Preparation method and device of 2,4-dichlorphenoxyacetic acid

A dichlorophenoxyacetic acid and preparation device technology, which is applied in the direction of carboxylate preparation, organic compound preparation, feeding device, etc., can solve the problems of high cost, low content, serious pollution, etc., and achieve the reduction of waste water and easy treatment Effect

Active Publication Date: 2013-12-25
威海韩孚生化药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The present invention aims at the technical problems of serious pollution, low yield, low content and high cost in the existing synthesis method of 2,4-dichlorophenoxyacetic acid, and provides a kind of compound with good environmental protection, high yield, high content and high cost. Preparation method and device of low-cost 2,4-dichlorophenoxyacetic acid

Method used

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  • Preparation method and device of 2,4-dichlorphenoxyacetic acid
  • Preparation method and device of 2,4-dichlorphenoxyacetic acid
  • Preparation method and device of 2,4-dichlorphenoxyacetic acid

Examples

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Effect test

Embodiment 1

[0026] (1) First, put 475L of water into the dissolution tank and start stirring, then put in 475kg of chloroacetic acid weighed in 3 times, control the temperature at 10°C, stir for 30 minutes, then transfer to the high level tank of chloroacetic acid to obtain the quality The percentage concentration is 50% aqueous solution of chloroacetic acid;

[0027] (2) Put 400kg of phenol and 550kg of liquid caustic soda into the condensation kettle, and react at a temperature of 70°C for 30 minutes to obtain a phenol sodium salt solution, and then dropwise add 720kg of liquid caustic soda with a mass percentage concentration of 25% to it at the same time With 900kg of chloroacetic acid aqueous solution obtained in step (1), react while adding dropwise, the reaction temperature is 88°C, the pH value is controlled at 9, the dropping time is 1.5 hours, and the holding time is 1 hour;

[0028] (3) First transfer the above-mentioned reacted solution to an acidification kettle, adjust the p...

Embodiment 2

[0031] (1) First, put 241L of water into the dissolution tank and start stirring, then add 723kg of chloroacetic acid weighed in 6 times, control the temperature at 20 degrees, stir for 40 minutes, then transfer to the high level tank of chloroacetic acid to obtain the quality The percentage concentration is 75% aqueous solution of chloroacetic acid;

[0032] (2) Put 600kg of phenol and 797kg of liquid caustic soda into the condensation kettle, and react for 40 minutes at a temperature of 75°C to obtain a phenol sodium salt solution, and then dropwise add 956kg of liquid caustic soda with a mass percentage concentration of 27.5% to it at the same time With 1423kg of the aqueous solution of chloroacetic acid obtained in step (1), react while adding dropwise, the reaction temperature is 95°C, the pH value is controlled at 10, the dropping time is 3 hours, and the holding time is 3 hours;

[0033] (3) First transfer the above-mentioned reacted solution to the acidification kettle...

Embodiment 3

[0036] (1) First, put 237.5L of water into the dissolution tank and start stirring, then add 950kg of chloroacetic acid weighed in 8 times, control the temperature at 30°C, stir for 45 minutes, then transfer to the high level tank of chloroacetic acid to obtain Mass percent concentration is 80% chloroacetic acid aqueous solution;

[0037] (2) Put 800kg of phenol and 1,063kg of liquid caustic soda into the condensation kettle, and react for 45 minutes at a temperature of 80°C to obtain a phenol sodium salt solution, and then add 1,257kg of liquid caustic soda with a mass percentage concentration of 30% to it at the same time With 1900kg of aqueous solution of chloroacetic acid obtained in step (1), react while adding dropwise, the reaction temperature is 102°C, the pH value is controlled at 11, the time for dropping is 5 hours, and the temperature is kept for 5 hours;

[0038] (3) First transfer the above-mentioned reacted solution to the acidification kettle, adjust the pH val...

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Abstract

The invention provides a preparation method and device of 2,4-dichlorphenoxyacetic acid. The preparation method provided by the invention is used for solving the technical problems of heavy pollution, low yield, low content and high cost of the existing synthetic method of 2,4-dichlorphenoxyacetic acid; in the process of synthesizing the 2,4-dichlorphenoxyacetic acid, a special dropwise adding reactor is employed to dropwise add chloroacetic acid and caustic soda liquid simultaneously so that sodium chloroacetate generated through a reaction reacts with sodium phenate before hydrolysis; as lots of heat is released by the reaction between the chloroacetic acid and the caustic soda liquid, the reaction heat needed by condensing the sodium chloroacetate and the sodium phenate is just guaranteed; and independent preparation of brine ice which needs to be consumed to keep the sodium chloroacetate at a low temperature and heating required by a condensation reaction are also avoided. According to the invention, non-reacting phenol is recovered and wastewater is recovered to reduce the amount of the wastewater; and the wastewater contains no phenol and thus is easier to treat; and the preparation method provided by the invention can be applied to synthesis of 2,4-dichlorphenoxyacetic acid and analogues.

Description

technical field [0001] The invention relates to a preparation method and device, in particular to a preparation method and device for 2,4-dichlorophenoxyacetic acid. Background technique [0002] 2,4-dichlorophenoxyacetic acid (2,4-D for short) is an ideal plant growth regulator and herbicide, which can prevent crops from falling flowers and fruits, induce the formation of seedless fruits, promote cell division and weed control It is widely used in economic crops such as grain, vegetables, and fruits, and can increase crop production and income at an appropriate concentration. At present, there are two most common synthesis methods of 2,4-dichlorophenoxyacetic acid, one is the pre-chlorination method, and the other is the post-chlorination method. [0003] When the pre-chlorination method is used to synthesize 2,4-dichlorophenoxyacetic acid, the amount of waste water is large, which produces unpleasant odors and highly toxic dioxins, which cause serious pollution to the sur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C59/70C07C51/363C07C51/367B01J19/24B01J4/00
Inventor 王玉亭董继波宋协阳张金田刘文波
Owner 威海韩孚生化药业有限公司
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