Oxidative coupling of methane methods and systems

Patent metadata

Field	Value
Publication number	US-2021024439-A1
Application number	US-202017060506-A
Country	US
Kind code	A1
Filing date	Oct 1, 2020
Priority date	Mar 17, 2015
Publication date	Jan 28, 2021
Grant date	—

Abstract

The present disclosure provides natural gas and petrochemical processing systems including oxidative coupling of methane reactor systems that integrate process inputs and outputs to cooperatively utilize different inputs and outputs of the various systems in the production of higher hydrocarbons from natural gas and other hydrocarbon feedstocks.

First claim

What is claimed is:

1 . A system for producing propylene, comprising:
an oxidative coupling of methane (OCM) reactor that receives methane (CH 4 ) and oxygen (O 2 ) and reacts the CH 4 and the O 2 to yield an OCM product stream comprising hydrocarbon compounds containing at least two carbon atoms (C 2+ compounds) including ethylene; a separations unit that receives the OCM product stream and yields an ethylene stream comprising ethylene from the OCM product stream; a dimerization reactor that receives a first portion of ethylene from the ethylene stream and reacts the ethylene in a dimerization reaction to yield a butene stream comprising butene compounds; a C 4 separations unit that receives the butene stream and yields a butene-2 stream comprising butene-2 from the butene stream; and a metathesis reactor that receives the butene-2 stream and a second portion of ethylene from the ethylene stream and reacts the butene-2 and the ethylene to yield a metathesis product stream comprising C 2+ compounds including propylene.

2 . The system of claim 1 , further comprising a C 2 separations unit that receives the metathesis product stream and separates the metathesis product stream to yield a C 2 stream comprising C 2 compounds and a C 3+ stream comprising C 3+ compounds including propylene.

3 . The system of claim 2 , wherein the separations unit receives the C 2 stream.

4 . The system of claim 2 , further comprising a C 2 splitter that receives the C 2 stream and separates the C 2 stream to yield an ethylene stream and an ethane stream.

5 . The system of claim 4 , further comprising a hydrogenation unit that receives the C 2 stream prior to the C 2 stream being received by the C 2 splitter.

6 . The system of claim 4 , wherein the OCM reactor is in fluid communication with the C 2 splitter and receives the ethane stream from the C 2 splitter.

7 . The system of claim 1 , wherein the separations unit comprises a de-methanizer that receives the OCM product stream and separates the OCM product stream into a de-methanizer overhead comprising C 1 compounds and a de-methanizer bottoms comprising C 2+ compounds.

8 . The system of claim 7 , further comprising a methanation unit in fluid communication with the OCM reactor and the de-methanizer, wherein the methanation unit is configured to receive the de-methanizer overhead comprising C 1 compounds and to generate a stream comprising methane which is received by the OCM reactor.

9 . The system of claim 2 , further comprising a C 3 separations unit that receives the C 3+ stream and separates the C 3+ stream to yield a C 3 stream comprising propylene and a C 4+ stream comprising C 4+ products.

10 . The system of claim 9 , further comprising a C 3 splitter that receives the C 3 stream and separates the C 3 stream to yield a propylene stream and a propane stream.

11 . The system of claim 9 , wherein the C 4 separations unit receives the C 4+ stream.

12 . The system of claim 2 , further comprising a polypropylene unit that receives the propylene from the metathesis product stream and reacts the propylene to yield a polypropylene product stream comprising polypropylene.

13 . The system of claim 12 , wherein the polypropylene unit receives ethylene from the separations unit and reacts the ethylene as a co-monomer with the propylene.

14 . The system of claim 13 , wherein the ratio of ethylene co-monomer to total monomer and co-monomer is from about 0.01:0.99 to about 0.15:0.85

15 . The system of claim 13 , wherein the ratio of ethylene co-monomer to total monomer and co-monomer is from about 0.08:0.92 to about 0.15:0.85.

16 . A method for oxidative coupling of methane (OCM) to generate hydrocarbon compounds containing at least two carbon atoms (C 2+ compounds), comprising:
(a) injecting oxygen (O 2 ), methane (CH 4 ) and ethane (C 2 H 6 ) into an adiabatic OCM reactor, wherein the adiabatic OCM reactor comprises an adiabatic OCM reaction section comprising an OCM catalyst bed for facilitating an OCM reaction and an adiabatic post-bed cracking (PBC) section for facilitating conversion of C 2 H 6 to ethylene (C 2 H 4 ) with the aid of heat liberated by the OCM reaction, and wherein the C 2 H 6 has a concentration of at least 3 mol % at an inlet of the adiabatic OCM reactor and wherein the concentration of C 2 H 6 at the inlet of the adiabatic OCM reactor is maintained within +/−0.2 mol %;
(b) with the aid of the OCM catalyst in the adiabatic OCM reaction section, performing an OCM reaction to convert the CH 4 into C 2+ compounds as part of a product stream;
(c) in the adiabatic PBC section of the adiabatic OCM reactor and with the aid of heat liberated by the OCM reaction, converting C 2 H 6 in the product stream into C 2 H 4 as part of an OCM effluent;
(d) separating the OCM effluent to produce at least an ethane stream and an enriched product stream enriched in C 2 H 4 ;
(e) recycling a portion of the ethane stream to an inlet of the adiabatic OCM reaction section; and
(f) recycling a portion of the ethane stream to the adiabatic PBC section, wherein the method has a carbon efficiency of at least 60%.

17 . The method of claim 16 , wherein the concentration of C 2 H 6 at an inlet of the OCM catalyst bed is at least 3 mol %.

18 . The method of claim 16 , wherein at least a portion of the C 2 H 6 is injected into the OCM reaction section separately from the CH 4 .

19 . The method of claim 16 , further comprising increasing or decreasing an amount of CH 4 injected in (a) to maintain the concentration of C 2 H 6 during the injecting.

20 . The method of claim 16 , wherein the concentration of C 2 H 6 at the inlet of the OCM reactor is from 3 mol % to 6 mol %.

Assignees

• Lummus Technology Inc

Inventors

• Radaelli Guido
• Bridges Robert
• Rafique Humera A
• Duggal Suchia
• Vuddagiri Srinivas
• Cizeron Joel
• Mccormick Jarod
• Patel Bipinkumar
• Lakhapatri Satish

Classifications

• C25B15/083

  Separating products · CPC title

• C25B1/042

  by electrolysis of steam · CPC title

• C25B1/04

  by electrolysis of water · CPC title

• C25B15/08

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title

• C01B2203/0872

  Methods of cooling · CPC title