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Preparation method of 1,2,4,5-tetramethylbenzene

A technology of durene and tetramethylbenzene, which is applied in the field of preparation of high-purity durene, which can solve the problems of polluting process, immaturity, and incapability of large-scale production, and achieve the effect of simple separation process and environmental friendliness

Active Publication Date: 2021-02-02
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

where from C 10 Separation of durene from aromatics is limited by the supply of raw materials. Trimethylbenzene chloromethylation and disproportionation isomerization cannot be mass-produced due to serious pollution or immature processes. Certain research results, but also not yet large-scale industrial application

Method used

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  • Preparation method of 1,2,4,5-tetramethylbenzene
  • Preparation method of 1,2,4,5-tetramethylbenzene

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preparation example Construction

[0015] The preparation method of the catalyst includes mixing the modified molecular sieve with alumina or its precursor, extruding into a strip, drying and calcining at 400-580°C.

[0016] In the above catalyst preparation method, the alumina precursor may be one or more of aluminum sol, aluminum gel and pseudo-boehmite, preferably pseudo-boehmite. When extruding, it is preferable to add a peptizer into the mixture of modified molecular sieve and alumina or its precursor. The amount of nitric acid is preferably 20-55% of the mass of the mixture. The drying temperature of the extruded product is preferably 90-120° C., and the drying time is preferably 2-6 hours.

[0017] Among the present invention, the preparation method of described modified molecular sieve comprises:

[0018] (1) Impregnate HZSM-5 molecular sieve or HEU-1 molecular sieve with halogen-containing ammonium salt or acid solution at 50-90°C, dry the impregnated solid, and then roast at 450-550°C to obtain a ha...

example 1

[0040] (1) Preparation of modified HZSM-5 molecular sieve

[0041] Take the HZSM-5 molecular sieve whose silica / alumina molar ratio is 42, and use the concentration of 10% by mass of NH 4 F solution was impregnated at 70°C for 1.5 hours under stirring, the impregnated liquid / solid mass ratio was 5:1, the impregnated solid was dried at 110°C for 4 hours, and roasted at 500°C for 6 hours to obtain fluorine-modified HZSM-5 molecular sieve. The F element content is 2.63% by mass (X-ray fluorescence spectrum (XRF) analysis, the same below).

[0042] Get the fluorine-modified HZSM-5 molecular sieve, use La(NO 3 ) 3 The solution was ion-exchanged at 80°C for 1.5 hours, and the liquid / solid mass ratio of ion exchange was 10:1. The ion-exchanged solid was dried at 110°C for 4 hours and calcined at 520°C for 5 hours to obtain fluorine and La-modified HZSM- 5 Molecular sieve a, wherein the F element content is 2.63% by mass, and the La element content is 1.83% by mass.

[0043] (2) P...

example 2

[0046] (1) Preparation of modified HEU-1 molecular sieve

[0047] Get the HEU-1 molecular sieve that the silica / alumina molar ratio is 40, use the NH that concentration is 10 mass % 4 The F solution was impregnated at 70°C for 1.5 hours under stirring, the impregnated liquid / solid mass ratio was 5:1, the impregnated solid was dried at 110°C for 4 hours, and roasted at 500°C for 6 hours to obtain fluorine-modified HEU-1 molecular sieves. Among them, the F element content is 2.75% by mass.

[0048] Get the fluorine-modified HEU-1 molecular sieve, use Ce(NO 3 ) 3 The solution was ion-exchanged at 80°C for 1 hour, and the liquid / solid mass ratio of ion exchange was 10:1. The ion-exchanged solid was dried at 110°C for 4 hours and calcined at 520°C for 5 hours to obtain fluorine and Ce-modified HEU- 1 Molecular sieve b, wherein the F element content is 2.75% by mass, and the Ce element content is 1.28% by mass.

[0049] (2) Preparation of catalyst

[0050] Mix the modified HEU-...

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Abstract

A preparation method of 1,2,4,5-tetramethylbenzene comprises the steps of: mixing unsym-trimethylbenzene and methanol, carrying out heating gasification, feeding the gasification product into an alkylation reactor, carrying out an alkylation reaction by contact with a catalyst under conditions of a temperature of 280-450 DEG C and a pressure of 0.1-3.0 MPa, carrying out gas-liquid separation on the product flowing out of the alkylation reactor, discharging the water phase, discharging the gas-phase hydrocarbon component in the obtained oil phase, enabling the liquid-phase hydrocarbon componentto enter a rectification separation system to separate light hydrocarbons below C6, methylbenzene, dimethylbenzene, trimethylbenzene, tetramethylbenzene and aromatic hydrocarbon fractions above C11,wherein the content of 1,2,4,5-tetramethylbenzene in the tetramethylbenzene fraction is not lower than 96% by mass. According to the method, a high-purity durene product can be obtained only through rectification, crystallization, separation and purification are not needed, the separation process is simple, and the production efficiency is high.

Description

technical field [0001] The invention is a method for preparing durene by alkylation, in particular, a method for preparing high-purity durene through alkylation reaction of trimethylene and methanol. Background technique [0002] Durene is an important fine chemical raw material, which is mainly used to prepare pyromellitic dianhydride and polyimide, among which polyimide has excellent mechanical properties, thermal stability and chemical corrosion resistance. Aerospace, missiles, supersonic aircraft, atomic energy industry and electromechanical industry and other fields are widely used. [0003] There are two production methods of durene: physical separation method and chemical synthesis method. The physical separation method is from C 10 The separation of mesitylene from aromatics is the main production method adopted at home and abroad; the chemical synthesis methods mainly include isomerization of mesitylene, disproportionation isomerization of mesitylene, chloromethyla...

Claims

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Application Information

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IPC IPC(8): C07C2/86C07C15/02
CPCC07C2/864C07C15/02Y02P20/584
Inventor 李林玥杜鹏朱宁葸雷
Owner CHINA PETROLEUM & CHEM CORP
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