Method for producing terephthalic acid

A technology of terephthalic acid and its manufacturing method, which is applied to the preparation of carboxylate, chemical instruments and methods, and the preparation of organic compounds, etc., can solve the problems of reducing the amount of residues, and achieve the effects of improving production efficiency and reducing SS concentration

Inactive Publication Date: 2016-10-12
MITSUBISHI CHEM CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In the above-mentioned purification method, in order to completely dissolve the poorly water-soluble terephthalic acid, a large amount of water is required.
In addition, since it is necessary to minimize the amount of aliphatic carboxylic acids such as acetic acid used as a solvent remaining in the product, a large amount of water is also required for cleaning.

Method used

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  • Method for producing terephthalic acid
  • Method for producing terephthalic acid
  • Method for producing terephthalic acid

Examples

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Embodiment 1

[0234] In the manufacturing equipment of terephthalic acid (production speed 94 tons / hour), while continuously supplying p-xylene, acetic acid of 2.5 times the weight of p-xylene, mother liquor of 6.3 times the weight of p-xylene to the oxidation reaction device, as Cobalt acetate, manganese acetate, and hydrogen bromide as catalysts were oxidized while adjusting the temperature to 195° C., pressure to 1.5 MPa, and reaction time (average residence time) of 90 minutes. The amount of the catalyst used was 300 ppm by weight of cobalt acetate in terms of metal relative to the solvent, 300 ppm by weight of metal in terms of metal of manganese acetate relative to the solvent, and 700 ppm of hydrogen bromide relative to the solvent. Air is used as the molecular oxygen-containing gas for performing the oxidation reaction. At this time, the oxygen content of the air was 21%.

[0235] Then, under the conditions of reaction temperature 185° C., pressure 1.1 MPa, and reaction time (avera...

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Abstract

The purpose of the present invention is to provide a method for producing terephthalic acid, the method enabling discharged water which includes turbidity produced by a terephthalic acid production process to be continuously run through a membrane separation treatment with long-term stability, and treated separated water to be efficiently reutilized for such terephthalic acid production process as a highly concentrated slurry. The present invention pertains to a method for producing terephthalic acid that includes a membrane separation step, in which discharged water that has been discharged from a terephthalic acid production process comprising an oxidation reaction step where p-xylene is oxidized in the presence of a metal compound to make crude terephthalic acid is run through a membrane separation treatment in a treatment tank equipped with a separation membrane therein, and the discharged water is separated into separated water and membrane-permeating water, the method being characterized in that aeration is performed from a lower section of the separation membrane.

Description

technical field [0001] The present invention relates to a method for producing terephthalic acid. In particular, it relates to a process for the manufacture of terephthalic acid involving efficient wastewater treatment. Background technique [0002] As an industrial production method of terephthalic acid, in a solvent containing an aliphatic carboxylic acid such as acetic acid, etc., in the presence of a catalyst of a metal compound mainly composed of cobalt, manganese, etc. and / or a bromine compound, the raw material p-xylene Aromatic hydrocarbons having an alkyl group, such as aromatic hydrocarbons, are pressurized with a gas containing molecular oxygen, and an oxidation reaction occurs in a liquid phase to generate terephthalic acid, which is widely used. [0003] Due to its commercial use, terephthalic acid is often required to reduce trace impurities as much as possible and improve its purity. In order to respond to such a request, as a purification method, (A) In ord...

Claims

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Application Information

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IPC IPC(8): C07C51/42C07C63/26
CPCC07C51/47C07C51/265C07C63/26
Inventor 岩井英郎
Owner MITSUBISHI CHEM CORP
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