Method for continuously preparing epsilon-lactone

A caprolactone, continuous technology, applied in organic chemistry and other directions, can solve the problems of reducing production efficiency, occupying time, increasing control difficulty, etc., to improve production efficiency, reduce start-up and stop time, and reduce fluctuations in process parameters.

Active Publication Date: 2014-02-12
CHINA PETROLEUM & CHEM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The addition and discharge, heating and cooling of materials in each kettle takes time, which reduces production efficiency, and p

Method used

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  • Method for continuously preparing epsilon-lactone

Examples

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Example Embodiment

[0028] The cyclohexanone used in the preparation method of the present invention is preferably a compound having a purity of 99% by weight or more.

[0029] The content of ε-caprolactone in the obtained crude ε-caprolactone solution is preferably 10-50%, the rest are carboxylic acid and organic solvent, the content of peroxycarboxylic acid is less than 3%, and the content of cyclohexanone is less than 0.7% .

[0030] The purification step of separating ε-caprolactone from the crude ε-caprolactone solution can be carried out according to a common distillation method. For example, the ε-caprolactone solution is rectified through two rectification towers, Enter tower C1, distill organic solvent and carboxylic acid from the top of the tower, and the liquid from the tower still enters tower C2, distills high-purity caprolactone from the top of the tower, and the liquid containing high-boiling impurities and boric acid is discharged from the tower still. In order to suppress the po...

Example Embodiment

[0036] Example 1

[0037] In this example, an acetic acid / ethyl acetate system is used, and two kettles are connected in series for the preparation of peroxyacetic acid and the preparation of ε-caprolactone, and the total residence time is 2h. The composition of the reaction solution was: acetic acid 20%, ethyl acetate 79.8%, and boric acid 0.2%.

[0038] Preparation of peracetic acid solution

[0039] The reaction solution was pumped into A1 from pipe 2 at a rate of 595 g / h. At the same time, the hydrogen peroxide with a content of 50% was sent to the middle of the A1 tower from the pipe 1 at a speed of 119g / h, the system pressure was adjusted to 40~50kPa, and the liquid temperature in the kettle was controlled to be 65~80℃, and the boiling in the kettle was maintained, and the gas phase was maintained. It rises to the top of the tower through the rectification column, and is layered in the water separator after condensation. The lower water phase is continuously discharged t...

Example Embodiment

[0047] Example 2

[0048] In this example, a propionic acid / ethyl acetate system is used, and three kettles are connected in series for the preparation of peroxypropionic acid and the preparation of ε-caprolactone, and the total residence time is 4.5h. The composition of the reaction solution was: propionic acid 40%, ethyl acetate 59.6%, and boric acid 0.4%.

[0049] Preparation of peroxypropionic acid solution

[0050] The reaction solution was pumped into A1 from pipe 2 at a rate of 440 g / h. At the same time, the hydrogen peroxide with a content of 50% is sent to the middle of the A1 tower from the pipe 1 at a speed of 68g / h with a pump, the system pressure is adjusted to 15~25kPa, and the liquid temperature in the kettle is controlled to be 60~70℃, and the boiling in the kettle is maintained, and the gas phase is maintained. It rises to the top of the tower through the rectification column, and is layered in the water separator after condensation. The lower water phase is...

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Abstract

The invention discloses a method for continuously preparing epsilon-lactone. The method for continuously preparing the epsilon-lactone comprises the following steps: in the presence of boric acid, continuously oxidizing a carboxylic acid solution by adopting hydrogen peroxide in multiple stirring reaction kettles provided with a rectifying tower, continuously introducing the obtained percarboxylic acid and cyclohexanone into the multiple stirring kettles which are connected in series, carrying out a reaction to obtain an epsilon-lactone solution, and carrying out continuous rectification, thus high-purity epsilon-lactone is obtained.

Description

technical field [0001] The invention relates to a method for continuously preparing ε-caprolactone by reacting a peroxycarboxylic acid solution obtained by continuously oxidizing carboxylic acid in an organic solvent with a hydrogen peroxide solution in the presence of a boric acid catalyst, and reacting with cyclohexanone. Background technique [0002] In the existing process, it is known that ε-caprolactone is prepared by reacting cyclohexanone with peroxycarboxylic acid, and the peroxycarboxylic acid used includes peroxyacetic acid and peroxypropionic acid. A method has been proposed in which a boric acid catalyst which produces only a small amount of by-products in the production of ε-caprolactone is used instead of a strongly acidic catalyst such as sulfuric acid in the production of peroxycarboxylic acid for oxidation of cyclohexanone, The peroxycarboxylic acid solution thus obtained can be used in the preparation of, for example, ε-caprolactone. In particular, in Jap...

Claims

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Application Information

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IPC IPC(8): C07D313/04
CPCC07D313/04
Inventor 周小文刘洪武黎树根汤照龙邓琼韩娟彭志斌
Owner CHINA PETROLEUM & CHEM CORP
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