Method and apparatus for preparing epoxypropane by catalyzing propone epoxidation at supercritical condition

Inactive Publication Date: 2009-06-17
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The diffusion performance of the reactant system is not good, and the products and by-products in the TS-1 pores cannot be removed in time, resulting in the deactivation of the catalyst; also, only TS-1 with small grains can have the corresponding catalytic activity, showing grain Size effect, and the small crystal grains bring the problem of separation and recovery of the catalyst. In addition, in the synthesis process of small grain TS-1, it is necessary to use expensive tetrapropylammonium hydroxide (TPAOH) as a template agent, and the cost is high, while Cheap tetrapropylammonium bromide (TPABr) as a template can only synthesize TS-1 with larger grain size
In short, the application of TS-1 is limited by the factors of diffusion kinetics. It is imperative to improve the diffusion and mass transfer performance of the reaction system by introducing new technologies to solve the problems of easy deactivation and separation and recovery of catalysts.

Method used

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  • Method and apparatus for preparing epoxypropane by catalyzing propone epoxidation at supercritical condition

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] TS-1 under traditional conditions catalyzes the epoxidation of propylene. The catalyst uses TPAOH as a template to synthesize small grain TS-1 (particle size is 0.2 μm), the dosage is 0.3wt%, the pressure of propylene is 0.4MPa, hydrogen peroxide The concentration is 1mol%, the concentration of co-solvent methanol is 4wt%, the reaction temperature is 40°C, no carbon dioxide is used, the conversion rate of hydrogen peroxide is 85%, the selectivity of propylene oxide is 89%, and the yield of propylene oxide is 75.6%.

Embodiment 2

[0018] TS-1 under traditional conditions catalyzes the epoxidation of propylene. The catalyst uses TPABr as a template to synthesize large-grain TS-1 (particle size is 1 μm), the dosage is 0.3wt%, the pressure of propylene is 0.4MPa, and the concentration of hydrogen peroxide The concentration of the co-solvent methanol is 4wt%, the reaction temperature is 40°C, and no carbon dioxide is used. The conversion of hydrogen peroxide was 79%, the selectivity of propylene oxide was 48%, and the yield of propylene oxide was 38%.

Embodiment 3

[0019] Embodiment 3: TS-1 catalyzes propylene epoxidation under supercritical conditions, and the catalyst adopts TPABr as the large-grain TS-1 (particle diameter is 1 μ m) synthesized by template agent, and consumption is 0.3wt%, and propylene pressure is 0.65MPa , the concentration of hydrogen peroxide is 1mol%, the concentration of co-solvent methanol is 4wt%, the pressure of carbon dioxide is 7.6MPa, and the reaction temperature is 40°C. Reaction result: the conversion rate of hydrogen peroxide is 98%, the selectivity of propylene oxide is 92%, and the yield of propylene oxide is 90.2%.

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Abstract

The invention discloses a method and a device for preparing propylene oxide by catalyzing propylene cycle to be oxidized under supercritical conditions, and belongs to petrochemical material preparation technology. The method comprises the following steps: using supercritical carbon dioxide as a reaction medium, adopting a catalyst with large particle diameter, adding the catalyst into a reactor, then adding gas reactant propylene into a mixer, adding an aqueous solution of liquid reactant hydrogen peroxide and cosolvent methanol into the mixer, and introducing carbon dioxide into the mixer to be mixed with the aqueous solution of the propylene and the hydrogen peroxide and the cosolvent methanol which then react in the reactor to obtain a reaction product of the propylene oxide. The supercritical carbon dioxide has good solubility for propylene gas so as to increase concentration of the reactant in the reaction system, so the supercritical carbon dioxide is favorable for reaction. The supercritical carbon dioxide has excellent diffusivity, so that the product can be shifted out of a molecular sieve in time to reduce generation of secondary reaction, so as to retard inactivation of the catalyst. The TS-1 catalyst with large particle diameter overcomes the defect of difficult separation of the product and the catalyst.

Description

technical field [0001] The invention belongs to the preparation technology of petrochemical raw materials, in particular to the use of supercritical carbon dioxide (SCCO 2 ) as its reaction medium, using tetrapropylammonium bromide (TPABr) as a template to synthesize large-size titanium-silicon molecular sieve TS-1 as a catalyst, the whole reaction is carried out in a supercritical state under a supercritical condition that catalyzes propylene A method and device for preparing propylene oxide by epoxidation. Background technique [0002] Propylene oxide (PO) is an important petrochemical raw material. The traditional preparation method of chlorohydrin method has problems of equipment corrosion and environmental pollution. The co-oxidation method requires huge equipment investment and many co-products. With titanium silicate molecular sieve (TS-1) as catalyst, H 2 o 2 The catalytic reaction as an oxidant has the advantages of mild conditions, rapid reaction, high selectivi...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C07D301/12C07D303/04B01J29/89
CPCY02P20/52Y02P20/54
Inventor吴玉龙杨明德陈镇刘吉党杰胡湖生龙亮秦岭
OwnerTSINGHUA UNIV