Conditioning an Ethane-Rich Stream for Storage and Transportation

• US 20110132033A1
• Filed: 12/07/2009
• Published: 06/09/2011
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: Alkane LLC
• Original Assignee: Alkane LLC
• Inventors: PRIM, Eric
• Granted Patent: US 8,707,730 B2
• Time in Patent Office: Days
• US Class Current: 62/618
• CPC Class Codes: C10L 3/101 Removal of contaminants
• CPC Class Codes: C10L 3/106 of water
• CPC Class Codes: F25J 2205/02 using simple phase separation in a vessel or drum
• CPC Class Codes: F25J 2215/04 Recovery of liquid products
• CPC Class Codes: F25J 2215/62 Ethane or ethylene
• CPC Class Codes: F25J 2260/20 Integration in an installation for liquefying or solidifying a fluid stream
• CPC Class Codes: F25J 2270/12 External refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2290/34 Details about subcooling of liquids
• CPC Class Codes: F25J 2290/62 Details of storing a fluid in a tank
• CPC Class Codes: F25J 3/0209 Natural gas or substitute natural gas
• CPC Class Codes: F25J 3/0233 separation of CnHm with 1 carbon atom or more
• CPC Class Codes: F25J 3/0238 separation of CnHm with 2 carbon atoms or more
• CPC Class Codes: F25J 3/0242 separation of CnHm with 3 carbon atoms or more

Abstract

A process comprising receiving an ethane-rich stream comprising at least about 70 molar percent ethane, conditioning the ethane-rich stream to a temperature such that the ethane-rich stream has a vapor pressure similar to the vapor pressure of conventional liquefied natural gas (LNG), and transporting the conditioned ethane-rich stream. Included is a plurality of processing equipment configured to implement 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, and removing substantially all of any vapor fraction from the ethane-rich stream.

Claims

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 such that the ethane-rich stream has a vapor pressure similar to the vapor pressure of conventional liquefied natural gas (LNG); 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, wherein the conditioned ethane-rich stream has a temperature from about −

160°

F. to about 0°

F., 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 conditioned ethane-rich stream has a temperature 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 conditioned ethane-rich stream has a temperature 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 conditioned ethane-rich stream has a temperature 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 conditioned ethane-rich stream has a temperature about −

80°

F., and wherein the conditioned ethane-rich stream has a pressure about 50 pounds per square inch absolute (psia).

8. A plurality of processing equipment configured to implement 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; and

removing substantially all of any vapor fraction from the ethane-rich stream.

9. The processing equipment of claim 8 further comprising:

removing substantially all of any liquid water; and

subsequently removing substantially all of any water vapor.

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

12. The processing equipment of claim 10, wherein the vapor fraction is used to adjust the temperature, the pressure, or both of the ethane-rich stream.

13. The processing equipment of claim 10, wherein the method further comprises:

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.

14. The processing equipment of claim 13, 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.

15. The processing equipment 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.

16. The processing equipment of claim 15, wherein the process further comprises:

receiving a natural gas stream; and

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

17. A plurality of processing equipment configured to implement 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; and

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

18. The processing equipment of claim 17, 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.

19. The processing equipment of claim 17, 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.

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