Conditioning an ethane-rich stream for storage and transportation

1. A process comprising:

receiving an ethane-rich stream comprising at least about 70 molar percent ethane;

conditioning the ethane-rich stream to a temperature from about −160° F. to about 0° F.;

removing substantially all of a vapor fraction from the ethane-rich stream, wherein the vapor fraction is used to condition the ethane-rich stream;

combining the vapor fraction with the ethane-rich stream after the vapor fraction has conditioned the ethane-rich stream; and

transporting the conditioned ethane-rich stream.

2. The process of claim 1 , wherein the conditioned ethane-rich stream is transported in a liquefied natural gas (LNG) tanker ship or rail car.

3. The process of claim 2 , wherein the ethane-rich stream comprises at least about 80 molar percent ethane, and wherein the conditioned ethane-rich stream has a pressure from about 14.7 pounds per square inch absolute (psia) to about 100 psia.

4. The process of claim 2 , wherein the ethane-rich stream comprises at least about 90 molar percent ethane, wherein the temperature of the conditioned ethane-rich stream is from about −120° F. to about −40° F., and wherein the conditioned ethane-rich stream has a pressure from about 20 pounds per square inch absolute (psia) to about 80 psia.

5. The process of claim 2 , wherein the ethane-rich stream comprises at least about 95 molar percent ethane, wherein the temperature of the conditioned ethane-rich stream is from about −100° F. to about −60° F., and wherein the conditioned ethane-rich stream has a pressure from about 30 pounds per square inch absolute (psia) to about 70 psia.

6. The process of claim 2 , wherein the ethane-rich stream comprises at least about 97 molar percent ethane, wherein the temperature of the conditioned ethane-rich stream is from about −90° F. to about −70° F., and wherein the conditioned ethane-rich stream has a pressure from about 40 pounds per square inch absolute (psia) to about 60 psia.

7. The process of claim 2 , wherein the ethane-rich stream comprises at least about 98 molar percent ethane, wherein the temperature of the conditioned ethane-rich stream is about −80° F., and wherein the conditioned ethane-rich stream has a pressure about 50 pounds per square inch absolute (psia).

8. A process comprising:

receiving an ethane-rich stream;

adjusting a temperature, a pressure, or both of the ethane-rich stream such that the ethane-rich stream has a temperature from about −160° F. to about 0° F. and a pressure from about 14.7 pounds per square inch absolute (psia) to about 100 psia;

removing substantially all of a vapor fraction from the ethane-rich stream, wherein the vapor fraction is used to adjust the temperature, the pressure, or both of the ethane-rich stream; and

combining the vapor fraction with the ethane-rich stream after adjusting the temperature, pressure, or both of the ethane-rich stream.

9. The process of claim 8 further comprising:

removing substantially all of any liquid water; and

subsequently removing substantially all of any water vapor.

10. The process of claim 8 , wherein adjusting a temperature, a pressure, or both comprises:

passing the ethane-rich stream through a plurality of heat exchangers; and

throttling the ethane-rich stream.

11. The process of claim 10 , wherein at least one of the heat exchangers is serviced by an external refrigeration process.

12. The process of claim 10 further comprising:

receiving an ethane-rich vapor return stream from a storage tank, a transportation vessel, or both; and

combining the ethane-rich vapor return stream with the vapor fraction, thereby producing an ethane-rich vapor stream,

wherein the ethane-rich vapor stream is used to adjust the temperature, the pressure, or both of the ethane-rich stream.

13. The process of claim 12 , wherein the ethane-rich stream is passed through a first heat exchanger, then a second heat exchanger, and then a third heat exchanger, wherein the second heat exchanger is serviced by an external refrigeration process, and wherein the ethane-rich vapor stream passes through the third heat exchanger, and then the first heat exchanger.

14. The process of claim 13 , wherein the ethane-rich vapor stream is compressed, cooled, and combined with the ethane-rich stream after passing through the first heat exchanger.

15. The process of claim 14 further comprising:

receiving a natural gas stream; and

separating the ethane-rich stream from the natural gas stream.

16. A process comprising:

receiving an ethane-rich stream comprising at least about 90 molar percent ethane;

conditioning the ethane-rich stream to a temperature from about −120° F. to about −40° F. and a pressure from about 20 pounds per square inch absolute (psia) to about 80 psia;

removing substantially all of a vapor fraction from the ethane-rich stream, wherein the vapor fraction is used to condition the ethane-rich stream;

combining the vapor fraction with the ethane-rich stream after the vapor fraction has conditioned the ethane-rich stream; and

transporting the conditioned ethane-rich stream to a ship, a rail car, a storage tank, or combinations thereof.

17. The process of claim 16 , wherein the ethane-rich stream comprises at least about 95 molar percent ethane, wherein the temperature is from about −100° F. to about −60° F., and wherein the pressure is from about 30 psia to about 70 psia.

18. The process of claim 16 , wherein the ethane-rich stream comprises at least about 98 molar percent ethane, wherein the temperature is about −80° F., and wherein the pressure is about 50 psia.

19. The process of claim 18 , wherein the ship is a liquefied natural gas (LNG) tanker destined for Europe or the U.S. Gulf Coast.

20. The process of claim 1 , wherein conditioning the ethane-rich stream comprises:

passing the ethane-rich stream through one or more heat exchangers; and

passing the vapor fraction through a last of the one or more heat exchangers prior to removing substantially all of the vapor fraction.

21. The process of claim 20 , wherein conditioning the ethane-rich stream occurs before removing substantially all of any vapor fraction from the ethane-rich stream.

22. The process of claim 1 , wherein the conditioned ethane-rich stream comprises no more than about 5 molar percent vapor.

23. The process of claim 8 , wherein adjusting the temperature, the pressure, or both of the ethane-rich stream comprises:

passing the ethane-rich stream through one or more heat exchangers; and

passing the vapor fraction through a last of the one or more heat exchangers prior to removing substantially all of the vapor fraction.

24. The process of claim 23 , wherein adjusting the temperature, the pressure, or both of the ethane-rich stream occurs before removing substantially all of any vapor fraction from the ethane-rich stream.

25. The process of claim 8 , wherein the adjusted ethane-rich stream comprises no more than 5 molar percent vapor.

26. The process of claim 8 , wherein the ethane-rich stream comprises at least about 70 molar percent ethane.

27. The process of claim 16 , wherein conditioning the ethane-rich stream comprises:

passing the ethane-rich stream through one or more heat exchangers; and

passing the vapor fraction through a last of the one or more heat exchangers prior to removing substantially all of the vapor fraction.

28. The process of claim 27 , wherein conditioning the ethane-rich stream occurs before removing substantially all of any vapor fraction from the ethane-rich stream.

29. The process of claim 16 , wherein the conditioned ethane-rich stream comprises no more than 5 molar percent vapor.