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Technology for producing hydroquinone by hydrolysis of p-aminophenol through continuous method

A technology of p-aminophenol and hydroquinone, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of high energy consumption, large amount of waste water, low production capacity, etc., and achieve reduction of side reactions, Effects of reduced waste water and high yield

Inactive Publication Date: 2014-06-25
中国中化股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The present invention aims at the problems of large amount of waste water, low production capacity and high energy consumption in the process of producing hydroquinone by intermittent hydrolysis of p-aminophenol, and proposes a process for producing hydroquinone by continuous hydrolysis, using p-aminophenol hydrochloric acid Saline solution is used as raw material to obtain hydroquinone by heating and hydrolyzing

Method used

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  • Technology for producing hydroquinone by hydrolysis of p-aminophenol through continuous method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Replace the air in the batching system and hydrolysis reaction device with nitrogen. Add water, 30% hydrochloric acid and p-aminophenol hydrochloride into the batching tank (2), the molar ratio of p-aminophenol hydrochloride:hydrochloric acid:water is 1:3:100. Through the metering pump (3), the hydrolyzed raw material passes through the pipeline mixer (4) at a flow rate of 13Kg / min, passes through the heat exchanger-2 (5), and then heats up to 230°C through the heat exchanger-1 (6). The material feed port at the top of the reactor (7) enters the tower reactor (7). The tower reactor (7) has a volume of 1.5m3 and a diameter-to-height ratio of 10. The reaction temperature is 230°C. At the same time, the circulation pump (8) is used to continuously extract the hydrolyzed liquid at the bottom of the tower and circulate it so that the reaction material stays in the tower for 300 minutes, and the hydrolyzed reaction liquid overflows from the upper part of the tower reactor (7)...

Embodiment 2

[0032]According to the method described in Example 1, the difference is that the controlled hydrolysis reaction time is 200 minutes. During the hydrolysis reaction, the conversion rate of p-aminophenol hydrochloride is 50%. The water phase of the extraction tower (1) is transported from the bottom of the extraction tower to the batching tank (2), and p-aminophenol hydrochloride is added continuously. The additional amount is The transformation amount of p-aminophenol hydrochloride in the reaction scheme. The organic phase of the extraction tower was desolvated and distilled to obtain hydroquinone with a purity of 99.5%, yield: 95%.

Embodiment 3

[0034] According to the method described in Example 1, the difference is that the controlled hydrolysis reaction time is 150 minutes. During the hydrolysis reaction, the conversion rate of p-aminophenol hydrochloride is 40%. The water phase of the extraction tower (1) is transported from the bottom of the extraction tower to the batching tank (2), and p-aminophenol hydrochloride is added continuously. The additional amount is The transformation amount of p-aminophenol hydrochloride in the reaction scheme. The organic phase of the extraction tower was desolvated and distilled to obtain hydroquinone with a purity of 99.5%, yield: 98%.

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Abstract

The invention relates to a technology for producing hydroquinone by hydrolysis of p-aminophenol through a continuous method, which takes para aminophenol hydrochloride as a raw material, the para aminophenol hydrochloride is mixed with hydrochloric acid, preheated to 220-240 DEG C, a hydrolysis reaction is carried out for 150-420 minutes in a tower type reactor, after the reaction is finished, a hydrolysis reaction solution overflows from a discharge hatch of the tower type reactor, the hydrolysis reaction solution is subjected to extraction, phase-splitting and desolvation to obtain the hydroquinone crude product. The technology for producing hydroquinone has the advantages of little waste water in a reaction system, continuous production, high production efficiency, high yield and simple technology control.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a process for producing hydroquinone by continuous hydrolysis of p-aminophenol. Background technique [0002] Hydroquinone is an important organic chemical raw material. It is an important raw material in the fields of rubber, medicine, dye, pesticide and food, and has a large market demand. Foreign manufacturers generally use phenol hydrogen peroxide hydroxylation and dicumyl peroxidation to produce hydroquinone. Although the domestic production capacity is relatively large, almost all of them use the aniline oxidation method that has been eliminated abroad. This method has serious equipment corrosion, and produces a large amount of manganese sulfate, ammonium sulfate waste liquid and iron sludge, which seriously pollutes the environment and is facing elimination. [0003] The method of preparing hydroquinone by direct hydrolysis of p-aminophenol has the advantages ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/08C07C37/05
CPCC07C37/05C07C39/08
Inventor 李付刚闫士杰鄢冬茂
Owner 中国中化股份有限公司