Sorbents for carbon dioxide reduction from indoor air

• US 9,533,250 B2
• Filed: 05/17/2012
• Issued: 01/03/2017
• Est. Priority Date: 08/23/2011
• Status: Active Grant

• Current Assignee: Enverid Systems, Inc.
• Original Assignee: Enverid Systems, Inc.
• Inventors: Meirav, Udi, Biran, Israel
• Primary Examiner(s): Jones, Christopher P
• Application Number:
  US14/117,797
• Publication Number:
  US 20140298996A1
• Time in Patent Office: 1,692 Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2252/204 Amines
• CPC Class Codes: B01D 2253/11 Clays
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 2259/4508 for cleaning air in buildings
• CPC Class Codes: B01D 2259/4575 in aeroplanes or space ships
• CPC Class Codes: B01D 53/025 with wetted adsorbents; Chromatography analytical chromatography G01N30/00 - G01N30/96; for liquids B01D15/08
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01J 20/12 Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3248 the functional group or the linking, spacer or anchoring group as a whole comprising at least one type of heteroatom selected from a nitrogen, oxygen or sulfur, these atoms not being part of the carrier as such
• CPC Class Codes: B01J 20/3272 Polymers obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

A sorbent for CO₂ reduction from indoor air from an enclosed space. In some embodiments, the sorbent comprises a solid support and an amine-based compound being supported by the support. The sorbent captures at least a portion of the CO₂ within the indoor air. The sorbent may be regenerated by streaming outdoor air through the sorbent to release at least a portion of the captured CO₂. The sorbent is structured to allow indoor air to flow therein with relatively low flow resistance and relatively rapid reaction kinetics. Regeneration may be performed at relatively low outdoor air temperatures, thereby minimizing the thermal energy required for regenerating the sorbent.

Claims

1. A sorbent for reduction of CO₂ from air of an enclosed space, comprising:

a support comprising a plurality of solid particles having an average diameter dimension in the range of 0.1-10 millimeters; and

an amine-based compound, wherein at least 25% of amine functional groups are secondary amines, being supported by the support,

wherein the amine-based compound comprises a polyamine having between 25%-75% of secondary amines,

wherein the support is impregnated with a solution of the amine-based compound, wherein the solution of the amine-based compound comprises water; and

wherein the amine-based compound is configured to capture at least some of the CO₂ within the indoor air of the enclosed space and release at least a portion of the captured CO₂ by streaming outdoor air through the sorbent.

2. A sorbent according to claim 1, wherein the support comprises clay.

3. A sorbent according to claim 1, wherein the support is selected from the group consisting of:

gels, molecular sieves, nanotube-containing materials, porous materials, sponge and sponge-like materials, electro-magnetically charged objects, porous organic polymers, ion exchange resins, polymeric absorbent resins, acrylic ester polymers, polystyrene divinyl benzene, polymethyl methacrylate (PMMA), polystyrene, styrene divinylbenzene (SDB), fly ash, activated carbon, carbon nanotubes, alumina nanoparticles, synthetic zeolite, porous alumina, porous minerals, porous silica, silica nanoparticle, fumed silica, activated charcoal, aluminum phyllosilicates, bentonite, montmorillonite, ball clay, fuller'"'"'s earth, kaolinite, attapulgite, hectorite, palygorskite, saponite, sepiolitemetal, organic frameworks, and one or more combinations thereof.

4. A sorbent according to claim 1, wherein the support comprises a plurality of particles with an average diameter dimension in the range of 0.2-3 millimeters.

5. A sorbent according to claim 1, wherein the support comprises a plurality of particles with an average diameter dimension in the range of 0.3-1 millimeters.

6. A sorbent according to claim 1, wherein the support is selected from the group consisting of:

granules, beads, pellets, extrudates and one or more combinations thereof.

7. A sorbent according to claim 1, comprising the amine-based compound wherein at least 50% of amine functional groups are secondary amines.

8. A sorbent according to claim 1, wherein the amine-based compound further comprises monoethanolamine (MEA), ethanolamine, methylamine, branched polyethyleneimine (PEI), linear polyethyleneimine (PEI), diethanolamine (DEA), dimethylamine, diethylamine, diisopropanolamine (DIPA) tetraethylenepentamine (TEPA), methyldiethanolamine (MDEA), methylethanolamine, or a combination thereof.

9. A sorbent according to claim 1, wherein the support is formed with a large total surface area.

10. A sorbent according to claim 1, wherein the indoor air comprises a CO₂ concentration of about 400 to about 5000 ppm.

11. A sorbent according to claim 1, wherein a CO₂ concentration in the outdoor air, prior to being streamed into the sorbent, is approximately about 300 to about 500 ppm.

12. A sorbent according to claim 1, wherein the outdoor air has a CO₂ concentration which is lower than the CO₂ concentration in the indoor air by substantially less than about 1600 ppm.

13. A sorbent according to claim 1, wherein the support comprises particles, fine particles or a powder based solid, and wherein the fine particles are agglomerated into larger particles so as to facilitate air flow through the sorbent.

14. A sorbent according to claim 1, wherein outdoor air is streamed through the sorbent at a temperature lower than about 100°

C.

15. A sorbent according to claim 1, wherein outdoor air is streamed through the sorbent at a temperature lower than about 80°

C.

16. A sorbent according to claim 1, wherein outdoor air is streamed through the sorbent at a temperature lower than about 60°

C.

17. A sorbent according to claim 1, wherein outdoor air is streamed through the sorbent at a temperature lower than about 50°

C.

18. A sorbent according to claim 1, wherein the sorbent is disposed in an HVAC system for removal of CO₂ from the indoor air within the HVAC system.

23. A sorbent according to claim 1, wherein the amine-based compound further comprises a mixture of diethanolamine (DEA) and any other amine or compound.

24. A sorbent of claim 1, wherein the support is impregnated by the amine-based compound with additional mechanical stimulation, with catalysts, or with external energy sources, such as heat.

19. A sorbent for reduction of CO₂ from air of an enclosed space, comprising:

a support comprising a porous solid fiber-based material intertwined to form a fabric or paper-like material; and

an amine-based compound, wherein at least 25% of amine functional groups are secondary amines, being supported by the support,

wherein the amine-based compound comprises a polyamine having between 25%-75% of secondary amines,

wherein the sorbent is impregnated with a solution of the amine-based compound, wherein the solution of the amine-based compound comprises water; and

wherein the amine-based compound is configured to capture at least some of the CO₂ within the indoor air of the enclosed space and release at least a portion of the captured CO₂ by streaming outdoor air through the sorbent.

20. A sorbent according to claim 19, wherein the support comprises a plurality of sheets.

21. A sorbent according to claim 20 wherein the support comprises a plurality of sheets with a thickness in the range of one micron to two centimeters.

22. A sorbent according to claim 19 wherein the support comprises a plurality of sheets with a thickness in the range of 2 to 80 millimeters.

25. A sorbent for reduction of CO2 from air of an enclosed space, comprising:

a support comprising a plurality of solid particles having an average diameter dimension in the range of 0.1-10 millimeters; and

an amine-based compound comprising a polyamine having between 25%-75% of secondary amines and a solvent, wherein the solvent is water, and

wherein the amine-based compound is configured to capture at least some of the CO2 within the indoor air of the enclosed space and release at least a portion of the captured CO2 by streaming outdoor air through the sorbent.

26. A sorbent for reduction of CO2 from air of an enclosed space, comprising:

a support comprising a plurality of solid particles having an average diameter dimension in the range of 0.1-10 millimeters; and

an amine-based compound comprising a polyamine having between 25%-75% of secondary amines and a solvent, wherein the solvent is water,

wherein the support impregnated with the amine-based compound is not further dried, and

wherein the amine-based compound is configured to capture at least some of the CO2 within the indoor air of the enclosed space and release at least a portion of the captured CO2 by streaming outdoor air through the sorbent.