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Method for producing Epsilon-hexanolactam with cyclohexanone oxime gas-phase beckmann rearrangement

A Beckmann rearrangement, cyclohexanone oxime technology, applied in the preparation of lactams, chemical instruments and methods, chemical recovery and other directions, can solve the problems of catalyst deactivation, short catalyst life, unable to meet the requirements of industrialization, etc.

Active Publication Date: 2009-05-13
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The research results show that most catalysts have a certain activity, but the common disadvantage is that the catalyst is easy to deactivate, and the catalyst life is short and cannot meet the requirements of industrialization.
Therefore, the problem of catalyst deactivation is a ubiquitous problem in gas-phase Beckmann rearrangement reactions

Method used

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  • Method for producing Epsilon-hexanolactam with cyclohexanone oxime gas-phase beckmann rearrangement
  • Method for producing Epsilon-hexanolactam with cyclohexanone oxime gas-phase beckmann rearrangement
  • Method for producing Epsilon-hexanolactam with cyclohexanone oxime gas-phase beckmann rearrangement

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The gas-phase Beckmann rearrangement reaction of cyclohexanone oxime is carried out in an 80ml fixed-bed reactor, the inner diameter of the reactor is 28mm, and the catalyst loading capacity of the MFI structure is 20.0g catalyst (produced by Hunan Jianchang Petrochemical Co., Ltd., batch number RBS-1 , is Φ1.8mm strip shape, the bed height is 19cm, and the specific surface area is 319m 2 g -1 , the micropore specific surface area is 273m 2 g -1 , the non-microporous specific surface area is 46m 2 g -1 ; Pore volume 0.414ml / g, micropore volume 0.133ml / g).

[0025] Reaction pressure 0.1MPa, catalyst bed reaction temperature 365°C-385°C, carrier gas flow rate 4-8L / gcat / hr, vaporizer temperature control 185°C, vaporizer core 190°C, pipeline insulation 185°C, cyclohexanone oxime WHSV for 1h -1 , in the cyclohexanone oxime-methanol mixture, the concentration of cyclohexanone oxime is 35% (weight), and the water content of the reaction raw material is: 1.6% (m).

[002...

Embodiment 2

[0037] After about 802 hours of reaction through the regenerated catalyst of embodiment 1, the conversion rate of cyclohexanone oxime dropped to 99.50%. At this moment, the catalyst specific surface area was recorded as 215m 2 g -1 , at which point the weight of the catalyst increased by 11.5%. The addition of the cyclohexanone oxime-methanol mixture was stopped, purging was carried out under the condition of a nitrogen flow rate of 6L / gcat / hr, and methanol (3g / gcat / hr) was introduced at the same time, and the temperature of the reactor was lowered to 340°C. Then, the feed gas is converted from nitrogen to air (air flow rate is 8L / gcat / hr), the catalyst is heat-treated for 5 hours, and the deactivated catalyst is regenerated at a temperature of 500°C for 36 hours, and the specific surface area of ​​the catalyst is restored to 325m 2 g -1 .

[0038] After regeneration of the deactivator, the BET specific surface area was restored. The catalyst is unloaded, and the buffer so...

Embodiment 3

[0044] With the reaction conditions of Example 1, when the cyclohexanone oxime conversion rate dropped to 99.5%, stop adding the cyclohexanone oxime-methanol mixture, purging under the condition that the nitrogen flow rate was 6L / gcat / hr, and feed methanol simultaneously (3 g / gcat / hr), the reactor temperature was lowered to 340°C. The feed gas is then switched from nitrogen to air. The air flow rate was 8L / gcat / hr, the catalyst was heat-treated for 5 hours, and the deactivated catalyst was regenerated at a temperature of 500°C for 36 hours. The ammonia water-ammonium nitrate buffer solution with a pH value of 11.3 was circulated and injected into the catalyst bed through a pump, and treated at a reaction temperature of 80° C. for 1 hour. Stop feeding the buffer solution, wash with water for 2 hours, and dry at 120°C to obtain a regenerated rearrangement catalyst.

[0045] The air was changed to nitrogen at a flow rate of 6 L / gcat / hr until the temperature was lowered to 380° ...

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Abstract

The invention discloses a method for preparing epsilon-caprolactam through cyclohexanone-oxime gas-phase Beckmann rearrangement. In nitrogen atmosphere, a low-carbon alcoholic solution of cyclohexanone-oxime is in contact with a catalyst bed for rearrangement reaction, and a product is recovered. The method is characterized in that the method is carried out in a fixed-bed reactor; when the conversion rate of the cyclohexanone-oxime is lower than 99.0 percent and / or when the BET specific surface area of a catalyst decreases to be or lower than 70 percent of that of a fresh catalyst, the low-carbon alcoholic solution of the cyclohexanone-oxime is changed into a low-carbon alcohol treatment catalyst bed; the low-carbon alcohol treatment catalyst bed is swept at a temperature between 350 and 550 DEG C by use of oxygen-containing atmosphere; and after surface coking matter of catalysts is burnt out and the BET specific surface area of the catalysts is basically recovered, the low-carbon alcohol treatment catalyst bed is in contact with a buffer solution of nitrogen-containing compound at a temperature between 50 and 120 DEG C, and is washed and dried, and then reaction continues to be performed.

Description

technical field [0001] The invention relates to a method for preparing synthetic fiber and synthetic resin raw materials, more specifically to a method for preparing ε-caprolactam by gas-phase Beckmann rearrangement of cyclohexanone oxime. 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 to obtain it. This method has the disadvantages of corroding equipment, polluting the environment, and unsatisfactory economic benefits, and a relatively large amount of ammonium sulfate is produced as a by-product. [0003] The gas-phase Beckmann rearrangement of cyclohexanone oxime on solid acid catalyst is a new method to realize the sulfur-free ammonifi...

Claims

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Application Information

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IPC IPC(8): C07D201/04C07D223/10
CPCY02P20/584
Inventor 程时标张树忠赵燕慕旭宏闵恩泽
Owner CHINA PETROLEUM & CHEM CORP
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