High temperature thermochemical energy storage system
A thermochemical energy storage system and method of storing thermal energy are described. The energy storing system described herein comprises a reactor comprising: a) a reactor with a CO 2 sorbent including MgO; and b) a supercritical CO 2 source with supercritical CO 2 and H 2 O, wherein the supercritical CO 2 source is in fluid communication with the reactor and the CO 2 sorbent including MgO to allow flow of the supercritical CO 2 and H 2 O between the supercritical CO 2 source and the reactor, thereby allowing contact of CO 2 with the CO 2 sorbent comprising MgO.
1. A system for storing energy comprising:
a) a reactor comprising a CO 2 sorbent comprising MgO; and
b) a supercritical CO 2 source comprising supercritical CO 2 and H 2 O, wherein the supercritical CO 2 source is in fluid communication with the reactor and the CO 2 sorbent comprising MgO to allow flow of the supercritical CO 2 and H 2 O between the supercritical CO 2 source and the reactor, thereby allowing contact of CO 2 with the CO 2 sorbent comprising MgO,
wherein the system further comprises a heat source configured to be in fluid communication with the supercritical CO 2 source and the reactor.
2. The system of claim 1 , wherein the ratio of H 2 O to supercritical CO 2 in the supercritical CO 2 source is from 3.6*10 −5 % by weight to 1% by weight.
3. The system of claim 1 , wherein the system further comprises a pump configured to pump supercritical CO 2 from the supercritical CO 2 source towards the heat source and/or reactor.
4. The system of claim 3 , wherein the system further comprises one or more heat exchangers configured to be in fluid communication with the supercritical CO 2 source, the reactor, and the heat source.
5. The system of claim 1 , wherein the system further comprises a turbine configured to be in fluid communication with an outlet of the reactor.
6. The system of claim 1 , wherein the system further comprises a cooling unit configured to be in fluid communication with an outlet of the reactor and the supercritical CO 2 source.
7. The system of claim 4 , wherein the system further comprises a cooling unit configured to be in fluid communication with an outlet of the reactor, the one or more heat exchangers, and the supercritical CO 2 source.
8. The system of claim 1 , wherein the system further comprises a sensible heat storage unit configured to be in fluid communication with the supercritical CO 2 source and the heat source and/or reactor.
9. The system of claim 1 , wherein the reactor is a heat exchange reactor.
10. The system of claim 1 , wherein the heat source is a solar thermal energy source.
11. The system of claim 1 , wherein the system is a closed loop system.
12. A method of storing energy comprising contacting MgCO 3 with supercritical CO 2 having a temperature of at least 450° C. in the presence of H 2 O and/or a carbonate in the system of claim 1 , to thereby store energy.
13. A system for storing energy comprising:
a) a reactor comprising a CO 2 sorbent comprising MgO and a liquid carbonate promoter; and
b) a supercritical CO 2 source comprising supercritical CO 2 , wherein the supercritical CO 2 source is in fluid communication with the reactor and the CO 2 sorbent comprising MgO to allow flow of the supercritical CO 2 between the supercritical CO 2 source and the reactor, thereby allowing contact of CO 2 with the CO 2 sorbent comprising MgO.
14. The system of claim 13 , wherein the ratio of liquid carbonate to MgO in the reactor is from 1% by weight to 50% by weight.
15. The system of claim 13 , wherein the carbonate is selected from the group consisting of sodium carbonate, lithium carbonate, and potassium carbonate, or a mixture thereof.
16. A method of storing energy comprising the steps of:
a) in a reactor, in the presence of H 2 O and/or a carbonate, heating MgCO 3 with supercritical CO 2 having a temperature of at least 450° C., thereby promoting an endothermic chemical reaction to produce CO 2 and MgO; and
b) separating the CO 2 from the MgO.
17. The method of claim 16 , wherein the method further comprises transporting at least a portion of the separated CO 2 to a supercritical CO 2 source via one or more heat exchangers and a cooling unit.
18. The method of claim 16 , wherein the method further comprises step c) in the presence of H 2 O and/or a carbonate, combining supercritical CO 2 having a temperature of less than about 700° C. with the MgO in the reactor, thereby promoting an exothermic chemical reaction to produce heat and MgCO 3 .
19. The method of claim 18 , wherein steps a)-c) are repeated from 1,000 to 20,000 times, wherein the amount of CO 2 that can be reacted with the MgO in step c) throughout the method is at least 50% of the amount of CO 2 that could be reacted with the MgO prior to performing the method.