Nanofibers structured composites and shaped composites for carbon dioxide separation and removal applications

Abstract

Disclosed is a media for capturing carbon dioxide from a gas stream of ambient air or industrial exhaust. The media includes a fiber matrix having fine fiber strands formed from at least one first polymer capable of capturing carbon dioxide through absorbance or adsorbance. The fine fiber strands have a first mean diameter of 5000 nm or less. Further, the media includes a plurality of nodules dispersed in the fiber matrix, and the plurality of nodules are made from a nodule material capable of capturing carbon dioxide through absorbance or adsorbance. The media can be configured for use in a carbon capture element of a carbon capture cell disposed within a carbon capture system, such as a direct air or point source carbon capture system.

Description

NANOFIBERS STRUCTURED COMPOSITES AND SHAPED COMPOSITES FOR CARBON DIOXIDE SEPARATION AND REMOVAE APPLICATIONSCROSS-REFERENCE TO RELEATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 652,958, filed on May 29, 2024, the entire contents of which are incorporated herein by reference thereto.FIELD OF THE INVENTION

[0002] This invention generally relates to a carbon capture element and, in particular, to a carbon capture media including fine fiber strands formed from a carbon capture material.BACKGROUND OF THE INVENTION

[0003] Reducing carbon dioxide emissions has been an important environmental mission for many years. A variety of promising techniques have been proposed to address the production of carbon dioxide by various processes, including power generation and production of certain products. One emerging technology is carbon capture. During carbon capture, carbon dioxide is removed from a gas stream of environmental air or industrial exhaust, and the gas stream with a reduced carbon dioxide concentration is released. The captured carbon dioxide is stored, preventing its release into the atmosphere.BRIEF SUMMARY OF THE INVENTION

[0004] In a first aspect, embodiments of the present disclosure relate to a media for capturing carbon dioxide from a gas stream of ambient air or industrial exhaust. The media comprises a fiber matrix comprising fine fiber strands formed from at least one first polymer capable of capturing carbon dioxide through absorbance or adsorbance. The fine fiber strands have a first mean diameter of 5000 nm or less. Further, the media comprises a plurality of nodules dispersed in the fiber matrix, and the plurality of nodules comprise a nodule material capable of capturing carbon dioxide through absorbance or adsorbance.

[0005] In a second aspect, embodiments of the present disclosure relate to the media of the first aspect in which the first mean diameter of the fine fiber strands is 2500 nm or less.

[0006] In a third aspect, embodiments of the present disclosure relate to the media of the first aspect or the second aspect in which the first mean diameter of the fine fiber strands is 1000 nm or less.

[0007] In a fourth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the third aspect in which the fine fiber strands are crosslinked.

[0008] In a fifth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the fourth aspect in which the at least one first polymer is selected from a group consisting of polyethyleneimine, ethylenediamine, tetra-ethylenepentamine, diethanolamine, diethylenetriamine, tris(2-aminoethyl)amine, penta-ethylenehexamine, and combinations thereof.

[0009] In a sixth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the fifth aspect in which the fiber matrix further comprises second fiber strands of at least one second polymer configured to provide mechanical support for the fine fiber strands. The second fiber strands have a second mean diameter that is greater than the first mean diameter.

[0010] In a seventh aspect, embodiments of the present disclosure relate to the media of the sixth aspect in which the second mean diameter of the second fiber strands is in a range from 1 pm to 25 pm.

[0011] In an eighth aspect, embodiments of the present disclosure relate to the media of the sixth aspect or the seventh aspect in which the second mean diameter of the second fiber strands is in a range from 2.5 pm to 15 pm.

[0012] In a ninth aspect, embodiments of the present disclosure relate to the media of one of the sixth aspect through the eighth aspect in which the at least one second polymer is selected from a group consisting of a polyamide, a polyacrylonitrile, a cellulosic material, apolyvinyl alcohol, a polyvinyl chloride, a polyvinylpyrrolidone, a chitosan, a polytmethyl methacrylate), a polyacrylamide, and combinations thereof.

[0013] In a tenth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the ninth aspect in which the nodule material is selected from a group consisting of an amine-loaded sorbent, graphene, carbon nanotubes, activated carbon, honeycomb monolith, a hybrid crystalline matenal. a zeolite, a silica, a silica-alumina, and combinations thereof.

[0014] In an eleventh aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the tenth aspect in which the plurality of nodules comprises a mean diameter in a range of 250 nm to 20 pm.

[0015] In a twelfth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the eleventh aspect in which the plurality of nodules comprises a mean diameter in a range of 1 pm to 10 pm.

[0016] In a thirteenth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the twelfth aspect in which the media further comprises a non-woven scrim.

[0017] In a fourteenth aspect, embodiments of the present disclosure relate to the media of the thirteenth aspect in which the non-woven scrim is formed from a third polymer selected from a group consisting of a polypropylene, a polyethylene, a polyacrylonitrile, a polyamide, a polyvinyl chloride, and combinations thereof.

[0018] In a fifteenth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the fourteenth aspect in which the first polymer comprises a polymer with an amine functional group.

[0019] In a sixteenth aspect, embodiments of the present disclosure relate to the media of one of the first aspect through the fifteenth aspect in which the nodule material comprises a polymer with an amine functional group.

[0020] In a seventeenth aspect, embodiments of the present disclosure relate to a carbon capture element comprising the media according to any of the first aspect to the sixteenth aspect.

[0021] In an eighteenth aspect, embodiments of the present disclosure relate to a carbon capture element according to the seventeenth aspect in which the media is wound in layers to form a tubular structure.

[0022] In a nineteenth aspect, embodiments of the present disclosure relate to a carbon capture element according to the seventeenth aspect in which a first sheet of the media is corrugated and a second sheet of the media is flat. The first sheet and the second sheet are wound around a central core in layers to form a plurality of longitudinal channels.

[0023] In a twentieth aspect, embodiments of the present disclosure relate to a carbon capture element according to the nineteenth aspect in which about half of the longitudinal channels are plugged with resin at a first end and the remaining longitudinal channels are plugged with resin at a second end opposite the first end.

[0024] In a twenty-first aspect, embodiments of the present disclosure relate to a carbon capture element according to the seventeenth aspect in which the carbon capture element comprises a core, the media wound in layers around the core, and a first end cap. The media and the core are potted into the first end cap at a first end of the carbon capture element.

[0025] In a twenty-second aspect, embodiments of the present disclosure relate to a carbon capture element according to the twenty-first aspect in which the core is a perforated metal core or a polymeric cage.

[0026] In a twenty -third aspect, embodiments of the present disclosure relate to a carbon capture element according to the twenty-first or the twenty -second aspect in which the carbon capture element further comprises a second end cap. The media and the core are potted into the second end cap at a second end of the carbon capture element opposite to the first end.

[0027] In a twenty-fourth aspect, embodiments of the present disclosure relate to a carbon capture cell. The carbon capture cell comprises a cell plate comprising a first surface and a second surface. The second surface being opposite to the first surface. The carbon capture cell further comprises a plurality of apertures formed through the cell plate from the first surface to the second surface. The carbon capture cell further comprises plurality of support structures. Each support structure of the plurality of support structures extends form the second surface of the cell plate around each aperture of the plurality of apertures. Further, the carbon capture cell comprises a plurality of carbon capture elements according to any of the seventeenth aspect through the twenty-third aspect, and each carbon capture element of the plurality of carbon capture elements is disposed on a support structure of the plurality of support structures.

[0028] In a twenty -fifth aspect, embodiments of the present disclosure relate to a method of reducing a concentration of carbon dioxide in a gas stream. In the method, the gas stream having a first concentration of carbon dioxide is flowed through the media according to any of the first aspect through the sixteenth aspect from a first side to a second side. The carbon dioxide is absorbed or adsorbed in the media such that a second concentration of the carbon dioxide on the second side of the media is less than the first concentration of carbon dioxide on the first side of the media.

[0029] In a twenty-sixth aspect, embodiments of the present disclosure relate to the method of the twenty-fifth aspect in which the gas stream is ambient air and the first concentration of carbon dioxide is in a range of 300 ppm to 500 ppm.

[0030] In a twenty -seventh aspect, embodiments of the present disclosure relate to the method of the twenty-sixth aspect in which the second concentration of carbon dioxide is 10 ppm or less.

[0031] In a twenty-eighth aspect, embodiments of the present disclosure relate to the method of the twenty-fifth aspect in which the gas stream is an industrial exhaust and the first concentration of carbon dioxide is 30 wt% to 40 wt%.

[0032] In a twenty-ninth aspect, embodiments of the present disclosure relate to the method of the twenty-eighth aspect in which the second concentration of carbon dioxide is 5 wt% or less.

[0033] In a thirtieth aspect, embodiments of the present disclosure relate to the method according to any of the twenty-fifth aspect through the twenty-ninth in which the method further comprises flowing steam through the media to cause the carbon dioxide to desorb from the media and storing the desorbed carbon dioxide in a manner that does not release the carbon dioxide to the environment.

[0034] Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0036] FIG. 1 depicts an exterior view of a carbon capture system, according to an exemplary embodiment;

[0037] FIG. 2 depicts an interior view of the carbon capture system of FIG. 1, according to an exemplary embodiment;

[0038] FIG. 3 depicts a carbon capture cell of a carbon capture system, according to an exemplary embodiment;

[0039] FIG. 4 depicts a carbon capture element of a carbon capture cell, according to an exemplary embodiment;

[0040] FIGS. 5 and 6 depict partial cross-sectional views of two carbon capture element constructions, according to exemplary embodiments;

[0041] FIGS. 7 and 8 depict partial cross-sectional, perspective views of two corrugated carbon capture media, according to exemplary embodiments;

[0042] FIGS. 9 and 10 schematically depict additional corrugation types of the carbon capture media, according to exemplary embodiments;

[0043] FIG. 11 schematically depicts a carbon capture media including fine fiber strands formed of a carbon capture material, according to an exemplary embodiment;

[0044] FIG. 12 depicts a manufacturing line for preparing fine fiber strands of the carbon capture media using Forcespinning®, according to an exemplary embodiment; and

[0045] FIG. 13 depicts a Forcespinning® chamber for preparing the fine fiber strands of the carbon capture media, according to an exemplary’ embodiment.

[0046] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.DETAILED DESCRIPTION OF THE INVENTION

[0047] Embodiments of the present disclosure relate to a carbon capture media that includes fine fibers, in particular nanofibers, formed from a carbon capture material. Conventional carbon capture media is provided in the form of carbon capture resin beads or a non-carbon capture fiber media that is functionalized with carbon capture material, such as in Chinese Publication Nos. CN106268636A, CN114192174A, and CN106975465A and International Publication Nos. W02011 / 035195A1, WO2012 / 168346A1. andW02023001810A1, the entire teachings of each of the foregoing references are incorporated herein by reference thereto. However, both of these types of media present issues with available surface area for capturing carbon dioxide. That is, capturing carbon dioxide is a surface process in which the carbon dioxide molecules are absorbed in or adsorbed on the surface of a carbon capture material. Thus, within a given volume, increasing the surface area of carbon capture material will lead to capturing of more carbon from a gas stream.

[0048] According to the present disclosure, the carbon capture media is formed from materials that themselves capture carbon. Specifically, the carbon capture media is formed from a fiber matrix that includes fine fiber strands of a carbon capture material, such as polymers with amine functional groups. The fiber matrix further includes nodules of the same or another material that captures carbon dioxide. Incorporation of such carbon capture media into elements of a carbon capture system will improve the efficiency of the system in removing carbon dioxide from the ambient environment or industrial exhaust gas stream. These and other aspects and advantages will be described more fully in relation to the embodiments presented below and shown in the figures. These embodiments are provided by way of illustration and not limitation.

[0049] FIG. 1 illustrates an embodiment of a carbon capture system 100, which is, in particular, a direct air capture system. The carbon capture system 100 includes an outer housing structure 102 with one or more inlet openings 104 through a side of the housing structure 102. such as the roof 106. Further, the carbon capture system 100 includes one or more outlet openings 108. In the embodiments depicted in FIG. 1, the outlet openings 108 are louvres 110 formed in walls 111 of the housing structure 102. A fan 112 positioned in each of the one or more inlet openings 104 directs a gas stream, in particular air from the surrounding environment, through the one or more inlet openings 104 into the outer housing structure 102. and as will be discussed more fully below, carbon dioxide is captured from the air within the outer housing structure 102 and output through the outlet openings 108. In this way, the concentration of carbon dioxide in the gas stream (environmental air) exiting the carbon capture system 100 is less than the concentration of carbon dioxide in the gas stream entering the carbon capture system 100.

[0050] FIG. 2 provides a perspective view of the internal structure of the carbon capture system 100 within the outer housing structure 102. Disposed within the outer housing structure 102 is a frame 200 holding a platform 202. Disposed on the platform 202 is a rotating carrier structure 204 having a first (upper) plate 206 and a second (lower) plate (not shown). Disposed between the first plate 206 and second plate are a plurality of carbon capture cells 210. The first plate 206 and the second plate are divided into sections 212, and in the embodiment show in FIG. 2, there are six sections 212a-212f. Further, in the embodiment shown, each section 212a-212f includes three carbon capture cells 210. Therotating carrier structure 204 rotates about an armature 214 extending on central axis 216. During operation, the fan 1 12 draws air into the direct air carbon capture system 100, forcing it through the carbon capture cells 210 of the rotating carrier structure 204. In particular, the platform 202 and rotating carrier structure 204 are sealed to each other and to the outer housing structure 102 in such a way that the air entering the carbon capture system 100 must flow through the carbon capture cells 210 to exit the carbon capture system 100. In the carbon capture cells 210, a plurality of carbon capture elements, which will be described in more detail below, absorb or adsorb the carbon dioxide from the gas stream, removing it from the gas stream.

[0051] During operation, the sections 212a-212f of the rotating carrier structure 204 pass between an upper arm 218 and a lower arm 220. The upper arm 218 and lower arm 220 each include a plurality of lids 222 corresponding to the number of carbon capture cells 210 of each section 212a-212f of the rotating carrier structure 204. The lids 222 are lowered to seal the carbon capture cells 210 against the flow of air through the carbon capture cells 210. Further, each lid 222 of the upper arm 218 and the lower arm 220 is connected to a steam conduit 224. As shown in FIG. 2, the upper arm 218 includes an inlet steam conduit 224a connected to its lid or lids 222, and the low er arm 220 includes an outlet steam conduit 224b connected to its lid or lids (not shown). Steam flows through the inlet steam conduit 224a into the carbon capture cells 210 to release the captured carbon dioxide from the carbon capture cells 210 and out of the carbon capture cells 210 into the outlet steam conduit 224b. The released carbon dioxide is carried by the outlet steam conduit 224b downstream for further processing in which the carbon dioxide and steam are separated and the carbon dioxide is stored without being released back into the atmosphere. Thus, as the carbon capture cells 210 reach their carbon capture capacity, the carbon capture cells 210 are exposed to steam to remove the captured carbon dioxide so that the carbon capture cells 210 can continue to capture additional carbon dioxide from the gas stream.

[0052] This example of a carbon capture system 100 is merely exemplary. Additional description of a carbon capture system 100 of this type can be found in International Publication No. WO2024 / 088859A1, ’‘System for Direct Air Capture of Carbon Dioxide,” published on May 2, 2024, the entire contents of w hich are incorporated herein by reference thereto. Other types of carbon capture systems 100 are compatible with the presentdisclosure. Further, as mentioned above, the present disclosure is also directed to point source carbon capture in which a gas stream resulting from an industrial process is directed through carbon capture cells 210. In such an embodiment, the one or more inlet openings 104 may be in fluid communication with a stack or other exhaust structure of an industrial process, such as power production, refining, or production of such products as steel, ammonia, or cement, amongst other possibilities. In general, the concentration of carbon dioxide in the gas stream entering the carbon capture system 100 is significantly higher (e.g., 30-40 wt%) for point source carbon capture systems than for direct air capture systems, but the principles of operation are generally the same.

[0053] FIG. 3 depicts an example of a carbon capture cell 210 that may be utilized in the carbon capture system 100 (either direct air or point source). As can be seen in FIG. 3, the carbon capture cell 210 includes a cell plate 300 having an upper surface 302 and a lower surface 304. A plurality of apertures 306 extend from the upper surface 302 to the lower surface 304. In one or more embodiments, each aperture 306 has an associated support structure 308 extending therefrom. In one or more such embodiments, the support structure 308 may be welded to the lower surface 304 of the cell plate 300. In this way, each support structure 308 may cany' a carbon capture element 400 as shown in FIG. 4.

[0054] Referring to FIG. 4. the carbon capture element 400 in one or more embodiments is a tubular structure comprised of a carbon capture media 402. The carbon capture media 402 can be any of a variety of structures that will be discussed in more detail below. Additionally, the carbon capture media 402 includes a first end cap 404, which may be a mounting cap for attachment of the carbon capture element 400 to the carbon capture cell 210. In the embodiment depicted, the first end cap 404 is disposed at a first end of the carbon capture element 400, but in other embodiments, the first end cap 404 may be disposed anywhere along the length of the carbon capture element 400 (e.g., depending on how the carbon capture element 400 is mounted to cell plate 300). In one or more embodiments, the carbon capture element 400 optionally includes a second end cap 406, which in the embodiment depicted is disposed at a second end of the carbon capture element 400.

[0055] In one or more embodiments, the first end cap 404 is an elastomeric end cap, such as EPDM rubber, that frictionally engages the support structure 308 of the cell plate 300 tohold the carbon capture element 400 in place on the support structure 308. In one or more embodiments, the second end cap 406 is a metallic end cap, such as stainless steel, configured to support the carbon capture element 400. In operation, the gas stream enters the apertures 306 of the cell plate and flows through the support structure 308 and carbon capture media 402 of the carbon capture element 400, the carbon dioxide in the gas stream being absorbed or adsorbed in the carbon capture media 402. Additionally, the carbon capture element 400 optionally includes a plurality of retaining straps or rings 408 configured to maintain the tubular shape of the filter media 402 along its length.

[0056] In one or more embodiments, the carbon capture element 400 has a length L in a range from 3 feet to 6 feet, in particular from 4 feet to 5 feet. In one or more embodiments, the outer diameter OD of the carbon capture element 400 is in a range from 2 inches to 12 inches, in particular from 4 inches to 5 inches.

[0057] In one or more embodiments, the carbon capture element 400 is configured to allow for an air flow velocity of at least 0.5 m / s, in particular, at least 3 m / s, and most particularly at least 6 m / s. In one or more embodiments, the carbon capture element 400 is configured to allow for a volumetric flow rate of at least 5 m3 / s, in particular at least 30 m3 / s, and most particularly at least 45 m3 / s. Further, in one or more embodiments, the carbon capture element 400 is configured to operate in an ambient temperature range of -22 °F to 140 °F in coastal, desert, industrial, or arctic environments, in particular while operating at 24 hours a day for at least 2 years.

[0058] FIGS. 5 and 6 provide partial cross-sectional views of the carbon capture element 400. Referring first to the embodiment depicted in FIG. 5, the carbon capture media 402 is a layered structure in which a sheet of carbon capture media 402 is wound into a tube shape. The first end cap 404 includes a channel 410 into which the carbon capture media 402 is inserted. A potting resin 411 disposed within the channel 410 attaches the carbon capture media 402 to the first end cap 404. Additionally, the tubular structure of the carbon capture media 402 is supported by a perforated core 412. The perforated core 412 provides mechanical support for the carbon capture media 402 while also allowing for the flow of the gas stream from the interior of the carbon capture element 400 through the carbon capture media 402.

[0059] In one or more embodiments, the perforated core 412 is formed from a metah such as stainless steel. In one or more embodiments, an inner diameter ID of the carbon capture element 400 is in a range from 1 inch to 4 inches, in particular in a range from 2 inches to 3 inches.

[0060] The embodiment shown in FIG. 6 is substantially the same as the embodiment show in FIG. 5 with the exception that the carbon capture media 402 is not supported with a perforated core 412 but is instead supported with a cage structure 414. In one or more embodiments, the cage structure 414 is formed form a polymer material, such as polypropylene. Despite the difference in material and structure, the purpose of the cage structure 414 is substantially the same as the perforated core 412, namely to support the carbon capture media 402 while allowing for air flow from the interior of the carbon capture element 400 through the carbon capture media 402.

[0061] FIGS. 7 and 8 provide two additional types of carbon capture media 402 construction. FIG. 7 depicts a corrugated media 500 including a plurality of longitudinal channels 502. One end of the longitudinal channels 502 is plugged with resin such that a gas stream flowing into an open end 504 of the corrugated media 500 is directed into the longitudinal channels 502 and is forced to flow through the carbon capture media 402 to exit the longitudinal channels 502. In one or more embodiments, the corrugated media 500 is comprised of a corrugated sheet 506 and a flat sheet 508 that are rolled together around a core 510. FIG. 8 depicts another type of corrugated media 500 in which alternating longitudinal channels 502 are blocked with resin 512. Thus, about half the longitudinal channels 502 at each end are blocked with resin 512. In this way, a gas stream entering the first end 514 of the corrugated media 500 flows axially along the length of the longitudinal channel 502 and must pass through the carbon capture media 402 in order to flow axially out the other end.

[0062] In the embodiments show in FIGS. 7 and 8, the corrugations are substantially triangular in shape, but in one or more other embodiments, the corrugations may be other shapes, such as arcs (as shown in FIG. 9), rectangles, or squares (as shown in FIG. 10). Additionally, in one or more embodiments, the carbon capture media 402 may be provided as a loose batting stuffed within a support structure of the carbon capture element 400.

[0063] Having described examples of a carbon capture system and carbon capture element, the following discussion will be directed to the particular carbon capture media that allows for removal of carbon dioxide from a gas stream. According to the present disclosure, the carbon capture media 402 includes fine fiber strands, in particular nanofiber strands, that are formed form a material configured to absorb or adsorb carbon dioxide.

[0064] Additionally, the fine fiber strands are provided with nodules formed of a material that is also configured to absorb or adsorb carbon dioxide. By using fine fiber strands of a carbon capture material, the carbon capture media 402 is able to provide enhanced surface area for capturing carbon dioxide. That is, the carbon capture media 402 dedicates much more of the volume within the envelope of the carbon capture element 400 to the purpose of capture carbon dioxide, which increases the amount of carbon dioxide that can be captured and decreases the number of desorption cycles. In this way, a system incorporating a carbon capture element 400 with a carbon capture media 402 according to the present disclosure is able to operate more efficiently than conventional carbon capture systems that utilize, e.g., resin beads for carbon capture.

[0065] FIG. 11 depicts an example of a carbon capture media 402 for capturing carbon dioxide from a gas stream. In one or more embodiments, the gas stream is ambient air. In such embodiments, the concentration of carbon dioxide in the air may be in a range of about 300 ppm to 500 ppm. Further, in one or more such embodiments, the concentration of carbon dioxide in the ambient air that has flowed through the media is 10 ppm or less, in particular 0 ppm.

[0066] In one or more embodiments, the gas stream is exhaust from an industrial process in which the concentration of carbon dioxide in the gas stream may be up to 30 wt%, or even up to 40 wt%. In such embodiments, the concentration of carbon dioxide in the gas stream that has flowed through the media is 5 wt% or less, in particular 0 wt%.

[0067] FIG. 11 is a schematic representation of the carbon capture media 600 according to an example embodiment. The media 600 is comprised of a fiber matrix 602 including fine fiber strands 604. The fine fiber strands 604 are formed from at least one first polymer capable of capturing carbon dioxide through absorbance or adsorbance. In one or moreembodiments, the fine fiber strands 604 have a mean fiber diameter of 5000 nm or less, in particular 2500 nm or less, particularly 1000 nm or less, and most particularly 500 nm or less. In embodiments in which the fine fiber strands have a mean fiber diameter of 1000 nm or less, the fine fiber strands may also be referred to as nanofiber strands. In one or more embodiments, the mean fiber diameter is determined by measuring a width of a plurality of fine fiber strands 604 in a plurality of SEM images of a batch of fine fiber strands 604. Such measurements may be performed using image analysis software known in the art.

[0068] In one or more embodiments, the fine fiber strands 604 have a mean fiber diameter of 10 nm or greater, in particular 100 nm or greater. For example, in one or more embodiments, the fine fiber strands 604 may have an average diameter in a range from 10 nm to 800 nm, in particular! 00 nm to 500 nm. In one or more embodiments, the at least one first polymer of the fine fiber strands 604 comprises an amine functional group. In one or more specific embodiments, the at least one first polymer of the fine fiber strands 604 is selected from a group consisting of polyethyleneimine, ethylenediamine, tetra-ethylenepentamine, diethanolamine, diethylenetriamine, tris(2-aminoethyl)amine, penta-ethylenehexamine, and combinations thereof.

[0069] In one or more embodiments, the fine fiber strands 604 in the fiber matrix 602 are crosslinked. In such embodiments, the crosslinking may be achieved by chemical treatment at a temperature of 130 °C or less, in particular 100 °C or less, and most particularly at ambient room temperature. In one or more embodiments, the fine fiber strands 604 are chemically crosslinked using, e.g., one or more of an epoxy resin, suberic acid, glutaric acid, a peroxide, an isocyanate, glutaraldehyde, among other possibilities known in the art.

[0070] Further, as shown in FIG. 11 , the media 600 further includes a plurality of nodules 606 dispersed in the fiber matrix 602. The plurality of nodules 606 are formed from a nodule material capable of capturing carbon dioxide through absorbance or adsorbance.

[0071] In one or more embodiments, the plurality of nodules 606 are formed from the at least one first polymer that forms the fine fiber strands 604. As will be discussed more fully below, the manner in which fine fiber strands 604 are formed causes formation of the plurality of nodules 606 from the same material as the fine fiber strands 604. In such an embodiment.the nodules 606 are droplets of the at least one first polymer material connected to the fine fiber strands 604.

[0072] In one or more embodiments, the plurality of nodules 606 are formed from a nodule material that is selected from a group consisting of an amine-loaded sorbent, graphene, carbon nanotubes, activated carbon, honeycomb monolith, a hybrid crystalline material, a zeolite, a silica, a silica-alumina. and combinations thereof.

[0073] In one or more embodiments, the plurality of nodules 606 comprise an average diameter in a range of 250 nm to 20 pm, in particular 1 pm to 10 pm.

[0074] In one or more embodiments, the fiber matrix 602 includes second fiber strands 608 that have a diameter greater than the diameter of the fine fiber strands 604. In such embodiments, the second fiber strands 608 may be included to provide mechanical support for the fine fiber strands 604.

[0075] In one or more embodiments, the second fiber strands 608 are formed from at least one second polymer selected from a group consisting of a polyamide, a polyacrylonitrile, a cellulosic material, a polyvinyl alcohol, a polyvinyl chloride, a polyvinylpyrrolidone, a chitosan, a polytynethyl methacrylate), a polyacrylamide, and combinations thereof.

[0076] In one or more embodiments, the second fiber strands 608 have an average diameter in a range from 1 pm to 25 pm. in particular in a range from 2.5 pm to 15 pm.

[0077] In one or more embodiments, a ratio of the second fiber strands 608 to the fine fiber strands 604 is 1 : 1 to 1 :300. in particular 1 : 1 to 1:50.

[0078] In one or more embodiments, the media 600 comprising the fiber matrix 602, including the fine fiber strands 604 and second fiber strands 608 (if provided), and plurality of nodules 606 is further supported by a scrim, such as a non-woven scrim. In such embodiments, the non-woven scrim is formed from a third polymer selected from a group consisting of a polypropylene, a polyethylene, a polyacrylonitrile, a polyamide, a polyvinylchloride, and combinations thereof. In one or more embodiments, the fiber matrix 602 is joined to the scrim by thermal lamination, adhesion, or fiber entanglement.

[0079] FIG. 12 depicts an exemplary embodiment of a manufacturing line 700 for creating the fine fiber strands 604. The fine fiber strands 604 are deposited as a loose batt 702 in a fiber deposition chamber 704. The fine fiber strands 604 are preferably produced via centrifugal spinning (herein referred to as "Forcespinning®") and deposited on a moving substrate 706. The moving substrate 706 can be incorporated into the loose batt 702 of fine fiber strands 604, such as with a bed of the second fiber strands and / or a scrim material, or the moving substrate can be separate from the loose batt 702 of fine fiber strands 604. such as a conveyor system 708 (as depicted in FIG. 12).

[0080] FIG. 13 depicts a more detailed schematic view of a section of the fiber deposition chamber 704. As depicted in FIGS. 12 and 13, the deposition chamber 704 is a Forcespinning® chamber. Forcespinning® involves centrifugally expelling a liquid polymer (i.e., at least one of a polymer melt or polymer solution) through orifices in at least one spinneret 710 while rotating the spinneret 710 at a speed of at least 2500 rpms. This centrifugal action results in the drawing down of the mean fiber diameter of the fine fiber strands 604 to 5000 nm or less, particularly in a range of 10 nm to 800 nm. It should be noted that the Forcespinning® process does not use electrospinning forces to draw down the diameter of the fine fiber strands 604.

[0081] The deposition chamber 704 of FIG. 13 depicts a single spinneret 710, but more spinnerets 710 can be included in the deposition chamber 704, such as shown in FIG. 12, depending on the amount of fine fiber strands 604 needed. The spinnerets 710 typically are capable of moving in the X, Y, and Z planes to provide a range of coverage options for producing the loose batt 702. Each spinneret 710 features a plurality of orifices 712 through which the fine fiber strands 604 are expelled. The orifices 712 can each be connected to the same reservoir of polymer melt, polymer solution, or liquid adhesive, or each orifice 712 can be connected to a different reservoir of polymer melt, polymer solution, or liquid adhesive. Moreover, in embodiments with multiple spinnerets 710, each spinneret 710 can expel a different polymer melt, polymer solution, or liquid adhesive. During deposition of the finefiber strands 604, the spinnerets 710 will rotate at least at 2500 rpms. More typically, the spinnerets 710 will rotate at least at 5000 rpms.

[0082] Using the spinnerets 710, the fine fiber strands 604 can be created using, for example, a solution spinning method or a melt spinning method. A polymer melt can be formed, for example, by melting a polymer or a polymer solution may be formed by dissolving a polymer in a solvent. Polymer melts and / or polymer solutions as used herein also refers to the material formed from heating the polymer to a temperature below the melting point and then dissolving the polymer in a solvent, i.e., creating a “polymer melt solution.’' The polymer solution may further be designed to achieve a desired viscosity, or a surfactant may be added to improve flow, or a plasticizer may be added to soften a rigid fiber, or an ionic conductor may be added to improve conductivity. The polymer melt can additionally contain polymer additives, such as antioxidant, colorants, or cross-linking agents.

[0083] Additionally, in one or more embodiments, the particles or materials of the plurality’ of nodules 606 added to the polymer solution prior to spinning the fine fiber strands 604. In this way. the fine fiber strands 604 will become bonded to the nodules 606 during the spinning process. Thus, when the fiber matrix 602 is created from the fine fiber strands 604, the fiber matrix 602 will already include the nodules 606 without requiring separate processing.

[0084] Several optional features of the deposition chamber 704 are depicted in FIG. 13. Generally, the fine fiber strands 604 are preferably continuous fibers (though the fine fiber strands 604 are depicted schematically as short fibers in FIG. 13). The fine fiber strands 604 can be encouraged downwardly to collect on the moving substrate 706 through a variety’ of mechanisms that can work independently or in conjunction with each other. For example, in some embodiments, a gas flow system 714 can be provided to induce a downward gas flow, depicted with arrows 716. The gas flow system 714 can also include lateral gas flow jets 718 that can be controlled to direct gas flow in different directions within the deposition chamber 704. Additionally, in some embodiments, formation of the fine fiber strands 604 will induce an electrostatic charge, either positive or negative, in the fiber. This electrostatic charge is not used to draw the fiber to the desired thickness such as in electrospinning. Nevertheless, an electrostatic plate 720 can be used to attract the charged fine fiber strands 604 downwardlyto the moving substrate 706. Thus, as can be seen in FIG. 13, the electrostatic plate 720 is located below the moving substrate 706. Furthermore, in some embodiments, a vacuum system 722 is provided at the bottom of the deposition chamber 704 to further encourage the fine fiber strands 604 to collect on the moving substrate 706. Still further, in some embodiments, an outlet fan 724 is provided to evacuate any gasses that may develop, such as might develop as the result of solvent evaporation or material gasification, during the Forcespinning® process.

[0085] Notwithstanding the foregoing, in other embodiments, the fine fiber strands 604 can be created using a different method than Forcespinning® or in conjunction with Forcespinning®. For example, in one embodiment, the fine fiber 10 can be produced via electrospinning or melt blowing. However, where the polymer of the fine fiber strands 604 contains an amine group, preferably the temperature of the process is kept below 120 °C.

[0086] In one or more embodiments, the fine fiber strands 604 are chemically treated during spinning or after spinning in order to promote crosslinking as discussed above.

[0087] In one or more embodiments, the fine fiber strands 604 that are incorporated into the loose batt 702 have a length greater than 1 millimeter, in particular greater than 10 cm, and most particularly greater than 1 meter (i.e., continuous strands).

[0088] Returning to FIG. 12, the loose batt 702 of fine fiber strands 604 is transported out of the deposition chamber 704 on the moving substrate 706. The Forcespinning® process may produce enough fiber entanglement by itself that further entanglement is unnecessary. However, as depicted in FIG. 12, the loose batt 702 is transported to a needlepunching machine 726 to increase the amount of entanglement of the fine fiber strands 604, including with the second strands 608 (if provided). If a scrim or porous substrate is utilized, the needlepunching machine 726 can punch the fine fiber strands 604 into the scrim or porous substrate. Other methods of fiber entanglement can also be utilized as necessary’, such as hydro-entanglement. Once the fibers are sufficiently entangled, either through Forcespinning® alone or through another entanglement process, the fine fiber strands 604 form the fiber matrix 602.

[0089] If the nodules 606 were not included in the Forcespinning® process, the nodules can be added to the fiber matrix 602 after the fiber matrix 602 is formed. In one or more embodiments, the nodules 606 are attached to the fiber matrix 602 using adhesives or other bonding agents. For example, in one or more embodiments, the adhesive is a moisture-cured hot melt adhesive, and the fiber matrix 602 is exposed to steam in order to activate the adhesive and bond the nodules 606 to the fiber matrix. In one or more embodiments in which the fine fiber strands 604 are formed through solvent-spinning, the nodules 606 may be bonded to the fiber matrix 602 during solvent evaporation, which renders the fine fiber strands 604 tacky so that the nodules 606 can stick to the fiber matrix 602. In one or more embodiments, the nodules 606 are added between layers of fiber matrix 602. and the layers of fiber matrix 602 are laminated together around the nodules 606. In the foregoing embodiments of attaching the nodules 606 to the fiber matrix 602, the bonding can be further controlled by using downstream temperature-controlled calendaring.

[0090] Optionally, the fiber matrix 602 can be further processed to enhance the bonding of the fibers or to increase the density of the media. As depicted in FIG. 12, the fiber matrix 602 travels through calendaring rolls 728. Multiple sets of calendaring rolls can be utilized, and the calendaring rolls can be heated. As mentioned, the calendaring rolls 728 can be utilized to enhance the bonding of the nodules 606 to the fiber matrix 602. Also, as depicted in FIG. 12, the fiber matrix 602 travels through an oven 730, which can soften the fine fiber strands 604 such that the fine fiber strands 604 thermally bond to each other. At the end of the manufacturing line 700, the fiber matrix 702 is taken up in a roll 732 for storage or transportation for further processing, such as winding into a tubular structure, corrugation, etc.

[0091] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety7herein.

[0092] The use of the terms "a” and "an" and "the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising / 7“having,” “including / ’ and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0093] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

WHAT IS CLAIMED IS:

1. A media for capturing carbon dioxide from a gas stream of ambient air or industrial exhaust, the media comprising: a fiber matrix comprising fine fiber strands formed from at least one first polymer capable of capturing carbon dioxide through absorbance or adsorbance, the fine fiber strands having a first mean diameter of 5000 nm or less; and a plurality of nodules dispersed in the fiber matrix, the plurality of nodules comprising a nodule material capable of capturing carbon dioxide through absorbance or adsorbance.

2. The media of claim 1, wherein the first mean diameter of the fine fiber strands is 2500 nm or less.

3. The media of claim 1 or claim 2, wherein the first mean diameter of the fine fiber strands is 1000 nm or less.

4. The media of any of claims 1-3, wherein the fine fiber strands are crosslinked.

5. The media of any of claims 1-4, wherein the at least one first polymer is selected from a group consisting of polyethyleneimine, ethylenediamine, tetra-ethylenepentamine, diethanolamine, diethylenetriamine, tris(2-aminoethyl)amine, penta-ethylenehexamine, and combinations thereof.

6. The media of any of claims 1-5, wherein the fiber matrix further comprises second fiber strands of at least one second polymer configured to provide mechanical support for the fine fiber strands, the second fiber strands having a second mean diameter that is greater than the first mean diameter.

7. The media of claim 6, wherein the second mean diameter of the second fiber strands is in a range from 1 gm to 25 gm.

8. The media of claim 6 or claim 7, wherein the second mean diameter of the second fiber strands is in a range from 2.5 gm to 15 gm.

9. The media of any of claims 6-8, wherein the at least one second polymer is selected from a group consisting of a polyamide, a polyacrylonitrile, a cellulosic material, a polyvinyl alcohol, a polyvinyl chloride, a polyvinylpyrrolidone, a chitosan, a poly(methyl methacrylate), a poly acry lamide, and combinations thereof.

10. The media of any of claims 1-9, wherein the nodule material is selected from a group consisting of an amine-loaded sorbent, graphene, carbon nanotubes, activated carbon, honeycomb monolith, a hybrid crystalline material, a zeolite, a silica, a silica-alumina, and combinations thereof.

11. The media of any of claims 1-10. wherein the plurality of nodules comprises a mean diameter in a range of 250 nm to 20 pm.

12. The media of any of claims 1-11. wherein the plurality of nodules comprises a mean diameter in a range of 1 gm to 10 gm.

13. The media of any of claims 1-12. further comprising a non-woven scrim.

14. The media of claim 13, wherein the non-woven scrim is formed from a third polymer selected from a group consisting of a polypropylene, a polyethylene, a polyacrylonitrile, a polyamide, a polyvinyl chloride, and combinations thereof.

15. The media of any of claims 1-14. wherein the first polymer comprises a polymer with an amine functional group.

16. The media of any of claims 1-15. wherein the nodule material comprises a polymer with an amine functional group.

17. A carbon capture element, comprising the media according to any of claims 1-16.

18. The carbon capture element of claim 17, wherein the media is wound in layers to form a tubular structure.

19. The carbon capture element of claim 17, wherein a first sheet of the media is corrugated and a second sheet of the media is flat, wherein the first sheet and the second sheet are wound around a central core in layers to form a plurality of longitudinal channels.

20. The carbon capture element of claim 19, wherein about half of the longitudinal channels are plugged with resin at a first end and the remaining longitudinal channels are plugged with resin at a second end opposite the first end.

21. The carbon capture element of claim 17. comprising: a core; the media wound in layers around the core; and a first end cap; wherein the media and the core are potted into the first end cap at a first end of the carbon capture element.

22. The carbon capture element of claim 21, wherein the core is a perforated metal core or a polymeric cage.

23. The carbon capture element of claim 21 or claim 22. further comprising a second end cap, wherein the media and the core are potted into the second end cap at a second end of the carbon capture element opposite to the first end.

24. A carbon capture cell, comprising: a cell plate comprising a first surface and a second surface, the second surface being opposite to the first surface; a pl ural ity of apertures formed through the cell plate from the first surface to the second surface; a plurality of support structures, each support structure of the plurality’ of support structures extending form the second surface of the cell plate around each aperture of the plurality of apertures; a plurality of carbon capture elements according to any of claims 17-23, each carbon capture element of the plurality of carbon capture elements being disposed on a support structure of the plurality of support structures.

25. A method of reducing a concentration of carbon dioxide in a gas stream, comprising: flowing the gas stream having a first concentration of carbon dioxide through the media of any of claims 1-16 from a first side to a second side; and adsorbing or absorbing the carbon dioxide in the media such that a second concentration of the carbon dioxide on the second side of the media is less than the first concentration of carbon dioxide on the first side of the media.

26. The method of claim 25, wherein the gas stream is ambient air and the first concentration of carbon dioxide is in a range of 300 ppm to 500 ppm.

27. The method of claim 26, wherein the second concentration of carbon dioxide is 10 ppm or less.

28. The method of claim 25, wherein the gas stream is an industrial exhaust and the first concentration of carbon dioxide is 30 wt% to 40 wt%.

29. The method of claim 28, wherein the second concentration of carbon dioxide is 5 wt% or less.

30. The method of any of claims 25-29, further comprising flowing steam through the media to cause the carbon dioxide to desorb from the media and storing the desorbed carbon dioxide in a manner that does not release the carbon dioxide to the environment.

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