Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for purifying and refining epsi-caprolactam

A technology of caprolactam and refining method, which is applied in the field of purification and refining of ε-caprolactam, and can solve the problems of reduced reaction efficiency and lower absorption value of potassium permanganate

Active Publication Date: 2012-01-25
CHINA PETROLEUM & CHEM CORP +1
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Excessive hydrogenation will reduce the reaction efficiency and reduce the absorption value of potassium permanganate

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] The gas-phase Beckmann rearrangement reaction of cyclohexanone oxime was carried out in an 80ml fixed-bed reaction device. The inner diameter of the reactor was 28mm, and the molecular sieve catalyst with a high silicon-aluminum ratio MFI structure was loaded with 9.45g (Φ1.8mm strip catalyst). Pressure 0.1MPa, catalyst bed reaction temperature 365°C-385°C, carrier gas flow rate 3.0L / gcat / hr, cyclohexanone oxime WHSV 2h -1 , The partial pressure range of the mixed material: cyclohexanone oxime 5.5kPa-11.6kPa, methanol (solvent) 36.9kPa-70.6kPa, nitrogen (carrier gas) 19.4kPa-52.6kPa. The reaction product was collected by circulating and cooling the ethylene glycol solution at -5°C to obtain a reaction product containing ε-caprolactam.

[0036] First, the reaction mixture is distilled by simple distillation to remove methanol, low-boiling impurities and high-boiling impurities, and finally obtain crude ε-caprolactam. On the 6890 type gas chromatograph of Agilent Company...

Embodiment 2

[0040] As described in Example 1, take 2.0Kg of the crude ε-caprolactam obtained by the above simple distillation method, put it into a 10L reactor, add 2.0Kg of isopropyl ether, heat to 60-70°C, and stir for 30 minutes to make ε-caprolactam Caprolactam is completely dissolved in this solvent. Continue cooling while stirring, the temperature is cooled from 70°C to about 15°C, and ε-caprolactam crystals are completely precipitated. After centrifugation, 1.94Kg99.92%ε-caprolactam crystals and 2.05Kg95.8%ether were obtained. Ether solvent is recovered. 1.94Kg ε-caprolactam crystals were returned to the 10L reactor, 1.94Kg n-heptane was added, stirred and washed at room temperature for 30 minutes, and then centrifuged to obtain 99.95% ε-caprolactam crystals and 98.8% n-heptane (otherwise included 1.00% ε-caprolactam). n-heptane solvent for recovery. The obtained ε-caprolactam has a PM value of 126s and an E value of <0.6.

[0041] Hydrogenation reaction: Take 99.95% ε-caprola...

Embodiment 3

[0043] As described in Example 1, the ε-caprolactam crystals obtained by using isopropyl ether as the crystallization solvent and washing solvent were subjected to hydrogenation reaction, and the hydrogenation reaction was as follows.

[0044] Hydrogenation reaction: take 99.96% ε-caprolactam crystals washed once with 2.1Kg isopropyl ether, add them to a 5L reaction kettle, add 210g SRNA-4 industrial grade amorphous nickel hydrogenation catalyst, heat to about 90°C, Pass in hydrogen, the flow rate of hydrogen is controlled at 0.6 L / min, the reaction pressure is maintained at 5 atm, the ε-caprolactam in molten state is contacted with hydrogen, and reacted for 1 hour. Afterwards, the reaction product was distilled under reduced pressure at about 1 mmHg to obtain 2.06 Kg ε-caprolactam with a yield of 98%. The quality of the obtained ε-caprolactam product was analyzed, the PM value was 32000s, and the E value was <0.05.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
boiling pointaaaaaaaaaa
boiling pointaaaaaaaaaa
purityaaaaaaaaaa
Login to View More

Abstract

This invention relates to a refine means of epsilon - caprolactam by separation and purification. The feature of the invention is that it includes the step of crystallize epsilon - caprolactam from ethereal solution containing crude epsilon - caprolactam. The product purity can reach 99.98%upwards, absorption value of potassium permanganate is greater than 10000 or more, the extinction value of epsilon - caprolactam at 290nm wavelength is 0.05 or smaller. The invention wholly meets the require of industrial product.

Description

technical field [0001] The present invention relates to a production method of ε-caprolactam, more specifically, the present invention relates to a method of separating, purifying and refining 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 production method of caprolactam is to use oleum as a catalyst and solvent, and cyclohexanone oxime undergoes a liquid-phase Beckmann rearrangement reaction. This process has the disadvantages of corroding equipment, polluting the environment, and unsatisfactory economic benefits, and a large amount of ammonium sulfate is produced as a by-product. [0003] The gas-phase Beckmann rearrangement reaction of cyclohexanone oxime on solid acid catalyst is a new process to realize the sulfur-free ammonification of ε-caprolactam. It has no problems s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07D201/16C07D201/04
Inventor 程时标孙斌王恩泉杨克勇张树忠吴巍闵恩泽
Owner CHINA PETROLEUM & CHEM CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com