Production technique of benzenetetracarboxylic dianhydride by catalyzing carrier-type polyoxometalates

A technology of pyromellitic dianhydride and polyoxometalate, which is applied in the field of carrier-type polyoxometalate catalyzed production of pyromellitic dianhydride, and can solve the problems of difficulty, pollution of the production process of pyromellitic anhydride, and high production cost problem, to achieve the effect of low production cost, avoid equipment corrosion, and reduce raw material cost

Inactive Publication Date: 2007-09-19
NORTHEAST NORMAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The invention discloses a process for producing pyromellitic dianhydride catalyzed by a carrier-type polyoxometalate, which overcomes the shortcomings

Method used

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  • Production technique of benzenetetracarboxylic dianhydride by catalyzing carrier-type polyoxometalates
  • Production technique of benzenetetracarboxylic dianhydride by catalyzing carrier-type polyoxometalates

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Effect test

Embodiment 1

[0019] Melt durene at 190°C in the material tank, preheat and send it to the mixer for vaporization at 200°C, the feed concentration is 17.0-17.5g / m 3 , mixed with air, the mixed gas enters the fixed-bed reactor for oxidation, and at 320°C, the catalyst is polymetallic oxo-acid (POM) loaded and fixed on the catalytic bed, poly-metallic oxo-acid: (C 21 h 37 NH) 3 h 3 AsMo 9 V 3 o 40 / SiO 2 The mass ratio to durene is 5‰, and the space velocity is 6500h -1 carry out the oxidation reaction. The gas after the reaction is cooled and solidified in the trap to obtain crude pyromellitic dianhydride.

Embodiment 2

[0021] Melt durene at 193°C in the feed tank, preheat and send it to the mixer for vaporization at 205°C, the feed concentration is 15.5g / m 3 , mixed with air, the mixed gas enters the fixed bed reactor for oxidation, and at 340°C, the catalyst is polyoxometalate (POM) loaded and fixed on the catalytic bed, polyoxometalate (C 21 h 37 NH) 3 h 2 AsMo 10 V 2 o 40 / SiO 2 The mass ratio to durene is 8‰, and the space velocity is 4500h -1 carry out the oxidation reaction. The gas after the reaction is cooled and solidified in the trap to obtain crude pyromellitic dianhydride.

Embodiment 3

[0023] Melt durene at 195°C in the material tank, preheat and send it to the mixer for vaporization at 210°C, the feed concentration is 19.5g / m 3 , mixed with air, the mixed gas enters the fixed bed reactor for oxidation, and at 320°C, the catalyst is polyoxometalate (POM) loaded and fixed on the catalytic bed, polyoxometalate (C 21 h 17 NH) 3 HAsMo 11 VO 40 / SiO 2 The mass ratio to durene is 6‰, and the space velocity is 6500h -1 carry out the oxidation reaction. The gas after the reaction is cooled and solidified in the trap to obtain crude pyromellitic dianhydride.

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Abstract

The invention discloses a craft for producing pyromellitic dianhydride catalyzed by a carrier-type poly-oxometalate, including melting the pyromellitic dianhydride by the groove, feeding to the mixing machine for evapouration after pre-heating with a feed concentration of 15.0-19.5g/m3, mixing with the air, entering into the fixed bed reactor for a oxidation, oxidating with an airspeed of 4500-6500 h-1, cooling the produced air, then condensing in the collector, getting coarse pyromellitic dianhydride. At 300-340 DEG C, the catalyzer is mostly poly-oxometalate which is fixed on the catalyst bed after loading. The mass ratio of the catalyzer to pyromellitic dianhydride is 0.2-1%. The invention has the durene in the C10 heavy aromatics as raw material, produces the pyromellitic dianhydride by oxidation in air, makes the C10 heavy aromatics be with a higher added value, uses the current resource and industrial equipments as more as possible, exploits the catalysis and synthesis path of the pyromellitic dianhydride. The invention has a low pollution and production cost, a wide development prospect and is suitable for commercial process.

Description

technical field [0001] The invention relates to a new production process of pyromellitic dianhydride, in particular provides a process for producing pyromellitic dianhydride catalyzed by a carrier-type polyoxometalate, and belongs to the technical field of chemical product preparation. Background technique [0002] The pyromellitic dianhydride involved in the present invention is abbreviated as Pyromellitic Dianhydride, which is an important chemical product and raw material with high added value, and its most important use is as a raw material for synthesizing polyimide. [0003] There are many production methods for pyromellitic dianhydride. Due to the different raw materials used, the selected process routes are different; even if the same raw material is used, there are many production processes. For example: PMDA is prepared by xylene chloromethylation, which is to separate dichloromethylxylene after reacting 2,4-xylene, which accounts for 98% of the meta-para position,...

Claims

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Application Information

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IPC IPC(8): C07D493/04B01J31/02B01J31/34
Inventor 张宏张景萍王爱霞
Owner NORTHEAST NORMAL UNIVERSITY
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