Fluidized bed and method and system for gas component capture
View Patent ↗The present disclosure is directed to a process that allows dry sorbents to remove a target constituent, such as carbon dioxide (CO 2 ), from a gas stream. A staged fluidized bed separator enables gas and sorbent to move in opposite directions. The sorbent is loaded with target constituent in the separator. It is then transferred to a regenerator where the target constituent is stripped. The temperature of the separator and regenerator are controlled. After it is removed from the regenerator, the sorbent is then transferred back to the separator.
1. A fluidized bed separation system, comprising:
an input to receive a carbon dioxide-containing gas stream;
a plurality of stacked beds fluidized by the gas stream, wherein each of the plurality of stacked beds comprise a solid sorbent to remove the carbon dioxide from the gas stream and form a purified gas stream and a carbon-dioxide loaded sorbent;
a down comer operable to move carbon-dioxide loaded sorbent particles from a first bed of the plurality of stacked beds to a lower second bed of the plurality of stacked beds;
a regenerator to receive, from the first plurality of stacked beds, the carbon dioxide-loaded sorbent, the regenerator comprising a heating device to heat the carbon dioxide-loaded sorbent and remove carbon dioxide from the carbon dioxide-loaded sorbent, thereby forming carbon dioxide-lean solid sorbent for recycle to the first bed and carbon dioxide gas for capture;
first and second cooling devices in the first and second beds, respectively, wherein a heat transfer surface area of the first cooling device is greater than a heat transfer surface area of the second cooling device to remove thermal energy from sorbent regeneration and sorption of carbon dioxide; and
an output for the purified gas stream, wherein the carbon dioxide-containing gas stream flows countercurrently to movement of the carbon-dioxide loaded sorbent particles from the first to the second beds.
2. The system of claim 1 , wherein the first bed comprises the carbon dioxide-lean solid sorbent, wherein the carbon dioxide-lean solid sorbent sorbs the carbon dioxide from a gas phase, and wherein the regenerator comprises:
a second plurality of stacked beds fluidized by a heated fluidization gas, wherein the second plurality of stacked beds comprise the carbon dioxide-loaded solid sorbent;
a down comer operable to move the carbon dioxide-loaded solid sorbent particles from a first bed of the second plurality of beds to a lower second bed of the second plurality of beds; and
an input for the heated fluidization gas, wherein the heated gas flows countercurrently to movement of the carbon dioxide-loaded solid sorbent particles from the first to the second beds of the second plurality of beds.
3. The system of claim 2 , wherein the carbon dioxide-loaded solid sorbent desorbs the carbon dioxide into a gas phase.
4. The system of claim 3 , wherein the fluidization gas is steam and wherein the carbon dioxide-containing gas stream is produced by at least one of a power plant, waste incinerator, and natural gas producer.
5. The system of claim 1 , wherein the carbon dioxide is sorbed by the carbon dioxide lean solid sorbent at a first pressure and temperature and desorbed by the carbon dioxide loaded sorbent under a second set of conditions and wherein at least one of the following is true: (a) a second temperature of the second set of conditions is different from the first temperature, (b) a second pressure of the second set of conditions is different from the first pressure, and (c) a second target constituent partial pressure of the second set of conditions is different from the first partial pressure.
6. The system of claim 1 , wherein the fluidizing step is performed under conditions to produce bubbling bed fluidization and wherein the one of a carbon dioxide-loaded solid sorbent and a carbon dioxide-lean solid sorbent is, under the conditions, a Geldart A material.
7. The system of claim 1 , wherein the sorption of the carbon dioxide by the solid sorbent is exothermic and desorption of the carbon dioxide from the solid sorbent is endothermic.
8. The system of claim 1 , wherein the heat transfer area is a heat exchanger surface area, wherein the first bed has a depth greater than the second bed, and wherein the greater bed depth of the first bed compared to the second bed controls the operating temperature of the first bed, the first bed removing both sensible heat from sorbent regeneration and latent heat from the reaction of the sorbent particles with carbon dioxide in the gas stream.
9. The system of claim 1 , wherein a distributor separates the first and second beds, wherein the distributor comprises plural bubble caps, each bubble cap comprising a body member having plural gas passageways around its circumference to pass the gas stream and a cap member movably positioned on an upper end of the bubble cap, the cap member substantially inhibiting sorbent particles from passing through the gas passageways and through the distributor.
10. A fluidized bed separation system, comprising:
an input to receive a carbon dioxide-containing gas stream;
a plurality of stacked beds fluidized by the gas stream, wherein each of the plurality of stacked beds comprise a solid sorbent to remove the carbon dioxide from the gas stream and form a purified gas stream and a carbon-dioxide loaded sorbent;
a down comer operable to move carbon-dioxide loaded sorbent particles from a first bed of the plurality of stacked beds to a lower second bed of the plurality of stacked beds;
a regenerator to receive, from the first plurality of stacked beds, the carbon dioxide-loaded sorbent, the regenerator comprising a heating device to heat the carbon dioxide-loaded sorbent and remove carbon dioxide from the carbon dioxide-loaded sorbent, thereby forming carbon dioxide-lean solid sorbent for recycle to the first bed and carbon dioxide gas for capture;
first and second cooling devices in the first and second beds, respectively, wherein the first bed has a depth greater than the second bed and wherein the greater bed depth of the first bed compared to the second bed controls the operating temperature of the first bed, the first bed removing both sensible heat from sorbent regeneration and latent heat from the reaction of the sorbent particles with carbon dioxide in the gas stream; and
an output for the purified gas stream, wherein the carbon dioxide-containing gas stream flows countercurrently to movement of the carbon-dioxide loaded sorbent particles from the first to the second beds.
11. The system of claim 10 , wherein a heat transfer surface area of the first cooling device is greater than a heat transfer surface area of the second cooling device to remove both sensible heat and latent heat and wherein the heat transfer area is a heat exchanger surface area.
12. The system of claim 10 , wherein the first bed comprises the carbon dioxide-lean solid sorbent, wherein the carbon dioxide-lean solid sorbent sorbs the carbon dioxide from a gas phase, and wherein the regenerator comprises:
a second plurality of stacked beds fluidized by a heated fluidization gas, wherein the second plurality of stacked beds comprise the carbon dioxide-loaded solid sorbent;
a down comer operable to move the carbon dioxide-loaded solid sorbent particles from a first bed of the second plurality of beds to a lower second bed of the second plurality of beds; and
an input for the heated fluidization gas, wherein the heated gas flows countercurrently to movement of the carbon dioxide-loaded solid sorbent particles from the first to the second beds of the second plurality of beds.
13. The system of claim 12 , wherein the carbon dioxide-loaded solid sorbent desorbs the carbon dioxide into a gas phase.
14. The system of claim 13 , wherein the fluidization gas is steam and wherein the carbon dioxide-containing gas stream is produced by at least one of a power plant, waste incinerator, and natural gas producer.
15. The system of claim 11 , wherein the carbon dioxide is sorbed by the carbon dioxide lean solid sorbent at a first pressure and temperature and desorbed by the carbon dioxide loaded sorbent under a second set of conditions and wherein at least one of the following is true: (a) a second temperature of the second set of conditions is different from the first temperature, (b) a second pressure of the second set of conditions is different from the first pressure, and (c) a second target constituent partial pressure of the second set of conditions is different from the first partial pressure.
16. The system of claim 11 , wherein the fluidizing step is performed under conditions to produce bubbling bed fluidization and wherein the one of a carbon dioxide-loaded solid sorbent and a carbon dioxide-lean solid sorbent is, under the conditions, a Geldart A material.
17. The system of claim 11 , wherein the sorption of the carbon dioxide by the solid sorbent is exothermic and desorption of the carbon dioxide from the solid sorbent is endothermic.
18. A fluidized bed separation system, comprising:
an input to receive a carbon dioxide-containing gas stream;
a plurality of stacked beds fluidized by the gas stream, wherein each of the plurality of stacked beds comprise a solid sorbent to remove the carbon dioxide from the gas stream and form a purified gas stream and a carbon-dioxide loaded sorbent;
a down comer operable to move carbon-dioxide loaded sorbent particles from a first bed of the plurality of stacked beds to a lower second bed of the plurality of stacked beds;
a regenerator to receive, from the first plurality of stacked beds, the carbon dioxide-loaded sorbent, the regenerator comprising a heating device to heat the carbon dioxide-loaded sorbent and remove carbon dioxide from the carbon dioxide-loaded sorbent, thereby forming carbon dioxide-lean solid sorbent for recycle to the first bed and carbon dioxide gas for capture;
first and second cooling devices in the first and second beds, respectively, wherein the first bed has a depth greater than the second bed, wherein a heat transfer surface area of the first cooling device is greater than a heat transfer surface area of the second cooling device to remove both sensible heat and latent heat, and wherein the greater bed depth of the first bed compared to the second bed and the greater heat transfer surface area of the first bed compared to the second bed controls the operating temperature of the first bed, the first bed removing both sensible heat from sorbent regeneration and latent heat from the reaction of the sorbent particles with carbon dioxide in the gas stream; and
an output for the purified gas stream, wherein the carbon dioxide-containing gas stream flows countercurrently to movement of the carbon-dioxide loaded sorbent particles from the first to the second beds.
19. The system of claim 18 , wherein the heat transfer area is a heat exchanger surface area.