Carbon dioxide sorbents and structures, methods of use, and methods of making thereof

Abstract

Embodiments of the invention a method for producing a composite paper by providing a particulate sorbent, providing a paper pulp, and mixing the particulate sorbent and the paper pulp to develop a mixture. The method includes producing an article from the mixture that includes the particulate sorbent at least partially distributed through at least a portion of the article. Further, the at least one article is configured and arranged to uptake and release carbon dioxide as a function of moisture content. Some embodiments of the invention include a composite paper-like assembly including at least a first and second layer including hydrophobic fibers, and sorbent particles and/or a sorbent loaded paper sandwiched between the first and second porous sheets. Some further embodiments include a method for producing a material that supports a moisture swing by providing a material including activated carbon, and infusing the activated carbon with ionic salt.

Claims

1. A composite paper-like assembly comprising: at least a first and second layer including hydrophobic fibers; and at least one of sorbent particles and a sorbent loaded paper sandwiched between the first and second layers.

2. The assembly of claim 1, wherein the at least one of sorbent particles or sorbent loaded paper include activated carbon.

3. The assembly of claim 2, wherein at least a portion of the activated carbon includes infused ions, the ions including at least one of hydroxide ions, carbonate ions, and bicarbonate ions.

4. The assembly of claim 1, wherein the at least one of sorbent particles or sorbent loaded paper includes at least one salt of at least one of a hydroxide, carbonate, and bicarbonate.

5. The assembly of claim 1, further comprising at least one of a honey-comb-like monolith, a tube, fibers, mesh, and felt-like material.

6. The assembly of claim 1, wherein the at least one particulate sorbent comprises at least one carbonate or bicarbonate salt.

7. The assembly of claim 6, wherein the carbonate or bicarbonate salt comprises at least one of a sodium and a potassium salt.

8. The assembly of claim 7, wherein the carbonate or bicarbonate salt is at least partially distributed, mixed, impregnated or infused into activated carbon.

9. A composite paper-like assembly comprising: at least a first and second layer, each layer being porous and comprising hydrophobic fibers; and at least one of sorbent particles and a sorbent loaded paper sandwiched between the first and second layers.

10. The assembly of claim 9, wherein the at least one of sorbent particles and sorbent loaded paper comprises a carbon dioxide sorbent.

11. The assembly of claim 10, wherein the carbon dioxide sorbent exhibits a change in uptake and release of carbon dioxide based at least in part on exposure to liquid water.

12. The assembly of claim 10, wherein the carbon dioxide sorbent exhibits a change in uptake and release of carbon dioxide based at least in part on exposure to water vapor or humidity.

13. The assembly of claim 9, wherein the at least one of sorbent particles or sorbent loaded paper include activated carbon.

14. The assembly of claim 13, wherein at least a portion of the activated carbon includes infused ions, the ions including at least one of hydroxide ions, carbonate ions, and bicarbonate ions.

15. The assembly of claim 9, wherein the at least one of sorbent particles or sorbent loaded paper includes at least one salt of at least one of a hydroxide, carbonate, and bicarbonate.

16. A composite paper-like assembly comprising: at least a first and second layer including hydrophobic fibers; and at least one of sorbent particles and a sorbent loaded paper sandwiched between the first and second layers, wherein the at least one of sorbent particles and sorbent loaded paper comprises a carbon dioxide sorbent.

17. The assembly of claim 16, wherein the carbon dioxide sorbent exhibits a change in uptake and release of carbon dioxide based at least in part on exposure to liquid water.

18. The assembly of claim 16, wherein the carbon dioxide sorbent exhibits a change in uptake and release of carbon dioxide based at least in part on exposure to water vapor or humidity.

19. The assembly of claim 16, wherein the at least one particulate sorbent comprises at least one carbonate or bicarbonate salt.

20. The assembly of claim 19, wherein the carbonate or bicarbonate salt comprises at least one of a sodium and a potassium salt.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an image of a moisture swing material in accordance with some embodiments of the invention.

(2) FIG. 2 shows an image of a moisture swing material formed as a filter in accordance with some embodiments of the invention.

(3) FIG. 3 shows an image of a moisture swing assembly in accordance with some embodiments of the invention.

(4) FIG. 4 shows an image of a plurality of moisture swing assemblies in accordance with some embodiments of the invention.

(5) FIG. 5 illustrates a humidity swing comparison plot in accordance with some embodiments of the invention.

(6) FIG. 6 shows a plot of sample mass and CO.sub.2 as a function of dew point in accordance with some embodiments of the invention.

DETAILED DESCRIPTION

(7) Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms mounted, connected, supported, and coupled and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, connected and coupled are not restricted to physical or mechanical connections or couplings.

(8) The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives that fall within the scope of embodiments of the invention.

(9) In the following description, the terms moisture swing and humidity swing are used nearly interchangeably, with a small difference in emphasis. A moisture swing emphasizes the possibility that the water is brought in contact with the sorbent as a liquid, whereas the humidity swing is more focused on the case of water vapor getting in contact with the sorbent.

(10) Some embodiments of the invention include methods and systems for producing carbon dioxide sorbents and structures. Embodiments of the invention extend beyond conventional air capture technology that uses off-the-shelf gas separation technologies extrapolated to extremely low carbon dioxide concentrations. Some embodiments include the use of humidity or moisture to induce the unloading of carbon dioxide from one or more sorbents that offer a distinctly different path to extracting carbon dioxide from air. Using one or more of the embodiments described herein offers an opportunity to separate a low concentration gas from a mixture that can include low carbon dioxide concentrations. Some embodiments include sorbents that exhibit a moisture swing when liquid water is brought in contact with the sorbent, whereas other embodiments include a humidity swing in the case of water vapor contacting the sorbent. Some embodiments include materials, composites or assemblies that exhibit a moisture swing and a humidity swing.

(11) There are a number of different ways to create composite materials that contain a large amount of sorbent material embedded as small particles into a different material. The composite material in turn could be suitably shaped into a superstructure to produce efficient air filters that maximize the contact between sorbent and carbon dioxide in the air. Shapes that have been considered include, but are not limited to, the following: flat, sheets, honey-comb like monoliths, packages of thin tubes (akin to drinking straws), thin fibers forming meshes, or lose felt-like structures as seen in some glass-fiber furnace filters. The purpose of the secondary material is to hold the sorbent particles in place and allow them to change shape in the presence of water, while at the same time maximizing access of air to the resin particles. Until a sorbent material has been found that is either sufficiently elastic to absorb strains of the expansion in the presence of water, or that simply does not change volume in the presence of water, the strategy for making better materials involves composites.

(12) Some embodiments of the invention include paper composites. In some embodiments, the use of a paper matrix can allow for very fine particles with rapid uptake, and with low mass. For example, various moisture swing sorbents can be ground finely and used as filler in making conventional paper materials. Some embodiments include the use of conventional papermaking techniques for producing humidity swing sorbents in the form of thin paper or paper mache structures. Paper can be generated rapidly and cheaply with sorbent powders attached to the paper structure, taking advantage of the cohesion between fibers and sorbent particles to attach very small particles to the fibrous structure of the paper. This concept can be extended from conventional paper fibers to any fibers to which sorbent particles stick. In the case of conventional paper fibers, the presence of hydroxyl groups on their surfaces help creating cohesion. By creating fresh pulp from spent sorbent paper, the valuable resin can be collected and separated from the fiber. Further, in some embodiments, additives such as sodium hydroxide (NaOH) can be used in this separation process. These techniques can also be extended to other paper like materials. In some embodiments, moisture can absorb on paper, and paper and resin particles adhere.

(13) FIG. 1 shows an image of a moisture swing material 100 in accordance with some embodiments of the invention. Further, FIG. 2 shows an image of a moisture swing material formed as a filter 200 in accordance with some embodiments of the invention. In some embodiments, conventional artisan paper kits can be used to produce sheets of paper made from paper pulp (i.e., paper pulp from paper). In some embodiments, by adding finely ground sorbent to paper pulp, flat sheets of active sorbent material can be fabricated that show high uptake rate and high release rates of carbon dioxide in a conventional humidity swing. In some embodiments, the materials include up to 50% by weight of sorbent material. Further, for a particular mass of adsorbent material, the performance can be significantly better than when compared with particles embedded in polypropylene (e.g., Snowpure-based membranes). The much smaller particle size in the paper material can contribute strongly to the enhanced performance. Furthermore, microscopic analysis can show the fibrous structure of paper is far more open than the pore structure in polypropylene (of the Snowpure membrane materials), and thus allows access of air to the sorbent particles with less hindrance. However, the hygroscopic nature of the paper leads to additional water absorption on the supporting structure that does not directly contribute to the moisture swing process.

(14) Some embodiments of the invention includes methods and systems for producing carbon dioxide sorbents and structures including paper composites with sorbent powders attached to the paper structure, enclosed within the structure, or both. Some embodiments include composite materials that use highly hydrophobic but porous sheets to protect resin powders from direct contact with water. Each sheet can be a solid flat surface with small pores. Each sheet can be made from binding together a large number of matted fibers. In some embodiments, sorbents including resin powders can be embedded in small pouches between two plies of hydrophobic porous sheets. Further, in some embodiments, resin powders can be mixed with the fibers and held in place by a felt-like fibrous mat. In some further embodiments, a sheet-like sorbent can be created by mixing fibers and sorbent particles into a flat sheet that is bound together by heat treatment such as hot rolling. In some embodiments, the powder and fibers can be deposited onto the rollers so that the outside surfaces of the sheet contain minimal amount of sorbent. In this instance, the material or assembly can be a 3-ply structure with hydrophobic fibers on the top and bottom and sorbent particles in the middle, e.g., two hydrophobic porous sheets sandwiching a sorbent loaded paper on the inside. In some embodiments, the resin can be held in place by hydrophilic fibers (e.g. paper fibers) that prevent particles from drifting through the hydrophobic matrix.

(15) Some embodiments include the use of commercial composites including Tyvek brand composites comprising highly hydrophobic and porous sheets that protect embedded or enclosed sorbents (e.g., including resin powders and/or activated carbon with carbonate ions embedded into the carbon structure) from direct contact with water. Tyvek is a registered trademark of DuPont Corporation. At atmospheric pressures, water cannot pass through an enclosure comprising a polyolefin fiber material because capillary forces can prevent water from passing into and through the pores of the material. However, at sufficient pressure, the capillary forces can be overcome and can push water or brine successfully through the material. Some embodiments include a method for removing contamination from the sorbent by driving brines rich in carbonate, bicarbonate or hydroxide ions, through the hydrophobic barrier by high pressure flows. It is therefore possible to regenerate a sorbent material that has been exposed to other ions and thus has become deactivated as a carbon dioxide sorbent. For example, it is possible for the sorbent to remove SO.sub.2 and NO.sub.x from the atmosphere thereby reducing its carbon dioxide capacity. By forcing carbonate brine through the polyolefin material, it is possible to regenerate an enclosed sorbent by washing out the contaminating ions without the need to rupture or otherwise physically damage the surface of the enclosure.

(16) Tyvek comprises a polyolefin fiber material formed or converted into a paper-like material. In some embodiments, Tyvek materials, Tyvek-based materials, or Tyvek-like materials can be used to form an enclosure and/or at least a partially sealed packet of sorbent material (hereinafter called an assembly). Some embodiments of the invention include composite paper-like materials having fibrous but extremely hydrophobic materials like Tyvek. In order to enable matted fibers that stick to each other and bind into a strong paper like material, polyolefin fibers can be pressed together using heat (e.g., hot rollers) that result in a surface melting and binding together the overall matrix. The properties, features, or characteristics of Tyvek useful for some embodiments of the invention include (1) it can be spun into very fine fibers, (2) the fibers are highly hydrophobic, and (3) there is a known defined temperature at which the fibers pressed together will stick to each other.

(17) In some embodiments, a Tyvek sheet can be separated into two plies, each one having one of the smooth surfaces outside, and the interior being less well bound. The material can be heated at or near the surface resulting in a flat tightly bound fibrous mat. On the inside of the material, the number of contact points between fibers is lower that at or near the outer surface, and the material appears fuzzy. Using the materials as described above, enclosures or pouches can be formed into which sorbent material can be enclosed and at least partially sealed.

(18) In some other embodiments, equivalent materials can be used in place of, or in addition to the Tyvek material. In some embodiments, the enclosure or pouch can comprise felt-like paper structures. In some embodiment, the enclosure or pouch material can be highly hydrophobic. In some embodiments, the enclosure or pouch material can comprise porous or semi-porous sheets. In some embodiments, the enclosure or pouch material can protect one or more enclosed sorbent materials from wind, water, contamination, or a combination thereof. In some embodiments, the enclosure or pouch can prevent one or more enclosed sorbents (e.g., such as sorbents in powdered form) from blowing away or otherwise being distributed or physically disturbed. Moreover, the enclosure or pouch can keep liquid water away from sorbent while at the same time, allowing water vapor to pass through the enclosure or pouch material. In this instance, the transfer from liquid water to the enclosed sorbent is fast, and heat transfer occurs over fractions of a millimeter. For example, FIG. 3 shows an image of a moisture swing assembly 300 in accordance with some embodiments of the invention. In some embodiments, the moisture swing assembly 300 can comprise an upper and a lower layer enclosing an embedded material 305. The embedded material 305 can comprise at least one sorbent material. In some embodiments, the upper portion of the enclosed can comprise a single piece of Tyvek or Tyvek-type material or can be composed of at least two or more layers or sections of Tyvek material coupled together at selected regions.

(19) In some embodiments of the invention, the enclosure or pouch material can comprise one or more polymer fibers. For example, some embodiments include polyolefin fibers. In some embodiments, the enclosure or pouch can include spun, non-woven fiber material (e.g., such as Tyvek). Further, in some embodiments, the enclosure or pouch material can comprise thermally welded fibers of high density polyethylene (HDPE). In other embodiments, the enclosure or pouch can comprise spun, non-woven fiber material, and/or thermally welded fibers of polypropylene. In some further embodiments, the enclosure or pouch can comprise other polymers, including, but not limited to any conventional porous three-dimensional non-woven polymer matrices. In some other embodiments, the enclosure or pouch can comprise porous woven polymer matrices comprising polymer fibers and/or non-fiber particles.

(20) In some embodiments, the sorbent can comprise an activated carbon. Some embodiments comprise a carbonate brine. Some embodiments include carbon impregnated with carbonate.

(21) FIG. 4 shows an image of a plurality of moisture swing assemblies 400 in accordance with some embodiments of the invention. A single sheet of sorbent material 410 is shown comprising resin infused paper. In comparison, some embodiments include assembly 420 including embedded material 425 comprising potassium carbonate. In some further embodiments, assembly 430 includes embedded material 435 comprising sodium carbonate.

(22) In some other embodiments, assembly 440 includes embedded material 445 comprising an activated carbon such as Norit RBAA 1. In other embodiments, Darco G60 can be used. For example, in some embodiments, assembly 460 includes embedded material 465. Darco is a registered trademark of Norit Americas, Inc. Some further embodiments include Norit activated carbon. Norit is a registered trademark of Norit N.V.

(23) Some embodiments include materials and assemblies with humidity swing processes with activated carbon with carbonate ions embedded into the carbon structure. Some embodiments include using hydroxide, carbonate, or bicarbonate solutions to impregnate activated carbon with salts that promote a humidity swing. Some embodiments include using the humidity swing for feeding carbon dioxide to photosynthesizing organisms by releasing carbon dioxide capture from ambient air and enriching it by a factor 2 to 20. Some embodiments include using the humidity swing with ion impregnated activated carbon for feeding carbon dioxide to photosynthesizing organisms. For example, using these materials, and releasing carbon dioxide capture from ambient air and maintaining a carbon dioxide level in an enclosure against the removal of carbon dioxide by a living organism, with the level ranging from below ambient to the maximum level achievable by the sorbent (at present up to 20 times higher). For example, in some embodiments, enclosure or pouches can include a sorbent that can comprise a carbonate and activated carbon combination, such as a mixture or composite of activated carbon and carbonate. Some embodiments include infusing activated carbon with potassium or sodium carbonate to produce a material that supports a moisture swing. Within the enclosures, individual materials of activated carbon, sodium carbonate and potassium carbonate can absorb carbon dioxide but show no moisture swing behavior. However, activated carbon infused with potassium (or sodium) carbonate does show a pronounced moisture swing. For example, in some further embodiments, assembly 450 includes embedded material 455 comprising an activated carbon such as Norit RBAA 1 and sodium carbonate. In some further embodiments, assembly 470 includes embedded material 475 comprising an activated carbon such as Darco G60 and sodium carbonate. In some embodiments, the enclosues or pouches can include more than one type of activated carbon and/or more than one carbonate. For example, some embodiments include mixtures of sodium and potassium carbonates. In other embodiments, other carbonates can be including, either alone or within mixtures of other carbonates and/or with one or more activated carbon materials.

(24) In some embodiments, any of the enclosures or pouches described earlier can be subjected to a humidity swing depending on the exposed atmosphere. When using an enclosure comprising a polyolefin sheet, the enclosure is impermeable to liquid water, while being open to water vapor transmission. As a result, the enclosures or pouches can provide a complete humidity swing, with minimal obstruction from the surface that covers them. Since liquid water does not penetrate through the surface of the enclosure, the humidity swing can be induced by exposing the outside surface to salty or similarly contaminated water. The presence of the water can induce water vapor to cross the barrier, and thus cause a humidity swing within the enclosed sorbent. In some embodiments comprising a polyolefin barrier material, the material does not wet, and does not adsorb any water. Therefore, exposing the sorbent protected by a polyolefin porous barrier to water results in a controlled and minimum uptake of water. In some embodiments, an air capture system based on this concept can minimize its water consumption to what is necessary to drive the humidity swing.

(25) FIG. 5 shows a humidity swing comparison plot 500 with a comparison of an ion exchange membrane (Snowpure), a snowpure membrane enclosed in a Tyvek enclosure, and assembly 440 including embedded material 445 comprising an activated carbon such as Norit RBAA 1 in accordance with some embodiments of the invention. For example, data lines 525, 527, 529 show CO.sub.2 concentration as a function of time for Snowpure ion exchange membrane (with no enclosure), Snowpure ion exchange membrane enclosed in Tyvek, and Norit RBAA 1 activated carbon in a Tyvek enclosure. Data line 550 shows the corresponding dew point (show contiguously for each of the corresponding data lines 525, 527, 529). FIG. 6 shows a plot of sample mass and CO.sub.2 as a function of dew point in accordance with some embodiments of the invention, where data line 625 represents CO.sub.2 concentration, and data line 650 shows the corresponding sample mass as a function of time.

(26) Any of the embodiments disclosed herein can offer advantages of conventional technologies, including, but not limited to: can be used in advanced air capture technologies; can allow the production of granular CO.sub.2 sorbents; can be regenerated with contaminated water; can be regenerated with salty water; and are less expensive and safer materials for sorbents; offer protection of sorbent from contaminants; and can offer water vapor transparent which protects sorbent from liquid water.

(27) Although the invention has been described and illustrated with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without parting from the spirit and scope of the present invention. Accordingly, other embodiments are within the scope of the following various embodiments. It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. Various features and advantages of the invention are set forth in the following claims.