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

Patent metadata

Field	Value
Publication number	US-12291498-B2
Application number	US-202418664822-A
Country	US
Kind code	B2
Filing date	May 15, 2024
Priority date	Jun 28, 2019
Publication date	May 6, 2025
Grant date	May 6, 2025

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 from 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.;
passing a high temperature dehydrogenation product upward and out of the primary separation device through an outlet tube, wherein the outlet tube is positioned directly above a body of the primary separation device;
following the exit of the high temperature dehydrogenation product from the primary separation device, combining the high temperature dehydrogenation product with a quench stream by passing the quench stream through a top of the outlet tube 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; 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 quench stream is a gas stream.

3. The method of claim 1 , wherein the primary separation device comprises the body, an inlet, the outlet tube, and a solids discharge dipleg.

4. The method of claim 1 , wherein the primary separation device is a cyclone.

5. The method of claim 1 , wherein the quench stream is passed through a pipe connected to the top of the outlet tube.

6. The method of claim 1 , wherein the quench stream is passed through the top of the outlet tube at a substantially vertical angle.

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

8. The method of claim 7 , wherein the secondary separation device is a cyclone.

Assignees

• Dow Global Technologies Llc

Inventors

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

Classifications

• C07C2523/62

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

• C07C2523/42

  Platinum · CPC title

• C07C2523/08

  of gallium, indium or thallium · CPC title

• C07C11/06

  Propene · CPC title

• C07C11/04

  Ethene · CPC title