Process for continuous preparation of trimellitic anhydride by step catalytic oxidation process

A technology of trimellitic anhydride and catalytic oxidation, applied in the direction of organic chemistry, can solve problems such as uneven gas distribution and affecting product quality, and achieve the effects of reducing the concentration of impurities, reducing energy consumption, and improving yield

Inactive Publication Date: 2005-03-16
CHINA PETROLEUM & CHEM CORP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The gas flow rate of intermittent operation varies with time, resulting in uneven gas distribution in the oxidation reactor, which affects product quality

Method used

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  • Process for continuous preparation of trimellitic anhydride by step catalytic oxidation process

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Effect test

Embodiment 1

[0027]Embodiment 1. With 1500kg of partial trimethylbenzene, 15000kg of acetic acid, join in the batching still 1 with conveying metering pump, then add cobalt acetate 8kg, tetrabromoethane 7kg, stir, keep temperature 80 ℃ in the batching still, simultaneously, will Add 250kg of acetic acid and 1kg of manganese acetate into the batching tank 2, stir evenly, and keep the temperature in the batching tank at 80°C. Through the reaction feed pump at 3m 3 The / h flow rate feeds in the oxidation reactor 4, and after adding about 30 minutes, stop feeding, use nitrogen air seal, heat the reaction mass to the reaction temperature, then feed compressed air through the air compressor 3 to initiate the reaction, when the reaction temperature Show an upward trend, and when the tail gas content in the reactor 4 begins to rise, with 5m 3 The feed flow rate of / h continuously adds fresh materials in the reactor 4, adjusts the total amount of compressed air intake, to control the oxygen conten...

Embodiment 2

[0028] Embodiment 2. 1000Kg of mesitylene raw material, 1500Kg of acetic acid, then add 3kg of cobalt acetate, 8kg of tetrabromoethane, stir evenly, keep the temperature in the batching kettle at 80°C, meanwhile, 150kg of acetic acid and 0.8kg of manganese acetate are added to the batching tank 2, stir evenly, and keep the temperature in the batching kettle at 80°C. Through the reaction feed pump at 2m 3 The / h flow rate feeds in the oxidation reactor 4, and after adding about 15 minutes, stop feeding, use nitrogen air seal, heat reaction mass to reaction temperature, pass into compressed air by air compressor 3 then and initiate reaction, when reaction temperature It shows an upward trend, and when the tail gas content in the reactor starts to rise, it takes 3m 3 Continuously add fresh materials into the reactor at a feed flow rate of / h, adjust the total amount of compressed air intake to control the oxygen content in the reactor tail gas at about 3-5% (vol), keep the react...

Embodiment 3

[0029] Embodiment 3. 2000kg of partial trimethylbenzene, 11000kg of acetic acid are added in the batching kettle 1 with delivery metering pump, then add cobalt acetate 7kg, tetrabromoethane 8kg, stir well, keep 80 ℃ of temperature in the batching kettle, simultaneously, will Acetic acid 350kg and manganese acetate 3kg join in the batching tank 2, stir evenly, keep temperature 80 in the batching still. Through the reaction feeding pump at 6m 3 The / h flow rate feeds in the oxidation reactor 4, and after adding about 30 minutes, stop feeding, use nitrogen air seal, heat the reaction mass to the reaction temperature, then feed compressed air through the air compressor 3 to initiate the reaction, when the reaction temperature Show an upward trend, and when the tail gas content in the reactor 4 begins to rise, with 8m 3 The feed flow rate of / h continuously adds fresh materials in the reactor 4, adjusts the total amount of compressed air intake, to control the oxygen content in th...

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Abstract

The invention provides a process for continuous preparation of trimellitic anhydride by step catalytic oxidation process by using pseudocumene as raw material, fatty group carboxylic acid as dissolvent, cobalt, manganese and bromine as catalyst, the preparing process comprises the steps of, (1) stepwise continuous catalysis oxidizing process, (2) crystallization and liquid-solid separation, (3) anhydride forming procedure, (4) subtractive process, and (5) solvent reclamation.

Description

technical field [0001] The invention relates to a method for producing trimellitic anhydride by a continuous step-by-step oxidation process. The method uses trimethylbenzene as a raw material, lower aliphatic carboxylic acid (such as acetic acid) as a solvent, adopts a cobalt, manganese and bromine catalytic system, and performs liquid-phase oxidation reaction of the trimethylene with gas containing oxygen molecules. After a certain period of oxidation, trimellitic acid production is carried out by again carrying out the addition of catalyst. Compared with the original domestic batch production process, the continuous step-by-step oxidation production method makes the yield of the product reach 90 (mol)%. At the same time, the safety of the oxidation reaction system is improved, the product quality is stable, the service life of the equipment is extended, and it is easy to use in large-scale production. Large-scale industrial production. Background technique [0002] Trime...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/89
Inventor 刘建新姚小利沈建新张奇
Owner CHINA PETROLEUM & CHEM CORP
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