Substituted epoxide-modified adsorbents, systems including

Abstract

The present disclosure provides substituted epoxide modified adsorbents and contactors, methods of capturing CO2 using the adsorbents and contactors, structures including the adsorbents, and systems and devices for capturing CO2 using the adsorbents and contactors. The present disclosure provides adsorbents and contactors that may include a CO2-philic phase and a carrier. The CO2-philic phase may include a modified amine polymer that is a reaction product of an amine and a substituted epoxide.

Description

[0001] Priority claim of related application

[0002] This application claims priority to co-pending U.S. Provisional Application No. 63 / 364,308, filed on May 6, 2022, entitled “SORBENTS, SYSTEMS INCLUDING SORBENTS, AND METHODS USING THE SORBENTS”, which is hereby fully incorporated by reference. In addition, this application claims priority to co-pending U.S. Provisional Application No. 63 / 431,512, filed on December 9, 2022, entitled “SORBENTS, SYSTEMS INCLUDING SORBENTS, AND METHODS USING THE SORBENTS”, which is hereby fully incorporated by reference. Background Art

[0003] 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, electricity, industry, and agriculture. In particular, burning fossil fuels, solid waste, and trees, as well as manufacturing cement and other materials, all produce CO2 emissions. One way to reduce the amount of CO2 in the atmosphere is to capture CO2 using materials that have an affinity for CO2. Materials that can efficiently capture CO2 are needed. Summary of the invention

[0004] The present disclosure provides substituted epoxide-modified adsorbents and contactors, methods of capturing CO2 using the adsorbents and contactors, structures including the adsorbents, and systems and apparatuses for capturing CO2 using the adsorbents and contactors.

[0005] One aspect of the present disclosure provides an adsorbent comprising: a CO2-philic phase and a support, wherein the CO2-philic phase comprises a reaction product of a substituted epoxide and an amine.

[0006] One aspect of the present disclosure provides a contactor comprising a structure and an adsorbent as described above and herein.

[0007] One aspect of the present disclosure provides a system for capturing CO2 from a gas, optionally, the gas is ambient air, the system comprising: a first device configured to introduce the gas into an adsorbent or contactor as described above, and bind the CO2 to the adsorbent therein; a second device configured to heat the adsorbent containing the bound CO2 to at least a first temperature to release the CO2; and a third device configured to collect the released CO2.

[0008] One aspect of the present disclosure provides a method for capturing CO2 from a gas, optionally, the gas is ambient air, the method comprising: introducing ambient air into an adsorbent as described above to bind CO2 to the adsorbent; heating the adsorbent to at least a first temperature to controllably release CO2, and collecting CO2 in a CO2 collection device.

[0009] One aspect of the present disclosure provides a system for implementing the method described above and herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other aspects of the present disclosure will be more readily understood when the detailed description of various embodiments of the present disclosure described below is read in conjunction with the accompanying drawings.

[0011] Figure 1A Schematic showing how the amine moiety binds CO2 to form carbamate. Figure 1B Schematic diagram of an adsorbent system consisting of a support and a CO2-philic phase. The support and the CO2-philic phase together constitute the adsorbent.

[0012] Figure 2 Schematic diagram of a honeycomb monolithic contactor consisting of a substrate and an adsorbent coating.

[0013] Figure 3 Substituted epoxides evaluated as polyethyleneimine (PEI) modifiers are shown.

[0014] Figure 4 The mass loss curves of adsorbents produced from modified CO2-philic phases containing PEI reacted with substituted epoxides and unmodified PEI during exposure to dilute air as the temperature is increased from room temperature to 900°C are shown.

[0015] Figure 5 Shown are heat flow (DSC) curves of adsorbents produced from modified CO2-philic phases containing PEI reacted with substituted epoxides and unmodified PEI during exposure to dilute air as the temperature is increased from room temperature to 900°C.

[0016] Figure 6 The instantaneous mass change curve of TGA CO absorption experiment carried out at 400ppm CO2 (DAC conditions) using improved adsorbents containing PEI reacted with substituted epoxides is shown; the molar ratio of substituted epoxide to primary N in PEI in each adsorbent is 0.5 mol / mol, and all adsorbents are supported on mesoporous alumina. The data of adsorbents using PEI are also shown for reference. The data are reported as amine efficiency (mol CO2 in PEI / mol N present in the sample).

[0017] Figures 7A-7DThe degree of oxidation of PEI as a function of time is shown as measured by differential scanning calorimetry (solid line, DSC) as described herein and discussed in reference publications and by ( Fig. 7A )5%, ( Figure 7B )17% and ( Figure 7C ) The loss of amine efficiency at 30% O2 concentration (data point, AE) was determined; ( Fig.7D ) Oxidation degree of different PEI pore fillers. Figure from Nezam et al., ACS Sustainable Chem. Eng., 2021, 9, 8477-8486.

[0018] Figure 8 : Transient oxidation curves of PEI and PEI reacted with substituted epoxides, tested at 137.5 °C in 17% O2, balance N2, all adsorbents were in mesoporous alumina, the substituted epoxide ratio was 0.5 mol substituted epoxide / mol primary nitrogen in PEI.

[0019] Fig. 9 Exemplary structures of modified amines on modified amine polymers are shown.

[0020] Fig.10 An exemplary chemical structure of a 1-amino-2-ol group that reacts with a primary amine to form a secondary amine is shown. DETAILED DESCRIPTION

[0021] Embodiments of the present disclosure provide substituted epoxide-modified adsorbents (also referred to herein as "adsorbents" or "adsorbents") and contactors, methods of capturing CO2 using adsorbents and contactors, structures including adsorbents, and systems and devices for capturing CO2 using adsorbents and contactors. The methods, systems, and adsorbents of the present disclosure may be superior to current technologies because they are relatively more robust and reduce the cost of capturing CO2, particularly from ambient air. In one aspect, the present disclosure provides adsorbents and contactors having an improved CO2-philic phase that has greater resistance to oxidation. In one aspect, the CO2-philic phase is produced by modifying an amine with a reactive molecule to form a modified amine.

[0022] Before describing the present disclosure in more detail, it should be understood that the present disclosure is not limited to the particular embodiments described, and therefore may of course vary. It should also be understood that the terminology used herein is only for the purpose of describing particular embodiments and is not intended to be limiting, as the scope of the present disclosure will be limited only by the appended claims.

[0023] Where a numerical range is provided, it is understood that, unless the context clearly dictates otherwise, every intervening value between the upper and lower limits of the range, to one-tenth of the unit of the lower limit, and any other specified value or intervening value within the specified range, is included in the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also included in the disclosure, subject to any specific exclusions in the specified range. When a specified range includes one or two limits, ranges excluding either or both of the included limits are also included in the disclosure.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present 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, preferred methods and materials are described herein.

[0025] As will be apparent to those skilled in the art upon reading this disclosure, each individual embodiment described and illustrated herein has discrete components and features that may be readily separated or combined with the features of any other several embodiments without departing from the scope or spirit of the disclosure. Any described method may be performed in the order of events described or in any other order that is logically possible.

[0026] Unless otherwise indicated, embodiments of the present disclosure will employ techniques of chemistry, materials science, mechanical engineering, and the like, which are within the skill of the art.

[0027] The following examples are presented to provide a person of ordinary skill in the art with a complete disclosure and description of how to implement the methods disclosed and claimed herein and use the detectors disclosed and claimed herein. Efforts have been made to ensure the accuracy of numbers (e.g., amounts, temperatures, etc.), but some errors and deviations should be considered. Unless otherwise indicated, parts are parts by volume, temperatures are in ° C, and pressures are at or near atmospheric pressure. Standard temperature and pressure are defined as 20 ° C and 1 atmosphere.

[0028] Before describing the embodiments of the present disclosure in detail, it should be understood that, unless otherwise stated, the present disclosure is not limited to specific materials, reagents, reaction materials, manufacturing processes, etc., as they may vary. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting. In the present disclosure, different step orders may also be performed where logically possible.

[0029] It must be noted that, as used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a compound" includes a plurality of compounds. In this specification and the claims that follow, reference will be made to a number of terms, which, unless otherwise apparent, will be defined as having the following meanings.

[0030] definition:

[0031] "Chemically feasible" refers to bonding arrangements or compounds that do not violate the commonly understood rules of organic structure. The structures disclosed herein are intended to include only "chemically feasible" structures in all of their embodiments, and any listed chemically infeasible structures, such as those shown with variable atoms or groups, are not intended to be disclosed or claimed herein. However, if a bond appears to be expected and a group, such as a hydrogen, needs to be removed from a carbon, one skilled in the art will understand that a hydrogen can be removed to form the desired bond.

[0032] The term "substituted" refers to any one or more hydrogen atoms on a designated atom (e.g., a carbon atom) that can be replaced by a group selected from a designated group (e.g., halogen, hydroxyl, alkyl, etc.), provided that the normal valence of the designated atom is not exceeded. As used herein, the term "optionally substituted" generally refers to 0 to 4 substituents, wherein the substituents are independently selected. Each independently selected substituent may be the same or different from other substituents. For example, a substituent (e.g., R type group) of a structural formula may, alternatively, be independently selected H, halogen, hydroxyl, acyl, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclic radical, aryl, heteroaryl, alkoxy, amino, amide, thiol, sulfone, sulfoxide, oxo, oxy, nitro, carbonyl, carboxyl, amino acid side chain, amino acid, etc. (e.g., 1 to 4 times). In one embodiment, substitution includes substitution with halogen. Each group (e.g., alkyl, allyl, phenyl, phenol, benzyl, nitroimidazole, aryl, heteroaryl, alkoxy, alkylamino) may be substituted or unsubstituted.

[0033] As used herein, a "derivative" of a compound refers to a compound that can be produced in one or more steps from another compound of similar structure, such as by replacing H with an alkyl, acyl, amino, or the like.

[0034] As used herein, "alkyl" or "alkyl group" refers to a saturated aliphatic hydrocarbon, which may be linear or branched, having 1 to 40, 1 to 20, 1 to 10, or 1 to 5 carbon atoms, wherein specified carbon atom ranges individually include each intervening integer, as well as subranges. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, and sec-pentyl. References to "alkyl" or "alkyl group" include unsubstituted and substituted forms of the hydrocarbon moiety.

[0035] As used herein, "halo", "halogen", "halide" or "halogen radical" refers to fluorine, chlorine, bromine, iodine and astatine and radicals thereof. In addition, when used in compound words, for example, "alkylhalide" refers to an alkyl or alkenyl group in which one or more hydrogens are replaced by a halogen radical.

[0036] As used herein, an "allyl" group refers to -CH2-HC=CH2.

[0037] As used herein, a "phenyl" group refers to a 6-carbon aromatic ring (C6H5-) which can be bonded as a functional group through the carbon after losing a hydrogen atom in the compound.

[0038] As used herein, a "phenol" group refers to a 6-carbon aromatic ring (C6H5OH-) which can be bonded via the carbon in the compound after losing a hydrogen atom as a functional group.

[0039] As used herein, a "benzyl" group refers to a 6-carbon aromatic ring in which one of the hydrogens on the ring is replaced by -C(H2)-, and the -C(H2)- can be bonded through a carbon in the compound as a functional group (ring-C(H2)-X).

[0040] As used herein, a "nitroimidazole" group refers to (O2NC3H2N2H) or It may be bonded via nitrogen to replace a hydrogen in the heterocyclic ring.

[0041] As used herein, an "alkylamino" group refers to (R1-NH2 or R1-NH-R2). Alternatively, each R may be -(CH x ) y or H, which may be bonded through carbon to replace hydrogen, wherein x may be 2 or 3 and y may be 1 to 20.

[0042] As used herein, "aryl" refers to a C5-C 10-membered aromatic, heterocyclic, fused aromatic, fused heterocyclic, biaromatic or biheterocyclic ring systems. As used herein, the broad definition of "aryl" includes 5-, 6-, 7-, 8-, 9- and 10-membered monocyclic aromatic groups, which may include 0 to 4 heteroatoms, such as benzene, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, etc.

[0043] Those aryl groups that contain heteroatoms in the ring structure may also be referred to as "heteroaryl" or "heteroaromatic".

[0044] "Heteroaryl" refers to any stable 5, 6, 7, 8, 9, 10, 11 or 12-membered (unless the number of elements is otherwise listed), monocyclic, bicyclic or tricyclic heterocyclic ring, which is aromatic and consists of carbon atoms and 1, 2, 3 or 4 heteroatoms independently selected from N, O and S. If heteroaryl is defined by the number of carbon atoms, then 1, 2, 3 or 4 carbon atoms listed are replaced by heteroatoms. If heteroaryl is bicyclic or tricyclic, then at least one of the two or three rings must contain heteroatoms, although two or all three rings may each contain one or more heteroatoms. If heteroaryl is bicyclic or tricyclic, then only one ring must be aromatic. The N group can be N, NH or N-substituents, depending on the selected ring and whether substituents are listed. Nitrogen and sulfur heteroatoms can be optionally oxidized (e.g., S, S(O), S(O)2 and NO). The heteroaryl ring can be attached to its side group at any heteroatom or carbon atom to form a stable structure. The heteroaryl rings described herein may be substituted on carbon or on a nitrogen atom if the resulting compound is stable.

[0045] The term "heteroatom" refers to, for example, oxygen, sulfur, nitrogen, phosphorus or silicon (including any oxidized form of nitrogen, sulfur, phosphorus or silicon; the quaternized form of any basic nitrogen; or a substitutable nitrogen of a heterocycle).

[0046] The term "alkoxy" represents an alkyl group as defined above, having a specified number of carbon atoms connected by an oxygen bridge. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy and sec-pentoxy. The term "lower alkoxy" refers to an alkoxy group having less than 10 carbon atoms.

[0047] discuss

[0048] The present disclosure provides substituted epoxide-modified adsorbents (also referred to herein as "adsorbents" or "adsorbents") and contactors, methods of using the adsorbents and contactors to capture CO2, structures including the adsorbents, and systems and apparatuses for using the adsorbents and contactors to capture CO2. The present disclosure relates to various types of adsorbents and structures that will be described below and herein.

[0049] In one aspect, the present disclosure provides an adsorbent and a contactor comprising a CO2-philic phase and a support, wherein the CO2-philic phase comprises a modified amine polymer, which is a reaction product of an amine and a substituted epoxide. The reaction product is also described herein. The CO2-philic phase comprises a CO2-binding molecule. The CO2-binding molecule comprises a CO2-binding portion. In one aspect, the modified amine polymer maintains a high CO2 capacity relative to an unmodified amine polymer. In one aspect, an adsorbent with a modified amine polymer loses less ability to capture CO2 after oxidative exposure than an adsorbent produced with an unmodified amine polymer, thereby producing an improved CO2-philic phase with a longer commercial life relative to a CO2-philic phase without an epoxide.

[0050] A structured support, also called a shaped support or structure, refers to a support that has been shaped into a structure, wherein the structure is solid under standard conditions. A support may also be unstructured, having a powdery consistency under standard conditions. When a support is mentioned without mentioning structure, shaping or being shaped or structured, it may refer to a structured or unstructured support.

[0051] The structured support may take the form of a homogeneous solid (ie consisting essentially of the support but also comprising components which allow it to remain a stable body under standard conditions) or as a coating on a substrate whereby the substrate has a different composition than the coating and provides mechanical stability to the coating.

[0052] In the process of removing CO2 from a gas stream such as ambient air, it is useful to utilize a structured support having a CO2-philic phase as a contactor. The contactor provides a geometry for the CO2-philic phase so that considerations such as pressure drop, throughput and / or mass transfer rate can be optimized.

[0053] The CO2 binding molecule can be an amine or an amine polymer. The amine or amine polymer can contain a mixture of primary amines, secondary amines, tertiary amines or any combination of primary amines, secondary amines and tertiary amines. The amine polymer can be branched, hyperbranched, dendritic or linear. The CO2 binding portion is an amine portion on an amine molecule or polymer. The amine portion can interact with CO2 to form a carbamate, carbonate or bicarbonate substance. Figure 1A Schematic showing how the amine moiety binds CO2 to form carbamate.

[0054] Primary amines are defined as having the chemical structure -NH2R 1 , where R 1 is an alkyl group, such as CH2 or CH3. A secondary amine is defined as having the chemical structure -NHR 1 R 2 , where R 1 and R 2A tertiary amine is defined as having the chemical structure -NR 1 R 2 R 3 , where R 1 , R 2 and R 3 Independently selected from alkyl groups, such as CH2 or CH3.

[0055] The linear amine polymer can be defined as containing only primary amines, secondary amines, or both. The ratio of secondary amines to primary amines can be about 0.5 to 10,000. In one aspect, the molecular weight of the linear amine polymer can be about 100 g / mol to 100,000 g / mol, about 200 to 30,000 g / mol, or about 600 g / mol to 5,000 g / mol.

[0056] Branched amine polymers can be defined as comprising any number of primary amines, secondary amines and tertiary amines that do not overlap with linear amine polymers or dendritic amine polymers. The ratio of primary amines, secondary amines and tertiary amines 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 the skilled person will appreciate, the chemical structure of branched amine polymers can vary greatly and can be very complex. In one aspect, the molecular weight of branched amine polymers can be about 100 g / mol to 100,000 g / mol, about 200 g / mol to 30,000 g / mol or about 600 g / mol to 5,000 g / mol.

[0057] Dendritic amine polymers can be defined as containing only primary and tertiary amines, wherein the group of repeating units is arranged in a manner that is necessarily symmetrical in at least one plane through the center of the molecule (core), wherein each polymer branch is terminated by a primary amine, and wherein each branch point is a tertiary amine. The core or central bond is the same as the branched amine (e.g., ethyleneimine core and ethyleneimine branches, propyleneimine core and propyleneimine branches). The ratio of primary to tertiary amines can be about 1 to 3. In one aspect, the molecular weight of the dendritic amine polymer can be about 100 g / mol to 100,000 g / mol, about 200 g / mol to 30,000 g / mol, or about 280 to 3,000.

[0058] Hyperbranched amine polymers can be defined as having a chemical structure similar to that of dendritic amine polymers, but containing defects in the form of secondary amines (e.g., linear sub-parts present in branched polymers), in this way providing a random chemical structure rather than a symmetrical chemical structure. Hyperbranched amine polymers do not overlap with branched amine polymers or dendritic polymers. In the hyperbranched chemical structure, the ratio of primary amines, secondary amines, and tertiary amines can be about 65:5:30 to 30:10:60. In one aspect, the molecular weight of the hyperbranched amine polymer can be about 100 g / mol to 100,000 g / mol, about 200 g / mol to 30,000 g / mol, or about 600 g / mol to 10,000 g / mol.

[0059] In one aspect, the linear, hyperbranched, and branched amine polymers have secondary amines, whereas the dendritic amines do not, which can be advantageous because secondary amines bind strongly to CO2.

[0060] In one aspect, the amine polymer can be polyethyleneimine, polypropyleneimine, polyallylamine, polyvinylamine, polyglycidylamine, polystyrene-divinylbenzene polymer partially functionalized with an amine such as an alkylbenzylamine, or other amine polymers, each of which can be branched, hyperbranched, dendritic or linear.

[0061] In one embodiment, the size (e.g., length, molecular weight), amount (e.g., number of different amine polymers), and / or type of amine polymer can be selected based on the desired properties of the porous structure (e.g., CO2 absorption, regeneration performance, oxidative stability, loading, etc.).

[0062] In one aspect, the modified amine polymer can comprise a mixture of primary amines, secondary amines, tertiary amines, or any combination of primary amines, secondary amines, and tertiary amines, each of which is as defined above. In one aspect, the amine can be a primary amine and the substituted epoxide can be an alkyl (e.g., straight or branched C1-C20 or straight or branched C1-C10) or a cyclic epoxide. In another aspect, the amine can be a secondary amine and the substituted epoxide can be an alkyl (e.g., straight or branched C1-C20 or straight or branched C1-C10) or a cyclic epoxide. The modified amine polymer can be branched, hyperbranched, dendritic, or linear, each of which is as defined above.

[0063] In one aspect, the modified amine polymer can be a primary or secondary amine prior to reaction with the substituted epoxide to form a secondary or tertiary amine. An exemplary structure is shown below, where R x The substituted group:

[0064]

[0065] In one aspect, R1, R2, R3 and R4 can be hydrogen atom, alkyl, allyl, alkoxy, alkyl halide, aryl, benzyl, phenyl, phenolic group, heteroaryl, nitroimidazole radical etc. and combination thereof (each group can be substituted or unsubstituted independently). On the other hand, R1, R2, R3 and R4 can be hydrogen atom, alkyl, allyl, alkyl halide, aryl, benzyl, phenyl, phenolic group, heteroaryl, nitroimidazole radical etc. and combination thereof (each group can be substituted or unsubstituted independently). In one aspect, each R 'can be independently selected from hydrogen atom, alkyl, alkoxy, alkyl halide, aryl, benzyl, phenyl, phenolic group, amine (for example alkylene imine (C2 to C8) such as ethyleneimine and propyleneimine), heteroaryl, nitroimidazole radical, alkylamino radical etc. and combination thereof (each group can be substituted or unsubstituted independently). On the other hand, each R' can be independently selected from a hydrogen atom, an alkyl group, an alkyl halide, an aryl group, a benzyl group, a phenyl group, a phenolic group, an amine group (e.g., an alkylene imine (C2 to C8) such as ethyleneimine and propyleneimine), a heteroaryl group, a nitroimidazolyl group, an alkylamino group, and the like, and combinations thereof (each group can be independently substituted or unsubstituted).

[0066] In one aspect, the modified amine polymer can be a modified polyethyleneimine, a modified polypropyleneimine, a modified polyallylamine, a modified polyvinylamine, a modified polyglycidylamine, a modified polystyrene-divinylbenzene polymer partially functionalized with an amine such as an alkylbenzylamine, or other modified amine polymer, each of which can be branched, hyperbranched, dendritic or linear, each of which is defined above and herein.

[0067] In one aspect, the fraction of amines modified according to the description herein can be from 0.001 to 1, or from 0.01 to 1, or from 0.1 to 1, or from 0.5 to 1, of the total primary and secondary amines in the amine polymer, or the fraction can be from about 0.01 to 0.5 of the amines in the amine polymer, where a fraction of 1 indicates all are primary and secondary amines.

[0068] In one aspect, the CO2-philic phase includes a modified amine polymer, which is the reaction product of an amine and a substituted epoxide. Substituted epoxide refers to an epoxide with one or more substituents. In addition, it is not an epoxide with a single linear aliphatic group substituent. For example, the substituent may include an alkyl, allyl, alkyl halide, aryl, benzyl, phenyl, phenolic, heteroaryl, nitroimidazole, etc. (each group may be independently substituted or unsubstituted). For example, the substituted epoxide reacted with the amine may include one or more of the following: 1,2-epoxy-2-methylpropane, 2,3-butylene oxide, 3,4-epoxy-1-butene, 3,3-dimethyl-1,2-epoxybutane, 2-methyl-2-vinyl oxirane, 1,2-epoxy-3,3,3-trifluoropropane, 2-phenyl oxirane, 1-(2,3-epoxypropyl)-2-nitroimidazole, pyrrolidine oxide ( For example, trans-pyrene oxide, cis-pyrene oxide, a mixture of trans-pyrene oxide and cis-pyrene oxide), 1,2-epoxy-5-hexene, styrene oxide, (2,3-epoxypropyl)benzene, 2-(4-chlorophenyl)oxirane, 2-(4-bromophenyl)oxirane, 2-(4-fluorophenyl)oxirane, cyclohexene oxide, 4-vinyl-1-cyclohexene-1,2-epoxide or 1,3-butadiene diepoxide.

[0069] In one aspect, the modified amine polymer may have a 1-amino-2-ol structure in addition to the substituents. Although a specific embodiment of the modified amine polymer may be referred to as 1-amino-2-alkyl alcohol, an alternative nomenclature may be 1,2-alkanolamine (1,2-alkanolamine), regardless of the structure described herein. In addition to the substituents, the modified amine polymer may have a 1-aminoalkyl structure, wherein the alkyl structure may be linear and have 1 to 5 carbons in the carbon chain. Prior to the reaction, the amine may be a primary amine or a secondary amine, so as to form a secondary amine or a tertiary amine. Exemplary structures are shown below, wherein R is a substituted group:

[0070]

[0071] In one aspect, R can be an alkyl chain (eg, C2 to C12), an aryl group, a benzyl group, a phenyl group, a phenol group, a heteroaryl group, and the like, and combinations thereof (each group can independently be substituted or unsubstituted).

[0072] While not intending to be bound by theory, the CO2-philic phase modified by reaction with substituted epoxides can adjust the properties of the CO2-philic phase. For example, large substituents such as phenyl or substituted phenyl can be used to sterically block oxygen attack during the oxidation reaction. In addition, the substituent groups can also be used to chemically stabilize the amine polymer to prevent oxidation. Chemical stabilization can be achieved by introducing electron-donating or electron-withdrawing substituents on the amine polymer. The amount, type and mixing amount of the substituted epoxide reacted with the CO2-philic phase can be adjusted and varied to obtain the desired properties of the CO2-philic phase. Adjusting the CO2-philic phase can result in one or a combination of the following improved CO2 adsorbents: increased lifetime due to a reduction in oxidative degradation rate, an increase in the amine efficiency of the adsorbent, an increase in the CO2 swing capacity of the adsorbent during adsorption / desorption, and an increase in the equilibrium capacity of the adsorbent.

[0073] In one aspect, it may be advantageous to increase the stability of the CO2-philic phase relative to process conditions associated with using the adsorbent in a CO2 separation process, particularly during adsorbent regeneration (a process cycle in which the adsorbent temperature is increased to remove bound CO2). It may also be advantageous to increase the stability of the CO2-philic phase under conditions associated with storage of the adsorbent when the adsorbent is not in use in a process or apparatus. It is valuable to have an adsorbent having a CO2-philic phase that has improved stability relative to process conditions that include adsorbent regeneration, storage, or both adsorbent regeneration and storage.

[0074] It is useful to evaluate the oxidative stability of materials in environments containing both oxygen and CO2 because during the regeneration process, at elevated temperatures, desorbed CO2 is present in different concentrations in addition to oxygen and can affect the stability of the material. Additionally, evaluating the oxidative stability of materials in environments containing only oxygen (air without CO2) is an effective method for evaluating the shelf life of materials when stored under ambient conditions.

[0075] As described above, the CO2-philic phase (e.g., CO2-binding molecules) can be homogeneous or heterogeneous. When the CO2-philic phase is heterogeneous, the CO2-binding molecules can exist in a variety of ways. For example, the CO2-binding molecules can be applied or incorporated to form a layer of the CO2-philic phase on a carrier, such as on the pore surface of the carrier. On the other hand, when used independently of or in combination with other aspects such as those described above, the CO2-binding molecules can be used to form part or all of a carrier, wherein the CO2-philic phase works as described herein. Various combinations are contemplated and are part of the present disclosure. Other ways of uniformly and / or non-uniformly applying, using or incorporating the CO2-philic phase are described herein and below.

[0076] As described herein, the adsorbent includes a CO2-philic phase (e.g., a CO2-binding molecule) and a support. The support includes a surface (e.g., a surface that can be exposed to a gas containing CO2 and / or can interact with the CO2-philic phase during normal use). The surface can be a surface of a pore and / or other surface that the CO2-philic phase contacts or interacts with.

[0077] In one aspect, the CO2-philic phase (e.g., CO2-binding molecules) can be disposed on and / or within a carrier to form an adsorbent. The CO2-philic phase can be disposed on the surface of a carrier, and / or within a pore of a carrier, and / or on the outer surface of a carrier, or any combination thereof. In one aspect, the CO2-philic phase can be a coating on a porous material surface, a monolayer on a porous material surface, a self-assembled monolayer on a porous material surface, a bulk phase within a porous material pore, a coating on an outer surface of a porous material, etc.

[0078] In one aspect, the support can be made of one or more types of materials, such as ceramics, metals, metal oxides, plastics, cellulose, carbon, zeolites, metal organic frameworks (MOFs), porous organic frameworks (POFs), covalent organic frameworks (COFs), intrinsically microporous polymers (PIMs), polymers, fibrous cellulose, glass fibers, boron nitride fibers, etc. In another aspect, the support can be made of a material that also includes a CO2-philic phase.

[0079] The metal oxide support may be selected from cordierite, alumina (e.g., γ-alumina, θ-alumina, δ-alumina), cordierite-α-alumina, silica, aluminosilicate, zirconium oxide, germanium oxide, magnesium oxide, titanium oxide, hafnium oxide, silicon nitride, zirconium mullite, spodumene, alumina-silica magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, petalite, and combinations thereof. Where the oxide contains formal charges, the charges may be balanced by appropriate counterions, 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 may contain dopants, such as zirconium, iron, tin, silicon, titanium, magnesium, and combinations thereof. It is well known that metal oxides can contain acid, basic and neutral sites on their surfaces, and that dopants can change the number and strength of acid and basic sites on the surface.

[0080] In one aspect, the polymer support can be a polyolefin, polyester, polyurethane, polycarbonate, polyetheretherketone, polyphenylene oxide, polyethersulfone, melamine, polyamide, polyvinylbenzene, polystyrene-divinylbenzene, polyurethane, polyacrylate, polystyrene, polyacrylonitrile, polyimide, polyfurfural alcohol, phenol furfural alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurate, polyacrylamide, various epoxy resins, agar and agarose, or a combination thereof.

[0081] The support can be porous (e.g., macroporous, mesoporous, microporous, or mixtures thereof (e.g., wherein the macroporous surface can include mesopores and / or micropores within one or more macropores, wherein the mesoporous surface can include micropores, etc.)). In one aspect, the porous structure is mesoporous. The pores can extend through the porous structure or porous layer, or only to a certain depth. The macropores of the porous structure can have a diameter of about 100nm to 10,000nm, a length of about 500nm to 100,000nm, and a volume of 0.2-1cc / g. The mesopores of the porous structure can have a diameter of about 5nm to 100nm, a length of about 10nm to 10,000nm, and a volume of 0.1-2cc / g. The micropores of the porous structure can have a diameter of about 0.5nm to 5nm, a length of about 0.5nm to 1000nm, and a volume of about 0.1-1cc / g.

[0082] The support may 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 60-90%. In some embodiments, the surface area of ​​the support may be 1 m 2 / g or more, 10m 2 / g or more, 100m 2 / g or more, 150m 2 / g or more, 200m 2 / g or more, or 250m 2 / g or more, 500m 2 / g or more, 1000m 2 / g or greater.

[0083] In one embodiment, the CO2-philic phase (e.g., CO2-binding molecules) can be physically impregnated in the internal volume pores of the porous structure without being covalently bound to the inner surface of the pores of the porous structure, can be grafted (e.g., directly or indirectly covalently bound) to the inner surface of the pores of the porous structure, or a combination thereof. In one embodiment, the CO2-philic phase (e.g., CO2-binding molecules) can be covalently bound (e.g., directly bound to the surface or through a linking group) to the surface of a material, which can include a porous layer or the inner surface of the pores of the porous structure. In one aspect, covalent binding can be achieved using techniques known in the art for binding adsorbents. Considering that the CO2-philic phase (e.g., CO2-binding molecules) is physically impregnated in the pores of the porous structure and is not covalently bound to the inner surface of the pores of the porous structure, the CO2-philic phase can be confined within the pores of the carrier, but not bound to the surface. In yet another embodiment, the CO2-philic phase (e.g., CO2-binding molecules) is present in a plurality of pores (internal volume) of a porous structure (a "porous structure" may include a structure having pores on its surface or a structure having a porous layer or coating on the surface of the structure (wherein the structure itself may or may not be porous)), wherein the loading amount of the CO2-philic phase is about 10% to 75% of the weight of the support. With respect to loading, the loading is determined by thermogravimetric analysis (TGA).

[0084] In one embodiment, the carrier may include a surface layer on the surface of the carrier pores, which surface layer may be combined with the CO2-philic phase. In one aspect, the surface layer may include organic modified portions (e.g., alkyls, amines, thiols, phosphines, etc.) on the surface of the material (e.g., the outer surface and / or inner surface of the pores). In one embodiment, the surface layer may include surface alkyls, amines, thiols, phosphines, etc., and the CO2-philic phase may be directly covalently bound and / or indirectly covalently bound (e.g., covalently bound to a linker covalently bound to the material). In one embodiment, the surface layer may include an organic polymer having one or more of the following groups: alkyls, amines, thiols, phosphines, etc. In another embodiment, the structure may be a carbon carrier, wherein the carbon carrier may include one or more of the following groups: alkyls, amines, thiols, phosphines, etc.

[0085] In one embodiment, the CO2-philic phase may occupy about 10% to 100% of the mesoporous volume of the support, or may occupy about 30% to 90% of the mesoporous volume of the support, or may occupy about 40% to 80% of the mesoporous volume of the support, or may occupy about 50% to 70% of the mesoporous volume of the support.

[0086] The methods of making shaped supports or structures described above and herein can be used to make any of the structures listed in this paragraph and the following paragraphs. An adsorbent comprising a CO2-philic phase and a support can be formed or applied to a structure. In one aspect, the CO2-philic phase and the support can form 100% or less than 100% of the structure (e.g., ranging from about 10%, about 20%, about 30%, about 40%, about 50% and about 60%, about 70%, about 80%, about 90%, about 99% of each combination, such as about 10% to 99%, about 10% to 80%, about 10% to 50%, about 50% to 99%, about 50% to 90%, about 50% to 80%), wherein there is a sufficient amount of adsorbent on the surface of the structure to absorb the desired amount of CO2. In one aspect, the structure can be a honeycomb, a laminate, a foam, a fiber, a minimal surface solid, a powder tray, a pellet, a powder, etc., or a combination of two or more of the foregoing.

[0087] In one 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%.

[0088] In one aspect, the pores of the structure can be composed of macropores, mesopores and / or micropores. In one aspect, the CO2-philic phase is mainly (e.g., about 40% to 100% or about 50% to 90%, or about 60% to 80%) located in the mesopores of the structure.

[0089] In one aspect, the structure can consist entirely of the adsorbent, or can include another substrate material, such as a ceramic, a metal, a metal oxide, a plastic, or another material. The structure can be a porous substrate, or can include a porous coating on some or all of the porous substrate, wherein the CO2-philic phase can be present in the pores of one or both of the porous substrate and the porous coating.

[0090] When the structure is composed entirely of adsorbent (e.g., CO2 binding molecules and a support), it can be formed by, for example, extrusion, molding, 3D printing, etc. The structure can be formed using a support material without a CO2-philic phase or using a support to which a CO2-philic phase is already incorporated. When formed without a CO2-philic phase, the CO2-philic phase can be incorporated into the structure by impregnation, grafting, or other functionalization techniques.

[0091] In a specific aspect, the support material can be applied to the substrate as a porous coating (also referred to as a "support coating") on the substrate surface. In one embodiment, the porous coating can be a foam, such as a polymer foam (e.g., polyurethane foam, polypropylene foam, polyester foam, etc.), a metal foam or a ceramic foam. The porous coating can include a metal oxide layer (e.g., foam). For example, the metal oxide layer can be silicon dioxide or aluminum oxide on the substrate surface. The porous coating can be present on the surface of the substrate, in the pores or voids of the substrate, or in a combination thereof. The thickness of the porous coating can be about 50 μm to 1500 μm, and the size of the pores can be as described above and herein.

[0092] In one aspect, the support material, substrate and / or structure can be made of a ceramic substrate, such as cordierite, alumina (e.g., γ-alumina, θ-alumina, δ-alumina), cordierite-α-alumina, silica, aluminosilicate, zirconium oxide, germanium oxide, magnesium oxide, titanium dioxide, hafnium oxide, silicon nitride, zirconium mullite, spodumene, alumina-silica magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, petalite and combinations thereof. The metal or metal oxide structure can be aluminum, titanium, stainless steel, Fe-Cr alloy or Cr-Al-Fe alloy. In the case where the oxide contains formal charges, the charges can be balanced by appropriate counterions, 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, etc.

[0093] In one aspect, the support material, substrate and / or structure can be made of a plastic substrate, which can be made of polyolefins, polyesters, polyurethanes, polycarbonates, polyetheretherketones, polyphenylene oxides, polyethersulfones, melamines, polyamides, polyvinylbenzenes, polystyrene-divinylbenzenes, polyurethanes, polyacrylates, polystyrenes, polyacrylonitrile, polyimides, polyfurfuryl alcohols, phenolfurfuryl alcohols, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehydes, phenol formaldehydes, polyvinyl alcohol dialdehydes, polycyanurates, polyacrylamides, various epoxy resins, agars and agaroses, or combinations thereof.

[0094] In one embodiment, the structure can be a honeycomb structure, such as a honeycomb monolithic structure including a channel. The honeycomb structure can have a regular corrugated structure. The length and width of the honeycomb monolithic structure can be in the order of centimeters to meters, and the thickness can be in the order of millimeters to centimeters or more. On the one hand, the honeycomb monolithic structure does not have a fiber size. In other words, the honeycomb structure can be a flow-through substrate including an open channel defined by a channel wall. The channel can have about 50 to about 900 cells per square inch. The cross-section of the channel can be polygonal (e.g., square, triangle, hexagon, octagon), sinusoidal, circular, etc. Along the length of the channel, the channel length can have a straight, zigzag, skewed or herringbone configuration. The length of the channel can be 1 mm to tens or hundreds of centimeters or longer. The channel can have a perforated or louvered wall. In one aspect, the adsorbent can be arranged in the holes of the honeycomb structure and / or in the holes of the porous layer on the surface of the honeycomb structure. The geometric void ratio (also referred to as the open area) of the honeycomb structure can be 0.3 to 0.95 or about 0.5 to 0.9.

[0095] In one embodiment, the honeycomb structure may include an inlet end, an outlet end, and an internal channel extending from the inlet end to the outlet end. In some embodiments, the honeycomb includes a plurality of cells extending from the inlet end to the outlet end, the cells being defined by intersecting cell or channel walls.

[0096] In one aspect, the honeycomb structure and / or substrate can be ceramic (e.g., manufactured by Corning under the trade name Type) which can be used with adsorbents according to the principles of the present disclosure. The adsorbent can be coated or otherwise fixed inside the pores of the ceramic honeycomb structure and / or within a porous layer on the surface of the ceramic honeycomb structure. In one aspect, the porous coating can include a metal oxide layer on the surface of the substrate, such as silicon dioxide or aluminum oxide. In one embodiment, the metal oxide layer can be mesoporous and macroporous. The depth of the honeycomb as a whole can be 3 inches to 10 feet, or about 3 to 24 inches.

[0097] In one aspect, the structure can be a laminate. A laminate is a structure comprising a one-dimensional wall structure whereby plates are stacked on top of each other with spaces between each plate so that gas can flow between the plates.

[0098] In one aspect, the structure can be a foam. A foam is a structure having an irregular channel structure surrounded by an irregular solid structure. The solid structures are interconnected so that the foam material is self-supporting.

[0099] In one aspect, the structure can be a plurality of fibers. A fiber is a structure having a high aspect ratio and can be arranged in a regular array relative to one another when supported at least at one end of the fiber in a gas contacting application. The fiber can be solid or hollow.

[0100] In one aspect, the structure can be a minimum surface solid. Minimum surface solids are structures often used in packings for distillation and absorption systems to increase the contact area with materials and fluids. Minimum surface area solids refer to geometric shapes with an average surface area of ​​zero, including shapes such as solids of revolution. For example, a solid of revolution can be a sinusoidal.

[0101] In one aspect, the structure can be a powder tray. A powder tray is a structure in which a tray holds loose powder or pellets of the adsorbent of the present invention to form a structured contactor, without the material itself forming a self-supporting structure. The powder tray can be arranged in stacked layers to form a plate, thereby forming a structure similar to a laminate. These layers can be formed using flexible plates, rigid plates or other flat surfaces mounted on a rigid frame structure. Powders are loose, free-flowing solids with a small characteristic particle diameter to provide a powdery consistency. Pellets are beads, balls or other dense structures that are used to provide structure and surface area for the adsorbent.

[0102] In one aspect, the structure can be a volume of adsorbent particles. The adsorbent particle volumes can be contained by one or more walls so that gas can pass through them while keeping the adsorbent contained. The adsorbent particle volumes can be arranged relative to other adsorbent particle volumes, such as to approximate a honeycomb, fiber, or other structured contactor with solids.

[0103] In one aspect, adsorbents in the form of contactors (e.g., structures) are effective embodiments of an efficient method for capturing CO2 from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas, or other gas containing CO2) because the structured contactor or contactors can be designed to provide high surface area and low pressure drop for air treatment. The contactor can be in the form of honeycombs, laminates, foams, fibers, minimum surface solids, powder trays, pellets, powders, etc., or a combination of two or more of the foregoing forms.

[0104] Now that embodiments of the adsorbent and structure have been described, additional details are provided regarding the systems and methods of the present disclosure. The present disclosure provides a method for capturing CO2 from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas, or other gas containing CO2). The method includes introducing ambient air into an adsorbent (e.g., a structure); heating the adsorbent (e.g., about 10°C to 200°C above a conventional adsorbent temperature to absorb CO2) to at least a first temperature to controllably release CO2; and collecting CO2 in a CO2 collection device. The temperature increase in the adsorbent can be performed by contacting the adsorbent with a gas at an elevated temperature, contacting the adsorbent with a fluid at an elevated temperature, contacting the adsorbent with a heat exchanger through which a hot fluid or gas flows, by heating the walls of a container, vessel, or other enclosed device containing the adsorbent, or by contacting the adsorbent with steam (e.g., the temperature of the steam can be between 60°C and 200°C and can be saturated or superheated). In one aspect, the method can be implemented using the system described below.

[0105] The present disclosure provides a system and device for capturing CO2 from ambient air or other gas mixtures (e.g., flue gas, exhaust gas, natural gas or other gases containing CO2), wherein removing CO2 is important. Typically, the system includes a first device, which is configured to introduce ambient air or other gas mixtures into an adsorbent or contactor, wherein the adsorbent or contactor includes those described herein. The adsorbent is exposed to ambient air or other gas mixtures for a period of time (e.g., several hours). In a specific aspect, the adsorbent is a honeycomb integral body with an open surface area of ​​0.3-0.95. The first device is configured to deliver ambient air to the honeycomb integral body at a speed of 0.25-10 m / s. After the desired time, the second device is configured to heat the adsorbent containing CO2 to at least a first temperature (e.g., about 40°C to 200°C, about 50°C to 200°C or about 60°C to 200°C) to release CO2. The second device of the system can desorb CO2 by an adsorbent. The second device may include components that support temperature swings, pressure swings, steam swings, concentration swings, combinations thereof, or other dynamic processes to desorb CO2. In one embodiment, the steam swing process may include exposing the adsorbent to steam, wherein 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. The third device is configured to collect the released CO2. The system can be operated so that the adsorbent absorbs and desorbs CO2 in an efficient and cost-effective manner.

[0106] Aspects of the present disclosure may be described by the following paragraphs.

[0107] The present disclosure provides an adsorbent, which includes: a CO2-philic phase and a carrier, wherein the CO2-philic phase includes the reaction product of a substituted epoxide and an amine. The amine is an amine polymer. The amine polymer can be branched, hyperbranched, dendritic or linear. The amine polymer is one of polyethyleneimine, polypropyleneimine, polyallylamine, polyvinylamine, polyglycidylamine or polystyrene-divinylbenzene polymer functionalized with amine or other amine polymers. The CO2-philic phase is homogeneous. The CO2-philic phase is heterogeneous. The fraction of amines modified by reaction with substituted epoxides is about 0.001 to 1 of the total primary and secondary amines in the amine polymer, wherein a fraction of 1 indicates that all are primary and secondary amines. The fraction of amines modified by reaction with substituted epoxides is about 0.01 to 0.5 of the total primary and secondary amines in the amine polymer, wherein a fraction of 1 indicates that all are primary and secondary amines. The amine polymer is physically impregnated into the pores of the carrier. The amine polymer is physically impregnated onto the surface of the carrier. The amine polymer is covalently bound to the surface of the support. The substituted epoxide is 1,2-epoxy-2-methylpropane, 2,3-epoxybutane, 3,4-epoxy-1-butene, 3,3-dimethyl-1,2-epoxybutane, 2-methyl-2-vinyloxirane, 1,2-epoxy-3,3,3-trifluoropropane, 2-phenyloxirane, 1-(2,3-epoxypropyl)-2-nitroimidazole, trans-pyrene oxide, cis-pyrene oxide, a mixture of trans-pyrene oxide and cis-pyrene oxide, 1,2-epoxy-5-hexene, styrene oxide, (2,3-epoxypropyl)benzene, 2-(4-chlorophenyl)oxirane, 2-(4-bromophenyl)oxirane, 2-(4-fluorophenyl)oxirane, cyclohexene oxide, 4-vinyl-1-cyclohexene-1,2-epoxide or 1,3-butadiene diepoxide. The CO2-philic phase includes at least one structure selected from the following structures, wherein R x The substituted group:

[0108]

[0109] Wherein R1, R2, R3 and R4 are each independently selected from hydrogen atoms, alkyl groups, allyl groups, alkoxy groups, alkyl halides, aryls, benzyl groups, phenyl groups, phenol groups, heteroaryls, nitroimidazole groups, etc. and combinations thereof (each group can be independently substituted or unsubstituted), and wherein each R' is independently selected from hydrogen atoms, alkyl groups, alkoxy groups, alkyl halides, aryls, benzyl groups, phenyl groups, phenol groups, amine groups (e.g., alkylene imines (C2 to C8) such as ethyleneimine and propyleneimine), heteroaryls, nitroimidazole groups, alkylamino groups and combinations thereof (each group can be independently substituted or unsubstituted). The carrier is a ceramic, a metal, a metal oxide, a plastic, cellulose, carbon, a zeolite, a metal organic framework (MOF), a porous organic framework (POF), a covalent organic framework (COF), an intrinsic microporous polymer (PIM), a polymer, a fibrous cellulose, a glass fiber or a boron nitride fiber.

[0110] The present disclosure provides a contactor comprising a structure and an adsorbent as described above and herein. The structure is selected from a honeycomb, a laminate, a foam, a fiber, a minimum surface solid, a powder tray, a pellet, or a combination thereof.

[0111] The present disclosure provides a system for capturing CO2 from a gas, optionally the gas is ambient air, the system comprising: a first device configured to introduce a gas into an adsorbent or contactor as described above and herein to bind CO2 to the adsorbent; a second device configured to heat the adsorbent containing bound CO2 to at least a first temperature to release CO2; and a third device configured to collect the released CO2. After heating, the adsorbent is regenerated so that the adsorbent can absorb CO2 from the gas. The adsorbent is in the form of a honeycomb, a laminate, a foam, a fiber, a minimum surface solid, a powder tray, a pellet, and a combination thereof. The open face area of ​​the honeycomb is 0.3-0.95. The gas approaches the honeycomb at a speed of 0.25-10 m / s. The system is configured to operate to remove CO2 from ambient air, wherein the ambient air has a low concentration of CO2.

[0112] The present disclosure provides a method for capturing CO2 from a gas, optionally the gas is ambient air, the method comprising: introducing ambient air to an adsorbent as described above and herein to bind CO2 to the adsorbent; heating the adsorbent to at least a first temperature to controllably release CO2 and collecting CO2 in a CO2 collection device. Heating the adsorbent regenerates the adsorbent so that the adsorbent is able to absorb CO2 from ambient air. The adsorbent is heated by contacting the adsorbent with steam. The method is configured to operate to remove CO2 from ambient air, wherein the ambient air has a low concentration of CO2. The adsorbent is in the form of a honeycomb, a laminate, a foam, a fiber, a minimal surface solid, a powder tray, a pellet, and combinations thereof.

[0113] The present disclosure provides a system for implementing the methods described above and herein.

[0114] Example

[0115] Removing CO2 from ambient air through engineered chemical processes, also known as direct air capture (DAC), is emerging as an important environmental technology for mitigating climate change. DAC is a technology that can provide negative emissions, removing CO2 from the atmosphere. However, current DAC technology is expensive, which limits its application. Therefore, there is a need for improved DAC technology. Many DAC technologies rely on solid adsorbent materials as a medium to separate CO2 from the air. These adsorbents are typically applied in a temperature swing process, during which, at low temperatures, CO2 in the air binds to sites therein, and then at high temperatures, the CO2 is released into a concentrated product that can be isolated or sold as a product. Many DAC adsorbents use amines to bind CO2 in this way. Certain amine types can effectively bind CO2 at low concentrations, such as those found in air (400ppm).

[0116] While some amine types are effective at binding CO2 from ambient air, they are slowly oxidized in air by ambient oxygen. This effect is exacerbated in process cycles that increase the adsorbent temperature to remove bound CO2, thereby accelerating oxidative degradation and shortening the life of the CO2 adsorbent. Therefore, there is a need for adsorbents with improved oxidative stability that can effectively remove CO2 from ambient air.

[0117] Some adsorbents used in the DAC process are composite materials, including a CO2-philic phase (e.g., CO2-binding molecules and phenol-containing molecules) distributed in or inside a solid material, which provides surface area for it. The CO2-philic phase can be grafted to a solid surface, physically impregnated into the pores of a solid material, or physically loaded on the surface of a solid material. The CO2-philic phase of these adsorbents can be an amine or other molecule capable of binding CO2. In some cases, the amine can be a polymeric amine, such as polyethyleneimine, polypropyleneimine, polyallylamine, polyethyleneamine, polybutylamine, etc. These polymeric amines can be linear, branched, hyperbranched, dendritic, or in the form of some other macromolecules. In other cases, the amine can be a small molecule, such as TEPA, TPTA, etc. In other cases, the amine can be an aminosilane. The solid support material can be a metal oxide, carbon, metal, or other structure, which can provide sufficient surface area for the CO2-philic phase to be deposited, to allow useful CO2 adsorption and desorption capacity and kinetics. In this way, the solid support material is functionalized by the CO2-philic phase to produce a composite adsorbent.

[0118] The adsorbent can be formed or incorporated into a macrostructure or contactor to provide advantages in applications such as DAC. Such a structure can be a honeycomb monolith, laminate, pellet, or other structure that provides a high geometric surface area for air or a gas containing CO2 to effectively contact the adsorbent so that CO2 can bind to the adsorbent.

[0119] Adsorbents can be used in processes to capture CO2 from air or various other gas streams such as flue gas, natural gas, etc. These processes are referred to as "CO2 capture processes". CO2 capture processes can use temperature swing, concentration swing, pressure swing, stripping or other temperature swing technologies to remove CO2 that has bound to the surface of the adsorbent.

[0120] There is relatively little development on the use of polyethyleneimine to improve CO2 adsorbents, especially for DAC applications.

[0121] Having now described embodiments of the present disclosure, in general, the following examples describe some additional embodiments of the present disclosure. Although embodiments of the present disclosure are described in conjunction with these examples and corresponding text and drawings, it is not intended that the embodiments of the present disclosure be limited to these descriptions. On the contrary, it is intended to cover all replacements, modifications, and equivalents contained within the spirit and scope of the embodiments of the present disclosure.

[0122] Example: Schematic diagram showing an adsorbent with a support material and a CO2-philic phase

[0123] Figure 1B The main components of the adsorbent system are shown. The adsorbent system consists of a support material and a CO2-philic phase. In the schematic diagram shown, a single CO2-philic phase is shown bonded to a single support. The CO2-philic phase shown is polyethyleneimine (PEI). A known adsorption product of CO2 and PEI is ammonium carbamate. Mesoporous alumina is shown as a support.

[0124] Example: Schematic diagram of a honeycomb structure including an adsorbent carrier coating

[0125] Figure 2 An embodiment of a honeycomb monolith contactor is shown. The figure shows the main geometric features of the honeycomb monolith, which has straight flow channels surrounded by walls. The figure schematically shows a support coating applied to the walls, wherein the support coating consists of an adsorbent. The adsorbent consists of a support material and a CO2-philic phase (such as PEI).

[0126] Example: Substituted Epoxides Evaluated as Polyethyleneimine (PEI) Modifiers

[0127] Various substituted epoxides were evaluated for their ability to reduce the oxidation rate when reacted with PEI and incorporated into the support. Substituted epoxides and their reference names are given in Figure 3 .

[0128] Example: Preparation of Improved CO2 Adsorbents Containing Polyethyleneimine (PEI) Reacted with Substituted Epoxides

[0129] Branched polyethyleneimine (PEI) MW 800 is available from SigmaAldrich. The table below lists the substituted epoxides used. PEI was dissolved in a methanol solution, after which a single epoxide was added in a ratio corresponding to 0.5 moles of epoxide per mole of primary amine present in PEI. The mixture was stirred at room temperature for about 6 hours to 24 hours or about 12 hours to 24 hours to react the epoxide with the PEI. Separately, the mesoporous alumina was dispersed in methanol and mixed until uniform. The epoxy-functionalized PEI solution was then pipetted into the alumina / methanol dispersion. After stirring for more than 3 hours, the solvent was removed by rotary evaporation and then dried in a vacuum oven at 100°C for 10 hours. The mass ratio of alumina and epoxy-functionalized PEI was controlled to achieve 40-80% filling of the mesopores of the mesoporous alumina by epoxy-functionalized PEI. The resulting composite adsorbent was a powdery consistency.

[0130]

[0131]

[0132] Example: Characterization of Improved CO2-Affinic Phases and CO2 Adsorbents

[0133] Chemical characterization was performed to confirm the nature of the improved CO2-philic phases. Further chemical characterization was performed to confirm that these CO2-philic phases were successfully incorporated into the pores of the mesoporous support to produce a CO2 sorbent.

[0134] PEI and the materials obtained by reacting PEI with various substituted epoxides were subjected to 1 H NMR experiments were performed to characterize the properties of the obtained materials.

[0135] TGA burnout experiments were performed on adsorbents composed of modified CO2-philic phases to characterize the total amount of organic matter present in the adsorbent. The sample was heated to 900 °C under dilution air and its mass loss was tracked. After removing the effects of CO2 and H2O lost at lower temperatures, the total organic content was taken as the mass loss in this temperature interval.

[0136] Example: TGA burnout experiment

[0137] Figure 4 and Figure 5The mass loss and heat flow (DSC) curves of the materials during exposure to dilute air are shown when the temperature is increased from room temperature to 900°C. These figures show that both the natural PEI adsorbent and the modified PEI adsorbent lost most of their mass during the experiment because the organic part of the material was burned off under oxidative conditions. The DSC curves reveal different oxidation curves of the materials during the exposure process, and also confirm that the PEI has been modified by the reaction.

[0138] Example: Testing during CO2 adsorption

[0139] The adsorbent produced with the modified CO2-philic phase was tested for CO2 adsorption in a TGA at 400 ppm CO2 and 30°C to simulate the gas contact step of the direct air capture process. The adsorbent was first treated in N2 at 100°C to desorb any bound H2O and CO2, and then equilibrated at 30°C under N2. The gas concentration was then isothermally switched to contain 400 ppm CO2, equilibrated by N2, and the mass change recorded. Under these moisture-free conditions, the mass increase of the material corresponds to the adsorption of CO2 and can therefore be used to measure the total amount and rate of CO2 adsorption onto the material.

[0140] The CO2 adsorption of various improved adsorbents was characterized using this method and compared to a baseline PEI based adsorbent. Adsorbents produced using PEI reacted with various substituted epoxides at a loading of 0.5 moles of substituted epoxide / mole of primary nitrogen in PEI were evaluated relative to adsorbents containing PEI alone.

[0141] Adsorbents were evaluated based on two bases, i) CO2 capacity, mmol of CO2 adsorbed per mole of adsorbent, and ii) amine efficiency, mmol of CO2 adsorbed per mole of N in PEI present in the sample. The former performance unit can be used to show overall adsorbent performance, the second performance unit can be used to evaluate the performance of the amine polymer itself and take into account variations in the overall composition of the adsorbent.

[0142] Example: CO2 adsorption capacity of PEI supported on mesoporous alumina and modified CO2-philic phase at 400 ppm CO2.

[0143] Figure 6 The transient TGA absorption curves of the adsorbent prepared by reacting PEI with substituted epoxides under DAC conditions are shown in Fig. Figure 3The amines are labeled by their reference, each with 0.5 mol of substituted epoxide / mol of primary nitrogen in PEI, and compared to unmodified PEI. Each adsorbent was able to adsorb CO2 under ultra-dilute conditions of 400 ppm, with varying degrees of amine efficiency. Compared to PEI, reactions with epoxide 11, epoxide 9, epoxide 6, and epoxide 7 did not appear to affect the material's ability to adsorb CO2. Reactions with epoxide 5, epoxide 8, and epoxide 12 reduced the ability to absorb CO2 to some extent, and reaction with epoxide 10 appeared to result in a loss of almost all of the ability to absorb CO2. This was an unexpected result because epoxidation of amines converts primary amines to secondary amines, and secondary amines to tertiary amines. Secondary amines are thought to have a less favorable interaction potential with CO2 than primary amines due to the steric hindrance of the additional groups that bind to them. It is well known that tertiary amines do not interact with CO2 under dry conditions, such as those tested here. Therefore, this result shows that, unexpectedly, epoxidation of PEI does not generally result in a significant loss in the performance of PEI as a CO2-philic phase. Furthermore, the reaction with the substituted epoxides increased or maintained the initial adsorption rate of CO2 compared to PEI, except for epoxide 10. The initial adsorption rates followed the following trend: PEI-0.5 epoxide 9 ≈ PEI-0.5 epoxide 11 ≈ PEI-0.5 epoxide 6 ≈ PEI-0.5 epoxide 7 > PEI-0.5 epoxide 8 ≈ PEI-0.5 epoxide 5 ≈ PEI ≈ PEI-0.5 epoxide 12 > PEI-0.5 epoxide 10. This suggests that epoxidation of PEI with substituted epoxides can increase the CO2 adsorption rate, allowing the adsorbent to reach equilibrium faster when adsorbing CO2 from air or other dilute streams. This unexpected result can be explained by the creation of void space in the CO2-philic phase by the epoxide side chains, which allows unbound CO2 to diffuse into the CO2-philic phase more easily compared to unmodified PEI.

[0144] Example: Oxidation Stability Test

[0145] The oxidative stability of a material can be studied in a variety of ways. In this study, the oxidative stability of the adsorbent was evaluated by using DSC to track the heat flow generated by the material during exposure to isothermal oxidative conditions. Here, the adsorbent was first treated at 100°C in an inert gas to desorb any bound H2O and CO2, and then equilibrated at 125°C, 137.5°C, or 150°C in an inert gas for 60 minutes. The gas was then isothermally switched to a 17% O2 mixture (air or air without CO2) and maintained until the reaction was complete. 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 to room temperature under N2. In these experiments, for each oxidative condition, the DSC measured the increment in heat flux, which increased, stabilized, and then dropped to zero. Oxidation was considered complete when the integrated heat flow change over 10 minutes was less than ±0.01% of the total integrated heat. To determine the extent of oxidation as a function of time, the DSC data were converted from the base unit of mW / mg adsorbent to W / gPEI using the PEI loading measured by TGA burnout. The DSC data were corrected for drift by applying an offset determined by the heat flow value when the DSC curve is close to a horizontal line. The total heat evolved was calculated by integrating the heat flow over time. The DSC extent of oxidation was calculated by dividing the integrated heat flow curve by the total heat evolved. This method has been previously calibrated using the loss of amine efficiency as a method to track the chemical reaction rate of in situ oxidative degradation, such as Figures 7A-7D More details about 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. The papers are incorporated herein by reference.

[0146] Figure 8 The oxidation curves of CO2 adsorbents produced by the reaction of PEI and PEI with substituted epoxides in the presence of CO2-free air are shown. Figure 3 The ratio of 0.5 moles of substituted epoxide per mole of primary nitrogen in PEI is labeled and supported in mesoporous alumina. The figure shows two general categories of behavior; some substituted epoxides accelerate the oxidation of PEI, while most substituted epoxides slow the oxidation rate of PEI, although to varying degrees. In particular, epoxide 5, epoxide 6, epoxide 7, epoxide 8, epoxide 9, epoxide 11, and epoxide 12 slow the oxidation rate when reacting with PEI, while epoxide 10 accelerates the oxidation rate when reacting with PEI. Figure 8The differences in the extent of oxidation observed between the differently substituted epoxides suggest that not all substituted epoxides increase or decrease the oxidation rate and, in fact, some substituted epoxides accelerate the oxidation rate compared to PEI, as is the case with epoxide 10 (1-(2,3-epoxypropyl)-2-nitroimidazole).

[0147] An example structure of a modified amine on a modified amine polymer is Fig. 9 shown.

[0148] An example chemical structure of a 1-amino-2-ol group that reacts with a primary amine to form a secondary amine is Fig.10 shown.

[0149] It should be noted that ratios, concentrations, quantities and other numerical data may be expressed in the form of ranges herein. It should be understood that such range forms are used for convenience and brevity, and therefore, should be interpreted in a flexible manner as not only including the numerical values ​​clearly listed as range limits, but also including all single numerical values ​​or sub-ranges contained within the range, as if each numerical value and sub-range is clearly listed. For illustration, the concentration range of "about 0.1% to about 5%" should be interpreted as not only including the concentration of about 0.1% by weight to about 5% by weight clearly listed, but also including single concentrations (e.g., 1%, 2%, 3% and 4%) and sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3% and 4.4%) within the indicated range. In one aspect, the term "about" may include traditional rounding according to the significant figures of the numerical value. In addition, the phrase "about 'x' to 'y'" includes "about 'x' to about 'y'".

[0150] Many variations and modifications may be made to the above-described aspects. All such modifications and variations are intended to be included within the scope of this disclosure and protected by the accompanying claims.

Claims

1. An adsorbent comprising: A CO2-philic phase and a support, wherein the CO2-philic phase comprises the reaction product of a substituted epoxide and an amine.

2. The adsorbent according to claim 1, wherein the amine is an amine polymer.

3. The adsorbent according to claim 2, wherein the amine polymer can be branched, hyperbranched, dendritic or linear.

4. The adsorbent according to claim 3, wherein the amine polymer is one of polyethyleneimine, polypropyleneimine, polyallylamine, polyvinylamine, polyglycidylamine, or a polystyrene-divinylbenzene polymer functionalized with an amine.

5. The adsorbent according to claim 1, wherein the CO2-philic phase is homogeneous.

6. The adsorbent according to claim 1, wherein the CO2-philic phase is heterogeneous.

7. The adsorbent of claim 1, wherein the fraction of amines modified by reaction with substituted epoxides is about 0.001 to 1 of the total primary and secondary amines in the amine polymer, wherein a fraction of 1 indicates all are primary and secondary amines.

8. The adsorbent of claim 1 wherein the fraction of amines modified by reaction with substituted epoxides is about 0.01 to 0.5 of the total primary and secondary amines in the amine polymer, wherein a fraction of 1 indicates all are primary and secondary amines.

9. The adsorbent of claim 2, wherein the amine polymer is physically impregnated into the pores of the support.

10. The adsorbent according to claim 2, wherein the amine polymer is physically impregnated onto the surface of the support.

11. The adsorbent according to claim 2, wherein the amine polymer is covalently bound to the surface of the support.

12. The adsorbent according to claim 1, wherein the substituted epoxide is 1,2-epoxy-2-methylpropane, 2,3-epoxybutylene, 3,4-epoxy-1-butene, 3,3-dimethyl-1,2-epoxybutylene, 2-methyl-2-vinyloxirane, 1,2-epoxy-3,3,3-trifluoropropane, 2-phenyloxirane, 1-(2,3-epoxypropyl)-2-nitroimidazole, trans-pyrene oxide, cis-pyrene oxide, a mixture of trans-pyrene oxide and cis-pyrene oxide, 1,2-epoxy-5-hexene, styrene oxide, (2,3-epoxypropyl)benzene, 2-(4-chlorophenyl)oxirane, 2-(4-bromophenyl)oxirane, 2-(4-fluorophenyl)oxirane, cyclohexene oxide, 4-vinyl-1-cyclohexene-1,2-epoxide or 1,3-butadiene diepoxide.

13. The adsorbent according to claim 1, wherein the CO2-philic phase comprises a structure selected from at least one of the following structures, wherein R x The substituted group: Wherein R1, R2, R3 and R4 are each independently selected from hydrogen atom, alkyl, allyl, alkoxy, alkyl halide, aryl, benzyl, phenyl, phenol, heteroaryl, nitroimidazole, etc. and combinations thereof, wherein each R' is independently selected from hydrogen atom, alkyl, alkoxy, alkyl halide, aryl, benzyl, phenyl, phenol, amine, heteroaryl, nitroimidazole, alkylamino and combinations thereof.

14. The adsorbent according to claim 1, wherein the support is ceramic, metal, metal oxide, plastic, cellulose, carbon, zeolite, metal organic framework (MOF), porous organic framework (POF), covalent organic framework (COF), intrinsic microporosity polymer (PIM), polymer, fibrous cellulose, glass fiber or boron nitride fiber.

15. A contactor comprising a structure and an adsorbent according to any one of claims 1 to 14.

16. The contactor of claim 15, wherein the structure is selected from a honeycomb, a laminate, a foam, a fiber, a minimal surface solid, a powder tray, a pellet, or a combination thereof.

17. A system for capturing CO2 from a gas, optionally the gas being ambient air, the system comprising: a first device configured to introduce a gas into the adsorbent or contactor of any one of claims 1 to 16 to bind CO2 to the adsorbent; a second device configured to heat a sorbent containing bound CO2 to at least a first temperature to release the CO2; and A third device is configured to collect the released CO2.

18. The system of claim 17, wherein after heating, the sorbent is regenerated such that the sorbent is able to absorb CO2 from the gas.

19. The system of claim 17, wherein the adsorbent is in the form of a honeycomb, a laminate, a foam, a fiber, a minimal surface solid, a powder tray, a pellet, and combinations thereof.

20. The system of claim 19, wherein the open face area of ​​the honeycomb is 0.3-0.

95.

21. The system of claim 20, wherein the gas approaches the honeycomb at a velocity of 0.25-10 m / s.

22. The system of claim 20, wherein the system is configured to operate to remove CO2 from ambient air, wherein the ambient air has a low concentration of CO2.

23. A method of capturing CO2 from a gas, optionally the gas being ambient air, the method comprising: introducing the ambient air to the sorbent of any one of claims 1 to 16 to bind CO2 to the sorbent; heating the adsorbent to at least a first temperature to controllably release the CO2, and The CO2 is collected in a CO2 collection device.

24. The method of claim 23, wherein heating the adsorbent regenerates the adsorbent so that the adsorbent is able to absorb CO2 from ambient air.

25. The method of claim 23, wherein the adsorbent is heated by contacting the adsorbent with steam.

26. The method of claim 23, wherein the method is configured to operate to remove CO2 from ambient air, wherein the ambient air has a low concentration of CO2.

27. The method of claim 23, wherein the adsorbent is in the form of a honeycomb, a laminate, a foam, a fiber, a minimal surface solid, a powder tray, a pellet, and combinations thereof.

28. A system for implementing the method of any one of claims 24 to 27.

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