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Method for preparing hydroquinone

A technology for hydroquinone and p-benzoquinone is applied in the electrochemical field of efficient preparation of hydroquinone, which can solve the problems of low concentration and high energy consumption, and achieve the effects of simple operation and easy separation

Active Publication Date: 2020-05-12
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In order to solve the problems in the prior art, the present invention provides a method for preparing hydroquinone, which can obtain p-benzoquinone reaction solution with increased concentration, and then enter the cathode chamber for reduction to obtain hydroquinone, which solves the problem of During the anodic oxidation of benzene or phenol into p-benzoquinone, since the concentration of the p-benzoquinone reaction solution is not high (less than 3%), a large amount of raw material benzene needs to be separated, distilled and recycled, which causes the problem of high energy consumption

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  • Method for preparing hydroquinone
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  • Method for preparing hydroquinone

Examples

Experimental program
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Effect test

Embodiment 1-1

[0051] Take 5g of p-benzoquinone benzene solution with a p-benzoquinone concentration of 2% and 1% hydroquinone aqueous solution, wherein the mass ratio of p-benzoquinone to hydroquinone is 2:1, and both are added to a 20mL glass In the sample bottle, stir at 10°C for 15 minutes and stand still for 1 minute to obtain the reaction liquid, which includes the upper oil phase layer, the lower water phase layer and the middle layer of quinhydrone suspension, and filter the above reaction liquid to obtain the filtrate and filter cake , there are oil phase and water phase of benzene in the filtrate, use HPLC to measure the concentration of p-benzoquinone and hydroquinone in oil phase and water phase respectively, wherein the concentration of p-benzoquinone is the summation of oil phase and water phase concentration, to Hydroquinone is mainly distributed in the aqueous phase. After determination, the concentration of p-benzoquinone in the filtered filtrate was 0.6%, with a residual ra...

Embodiment 1-2

[0056] Except that the hydroquinone concentration was adjusted to 2%, wherein the mass of p-benzoquinone and hydroquinone were 1:1, other parameters were the same as those in Example 1-1.

[0057] According to the above indicators, the concentration of p-benzoquinone in the filtered solution is 0.29%, the residual rate is 14.5%, the concentration of hydroquinone is 0.31%, and the residual rate is 15.5%. The filter cake and filtrate were combined and reheated to 55° C., the concentration of p-benzoquinone was determined to be 1.94%, and the recovery rate was 97%; the concentration of hydroquinone was 1.98%, and the recovery rate was 99%.

Embodiment 1-3

[0059] Except that the hydroquinone concentration was adjusted to 3%, and the mass ratio of p-benzoquinone and hydroquinone was 1:1.5, other parameters were the same as those in Example 1-1.

[0060] The concentration of p-benzoquinone in the filtered solution was determined to be 0.18% according to the above indicators, and the residual rate was 9%. The concentration of hydroquinone is 1.2%, and the residual rate is 40%. After the filter cake and the filtrate are combined, they are reheated to 55° C., and the concentration of p-benzoquinone is 1.95%, and the recovery rate is 97.5%; the concentration of hydroquinone is 2.97%, and the recovery rate is 99%.

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Abstract

The invention provides a method for preparing hydroquinone. The method comprises the following steps: carrying out anodic oxidation on benzene by adopting an electrochemical method to generate a p-benzoquinone benzene solution; reacting the p-benzoquinone benzene solution with an aqueous hydroquinone solution to obtain an oil phase layer, a water phase layer and a middle layer, wherein the middlelayer is a quinone-hydroquinone suspension formed by generated quinone-hydroquinone crystals; heating the quinone-hydroquinone suspension for dissociation again to obtain a p-benzoquinone-benzene solution; and reducing the p-benzoquinone-benzene solution obtained by dissociation at a cathode to obtain a hydroquinone product. According to the method, p-benzoquinone reaction liquid with an increasedconcentration can be obtained and then enters a cathode chamber for reduction to obtain hydroquinone, thereby overcoming the problem of high energy consumption due to the fact that the concentrationof the p-benzoquinone reaction liquid is not high and a large amount of raw benzene needs to be separated, distilled and cyclically recycled in the process of anodization of benzene or phenol into p-benzoquinone.

Description

technical field [0001] The invention relates to the technical field of hydroquinone preparation, in particular to an electrochemical method capable of efficiently preparing hydroquinone. Background technique [0002] Hydroquinone is an important fine chemical raw material and intermediate, which is widely used in the fields of medicine, pesticides, dyes, rubber, fertilizers, water treatment and liquid crystal polymers. Its uses mainly include the following aspects: (1) as a polymerization inhibitor for polymer monomers, such as styrene, butadiene, isoprene, ethyl acetate, acrylonitrile, etc.; (2) for the manufacture of photographic film (3) Used as petroleum anticoagulant, synthetic ammonia catalyst, etc.; (4) Used as an intermediate for the synthesis of carbofuran, propoxur, berberine and adrenal (5) Used in the manufacture of urease inhibitors, added before ordinary urea granulation, can produce new urea varieties with high utilization rate and long fertilizer effect peri...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25B3/04C25B9/08C25B11/04C25B15/00C25B3/25C25B9/19
CPCC25B11/04C25B15/00C25B3/25C25B9/19
Inventor 钱向阳杜旺明李俊平陈长生刘释水孔令晓黎源
Owner WANHUA CHEM GRP CO LTD
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