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Continuous production method of trimellitic acid

A trimellitic acid and production method technology, applied in the field of trimellitic acid production, can solve the problems of many by-products, low product yield, large equipment investment, etc., and achieve high conversion rate, high product purity, and high yield Effect

Inactive Publication Date: 2016-12-07
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages of batch liquid-phase air oxidation method are long reaction time, many by-products and low product yield.
The yield of the trimellitic acid obtained by this method is not high and the purity of the trimellitic acid is not paid attention to, and the tower type oxidation reaction equipment is characterized in that the equipment investment is large, and it is easy to cause problems such as solid material clogging and blockage, and the operation is relatively complicated. Difficult to control stably
[0005] Currently available patent documents mainly focus on improving the conversion rate of trimellitic acid and the yield of trimellitic acid in the oxidation reaction, but the purification process of trimellitic acid has not yet been mentioned.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Add 4000Kg of trimethylene, 20000Kg of acetic acid, 80Kg of cobalt acetate, 80Kg of manganese acetate and 80Kg of tetrabromoethane into the pre-mixing tank per hour, mix by mechanical stirring and preheat to 110°C. The preheated reaction raw materials first enter the first stirred tank oxidation reactor, the oxidation temperature is controlled at 170°C, and the residence time is 160min; the reaction materials from the first oxidation reactor are pumped into the second oxidation reactor, Control the oxidation to 220°C, and the residence time is 120min; at the same time, the compressed air is first passed into the second oxidation reactor and then into the first oxidation reactor at a speed of 32000Kg / h, and the pressure in the second oxidation reactor is controlled to be 2.2 MPa, the pressure in the first oxidation reactor is 1.9MPa.

[0041] Put the oxidized mixture into three crude crystallizers in series to lower the temperature step by step, the temperature drop betw...

Embodiment 2

[0044] Add 4000Kg of trimethylene, 12000Kg of acetic acid, 40Kg of cobalt acetate, 40Kg of manganese acetate and 60Kg of tetrabromoethane into the pre-mixing tank per hour, mix by mechanical stirring and preheat to 100°C. The preheated reaction raw materials first enter the first stirred tank oxidation reactor, the oxidation temperature is controlled at 180°C, and the residence time is 90 minutes; the reaction materials from the first oxidation reactor are pumped into the second oxidation reactor, Control the oxidation to 200°C, and the residence time is 120min; at the same time, the compressed air is first passed into the second oxidation reactor and then into the first oxidation reactor at a speed of 36000Kg / h, and the pressure in the second oxidation reactor is controlled to be 1.8 MPa, the pressure in the first oxidation reactor is 1.6MPa.

[0045] Put the oxidized mixture into three series-connected crude crystallizers to lower the temperature step by step, the temperatur...

Embodiment 3

[0048] Add 4000Kg of trimethylene, 24000Kg of acetic acid, 120Kg of cobalt acetate, 120Kg of manganese acetate and 120Kg of tetrabromoethane into the pre-mixing tank per hour, mix by mechanical stirring and preheat to 80°C. The preheated reaction raw materials first enter the first stirred tank oxidation reactor, the oxidation temperature is controlled at 180°C, and the residence time is 80 minutes; the reaction materials from the first oxidation reactor are pumped into the second oxidation reactor, Control the oxidation to 230°C, and the residence time is 60min; at the same time, the compressed air is first passed into the second oxidation reactor and then into the first oxidation reactor at a speed of 40000Kg / h, and the pressure in the second oxidation reactor is controlled to be 2.4 MPa, the pressure in the first oxidation reactor is 1.6MPa.

[0049] Put the oxidized mixture into four crude crystallizers connected in series to lower the temperature step by step, the tempera...

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PUM

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Abstract

The invention discloses a continuous production method of trimellitic acid. The method comprises the following processes of premixing, oxidation, coarse crystallization, filtration and recrystallization, which are sequentially performed, and comprises the following specific processes of (1) performing premixing: mixing raw materials namely unsym-trimethyl benzene, a solvent namely acetic acid, main catalysts namely cobalt acetate and manganese acetate, and a cocatalyst namely tetrabromoethane, and performing preheating to 60-120 DEG C, wherein the mass ratio of the unsym-trimethyl benzene to the acetic acid is 1 to (2-10); (2) performing oxidation: performing 2-4 continuous oxidation stages which are in series connection, and enabling the reaction temperature of the later oxidation stage to be higher than that of the previous oxidation stage; (3) performing coarse crystallization: performing coarse crystallization and then performing centrifugal separation; (4) performing filtration: dissolving crude trimellitic acid in water of 80-100 DEG C, controlling the percentage by mass of the trimellitic acid to be 15-35%, and filtering a hot solution when the solution is still hot; and (5) performing recrystallization: performing recrystallization and then performing centrifugal separation. According to the method disclosed by the invention, the trimellitic acid products with high conversion rate, high yield and high purity can be obtained.

Description

technical field [0001] The invention relates to a continuous production method for producing trimellitic acid through a liquid-phase air oxidation method of trimellitic acid. Background technique [0002] Trimellitic acid, also known as 1,2,4-benzenetricarboxylic acid, is an important chemical intermediate with high reactivity. Trimellitic acid can react with alcohol to generate ester or polyester, react with ammonia to generate amide or imide, and undergo condensation reaction with hydrocarbon under the action of catalyst, etc. Therefore, trimellitic acid is an essential raw material for the production of plasticizers with high temperature resistance, and is also an important raw material for the production of epoxy polyester powder coatings. It is widely used in water treatment agents, film films, and low-voltage pulse power containers. . [0003] In industry, trimellitic acid is mainly prepared by the liquid-phase air oxidation method of methylene trimethylbenzene, whic...

Claims

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Application Information

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IPC IPC(8): C07C51/265C07C51/43C07C63/307
Inventor 王晨静张国娟李传清
Owner CHINA PETROLEUM & CHEM CORP
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