Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for producing pyromellitic dianhydride by continuous oxidation of durene at low temperature in liquid phase

A technology of pyromellitic dianhydride and pyromellitic acid, which is applied in the field of low-temperature liquid-phase continuous oxidation production technology, to achieve the effects of easy implementation, reduced corrosion, and reduced usage

Active Publication Date: 2022-04-29
曹正国
View PDF14 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, although the process is simple for the durene gas phase method, how to improve the selectivity of the product homoanhydride, and then improve the yield and the purity of the product homoanhydride, there is no public report yet

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] A method for producing pyromellitic dianhydride by low-temperature liquid-phase continuous oxidation of durene, comprising the steps of:

[0034] (1) The mixed solution of durene, acetic acid and cobalt-manganese-bromine-zirconium-guanidine catalyst is continuously poured into the oxidation reaction tower, and the cobalt-manganese-bromine-zirconium-guanidine catalyst includes cobalt acetate, manganese acetate, Tetrabromoethane, zirconium acetate and guanidine acetate, in the mixed liquor, acetic acid is as solvent, and mesylene is 223.35 kg, and acetic acid is 1272 kg, and catalyzer uses cobalt acetate 1.35 kg, manganese acetate 1.5kg, tetrabromoethane 0.825 kg, 0.48 kg of zirconium acetate and 0.495 kg of guanidine acetate, the corresponding weight contents of each substance are: 14.89% of durene, 84.8% of acetic acid, 0.09% of cobalt acetate, 0.1% of manganese acetate, and 0.055% of tetrabromoethane, Zirconium acetate is 0.032%, guanidine acetate is 0.033%; when the l...

Embodiment 2

[0040] A method for producing pyromellitic dianhydride by low-temperature liquid-phase continuous oxidation of durene, comprising the steps of:

[0041] (1) The mixed solution of durene, acetic acid and cobalt-manganese-bromine-zirconium-guanidine catalyst is continuously poured into the oxidation reaction tower, and the cobalt-manganese-bromine-zirconium-guanidine catalyst includes cobalt acetate, manganese acetate, Tetrabromoethane, zirconium acetate and guanidine acetate, in the mixed liquor, acetic acid is as solvent, and mesylene is 291 kg, and acetic acid is 1206 kg, and catalyst uses cobalt acetate 0.525 kg, manganese acetate 1.5kg, tetrabromoethane 0.375 kg, 0.105 kg of zirconium acetate and 0.495 kg of guanidine acetate, the corresponding weight contents of each substance are: 19.4% of durene, 80.4% of acetic acid, 0.035% of cobalt acetate, 0.1% of manganese acetate, and 0.025% of tetrabromoethane, Zirconium acetate is 0.007%, guanidine acetate is 0.033%; when the liq...

Embodiment 3

[0047] A method for producing pyromellitic dianhydride by low-temperature liquid-phase continuous oxidation of durene, comprising the steps of:

[0048] (1) The mixed solution of durene, acetic acid and cobalt-manganese-bromine-zirconium-guanidine catalyst is continuously poured into the oxidation reaction tower, and the cobalt-manganese-bromine-zirconium-guanidine catalyst includes cobalt acetate, manganese acetate, Tetrabromoethane, zirconium acetate and guanidine acetate, in the mixed liquor, acetic acid is used as solvent, and mesylene is 236.25 kg, and acetic acid is 1260.75 kg, and catalyst uses cobalt acetate 1.05 kg, manganese acetate 1.005 kg, tetrabromoethane 0.285 kg, 0.45 kg of zirconium acetate and 0.21 kg of guanidine acetate, the corresponding weight contents of each substance are: 15.75% of durene, 84.05% of acetic acid, 0.07% of cobalt acetate, 0.067% of manganese acetate, and 0.019% of tetrabromoethane, Zirconium acetate is 0.03%, guanidine acetate is 0.014%;...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
melting pointaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for producing pyromellitic dianhydride by continuous low-temperature liquid-phase oxidation of mesitylene in the technical field of chemical production. The liquid is continuously pumped into the oxidation reaction tower, and oxygen-enriched gas is continuously fed into the tower while the liquid is fed, keeping the temperature in the oxidation reaction tower at 200-300°C, and the pressure in the tower at 0.5-3MPa. The generated pyromellitic acid has a low density and floats on the upper layer of the liquid surface; the liquid surface with a high content of pyromellitic acid is extracted for flash evaporation to evaporate the light components, and the bottom of the tank can obtain pyromellitic acid Crude product; the crude product of pyromellitic acid is recrystallized and centrifuged to obtain crystals of pyromellitic acid, and then dehydrated to obtain pyromellitic dianhydride. The amount of bromine in the catalyst is small, which reduces the corrosion of equipment; the process is simple, easy to realize, and is beneficial to the industrial production of pyromellitic dianhydride.

Description

technical field [0001] The invention relates to a low-temperature liquid-phase continuous oxidation production process. Specifically, the low-temperature liquid-phase continuous oxidation of durene is used to produce pyromellitic acid, and then the pyromellitic acid is dehydrated to produce pyromellitic dianhydride. It belongs to the field of chemical technology. Background technique [0002] Durene, whose chemical name is 1,2,4,5-tetramethylbenzene, is a granule / leafy crystalline substance with a camphor smell, with a melting point of 80°C, soluble in organic solvents such as ethanol, ether, acetone, and benzene , sublimation. Durene is a very important organic chemical raw material, mainly used in the production of pyromellitic acid and pyromellitic anhydride. Pyromellitic acid is obtained after oxidation of durene, and then further dehydration is obtained to obtain pyromellitic dianhydride. [0003] The 1,2,4,5-tetrasubstituted structure of durene makes it have symmetr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07D493/04B01J31/12
CPCC07D493/04B01J31/128B01J2231/70
Inventor 曹正国
Owner 曹正国