WO2023212547A1

WO2023212547A1 - Phenyl containing sorbents, bicarbonate containing sorbents, systems including sorbents, and methods using the sorbents

Info

Publication number: WO2023212547A1
Application number: PCT/US2023/066169
Authority: WO
Inventors: Miles SAKWA-NOVAK; Eric PING; Joan LUCAS; Abigayle CLABAUGH; Cassandra HERTZ; Yanhui Yuan; Stephanie DIDAS
Original assignee: Global Thermostat Operations, Llc.
Priority date: 2022-04-25
Filing date: 2023-04-25
Publication date: 2023-11-02

Abstract

The present disclosure is directed to multiple types of sorbents and structures. The present disclosure provides for phenyl amine containing, bicarbonate salt containing, or phenyl amine and bicarbonate salt containing sorbents and contactors, methods of using sorbents and contactors to capture CO2, structures including the sorbent, and systems and devices using sorbents and contactors to capture CO2.

Description

PHENYL CONTAINING SORBENTS, BICARBONATE CONTAINING SORBENTS, SYSTEMS INCLUDING SORBENTS, AND METHODS USING THE SORBENTS

CLAIM OF PRIORITY TO RELATED APPLICATION

This application claims priority to co-pending U.S. provisional application entitled “SORBENTS, SYSTEMS INCLUDING SORBENTS, AND METHODS USING THE SORBENTS” having Serial No.: 63/363,507 filed on April 25, 2022, which is entirely incorporated herein by reference.

BACKGROUND

Greenhouse gases trap heat in the atmosphere and carbon dioxide (CO2) is one of the main greenhouse gases. CO2 is emitted through human related activities such as transportation, electric power, industry and agriculture. In particular, CO2 emissions are caused by burning fossil fuels, solid waste, and trees as well as through the manufacture of cement and other materials. One way to decrease the amount of CO2 in the atmosphere is to capture CO2 using materials having an affinity for CO2. There is a need for materials that can effectively capture CO2.

SUMMARY

Embodiments of the present disclosure provide for phenyl amine containing sorbents, bicarbonate salt containing sorbents, or phenyl amine and bicarbonate salt containing sorbents and contactors, methods of using sorbents and contactors to capture CO2, structures including the sorbent, and systems and devices using the sorbents and contactors to capture CO₂.

Embodiments of the present disclosure provide for a sorbent comprising: a CO₂-philic phase and a support, wherein the CC>2-philic phase includes CO2 binding molecules moieties and phenyl amine containing molecules, wherein the CO2 binding molecules include CO2 binding moieties.

Embodiments of the present disclosure provide for a sorbent comprising: a CO2-philic phase and a support, wherein the CC>2-philic phase includes CO2 binding molecules moieties and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties.

Embodiments of the present disclosure provide for a sorbent comprising: a CC>2-philic phase and a support, wherein the CCh-philic phase includes CO2 binding molecules moieties and both phenyl amine containing molecules and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties. Embodiments of the present disclosure provide for a contactor, comprising a structure and the sorbent as described herein or above. The structure can be selected from a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, or a combination of these.

Embodiments of the present disclosure provide a system for capturing CO2 from a gas, optionally the gas is ambient air, comprising: a first device configured to introduce the gas to the sorbent or contactor as described above or herein to bind CO2 to the sorbent; a second device configured to heat the sorbent containing bound CO2 to at least a first temperature to release the CO2; and a third device configured to collect the released CO2. After being heated the sorbent can be regenerated so it able to absorb CO2 from the gas. The sorbent can be in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof. The honeycomb has an open face area of between 0.3-0.95. The gas approaches the honeycomb at a velocity of between 0.25-10 m/s. The system is configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO2.

Embodiments of the present disclosure provide for a method of capturing CO2 from gas optionally the gas is ambient air comprising: introducing the ambient air to the sorbent of as described above or herein to bind CO2 to the sorbent; heating the sorbent to at least a first temperature to controllably release the CO2; and collecting the CO2 in a CO2 collection device. Heating the sorbent regenerates the sorbent so it is able to absorb CO2 from ambient air. The sorbent can be heated by contacting it with steam. The method can be configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO2. The sorbent can be in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof. The present disclosure provides for systems for implementing the method as described above or herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present disclosure will be more readily appreciated upon review of the detailed description of its various embodiments, described below, when taken in conjunction with the accompanying drawings.

Figure 1A shows a schematic of how amine moieties bind CO2 into the form of a carbamate. Figure 1 B is a schematic of a sorbent system comprised of support and CC>2-philic phase. Together, the support and CC>2-philic phase comprise a sorbent. Figure 2 is a schematic of honeycomb monolith contactor comprised of a substrate and a sorbent washcoat.

Figure 3 illustrates a schematic showing additive molecules evaluated, categorized by the type of molecule.

Figure 4 illustrates FTIR spectra of sorbents created with improved CC philic phases comprised of PEI and Amine 1 or Amine 6 supported on mesoporous alumina. The amines are present at a ratio of 0.1 mol/mol N in PEI.

Figure 5A and 5B illustrate pore size distributions (Figure 5A) and N₂ isotherms (Figure 5B) of mesoporous alumina support material, sorbent created with mesoporous alumina support and unmodified PEI, and sorbent created with mesoporous alumina support and PEI with 4,4’- Bis(a,a-dimethylbenzyl)diphenylamine at 0.1 mol/mol.

Figure 6 illustrates mass loss curves during exposure of sorbents created with improved COs-philic phases containing PEI and phenyl amine additives and unmodified PEI to diluted air while ramping the temperature from room temperature to 900° C. The amines are present at a ratio of 0.1 mol/mol N in PEI.

Figure 7 illustrates heat flow (DSC) curves during exposure of sorbents created with improved CC>2-philic phases containing PEI and phenyl amine additives and unmodified PEI to diluted air while ramping the temperature from room temperature to 900° C. The amines are present at a ratio of 0.1 mol/mol N in PEI.

Figure 8 illustrates mass loss curves during exposure of sorbents created with improved CC>2-philic phases containing PEI and bicarbonate salt additives and unmodified PEI to diluted air while ramping the temperature from room temperature to 900° C. The bicarbonates are present at a ratio of 0.1 mol/mol N in PEI.

Figure 9 illustrates heat flow (DSC) curves during exposure of sorbents created with improved CO₂-philic phases containing PEI and bicarbonate salt additives and unmodified PEI to diluted air while ramping the temperature from room temperature to 900° C. The bicarbonates are present at a ratio of 0.1 mol/mol N in PEI.

Figure 10 illustrates mass loss curve (dashed lines) and heat flow (DSC, solid lines) of sorbents created with different mesoporous supports and PEI with 4,4’-Bis(a,a- dimethylbenzyl)diphenylamine at 0.1 mol/mol during exposure to diluted air while ramping the temperature from room temperature to 900° C.

Figure 11 illustrates transient mass change profiles from TGA CO₂ uptake experiments at 400 ppm CO2 (DAC conditions) utilizing improved sorbents containing PEI and phenyl amine additives; each at 0.1 mol additive / mol PEI, and all supported in a mesoporous alumina. Data for a sorbent utilizing PEI is shown for reference as well. Data are reported as amine efficiency (mol CO2 / mol N in PEI present in sample).

Figure 12 illustrates transient mass change profiles from TGA CO2 uptake experiments at 400 ppm CO₂ (DAC conditions) utilizing improved sorbents containing PEI and bicarbonate salt additives and Amine 1 + Bicarbonate 1; each at 0.1 mol additive I mol PEI, and all supported in a mesoporous alumina. Data for a sorbent utilizing PEI is shown for reference as well. Data are reported as amine efficiency (mol CO21 mol N in PEI present in sample).

Figure 13 illustrates extent of oxidation over time of PEI, determined via the differential scanning calorimetry method described herein and discussed in the referenced publication (solid lines, DSC), and via the loss of amine efficiency (datapoints, AE) at (A) 5%, (B) 17%, and (C) 30% O₂ concentration; (D) extent of oxidation with different PEI pore fillings. Figure taken from Nezam et al, ACS Sustainable Chem. Eng., 2021 , 9, 8477-8486.

Figure 14 illustrates transient oxidation curves for PEI and PEI with phenyl amine additive tested under 20% CO2, 17% O2, balance N₂ at 125 °C, all sorbents are in a mesoporous alumina, additive ratios are 0.1 mol additive / mol PEI.

Figure 15 illustrates transient oxidation curves for PEI and PEI with phenyl amine additive tested under 17% O2, balance N2 at 137.5 °C, all sorbents are in a mesoporous alumina, additive ratios are 0.1 mol additive / mol PEI.

Figure 16 illustrates transient oxidation curves for PEI and PEI + Bicarbonate 1 tested under 20% CO2, 17% O2, balance N₂ at 125 °C, all sorbents are in a mesoporous alumina, additive ratios are 0.1 mol additive / mol PEI.

Figure 17 illustrates transient oxidation curves for PEI and PEI with bicarbonate salt additive tested under 17% O2, balance N₂ at 137.5 °C, all sorbents are in a mesoporous alumina, additive ratios are 0.1 mol additive / mol PEI.

Figure 18 illustrates transient oxidation curves for PEI, PEI + Amine 1 , PEI + Bicarbonate 1 , and PEI + Amine 1 + Bicarbonate 1 tested under 17% O2, balance N₂ at 137.5 °C, all sorbents are in a mesoporous alumina additive ratios are 0.1 mol additive / mol PEI.

Figure 19 illustrates transient oxidation curves for PEI, and PEI + Amine 1 at varied mol additive/ mol PEI ratios tested under 17% O2, balance N2 at 137.5 °C, all sorbents are in a mesoporous alumina.

Figure 20 illustrates transient oxidation curves for PEI (solid), and PEI + Amine 1 (dashed) in different mesoporous supports tested under 17% O2, balance N₂ at 137.5 °C, additive ratios are 0.1 mol additive / mol PEI. Figure 21 illustrates CO2 uptake curves for honeycomb monolith sorbents containing PEI and an improved CO₂-philic phase comprised of PEI and Amine 1 at a molar ratio of 0.1 mol additive / mol PEI. The curves are shown relative to the quantity of amine in PEI present, known as amine efficiency (mol CO₂ adsorbed / mol N in PEI present in sample). The data were collected using ambient air at an approach velocity of 5 m/s to the monolith face.

Figure 22 illustrates mass loss curve (dashed line) and heat flow (DSC, solid line) of honeycomb monoliths containing PEI + Amine 1 , PEI + Amine 6, and PEI + Amine 11 during exposure to diluted air while ramping the temperature to 900 °C.

DETAILED DISCLOSURE

Embodiments of the present disclosure provide for phenyl amine containing sorbents, bicarbonate salt containing sorbents, or phenyl amine and bicarbonate salt containing sorbents (“sorbents” are also referred to herein as “sorbent” or “sorbents”) and contactors, methods of using sorbents and contactors to capture CO2, structures including the sorbent, and systems and devices using the sorbents and contactors to capture CO2. The methods, systems, and sorbents of the present disclosure can be advantageous over current technologies since they are relatively more robust and reduce the cost of capturing CO₂, in particular from ambient air. In an aspect, the present disclosure provides for sorbents having a support and a CO₂-philic phase that includes phenyl amine containing molecules, bicarbonate salt containing molecules, or phenyl amine and bicarbonate salt containing molecules, which leads to a sorbent that is effective for capturing CO₂.

Before the present disclosure is described in greater detail, it is to be understood that this disclosure is not limited to particular embodiments described, and as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of chemistry, materials science, mechanical engineering, and the like, which are within the skill of the art.

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to perform the methods and use the probes disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by volume, temperature is in °C, and pressure is at or near atmospheric. Standard temperature and pressure are defined as 20 °C and 1 atmosphere.

Before the embodiments of the present disclosure are described in detail, it is to be understood that, unless otherwise indicated, the present disclosure is not limited to particular materials, reagents, reaction materials, manufacturing processes, or the like, as such can vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. It is also possible in the present disclosure that steps can be executed in different sequences where this is logically possible.

It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a compound” includes a plurality of compounds. In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings unless a contrary intention is apparent. Discussion

The present disclosure provides for phenyl amine containing sorbents, bicarbonate salt containing sorbents, or phenyl amine and bicarbonate salt containing sorbents (also referred to herein as “sorbent” or “sorbents”) and contactors, methods of using sorbents and contactors to capture CO2, structures including the sorbent, and systems and devices using sorbents and contactors to capture CO2. The present disclosure is directed to multiple types of sorbents and structures that will be described below and herein.

In an aspect, the present disclosure provides for sorbents and contactors that include a CC>2-philic phase and a support. The CC>2-philic phase includes CO2 binding molecules and phenyl amine containing molecules. The CC>2-philic phase can be a homogeneous mixture or a heterogeneous mixture. The CO2 binding molecules contain CO2 binding moieties. The ratio of the amount of phenyl amine containing molecules to CO2 binding moieties can be about 0.0001 to 1 mole phenyl amine containing molecule to mole CO2 binding moiety or about 0.01 to 0.5 mole phenyl amine containing molecule to mole CO2 binding moiety. When the CO2 binding molecules and phenyl amine containing molecules are mixed together, the phenyl amine containing molecules can act as a stabilizer for the CO2 binding molecules to improve its stability thereby creating an improved CC>2-philic phase. In an aspect, when the improved CO2- philic phase is incorporated into the pores of a porous support material, for example, an effective CO2 sorbent is formed. Further, the sorbents created with the improved CO₂-phil ic phase lose less of the capacity to capture CO2 following oxidative exposures compared to sorbents created without the improvement to the CC>2-philic phase, thereby providing them with longer commercial lifetime.

A structured support, also referred to as a formed support or as a structure, refers to a support that has been formed into a structure where the structure is, at standard conditions, a solid body. Supports can also be unstructured, at standard conditions having a powdery consistency. When a support is referred to without mention to a structure, forming, or being formed or structured, it can refer to supports that are either structured or unstructured.

Structured supports can take the form of a homogeneous solid body (i.e. , comprised predominantly of support but also containing components that allow it to remain a stable body at standard conditions) or as a coating on a substrate, whereby the substrate has a different composition than the coating and provides the mechanical stability to the coating.

It can be useful to utilize a structured support with a CC philic phase as a contactor in a process for removing CO2 from a gas stream such as ambient air. Contactors provide a geometry to a COs-philic phase such that considerations such as pressure drop, throughput, and/or mass transfer rates can be optimized.

The CO2 binding molecules can be an amine or an amine polymer. The amine or amine polymer can contain primary amines, secondary amines, tertiary amines, or a mixture of any combination of primary, secondary, and tertiary amines. The amine polymer can be branched, hyperbranched, dendritic, or linear. The CO2 binding moieties are the amine moieties on the amine molecule or polymer. The amine moieties can interact with CO2 to form carbamate, carbonate, or bicarbonate species. Figure 1 A shows a schematic of how amine moieties bind CO2 into the form of a carbamate.

Primary amines are defined as having the chemical structure -NH₂R¹, where R¹ is an alkyl group such as CH2 or CH3. Secondary amines are defined as having the chemical structure -NHR¹R², where R¹ and R² are independently selected from an alkyl group such as CH2 or CH3. Tertiary amines are defined as having the chemical structure -NR¹R²R³, where R¹, R², and R³ are independently selected from an alkyl group such as CH₂ or CH₃.

Linear amine polymers can be defined as containing only primary amines, secondary amines, or both primary and secondary amines. The ratio of secondary to primary amines can be about 0.5 to 10,000. In an aspect, the linear amine polymer can have a molecular weight of about 100 to 100,000 g/mol, about 200 to 30,000 g/mol or about 600 to 5,000 g/mol.

Branched amine polymers can be defined as containing any number of primary, secondary, and tertiary amines, which does not overlap linear amine polymers or dendritic amine polymers. The ratio of primary, secondary, and tertiary can be about 10:80:10 to 60:10:30, about 60:30:10 to 30:50:20, or about 45:45:10 to 35:45:20. As one of skill would understand, the chemical structures of branched amine polymer can vary greatly and can be very complex. In an aspect, the branched amine polymer can have a molecular weight of about 100 to 100,000 g/mol, about 200 to 30,000 g/mol or about 600 to 5,000 g/mol.

Dendritic amine polymers can be defined as containing only primary and tertiary amines, where groups of repeat units are arranged in a manner that is necessarily symmetric in at least one plane through the center (core) of the molecule, where each polymer branch is terminated by a primary amine, and where each branching point is a tertiary amine. The core or central linkage is the same as the branching amines (e.g., ethylenimine core and ethylenimine branches, propylenimine core and propylenimine branches). The ratio of primary to tertiary can be about 1 to 3. In an aspect, the dendritic amine polymer can have a molecular weight of about 100 to 100,000 g/mol, about 200 to 30,000 g/mol or about 280 to 3,000. Hyperbranched amine polymers can be defined as having chemical structure resembling dendritic amine polymer, but containing defects in the form of secondary amines (e.g., linear subsections as would exist in a branched polymer), in such a way that provides a random chemical structure instead of a symmetric chemical structure. The hyperbranched amine polymers do not overlap branch amine polymers or dendritic polymers. In a hyperbranched chemical structure, the ratio of primary to secondary to tertiary can be about 65:5:30 to 30:10:60. In an aspect, the hyperbranched amine polymer can have a molecular weight of about 100 to 100,000 g/mol, about 200 to 30,000 g/mol or about 600 to 10,000 g/mol.

In an aspect, linear, hyperbranched and branched amine polymers have secondary amines and dendritic amines do not, which may be advantageous since secondary amines bond strongly to CO2.

In an aspect, the amine polymer can be polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, polystyrene-divinylbenzene polymer functionalized with amine such as alkylbenzylamine moieties, or other amine polymer, where each can be branched, hyperbranched, dendritic, or linear.

In an embodiment, the size (e.g., length, molecular weight), amount (e.g., number of distinct amine polymers), and/or type of amine polymer, can be selected based on the desired characteristics of the porous structure (e.g., CO2 absorption, regenerative properties, oxidative stability, loading, and the like).

In an aspect, the phenyl amine containing molecules can function to scavenge hydroperoxide, radicals, or both hydroperoxide and radicals. In an aspect, the phenyl amine containing molecules can be diphenylamines, and substituted (e.g., alkyl (e.g., C1 to C4 or C1 to C8, or C1 to C12 groups) substituted) diphenylamines. The phenyl amines can include one or a combination of the following: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’- diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, N,N’-di-sec-butyl-p-phenylenediamine, bis(4-tert-butylphenyl)amine, bis(4-nitrophenyl)amine, 4-isopropylaminodiphenylamine, 4,4'- bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1 ,4-phenylenediamine, 4,4’-dimethyldiphenylamine, 3,5-di-tert-butylaniline, 2,2'-dinapthylamine, 4,4’- dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, 2,6-bis(2-pyridyl)-4(1 H)- pyridone, and the like. In an aspect, phenyl amines can include one or a combination of the following: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’-diphenyl-p- phenylenediamine, N’N’-diphenylbenzidine, bis(4-tert-butylphenyl)amine, bis(4- nitrophenyl)amine , 4,4'-bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1 ,4- phenylenediamine, 4,4’-dimethyldiphenylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)-pyridone. In an aspect, phenyl amines can include one or a combination of the following: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, bis(4- tert-butylphenyl)amine, and 4,4’-dimethyldiphenylamine.

In an aspect, it can be advantageous to improve the stability of the CO₂-philic phase to process conditions relevant to use of the sorbent in a CO₂ separation process, particularly during sorbent regeneration (process cycles that raise the temperature of the sorbent to remove bound CO2). It can also be advantageous to improve the stability of the CO₂-phi lie phase to conditions relevant to storage of the sorbents when they are not being utilized in a process or plant. Sorbents that have a CC>2-philic phase with improved stability with respect to process conditions including sorbent regeneration, storage, or both process conditions including sorbent regeneration and storage are valuable.

Evaluating the oxidative stability of materials in environments that contain oxygen and CO2 is useful due to the fact that during regeneration processes, desorbed CO2 is present at different concentrations in addition to oxygen at elevated temperatures, and can impact the stability of the material. Separately, evaluating the oxidative stability of materials with oxygen only (air) is a useful way to evaluate the shelf life of a material when it is stored at ambient conditions.

As described above, the CC>2-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO₂ binding molecules) can be homogeneous or heterogeneous. When the CC>2-philic phase is heterogeneous, the phenyl amine containing molecules and the CO2 binding molecules can be present in a variety of ways. For example, the phenyl amine containing molecules and the CO₂ binding molecules can be mixed and then applied or incorporated with the structure. In another example, the phenyl amine containing molecules and the CO₂ binding molecules can be applied or incorporated separately but once applied or incorporated, the phenyl amine containing molecules and the CO2 binding molecules form the CO₂-philic phase. In an aspect, the phenyl amine containing molecules and the CO2 binding molecules can be applied or incorporated separately to form a layer of the CO2-philic phase on a support, such as on the surface of pores of the support. In another aspect, a mixture of the phenyl amine containing molecules and the CO2 binding molecules can be applied to form a layer on a support (e.g., such as on the surface of pores of the support), and optionally one or both of the phenyl amine containing molecules and the CO₂ binding molecules can be applied or incorporated separately onto the layer on the support (e.g., such as on the surface of pores of the support). In another aspect, independent of or used in combination with other aspects such as those described above, one of both of the phenyl amine containing molecules and the CO2 binding molecules can be used to form a part of or all of the support, where CO₂-philic phase functions as described herein. Various combinations are contemplated and are part of the present disclosure. Additional ways in which to apply, use, or incorporate the CO₂-philic phase homogeneously and/or heterogeneously are described herein and below.

As described herein, the sorbent includes the CO₂-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO₂ binding molecules) and the support. The support includes a surface (e.g., a surface that can be exposed to a gas including CO₂ during regular use and/or that can interact with the CO₂-philic phase). The surface can be the surface of pores and/or other surfaces that the CO₂-phi lie phase contacts or interacts with.

In an aspect, the CO₂-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO₂ binding molecules) can be disposed on or within a support to form a sorbent. The CO₂-philic phase can be disposed on the surface of the support, and/or within pores of the support, and/or on exterior surface of a support or any combination thereof. In an aspect, the CO₂-philic phase can be a coating on the surface of the porous material, a monolayer on the surface of the porous material, a self-assembled monolayer on the surface of the porous material, a bulk phase within the pores of the porous material, a coating on the exterior surface of the porous material, and the like.

In an aspect, the support can be made of one or more types of materials such as ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymer of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, boron-nitride fiber, and the like. In another aspect, the support can be made of materials that also include the CO₂- philic phase.

The metal oxide support can be selected from cordierite, alumina (e.g., y-alumina, 0- alumina, 5-alumina), cordierite-a-alumina, silica, aluminosilicates, zirconia, germania, magnesia, titania, hafnia, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, and combinations thereof. In cases where the oxide contains a formal charge, the charge can be balanced by appropriate counter-ions, such as cations of NR₄, Na, K, Ca, Mg, Li, H, Rb, Sr, Ba, Cs or anions including phosphate, phosphite, sulfate, sulfate, nitrate, nitrite, chloride, bromide and the like. The metal oxide can contain dopants such as zirconium, iron, tin, silicon, titanium, magnesium, and combinations thereof. It is known that metal oxides can contain acid, base, and neutral sites on their surfaces and that dopants can alter the amount and strength of acid and base sites on the surfaces.

In an aspect, the polymer support can be a polymer and/or copolymer of polyolefin(s), polyester(s), polyurethane(s), polycarbonate(s), polyetheretherketone(s), polyphenylene oxide(s), polyether sulfone(s), melamine(s), polyamide(s), polyvinylbenzene, polystyrene- divinylbenzene, polyurethane, polyacrylates, polystyrenes, polyacrylonitriles, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose, or combinations thereof.

The support can be porous (e.g., macroporous, mesoporous, microporous, or mixtures thereof (e.g., where a macroporous surface can include mesopores, and/or micropores, within one or more of the macropores, where a mesoporous surface can include micropores, and so on)). In an aspect, the porous structure is mesoporous. The pores can extend through the porous structure or porous layer or only extend to a certain depth. The macropores of the porous structure can have pores having a diameter of about 100 nm to 10,000 nm, a length of about 500 nm to 100,000 nm and a volume of 0.2-1 cc/g. The mesopores of the porous structure can have pores having a diameter of about 5 nm to 100 nm, a length of about 10 nm to 10,000 nm, and a volume of 0.1-2 cc/g. The micropores of the porous structure can have pores having a diameter of about 0.5 to 5 nm, a length of about 0.5 nm to 1000 nm and a volume of about 0.1-1 cc/g.

The support can be porous and have a porosity of at least 90%, at least 85%, at least 80%, at least 75%, at least 70%, at least 65%, at least 60%, or about 60 to 90%. In some embodiments, the support can have a surface area of 1 m²/g or more, 10 m-7g or more, 100 m²/g or more, 150 m²/g or more, 200 m²/g or more, or 250 m²/g or more, 500 m²/g or more, 1000 m²/g or more.

In an embodiment, the CCh-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO2 binding molecules) can be physically impregnated in the internal volume pores of the porous structure and not covalently bonded to the internal surface of the pores of the porous structure, can be grafted (e.g., covalently bonded directly or indirectly) to the internal surface of the pores of the porous structure, or a combination thereof. In an embodiment, the COs-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO2 binding molecules) can be covalently bonded (e.g., directly to the surface or via a linker group) to the surface of the material, which may include the internal surface of pores for a porous layer or porous structure. In an aspect, the covalent bonding can be achieved using known techniques in the art for bonding sorbents. In regard to the CC -philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO₂ binding molecules) being physically impregnated in the pores of the porous structure and not covalently bonded to the internal surface of the pores of the porous structure, the CO2-philic phase can be confined within the pores of the support, but not bonded to the surface. In yet another embodiment, the CO2-philic phase (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO2 binding molecules) is present in a plurality of pores (internal volume) of the porous structure (“porous structure’’ can include a structure having pores in its surface or a structure having a porous layer or coating on the surface of the structure (where the structure itself may or may not be porous)), where the CO2- philic phase has a loading of about 10% to 75% by weight of the support. In regard to the loading, the loading is determined by thermogravimetric analysis (TGA).

In an embodiment, the support can include a surface layer on the surface of the pores of the support that can bond with the COz-philic phase. In an aspect, the surface layer can include organically modified moieties (e.g., alkyl groups, amines, thiols, phosphines, and the like) on the surface (e.g., outside and/or inside surfaces of pores) of the material. In an embodiment, the surface layer can include surface alkyl groups, amines, thiols, phosphines, and the like, that the COs-philic phase can directly covalently bond and/or indirectly covalently bond (e.g., covalently bond to a linker covalently bonded to the material). In an embodiment, the surface layer can include an organic polymer having one or more of the following groups: alkyl groups, amines, thiols, phosphines, and the like. In another embodiment, the structure can be a carbon support, where the carbon support can include one or more of the following groups: alkyl groups, amines, thiols, phosphines, and the like.

In an embodiment, the CO₂-philic phase can occupy about 10 to 100% of the mesopore volume of the support, or can occupy about 30 to 90% of the mesopore volume of the support, or can occupy about 40 to 80% of the mesopore volume of the support, or can occupy about 50 to 70% of the mesopore volume of the support.

The process of making a formed support or structure described above and herein can be used to create any of the structures listed in this paragraph and those in the following paragraphs. The sorbent, comprising the CCh-philic phase and the support, can be formed into or applied to a structure. In an aspect, the CC>2-philic phase and the support can form 100% of the structure or less than 100% (e.g., each combination of ranges between about 10%, about 20%, about 30%, about 40%, about 50% and about 60%, about 70%, about 80%, about 90%, about 99% such as about 10-99%, about 10 to 80%, about 10 to 50%, about 50 to 99%, about 50 to 90%, about 50 to 80%), where a sufficient amount of sorbent is on the surface of the structure to absorb the desired amount of CO2. In an aspect, the structure can be a honeycomb, a laminate sheet, a foam, fibers, minimal surface solids, powder trays, pellets, powder, and the like or a combination of two or more of the foregoing.

In an aspect, the structure can be porous and have a porosity of at least 90%, at least 85%, at least 80%, at least 75%, at least 70%, at least 65%, at least 60%, or about 60 to 90%.

In an aspect, the porosity of the structure can be comprised of macropores, mesopores, and/or micropores. In an aspect, the COz-philic phase is predominantly (e.g., about 40 to 100% or about 50 to 90%, or about 60 to 80%) located within the mesopores of the structure.

In an aspect, the structure can be comprised entirely of sorbent or can contain another substrate material such as ceramic, metal, metal oxide, plastic or another material. The structure can be a porous substrate and can also include a porous coating on some or all parts of the porous substrate, where the COz-philic phase can be present in the pores of one or both of the porous substrate and the porous coating.

When the structure is comprised entirely of sorbent (e.g., homogeneous or heterogeneous combination of the phenyl amine containing molecules and the CO2 binding molecules and a support), it can be formed by extrusion, molding, 3D printing, and the like, for example. The structure can be formed using support material without the COz-philic phase or using the support with the COz-philic phase already incorporated. When formed without using the COz-philic phase, the COz-philic phase can be incorporated into the structure through an impregnation, grafting, or other functionalization technique.

In a particular aspect, the support material can be applied to a substrate as a porous coating (also referred to as a “washcoat”) on the surface of the substrate. In an embodiment, the porous coating can be a foam such as a polymeric foam (e.g., polyurethane foam, a polypropylene foam, a polyester foam, and the like), a metal foam, or a ceramic foam. The porous coating can include a metal-oxide layer (e.g., such as a foam). The metal-oxide layer can be silica or alumina on the surface of the substrate, for example. The porous coating can be present on the surface of the substrate, within the pores or voids of the substrate, or a combination thereof. The porous coating can be about 50 pm to 1500 pm thick and the pores can be of the dimension described above and herein.

In an aspect, the support material, the substrate, and/or the structure can be made of a ceramic substrate such as cordierite, alumina (e.g., y-alumina, 0-alumina, 5-alumina), cordierite- a-alumina, silica, aluminosilicates, zirconia, germania, magnesia, titania, hafnia, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, and combinations thereof. The metal or metal oxide structure can be aluminum, titanium, stainless steel, a Fe-Cr alloy, or a Cr-AI-Fe alloy. In cases where the oxide contains a formal charge, the charge can be balanced by appropriate counter-ions, such as cations of NR₄, Na, K, Ca, Mg, Li, H, Rb, Sr, Ba, Cs or anions including phosphate, phosphite, sulfate, sulfate, nitrate, nitrite, chloride, bromide and the like.

In an aspect, the support material, the substrate, and/or the structure can be made of a plastic substrate that can be made of a polymer and/or copolymer of polyolefin(s), polyester(s), polyurethane(s), polycarbonate(s), polyetheretherketone(s), polyphenylene oxide(s), polyether sulfone(s), melamine(s), polyamide(s), polyvinylbenzene, polystyrene-divinylbenzene, polyurethane, polyacrylates, polystyrenes, polyacrylonitriles, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose, or combinations thereof. in an embodiment, the structure can be a honeycomb structure such as a honeycomb monolith structure that includes channels. The honeycomb structure can have a regular, corrugated structure. The honeycomb monolith structure can have a length and width on the order of centimeters to meters while the thickness can be on the order of millimeters to centimeters or more. In an aspect, the honeycomb monolith structure does not have fibrous dimensions. In other words, the honeycomb structure can be a flow-through substrate comprising open channels defined by walls of the channels. The channels can have about 50 to about 900 cells per square inch. The channels can be polygonal (e.g., square, triangular, hexagonal, octagonal) sinusoidal, circular, or the like, in cross-section. Along the length of the channel, the channel length can have a configuration that is straight, zig-zag, skewed, or herringbone in shape. The length of the channel can be 1 mm to 10s or 100s of cm or more The channels can have walls that are perforated or louvered. In an aspect, the sorbent can be disposed in the pores of the honeycomb structure and/or in the pores of a porous layer on the surface of the honeycomb structure. The honeycomb structure can have a geometric void fraction, otherwise known as the open face area, of between 0.3 to 0.95 or about 0.5 to 0.9.

In an embodiment, the honeycomb structure can comprise an inlet end, an outlet end, and inner channels extending from the inlet end to the outlet end. In some embodiments, the honeycomb comprises a multiplicity of cells extending from the inlet end to the outlet end, the cells being defined by intersecting cell or channel walls. In an aspect, the honeycomb structure and/or substrate can be ceramic (e.g., of a type produced by Corning under the trademark Celcor®) that can be used with the sorbent in accordance with the principles of the present disclosure. The sorbent can be coated or otherwise immobilized on the inside of the pores of the ceramic honeycomb structure and/or within a porous layer on the surface of the ceramic honeycomb structure. In an aspect, the porous coating can include a metal-oxide layer such as silica or alumina on the surface of the substrate. In an embodiment, the metal-oxide layer can be mesoporous and macroporous. The honeycomb monolith may have a depth of 3 inches to 10 feet or about 3 and 24 inches.

In an aspect, the structure can be laminate sheets. Laminate sheets are structures containing a one-dimensional wall structure, whereby sheets are stacked upon one and other with space in between each sheet such that gas can flow between the sheets.

In an aspect, the structure can be a foam. Foams are structures with an irregular channel structure surrounded by an irregular solid structure. The solid structure is interconnected such that the foam material is self-standing.

In an aspect, the structure can be a plurality of fibers. Fibers are structures with high aspect ratio, and in gas contacting applications can be arranged in a regular array amongst one another when supported at least on one end of the fiber. The fibers can be solid or hollow.

In an aspect, the structure can be a minimal surface solid. Minimal surface solids are structures often used in packing for distillation and absorption systems to increase contact area with a material and a fluid. Minimal surface area solids are geometries that have zero mean surface area and include shapes such as gyroids. Gyroids can be sinusoidal, for example.

In an aspect, the structure can be a powder tray. Powder trays are structures whereby trays hold loose powder or pellets of the sorbent of the present disclosure to form a structured contactor without the material forming a self-standing structure by itself. Powder trays can be arranged in stacked layers to form sheets thereby forming a structure similar to a laminate. These layers can be created using flexible sheets, stiff sheets, or other flat surface that is mounted on a stiff frame structure. Powders are loose, free flowing solids with small characteristic particle diameter such as to provide a powdery consistency. Pellets are beads, balls, or other compacted structures used to provide structure and surface area to sorbents

In an aspect, the structure can be sorbent particle volumes. Sorbent particle volumes can be contained by one or more walls such that gas can pass through them while keeping the sorbent contained. Sorbent particle volumes can be arranged relative to other sorbent particle volumes such as to approximate a honeycomb, fiber, or other structured contactor with a solid body. In an aspect, the sorbent (e.g., structure) in the form of a contactor is an efficient embodiment for an effective method for capturing CO2 from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas, or other gasses containing CO2) because a structured contactor, or a contactor, can be engineered to provide high surface area and low pressure drop for the air processing. Contactors can take the forms described of a honeycomb, a laminate sheet, a foam, fibers, minimal surface solids, powder trays, pellets, powder, and the like or a combination of two or more of the foregoing.

In another aspect, the present disclosure provides for sorbents and contactors that include a CC philic phase and a support, where the CC philic phase includes CO2 binding molecules and bicarbonate salts. In addition, the CC>2-phi lie phase can optionally include the phenyl amine containing molecules, such as those described herein. The CC>2-phi lie phase (e.g., homogeneous or heterogeneous combination of the bicarbonate salts and the CO2 binding molecules and optionally including the phenyl amine containing molecules) can be homogeneous or heterogeneous. The bicarbonate salts may be sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, aminoguanidine bicarbonate, cesium bicarbonate, choline bicarbonate, tetraalkylammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate and the like. The ratio of the amount of bicarbonate salts to CO2 binding moieties can be about 0.0001 to 1 mole bicarbonate salts to mole CO2 binding moiety or about 0.01 to 0.5 mole bicarbonate salts to mole CO2 binding moiety. Optionally, when the phenyl amine containing molecules are present, the ratio of the amount of phenyl amine containing molecules to CO2 binding moieties can be about 0.0001 to 1 mole phenyl amine containing molecule to mole CO2 binding moiety or about 0.01 to 0.5 mole phenyl amine containing molecule to mole CO2 binding moiety.

Although not intending to be bound by theory, the addition of phenyl amine and/or bicarbonate salt containing molecules to the CO₂-philic phase allows for the ability to tune the properties of the CO₂-philic phase. The amount, type, and mixture quantity of phenyl amine and/or bicarbonate salt molecule can be tuned and changed to achieve the desired properties of the CO₂-philic phase. Tuning the CC>2-philic phase can result in one or a combination of the following that yield an improved CO2 sorbent: increased lifetime due to a reduction in the rate of oxidative degradation, increase in amine efficiency of the sorbent, increase in the CO2 swing capacity of the sorbent in an adsorption/desorption process, increase in the equilibrium capacity of the sorbent.

The support for this embodiment can also be the same type of support and/or structure as provided above (e.g., a honeycomb, a laminate sheet, a foam, fibers, minimal surface solids, powder trays that include the sorbent, pellets, powder), having the same dimensions, materials, and the like as described above. The structures can be high surface area supports that can have a surface area of about 1 m²/g or more, 10 m²/g or more, 100 m²/g or more, 150 m²/g or more, 200 m²/g or more, or 250 m²/g or more, 500 m²/g or more, 1000 m²/g or more.

As described above, the CC>2-philic phase can be homogeneous or heterogeneous. When the CC>2-philic phase is heterogeneous, the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules can be present in a variety of ways. For example, the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules can be applied or incorporated separately but once applied or incorporated, the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules for the CC>2-philic phase. In an aspect, the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules applied or incorporated separately to form a layer of the CC>2-philic phase on a support, such as on the surface of pores of the support. In another aspect, a mixture of the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules can be applied to form a layer on a support (e.g., such as on the surface of pores of the support), and optionally one or both of the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules can be applied or incorporated separately onto the layer on the support (e.g., such as on the surface of pores of the support). In another aspect, independent of or used in combination with other aspects such as those described herein and above, one of both of the bicarbonate salts (and optionally phenyl amine containing molecules) and the CO2 binding molecules can be used to form a part of or all of the support, where CC>2-philic phase functions as described herein. Additional ways in which to apply, use, or incorporate the CO2- philic phase homogeneously and/or heterogeneously (e.g., CO2 binding molecules and bicarbonate salts; CO₂ binding molecules and phenyl amine containing molecules; or CO₂ binding molecules and phenyl amine containing molecules and bicarbonate salts) are described herein and above.

In an aspect, the modified CC>2-philic phase (e.g., CO2 binding molecules and bicarbonate salts; CO2 binding molecules and phenyl amine containing molecules; or CC>2 binding molecules and phenyl amine containing molecules and bicarbonate salts) maintains high CO2 capacities relative to the native CC philic phase that is not modified. The sorbents lose less of the capacity to capture CO2 following oxidative exposures compared to sorbents created without the improvement to the CC>2-philic phase, thereby providing them with longer commercial lifetime. Now having described embodiments of the sorbent and structure, additional details regarding the systems and methods of the present disclosure are provided. The present disclosure provides for methods of capturing CO2 from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas, or other gasses containing CO₂). The method includes introducing the ambient air to the sorbent (e.g., structure), heating the sorbent (e.g., about 10 to 200° C above the regular sorbent temperature to absorb the CO2) to at least a first temperature to controllably release the CO₂; and collecting the CO₂ in a CO₂ collection device. The temperature increase in the sorbent can be performed by contacting the sorbent with a gas at elevated temperature, contacting the sorbent with a fluid at an elevated temperature, contacting the sorbent with a heat exchanger with hot fluid or gas running through it, by heating the walls of the container, vessel, or other containment device that contains the sorbent, or by contacting the sorbent with steam (e.g., the steam may be at a temperature between 60 to 200° C, and be saturated or superheated). In an aspect, the method can be implemented using the system described below.

The present disclosure provides for systems and devices for capturing CO₂ from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas, or other gasses containing CO₂) where removal of CO₂ is important. In general, the system includes a first device configured to introduce the ambient air or other gas mixture to the sorbent or contactor, where the sorbent or contactor includes those described herein. The sorbent is exposed to the ambient air or other gas mixture for a period of time (e.g., hours). In a particular aspect, the sorbent is a honeycomb monolith that has an open face area of between 0.3-0.95. The first device is configured to deliver the ambient air, for example, to the honeycomb monolith at a velocity of between 0.25-10 m/s. After the desired amount of time, a second device configured to heat the sorbent containing bound CO₂ to at least a first temperature (e.g., about 40 to 200° C, about 50 to 200° C, or about 60 to 200° C) to release the CO₂. The second device of the system can operate to desorb CO₂ by the sorbent. The second device can include components to support temperature swing, pressure swing, steam swing, concentration swing, combinations thereof, or other dynamic processes to desorb the CO₂. In an embodiment, the steam swing process can include exposing the sorbent to steam, where the temperature of the steam is about 60° C to 150° C and the pressure of the steam is about 0.2 bara to 5 bara. A third device is configured to collect the released CO₂. The system can be operated so that the sorbent absorbs and desorbs the CO₂ in an efficient and cost-effective manner.

Aspects of the present disclosure can be described by the following paragraphs. The present disclosure provides for a sorbent comprising: a CO2-philic phase and a support, wherein the CC philic phase includes CO2 binding molecules moieties and phenyl amine containing molecules, wherein the CO2 binding molecules include CO2 binding moieties. The CO₂-philic phase can be an amine. The amine can be an amine polymer. The amine polymer can be branched, hyperbranched, dendritic, or linear. The amine polymer can be one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene-divinylbenzene polymer functionalized with amine, or other amine polymers. The CC>2-philic phase can be homogeneous. The CC>2-philic phase can be heterogeneous. The phenyl amine containing molecules can be selected from diphenylamines and substituted diphenylamines. The phenyl amine containing molecules can be selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’-diphenyl-p- phenylenediamine, N’N’-diphenylbenzidine, N,N’-di-sec-butyl-p-phenylenediamine, bis(4-tert- butylphenyl)amine, bis(4-nitrophenyl)amine , 4-isopropylaminodiphenylamine, 4,4'- bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 4,4’- dimethyldiphenylamine, 3,5-di-tert-butylaniline, 2,2'-dinapthylamine, 4,4’- dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)- pyridone. The phenyl amine containing molecules can be selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’-diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, bis(4-tert-butylphenyl)amine, bis(4-nitrophenyl)amine , 4,4'- bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 4,4’- dimethyldiphenylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)-pyridone. The phenyl amine containing molecules can be selected from one or a combination of 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, bis(4-tert- butylphenyl)amine, and 4,4’-dimethyldiphenylamine. The amine can be physically impregnated into pores of the support. The amine can be physically impregnated onto the surface of the support. The amine can be covalently bonded to the surface of the support. The support can be ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymers of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

The present disclosure provides for a sorbent comprising: a CO2-philic phase and a support, wherein the CC philic phase includes CO2 binding molecules moieties and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties. The CO2- philic phase can be an amine. The amine can be an amine polymer. The amine polymer can be branched, hyperbranched, dendritic, or linear. The amine polymer ban be one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene-divinylbenzene polymer functionalized with amine, or other amine polymers. The CC>2-philic phase can be homogeneous. The CC>2-philic phase can be heterogeneous. The bicarbonate salt can be selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, aminoguanidine bicarbonate, cesium bicarbonate, choline bicarbonate, tetraalkylammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof. The amine can be physically impregnated into pores of the support. The amine can be physically impregnated onto the surface of the support. The amine can be covalently bonded to the surface of the support. The support can be ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymer of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

The present disclosure provides for a sorbent comprising: a CO2-philic phase and a support, wherein the CC philic phase includes CO2 binding molecules moieties and both phenyl amine containing molecules and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties. The CC>2-philic phase can be an amine. The amine can be an amine polymer. The amine polymer can be branched, hyperbranched, dendritic, or linear. The amine polymer ban be one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene-divinylbenzene polymer functionalized with amine, or other amine polymers. The CC>2-philic phase can be homogeneous. The CC>2-philic phase can be heterogeneous. The phenyl amine containing molecules can be selected from diphenylamines and substituted diphenylamines. The phenyl amine containing molecules can be selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’-diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, N,N’-di-sec-butyl-p- phenylenediamine, bis(4-tert-butylphenyl)amine, bis(4-nitrophenyl)amine , 4- isopropylaminodiphenylamine, 4,4'-bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'- phenyl-1 ,4-phenylenediamine, 4,4’-dimethyldiphenylamine, 3,5-di-tert-butylaniline, 2,2'- dinapthylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6- bis(2-pyridyl)-4(1 H)-pyridone. The phenyl amine containing molecules can be selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’-diphenyl- p-phenylenediamine, N’N’-diphenylbenzidine, bis(4-tert-butylphenyl)amine, bis(4- nitrophenyl)amine , 4,4'-bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1 ,4- phenylenediamine, 4,4’-dimethyldiphenylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)-pyridone. The phenyl amine containing molecules can be selected from one or a combination of 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, bis(4-tert-butylphenyl)amine, and 4,4’-dimethyldiphenylamine. The bicarbonate salt can be selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, aminoguanidine bicarbonate, cesium bicarbonate, choline bicarbonate, tetraalkylammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof. The amine can be physically impregnated into pores of the support. The amine can be physically impregnated onto the surface of the support. The amine can be covalently bonded to the surface of the support. The support can be ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymer of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

The present disclosure provides for a contactor, comprising a structure and the sorbent as described herein or above. The structure can be selected from a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, or a combination of these.

The present disclosure provides for a system for capturing CO2 from a gas, optionally the gas is ambient air, comprising: a first device configured to introduce the gas to the sorbent or contactor as described above or herein to bind CO2 to the sorbent; a second device configured to heat the sorbent containing bound CO2 to at least a first temperature to release the CO2; and a third device configured to collect the released CO2. After being heated the sorbent can be regenerated so it able to absorb CO2 from the gas. The sorbent can be in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof. The honeycomb has an open face area of between 0.3-0.95. The gas approaches the honeycomb at a velocity of between 0.25-10 m/s. The system is configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO₂.

The present disclosure provides for a method of capturing CO2 from gas optionally the gas is ambient air comprising: introducing the ambient air to the sorbent of as described above or herein to bind CO2 to the sorbent; heating the sorbent to at least a first temperature to controllably release the CO2; and collecting the CO2 in a CO2 collection device. Heating the sorbent regenerates the sorbent so it is able to absorb CO2 from ambient air. The sorbent can be heated by contacting it with steam. The method can be configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO2. The sorbent can be in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof. The present disclosure provides for systems for implementing the method as described above or herein.

The present disclosure provides for a system for implement the method as described above and herein.

Examples

The removal of CO2 from ambient air through engineered chemical processes, otherwise known as Direct Air Capture (DAC), is emerging as an important environment technology for the mitigation of climate change. DAC is a technology that can provide negative emissions, removing CO2 from the atmosphere. However, the current DAC technology is expensive thereby limiting its deployment. Therefore, improvements to DAC technology are needed. Many DAC technologies rely on solid sorbent materials as a medium to perform the separation of CO2 from the air. These sorbents are generally applied in temperature swing processes, where at low temperature CO2 from the air binds to the sites within them, and then at high temperature the CO2 is released into a concentrated product that can be sequestered or sold as a product. Many DAC sorbents utilize amines to bind CO2 in this manner. Certain amine types can be effective at binding CO2 from low concentrations such as that found in the air (400 ppm).

While some amine types are effective at binding CO2 from ambient air, they slowly oxidize in air from ambient oxygen. This effect is exacerbated in process cycles that raise the temperature of the sorbent to remove bound CO2, thereby creating accelerated oxidative degradation that reduces the lifetime of the CO2 sorbents. Therefore, sorbents with improved oxidative stability that are effective at removing CO2 from ambient air are needed.

Some sorbents used in DAC processes are composite materials, containing a CC philic phase (e.g., CO2 binding molecules and bicarbonate salts; CO2 binding molecules and phenyl amine containing molecules; or CO₂ binding molecules and phenyl amine containing molecules and bicarbonate salts) that is distributed in or within a solid material that provides it with surface area. The CC>2-philic phase can be grafted to the solid surface, physically impregnated into the pores of the solid material, or physically supported on the surface of the solid material. The CC>2-philic phase of these sorbents can be amines or other molecules that can bind CO2. In some cases, the amines can be polymeric amines such as polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polybutylamine or others. These polymeric amines can be linear, branched, hyperbranched, dendritic, or take the form some other macromolecule. In other cases, the amines can be small molecules such as TEPA, TPTA or others. In other cases, the amines can be aminosilanes. The solid support material can be a metal oxide, carbon, metal, or other structure that can provide ample surface area for the CO2-philic phase to be deposited to allow for useful CO2 adsorption and desorption capacities and kinetics. In this way, the solid support material is functionalized with the COz-philic phase to create a composite sorbent.

The sorbents can be formed or incorporated into macrostructures, or contactors, to provide advantages in applications such as DAC. Such structures can be honeycomb monoliths, laminate sheets, pellets, or other structures that can provide a high geometric surface area for air or CO2 containing gasses to efficiently contact the sorbent such that the CO2 can bind to the sorbent.

The sorbents can be utilized in processes to capture CO2 from air or a variety of other gas stream such as flue gas, natural gas and others. These processes are known as “CO2 Capture Processes”. CO2 capture processes can utilize temperature swing, concentration swing, pressure swing, steam stripping or other swing techniques to remove CO2 that has been bound the surface of the sorbent.

There has been relatively little development of improved CO2 sorbents utilizing polyethylenimine, and especially for DAC applications.

Now having described the embodiments of the present disclosure, in general, the following examples describes some additional embodiments of the present disclosure. While embodiments of the present disclosure are described in connection with these examples and the corresponding text and figures, there is no intent to limit embodiments of the present disclosure to these descriptions. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of the present disclosure.

Figure 1 shows the primary components of the sorbent system. The sorbent system is comprised of a support material and a CO₂-phil ic phase. In the schematic shown, a single CO₂- philic phase is shown incorporated into a single support. The CC>2-philic phase shown is polyethyleneimine (PEI). One known adsorption product of CO2 and PEI is shown, ammonium carbamate. Mesoporous alumina is shown as a support.

Example: Schematic of honeycomb monolith structure containing a sorbent washcoat (e.g., CCh-philic phase such as one including: CO2 binding molecules and bicarbonate salts; CO2 binding molecules and phenyl amine containing molecules; or CO2 binding molecules and phenyl amine containing molecules and bicarbonate salts) Figure 2 shows one embodiment of a honeycomb monolith contactor. The figure shows the primary geometrical features of a honeycomb monolith, having straight, flowthrough channels surrounded on all sides by walls. The figure schematically shows a washcoat applied to the walls, where the washcoat is comprised of sorbent. The sorbent is comprised of a support material and a CC>2-philic phase, such as PEI.

Example: Phenyl amine and bicarbonate salt molecules evaluated as additives to polyethylenimine (PEI)

A variety of additive molecules were evaluated to assess their ability to reduce the oxidation rate of PEI in sorbents. The categories of additive molecules tested were phenyl amines, and bicarbonate salts. These molecules are known to be effective at reducing the oxidation rate of other polymer systems used in commercial products such as poly(ethylene) and poly(propylene). However, their effectiveness in amine polymers that are used to create effective CC>2-philic phases in CO2 sorbents is not obvious.

Example: Preparation of improved CO2 sorbents containing polyethylenimine (PEI) and phenyl amines

Branched polyethylenimine (PEI), MW 800 is available from Sigma Aldrich. The phenyl amine compounds and their ratios used are listed in the table below. The PEI was dissolved in a solution of methanol, after which the amine was added in the specified ratio(s) of mol amine per mol of N present in PEI and stirred until homogenous. In the cases of Amine 4 and Amine 13, the PEI was dissolved in a solution of methanol, and the amine (optionally Amine 4 or Amine 13), was dissolved in toluene in a ratio corresponding to 0.1 mol amine per mol of N present in PEI. The two solutions were then mixed and stirred until homogenous. Then, for all cases, a mesoporous alumina was dispersed in the mixture. After stirring for >4h, the solvent was removed using rotary evaporation and subsequent drying in a vacuum oven at 100° C. Mass ratios of the alumina and PEI/amine were controlled such as to achieve 40-80% filling of the mesopores of the mesoporous alumina with PEI/amine mixture. The resultant composite sorbents were of a powdery consistency.

Table 1 : Details for preparation of phenyl amine containing CO2 sorbents

Example: Preparation of improved CO2 sorbents containing polyethylenimine (PEI) and 4,4’-Bis (a,a-dimethybenzyl) diphenylamine (Amine 1) on different mesoporous supports

Branched poly(ethylenimine) (PEI), MW 800 is available from Sigma Aldrich. The amine compound used was 4,4’-Bis (a,a-dimethybenzyl) diphenylamine from Sigma Aldrich (CAS no. 10081-67-1) and is a commercially available secondary aromatic amine. The mesoporous supports used were two commercially available mesoporous aluminas (AI₂O₃ 1 , AI₂O₃ 2), a commercially available titania, and a commercially available silica-doped alumina. The PEI was dissolved in a solution of methanol, after which the amine was added in a ratio corresponding to 0.1 mol amine per mol of N present in PEI and stirred until homogenous. Then, the mesoporous support was dispersed in the mixture. After stirring for >4h, the solvent was removed using rotary evaporation and subsequent drying in a vacuum oven at 100° C. Mass ratios of the mesoporous support and PEI/amine were controlled such as to achieve 40-80% filling of the mesopores of the mesoporous support with PEI/amine mixture. The resultant composite sorbents were of a powdery consistency.

Example: Preparation of improved CO2 sorbent containing polyethylenimine (PEI) and bicarbonate salts

Branched polyethylenimine (PEI), MW 800 is available from Sigma Aldrich. The bicarbonate salts and their ratios used are listed in the table below. The PEI was dissolved in a solution of water, after which the bicarbonate was added in the specified ratio(s) of mol bicarbonate per mol of N present in PEI and stirred until homogenous. Then, a mesoporous alumina was dispersed in the mixture. After stirring for >4h, the solvent was removed using rotary evaporation and subsequent drying in a vacuum oven at 100° C. Mass ratios of the alumina and PEI/bicarbonate were controlled such as to achieve 40-80% filling of the mesopores of the mesoporous alumina with PEI/bicarbonate mixture. The resultant composite sorbents were of a powdery consistency.

Table 2: Details for the preparation of bicarbonate containing CO2 sorbents

Example: Preparation of improved CO2 sorbent containing polyethylenimine (PEI), phenyl amine, and bicarbonate salt

Branched poly(ethylenimine) (PEI), MW 800 is available from Sigma Aldrich. The amine compound used was 4,4’-Bis (a,a-dimethybenzyl) diphenylamine from Sigma Aldrich (CAS no. 10081-67-1) and the bicarbonate compound used was sodium bicarbonate from Sigma Aldrich (CAS no. 144-55-8). The PEI was dissolved in a solution of methanol, after which the amine was added in a ratio corresponding to 0.1 mol amine per mol of N present in PEI. The bicarbonate was dissolved in a solution of water at a ratio also corresponding to 0.1 mol bicarbonate per mol of N present in PEI. The two mixtures were added together and stirred until homogenous. Then, a mesoporous alumina was dispersed in the mixture. After stirring for >4h, the solvent was removed using rotary evaporation and subsequent drying in a vacuum oven at 100° C. Mass ratios of the alumina and PEI/amine/bicarbonate were controlled such as to achieve 40-80% filling of the mesopores of the mesoporous alumina with PEI/amine/bicarbonate mixture. The resultant composite sorbents were of a powdery consistency.

Example: Characterization of improved CC>2-philic phases and CO2 sorbents

Chemical characterization was carried out to confirm the properties of the improved CO2- philic phases. Further chemical characterization was carried out to confirm that these CC>2-philic phases were successfully incorporated into the pores of a mesoporous support to create a CO2 sorbent.

FTIR experiments were carried out on sorbents comprised of the improved CC>2-philic phases and mesoporous support to characterize the nature of the sorbents.

N₂ physisorption experiments were carried out on sorbents comprised of the improved CC>2-philic phases and mesoporous support to characterize the porosity and surface area of the sorbents.

TGA burnoff experiments were carried out on sorbents comprised of the improved CO2- philic phases to characterize the total quantity of organic present in the sorbent and to confirm the presence of the phenyl amine containing molecules or bicarbonate salts incorporated into the CC>2-philic phase. Samples were heated under diluted air to 900° C and their mass loss tracked. Total organic content was taken as the mass loss over that temperature interval, after removing the contribution of CO2 and H₂O lost at lower temperatures.

Example: FTIR spectra of sorbent created with mesoporous alumina as the support and an improved CO2-philic phase Figure 4 illustrates FTIR spectra of sorbents created with improved COs-philic phases comprised of PEI and Amine 1 or Amine 6 supported on mesoporous alumina.

Example: N₂ physisorption showing porosity of materials and sorbents

Figure 5 shows the pore size distributions and N₂ physisorption isotherms for a sorbent created with 4,4’-Bis(a,a-dimethylbenzyl)diphenylamine mixed with PEI at 0.1 mol / mol in the alumina support. The data show that the porosity of the alumina is filled in a similar manner with the PEI and additive compared to native PEI. The data show how the mesopore volume of the alumina support is reduced when PEI is impregnated into it, and how it is further reduced when the PEI and additive is impregnated into it due to the added quantity of organic from the modification.

Example: TGA burnoff experiments

Figures 6 and 7 shows the mass loss and heat flow (DSC) curves during exposure of materials to diluted air while ramping the temperature from room temperature to 900° C. The figures show that the native PEI and PEI/Amine sorbents lose substantial mass during the experiment, as the organic fractions of the materials burn off from the oxidative conditions. The sorbents created using phenyl amine additives have mass losses that are greater than the mass ratio of PEI to support and confirm that the amine molecules have been incorporated into the CO₂-philic phase. The DSC traces reveal different oxidative profiles for the materials during the course of the exposure and also confirm that the amine molecules have been incorporated into the CO₂-philic phase.

Figures 8 and 9 shows the mass loss and heat flow (DSC) curves during exposure of materials to diluted air while ramping the temperature from room temperature to 900° C. The figures show that the native PEI and PEI/Bicarbonate sorbents lose substantial mass during the experiment, as the organic fractions of the materials burn off from the oxidative conditions. The sorbents created using bicarbonate additives have mass losses that are greater than the mass ratio of PEI to support and confirm that the bicarbonate molecules have been incorporated into the CO₂-philic phase. The DSC traces reveal different oxidative profiles for the materials during the course of the exposure and also confirm that the bicarbonate molecules have been incorporated into the CO₂-philic phase.

Figure 10 shows the mass loss and heat flow (DSC) curves during exposure of materials to diluted air while ramping the temperature from room temperature to 900° C. The figure shows that the PEI/Amine 1 sorbents lose substantial mass during the experiment, as the organic fractions of the materials burn off from the oxidative conditions. The sorbents created using phenyl amine additives have mass losses that are greater than the mass ratio of PEI to support and confirm that the amine molecules have been incorporated into the COz-philic phase. The DSC traces reveal different oxidative profiles for the materials during the course of the exposure and also confirm that the amine molecules have been incorporated into the CC>2-philic phase. The different porous supports used to create materials have differing mesopore volumes, which explains the different mass ratios of PEI/Amine 1 on the different supports. Supports with large mesopore volume (e.g. SiCh-doped AI2O3 > AI2O3 1 ~ AI2O32 > TiO2) can have a larger degree of CC>2-philic phase incorporated into the pores to achieve the desired 40-80% pore fill.

Example: Testing in CO2 Adsorption Processes

Sorbents created with improved CC>2-phillic phases were tested for CO2 adsorption in a TGA under 400 ppm CO2 at 30° C to simulate the gas contacting step of a Direct Air Capture process. The sorbents were first treated in N₂ at 100°C to desorb any bound H₂O and CO2 before being equilibrated at 30° C under N₂. Then, the gas concentration was switched isothermally to contain 400 ppm CO2 balanced by N2 and the mass change was recorded. Under these moisture free conditions, the mass gain of the material corresponds to the adsorption of CO2 and therefore can be used to measure the total quantity and rate of CO2 adsorption onto the materials.

Various improved sorbents were characterized for CO2 adsorption using this method, and compared to the baseline PEI based sorbent. Sorbents created using PEI and several phenyl amines, PEI and several bicarbonates, and PEI and Amine 1 and Bicarbonate 1 were evaluated relative to the sorbent with PEI alone.

The sorbents were evaluated on two bases, i) CO2 capacity, mmol of CO2 adsorbed per mol of sorbent present, and ii) amine efficiency, mmol of CO₂ adsorbed per mol of N in PEI present in sample. The former unit of performance is useful to show bulk sorbent performance, and the second unit of performance is useful to evaluate the performance of the amine polymer itself and takes into account changes to the bulk composition of the sorbent.

Example: CO2 adsorption uptake capacities at 400 ppm CO2 of PEI and improved CC>2-phi lie phases supported on mesoporous alumina.

Figure 11 shows transient TGA uptake curves under DAC conditions for sorbents created with improved CO2-philic phases utilizing PEI combined with phenyl amine additives, each at 0.1 mol additive / mol PEI, compared to that of unmodified PEI. Each of the sorbents are able to adsorb CO2 at the ultra dilute conditions of 400 ppm, with varying degrees of amine efficiency. The Amine 2, Amine 4, Amine 11, Amine 14, and Amine 15 additives appear to not impact the ability of the material to adsorb CO2 compared to PEI. The Amine 1 and Amine 6 additives reduce the ability to adsorb CO₂ to some extent, followed by Amine 17 showing further reduction, and Amine 9 loosing almost all ability to adsorb CO2. All of the phenyl amine additives either improve or maintain the initial rate of adsorption of CO2 as compared to PEI, with the exception of Amine 9. The initial rate of adsorption follows the trend of PEI + Amine 4 ~ PEI + Amine 1 > PEI + Amine 2 ~ PEI + Amine 6 > PEI + Amine 14 « PEI + Amine 11 > PEI ~ PEI + Amine 15 ~ PEI + Amine 17 > PEI + Amine 9. This indicates that some of the phenyl amine additives can improve the CO2 adsorption rate, thereby allowing sorbents to equilibrate more quickly when adsorbing CO2 from air or other dilute streams.

Figure 12 shows transient TGA uptake curves under DAC conditions for sorbents created with improved CC>2-philic phases utilizing PEI combined with bicarbonate salt additives in addition to a sorbent with bicarbonate salt and phenyl amine additive, each at 0.1 mol additive

1 mol PEI, compared to that of unmodified PEI. Each of the sorbents are able to adsorb CO2 at the ultra dilute conditions of 400 ppm, with varying degrees of amine efficiency. The Bicarbonate

2 additive appears to improve the overall adsorption of CO2 as compared to that of PEI, with Amine 1 + Bicarbonate 1 and Bicarbonate 5 showing comparable CO2 adsorption performance to that of PEI, and Bicarbonate 1 showing reduced CO2 adsorption performance to that of PEI. All of the bicarbonate salt and phenyl amine + bicarbonate salt additives either improve or maintain the initial rate of adsorption of CO2 as compared to PEI. The initial rate of adsorption follows the trend of PEI + Amine 1 + Bicarbonate 1 > PEI + Bicarbonate 2 > PEI « PEI + Bicarbonate 5 ~ PEI + Bicarbonate 1. This indicates that some of the bicarbonate salt and phenyl amine combined with bicarbonate salt additives can improve the CO2 adsorption rate, thereby allowing sorbents to equilibrate more quickly when adsorbing CO₂ from air or other dilute streams.

Example: Testing of Oxidative Stability

The oxidative stability of materials can be probed in several ways In this study, the oxidative stability of the sorbents was evaluated by tracking the heat flow evolved from the materials using a DSC during exposure to isothermal oxidative conditions. Here, the sorbents were first treated in inert gas at 100° C to desorb any bound H₂O and CO2 before being equilibrated at either 125, 137.5 or 150° C under inert gas for 60 minutes. The gas was then isothermally switched to a 17% O2 mixture, or a mixture of 17% O₂ and 20% CO₂, and held until the reaction finished. This isothermal, oxidative environment was maintained for a specific amount of time to measure the heat flow and mass loss. To prevent any further oxidation, the sample was then cooled under N₂ to room temperature. During these experiments, for each oxidative condition, the DSC measures the incremental heat flux, which increases, levels out, and then decreases to zero. The oxidation was considered complete when the integrated heat flow over 10 min changed less than ±0.01% of the total integrated heat. To determine the extent of oxidation as a function of time, DSC data were converted from the base unit of mW/mg sorbent to W/gPEI using the PEI loading measured by TGA burnoff. DSC data were corrected for drift by applying an offset, determined by the heat flow value when the DSC curve approached a horizontal line. The total heat evolved was calculated by integrating heat flow over time. The extent of oxidation from DSC was calculated by dividing the integral heat flow curve by the total heat evolved. This method has been previously calibrated with the loss in amine efficiency as being a method of tracking the chemical reaction rate of oxidative degradation in-situ, and is shown in Figure 13. Further details on this method and its validation are discussed in the following papers: Nezam et al, ACS Sustainable Chem. Eng., 2021 , 9, 8477-8486, and Racicot et al, J. Phys. Chem. C, 2022, 126, 8807-8816, which is incorporated herein by reference.

Evaluating the oxidative stability of materials in environments that contain oxygen and CO₂ is useful due to the fact that during regeneration processes, desorbed CO₂ is present at different concentrations in addition to oxygen at elevated temperatures, and can impact the stability of the material. Separately, evaluating the oxidative stability of materials with oxygen only (air) is a useful way to evaluate the shelf life of a material when it is stored at ambient conditions.

Figure 14 shows oxidation curves in the presence of CO2 for CO2 sorbents created with a variety of phenyl amines, labeled by their reference in Figure 3, mixed with PEI at a ratio of 0.1 mol additive I mol PEI, and supported in mesoporous alumina. The figure shows three general categories of behavior; some amines accelerate the oxidation of PEI, some amines do not greatly change the oxidation rate of PEI, and some amines slow the oxidation rate of PEI. In particular, Amine 1 , Amine 3, Amine 6, Amine 7, Amine 9, Amine 10, Amine 14, Amine 16, and Amine 17 slow the oxidation rate of PEI, while Amine 2 accelerates the oxidation rate of PEI, and Amine 15 has a comparable rate of oxidation to that of PEI. The differences between the extent of oxidation observed for the different phenyl amine additives in Figure 14 suggest that many phenyl amines are effective antioxidants for the conditions related to regeneration during CO2 capture processes, but to varying extents. Figure 15 shows oxidation curves in the presence of air only for CO2 sorbents created with a variety of phenyl amines, labeled by their reference in Figure 3, mixed with PEI at a ratio of 0.1 mol additive / mol PEI, and supported in mesoporous alumina. The figure shows three general categories of behavior; some amines accelerate the oxidation of PEI, some amines do not greatly change the oxidation rate of PEI, and some amines slow the oxidation rate of PEI. In particular, Amine 1 , Amine 6, Amine 11 , and Amine 14 slow the oxidation rate of PEI, while Amine 3, Amine 5, Amine 7, Amine 8, Amine 9, Amine 10, and Amine 12 accelerates the oxidation rate of PEI. The differences between the extent of oxidation observed for the different phenyl amine additives in Figure 15 suggest that not all phenyl amines are effective antioxidants for the conditions related to storage of CO2 capture materials.

Figure 16 shows oxidation curves in the presence of CO2 for a CO2 sorbent created with Bicarbonate 1 , labeled by their reference in Figure 3, mixed with PEI at a ratio of 0.1 mol additive I mol PEI, and supported in mesoporous alumina as compared to unmodified PEI. The figure shows that the bicarbonate salt additive has a comparable rate of oxidation to that of PEI for the conditions related to regeneration during CO2 capture processes.

Figure 17 shows oxidation curves in the presence of air only for CO2 sorbents created with a variety of bicarbonate salts, labeled by their reference in Figure 3, mixed with PEI at a ratio of 0.1 mol additive / mol PEI, and supported in mesoporous alumina as compared to unmodified PEI. The figure shows three general categories of behavior; some bicarbonates accelerate the oxidation of PEI, some bicarbonates do not greatly change the oxidation rate of PEI, and some bicarbonates slow the oxidation rate of PEI. In particular, Bicarbonate 1 and Bicarbonate 5 slow the oxidation rate of PEI, while Bicarbonate 3 and Bicarbonate 4 accelerate the oxidation rate of PEI. The differences between the extent of oxidation observed for the different bicarbonate salt additives in Figure 17 suggest that not all bicarbonates are effective antioxidants for the conditions related to storage of CO₂ capture materials.

Figure 18 shows oxidation curves in the presence of air only for CO2 sorbents created with PEI, a mixture of PEI and Bicarbonate 1 , a mixture of PEI and Amine 1 , and a tertiary mixture of PEI, Amine 1, and Bicarbonate 1 , all at a ratio of 0.1 mol additive / mol PEI, and supported in mesoporous alumina. The binary additive mixture, forming a tertiary CC>2-phi lie phase mixture, showed further improvement on the oxidation rate in comparison to PEI + Amine 1 or PEI + Bicarbonate 1 alone. This indicates that the additives are not competing with one and other, but rather show synergistic behavior and can further improve the oxidation rate. Overall, this formulation nearly doubled the time taken for the PEI to reach full oxidation. Figures 14-18 illustrate that phenyl amines, bicarbonate salts, and combinations of phenyl amines and bicarbonate salts are effective antioxidants in conditions when CO2 is present as well as in conditions with air only. It also can be seen that different phenyl amines and bicarbonate salts are advantageous for certain applications over others, in this case different phenyl amines and bicarbonate salts may be useful in reducing oxidative degradation in certain CO2 capture processes that have high concentrations of CO2, as well as phenyl amines and bicarbonate salts that are useful in reducing oxidative degradation during material storage in ambient conditions. In this regard, materials of the present disclosure can be tuned based on the process in which they are deployed.

Figure 19 shows oxidation curves in the presence of air only for CO2 sorbents created with PEI and a mixture of PEI and Amine 1 at varying additive mol ratios, supported in mesoporous alumina. An improvement in the oxidation rate can be seen as the loading of Amine 1 increases from 0.025 mol amine I mol PEI up to 0.1 mol amine / mol PEI, after which it appears to plateau. This indicates that the additive ratio can be optimized for tuning the rate of oxidation of CO2 sorbents.

Figure 20 shows oxidation curves in the presence of air only for CO2 sorbents created with PEI and a mixture of PEI + Amine 1 at 0.1 mol amine / mol PEI, supported in different mesoporous supports (two commercial aluminas, a commercial titania, and a commercial silica- doped alumina). It can be seen that improvements in the rate of oxidation are observed with the addition of Amine 1 across all supports. It also can be seen that the rate of oxidation is impacted by the choice of support. However, the phenyl amine additive consistently improves the oxidative stability for a given support compared to the unmodified PEI sorbent.

Example: Preparation of honeycomb monolith with improved CC>2-philic phase containing polyethylenimine (PEI) and 4,4’-Bis (a,a-dimethybenzyl) diphenylamine

Extruded titania monoliths were used for the preparation of honeycomb monolith sorbents with an improved CC>2-philic phase. For the purpose of creating test samples, honeycomb monolith cores were used. The cores were cylindrical in shape, with a diameter of 1 inch and a length of 6 inches. The honeycomb monoliths have square shaped channels, with a cell density of 170 cpsi. For the preparation of oxidation-resistant sorbent honeycomb monoliths, phenyl amine containing PEI solution was prepared: Methanol was used to dissolve the PEI and toluene was used to dissolve the phenyl amine in a ratio corresponding to 0.1 mol amine per mol of N present in PEI. Once dissolved, the solutions were mixed and allowed to stir at room temperature for a minimum of 1 hour prior to impregnation in the honeycomb monolith. The solution was carefully added to a container containing the honeycomb monolith, filling from bottom to top until the honeycomb monolith was completely immersed. The honeycomb monolith was immersed in the solution for 1 hour to allow the filling of the pore network of the porous media. Following this solution immersion period, the solvent was removed by first clearing the channels using pressurized N₂, followed by drying at 100°C under vacuum for 10 hours.

Honeycomb monoliths containing PEI with and without Amine 1 were prepared with a common pore filling. Table 3 shows the bulk properties of both sorbent honeycomb monoliths. The amine efficiency from a 900s adsorption of CO2 from ambient air is also shown according to the testing procedure given below.

Table 3: Bulk properties of sorbent honeycomb monoliths prepared and tested

Example: Testing of improved honeycomb monolith for DAC

The honeycomb monolith cores prepared and described in Table 3 were tested for their ability to capture CO2 from actual air. The cores were tested in an experimental device able to control the flow of air through the honeycomb monolith channels following a regeneration to remove adsorbed CO2 and water. A CO2 detector downstream of the honeycomb monolith recorded the concentration of CO2 in the effluent gas stream and was used to determine CO2 adsorption. Air was delivered to the honeycomb monolith at an approach velocity of 5 m/s to the honeycomb monolith face. Data are shown for 900s, or 15 minutes of adsorption.

Figure 21 shows uptake curves for the two honeycomb monolith sorbents, with the amount of CO2 adsorbed expressed as the amine efficiency (mol CO2 captured I mol N in PEI). The data show that the material with an improved CC>2-philic phase increased the rate of capture relative to the quantity of amines present in the material. This finding shows that the improved CC>2-philic phase does not diminish the intrinsic ability for PEI to adsorb CO2, and that it may offer advantages in the rate of adsorption of CO2 in addition to improving the stability of the material.

Example: Testing of improved honeycomb monoliths for DAC in a steam regeneration process Honeycomb monolith cores prepared in the same method as described in the previous example were tested for their ability to capture CO2 from ambient air and desorb CO2 via a regeneration process that includes of contacting the honeycomb monolith with steam at a pressure of 1-2 bara. The CO₂ loading post CO₂ adsorption (PA) and post CO₂ desorption via regeneration with steam (PR) were evaluated across multiple experiments that had different cycle conditions (temperature, humidity, steam pressure, etc.) that were applied to both a honeycomb monolith with PEI only, and a honeycomb monolith with PEI + Amine 1. The results are presented in Table 4. The CO2 swing capacity is defined as: (PA CO2 Loading - PR CO2 Loading) and represents the amount of CO2 that is collected in an adsorption/desorption cycle. A sorbent with a high CO₂ swing is advantageous because it means that a larger amount of CO₂ can be collected per process cycle. Comparing PA and PR loadings with the CO2 swing capacity for honeycomb sorbents with PEI and PEI + Amine 1, it can be seen that under the same conditions, PEI + Amine 1 sorbents more readily release CO2 during regeneration as compared to PEI and result in larger CO2 swing capacities.

Table 4: Post CO2 adsorption (PA), post CO2 desorption with steam (PR), and CO2 swing capacity expressed as cc CO2/ cc honeycomb monolith volume for honeycomb sorbents with PEI and PEI + Amine 1 tested under different process cycle conditions.

Example: Preparation of honeycomb monoliths with improved CC philic phase containing polyethylenimine (PEI) and: 4,4’-Bis (a,a-dimethybenzyl) diphenylamine, Bis(4-tert- butylphenyl)amine, 4,4’-Dimethyldiphenylamine, or sodium bicarbonate

For the preparation of oxidation-resistant sorbent honeycomb monoliths, honeycomb monoliths having a honeycomb channel structure, comprised of porous titania were utilized. The following PEI + additive solutions were prepared to create the honeycomb monoliths with improved CO2-philic phases:

PEI + Amine 1 : a 4,4’-Bis (a,a-dimethybenzyl) diphenylamine and PEI solution was prepared: methanol was used to dissolve the PEI and the amine was added to toluene in a ratio corresponding to 0.1 mol amine per mol of N present in PEI. The two mixtures were combined to form a homogenous solution. The PEI/amine mixture was allowed to stir at room temperature for approximately 1 hour prior to impregnation in the honeycomb monolith.

PEI + Amine 6: a Bis(4-tert-butylphenyl)amine and PEI solution was prepared: methanol was used to dissolve the PEI and the amine was added to toluene in a ratio corresponding to 0.1 mol amine per mol of N present in PEI. The two mixtures were combined to form a homogenous solution. The PEI/amine mixture was allowed to stir at room temperature for approximately 1 hour prior to impregnation in the honeycomb monolith.

PEI + Amine 11 : a 4,4’-Dimethyldiphenylamine and PEI solution was prepared: the PEI was dissolved in a solution of methanol, after which the amine was added in a ratio corresponding to 0.1 mol amine per mol of N present in PEI and stirred until homogenous. The PEI/amine mixture was allowed to stir at room temperature for approximately 1 hour prior to impregnation in the honeycomb monolith.

PEI + Bicarbonate 1 : a sodium bicarbonate and PEI solution was prepared: water was used to dissolve the PEI and the bicarbonate was added in a ratio corresponding to 0.1 mol bicarbonate per mol of N present in PEI and stirred until fully homogenous. The PEI/bicarbonate mixture was allowed to stir at room temperature for approximately 1 hour prior to impregnation in the honeycomb monolith.

For each of the four PEI/additive mixtures prepared, the solution was then poured over a separate honeycomb monolith in a controlled manner. The honeycomb monoliths were immersed in the solution for 1.5 hours to allow the filling of the pore network of the porous media. When the pores were completely occupied with the PEI/additive + solvent solution, the solvent was removed. To remove the excess of solvent, the honeycomb monolith channels were cleared out using an air knife and the honeycomb monoliths were then dried. The drying step is performed at 100 °C under vacuum for 10 hours. These drying conditions remove the solvent and eliminate oxygen from the environment to prevent oxidation at elevated temperatures. The product honeycomb monolith properties are provided in Table 5. Figure 22 shows the TGA burnoff for some of the prepared honeycomb monoliths with PEI and additives. Table 5: 3ulk properties of honeycomb monolith sorbents with amine or bicarbonate additives

It should be noted that ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of “about 0.1% to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 wt% to about 5 wt%, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range. In an aspect, the term “about” can include traditional rounding according to significant figures of the numerical value. In addition, the phrase “about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”.

Many variations and modifications may be made to the above-described aspects. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

What is claimed is:

1. A sorbent comprising: a CC>2-philic phase and a support, wherein the CC>2-philic phase includes CO2 binding molecules moieties and phenyl amine containing molecules, wherein the CO2 binding molecules include CO2 binding moieties.

2. The sorbent of claim 1 , wherein the CO2- phi I ic phase is an amine.

3. The sorbent of claim 2, wherein the amine is an amine polymer.

4. The sorbent of claim 3, where the amine polymer is branched, hyperbranched, dendritic, or linear.

5. The sorbent of claim 3, wherein the amine polymer is one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene- divinylbenzene polymer functionalized with amine, or other amine polymers.

6. The sorbent of claim 1, wherein the CC>2-philic phase is homogeneous.

7. The sorbent of claim 1 , wherein the CC philic phase is heterogeneous

8. The sorbent of claim 1 , wherein the phenyl amine containing molecules is selected from diphenylamines and substituted diphenylamines.

9. The sorbent of claim 8, wherein the phenyl amine containing molecules is selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’- diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, N,N’-di-sec-butyl-p-phenylenediamine, bis(4-tert-butylphenyl)amine, bis(4-nitrophenyl)amine , 4-isopropylaminodiphenylamine, 4,4'- bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 4,4’- dimethyldiphenylamine, 3,5-di-tert-butylaniline, 2,2'-dinapthylamine, 4,4’- dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)- pyridone.

10. The sorbent of claim 8, wherein the phenyl amine containing molecules is selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’- diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, bis(4-tert-butylphenyl)amine, bis(4- nitrophenyl)amine , 4,4'-bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1 ,4- phenylenediamine, 4,4’-dimethyldiphenylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)-pyridone.

11. The sorbent of claim 8, wherein the phenyl amine containing molecules is selected from one or a combination of 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, bis(4-tert- butylphenyl)amine, and 4,4’-dimethyldiphenylamine.

12. The sorbent of claim 2, wherein the amine is physically impregnated into pores of the support.

13. The sorbent of claim 2, wherein the amine is physically impregnated onto the surface of the support.

14. The sorbent of claim 2, wherein the amine is covalently bonded to the surface of the support.

15. The sorbent of claim 1 , wherein the support is ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymers of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

16. A sorbent comprising: a CC>2-philic phase and a support, wherein the CC>2-philic phase includes CO2 binding molecules moieties and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties.

17. The sorbent of claim 16, wherein the CC philic phase is an amine.

18. The sorbent of claim 17, wherein the amine is an amine polymer.

19. The sorbent of claim 18, where the amine polymer is branched, hyperbranched, dendritic, or linear.

20. The sorbent of claim 18, wherein the amine polymer is one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene- divinylbenzene polymer functionalized with amine, or other amine polymers.

21. The sorbent of claim 16, wherein the CC philic phase homogeneous.

22. The sorbent of claim 16, wherein the CC>2-philic phase heterogeneous

23. The sorbent of claim 16, wherein the bicarbonate salt is selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, aminoguanidine bicarbonate, cesium bicarbonate, choline bicarbonate, tetraalkylammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof.

24. The sorbent of claim 17, wherein the amine is physically impregnated into pores of the support.

25. The sorbent of claim 17, wherein the amine is physically impregnated onto the surface of the support.

26. The sorbent of claim 17, wherein the amine is covalently bonded to the surface of the support.

27. The sorbent of claim 16, wherein the support is ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymers of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

28. A sorbent comprising: a CC>2-philic phase and a support, wherein the CC>2-philic phase includes CO2 binding molecules moieties and both phenyl amine containing molecules and bicarbonate salts, wherein the CO2 binding molecules include CO2 binding moieties.

29. The sorbent of claim 28, wherein the CC philic phase is an amine.

30. The sorbent of claim 29, wherein the amine is an amine polymer.

31. The sorbent of claim 30, where the amine polymer is branched, hyperbranched, dendritic, or linear.

32. The sorbent of claim 30, wherein the amine polymer is one of polyethylenimine, polypropylenimine, polyallylamine, polyvinylamine, polyglycidylamine, or polystyrene- divinylbenzene polymer functionalized with amine, or other amine polymers.

33. The sorbent of claim 28, wherein the COz-philic phase is homogeneous.

34. The sorbent of claim 28, wherein the COz-philic phase is heterogeneous

35. The sorbent of claim 28, wherein the phenyl amine containing molecules is selected from diphenylamines and substituted diphenylamines.

36. The sorbent of claim 28, wherein the phenyl amine containing molecules is selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’- diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, N,N’-di-sec-butyl-p-phenylenediamine, bis(4-tert-butylphenyl)amine, bis(4-nitrophenyl)amine , 4-isopropylaminodiphenylamine, 4,4'- bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 4,4’- dimethyldiphenylamine, 3,5-di-tert-butylaniline, 2,2'-dinapthylamine, 4,4’- dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)- pyridone.

37. The sorbent of claim 28, wherein the phenyl amine containing molecules is selected from one or a combination of: 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, diphenylamine, N,N’- diphenyl-p-phenylenediamine, N’N’-diphenylbenzidine, bis(4-tert-butylphenyl)amine, bis(4- nitrophenyl)amine , 4,4'-bis(dimethylamino) diphenylamine, N-(1 ,3-Dimethylbutyl)-N'-phenyl-1 ,4- phenylenediamine, 4,4’-dimethyldiphenylamine, 4,4’-dimethoxydiphenylamine, 2,2-pyridylamine, di-(2-picolyl)amine, and 2,6-bis(2-pyridyl)-4(1 H)-pyridone.

38. The sorbent of claim 28, wherein the phenyl amine containing molecules is selected from one or a combination of 4,4’-bis(a,a-dimethylbenzyl) diphenylamine, bis(4-tert- butylphenyl)amine, and 4,4’-dimethyldiphenylamine.

39. The sorbent of claim 28, wherein the bicarbonate salt is selected from sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, aminoguanidine bicarbonate, cesium bicarbonate, choline bicarbonate, tetraalkylammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof.

40. The sorbent of claim 29, wherein the amine is physically impregnated into pores of the support.

41. The sorbent of claim 29, wherein the amine is physically impregnated onto the surface of the support.

42. The sorbent of claim 29, wherein the amine is covalently bonded to the surface of the support.

43. The sorbent of claim 28, wherein the support is ceramic, metal, metal oxide, plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covenant organic framework (COF), a polymers of intrinsic microporosity (PIM), a polymer, a fibrous cellulose, fiberglass, or boron-nitride fiber.

44. A contactor, comprising a structure and the sorbent of any one of claims 1 to 43.

45. The contactor of claim 44, wherein the structure is selected from a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, or a combination of these.

46. A system for capturing CO2 from a gas, optionally the gas is ambient air, comprising: a first device configured to introduce the gas to the sorbent or contactor of any one of claims 1 to 45 to bind CO2 to the sorbent; a second device configured to heat the sorbent containing bound CO2 to at least a first temperature to release the CO2; and a third device configured to collect the released CO2.

47. The system of claim 46, wherein after being heated the sorbent is regenerated so it able to absorb CO2 from the gas.

48. The system of claim 46, wherein the sorbent is in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof.

49. The system of claim 48, wherein the honeycomb has an open face area of between 0.3- 0.95.

50. The system of claim 46, wherein the gas approaches the honeycomb at a velocity of between 0.25-10 m/s.

51. The system of claim 46, wherein the system is configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO2.

52. A method of capturing CO2 from gas optionally the gas is ambient air comprising: introducing the ambient air to the sorbent of any one of claims 1 to 45 to bind CO2 to the sorbent; heating the sorbent to at least a first temperature to controllably release the CO2; and collecting the CO2 in a CO2 collection device.

53. The method of claim 52, wherein heating the sorbent regenerates the sorbent so it is able to absorb CO2 from ambient air.

54. The method of claim 52, wherein the sorbent is heated by contacting it with steam.

55. The method of claim 52, wherein the method is configured to operate to remove CO2 from ambient air, where the ambient air has a low concentration of CO2.

56. The method of claim 52, wherein the sorbent is in the form of a honeycomb, a laminate sheet, a foam, fibers, a minimal surface solid, powder trays, pellets, a combination thereof.

57. A system for implement the method of any one of claim 52 to 56.