Removal of carbon dioxide from air
OwnerKlaus S. Lackner, Allen B. Wrightinventors
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Abstract
The present invention provides a method and apparatus for removing a contaminant, such as carbon dioxide, from a gas stream, such as ambient air. The contaminant is removed from the gas stream by a sorbent which may be regenerated using a humidity swing, a thermal swing, or a combination thereof. The sorbent may comprise a substrate having embedded positive ions and individually mobile negative ions wherein the positive ions are sufficiently spaced to prevent interactions between the negative ions. Where a thermal swing is used, heat may be conserved by employing a heat exchanger to transfer heat from the regenerated sorbent to an amount of sorbent that is loaded with the contaminant prior to regeneration.
Claims26
1-18. (canceled)
A method for extracting a contaminant from a gas stream, comprising the steps of:
- a) bringing the gas stream in contact with a sorbent which captures the contaminant from the gas stream, so as to at least partially saturate the sorbent with contaminant;
- b) placing the contaminant carrying sorbent in a regeneration unit for releasing the contaminant from the sorbent and regenerate the sorbent, wherein the regeneration unit is maintained at a temperature that is higher than the temperature of the gas stream;
- c) removing the regenerated sorbent from the regeneration unit;
- and
- d) capturing heat from the regenerated sorbent as the sorbent is removed from the regeneration unit.
(canceled)
27-29. (canceled)
An apparatus for extracting a contaminant from a gas stream using a sorbent employing a thermal swing, comprising:
- a sorbent for capturing the contaminant;
- a capture unit, wherein the sorbent is exposed to the gas stream and becomes at least partially saturated with the contaminant;
- a regeneration unit, wherein the sorbent is exposed to elevated temperatures thereby causing the sorbent to release the contaminant according to a thermal swing;
- and
- a heat exchanger for extracting heat retained from the sorbent in the regeneration unit.
(canceled)
(canceled)
40-41. (canceled)
A method for extracting CO2 from a gas stream comprising the steps of:
- (a) bringing a sorbent in contact with said gas stream, so as to at least partially saturate said sorbent with CO2;
- (b) releasing CO2 from said sorbent at a temperature that is higher than the temperature of said gas stream, thereby regenerating said sorbent;
- (c) capturing heat retained by said sorbent using a working fluid;
- and
- (d) recycling captured heat for use in step (b).
Dependencies are inferred from the claim text.