Method for preparing hydroquinone by oxidizing phenol

A technology for hydroquinone and phenol, applied in the field of phenol oxidation to prepare hydroquinone, can solve the problems of complicated separation and low operability, and achieve the effects of reducing separation difficulty and separation loss

Active Publication Date: 2016-11-23
JIANGSU YANGNONG CHEM GROUP +2
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  • Abstract
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AI Technical Summary

Problems solved by technology

The method phenol conversion rate is close to 90%, but the low selectivity produces o-benzoquinone (to / o=75 / 18), which causes subsequent separation to be more complicated. In actual operation, it is found that the phenol conversion rate is too high to produce a large amount of black tar, so Little practicality

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  • Method for preparing hydroquinone by oxidizing phenol
  • Method for preparing hydroquinone by oxidizing phenol
  • Method for preparing hydroquinone by oxidizing phenol

Examples

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Effect test

Embodiment 1

[0021] In order to better illustrate the preparation process of the supported catalyst, take the copper-cobalt catalyst supported by carbon nanotubes used in Example 1 as an example (for other catalyst preparation processes, refer to the aforementioned related patents), introduce its preparation process: 4mmol six Cobalt nitrate hydrate and 8 mmol copper nitrate trihydrate were dissolved in 60 ml DMF, and then 4 mmol trimesic acid and 2 mmol 4,4-bipyridine were added to obtain a mixed solution. The above mixed solution was transferred to an autoclave, the reaction temperature was 80°C, and the temperature was kept for 72 hours. After the heat preservation, it was naturally cooled to room temperature, and the generated crystals were washed with 30ml of DMF three times, and dried for 12 hours under a vacuum degree of -0.1MPa to obtain cobalt-copper Metal organic framework product CuCo-MOF. The obtained CuCo-MOF was calcined in a tube furnace at 600° C. for 3 hours under an argon...

Embodiment 2

[0024] Add 80g of phenol, 300g of dichloroethane, and 6g of activated carbon-supported cobalt catalyst into a 1L oxidation kettle. After sealing the kettle, 2.5MPa oxygen is introduced, and the temperature is raised to 65°C for 1.5 hours of heat preservation. Cool down and dismantle the kettle, filter out the catalyst, and obtain 378g of oxidizing solution. Analytical results: the conversion rate of phenol is 22%, and the selectivity to p-benzoquinone is 82.7%. Put 378g of oxidizing solution and 2g of 3% Pd / C catalyst into a 1L hydrogenation kettle, seal the kettle and feed 1.0MPa hydrogen gas, raise the temperature to 70°C and keep it warm for 3 hours, cool down and dismantle the kettle, filter out the hydrogenation catalyst, and obtain hydrogenation liquid. Analysis results: the conversion rate of p-benzoquinone is 99.5%, and the selectivity of hydroquinone is 95.4%. The hydrogenation solution first removes dichloroethane under normal pressure, and then carries out negativ...

Embodiment 3

[0026] Add 80g of phenol, 340g of acetic acid, and 6g of polystyrene-supported vanadium-cobalt catalyst into a 1L oxidation kettle. After sealing the kettle, 2.5MPa oxygen is introduced, and the temperature is raised to 80°C for 2 hours. Cool down and disassemble the kettle, filter out the catalyst, and obtain 415g of oxidizing solution. Analytical results: the conversion rate of phenol is 15.8%, and the selectivity to p-benzoquinone is 91.2%. Put 415g of oxidizing solution and 2g of 2% Pt / C catalyst into a 1L hydrogenation kettle, seal the kettle and feed 1.5MPa hydrogen, raise the temperature to 75°C and keep it warm for 2.5 hours, lower the temperature and dismantle the kettle, filter out the hydrogenation catalyst, and obtain hydrogenation liquid. Analysis results: the conversion rate of p-benzoquinone is 100%, and the selectivity of hydroquinone is 94.6%. The hydrogenation liquid first desorbs acetic acid under normal pressure, and then carries out negative pressure rec...

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Abstract

The invention relates to a method for preparing hydroquinone by oxidizing phenol. The method comprises the following steps: adding the phenol, a solvent and a supported catalyst into an oxidization high-pressure kettle; introducing oxygen with certain pressure and reacting at a specific temperature for certain time; after the materials are cooled, filtering out an oxidization catalyst to obtain an oxidized solution; adding the oxidized solution and a hydrogenation catalyst into a hydrogenation high-pressure kettle; introducing hydrogen and carrying out a catalytic hydrogenation reaction at a certain temperature; after the materials are cooled, filtering out the hydrogenation catalyst to obtain a hydrogenated solution; desolventizing the hydrogenated solution to obtain a mixture of the phenol and the hydroquinone; rectifying the mixture by negative pressure and separating the phenol and the hydroquinone; returning the phenol back to an oxidization procedure to be used as the raw material. The method is simple to operate and the phenol and benzoquinone do not need to be separated, so that the industrial implementation is easy to realize.

Description

technical field [0001] The invention relates to a method for preparing hydroquinone by oxidizing phenol. Background technique [0002] Hydroquinone (C 6 h 6 o 2 ), also known as hydroquinone, is an important fine chemical raw material and intermediate, widely used in the fields of medicine, pesticides, dyes, rubber, fertilizers, water treatment and liquid crystal polymers, such as polymerization inhibitors, pigments, dyes , food additives, etc. At present, the domestic market demand for hydroquinone is 30,000 to 40,000 t / a, and it will grow at a certain rate every year. Hydroquinone has a good market prospect. [0003] There are two main production processes of hydroquinone in China: aniline oxidation and phenol hydroxylation. Among them, the aniline oxidation method will be gradually eliminated due to the three wastes problem; the phenol hydroxylation method has low hydroquinone selectivity (about 45%) and the problem of by-product catechol, which restricts the output ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/58C07C37/68C07C37/74C07C39/08
CPCC07C37/58C07C37/68C07C37/74C07C39/08
Inventor 孙诚徐林丁克鸿李明马庆炎邹爱宗王敏娟
Owner JIANGSU YANGNONG CHEM GROUP
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