Natural gas processing and systems
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.
1. 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) directing a feed stream comprising methane from a hydrocarbon process into an oxidative coupling of methane (OCM) reactor at an inlet temperature between about 400° C. and about 600° C., wherein the OCM reactor is configured to perform one or more OCM reactions to generate C 2+ compounds from said methane, wherein said OCM reactor comprises a nanostructured catalyst that catalyzes said one or more OCM reactions, and wherein said hydrocarbon process is a non-OCM process;
(b) performing said one or more OCM reactions in the OCM reactor using said methane to produce a product stream comprising one or more C 2+ compounds;
(c) separating the product stream into at least a first stream and a second stream, wherein the first stream has a lower C 2+ concentration than said second stream, and wherein said second stream has a higher C 2+ concentration than said product stream; and
(d) directing said second stream into said hydrocarbon process.
2. The method of claim 1 , wherein the hydrocarbon process is an oil refinery, a natural gas liquids process, or a cracker.
3. The method of claim 1 , wherein at least a portion of said first stream is directed into said OCM reactor.
4. The method of claim 1 , a concentration of C 2+ compounds in said second stream is less than about 90%.
5. The method of claim 4 , wherein said first stream has a concentration of C 2+ compounds that is less than about 50%.
6. The method of claim 1 , wherein said product stream is separated in at most three separation units.
7. The method of claim 6 , wherein said product stream is separated in at most two separations units.
8. The method of claim 1 , wherein said separating is with the aid of pressure swing adsorption.
9. The method of claim 1 , wherein said separating is with the aid of cryogenic separation.
10. The method of claim 1 , wherein said first stream and said second stream are directed into said hydrocarbon process.
11. The method of claim 1 , wherein a concentration of C 2+ compounds in said second stream is within about 20% of a concentration of the C 2+ compounds in a portion of said hydrocarbon process into which the second stream is directed.
12. The method of claim 1 , wherein said product stream further comprises non-C 2+ impurities.
13. The system of claim 12 , wherein said non-C 2+ impurities comprise one or more of nitrogen (N 2 ), water (H 2 O), argon (Ar), carbon monoxide (CO), carbon dioxide (CO 2 ) and methane (CH 4 ).
14. The method of claim 12 , wherein said second stream has a lower concentration of said non-C 2+ impurities than said first stream.
15. The method of claim 1 , wherein said one or more C 2+ compounds are hydrocarbons having between two and five carbon atoms.
16. The method of claim 1 , wherein the C 2+ compounds comprise ethylene.
17. The method of claim 1 , wherein a mass flow rate of the second stream is less than about 30% of a mass flow rate of a portion of said hydrocarbon process into which the second stream is directed.
18. The method of claim 1 , wherein said separating is with the aid of a lean oil extraction system.
19. The method of claim 1 , wherein said separating comprises:
(i) introducing said product stream comprising one or more C 2+ compounds and a non-C 2+ impurity into a vessel at a first pressure, wherein the vessel comprises an adsorbent medium, wherein upon introducing said product stream into said vessel, said product stream is brought in contact with said adsorbent medium;
(ii) changing the pressure in the vessel to a second pressure to release (i) at least a subset of said one or more C 2+ compounds or (ii) said non-C 2+ impurities from said adsorbent medium, thereby separating said at least the subset of said one or more C 2+ compounds from said non-C 2+ impurities; and
(iii) recovering said at least the subset of said one or more C 2+ compounds in said second stream.
20. The method of claim 1 , wherein said separating is with the aid of one or more of a de-ethanizing unit, a de-propanizing unit and a de-butanizing unit.
21. The method of claim 1 , wherein the OCM reactor has a reactor inlet temperature of between about 400° C. and 600° C., and a pressure of less than 150psig, wherein the one or more OCM reactions has a methane conversion of at least 10% in a single process pass and a C 2 + selectivity of at least 50%.
22. The method of claim 1 , wherein the nanostructured catalyst comprises a nanowire.
23. The method of claim 1 , wherein said C 2+ compounds comprise ethylene, and further comprising, following (b) and prior to (c), transferring the product stream to an oligomerization system to produce one or more higher hydrocarbon compounds from the C 2+ compounds in the product stream.
24. The method of claim 1 , wherein the nanostructured catalyst comprises a nanoparticle.