Reactors and systems for oxidative coupling of methane

Patent metadata

Field	Value
Publication number	US-11008265-B2
Application number	US-201916538012-A
Country	US
Kind code	B2
Filing date	Aug 12, 2019
Priority date	Jan 9, 2014
Publication date	May 18, 2021
Grant date	May 18, 2021

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 producing hydrocarbon compounds including two or more carbon atoms (C 2+ compounds), the method comprising:
(a) performing an oxidative coupling of methane (OCM) reaction in an OCM reactor to produce an OCM effluent comprising carbon dioxide (CO 2 ), hydrogen (H 2 ), one or more C 2+ compounds, and methane (CH 4 );
(b) separating the OCM effluent into (i) a first stream comprising at least some of the one or more C 2+ compounds and (ii) a second stream comprising carbon monoxide (CO), CO 2 , H 2 , and CH 4 ;
(c) methanating the second stream to produce a first OCM reactor feed comprising CH 4 formed from the H 2 and CO and/or CO 2 in the second stream;
(d) methanating a third stream comprising CH 4 and H 2 to produce a second OCM reactor feed comprising CH 4 , which third stream is from an ethylene cracker; and
(e) directing the first and second OCM reactor feeds to the OCM reactor.

2. The method of claim 1 , wherein the second stream and the third stream are methanated in a single methanation reactor.

3. The method of claim 1 , further comprising providing at least a portion of the first stream to the ethylene cracker.

4. The method of claim 3 , wherein the at least the portion of the first stream is provided to a gas compressor or a fractionation unit of the ethylene cracker.

5. The method of claim 1 , wherein the third stream is the overhead stream of a demethanizer unit of the ethylene cracker.

6. The method of claim 1 , wherein the separating in (b) is performed at least in part in a pressure swing adsorption (PSA) unit.

7. The method of claim 1 , wherein the separating in (b) is performed at least in part with a CO 2 removal system or a process gas dryer.

8. The method of claim 1 , wherein the OCM effluent is compressed prior to (b).

9. The method of claim 1 , further comprising feeding oxygen (O 2 ) as an oxidizing agent to the OCM reactor, which O 2 takes part in the OCM reaction.

10. The method of claim 1 , wherein the OCM effluent comprises carbon monoxide (CO) that is converted into CH 4 in (c).

11. The method of claim 1 , wherein the OCM reaction further reacts CH 4 from natural gas to achieve additional ethylene production.

12. An oxidative coupling of methane (OCM) system for production of hydrocarbon compounds including two or more carbon atoms (C 2+ compounds), comprising:
(a) an OCM subsystem that (i) takes as input a feed stream comprising methane (CH 4 ) and an oxidizing agent, and (ii) generates a product stream comprising C 2+ compounds from the CH 4 and the oxidizing agent;
(b) a separation subsystem fluidically coupled to the OCM subsystem that separates the product stream into (i) a first stream comprising C 2+ compounds and (ii) a second stream comprising hydrogen (H 2 ) and carbon dioxide (CO 2 ) and/or carbon monoxide (CO);
(c) a methanation subsystem fluidically coupled to the second stream and to the OCM subsystem, wherein the methanation subsystem converts H 2 and CO 2 and/or CO into CH 4 ; and
(d) an ethylene cracker subsystem fluidically coupled to the methanation subsystem that provides CH 4 , H 2 , CO 2 , and/or CO to the methanation subsystem.

13. The system of claim 12 , wherein the methanation subsystem provides CH 4 to the OCM subsystem.

14. The system of claim 12 , wherein the ethylene cracker subsystem comprises a demathanizer that provides CH 4 , H 2 , CO 2 , and/or CO to the methanation subsystem.

15. The system of claim 12 , wherein the first stream is fluidically coupled to the ethylene cracker subsystem, and the ethylene cracker subsystem is configured to fractionate the first stream.

16. The system of claim 12 , wherein the separation subsystem comprises a pressure swing adsorption (PSA) unit.

17. The system of claim 12 , wherein the OCM subsystem reacts CH 4 from natural gas with the oxidizing agent in an OCM reaction.

18. The system of claim 12 , wherein the oxidizing agent comprises O 2 .

19. The system of claim 18 , wherein the O 2 is generated from air.

20. The system of claim 12 , wherein the OCM subsystem comprises at least one OCM reactor.

21. The system of claim 20 , wherein the OCM subsystem comprises at least one post-bed cracking unit within the at least one OCM reactor or downstream of the at least one OCM reactor, which post-bed cracking unit is configured to convert at least a portion of alkanes in the product stream to alkenes.

Assignees

• Lummus Technology Inc

Inventors

• Rafique Humera A
• Vuddagiri Srinivas
• Radaelli Guido
• Mccormick Jarod
• Duggal Suchia
• Cizeron Joel

Classifications

• F25J2270/06

  with multiple gas expansion loops · CPC title

• F25J2240/02

  Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream · CPC title

• F25J2230/08

  Cold compressor, i.e. suction of the gas at cryogenic temperature and generally without afterstage-cooler · CPC title

• F25J2270/04

  Internal refrigeration with work-producing gas expansion loop · CPC title

• F25J2200/76

  Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle · CPC title