POWER PLANT WITH CO2 CAPTURE AND COMPRESSION

• US 20110056200A1
• Filed: 07/09/2010
• Published: 03/10/2011
• Est. Priority Date: 01/11/2008
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Paelinck, Philippe Jean-Michel, Pfeffer, Allen Michael, Steinbach, Christian, Hoffmann, Jurgen, SOOTHILL, Charles
• Granted Patent: US 8,346,394 B2
• Time in Patent Office: Days
• US Class Current: 60/645
• CPC Class Codes: F01K 13/02 Controlling, e.g. stopping or starting
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
• CPC Class Codes: Y02E 20/18 Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS]
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation

Abstract

Power plant characteristics are operated in a flexible manner by controlling the power consumption of a CO₂ capture and compression system. The impact of CO₂ capture and compression on the capacity of a power plant can be minimized to maximize the electric power the plant can deliver to the power grid and the impact of CO₂ capture and compression on the average plant efficiency can be reduced, by an operating method and a power plant, in which the power consumption of the CO₂ capture system is used to control the net output of the plant.

Claims

1. A method for operating a power plant, the method comprising:

operating the plant via a control system and CO₂ capture system; and

using a power consumption of the CO₂ capture system as a control parameter for controlling net power output of the plant.

2. A method according to claim 1, comprising:

controlling the CO₂ capture system by a closed loop control system, which is integrated into the control system or coordinated by the control system or has a direct data link to the plant control system.

3. A method according to claim 1, comprising:

operating the CO₂ capture system at reduced capacity or shutting down the CO₂ capture system in order to supply additional power to the grid; and

using this additional power to increase rated plant capacity.

4. A method according to claim 1, comprising:

operating the power plant close to or at design point when the CO₂ capture system is in operation; and

using the power consumption of the CO₂ capture system as capacity reserve.

5. A method according to claim 1, comprising:

controlling the plant to maintain thermal load of the plant constant; and

control the power consumption of the CO₂ capture system to vary the net power output to a grid.

6. A method according to claim 1, comprising:

varying a CO₂ capture rate to control the power consumption of the CO₂ capture system.

7. A method according to claim 1, wherein the CO₂ capture system comprises a CO₂ compressor unit, the method comprising:

shutting down the CO₂ compression unit or operating the CO₂ compression unit at reduced capacity.

8. A method according to claim 7, comprising:

releasing a part of or all captured CO₂ via a bypass of the CO₂ compression unit.

9. A method according to claim 1, wherein the CO₂ capture system comprises a regeneration unit, the method comprising:

shutting down the regeneration unit or operating the regeneration unit at reduced capacity.

10. A method according to claim 1, wherein the CO₂ capture system comprises an absorption or adsorption unit, the method comprising:

shutting down the absorption or adsorption unit or operating the absorption or adsorption unit at reduced capacity.

11. A method according to claim 10, comprising bypassing a part of or all flue gas around the CO₂ capture system.

12. A method according to claim 9, wherein regeneration takes place at reduced capacity at times of high power demand, and wherein a stored absorbent or adsorbent is used for CO₂ capture during this time.

13. A method according to claim 12, comprising:

reducing a steam consumption of the regeneration unit comprised in the capture system due to the shut down or operation at reduced capacity; and

feeding surplus steam to at least one steam turbine of the plant.

14. A method according to claim 12, wherein regeneration of the absorbent or adsorbent takes place at times of low power demand.

15. A power plant, comprising:

a CO₂ capture system; and

a control system for receiving power consumption of the CO₂ capture system as a control parameter for controlling net power output of the plant.

16. A power plant according to claim 15, comprising:

at least one steam turbine for converting a maximum steam flow into energy, which can be produced by the plant with the CO₂ capture system switched off.

17. A power plant according to claim 15, comprising:

at least one generator and electrical systems for converting a maximum power, which is produced with the CO₂ capture system off, into electrical power and to transmit this electric power to the grid.

18. A power plant according to claim 15, wherein the CO₂ capture system includes at least one of a CO₂ compressor unit and an absorption unit having,

a bypass.

19. A power plant according to claim 15, wherein the absorption unit comprised in the capture system is designed to withstand flue gases even when not in operation.

20. A power plant according to claim 15, wherein the CO₂ capture system includes a regeneration unit and a storage tank for an absorbent or an adsorbent, which allows capture of CO₂ even when the regeneration unit in the capture system is operating at reduced capacity or is off.

21. A power plant according to claim 20, wherein the regeneration unit in the capture system has a capacity, which is larger than is required for steady state operation of the power plant in order to have additional capacity to regenerate stored absorbent or adsorbent.

22. A power plant according to claim 15, comprising:

chilled ammonia for the CO₂ capture system; and

a storage tank for cooling medium, which is used for chilling during periods of high power demand, wherein the chilling equipment is oversized to have capacity to cool down stored cooling medium during periods of low power demand.