Method and system for carbon dioxide energy storage in a power generation system

1. A carbon dioxide (CO2) energy storage system comprising:

a storage tank configured to store a CO2 slurry including dry ice and liquid CO2, wherein said storage tank stores the slurry at the CO2 triple point temperature and pressure;

a first pump coupled in flow communication with said storage tank, wherein said first pump is configured to receive the CO2 slurry from said storage tank and to increase a pressure of the CO2 slurry to a pressure above the CO2 triple point pressure;

a contactor coupled in flow communication with said first pump, wherein said contactor is configured to receive the CO2 slurry from said pump and also to receive a first flow of gaseous CO2 at a pressure above the CO2 triple point pressure;

a decanter coupled in flow communication with said storage tank, wherein said decanter is configured to receive a flow of the CO2 slurry from said storage tank and to remove a flow of high percentage dry ice slurry from the flow of CO2 slurry; and

a second pump coupled in flow communication between said decanter and said contactor, wherein said second pump is configured to channel the flow of high percentage dry ice slurry from the CO2 slurry to said contactor at a pressure above the CO2 triple point pressure.

2. The CO2 energy storage system of claim 1 , further comprising a mixer coupled in flow communication with said first pump, said second pump, and said contactor, wherein said mixer is configured to mix the CO2 slurry from said first pump and the flow of high percentage dry ice slurry from said second pump.

3. The CO2 energy storage system of claim 1 , further comprising a first contactor outlet line coupled in flow communication between said contactor and said storage tank, wherein said first contactor outlet line is configured to channel a flow of liquid CO2 from said contactor to said storage tank.

4. The CO2 energy storage system of claim 3 , further comprising a second contactor outlet line and a mixer, wherein said second contactor outlet line is configured to channel a second flow of gaseous CO2 from said contactor to said mixer and said mixer is configured to mix the second flow of gaseous CO2 from said contactor with the first flow of gaseous CO2.

5. The CO2 energy storage system of claim 1 , further comprising a recirculation loop coupled in flow communication with said storage tank, wherein said recirculation loop is configured to remove gaseous CO2 from said storage tank and condense the gaseous CO2 into a liquid CO2 and to channel the liquid CO2 back into said storage tank.

6. A power generation system comprising:

a power generation cycle comprising a CO2 turbine; and

a CO2 storage system coupled in flow communication with said power generation cycle, said CO2 storage system comprising:

a storage tank configured to store a CO2 slurry including dry ice and liquid CO2, wherein said storage tank stores the slurry at the CO2 triple point temperature and pressure;

a first pump coupled in flow communication with said storage tank, wherein said first pump is configured to receive the CO2 slurry from said storage tank and to increase a pressure of the CO2 slurry to a pressure above the CO2 triple point pressure;

a contactor coupled in flow communication with said first pump, wherein said contactor is configured to receive the CO2 slurry from said pump and also to receive a first flow of gaseous CO2 from said CO2 turbine at a pressure above the CO2 triple point pressure;

a decanter coupled in flow communication with said storage tank, wherein said decanter is configured to receive a flow of the CO2 slurry from said storage tank and to remove a flow of high percentage dry ice slurry from the flow of CO2 slurry; and

a second pump coupled in flow communication between said decanter and said contactor, wherein said second pump is configured to channel the flow of high percentage dry ice slurry from the CO2 slurry to said contactor at a pressure above the CO2 triple point pressure.

7. The power generation system of claim 6 , further comprising a mixer coupled in flow communication with said first pump, said second pump, and said contactor, wherein said mixer is configured to mix the CO2 slurry from said first pump and the flow of high percentage dry ice slurry from said second pump.

8. The power generation system of claim 6 , wherein said power generation cycle comprises:

a heat recovery vapor generator coupled in flow communication between said storage tank and said turbine, wherein said heat recovery vapor generator is configured to receive a flow of liquid CO2 from said storage tank and to increase a temperature of said flow of liquid CO2;

a feed pump coupled in flow communication between said heat recovery vapor generator and said storage tank, wherein said feed pump is configured to increase a pressure of the flow of liquid CO2; and

a recuperator coupled in flow communication between said turbine and said contactor, wherein said recuperator is configured to remove heat from the first flow gaseous CO2.

9. The power generation system of claim 6 , further comprising:

a first contactor outlet line coupled in flow communication between said contactor and said storage tank, wherein said first contactor outlet line is configured to channel a flow of liquid CO2 from said contactor to said storage tank; and

a control mechanism coupled in flow communication with said first contactor outlet line, wherein said control mechanism is configured to maintain a pressure within said contactor above the CO2 triple point pressure.

10. The power generation system of claim 6 , further comprising a recirculation loop coupled in flow communication with said storage tank, wherein said recirculation loop is configured to remove gaseous CO2 from said storage tank and condense the gaseous CO2 into a liquid CO2 and to channel the liquid CO2 back into said storage tank.

11. A method of operating a power generation system including a power generation cycle and a CO2 storage system, wherein said method comprises:

storing a slurry of dry ice and liquid CO2 in a storage tank at the triple point temperature and pressure of CO2;

pumping the slurry through a first pump to increase the pressure of the slurry above the CO2 triple point pressure;

channeling the slurry to a contactor;

channeling a first flow of gaseous CO2 to the contactor at a pressure above the CO2 triple point pressure;

contacting the flow of slurry with the first flow of high pressure gaseous CO2 within the contactor to condense the gaseous CO2 into liquid CO2;

channeling a flow of CO2 slurry from the storage tank to a decanter and removing a flow of high percentage dry ice slurry from the flow of CO2 slurry using the decanter; and

channeling the flow of high percentage dry ice slurry from the decanter to the contactor using a second pump, wherein the second pump increases the pressure of the flow of dry ice to above the CO2 triple point pressure.

12. The method of claim 11 , further comprising mixing the flow of high percentage dry ice slurry from the second pump with the flow of slurry from the first pump in a mixer and channeling the mixed flows of slurry and dry ice to the contactor.

13. The method of claim 11 , further comprising channeling a flow of liquid CO2 from the contactor to the storage tank through a first contactor outlet line.

14. The method of claim 11 , further comprising:

removing a second flow of gaseous CO2 from the storage tank;

condensing the second flow of gaseous CO2 into a flow of liquid CO2; and

channeling the flow of liquid CO2 into the storage tank.

15. The method of claim 11 , further comprising:

removing a second flow of gaseous CO2 from the contactor;

mixing the second flow of gaseous CO2 with the first flow of gaseous CO2; and

channeling the mixed first and second flows of gaseous CO2 to the contactor.