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Process for producing high purity 1,4-dioxane

A dioxane and production process technology, applied in organic chemistry and other fields, can solve problems such as high reaction temperature, many side reactions, and equipment corrosion, and achieve high yield, obvious environmental protection advantages, and low cost

Inactive Publication Date: 2004-02-11
徐汝华 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The current domestic production method of 1,4-dioxane uses diethylene glycol with sulfuric acid as a catalyst, rectification and solid alkali dehydration. The side reactions are serious, the purification of the reaction product is difficult, and the production process brings a lot of three wastes. , the product quality is poor, and it is difficult to obtain high-purity products
The continuous production method is adopted in the production of 1,4-dioxane in foreign countries. The separation of reaction products is mainly by rectification. The catalysts used are divided into three categories. The first category of catalysts is mainly mineral acid. The advantages of this type of catalyst It is a catalyst with high activity and low price, but the problems it brings are large amount of three wastes, many side reactions, serious corrosion to equipment, and difficulty in product purification. The second type of catalyst is mainly strongly acidic ion exchange resin, which is characterized by no waste The acid liquid is produced, which is not corrosive to the equipment and has relatively few side reactions. The disadvantage is that the thermal stability of the resin is poor, and it is easy to deactivate at the reaction temperature.
The third type of catalyst is a zeolite catalyst such as molecular sieves. The characteristic of this type of catalyst is that no waste acid is produced during the reaction process, and the selectivity is good, but the reaction temperature is relatively high.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Add 150kg diethylene glycol and 0.15kg catalyst phosphotungstic acid, acidic ion exchange resin in the reaction kettle equipped with stirrer, temperature controller, condenser, feeder, start the stirrer and heater, the reaction temperature is controlled at 180 ℃, continuously add diethylene glycol from the feeder into the reaction kettle, so that the liquid level is always kept at the same position, and the reaction product is collected after condensation, which is a crude product.

[0012] The reaction product is separated by rectification by adding an entrainer. Add 100kg of crude product and 10kg of entrainer to a rectification kettle equipped with a temperature controller and a reflux device, gradually raise the temperature, and gradually separate according to the temperature change at the top of the tower. Azeotropes of light components, water-entrainer.

[0013] Add 0.1 kg of impurity remover NaOH in the middle and later stages of rectification to remove impuritie...

Embodiment 2

[0015] Add 150kg of diethylene glycol and 0.75kg of catalyst phosphotungstic acid and acidic ion exchange resin into the reaction kettle equipped with agitator, temperature controller, condenser and feeder, start the agitator and heater, and control the reaction temperature at 180 ℃, continuously add diethylene glycol from the feeder into the reaction kettle, so that the liquid level is always kept at the same position, and the reaction product is collected after condensation, which is a crude product.

[0016] The reaction product is separated by adding an entrainer for rectification. Add 100kg of crude product and 30kg of entrainer to a rectification kettle equipped with a temperature controller and a reflux device, gradually raise the temperature, and gradually separate according to the temperature change at the top of the tower. Azeotrope of light component water-azeotrope.

[0017] Add 1 kg of impurity remover NaOH in the middle and late stage of rectification to remove i...

Embodiment 3

[0019] Add 150kg of diethylene glycol and 0.45kg of catalyst phosphoric acid and acidic ion exchange resin into the reaction kettle equipped with a stirrer, temperature controller, condenser, and feeder, start the agitator and heater, and control the reaction temperature at 180°C , The feeder continuously feeds diethylene glycol into the reaction kettle to keep the liquid level at the same position. The reaction product is collected after condensation and is a crude product.

[0020] The reaction product is separated by adding an entrainer for rectification. Add 100kg of crude product and 20kg of entrainer to a rectification kettle equipped with a temperature controller and a reflux device, gradually raise the temperature, and gradually separate according to the temperature change at the top of the tower. Azeotrope of light component water-azeotrope.

[0021] Add 0.5 kg of impurity remover NaOH in the middle and late stages of rectification to remove impurities, collect fracti...

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PUM

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Abstract

The present invention discloses the production process of high purity 1, 4-dioxane. Diglycol material is produced into high purity 1, 4-dioxane via dewatering and annulation at 150-200 deg.c in the presence of liquid and solid catalysts; low temperature dewatering via adding azeotrope, and eliminating impurity with added impurity eliminating agent. The present invention has less catalyst consumption, high yield, low cost, and no waste water and waste gas exhausted.

Description

Technical field [0001] The invention relates to a chemical synthesis method, in particular to a production process of high-purity 1,4-dioxane. Background technique [0002] 1,4-Dioxane is an excellent organic solvent with a wide range of uses. It is mainly used as the reaction medium in the drug synthesis process and the extraction agent in the drug purification process. It is used in the production of 1, 1, 1-trichloroethane As a stabilizer, it can replace solvents such as dimethylformamide and tetrahydrofuran in the production of polyurethane synthetic leather. The current domestic method of producing 1,4-dioxane uses diethylene glycol with sulfuric acid as a catalyst, rectification and solid alkali dehydration. The side reactions are serious, the purification of the reaction product is difficult, and the production process brings a lot of three wastes. , the product quality is poor, and it is difficult to obtain high-purity products. The continuous production method is ...

Claims

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Application Information

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IPC IPC(8): C07D319/12
Inventor 钱仰东余步谷葛扣荣
Owner 徐汝华
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