A method for co-producing methylbenzoic acid, methylbenzoic acid ester and phthalic acid diester

A technology of methyl benzoate and phthalic acid diester, applied in the field of fine chemical industry, can solve the problems of low yield of target product, large amount of solid waste, single product structure, etc., so as to improve yield and reduce solid waste. The effect of reducing the amount of production and loss

Active Publication Date: 2021-02-02
JIANGXI KEYUAN BIOPHARM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0020] The purpose of the present invention is to solve the problems in the prior art such as low yield of target product, large amount of solid waste, single product structure, etc., and provide a co-production methyl alcohol with simple process, low equipment investment, environmental protection and good comprehensive benefits. Methods for Benzoic Acids, Methylparabens and Diesters of Phthalates

Method used

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  • A method for co-producing methylbenzoic acid, methylbenzoic acid ester and phthalic acid diester
  • A method for co-producing methylbenzoic acid, methylbenzoic acid ester and phthalic acid diester
  • A method for co-producing methylbenzoic acid, methylbenzoic acid ester and phthalic acid diester

Examples

Experimental program
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Effect test

Embodiment 1

[0105] The catalyst that dissolves in the fresh p-xylene that adds in the oxidation reactor is cobalt naphthenate, metal phthalocyanine (R with general formula (IV) structure 1 =CH 3 CH 2 , R 2 =H, M=Mn), the metalloporphyrin (R 1 = R 2 = H, R 3 =CH 3 , M=Cu) mixture, the total concentration is 75ppm, the reaction temperature is 180°C, the reaction pressure is 2MPa, the oxygen-containing gas is the oxygen-enriched air of 24% oxygen concentration, the residence time of the reactants in the oxidation reactor is adjusted to make the The conversion rate of xylene was 42%, and the oxidation reaction solution was obtained. At this time, the mass percentage of each component in the reaction solution obtained by HPLC analysis is listed in Table 1. In the initial distillation tower, the boiling point in the oxidation reaction liquid is lower than all components of p-methylbenzyl alcohol for rectification and separation, and when the content of p-methylbenzyl alcohol in the bottom...

Embodiment 2

[0108] The catalyst dissolved in fresh p-xylene fed to the oxidation reactor was MnO 2 And cobalt acetylacetonate, total concentration is 350ppm, and reaction temperature is 150 ℃, and reaction pressure is 1MPa, oxygen-containing gas concentration 21%, operation process is identical with embodiment 1, and difference is that the conversion rate control of p-xylene is 50% , the mass percent content of p-methylbenzyl alcohol in the initial distillation tower still liquid is controlled to be 0.07%. The mass percent composition of each component that HPLC analysis obtains in the reaction solution is listed in Table 1, and the quality, composition and the content of methylbenzoic acid in the first distillation column tower bottom liquid that obtains are listed in the table 2.

[0109] The liquid in the first distillation tower was rectified to obtain 889.4 g of p-toluic acid product with a purity of 99.0% at the top of the tower, and 1226.0 g of a high-boiling liquid in the bottom ...

Embodiment 3

[0111] Add the catalyst dissolved in the fresh p-xylene in the oxidation reactor to be N-hydroxyphthalimide, cobalt isooctanoate, metal phthalocyanine (R with general formula (IV) structure 1 =OH,R 2 =H, M=Ru) and metalloporphyrins (R 1 = R 3 = H, R 2 =OH,M 1 = M 2 =Mn) mixture, the total concentration is 10000ppm, the reaction temperature is 116 ° C, the reaction pressure is 0.2MPa, the oxygen-containing gas is pure oxygen, the operation process is the same as in Example 1, and the difference is that the conversion rate of p-xylene is controlled as 60%, and the mass percent content of p-methylbenzyl alcohol in the bottom liquid of the primary distillation tower is controlled to be 0.10%. The mass percent composition of each component that HPLC analysis obtains in the reaction solution is listed in Table 1, and the quality, composition and the content of methylbenzoic acid in the first distillation column tower bottom liquid that obtains are listed in the table 2.

[01...

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Abstract

The invention discloses a method for co-producing methyl benzoic acid, methyl benzoate and phthalic acid diester, comprising: (1) continuously feeding xylene, a catalyst and an oxygen-containing gas into an oxidation reactor to carry out reaction, by controlling the amount of oxygen-containing gas to control the tail oxygen concentration to be no more than 5%, to obtain an oxidation reaction liquid; (2) enter the obtained oxidation reaction liquid into an initial distillation tower for rectification separation, to obtain low boiling point components and initial (3) enter the rectifying tower still liquid into the rectifying tower for rectification to obtain toluic acid product and rectifying tower still liquid; (4) mix the rectifying tower tower liquid with alcohol , carry out the esterification reaction, control the reaction end point to be that the content of toluic acid<0.5wt%, obtain the esterification reaction solution; (5) carry out rectification separation with the esterification reaction solution obtained, obtain methyl benzoic acid ester respectively and diester phthalate products. The invention has the advantages of simple process, less equipment investment, environmental protection and good comprehensive economic benefits.

Description

technical field [0001] The invention relates to the technical field of fine chemicals, in particular to a method for co-producing methyl benzoic acid, methyl benzoate and phthalic acid diester. Background technique [0002] Toluic acid esters include m-toluic acid esters, p-toluic acid esters and o-toluic acid esters, which are widely used in medicine, pesticides, photosensitive materials and dye intermediates. The production of existing methyl benzoic acid ester all takes high-purity methyl benzoic acid as raw material, after the methyl benzoic acid ester is prepared by esterification, the product is refined and purified by rectification. Due to the high boiling point of the product, more rectification residues will be produced in the rectification process, resulting in a large amount of solid waste residue in the rectification column and low product yield. Generally, the molar yield based on toluic acid is not more than 90%. [0003] Phthalate diesters include isophthala...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C63/04C07C51/265C07C51/44C07C69/78C07C69/82C07C69/80C07C67/08C07C67/54C07C63/26C07C63/24C07C63/16
CPCC07C51/265C07C51/44C07C67/08C07C67/54C07C63/04C07C69/78C07C63/26C07C69/82C07C69/80C07C63/24C07C63/16
Inventor 王勤波熊振华宗匡曹金辉曾鹏
Owner JIANGXI KEYUAN BIOPHARM
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