Reactors and systems for oxidative coupling of methane

Patent metadata

Field	Value
Publication number	US-10047020-B2
Application number	US-201414553795-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Nov 27, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

In an aspect, the present disclosure provides a method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C2+ compounds). The method can include mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen and performing an oxidative coupling of methane (OCM) reaction using the third gas stream to produce a product stream comprising one or more C2+ compounds.

First claim

What is claimed is:

1. A method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C 2+ compounds), comprising:
(a) mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen, wherein along a direction that is orthogonal to a direction of flow of said third gas stream, (i) a temperature of said third gas stream varies by less than 10° C., (ii) a ratio of a concentration of said methane to a concentration of said oxygen (CH 4 /O 2 ) in said third gas stream varies by less than 10%, and/or (iii) a flow rate of said third gas stream varies by less than 5%; and
(b) performing an oxidative coupling of methane (OCM) reaction using said third gas stream to produce a product stream comprising one or more C 2+ compounds.

2. The method of claim 1 , further comprising separating said product stream into at least a fourth stream and a fifth stream, wherein said fourth stream has a lower C 2+ concentration than said fifth stream, wherein said fifth stream has a higher C 2+ concentration than said product stream.

3. The method of claim 1 , wherein (a) comprises any two of (i)-(iii).

4. The method of claim 1 , wherein (a) comprises (i), (ii) and (iii).

5. A method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C 2+ compounds), comprising:
(a) in a mixer, mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen, wherein said third gas stream has a composition that is selected such that at most 5% of said oxygen in said third gas stream auto-ignites; and
(b) performing an oxidative coupling of methane (OCM) reaction using said third gas stream to produce a product stream comprising one or more C 2+ compounds.

6. A method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C 2+ compounds), the method comprising:
(a) in a mixer, mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen; and
(b) within a time period less than an auto-ignition delay time of oxygen and methane in said third gas stream, performing an oxidative coupling of methane (OCM) reaction using said third gas stream to produce a product stream comprising one or more C 2+ compounds.

7. A method for producing at least one C 2+ alkene, comprising:
(a) directing methane and an oxidizing agent into a reactor comprising a catalyst unit and a cracking unit downstream of said catalyst unit, wherein said catalyst unit comprises an oxidative coupling of methane (OCM) catalyst that facilitates an OCM reaction;
(b) in said catalyst unit, reacting said methane and said oxidizing agent with the aid of said OCM catalyst to generate at least one OCM product comprising at least one C 2+ compound;
(c) directing said at least one OCM product as part of a hydrocarbon-containing stream through said cracking unit, which hydrocarbon-containing stream comprises at least one C 2+ alkane; and
(d) in said cracking unit, cracking said at least one C 2+ alkane to yield a product stream comprising said at least one C 2+ alkene,
wherein said cracking unit is operated at a (i) hydrocarbon-containing stream residence time and (ii) cracking unit temperature profile selected such that a ratio of C 2+ alkene to C 2+ alkane in said product stream is greater than 0.1.

8. The method of claim 7 wherein said OCM catalyst is a nanowire catalyst.

9. The method of claim 7 , wherein said oxidizing agent is O 2 .

10. The method of claim 7 , wherein said at least one C 2+ compound comprises said at least one C 2+ alkane.

11. The method of claim 7 , wherein in (c), at least a portion of said at least one C 2+ alkane is provided from a source external to said reactor.

12. The method of claim 11 , wherein said source is a natural gas liquids source.

13. The method of claim 7 , wherein said at least one C 2+ alkane comprises a plurality of C 2+ alkanes.

14. The method of claim 13 , wherein said plurality of C 2+ alkanes are each directed into said cracking unit at different locations.

15. The method of claim 7 , wherein said cracking is conducted with the aid of heat generated in said OCM reaction.

16. The method of claim 7 , wherein said cracking unit is operated adiabatically.

17. The method of claim 7 , wherein said hydrocarbon-containing stream is directed through said cracking unit at a residence time that is less than or equal to 1 second.

18. The method of claim 7 , wherein said residence time is less than or equal to 500 milliseconds.

19. The method of claim 7 , wherein said temperature profile is from about 750° C. to 950° C.

20. The method of claim 7 , wherein said cracking unit has an inlet and an outlet downstream of said inlet, where said hydrocarbon-containing stream is directed from said inlet to said outlet, and wherein said inlet is at a temperature from about 880° C. to 950° C. and said outlet is at a temperature from about 750° C. to 880° C.

21. The method of claim 7 , wherein said ratio is greater than 1.

22. The method of claim 21 , wherein said ratio is greater than 3.

23. The method of claim 22 , wherein said ratio is greater than 5.

24. A method for producing at least one C 2+ alkene, comprising:
(a) directing methane and an oxidizing agent into a reactor comprising a catalyst unit and a cracking unit downstream of said catalyst unit, wherein said catalyst unit comprises an oxidative coupling of methane (OCM) catalyst that facilitates an OCM reaction;
(b) in said catalyst unit, reacting said methane and said oxidizing agent with the aid of said OCM catalyst to generate at least one OCM product comprising at least one C 2+ compound;
(c) directing said at least one OCM product as part of a hydrocarbon-containing stream through said cracking unit from an inlet to an outlet at a residence time that is less than 500 milliseconds at a reactor diameter of at least about 12 inches, wherein said inlet is at a temperature from about 800° C. to 950° C. and said outlet is at a temperature from about 700° C. to 950° C., and wherein said hydrocarbon-containing stream comprises at least one C 2+ alkane; and
(d) in said cracking unit, cracking said at least one C 2+ alkane to yield a product stream comprising said at least one C 2+ alkene.

25. A method, comprising:
(a) providing a reactor comprising (i) an OCM section comprising an OCM catalyst that facilitates formation of OCM products from methane and an oxidizing agent, and (ii) a post-bed cracking section located downstream of said OCM catalyst section that facilitates cracking of at least a portion of said OCM products, wherein said OCM section and said post-bed cracking section are integrated in said reactor;
(b) directing said methane and said oxidizing agent to said OCM section;
(c) conducting OCM in said OCM section to generate said OCM products;
(d) mixing said OCM products with a CO 2 stream to produce a cracking stream; and
(e) cracking at least a portion of said OCM products in said cracking stream in said post-bed cracking section.

26. The method of claim 24 , wherein said at least one C 2+ compound comprises said at least one C 2+ alkane.

Assignees

• Siluria Technologies Inc

Inventors

• Cizeron Joel
• Radaelli Guido
• Lakhapatri Satish
• Freer Erik
• Hong Jin Ki
• Mccormick Jarod
• Sheridan David
• Reid Charles
• Pellizzari Roberto
• Weinberger Samuel
• Edwards Justin Dwight

Classifications

• B01J2208/00132

  Tubes · CPC title

• B01J2208/025

  Two or more types of catalyst · CPC title

• B01J8/0214

  in a cylindrical annular shaped bed · CPC title

• B01J8/1827 Primary

  the fluidising gas being a reactant · CPC title

• B01J2208/00902

  Nozzle-type feeding elements · CPC title