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A kind of method of processing o-xylene liquid phase oxidation residue

A technology of xylene liquid and phthalate ester is applied in the field of ortho-xylene liquid-phase oxidation residues, which can solve the problems of low utilization rate of residues, and achieve the effects of realizing resource utilization, avoiding coking and high efficiency.

Active Publication Date: 2019-04-23
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Aiming at the deficiencies of the traditional treatment method for the oxidation residue produced by the liquid-phase oxidation of ortho-xylene to prepare phthalic acid, the present invention provides a method for processing the residue of the liquid-phase oxidation of ortho-xylene. The method first uses catalytic esterification to dissolve The method is to liquefy the solid oxidation residue, and then use molecular distillation technology to treat the liquefied oxidation residue, to separate the aromatic acid components in the oxidation residue through esterification, and to recycle the aromatic acid ester at the same time. Environmental pollution, low utilization rate of residues, etc. At the same time, the useful components in the solid waste in the liquid phase oxidation process of o-xylene are recovered, the reaction conditions are improved, the comprehensive utilization rate of resources is improved, and the discharge of solid waste is reduced.

Method used

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  • A kind of method of processing o-xylene liquid phase oxidation residue
  • A kind of method of processing o-xylene liquid phase oxidation residue
  • A kind of method of processing o-xylene liquid phase oxidation residue

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Weigh 100g o-xylene oxidation solid residue, add 200g dimethyl phthalate, 100g methanol, 5g 98% concentrated sulfuric acid, react in an autoclave at 150°C for esterification and dissolution process, the pressure is 1.5Mpa, the reaction time 5h, flash evaporated to remove unreacted methanol, and finally formed a high-viscosity mixed liquid. The liquid obtained after esterification and dissolution is added to the feeder of the molecular distillation device. The feeder is a wiped film molecular distillation device. Turn on the vacuum pump, the pressure reaches 30Pa, the liquid is preheated to 40°C, start the wiper, and open the feeder. Sample valve, feed rate 1g / min, carry out molecular distillation at 80°C, the collected light components are aromatic acid esters, and the heavy components are high boiling oils, and the total amount of mixed aromatic acid esters obtained is 271g. Dimethyl diformate and the aromatic acid ester recovered from the residue were 71 g.

Embodiment 2-7

[0024] The reaction process of Example 1 was repeated, except that different solvent catalysts and reaction conditions were used. The specific raw material reaction conditions and results of each embodiment are listed in Table 1.

[0025] Table 1, Embodiment 2-7

[0026]

[0027]

Embodiment 8

[0029] Weigh 50g o-xylene oxidation solid residue, add 200g methyl o-toluate, 80g methanol, 3g 98% concentrated sulfuric acid, react in an autoclave at 120°C to carry out the process of esterification and dissolution, the pressure is 1.0Mpa, the reaction After 5 hours, unreacted methanol was removed by flash evaporation, and a high-viscosity mixed liquid was finally formed. The liquid obtained after esterification and dissolution is added to the feeder of the molecular distillation device. The feeder is a falling film molecular distillation device. Turn on the vacuum pump, the pressure reaches 20Pa, the liquid is preheated to 30°C, open the injection valve, and feed Speed ​​2g / min, carry out molecular distillation at 60 ℃, the light component that collects is aromatic acid ester, heavy is divided into high boiling oil, obtains mixed aromatic acid ester to be 261g, removes the 200g methyl o-toluate that adds, The aromatic acid ester recovered from the residue was 61 g.

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Abstract

The invention discloses a method for treating o-xylene liquid-phase oxidation residues. In the method, the oxidized solid residues are firstly liquefied by catalytic esterification, and the liquefied oxidation residues are processed by molecular distillation technology, and recovered from the solid residues. Aromatic acid esters. After refining, the recovered aromatic esters can be used as solvents, plasticizers, etc., and the remaining high-boiling components can be transported to the boiler room through pipelines for combustion as fuel. The method enables the comprehensive utilization of the o-xylene liquid phase oxidation residue, greatly reduces the discharge of solid waste, and realizes the resource utilization of industrial waste residue.

Description

technical field [0001] The invention relates to the field of chemistry and chemical engineering, in particular to a method for comprehensively utilizing o-xylene liquid-phase oxidation residues by using molecular distillation technology. Background technique [0002] Phthalate esters are important plasticizers, currently mainly obtained by esterification of o-xylene oxidation products (phthalic acid, phthalic anhydride). The high reaction temperature during the liquid-phase oxidation of o-xylene to prepare phthalic acid will produce a large amount of aromatic acid residues, the main components of which include phthalic acid, terephthalic acid, phthalic acid, benzoic acid, Toluic acid, o-carboxybenzaldehyde, etc. And these solid residues are highly acidic, and direct disposal methods such as landfills will cause serious environmental pollution. In the industry, the incineration method is usually used for disposal. Although this method solves environmental problems, it also w...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/80C07C69/78C07C67/54
Inventor 徐杰孙颖石松陈晨高进马红
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI