Ethylene-to-liquids systems and methods
Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.
1. A method, comprising:
(a) directing an olefin feed stream comprising ethylene (C 2 H 4 ), propylene (C 3 H 6 ), methane, and inert species into a treatment unit, and in said treatment unit reducing the concentration in said olefin feed stream of (i) compounds having triple bonds or (ii) compounds having more than one double bond, wherein said reducing is accomplished by a separations process or a reaction process;
(b) directing said olefin feed stream from said treatment unit into a fixed bed ethylene-to-liquids (ETL) reactor, wherein said olefin feed stream comprises less than about 10 weight percent (wt %) C 2 H 4 when directed into said ETL reactor, and wherein said ETL reactor operates substantially adiabatically;
(c) in said ETL reactor, conducting an ETL process to convert said C 2 H 4 or said C 3 H 6 in said olefin feed stream to higher hydrocarbon products, thereby producing a product stream comprising said higher hydrocarbon products, wherein said higher hydrocarbon products comprise a paraffin compound, an isoparaffin compound, and a naphthene compound; and
(d) directing said product stream from said ETL reactor and recovering from said product stream a liquid stream comprising said higher hydrocarbon products.
2. The method of claim 1 , wherein said olefin feed stream is directed into said treatment unit from a refinery.
3. The method of claim 1 , wherein said higher hydrocarbon products comprise different compounds selected from compounds having carbon numbers 4 through 30.
4. The method of claim 3 , wherein said higher hydrocarbon products comprise different compounds selected from compounds having carbon numbers 4 through 19.
5. The method of claim 1 , wherein said higher hydrocarbon products comprise a paraffin compound, an isoparaffin compound, and a naphthene compound.
6. The method of claim 1 , wherein said higher hydrocarbon products comprise an olefin compound or an aromatic compound.
7. The method of claim 1 , wherein said ETL reactor operates substantially adiabatically.
8. The method of claim 1 , wherein said olefin feed stream, when directed into said ETL reactor in (b), comprises less than about 100 parts per million (ppm) of acetylene.
9. The method of claim 1 , wherein said olefin feed stream, when directed into said ETL reactor in (b), comprises less than or equal to about 5 mol % carbon monoxide (CO).
10. The method of claim 1 , wherein said treatment unit comprises an acetylene hydrogenation catalyst with a lifetime of at least about 6 months.
11. The method of claim 1 , wherein said treatment unit comprises a guard bed.
12. The method of claim 1 , wherein said higher hydrocarbon products are generated at a single pass conversion of at least about 40%.
13. The method of claim 1 , wherein said ETL reactor is operated at a temperature greater than or equal to about 200° C.
14. The method of claim 1 , wherein said ETL reactor is operated at a pressure greater than or equal to about 200 pounds per square inch.
15. The method of claim 1 , wherein said product stream comprises less than 50 weight percent (wt %) water.
16. The method of claim 1 , wherein said olefin feed stream, when directed into said ETL reactor, comprises less than about 100 parts per million (ppm) of acetylene.
17. The method of claim 1 , wherein a process temperature of said ETL reactor is between about 200° C. and about 375° C.