Method for preparing propylene oxide by means of direct epoxidation of propylene

Patent metadata

Field	Value
Publication number	US-12534445-B2
Application number	US-202118005001-A
Country	US
Kind code	B2
Filing date	Jan 26, 2021
Priority date	Jul 10, 2020
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A method of preparing epoxypropane by direct epoxidation of propylene includes the steps of contacting a mixed gas consisting of a reaction feed gas and a diluent gas with a catalyst to carry out reaction under reaction conditions of propylene epoxidation to prepare epoxypropane. The reaction feed gas contains propylene, oxygen gas and hydrogen gas while at least a portion of the diluent gas is a gaseous olefin. Using gaseous olefin as at least a portion of the diluent gas to perform propylene epoxidation can significantly extend service life of the catalyst, effectively reduce the used amount of diluent gas, and improve the reaction selectivity and propylene conversion rate.

First claim

The invention claimed is:

1 . A method of performing direct epoxidation of propylene comprising:
contacting a mixed gas consisting of a reaction feed gas and a diluent gas with a catalyst to carry out propylene epoxidation to produce epoxypropane, wherein the reaction feed gas comprises propylene, oxygen gas and hydrogen gas, at least a portion of the diluent gas is a gaseous olefin selected from C 2 -C 4 olefins and mixtures thereof, and a proportion of oxygen gas in the mixed gas is more than 14 vol. %.

2 . The method of claim 1 , wherein the proportion of the diluent gas in the mixed gas is less than 60 vol. %.

3 . The method of claim 1 wherein the propylene epoxidation is carried out in the presence of an alkali, which is an alkaline gas, or an alkaline substance that is gaseous under the reaction conditions.

4 . The method of claim 3 , wherein the alkali is a compound having a lone pair of electrons and/or a substance capable of accepting protons;
wherein, the compound having a lone electron pair is at least one selected from the group consisting of ammonia, pyridine, hydrazine, cyanogen, amine, alcohol, ether and thiol; and/or the substance capable of accepting protons is at least one selected from the group consisting of Cl − , [Al(H 2 O) 5 OH] 2+ , Ac − , HPO 4 2− and PO 4 3- .

5 . The method of claim 3 , wherein the alkali is used in the mixed gas in an amount of 1-10,000 ppm.

6 . The method of claim 3 , wherein the diluent gas is propylene.

7 . The method of claim 6 , wherein the proportion of oxygen gas in the mixed gas is more than 16 vol. %.

8 . The method of claim 6 , wherein the proportion of the diluent gas in the mixed gas is less than 57.5 vol. %.

9 . The method of claim 1 , wherein the propylene epoxidation is carried out in a tubular reactor or a microchannel reactor.

10 . The method of claim 9 , wherein one or more flow perturbing members are disposed in the microchannel reactor;
wherein the flow perturbing member has a shape selected from the group consisting of heart, diamond, S-shape, triangle, rectangle, square, circle, crossed finger type, spiral, V-shape, T-shape and C-shape; alternatively, the microchannel reactor is a spiral microchannel reactor.

11 . The method of claim 1 , wherein the catalyst is a supported metal catalyst comprising a carrier and an active metal component; the active metal component is at least one selected from the group consisting of gold, silver, copper, ruthenium, palladium, platinum, rhodium, cobalt, nickel, tungsten, bismuth, molybdenum and oxides thereof; the carrier is at least one selected from the group consisting of carbon black, activated carbon, silica, alumina, ceria and zeolite; the content of the active metal component in terms of the metal element in the catalyst is 0.01-50 wt %, based on the total weight of the catalyst.

12 . The method of claim 1 , wherein the catalyst is filled in the reactor in a form of combining with an inert filler;
wherein, the inert filler is at least one selected from the group consisting of silica sand, Al 2 O 3 , porous silica gel and ceramic ring; wherein, the inert filler is used in an amount of 1-200 parts by weight with respect to 1 part by weight of the catalyst; wherein, the catalyst and the inert filler are filled in the reactor in a layered stacking manner.

13 . The method of claim 1 , wherein the reaction conditions of propylene epoxidation comprise: a reaction temperature of 20-300° C.; a reaction pressure of 0-5 MPa; and a volumetric hourly space velocity of 500-30,000 mL g cat −1 h −1 .

14 . The method of claim 1 , wherein the method further comprises a step of preheating the mixed gas prior to contacting the mixed gas with the catalyst.

15 . The method of claim 1 , wherein the propylene epoxidation is performed in the absence of a solvent.

16 . The method of claim 1 , wherein the method further comprises:
blending a first feed gas and a second feed gas to obtain the mixed gas; wherein the first feed gas comprises oxygen gas, the second feed gas comprises hydrogen gas, the first feed gas and/or the second feed gas contain propylene, at least one of the first feed gas and the second feed gas further comprises a gaseous olefin.

17 . The method of claim 16 , wherein the concentration of oxygen gas in the first feed gas and the mixed gas each independently satisfies the following form

X

O
⁢
2

≤

1
-

1

∑

X
n

N
n

+

X
propylene

N
propylene

+

X
hydrogen

N
hydrogen

,

or

Formula
⁢

(
1
)

X

O
⁢
2

≥

1
-

1

∑

X
n

L

Assignees

• China Petroleum & Chem Corp
• Sinopec Res Institute Of Safety Engineering Co Ltd

Inventors

• Zhao Chenyang
• Sun Bing
• Zhu Hongwei
• Feng Junjie
• Wang Lin
• Yang Zhe
• Xu Wei
• Jiang Huiyun
• An Fei
• Jin Yan

Classifications

• C07D301/10 Primary

  with catalysts containing silver or gold · CPC title

• C07D303/04

  containing only hydrogen and carbon atoms in addition to the ring oxygen atoms · CPC title

• C07D301/08 Primary

  in the gaseous phase · CPC title