Production of low pressure liquid carbon dioxide from a power production system and method

Patent metadata

Field	Value
Publication number	US-10047673-B2
Application number	US-201514848909-A
Country	US
Kind code	B2
Filing date	Sep 9, 2015
Priority date	Sep 9, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

The present disclosure relates to systems and methods that provide a low pressure liquid CO2 stream. In particular, the present disclosure provides systems and methods wherein a high pressure CO2 stream, such as a recycle CO2 stream from a power production process using predominately CO2 as a working fluid, can be divided such that a portion thereof can be expanded and used as a cooling stream in a heat exchanger to cool the remaining portion of the high pressure CO2 stream, which can then be expanded to form a low pressure CO2 stream, which may be in a mixed form with CO2 vapor. The systems and methods can be utilized to provide net CO2 from combustion in a liquid form that is easily transportable.

First claim

The invention claimed is:

1. A method for production of a low pressure liquid carbon dioxide (CO2) stream, the method comprising:
combusting a carbonaceous or hydrocarbon fuel with oxygen in a combustor in the presence of a recycle CO2 stream at a pressure of 100 bar (10 MPa) to 400 bar (40 MPa) and a temperature of 400° C. to 1600° C. to form a combustor exit stream comprising CO2;
expanding the combustor exit stream in a turbine to generate power and form a turbine exit stream comprising CO2 at a pressure of 50 bar (5 MPa) or less;
cooling the turbine exit stream in a first heat exchanger to form a cooled turbine exit stream;
pumping CO2 from the cooled turbine exit stream to a pressure of 100 bar (10 MPa) to 500 bar (50 MPa) to form a high pressure CO2 stream;
dividing the high pressure CO2 stream into a bulk portion and a cooling portion;
expanding the cooling portion of the high pressure CO2 stream to reduce the temperature thereof to −20° C. or less;
cooling the bulk portion of the high pressure CO2 stream to a temperature of 5° C. or less by passing the bulk portion of the high pressure CO2 stream through a second heat exchanger against the expanded cooling portion of the high pressure CO2 stream; and
expanding the cooled, bulk portion of the high pressure CO2 stream to a pressure that is about 30 bar (3 MPa) or less but is greater than the triple point pressure of CO2 so as to form the low pressure liquid CO2 stream.

2. The method according to claim 1 , wherein the combustor exit stream is at a pressure of 200 bar (20 MPa) to 400 bar (40 MPa).

3. The method according to claim 1 , wherein the combustor exit stream is at a temperature of 800° C. to 1,600° C.

4. The method according to claim 1 , wherein the turbine exit stream comprising CO2 is at a pressure of 20 bar (2 MPa) to 10 bar (4 MPa).

5. The method according to claim 1 , wherein the turbine exit stream is cooled in the heat exchanger to a temperature of 80° C. or less.

6. The method according to claim 5 , further comprising passing the cooled turbine exit stream comprising CO 2 through one or more separators to remove at least water therefrom.

7. The method according to claim 1 , further comprising heating one or both of the oxygen and the recycle CO 2 stream in the heat exchanger against the turbine exit stream.

8. The method according to claim 1 , wherein the high pressure CO2 stream is at a pressure of 200 bar (20 MPa) to 400 bar (40 MPa).

9. The method according to claim 1 , wherein the bulk portion of the high pressure CO2 stream is cooled to a temperature of −55° C. to 0° C.

10. The method according to claim 1 , further comprising, after said cooling of the bulk portion of the high pressure CO 2 stream and prior to said expanding of the bulk portion of the high pressure CO 2 stream, passing the bulk portion of the high pressure CO 2 stream through a re-boiler.

11. The method according to claim 10 , wherein the re-boiler is in a stripping column.

12. The method according to claim 1 , further comprising passing the low pressure liquid CO 2 stream through a separator effective to separate a vapor stream therefrom.

13. The method according to claim 12 , wherein the vapor stream comprises up to 8% by mass of the low pressure liquid CO2 stream passed through the separator.

14. The method according to claim 12 , wherein the vapor stream comprises 1% to 75% by mass CO2 and 25% to 99% by mass of one or more of N2, 02, and Argon.

15. The method according to claim 12 , further comprising passing the remaining low pressure liquid CO2 stream into a stripping column after passing through the separator.

16. The method according to claim 15 , wherein the low pressure liquid CO2 stream exiting the stripping column has an oxygen content of no more than 25 ppm.

17. The method according to claim 15 , comprising pumping the low pressure liquid CO2 stream to a pressure of 100 bar (10 MPa) to 250 bar (25 MPa) to form a pumped liquid CO2 stream.

18. The method according to claim 17 , comprising delivering the pumped liquid CO 2 stream to a CO 2 pipeline.

19. The method according to claim 1 , further comprising mixing an overhead vapor from the stripping column with the cooling portion of the high pressure CO2 stream exiting the second heat exchanger to form a mixture.

20. The method according to claim 19 , further comprising adding the mixture to the cooled turbine exit stream.

Assignees

• 8 Rivers Capital Llc

Inventors

• Allam Rodney John
• Forrest Brock Alan
• Fetvedt Jeremy Eron

Classifications

• B01D53/002

  by condensation · CPC title

• B01D53/265

  by refrigeration (condensation) · CPC title

• C01B32/50 Primary

  Carbon dioxide · CPC title

• F02C6/04 Primary

  Gas-turbine plants providing heated or pressurised working fluid for other apparatus, e.g. without mechanical power output (F02C6/18 takes precedence {; for a fluidised-bed combustor F02C3/205}) · CPC title

• F23J15/02

  of purifiers, e.g. for removing noxious material (traps for solid residues F23J3/04) · CPC title