Methods for forming light olefins that include use of cooled product as a recycled quench stream

Patent metadata

Field	Value
Publication number	US-11987547-B2
Application number	US-202017622412-A
Country	US
Kind code	B2
Filing date	Jun 12, 2020
Priority date	Jun 28, 2019
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

According to one or more embodiments, a method for forming light olefins may comprise introducing a hydrocarbon feed stream into a reactor, reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product, separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

First claim

The invention claimed is:

1. A method comprising:
introducing a hydrocarbon feed stream into a reactor, wherein the reactor comprises at least one reactor section operating as a fast fluidized, turbulent, or bubbling bed upflow reactor or a dilute phase riser reactor;
reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product having a temperature of at least 550° C., the dehydrogenated product comprising at least a portion of the hydrocarbon feed stream that was not catalytically reacted;
separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, wherein the temperature of the dehydrogenated product and dehydrogenation catalyst in the primary separation device is at least 550° C.;
following the exit of a high temperature dehydrogenation product from the primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, and wherein a temperature of the intermediate temperature dehydrogenation product is at least 10° C. less than a temperature of the high temperature dehydrogenation product, and wherein the temperature of the high temperature dehydrogenation product is about equivalent to the temperature of the high temperature dehydrogenated product; and
cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product, wherein a portion of the cooled dehydrogenation product is utilized as at least a portion of the quench stream.

2. The method of claim 1 , wherein the hydrocarbon feed comprises propane, n-butane, iso-butane, ethane, ethylbenzene, or a combination thereof.

3. The method of claim 1 , wherein the quench stream is at least 300° C. less than the temperature of the high temperature dehydrogenated product.

4. The method of claim 1 , wherein the rate of thermal cracking in the intermediate temperature dehydrogenation product of the portion of the hydrocarbon feed stream that was not catalytically reacted is less than 90% of that in the high temperature dehydrogenated product.

5. The method of claim 1 , further comprising passing the intermediate temperature dehydrogenation product to a secondary separation device where the remainder of the dehydrogenation catalyst is removed from the intermediate temperature dehydrogenation product.

6. The method of claim 1 , wherein the cooled dehydrogenation product has a temperature of less than or equal to 150° C.

7. The method of claim 1 , wherein a heat exchanger and/or liquid quenching system cools the intermediate temperature dehydrogenation product to the cooled dehydrogenation product.

8. The method of claim 1 , wherein one or more of:
the quench stream comprises less than 3 wt. % steam; or the quench stream comprises one or more of ethylene, propylene, or a butene isomer.

9. The method of claim 1 , wherein the dehydrogenation catalyst is a solid and the high temperature dehydrogenated product is a gas.

10. The method of claim 1 , wherein the quench stream is a gas stream.

11. The method of claim 1 , wherein the dehydrogenation catalyst is a gallium and/or platinum catalyst.

12. The method of claim 1 , wherein the reactor comprises an upstream reactor section and a downstream reactor section and the upstream reactor section operates as the fast fluidized, turbulent, or bubbling bed upflow reactor.

13. The method of claim 12 , wherein the downstream reactor section operates as the dilute phase riser reactor.

14. A method comprising:
introducing a hydrocarbon feed stream into a reactor, wherein the reactor comprises at least one reactor section operating as a fast fluidized, turbulent, or bubbling bed upflow reactor or a dilute phase riser reactor;
reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product having a temperature of at least 550° C., the dehydrogenated product comprising at least a portion of the hydrocarbon feed stream that was not catalytically reacted;
separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, wherein the temperature of the dehydrogenated product and dehydrogenation catalyst in the primary separation device is at least 550° C.;
following the exit of a high temperature dehydrogenation product from the primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, wherein a temperature of the intermediate temperature dehydrogenation product is at least 10° C. less than a temperature of the high temperature dehydrogenation product, and wherein the temperature of the high temperature dehydrogenation product is about equivalent to the temperature of the high temperature dehydrogenated product;
passing the intermediate temperature dehydrogenation product to a secondary separation device where the remainder of the dehydrogenation catalyst is removed from the intermediate temperature dehydrogenation product; and
cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product, wherein a portion of the cooled dehydrogenation product is utilized as at least a portion of the quench stream.

15. The method of claim 14 , wherein the hydrocarbon feed comprises propane, n-butane, iso-butane, ethane, ethylbenzene, or a combination thereof.

16. The method of claim 14 , wherein the rate of thermal cracking in the intermediate temperature dehydrogenation product of the portion of the hydrocarbon feed stream that was not catalytically reacted is less than 70% of that in the high temperature dehydrogenated product.

17. The method of claim 14 , wherein the quench stream is a gas stream.

18. The method of claim 14 , wherein the reactor comprises an upstream reactor section and a downstream reactor section and the upstream reactor section operates as the fast fluidized, turbulent, or bubbling bed upflow reactor.

19. The method of claim 18 , wherein the downstream reactor section operates as the dilute phase riser reactor.

Assignees

• Dow Global Technologies Llc

Inventors

• Pretz Matthew T
• Wang Hangyao
• Plauck Anthony
• Mcneeley Adam M

Classifications

• C07C5/3337 Primary

  of the platinum group · CPC title

• C07C2523/08

  of gallium, indium or thallium · CPC title

• C07C2523/42

  Platinum · CPC title

• C07C2523/62

  with gallium, indium, thallium, germanium, tin or lead · CPC title

• C07C5/3335 Primary

  with metals · CPC title