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A kind of refining process of caprolactam

A caprolactam and process technology, which is applied in the field of refining processes for the separation and purification of ε-caprolactam, can solve the problems that the regeneration of the spare resin has not been completed, the quality of the disengaged material is reduced, and the impurity content is increased, so as to reduce the operating cost and labor intensity, reduce the content, the effect of prolonging life

Inactive Publication Date: 2017-12-01
JIANGSU SANDING PETROCHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Under normal circumstances, a set of ion exchange resin needs to be regenerated after running for about 7 days, and as the production load increases, or the impurity content increases, the quality of the handover output decreases, and the regeneration cycle will be shortened to about 4 days, and even spare resins will appear. The regeneration has not been completed, and the ion exchange resin can no longer meet the production requirements
In the regeneration process of the ion exchange resin, a large amount of desalted water, nitric acid, and sodium hydroxide are consumed as regenerants, and a large amount of waste water is generated. Therefore, the ion exchange process in the prior art has been limited by the short regeneration cycle, high regenerant consumption, and large waste water discharge. troubled

Method used

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  • A kind of refining process of caprolactam
  • A kind of refining process of caprolactam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] The Beckmann rearrangement reaction of cyclohexanone oxime (purity 99.95%) and nicotinic acid is followed by neutralization and benzene extraction to obtain benzene ethyl alcohol. Styrene liquid index: conductivity: 83μs / cm, extinction value: 1.04. The benzene ethyl alcohol a from benzene extraction is drawn from the benzene ethyl alcohol storage tank 21, and is sent in the coalescer 23 after the first feed pump 22 mixes with the lye in the pump body of the first feed pump 22, and the lye is 42% Mass concentration sodium hydroxide solution, the add-on is 2g / kg benzene ethyl alcohol liquid, in coalescer 23, fill coalescing packing, packing type is ceramic moment saddle ring (Intalox), sampling analysis at coalescer 23 upper discharge port, At this time, the conductivity of the benzene ethyl alcohol solution was 28 μs / cm. The water phase (bottom liquid d) obtained by condensing in the coalescer 23 is drawn from the bottom, and sent to the styrene-hexane liquid storage ta...

Embodiment 2

[0039] Perform Beckmann rearrangement of cyclohexanone oxime (purity 99.95%) and nicotinic acid, and then neutralize and extract with benzene to obtain benzene ethyl alcohol. Styrene liquid index: conductivity: 107μs / cm, extinction value is 1.27. The benzene ethyl alcohol a from the benzene extraction is drawn from the benzene ethyl alcohol storage tank 21, through the first feed pump 22, mixed with the introduced lye in the static mixer 26 on the inlet line of the first feed pump 22, and sent to the coalescing In the device 23, the lye is a 30% mass concentration sodium hydroxide solution, and the addition amount is 3.5g / kg benzene ethyl alcohol, and the coalescing packing is filled in the coalescing device 23, and the packing type is a ceramic saddle ring (Intalox). Sampling and analysis at the discharge port on the upper part of the knotter 23, at this time, the conductivity of the benzene ethyl alcohol solution was 25 μs / cm. The water phase obtained by condensing in the c...

Embodiment 3

[0041] Perform Beckmann rearrangement of cyclohexanone oxime (purity 99.95%) and nicotinic acid, and then neutralize and extract with benzene to obtain benzene ethyl alcohol. Styrene liquid index: conductivity: 95μs / cm, extinction value is 1.13. The benzene ethyl alcohol a from benzene extraction is drawn from the lower part of the benzene ethyl alcohol storage tank 21, and is sent in the coalescer 23 after being mixed with the lye in the first feed pump 22 by the first feed pump 22, and the lye is 20% mass concentration Sodium hydroxide solution, the addition amount is 9g / kg benzene ethyl alcohol liquid, the liquid-liquid coalescing filter element of caustic alkali used in packing and separating hydrocarbons in the coalescer 23, LCS2H1AH, operating temperature 45 ℃, pressure is normal pressure, in the coalescing Sampling analysis was carried out at the discharge port on the upper part of the device. At this time, the conductivity of the benzene ethyl alcohol solution was 28 μ...

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Abstract

The invention discloses a caprolactam refining technology comprising steps as follows: before an ion exchange procedure, performing alkaline washing, dehydration and water extraction procedures on benzene caproate solution obtained after benzene extraction. Compared with the prior art, the caprolactam refining technology has the advantages that before the water extraction procedure, two times of desalted water washing technologies are changed into alkaline washing and water washing technologies, so that the content of ammonium sulfate in a fed liquid is decreased, meanwhile, the content of organic impurities is decreased, the running load in the follow-up ion exchange procedure is reduced, the service life of ion exchange resin is prolonged, the reoperation frequency is reduced, the running cost and the labor intensity are reduced, and the product quality is improved.

Description

technical field [0001] The invention belongs to the field of ε-caprolactam production, and in particular relates to a refining process for the separation and purification of ε-caprolactam. Background technique [0002] ε-caprolactam is one of the important raw materials for synthetic fibers and synthetic resins, mainly used in the manufacture of polyamide fibers (nylon 6), resins and films. At present, the industrial method for producing caprolactam from cyclohexanone oxime is to use oleum and cyclohexanone oxime to undergo a liquid-phase Beckmann rearrangement reaction, and the rearrangement product needs to be separated, purified and refined through the following procedures: neutralization, benzene extraction, Washing with benzene, water extraction, ion exchange, hydrogenation, evaporation, distillation, etc. There are many separation and purification procedures for rearrangement reaction products, which are caused by the existence of inorganic salt ammonium sulfate and i...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D223/10C07D201/16
CPCC07D201/16C07D223/10
Inventor 卢世健徐鹏张立娇
Owner JIANGSU SANDING PETROCHEM TECH