, its quality requirements are very strict. In the prior art, most manufacturers adopt the production route of converting cyclohexanone into cyclohexanone oxime, and then converting into caprolactam through rearrangement. Because the production process of caprolactam is complicated, often contain trace amount of ammonium sulfate and 2-methylcyclopentanol, cyclohexanone, aniline, N-ethyl-N(1-methylethyl)-2-propylamine, Organic impurities such as 3-methylcyclohexanone oxime, although the content of these impurities is l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D201/16C07D223/10
CPCC07D201/16
Inventor 张玉新宛捍东吕志金作宏高文杲张卫国张志学
Owner 河北美邦工程科技股份有限公司
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