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Method for preparing caprolactam by phase rearrangement of cyclohexanone oxime liquid

A technology for cyclohexanone oxime and caprolactam, which is applied in the field of preparing caprolactam by liquid-phase rearrangement of cyclohexanone oxime, can solve the problems such as failure to realize industrialization, difficult separation of ionic liquid and product, unfavorable product refining and downstream product production, and the like. The effect of easy separation, high selectivity and mild reaction conditions

Inactive Publication Date: 2008-08-27
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the use of ionic liquids, it is difficult to separate the ionic liquid from the product, which is not conducive to the refining of the product and the production of downstream products, so it has not been industrialized so far.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Add 20ml of water-carrying agent ethyl acetate to 20ml of perfluorotoluene solvent, reflux for dehydration, dry with anhydrous sodium sulfate for 3 times, and then dry with color-changing silica gel for 2 times. Then, 20 mmol of cyclohexanone oxime, 2 g of sulfonated activated carbon catalyst (dried in an oven at 70-90° C. for 10-14 hours before use, and then cooled in a vacuum oven for use), reacted at 120° C. for 15 hours.

[0014] The results of American Agilent6890N gas chromatographic analysis are: the conversion rate of cyclohexanone oxime is 90.7%, the selectivity of caprolactam is 90.1%, and the selectivity of by-product cyclohexanone is 9.9%.

Embodiment 2

[0016] Same as Example 1, except that 20ml of water-carrying agent toluene was added to 20ml of 1-bromoperfluorooctane solvent to reflux for dehydration, then dried with anhydrous sodium sulfate for 3 times, and then dried with color-changing silica gel for 2 times. Then, 20 mmol of cyclohexanone oxime and 2 g of sulfonated aluminum silicate catalyst (the drying process is the same as in Example 1) were reacted at 120° C. for 15 h.

[0017] The conversion rate of cyclohexanone oxime was 98.5%, the selectivity of caprolactam was 87.7%, and the selectivity of by-product cyclohexanone was 12.3%.

Embodiment 3

[0019] Same as Example 1, except that the water-carrying agent cyclohexane was added to the dimethyl sulfoxide solvent to reflux for dehydration, then dried with anhydrous sodium sulfate for 3 times, and then dried with color-changing silica gel for 2 times. Then, 20 mmol of cyclohexanone oxime and 2 g of biomass charcoal sulfonic acid catalyst (the drying process is the same as in Example 1) were reacted at 130° C. for 12 h.

[0020] The conversion rate of cyclohexanone oxime is 100%, the selectivity of caprolactam is 99.2%, and the selectivity of by-product cyclohexanone is 0.8%.

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PUM

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Abstract

A method for rearranging the liquid phase of cyclohexanone oxime to prepare caprolactam comprises dissolving cyclohexanone oxime indehydrated organic solvent, using dried solid acid as catalyst, in a liquid-solid reaction system, catalyzing cyclohexanone oxime to generate Beckmann rearrangement to prepare caprolactam. The invention has simple operation, normal pressure process, mild reaction conditions, easily separated reaction product, catalyst and solvent, completed converted cyclohexanone oxime and high selectivity of caprolactam.

Description

technical field [0001] The invention relates to a method for preparing caprolactam by liquid-phase rearrangement of cyclohexanone oxime. Background technique [0002] Caprolactam is an important monomer for the manufacture of nylon 6, plastics and films. Catalyzing the Beckmann rearrangement of cyclohexanone oxime is one of the key processes in the production of caprolactam. In industry, cyclohexanone oxime is generally used for Beckmann rearrangement under the action of concentrated sulfuric acid or nicotinic acid. This method has disadvantages such as corrosion of equipment, high cost, and a large amount of low-value ammonium sulfate by-product. The development of a new Beckmann rearrangement process without ammonium sulfate by-product is one of the main goals of caprolactam production technology improvement. At present, the gas-phase Beckmann rearrangement of cyclohexanone oxime is more researched, which can avoid the by-product ammonium sulfate, but there are also seri...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D201/06C07D223/10
CPCY02P20/52
Inventor 罗和安尹笃林游奎一毛丽秋
Owner XIANGTAN UNIV
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