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Method for preparing methylhexahydrophthalic anhydride by means of continuous hydrogenation

A technology of methyl hexahydrophthalic anhydride and methyl tetrahydrophthalic anhydride, which is applied in the field of continuous hydrogenation of methyl tetrahydrophthalic anhydride to prepare methyl hexahydrophthalic anhydride, can Solve the problems of poor product quality stability, inability to recycle, and large floor space, and achieve the effects of shortening hydrogenation time, small floor space, and small heat loss

Active Publication Date: 2017-08-25
河南惠成新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method produces methyl hexahydrophthalic anhydride, the equipment occupies a large area, the device cost is high, and the product quality stability is poor. The hydrogenation temperature is 100-140°C, the pressure needs to be above 8MPa, and the hydrogenation time needs to be 15-20h. After the hydrogenation is completed, the distillation operation is carried out directly, and the catalyst is mixed with a large amount of after-distillate to become waste residue, which cannot be recycled and causes environmental pollution

Method used

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  • Method for preparing methylhexahydrophthalic anhydride by means of continuous hydrogenation
  • Method for preparing methylhexahydrophthalic anhydride by means of continuous hydrogenation

Examples

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Embodiment 1

[0019] Embodiment 1: industrial application

[0020] According to the present invention, the production process for preparing methyl hexahydrophthalic anhydride by continuous hydrogenation of methyltetrahydrophthalic anhydride as raw material is characterized in that three-stage split-tube fixed-bed reactors 17 and 19 are used , 21 carry out continuous hydrogenation in circulation, and each split-tube fixed-bed reactor is connected in series by raw material circulation pumps 16, 18, 20; the inside of the split-tube fixed-bed reactor adopts a split-tube structure. Composite solid catalyst 8 is filled, and coal medium is heated in the shell side; hydrogen enters in parallel from the bottom 5 of the split-tube reactors at all levels, and returns to the hydrogen compressor 23 through the outlet 6 after passing through the split tubes. The raw material methyltetrahydrophthalic anhydride is transported to the upper part of the primary reactor 17 through the primary high-pressure cir...

Embodiment 2

[0025] Example 2: actual production application

[0026] 100 parts of Raney nickel and 20 parts of palladium / alumina were dried in a double-cone dryer and mixed for 1.5 hours. The split-tube fixed-bed reactor removes the upper head, and the hydrogen inlet 5 at the bottom of the reactor has a flow rate of 5m 3 / h of nitrogen, the split tube was purged for 10 minutes, and the nitrogen flow rate was adjusted to 1m 3 / h, the pre-mixed and dried catalyst is filled into the split tube through the upper part of the kettle body, and the bulk density is 0.1-0.5g / ml. After filling, connect the upper head. The nitrogen flow rate is adjusted to 5m 3 / h, continue purging for 10min, and stop nitrogen flow.

[0027]Regulate the hydrogen pressure to be 6MPa, and the hydrogen enters in parallel from the bottom inlet 5 of the reactors 17, 19, 21, and the unreacted hydrogen returns to the hydrogen compressor 23 through the outlet 6 on the top of the reactors 17, 19, 21. Control the reaction...

Embodiment 3

[0028] Example 3: actual production application

[0029] 100 parts of Raney nickel, 40 times of palladium / alumina, dried in a double-cone dryer and mixed for 1.5 hours. The split-tube fixed-bed reactor removes the upper head, and the hydrogen inlet 5 at the bottom of the reactor has a flow rate of 5m 3 / h of nitrogen, the split tube was purged for 10 minutes, and the nitrogen flow rate was adjusted to 1m 3 / h, the pre-mixed and dried catalyst is filled into the split tube through the upper part of the kettle body, and the bulk density is 0.1-0.5g / ml. After filling, connect the upper head. The nitrogen flow rate is adjusted to 5m 3 / h, continue purging for 10min, and stop nitrogen flow.

[0030] Regulate the hydrogen pressure to be 3MPa. The hydrogen enters in parallel from the bottom inlet 5 of the reactors 17, 19, and 21, and the unreacted hydrogen returns to the hydrogen compressor 23 through the outlet 6 on the top of the reactors 17, 19, and 21. The reaction temperatu...

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Abstract

The invention discloses a method for preparing methylhexahydrophthalic anhydride by means of continuous hydrogenation and belongs to the field of organic chemicals. A three-level split-tube fixed bed reactor is adopted for circularly continuous hydrogenating; a split-tube type structure is adopted in the split-tube fixed bed reactor; a solid catalyst is arranged between tube passes; a heat medium is arranged in a shell pass; hydrogen respectively enters from the bottom of each level of split-tube fixed bed reactor in parallel; unreacted hydrogen passes by each split tube and then returns to a hydrogen compressor from the upper part of the reactor; the raw material, methyltetrahydrophthalic anhydride, gradually passes by a high pressure pipe pump, is conveyed to the upper part of the split-tube reactor and is sprayed by a distributor located at the top in the reactor so as to be uniformly distributed on the surface of the solid catalyst and react with hydrogen; after circular reaction through the three-level reactor, the hydrogenating conversion rate is close to 100%. According to the method, the production of methylhexahydrophthalic anhydride by means of continuous hydrogenation is realized, the technical process is clean and the catalyst is reused.

Description

technical field [0001] The invention belongs to the field of organic chemical industry, and relates to a production method for continuous hydrogenation of acid anhydride products, in particular to a method for continuously hydrogenating methyl tetrahydrophthalic anhydride to prepare methyl hexahydrophthalic anhydride. Background technique [0002] Methylhexahydrophthalic anhydride (Methylhexahydrophthalic anhydride, MeHHPA for short, CAS25550-51-0) is an alicyclic acid anhydride, which is widely used because of its excellent physical and chemical properties. As a non-toxic epoxy resin curing agent with excellent performance, it can form a three-dimensional network structure after curing with epoxy resin. After curing at high temperature, it has excellent weather resistance, heat resistance, water resistance, corrosion resistance and dielectric properties. Excellent; it is suitable for impregnating large components, but also for pouring, bonding, laminating, etc. Widely used...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/89B01J8/00B01J8/02B01J8/04
CPCB01J8/0015B01J8/0242B01J8/0285B01J8/04B01J2219/00051B01J2219/00162C07D307/89
Inventor 张鹏可王永桥于慧娟郑玉奇田维波杨振强陈辉杨瑞娜王中锋
Owner 河南惠成新材料有限公司
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