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Method for continuous preparing 1,2,-propylene glycol

A technology of propylene glycol and propylene oxide, applied in 1 field, can solve problems such as difficult catalyst recovery and equipment corrosion

Inactive Publication Date: 2007-05-02
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the propylene oxide catalytic hydration process can improve the selectivity of 1,2-propanediol, it also brings about the difficulty of catalyst recovery and the corrosion of equipment

Method used

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  • Method for continuous preparing 1,2,-propylene glycol
  • Method for continuous preparing 1,2,-propylene glycol
  • Method for continuous preparing 1,2,-propylene glycol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] CO control 2 The mol ratio of / propylene oxide is 1.1: 1, enters synthesis reactor, the amount of catalyzer tetraethylamine bromide is 1% of propylene oxide weight, 180 ℃ of reaction temperature, 1 hour reaction times, the purity 99.5% of propylene carbonate , yield 99.5% (calculated as propylene oxide)

[0022] Regulate the mol ratio 2: 1 of water / propylene carbonate, enter hydrolysis reactor, sodium carbonate is catalyzer, the consumption of sodium carbonate is 1.5% of propylene carbonate and water gross weight, temperature of reaction remains on 60 ℃, reacts 1.5 hours, Propylene carbonate yielded a conversion of 99.5% and a selectivity of 1,2-propanediol of 100%.

[0023] The rectification tower is a packed tower with 20 theoretical plates, reflux ratio of 3.0, tower inner pressure of 0.018Mpa, tower bottom temperature of 160°C, purity of 1,2-propanediol over 99.5%, and rectification yield of 97%. The total yield of 1,2-propanediol was 96.0% (calculated as propylen...

Embodiment 2

[0025] CO control 2 The mol ratio of / propylene oxide is 1.05: 1, enters synthesis reactor, the consumption of catalyst KI / PEG is 1% of propylene oxide weight, 150 ℃ of reaction temperatures, 1 hour reaction time, the purity 99.5% of propylene carbonate, yield Rate 99.5% (based on propylene oxide)

[0026] Regulate the mol ratio of water / propylene carbonate 1.5: 1, enter hydrolysis reactor, potassium hydroxide is catalyzer, the consumption of potassium hydroxide is 1.0% of propylene carbonate and water gross weight, temperature of reaction remains on 80 ℃, reaction 1.0 100% conversion of propylene carbonate and 100% selectivity to 1,2-propanediol were obtained in 1 hour.

[0027] The rectification tower is a tray tower with 30 theoretical plates, reflux ratio of 2.5, tower inner pressure of 0.018Mpa, tower bottom temperature of 165°C, 1,2-propanediol purity of over 99.5%, and rectification yield of 98%. The total yield of 1,2-propanediol was 97.5% (calculated as propylene ox...

Embodiment 3

[0029] CO control 2 The mol ratio of / propylene oxide is 1.05: 1, enters synthesis reactor, the amount of catalyst KI / PEG is 1% of propylene oxide weight, 150 ℃ of reaction temperatures, 1 hour reaction time, the purity 99.5% of propylene carbonate, yield Rate 99.5% (based on propylene oxide)

[0030] Regulate the mol ratio of water / propylene carbonate 5: 1, enter hydrolysis reactor, calcium hydroxide is catalyzer, and the consumption of calcium hydroxide is 1.0% that is propylene carbonate and water gross weight, and temperature of reaction remains on 140 ℃, reaction In 30 minutes, 100% conversion of propylene carbonate and 100% selectivity to 1,2-propanediol were obtained.

[0031] The rectification tower is a tray tower with 30 theoretical plates, reflux ratio of 2.5, tower inner pressure of 0.018Mpa, tower bottom temperature of 165°C, 1,2-propanediol purity of over 99.5%, and rectification yield of 98%. The total yield of 1,2-propanediol was 97.5% (calculated as propylen...

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Abstract

This invention relates to a preparation of 1,2- propylene glycol, the main steps are: In the condition that catalyst 1 is existent, first epoxypropane and carbon dioxide are carred out esterification to produce propylene carbonate ester, then propylene carbonate ester processes lytic response to produce target matter in the condition that catalyst 2 is existent and temperature is 30- 180DEG C. This invention overcomes the flaw of low reactive selectivity that exists in present technology of direct pressurizing aquation of epoxypropane.

Description

technical field [0001] The invention relates to a preparation method of 1,2-propanediol. Background technique [0002] 1,2-Propanediol (referred to as PG) is a widely used basic chemical raw material. At present, the preparation of PG mainly adopts the direct pressurized hydration process of propylene oxide (PO) (Shijiazhuang Chemical Industry, 1996, 3:33-37.), the defect of this process is that the selectivity of the reaction is not high, that is, the hydration of propylene oxide In addition to generating the target product (PG), the reaction also produces by-products propylene glycol (DPG) and dipropylene glycol (TPG) at the same time, and the overall yield is 84.4%. The reaction formula of PO direct pressurized hydration process is as follows: [0003] Main response: [0004] [0005] side effects: [0006] [0007] For example, in order to improve the reaction selectivity of PO direct pressurized hydration process, CN 86107894 discloses the synthetic technique ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C31/20C07C29/12
Inventor 方云进李殷
Owner EAST CHINA UNIV OF SCI & TECH