Hydrocarbon distillation

• US 10,539,364 B2
• Filed: 03/13/2017
• Issued: 01/21/2020
• Est. Priority Date: 03/13/2017
• Status: Active Grant

• Current Assignee: Baker Hughes, a GE Company, LLC (Baker Hughes Company)
• Original Assignee: General Electric Company
• Inventors: Repasky, John Michael
• Primary Examiner(s): Jones, Melvin
• Application Number:
  US15/457,548
• Publication Number:
  US 20180259250A1
• Time in Patent Office: 1,044 Days
• Field of Search: 62620-628, 62611-613
• CPC Class Codes: F25J 1/0022 Hydrocarbons, e.g. natural gas
• CPC Class Codes: F25J 1/0052 by vaporising a liquid refrigerant stream
• CPC Class Codes: F25J 1/0212 as a single flow MCR cycle
• CPC Class Codes: F25J 1/023 for the combustion as fuels, i.e. integration with the fuel gas system
• CPC Class Codes: F25J 1/0235 Heat exchange integration
• CPC Class Codes: F25J 1/0238 Purification or treatment step is integrated within one refrigeration cycle only, i.e. the same or single refrigeration cycle provides feed gas cooling (if present) and overhead gas cooling
• CPC Class Codes: F25J 1/0242 Waste heat recovery, e.g. from heat of compression
• CPC Class Codes: F25J 1/0284 Electrical motor as the prime mechanical driver
• CPC Class Codes: F25J 1/0296 Removal of the heat of compression, e.g. within an inter- or afterstage-cooler against an ambient heat sink
• CPC Class Codes: F25J 2200/02 in a single pressure main column system
• CPC Class Codes: F25J 2200/40 Features relating to the provision of boil-up in the bottom of a column
• CPC Class Codes: F25J 2220/64 Separating heavy hydrocarbons, e.g. NGL, LPG, C4+ hydrocarbons or heavy condensates in general
• CPC Class Codes: F25J 2230/04 Compressor cooling arrangement, e.g. inter- or after-stage cooling or condensate removal
• CPC Class Codes: F25J 2230/30 Compression of the feed stream
• 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 3/0247 separation of CnHm with 4 carbon atoms or more

Abstract

Systems and methods are provided for increasing the efficiency of liquefied natural gas production and heavy hydrocarbon distillation. In one embodiment, air within an LNG production facility can be utilized as a heat source to provide heat to HHC liquid for distillation in a HHC distillation system. The mechanism of heat transfer from the air can be natural convection. In another embodiment, heat provided by natural gas, or compressed natural gas, can be used for HHC distillation. In other embodiments, various other liquids can be used to transfer heat to HHC liquid for distillation.

Claims

1. A system for producing liquefied natural gas (LNG) and separating heavy hydrocarbon components, comprising:

a refrigerant supply system including a first valve configured to supply a refrigerant fluid to accept heat from a natural gas feedstock;

a compression system, including at least one compressor configured to receive and compress the refrigerant fluid;

a condenser coupled to the compression system, the condenser configured to output condensed refrigerant fluid via a second valve; and

a distillation column coupled to the condenser and configured to receive the condensed refrigerant fluid via the second valve, the distillation column having a first heat exchanger connected to a second heat exchanger via at least one downcomer and at least one riser, wherein the at least one downcomer and the at least one riser include a valve to control heat transferred to a liquid containing heavy hydrocarbon components, the first heat exchanger and the second heat exchanger configured with heat pipes to aid transferring heat to the liquid containing heavy hydrocarbon components such that the liquid boils to form vapor thereby allowing the heavy hydrocarbon components to be separated and collected, the heat being transferred from a heated fluid comprising at least a portion of the natural gas feedstock, wherein the heat is transferred from the heated fluid by natural convection or forced convection and the heat being transferred from the heated fluid is delivered to the first heat exchanger from the second heat exchanger.

2. The system of claim 1, wherein the first heat exchanger is a reboiler.

3. A method for separating heavy hydrocarbon components, comprising:

delivering a fluid from a refrigerant supply system to a condenser coupled to the refrigerant supply system and condensing the fluid;

delivering the condensed fluid to a first heat exchanger configured within a distillation column that contains a liquid containing heavy hydrocarbon components;

providing the liquid to the first heat exchanger via a downcomer coupling the heat exchanger to the distillation column, the downcomer including a control valve;

transferring heat from the fluid to the liquid such that the liquid boils to form a vapor containing heavy hydrocarbon components, wherein heat is transferred to the liquid at a rate determined by a setting of the downcomer control valve and/or a riser control valve included in a riser configured to provide the vapor to the distillation column from the heat exchanger, the riser coupling the heat exchanger and the distillation column;

extracting heat from the vapor such that desired heavy hydrocarbon components condense to form a distilled heavy hydrocarbon liquid; and

collecting the condensed distilled heavy hydrocarbon liquid.

4. The method of claim 3, wherein the fluid is ambient air.

5. The method of claim 4, wherein the heat is transferred from the air via natural convection.

6. The method of claim 4, wherein the heat is transferred from the air via forced convection.

7. The method of claim 3, wherein the fluid is natural gas (NG) feedstock that is used to produce LNG.

8. The method of claim 3, wherein the heat is transferred from air in the distillation column to the fluid via a second heat exchanger that is thermally coupled to the first heat exchanger.

9. The method of claim 8, wherein the heat is transferred from the air via natural convection.

10. The method of claim 8, wherein the heat is transferred from the air via forced convection.

11. The method of claim 3, wherein the heat is transferred from a NG feedstock to the fluid via a second heat exchanger that is thermally coupled to the first heat exchanger.

12. The method of claim 3, wherein the heat is transferred from a refrigerant to the fluid, the refrigerant having received heat from an NG feedstock.

13. The method of claim 3, wherein a refrigerant is heated during compression and heat is transferred from the refrigerant to the fluid after compression.