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Method for producing trimellitic anhydride with pseudocumene liquid phase air segmenting hydrocarbonylation

A technology of trimellitic anhydride and trimethylene, applied in the direction of organic chemistry, etc., can solve the problems of low air utilization rate, low conversion rate of trimellitylene, air waste, etc., and achieve the effect of solving the self-inhibition effect.

Active Publication Date: 2009-04-08
安徽泰达新材料股份有限公司
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  • Abstract
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  • Claims
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AI Technical Summary

Problems solved by technology

The disadvantage is that the oxidation of trimellitic anhydride has not yet been solved in the presence of a catalyst, and self-inhibition occurs, that is, the partially oxidized product produced forms a complex with the catalyst, resulting in a passivation of the catalyst activity, thereby limiting the yield of trimellitic anhydride to 65%. In the range of ~75%, further increasing the yield of trimellitic anhydride has become the biggest obstacle
This step-by-step catalytic oxidation is carried out continuously at two reactors connected in series. In fact, the continuous process of turning one reactor into two reactors is not an ideal continuous method. rate is also affected
2. Continuous operation optimization cannot be realized
[0006] 1. The air is used to enter the reaction kettles at all levels in parallel, the air utilization rate is low, and most of the air is wasted. If the air is used to enter the reaction kettles in the next stage in series, the air will be fully utilized

Method used

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  • Method for producing trimellitic anhydride with pseudocumene liquid phase air segmenting hydrocarbonylation
  • Method for producing trimellitic anhydride with pseudocumene liquid phase air segmenting hydrocarbonylation

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Experimental program
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Effect test

Embodiment 1

[0020] The preparation of embodiment 1 partial anhydride

[0021] The main production process steps are as follows:

[0022] 1. Put 400Kg of mesitylene and 1000Kg of acetic acid into the mixing kettle, add 1.2Kg of cobalt acetate and 1.2Kg of tetrabromoethane. Control the mixing temperature to 60°C, start stirring and mixing to completely dissolve the catalyst.

[0023] 2. Put the mixture into the oxidation tower, raise the temperature to 140°C and the pressure to 1.0Mpa, introduce air to initiate a stage of oxidation reaction, control the oxidation temperature to 140-180°C, and the oxidation pressure to 0.4-1.0Mpa. After initiating for 30 minutes, put into the prepared catalyst, including 0.8Kg of cobalt acetate, 0.8Kg of tetrabromoethane, and 0.8Kg of manganese acetate. Control oxidation temperature 180-300℃, pressure 1.0-3.0Mpa, adjust air flow to 2000m 3 / h. Oxidation ends when the oxygen content of the tail gas reaches 18-20%.

[0024] 3. The oxide material is dehydr...

Embodiment 2

[0026] The preparation of embodiment 2 partial anhydrides

[0027] The main production process steps are as follows:

[0028] 1. Put 200Kg of mesitylene and 2000Kg of acetic acid into the mixing kettle from the metering tank, then add 4Kg of cobalt acetate and 4Kg of tetrabromoethane. Control the mixing temperature to 100°C, start stirring and mixing.

[0029] 2. Put the mixed material into the oxidation tower, control the oxidation temperature to 180°C, and the pressure to 0.4Mpa, introduce air to trigger a stage of oxidation reaction, control the oxidation temperature to 140-180°C, and the oxidation pressure to 0.4-1.0Mpa. After triggering for 60 minutes, drop into the prepared catalyst, including 6Kg of cobalt acetate, 6Kg of tetrabromoethane, and 10Kg of manganese acetate. Control the oxidation temperature at 180-300°C, the pressure at 1.0-3.0Mpa, and adjust the air flow to 1000m 3 / h. Oxidation ends when the oxygen content of the tail gas reaches 18-20%.

[0030] 3. ...

Embodiment 3

[0032] The preparation of embodiment 3 partial anhydrides

[0033] The main production process steps are as follows:

[0034]1. Put 400Kg of mesitylene and 2400Kg of acetic acid into the mixing tank from the metering tank, then add 2.7Kg of cobalt acetate and 2.7Kg of tetrabromoethane. The temperature of the mixing tank was controlled at 80°C, and the stirring was started.

[0035] 2. Put the mixed material into the oxidation tower, control the temperature at 150°C, the pressure at 0.8Mpa, and let in air. A period of oxidation reaction is initiated, the oxidation temperature is controlled at 140-180°C, and the oxidation pressure is 0.4-1.0Mpa. After triggering for 50 minutes, drop into the prepared catalyst, including 3.3Kg of cobalt acetate, 3.3Kg of tetrabromoethane, and 6Kg of manganese acetate. Control oxidation temperature 180-300℃, pressure 1.0-3.0Mpa, adjust air flow to 2000m 3 / h. Oxidation ends when the oxygen content of the tail gas reaches 18-20%.

[0036] 3. ...

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Abstract

The invention relates to a method for producing trimellitic anhydride by using a pseudocumene liquidoid air subsection oxidation method. Pseudocumene is used as a raw material, acetic acid is used as a solvent, and cobalt acetate, manganese acetate, and tetrabromoethane are used as catalysts; the solvent weight ratio of pseudocumene to acetic acid is between 1 to 2.5 and 1 to 10; and the weight ratio of the total catalysts to the pseudocumene is as follows: the ratio of the pseudocumene to the cobalt acetate to the manganese acetate to the tetrabromoethane is 1 to 0.005-0.05 to 0.005-0.05 to 0.005-0.05. The method comprises the following: a step of mixture, in which the pseudocumene and the acetic acid are weighed out according to the proportion, are added with the cobalt acetate and the tetrabromoethane which account for 40 to 60 percent of the total weight at a temperature between 60 and 100 DEG C; a step of subsection oxidation, in which the mixed materials enter the first reaction period which lasts for 30 to 50 minutes from the beginning of the oxidation, at a temperature between 140 and 180 DEG C and at a pressure of between 0.4 and 1.0 Mpa, then enter the second reaction period at a temperature of 180 and 300 DEG C and at a pressure of between 1.0 and 3.0 Mpa, and finally are added with the residual catalysts; a step of anhydride formation; and a step of fine purification. The method effectively solves the problem of self-inhibition in oxidation reaction.

Description

technical field [0001] The invention relates to a preparation method of trimellitic anhydride, in particular to a method for producing trimellitic anhydride by liquid-phase air staged oxidation of trimellitic anhydride. Background technique [0002] Trimellitic anhydride (TMA) is short for partial anhydride, also known as 1,2,4-benzenetricarboxylic anhydride, and its appearance is white or slightly yellow needle-like crystals. The molecular structure of trimellitic anhydride contains carboxylic acid and acid anhydride structure, which has the chemical properties of benzoic acid and phthalic anhydride. It can react with alcohol to form ester or polyester, react with alkali to form salt, and react with ammonia (amine) to form amide-imide. Condensation reactions with hydrocarbons under the action of catalysts, etc., making it suitable for the production of PVC resin plasticizers, polyimide resin paints, water-soluble alkyd resins, epoxy resin curing agents, impregnants for low-...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/89
Inventor 柯伯成柯伯留柯宝来罗建立方天舒张五星
Owner 安徽泰达新材料股份有限公司
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