Coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester

A technology of methyl benzoate and phthalate diester, which is applied in the field of fine chemicals, can solve the problems of low yield of target products, large amount of solid waste, and single product structure, so as to increase yield and reduce solid waste The effect of reducing the amount of generation and loss

Active Publication Date: 2018-05-18
JIANGXI KEYUAN BIOPHARM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

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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  • Coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester
  • Coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester
  • Coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester

Examples

Experimental program
Comparison scheme
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.

[0...

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Abstract

The invention discloses a coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester. The method comprises the following steps: (1) continuously introducing xylene, a catalyst and oxygen-containing gas into an oxidation reactor for a reaction, and controlling oxygenic concentration in the tail gas to not exceed 5% by controlling introduction amount of the oxygen-containing gas to obtain an oxidation reaction liquid; (2) feeding the obtained oxidation reaction liquid into a predistillation tower for distillation separation to obtain a low-boiling-point component and a predistillation tower bottom liquid; (3) feeding the predistillation tower bottom liquid into a distillation tower for distillation to obtain a methylbenzoic acid product and a distillationtower bottom liquid; (4) mixing the distillation tower bottom liquid and alcohol for an esterification reaction, and controlling the reaction endpoint to be lower than 0.5wt% of the content of methylbenzoic acid to obtain an esterification reaction liquid; (5) performing distillation separation on the obtained esterification reaction liquid to obtain methyl benzoate and benzenedicarboxylic acid diester products. The method has the advantages that the process is simple, equipment investment is low, and the method is environmentally friendly and has 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 Applications(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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