Polyguanidine-containing membranes and methods of using same

Abstract

Described herein are membranes, methods for making membranes, and methods for using membranes. The membranes can include a support layer and a selective polymer layer disposed (e.g., coated) on the support layer. The selective polymer layer can include a polymer matrix including a polyguanidine polymer. Optionally, the polymer matrix can further include a hydrophilic polymer, an amine-containing polymer, or a combination thereof. In some embodiments, the selective polymer layer can further include a mobile carrier (e.g., a guanidine-based mobile carrier, an amine-based mobile carrier, or a combination thereof) dispersed in the polymer matrix. Optionally, the selective polymer layer can further subsequently include a CO2-philic ether, graphene oxide, carbon nanotubes, or a combination thereof dispersed in the polymer matrix. The membranes can be used to separate carbon dioxide from other gases, such as hydrogen and / or nitrogen. Methods for separating gas streams using the membranes described herein are also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 405,825, filed September 12, 2022, which is incorporated herein by reference in its entirety.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under Grant / Contract No. DE-FE0031731 awarded by the Department of Energy. The government has certain rights in this invention. [Background technology]

[0003] Concerns about global warming have been growing as atmospheric CO2 concentrations have exceeded 400 ppm over the past decade. Fossil fuel combustion is one of the main sources of massive CO2 emissions. Various strategies have been proposed to address CO2 emissions. For example, membrane technology has been proposed as a promising approach for capturing CO2 from large-scale stationary sources. Once captured, CO2 can be compressed and geologically sequestered. However, the successful implementation of these solutions requires improved membranes for CO2 separation. Summary of the Invention

[0004] Disclosed is a membrane that includes a support layer and a selective polymer layer disposed (e.g., coated) on the support layer. The selective polymer layer can include a polymer matrix that includes a polyguanidine polymer.

[0005] In some examples, the polyguanidine polymer is polyethylene guanidine, polytrimethylene guanidine, polytetramethylene guanidine, polypentamethylene guanidine, polyhexamethylene guanidine, polyheptamethylene guanidine, polyoctamethylene guanidine, polyethylene N-methylguanidine, polytrimethylene N-methylguanidine, polytetramethylene N-methylguanidine, polypentamethylene N-methylguanidine, polyhexamethylene N-methylguanidine, polyheptamethylene N-methylguanidine, polyoctamethylene N-methylguanidine, polyethylene N,N'-dimethylguanidine, poly The polyguanidine polymer may be selected from trimethylene N,N'-dimethylguanidine, polytetramethylene N,N'-dimethylguanidine, polypentamethylene N,N'-dimethylguanidine, polyhexamethylene N,N'-dimethylguanidine, polyheptamethylene N,N'-dimethylguanidine, polyoctamethylene N,N'-dimethylguanidine, poly(N-vinylguanidine), poly(N-allylguanidine), poly(N-butylguanidine), poly(N-pentylguanidine), poly(N-hexylguanidine), poly(N-heptylguanidine), poly(N-octylguanidine), copolymers thereof, and blends thereof. In certain embodiments, the polyguanidine polymer may comprise polyethylene guanidine (PEG).

[0006] In some embodiments, the polyguanidine polymer may be present in the selective polymer layer in an amount of 10% to 70% by weight, based on the total dry weight of the selective polymer layer.

[0007] Optionally, the polymer matrix may further comprise a hydrophilic polymer, an amine-containing polymer, or a combination thereof.

[0008] In some examples, the amine-containing polymer is selected from the group consisting of polyvinylamine, polyallylamine, polyethyleneimine, poly-N-isopropylallylamine, poly-N-tert-butylallylamine, poly-N-1,2-dimethylpropylallylamine, poly-N-methylallylamine, poly-N,N-dimethylallylamine, poly-2-vinylpiperidine, poly-4-vinylpiperidine, polyaminostyrene, chitosan, copolymers, and blends thereof. In certain embodiments, the amine-containing polymer comprises polyvinylamine.

[0009] In some examples, the hydrophilic polymer may comprise a polymer selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyethylene oxide, polyvinylpyrrolidone, polyacrylamine, polyamine, such as polyallylamine, polyvinylamine, or polyethyleneimine, polysiloxane, copolymers thereof, and blends thereof.

[0010] Optionally, the selective polymer layer further comprises a mobile carrier dispersed in the polymer matrix. The mobile carrier may comprise a guanidine-based mobile carrier, an amine-containing mobile carrier, or a combination thereof. In some embodiments, the mobile carrier may have a molecular weight of less than 1,000 Da.

[0011] In some examples, the mobile carrier is 1,1,3,3-tetramethylguanidine, piperazine-1-carboximidamide, N-methylpiperazine-1-carboximidamide, N-ethylpiperazine-1-carboximidamide, N-propylpiperazine-1-carboximidamide, N-butylpiperazine-1-carboximidamide, N-pentylpiperazine-1-carboximidamide, N-hexylpiperazine-1-carboximidamide, N-heptylpiperazine-1-carboximidamide, N-octyl ...hexylpiperazine-1-carboximidamide, N-hexylpiperazine-1-carboximidamide, N-hexylpiperazine- Carboximidamide, 2-(1-piperazinyl)ethylamine sarcosinate, 2-(1-piperazinyl)ethylamine glycinate, 2-(1-piperazinyl)ethylamine aminoisobutyrate, piperazine sarcosinate, piperazine glycinate, piperazine aminoisobutyrate, lithium sarcosinate, lithium glycinate, lithium aminoisobutyrate, potassium sarcosinate, potassium glycinate, potassium aminoisobutyrate, amidines having the structure R1-(C=NH)-NR2R3 (wherein each of the R1, R2, and R3 groups is H or R=C n H 2n+1 where n ranges from 1 to 10), guanidines having the structure R1-N(R2)-(C=NH)-NR3R4 (where each of the R1, R2, R3, and R4 groups is H or R=C n H 2n+1 and n is in the range of 1 to 10), and combinations thereof.

[0012] Optionally, the selective polymer layer further comprises a CO2-philic ether, a cross-linking agent, graphene oxide, carbon nanotubes, or a combination thereof.

[0013] In some embodiments, the support layer may comprise a gas-permeable polymer such as a polymer selected from polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, nitrile-based polymers, polymeric organosilicones, fluorinated polymers, polyolefins, copolymers thereof, and blends thereof.

[0014] In some embodiments, the support layer can include a gas-permeable polymer disposed on a base. The base can include a nonwoven fabric, such as a nonwoven fabric including fibers formed from polyester.

[0015] Membranes can be constructed in flat plate, spiral wound (SW), hollow fiber, or plate and frame configurations.

[0016] In some embodiments, the membrane can be selectively permeable to acid gases, for example, the membrane is selectively permeable to a fluid selected from the group consisting of carbon dioxide, hydrogen sulfide, sulfur dioxide, sulfur trioxide, nitric oxide, hydrogen chloride, water, and combinations thereof.

[0017] In some embodiments, the selective polymer layer can have a CO:N selectivity of at least 50 at 57° C. and 4 bar feed pressure (e.g., a CO:N selectivity of 50-500 at 57° C. and 4 bar feed pressure, 50-350 at 57° C. and 4 bar feed pressure, 100-500 at 57° C. and 4 bar feed pressure, or 100-350 at 57° C. and 4 bar feed pressure).

[0018] Also described herein are methods for separating a first gas from a feed gas stream. These methods can include contacting a membrane described herein with a feed gas stream containing the first gas under conditions effective to cause transmembrane permeation of the first gas. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 shows the chemical structures of PVAm, PZEA-Sar, and PZC. [Figure 2] FIG. 1 shows a 400 MHz 13C NMR spectrum of PEG obtained using DO as solvent. [Figure 3] 1 is a plot showing the IR spectrum of PEG. [Figure 4]1 is a plot showing the CO 2 / N 2 separation performance of membranes containing 20 wt % PZEA-Sar, 20 wt % PZC, and various contents of PEG, the balance being PVAm. [Figure 5] 1 is a plot showing the CO2 / N2 separation performance of membranes containing 6 wt% PVAm, 40-70 wt% PZEA-Sar, and the balance PEG. [Figure 6A] FIG. 1 shows the design of a cross-flow SW element. [Figure 6B] 1 is a schematic diagram of the open layout of the center tube and the glue pattern of the membrane leaves, with the epoxy glue lines labeled. [Figure 7] 1 is a plot showing CO2 permeability and CO2 / N2 selectivity of a commercial-sized, 8-inch diameter prototype SW-type module with polyguanidine-containing membranes using simulated flue gas at 77°C. 1 = simulated flue gas (20% CO2); 2 = simulated NGCC flue gas (4.1% CO2); 3 = simulated coal flue gas (13% CO2). [Figure 8A] This photo shows a coal-fired boiler at the Center for Applied Energy Research (CAER) at the University of Kentucky. [Figure 8B] 1 is a photograph showing a membrane test unit. [Figure 9] 1 is a plot showing CO2 permeability and CO2 / N2 selectivity of a commercial size 8 inch diameter prototype SW type module with polyguanidine-containing membrane using actual 77°C flue gas. [Figure 10] This is the piping and instrumentation diagram (P&ID) for the integrated bench skid. [Figure 11A] FIG. 1 shows a counter-flow SW element design for using retentate recycle as a sweep gas. [Figure 11B] 1 is a schematic diagram of the open layout of the central tube and the glue pattern of the membrane leaves. [Figure 12A] A is a photograph showing the front and side views of the first stage module. [Figure 12B] B is a photograph showing the front and side views of the second stage module. [Figure 13A] 1 is a photograph showing an integrated bench skid. [Figure 14] 1 is a plot showing CO2 capture and CO2 purity from a 500 hour bench skid test using simulated coal flue gas. DETAILED DESCRIPTION OF THE INVENTION

[0020] Disclosed herein is a membrane comprising a support layer and a selective polymer layer disposed (e.g., coated) on the support layer. The selective polymer layer can comprise a polymer matrix comprising a polyguanidine polymer.

[0021] Also provided are methods of making these membranes and methods of using these membranes.

[0022] definition As used in this 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 pharmaceutical carrier" includes mixtures of two or more such carriers, and the like.

[0023] Ranges can be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, it will be understood that by using the antecedent "about," the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values ​​disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. When a numerical value is disclosed, it is understood that "less than or equal to," "greater than or equal to," and the possible ranges between values ​​are also disclosed, as appropriately understood by one of ordinary skill in the art. For example, if the value "10" is disclosed, then "less than or equal to 10" as well as "greater than or equal to 10" is also disclosed. It is also understood that throughout this application, data is provided in several different formats, and that this data represents endpoints and starting points, as well as ranges for any combination of the data points. For example, if a specific data point "10" and a specific data point 15 are disclosed, it is understood that greater than, greater than, less than, less than, less than, and equal to 10 and 15, as well as values ​​between 10 and 15, are considered disclosed. It is also understood that each value between two specified values ​​is disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0024] 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.

[0025] "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event or circumstance occurs and cases where it does not occur.

[0026] The term "n-membered" (where n is an integer) generally refers to the number of ring-forming atoms in a moiety where n is the number of ring-forming atoms. For example, piperidinyl is an example of a 6-membered heterocycloalkyl ring, pyrazolyl is an example of a 5-membered heteroaryl ring, pyridyl is an example of a 6-membered heteroaryl ring, and 1,2,3,4-tetrahydro-naphthalene is an example of a 10-membered cycloalkyl group.

[0027] As used herein, the phrase "optionally substituted" means unsubstituted or substituted. As used herein, the term "substituted" means that a hydrogen atom has been removed and replaced with a substituent. It is understood that substitution at a given atom is limited by valence.

[0028] Throughout the definition, "C n~m " denotes a range inclusive of the endpoints, where n and m are integers and indicate the number of carbons. For example, C 1~4 , C 1~6 Examples include:

[0029] As used herein, "C" when used alone or in combination with other terms n~m The term "alkyl" refers to a saturated hydrocarbon group having n to m carbons, which may be straight-chained or branched. Examples of alkyl moieties include, but are not limited to, chemical groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, and higher homologs such as 2-methyl-1-butyl, n-pentyl, 3-pentyl, n-hexyl, and 1,2,2-trimethylpropyl. In some embodiments, alkyl groups contain 1 to 6 carbon atoms, 1 to 4 carbon atoms, 1 to 3 carbon atoms, or 1 to 2 carbon atoms.

[0030] As used herein, "C n~m"Alkenyl" refers to an alkyl group having one or more carbon-carbon double bonds and having n to m carbons. Exemplary alkenyl groups include, but are not limited to, ethenyl, n-propenyl, isopropenyl, n-butenyl, sec-butenyl, and the like. In some embodiments, the alkenyl moiety contains 2 to 6, 2 to 4, or 2 to 3 carbon atoms.

[0031] As used herein, "C n~m "Alkynyl" refers to an alkyl group having one or more carbon-carbon triple bonds and having n to m carbons. Exemplary alkynyl groups include, but are not limited to, ethynyl, propyn-1-yl, propyn-2-yl, and the like. In some embodiments, the alkynyl moiety contains 2 to 6, 2 to 4, or 2 to 3 carbon atoms.

[0032] As used herein, "C" when used alone or in combination with other terms n~m The term "alkylene" refers to a divalent alkyl linking group having n to m carbons. Examples of alkylene groups include, but are not limited to, ethane-1,2-diyl, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, butane-1,3-diyl, butane-1,2-diyl, 2-methylpropane-1,3-diyl, and the like. In some embodiments, the alkylene moiety contains 2 to 6, 2 to 4, 2 to 3, 1 to 6, 1 to 4, or 1 to 2 carbon atoms.

[0033] As used herein, "C" when used alone or in combination with other terms means n~m The term "alkoxy" refers to a group of formula -O-alkyl, where the alkyl group has n to m carbons. Exemplary alkoxy groups include methoxy, ethoxy, propoxy (e.g., n-propoxy and isopropoxy), tert-butoxy, and the like. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0034] As used herein, "Cn~m The term "alkylamino" refers to a group of formula -NHalkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0035] As used herein, "C n~m The term "alkoxycarbonyl" refers to a group of formula -C(O)O-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0036] As used herein, "C n~m The term "alkylcarbonyl" refers to a group of formula -C(O)-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0037] As used herein, "C n~m The term "alkylcarbonylamino" refers to a group of formula -NHC(O)-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0038] As used herein, "C n~m The term "alkylsulfonylamino" refers to a group of formula -NHS(O)-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0039] As used herein, the term "aminosulfonyl" refers to a group of formula -S(O)2NH2.

[0040] As used herein, "C n~mThe term "alkylaminosulfonyl" refers to a group of formula -S(O)NH(alkyl), where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0041] As used herein, "di(C n~m The term "(alkyl)aminosulfonyl" refers to a group of formula -S(O)N(alkyl), where each alkyl group independently has n to m carbon atoms. In some embodiments, each alkyl group independently has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0042] As used herein, the term "aminosulfonylamino" refers to a group of formula -NHS(O)2NH2.

[0043] As used herein, "C n~m The term "alkylaminosulfonylamino" refers to a group of formula -NHS(O)NH(alkyl), where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0044] As used herein, "di(C n~m The term "NHS(O)N(alkyl)aminosulfonylamino" refers to a group of formula -NHS(O)N(alkyl), where each alkyl group independently has n to m carbon atoms. In some embodiments, each alkyl group independently has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0045] As used herein, the term "aminocarbonylamino," employed alone or in combination with other terms, refers to a group of formula -NHC(O)NH2.

[0046] As used herein, "C n~mThe term "alkylaminocarbonylamino" refers to a group of formula -NHC(O)NH(alkyl), where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0047] As used herein, "di(C n~m The term "NHC(O)N(alkyl)aminocarbonylamino" refers to a group of formula -NHC(O)N(alkyl), where each alkyl group independently has n to m carbon atoms. In some embodiments, each alkyl group independently has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0048] As used herein, "C n~m The term "alkylcarbamyl" refers to a group of formula -C(O)-NH(alkyl), where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0049] As used herein, the term "thio" refers to a group of formula -SH.

[0050] As used herein, "C n~m The term "alkylsulfinyl" refers to a group of formula -S(O)-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0051] As used herein, "C n~m The term "alkylsulfonyl" refers to a group of formula -S(O)-alkyl, where the alkyl group has n to m carbon atoms. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0052] As used herein, the term "amino" refers to a group of formula -NH2.

[0053] As used herein, the term "aryl," used alone or in combination with other terms, refers to an aromatic hydrocarbon group that can be monocyclic or polycyclic (e.g., having 2, 3, or 4 fused rings). n~m The term "aryl" refers to an aryl group having n to m ring carbon atoms. Examples of aryl groups include phenyl, naphthyl, anthracenyl, phenanthrenyl, indanyl, indenyl, and the like. In some embodiments, an aryl group has from 6 to about 20 carbon atoms, from 6 to about 15 carbon atoms, or from 6 to about 10 carbon atoms. In some embodiments, an aryl group is substituted or unsubstituted phenyl.

[0054] As used herein, the term "carbamyl" refers to a group of formula -C(O)NH2.

[0055] As used herein, the term "carbonyl," employed alone or in combination with other terms, refers to a -C(=O)- group, which may also be written as C(O).

[0056] As used herein, "di(C n~m The term "-N(alkyl)amino" refers to a group of formula -N(alkyl), where each of the two alkyl groups independently has n to m carbon atoms. In some embodiments, each alkyl group independently has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0057] As used herein, "di(C n~m The term "(-alkyl)carbamyl" refers to a group of formula -C(O)N(alkyl), where each of the two alkyl groups independently has n to m carbon atoms. In some embodiments, each alkyl group independently has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0058] As used herein, the term "halo" refers to F, Cl, Br, or I. In some embodiments, halo is F, Cl, or Br. In some embodiments, halo is F or Cl.

[0059] As used herein, "C n~m "Haloalkoxy" refers to a group of the formula -O-haloalkyl having n to m carbon atoms. An exemplary haloalkoxy group is OCF. In some embodiments, the haloalkoxy group is only fluorinated. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0060] As used herein, "C" when used alone or in combination with other terms means n~m The term "haloalkyl" refers to an alkyl group having from 1 halogen atom up to 2s+1 halogen atoms, which may be the same or different, where "s" is the number of carbon atoms in the alkyl group, and the alkyl group has n to m carbon atoms. In some embodiments, the haloalkyl group is exclusively fluorinated. In some embodiments, the alkyl group has 1 to 6, 1 to 4, or 1 to 3 carbon atoms.

[0061] As used herein, the term "cycloalkyl" refers to a non-aromatic cyclic hydrocarbon, including cyclized alkyl and / or alkenyl groups. Cycloalkyl groups can include monocyclic or polycyclic (e.g., having 2, 3, or 4 fused rings) groups, and spirocycles. Cycloalkyl groups can have 3, 4, 5, 6, 7, 8, 9, or 10 ring-forming carbons (C 3~10). Ring-forming carbon atoms of a cycloalkyl group may be optionally substituted with oxo or sulfido (e.g., C(O) or C(S)). Cycloalkyl groups also include cycloalkylidenes. Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptenyl, cyclohexenyl, cyclohexadienyl, cycloheptatrienyl, norbornyl, norpinyl, norcarnyl, and the like. In some embodiments, a cycloalkyl is cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, or adamantyl. In some embodiments, a cycloalkyl has 6 to 10 ring-forming carbon atoms. In some embodiments, a cycloalkyl is adamantyl. The definition of cycloalkyl also includes moieties having one or more aromatic rings fused (i.e., having a common bond) to the cycloalkyl ring, for example, benzo or thienyl derivatives of cyclopentane, cyclohexane, and the like. Cycloalkyl groups containing fused aromatic rings can be attached through any ring-forming atom, including a ring-forming atom of the fused aromatic ring.

[0062] As used herein, "heteroaryl" refers to a monocyclic or polycyclic aromatic heterocycle having at least one heteroatom ring member selected from sulfur, oxygen, and nitrogen. In some embodiments, the heteroaryl ring has 1, 2, 3, or 4 heteroatom ring members independently selected from nitrogen, sulfur, and oxygen. In some embodiments, any ring-forming N in the heteroaryl moiety can be an N-oxide. In some embodiments, the heteroaryl has 5 to 10 ring atoms and 1, 2, 3, or 4 heteroatom ring members independently selected from nitrogen, sulfur, and oxygen. In some embodiments, the heteroaryl has 5 to 6 ring atoms and 1 or 2 heteroatom ring members independently selected from nitrogen, sulfur, and oxygen. In some embodiments, the heteroaryl is a 5- or 6-membered heteroaryl ring. A 5-membered heteroaryl ring is a heteroaryl having a ring with 5 ring atoms, wherein one or more (e.g., 1, 2, or 3) ring atoms are independently selected from N, O, and S. Exemplary 5-membered heteroaryls are thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4-thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-triazolyl, 1,3,4-thiadiazolyl, and 1,3,4-oxadiazolyl. A 6-membered heteroaryl ring is a heteroaryl having a ring with 6 ring atoms, wherein one or more (e.g., 1, 2, or 3) ring atoms are independently selected from N, O, and S. Exemplary 6-membered heteroaryls are pyridyl, pyrazinyl, pyrimidinyl, triazinyl, and pyridazinyl.

[0063] As used herein, "heterocycloalkyl" refers to a non-aromatic monocyclic or polycyclic heterocycle having one or more ring-forming heteroatoms selected from O, N, or S. Heterocycloalkyl includes monocyclic 4-, 5-, 6-, and 7-membered heterocycloalkyl groups. Heterocycloalkyl groups can also include spirocycles. Exemplary heterocycloalkyl groups include pyrrolidin-2-one, 1,3-isoxazolidin-2-one, pyranyl, tetrahydrofuran, oxetanyl, azetidinyl, morpholino, thiomorpholino, piperazinyl, tetrahydrofuranyl, tetrahydrothienyl, piperidinyl, pyrrolidinyl, isoxazolidinyl, isothiazolidinyl, pyrazolidinyl, oxazolidinyl, thiazolidinyl, imidazolidinyl, azepanyl, benzazapene, and the like. The ring-forming carbon atoms and heteroatoms of a heterocycloalkyl group may be optionally substituted with oxo or sulfido (e.g., C(O), S(O), C(S), or S(O)). A heterocycloalkyl group can be bonded through a ring-forming carbon atom or a ring-forming heteroatom. In some embodiments, a heterocycloalkyl group contains 0 to 3 double bonds. In some embodiments, a heterocycloalkyl group contains 0 to 2 double bonds. Also included within the definition of heterocycloalkyl are moieties having one or more aromatic rings fused (i.e., having a common bond) to a cycloalkyl ring, e.g., benzo or thienyl derivatives such as piperidine, morpholine, and azepine. Heterocycloalkyl groups containing fused aromatic rings can be bonded through any ring-forming atom, including a ring-forming atom of the fused aromatic ring. In some embodiments, a heterocycloalkyl has 4 to 10, 4 to 7, or 4 to 6 ring atoms, contains 1 or 2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and has one or more oxidized ring members.

[0064] In certain places, definitions or embodiments refer to certain rings (e.g., azetidine ring, pyridine ring, etc.). Unless otherwise specified, these rings can be bonded to any ring member as long as the valence of the atom is not exceeded. For example, an azetidine ring can be bonded at any position on the ring, while a pyridin-3-yl ring is bonded at the 3-position.

[0065] The term "compound," as used herein, is meant to include all stereoisomers, geometric isomers, tautomers, and isotopes of the structures depicted. Compounds herein identified by name or structure as one particular tautomeric form are intended to include other tautomeric forms unless otherwise specified.

[0066] The compounds provided herein also include tautomeric forms. Tautomeric forms result from the migration of a proton, which causes a single bond to swap with an adjacent double bond. Tautomeric forms include prototropic tautomers, which are isomeric protonation states with the same empirical formula and total charge. Exemplary prototropic tautomers include ketone-enol pairs, amide-imidic acid pairs, lactam-lactim pairs, enamine-imine pairs, and cyclic forms in which protons can occupy more than one position in a heterocyclic ring system, such as 1H- and 3H-imidazole, 1H-, 2H-, and 4H-1,2,4-triazole, 1H- and 2H-isoindole, and 1H- and 2H-pyrazole. Tautomeric forms may exist in equilibrium or may be sterically locked into one form by appropriate substitution.

[0067] In some embodiments, the compounds described herein may contain one or more asymmetric centers and thus exist as racemates and racemic mixtures, enantiomerically enriched mixtures, single enantiomers, individual diastereomers, and diastereomeric mixtures (e.g., including (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, (+) (dextrorotatory) forms, (-) (levorotatory) forms, racemic mixtures thereof, and other mixtures thereof). Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomeric forms of these compounds, and mixtures thereof, are expressly included in this description. The compounds described herein may also or may further contain bonds in which bond rotation is restricted about that particular bond (e.g., restrictions caused by the presence of a ring or double bond (e.g., a carbon-carbon bond, a carbon-nitrogen bond, e.g., an amide bond)). Thus, all cis / trans and E / Z isomers and rotational isomers are expressly included in this description. Unless otherwise stated or specified, the chemical name of a compound encompasses the mixture of all possible stereochemically isomeric forms of that compound.

[0068] Optical isomers can be obtained in pure form by standard procedures known to those skilled in the art, including, but not limited to, diastereomeric salt formation, kinetic resolution, and asymmetric synthesis. See, e.g., Jacques et al., Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen, SH, et al., Tetrahedron 33:2725 (1977); Eliel, EL Stereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); Wilen, SH Tables of Resolving Agents and Optical Resolutions p. 268 (EL Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, IN, 1972), each of which is incorporated herein by reference in its entirety. It is also understood that the compounds described herein include all possible regioisomers and mixtures thereof, which can be obtained in pure form by standard separation procedures known to those skilled in the art, including, but not limited to, column chromatography, thin layer chromatography, and high performance liquid chromatography.

[0069] film The membranes described herein may include a support layer and a selective polymer layer disposed (e.g., coated) on the support layer. The selective polymer layer may include a polymer matrix containing a polyguanidine polymer. Optionally, the polymer matrix may further include a hydrophilic polymer, an amine-containing polymer, or a combination thereof. In some embodiments, the selective polymer layer may further include a mobile carrier (e.g., a guanidine-based mobile carrier, an amine-based mobile carrier, or a combination thereof) dispersed in the polymer matrix. Optionally, the selective polymer layer may further subsequently include a CO2-philic ether, graphene oxide, carbon nanotubes, or a combination thereof dispersed in the polymer matrix.

[0070] support layer The support layer can be formed from any suitable material. The material used to form the support layer can be selected based on the end use application of the membrane. In some embodiments, the support layer can include a gas-permeable polymer. The gas-permeable polymer can be a crosslinked polymer, a phase-separated polymer, a porous condensation polymer, or a blend thereof. Examples of suitable gas-permeable polymers include polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, nitrile-based polymers, polymeric organosilicones, fluorinated polymers, polyolefins, copolymers thereof, or blends thereof. Specific examples of polymers that may be present in the support layer include polydimethylsiloxane, polydiethylsiloxane, polydi-isopropylsiloxane, polydiphenylsiloxane, polyethersulfone, polyphenylsulfone, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polyamide, polyimide, polyetherimide, polyetheretherketone, polyphenylene oxide, polybenzimidazole, polypropylene, polyethylene, partially fluorinated, perfluorinated, or sulfonated derivatives thereof, copolymers thereof, or blends thereof. In some embodiments, the gas-permeable polymer may be polysulfone or polyethersulfone. Optionally, the support layer may contain inorganic particles to increase mechanical strength without changing the permeability of the support layer.

[0071] In certain embodiments, the support layer can include a gas-permeable polymer disposed on a base. The base can be any shape configured to facilitate the formation of a membrane suitable for use in a particular application. For example, the base can be a flat disk, a tube, a spiral, or a hollow fiber base. The base can be formed from any suitable material. In some embodiments, the layer can include a fibrous material. The fibrous material in the base can be a mesh (e.g., a metal or polymer mesh), a woven or nonwoven fabric, glass, fiberglass, resin, or a screen (e.g., a metal or polymer screen). In certain embodiments, the base can include a nonwoven fabric (e.g., a nonwoven fabric including fibers formed from polyester).

[0072] Selective polymer layer The selective polymer layer may include a polymer matrix containing a polyguanidine polymer. Optionally, the polymer matrix may further include a hydrophilic polymer, an amine-containing polymer, or a combination thereof. In some embodiments, the selective polymer layer may further include a mobile carrier (e.g., a guanidine-based mobile carrier, an amine-based mobile carrier, or a combination thereof) dispersed in the polymer matrix. Optionally, the selective polymer layer may further subsequently include a CO2-philic ether, graphene oxide, carbon nanotubes, or a combination thereof dispersed in the polymer matrix.

[0073] In some cases, the selective polymer layer can be a polymer matrix permeable to gases by diffusion or facilitated diffusion. The selective polymer layer can include a polymer matrix having a CO:N selectivity of at least 10 at 57°C and a feed pressure of 4 bar. For example, the polymer matrix can include a CO:N selectivity of at least 25 (e.g., at least 50, at least 75, at least 100, at least 125, at least 150, at least 175, at least 200, at least 225, at least 250, at least 275, at least 300, at least 325, at least 350, at least 375, at least 400, at least 425, at least 450, or at least 475) at 57°C and a feed pressure of 4 bar. In some embodiments, the polymer matrix may have a CO:N selectivity of 500 or less (e.g., 475 or less, 450 or less, 425 or less, 400 or less, 375 or less, 350 or less, 325 or less, 300 or less, 275 or less, 250 or less, 225 or less, 200 or less, 175 or less, 150 or less, 125 or less, 100 or less, 75 or less, 50 or less, or 25 or less) at 57° C. and 4 bar feed pressure.

[0074] In certain embodiments, the selective polymer layer can include a polymer matrix having a CO:N selectivity ranging from any of the minimum values ​​described above to any of the maximum values ​​described above. For example, in certain embodiments, the selective polymer layer can include a polymer matrix having a CO:N selectivity of 10-500 at 57° C. and 4 bar feed pressure (e.g., 10-400 at 57° C. and 4 bar feed pressure, 75-400 at 57° C. and 4 bar feed pressure, 100-400 at 57° C. and 4 bar feed pressure, 10-350 at 57° C. and 4 bar feed pressure, 75-350 at 57° C. and 4 bar feed pressure, 100-350 at 57° C. and 4 bar feed pressure, 10-250 at 57° C. and 4 bar feed pressure, 75-250 at 57° C. and 4 bar feed pressure, or 100-250 at 57° C. and 4 bar feed pressure). The CO2:N2 selectivity of a selective polymer can be measured using standard methods for measuring gas permeability known in the art, such as those described in the Examples below.

[0075] polymer matrix The polymer matrix may include a polyguanidine polymer. Optionally, the polymer matrix may further include a hydrophilic polymer, an amine-containing polymer, or a combination thereof.

[0076] In certain embodiments, the polymer matrix can include a polyguanidine polymer and a hydrophilic polymer. In certain embodiments, the polymer matrix can include a polyguanidine polymer and an amine-containing polymer. In certain embodiments, the polymer matrix can include a polyguanidine polymer, a hydrophilic polymer, and an amine-containing polymer.

[0077] Polyguanidine polymers can function as "anchoring carriers" or "anchoring site carriers." Polyguanidine polymers can have any suitable molecular weight. For example, polyguanidine polymers can have a weight average molecular weight of 5,000 Da to 5,000,000 Da, or 50,000 Da to 2,000,000 Da.

[0078] Examples of polyguanidine polymers include, but are not limited to, polyethylene guanidine, polytrimethylene guanidine, polytetramethylene guanidine, polypentamethylene guanidine, polyhexamethylene guanidine, polyheptamethylene guanidine, polyoctamethylene guanidine, polyethylene N-methylguanidine, polytrimethylene N-methylguanidine, polytetramethylene N-methylguanidine, polypentamethylene N-methylguanidine, polyhexamethylene N-methylguanidine, polyheptamethylene N-methylguanidine, polyoctamethylene N-methylguanidine, polyethylene N,N'-dimethylguanidine, Poly(N-vinylguanidine), poly(N-allylguanidine), poly(N-butylguanidine), poly(N-pentylguanidine), poly(N-hexylguanidine), poly(N-heptylguanidine), poly(N-octylguanidine), copolymers thereof, and blends thereof.

[0079] Polyethyleneguanidine (PEG) can be synthesized from the polycondensation of guanidine hydrochloride (GH) and ethylenediamine (EDA) as follows: [ka] The residual product, ammonia (NH3), is removed from the polymer product.

[0080] Similarly, polytrimethyleneguanidine and polytetramethyleneguanidine can be synthesized from the polycondensation of guanidine hydrochloride with 1,3-propanediamine and 1,4-butanediamine, respectively, as shown in the following reactions: [ka]

[0081] Polypentamethylene guanidine, polyhexamethylene guanidine, polyheptamethylene guanidine, and polyoctamethylene guanidine can also be synthesized from the polycondensation of guanidine hydrochloride with 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octanediamine, respectively. Similarly, polyethylene N-methylguanidine, polytrimethylene N-methylguanidine, polytetramethylene N-methylguanidine, polypentamethylene N-methylguanidine, polyhexamethylene N-methylguanidine, polyheptamethylene N-methylguanidine, and polyoctamethylene N-methylguanidine can be prepared from the polycondensation of N-methylguanidine hydrochloride with ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octanediamine, respectively. Similarly, polyethylene N,N'-dimethylguanidine, polytrimethylene N,N'-dimethylguanidine, polytetramethylene N,N'-dimethylguanidine, polypentamethylene N,N'-dimethylguanidine, polyhexamethylene N,N'-dimethylguanidine, polyheptamethylene N,N'-dimethylguanidine, and polyoctamethylene N,N'-dimethylguanidine can be prepared from the polycondensation of N,N'-dimethylguanidine hydrochloride with ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octanediamine, respectively.

[0082] The selective polymer layer may include any suitable amount of polyguanidine polymer. For example, in some cases, the selective polymer layer may include 10% to 90% by weight (e.g., 10% to 70% by weight, 10% to 50% by weight, 20% to 50% by weight, or 10% to 30% by weight) of polyguanidine polymer, based on the total weight of the components used to form the selective polymer layer (total dry weight of the selective polymer layer).

[0083] When present, the hydrophilic polymer may have any suitable molecular weight. For example, the hydrophilic polymer may have a weight-average molecular weight of 15,000 Da to 2,000,000 Da (e.g., 50,000 Da to 200,000 Da). In some embodiments, the hydrophilic polymer may comprise polyvinyl alcohol having a weight-average molecular weight of 50,000 Da to 150,000 Da. In other embodiments, the hydrophilic polymer may be a high-molecular-weight hydrophilic polymer. For example, the hydrophilic polymer may have a weight-average molecular weight of at least 500,000 Da (e.g., at least 700,000 Da, or at least 1,000,000 Da).

[0084] The selective polymer layer can include any suitable amount of hydrophilic polymer, for example, in some cases, the selective polymer layer can include 10% to 90% by weight (e.g., 10% to 50% by weight, or 10% to 30% by weight) of hydrophilic polymer, based on the total weight of the components used to form the selective polymer layer.

[0085] When present, the amine-containing polymer may comprise any suitable amine-containing polymer. Suitable examples of amine-containing polymers include, but are not limited to, polyvinylamine (PVAm), polyallylamine, polyethyleneimine, poly-N-isopropylallylamine, poly-N-tert-butylallylamine, poly-N-1,2-dimethylpropylallylamine, poly-N-methylallylamine, poly-N,N-dimethylallylamine, poly-2-vinylpiperidine, poly-4-vinylpiperidine, polyaminostyrene, chitosan, copolymers, and blends thereof. In some embodiments, the amine-containing polymer may comprise polyvinylamine (e.g., polyvinylamine having a weight average molecular weight of 50,000 Da to 2,000,000 Da).

[0086] In some embodiments, the amine-containing polymer PVAm used is purified from a product commercially available from BASF (Vandalia, IL) under the name Polymin® VX. The PVAm can have an average molecular weight as high as 2,000 kDa. The amine-containing polymer can have a weight average molecular weight ranging from 300 to 3,000 kDa, but preferably greater than 1,000 kDa.

[0087] The selective polymer layer can include any suitable amount of amine-containing polymer, for example, in some cases, the selective polymer layer can include 10% to 90% by weight (e.g., 10% to 50% by weight, or 10% to 30% by weight) of amine-containing polymer, based on the total weight of the components used to form the selective polymer layer.

[0088] Movable Carrier In some embodiments, the selective polymer layer may further include a mobile carrier dispersed in the polymer matrix. The mobile carrier may include any molecule that functions as a "mobile carrier" for CO in the polymer matrix.

[0089] In some examples, the mobile carrier may include a guanidine-based mobile carrier, an amine-containing mobile carrier, or a combination thereof. In some embodiments, the mobile carrier may have a molecular weight of less than 1,000 Da (e.g., 800 Da or less, 500 Da or less, 300 Da or less, or 250 Da or less).

[0090] In some examples, the mobile carrier is 1,1,3,3-tetramethylguanidine, piperazine-1-carboximidamide, N-methylpiperazine-1-carboximidamide, N-ethylpiperazine-1-carboximidamide, N-propylpiperazine-1-carboximidamide, N-butylpiperazine-1-carboximidamide, N-pentylpiperazine-1-carboximidamide, N-hexylpiperazine-1-carboximidamide, N-heptylpiperazine-1-carboximidamide, N-octyl ...hexylpiperazine-1-carboximidamide, N-hexylpiperazine-1-carboximidamide, N-hexylpiperazine- Carboximidamide, 2-(1-piperazinyl)ethylamine sarcosinate, 2-(1-piperazinyl)ethylamine glycinate, 2-(1-piperazinyl)ethylamine aminoisobutyrate, piperazine sarcosinate, piperazine glycinate, piperazine aminoisobutyrate, lithium sarcosinate, lithium glycinate, lithium aminoisobutyrate, potassium sarcosinate, potassium glycinate, potassium aminoisobutyrate, amidines having the structure R1-(C=NH)-NR2R3 (wherein each of the R1, R2, and R3 groups is H or R=C n H 2n+1 where n ranges from 1 to 10), guanidines having the structure R1-N(R2)-(C=NH)-NR3R4 (where each of the R1, R2, R3, and R4 groups is H or R=C n H 2n+1 and n is in the range of 1 to 10), and combinations thereof.

[0091] Guanidine-based mobile carrier The guanidine-based mobile carrier may include any suitable compound that contains a guanidine moiety and has a molecular weight of less than 1,000 Da (e.g., 800 Da or less, 500 Da or less, 300 Da or less, or 250 Da or less). In some embodiments, the guanidine-based mobile carrier may be a water-soluble compound. In some embodiments, the guanidine-containing mobile carrier may be non-volatile at the temperature at which the membrane will be stored or used.

[0092] In some embodiments, the guanidine-based mobile carrier has the following formula I: [ka] (In the formula, R 1 and R 2 are each independently H, C 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10 cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl, 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10 Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R A or substituted with R 1 and R 2 together with the N atom to which they are attached form a 4- to 9-membered heterocycloalkyl group or a 5- to 6-membered heteroaryl group, each optionally containing 1, 2, or 3 independently selected R A substituted with a group; R 3 and R 4 are each independently H, C 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10 cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl, 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R A or substituted with R 3 and R 4 together with the N atom to which they are attached form a 4- to 9-membered heterocycloalkyl group or a 5- to 6-membered heteroaryl group, each optionally containing 1, 2, or 3 independently selected R A substituted with a group; R 5 is H, C 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10 cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl, 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 3~10 Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R A substituted with a group; Each R A are independently OH, NO2, CN, halo, C 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~4 Haloalkyl, C 1~6 Alkoxy, C 1~6 Haloalkoxy, Cyano-C 1~3 Alkyl, HO-C 1~3 Alkyl, Amino, C 1~6 Alkylamino, di(C 1~6 Alkyl)amino, thio, C 1~6 Alkylthio, C 1~6 Alkylsulfinyl, C 1~6 Alkyl sulfonyl, carbamyl, C 1~6 Alkylcarbamyl, di(C1~6 Alkyl) carbamyl, carboxy, C 1~6 Alkyl carbonyl, C 1~6 Alkoxycarbonyl, C 1~6 Alkylcarbonylamino, C 1~6 Alkyl sulfonyl amino, amino sulfonyl, C 1~6 Alkylaminosulfonyl, di(C 1~6 Alkyl)aminosulfonyl, aminosulfonylamino, C 1~6 Alkylaminosulfonylamino, di(C 1~6 Alkyl)aminosulfonylamino, aminocarbonylamino, C 1~6 Alkylaminocarbonylamino, and di(C 1~6 alkyl)aminocarbonylamino) The compound may be a compound defined by:

[0093] In some embodiments, R 1 , R 2 , R 3 , and R 4 are all C 1~4 It is alkyl (eg, methyl).

[0094] In some embodiments, R 5 is H. In other embodiments, R 5 is optionally 1, 2, 3, or 4 independently selected R A C substituted with a group 1~6 For example, R 5 is a C substituted with an OH group 1~6 C substituted with alkyl or amino groups 1~6 It may be an alkyl group.

[0095] In some instances, the guanidine-based mobile carrier is [ka] (wherein n is an integer of 1 to 12, for example, 1 to 6; TMG is tetramethylguanidine; and PZC is piperazine-1-carboximidamide). It may include one of:

[0096] Amine-containing mobile carrier Suitable amine-containing mobile carriers can include small molecules containing one or more primary amine moieties and / or one or more secondary amine moieties, such as amino acid salts.

[0097] In some embodiments, the amine-containing mobile carrier can have a molecular weight of 1,000 Da or less (e.g., 800 Da or less, 500 Da or less, 300 Da or less, or 250 Da or less). In some embodiments, the amine-containing mobile carrier can be non-volatile at temperatures at which the membrane will be stored or used. For example, the amine-containing mobile carrier can include a salt of a primary amine or a salt of a secondary amine.

[0098] In some cases, the amine-containing mobile carrier may include an amino acid salt. The amino acid salt may be a salt of any suitable amino acid. For example, the amino acid salt may be derived from glycine, arginine, lysine, histidine, 6-aminohexanoic acid, proline, sarcosine, methionine, or taurine. In some cases, the amino acid salt may be represented by the following formula: [ka] wherein, independently for each occurrence in an amino acid, each of R1, R2, R3, and R4 is selected from one of the following: [ka] or R1 and R3 together with the atoms to which they are attached form a 5-membered heterocyclic ring (when n is 1) defined by the structure below, or a 6-membered heterocyclic ring (when n is 2) defined by the structure below: [ka] The compound may include salts of the compound defined by:

[0099] Poly(amino acids), such as polyarginine, polylysine, polyonithine, or polyhistidine, may also be used to prepare amino acid salts.

[0100] In other embodiments, the amine-containing mobile carrier has the formula: [ka] (wherein R1, R2, R3, and R4 are hydrogen or a hydrocarbon group having 1 to 4 carbon atoms, n is an integer ranging from 0 to 4, and A m+ is a cation with a valence of 1 to 3) In some cases, the cation (A m+ ) is expressed as follows: [ka] wherein R5 and R6 are hydrogen or a hydrocarbon group having 1 to 4 carbon atoms, R7 is hydrogen or a hydrocarbon group having 1 to 4 carbon atoms, or an alkylamine of 2 to 6 carbon atoms and 1 to 4 nitrogen atoms, y is an integer ranging from 1 to 4, and m is an integer equal to the valence of the cation. In some embodiments, A m+ is a metal cation selected from Groups Ia, IIa, and IIIa of the Periodic Table of Elements or transition metals. For example, A m+ may include lithium, aluminum, or iron.

[0101] Other suitable amine-containing mobile carriers include aminoisobutyric acid potassium salt, aminoisobutyric acid lithium salt, aminoisobutyric acid piperazine salt, glycine potassium salt, glycine lithium salt, glycine piperazine salt, dimethylglycine potassium salt, dimethylglycine lithium salt, dimethylglycine piperazine salt, piperazine-2-carboxylic acid potassium salt, piperazine-2-carboxylic acid lithium salt, piperazine-2-carboxylic acid-piperazine salt, piperazine-4-carboxylic acid potassium salt, piperazine-4-carboxylic acid lithium salt, piperazine-4-carboxylic acid-piperazine salt, piperazine-3-carboxylic acid potassium salt, piperazine-3-carboxylic acid lithium salt, piperazine-3-carboxylic acid-piperazine salt, and blends thereof.

[0102] CO2 affinity ether Optionally, the selective polymer layer may further comprise one or more CO2-affinitive ethers dispersed in the polymer matrix. The CO2-affinitive ethers may be polymers, oligomers, or small molecules containing one or more ether linkages. Examples of CO2-affinitive ethers include alcohol ethers, polyalkylene alcohol ethers, polyalkylene glycols, poly(oxyalkylene) glycols, poly(oxyalkylene) glycol ethers, and ethoxylated phenols. In one embodiment, the CO2-affinitive ether is an alkyl ethoxylate (C1-C6)-(EO) X where x is 1 to 30, and the ethoxylate is linear or branched. In some embodiments, the CO2-philic ether may include ethylene glycol butyl ether (EGBE), diethylene glycol monobutyl ether (DGBE), triethylene glycol monobutyl ether (TEGBE), ethylene glycol dibutyl ether (EGDE), polyethylene glycol monomethyl ether (mPEG), or any combination thereof.

[0103] graphene oxide Optionally, the selective polymer layer may further comprise graphene oxide dispersed in the polymer matrix.

[0104] The term "graphene" refers to a one-atom-thick layer of sp -s that is densely packed in a honeycomb crystal lattice. 2 In one embodiment, referring to a planar sheet of bonded carbon atoms, it refers to a single-walled form of graphite.

[0105] The term "graphene oxide" herein refers to functionalized graphene sheets (FGS), which are oxidized compositions of graphite. These compositions are not defined by a single stoichiometry. Rather, upon oxidation of graphite, oxygen-containing functional groups (e.g., epoxide, carboxyl, and hydroxyl groups) are introduced onto the graphite. Complete oxidation is not necessary. Functionalized graphene generally refers to graphene oxide, where the atomic carbon-to-oxygen ratio begins at approximately 2. This ratio can be increased by reaction with components in a medium, which may include a polymer, polymer monomer, resin, or solvent, and / or by application of radiant energy. As the carbon-to-oxygen ratio becomes very large (e.g., approaching 20 or greater), the chemical composition of graphene oxide approaches that of pure graphene.

[0106] The term "graphite oxide" includes "graphene oxide," which is a morphological subset of graphite oxide in the form of planar sheets. "Graphene oxide" refers to a graphene oxide material that includes either single or multiple sheets of graphite oxide. Additionally, in one embodiment, graphene oxide refers to a graphene oxide material that contains at least one single sheet in one portion and at least one multiple sheet in another portion. Graphene oxide refers to a range of possible compositions and stoichiometries. The carbon-to-oxygen ratio in graphene oxide plays a role in determining the properties of graphene oxide and any composite polymers containing graphene oxide.

[0107] The abbreviation "GO" is used herein to refer to graphene oxide, and the designation GO(m) refers to graphene oxide having a C:O ratio of approximately "m," where m ranges from 3 to about 20, inclusive. For example, graphene oxides having a C:O ratio between 3 and 20 are referred to as "GO(3)-GO(20)," where m ranges from 3 to 20, e.g., m=3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, including all decimal points in 0.1 increments therebetween, e.g., the range of values ​​from 3 to 20 includes 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, etc., up to 20. Thus, as used herein, the term GO(m) describes all graphene oxide compositions having a C:O ratio between 3 and about 20. For example, GO with a C:O ratio of 6 would be called GO(6), and GO with a C:O ratio of 8 would be called GO(8), both of which are within the definition of GO(m).

[0108] As used herein, "GO(L)" refers to low C:O graphene oxide having a C:O ratio of approximately "L," where L is less than 3, e.g., in the range from about 1 (inclusive) to 3 (inclusive), e.g., about 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, or about 2.9. In many embodiments, the GO(L) material has a C:O ratio of approximately 2. Designations for GO(L)-based materials are the same as those for GO(m) materials above, e.g., "GO(2)" refers to graphene oxide with a C:O ratio of 2.

[0109] In some embodiments, the graphene oxide can be GO(m). In some embodiments, the graphene oxide can be GO(L). In some embodiments, the graphene oxide can be nanoporous.

[0110] Other ingredients In some embodiments, the polymer matrix may further comprise a crosslinking agent. Suitable crosslinking agents for use in the polymer matrix include, but are not limited to, formaldehyde, glutaraldehyde, maleic anhydride, glyoxal, divinyl sulfone, toluene diisocyanate, trimethylol melamine, terephthalate aldehyde, epichlorohydrin, vinyl acrylate, and combinations thereof. In some embodiments, the crosslinking agent may comprise formaldehyde, glutaraldehyde, or maleic anhydride. The polymer matrix may comprise any suitable amount of crosslinking agent. For example, the polymer matrix may comprise 1 to 40 weight percent of the crosslinking agent by weight of the polymer matrix.

[0111] The polymer matrix may further comprise a base. The base may act as a catalyst to catalyze crosslinking of the polymer matrix (e.g., crosslinking between a hydrophilic polymer and an amine-containing polymer). In some embodiments, the base may remain in the polymer matrix and become part of the polymer matrix. Examples of suitable bases include potassium hydroxide, sodium hydroxide, lithium hydroxide, triethylamine, N,N-dimethylaminopyridine, hexamethyltriethylenetetraamine, potassium carbonate, sodium carbonate, lithium carbonate, and combinations thereof. In some embodiments, the base may comprise potassium hydroxide. The polymer matrix may comprise any suitable amount of base. For example, the polymer matrix may comprise 1 to 40 weight percent of the base of the polymer matrix.

[0112] The selective polymer layer further comprises carbon nanotubes dispersed in the polymer matrix. Any suitable carbon nanotubes (prepared by any suitable method or obtained from a commercial source) may be used. The carbon nanotubes may comprise single-walled carbon nanotubes, multi-walled carbon nanotubes, or a combination thereof. In some cases, the carbon nanotubes may have an average diameter of at least 10 nm (e.g., at least 20 nm, at least 30 nm, or at least 40 nm). In some cases, the carbon nanotubes may have an average diameter of 50 nm or less (e.g., 40 nm or less, 30 nm or less, or 20 nm or less). In certain embodiments, the carbon nanotubes may have an average diameter ranging from any of the minimum values ​​noted above to any of the maximum values ​​noted above. For example, the carbon nanotubes may have an average diameter of 10 nm to 50 nm (e.g., 10 nm to 30 nm, or 20 nm to 50 nm).

[0113] In some cases, the carbon nanotubes can have an average length of at least 50 nm (e.g., at least 100 nm, at least 200 nm, at least 300 nm, at least 400 nm, at least 500 nm, at least 600 nm, at least 700 nm, at least 800 nm, at least 900 nm, at least 1 μm, at least 5 μm, at least 10 μm, or at least 15 μm). In some cases, the carbon nanotubes can have an average length of 20 μm or less (e.g., 15 μm or less, 10 μm or less, 5 μm or less, 1 μm or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less).

[0114] In certain embodiments, the carbon nanotubes can have an average length ranging from any of the minimum values ​​described above to any of the maximum values ​​described above. For example, the carbon nanotubes can have an average length of 50 nm to 20 μm (e.g., 200 nm to 20 μm, or 500 nm to 10 μm).

[0115] In some cases, the carbon nanotubes may comprise unfunctionalized carbon nanotubes. In other embodiments, the carbon nanotubes may comprise sidewall-functionalized carbon nanotubes. Sidewall-functionalized carbon nanotubes are well known in the art. Suitable sidewall-functionalized carbon nanotubes can be prepared from unfunctionalized carbon nanotubes by, for example, creating defects in the sidewalls via strong acid oxidation. The defects created by the oxidizing agent can subsequently be converted to more stable hydroxyl and carboxylic acid groups. The hydroxyl and carboxylic acid groups on the acid-treated carbon nanotubes can then be coupled to reagents containing other functional groups (e.g., amine-containing reagents), thereby introducing pendant functional groups (e.g., amino groups) onto the carbon nanotube sidewalls. In some embodiments, the carbon nanotubes may comprise hydroxy-functionalized carbon nanotubes, carboxy-functionalized carbon nanotubes, amine-functionalized carbon nanotubes, or combinations thereof.

[0116] In some embodiments, the selective polymer layer may comprise at least 0.5 wt.% (e.g., at least 1 wt.%, at least 1.5 wt.%, at least 2 wt.%, at least 2.5 wt.%, at least 3 wt.%, at least 3.5 wt.%, at least 4 wt.%, or at least 4.5 wt.%) carbon nanotubes based on the total dry weight of the selective polymer layer. In some embodiments, the selective polymer layer may comprise 5 wt.% or less (e.g., 4.5 wt.% or less, 4 wt.% or less, 3.5 wt.% or less, 3 wt.% or less, 2.5 wt.% or less, 2 wt.% or less, 1.5 wt.% or less, or 1 wt.% or less) carbon nanotubes based on the total dry weight of the selective polymer layer.

[0117] The selective polymer layer may include an amount of carbon nanotubes ranging from any of the minimum values ​​described above to any of the maximum values ​​described above. For example, the selective polymer layer may include 0.5% to 5% (e.g., 1% to 3%) by weight of carbon nanotubes, based on the total dry weight of the selective polymer layer.

[0118] If desired, the selective polymer layer may be surface modified, for example, by chemical grafting, blending, or coating, to improve the performance of the selective polymer layer. For example, a hydrophobic component may be added to the selective polymer layer to change the properties of the selective polymer layer to better promote fluid selectivity.

[0119] The total thickness of each layer of the membrane can be selected so that the structure is mechanically robust but not so thick as to impair permeability. In some embodiments, the selective polymer layer can have a thickness of 50 nanometers to 5 microns (e.g., 50 nm to 2 microns, or 100 nanometers to 750 nanometers, or 250 nanometers to 500 nanometers). In some embodiments, the support layer can have a thickness of 1 micron to 500 microns (e.g., 50 to 250 microns). In some cases, the membranes disclosed herein can have a thickness of 5 microns to 500 microns.

[0120] Production method Methods of making these membranes are also disclosed herein, which may include depositing (e.g., coating) a selective polymer layer onto a support layer to form a selective layer disposed (e.g., coated) on the support layer.

[0121] Optionally, the support layer can be pretreated prior to deposition (e.g., coating) of the selective polymer layer to remove water or other adsorbed species, for example, using methods appropriate for the support and adsorbate. Examples of adsorbed species are, for example, water, alcohols, porogens, and surfactant templates.

[0122] The selective polymer layer may be prepared by first forming a coating solution containing the components of the polymer matrix (e.g., a polyguanidine polymer and one or more additional components, such as a hydrophilic polymer, an amine-containing polymer, a mobile carrier, such as a guanidine-based mobile carrier or an amine-based mobile carrier, a CO2-affine ether, graphene oxide, carbon nanotubes, a crosslinker, a basic compound, or a combination thereof) in a suitable solvent. One example of a suitable solvent is water. In some embodiments, the amount of water used will be in the range of 50% to 99% by weight of the coating solution. The coating solution may then be used to form the selective polymer layer. For example, the coating solution may be coated onto a support layer (e.g., a nanoporous gas-permeable membrane) using any suitable technique, and the solvent may be evaporated so that a non-porous membrane is formed on the substrate. Examples of suitable coating techniques include, but are not limited to, "knife coating" or "dip coating." Knife coating involves using a knife to spread a polymer solution across a flat substrate to form a thin film of polymer solution of uniform thickness, followed by evaporation of the polymer solution solvent at ambient temperature or up to about 100°C or higher to obtain a fabricated membrane. Dip coating involves contacting a polymer solution with a porous support. Excess solution is allowed to drain from the support, and the polymer solution solvent is evaporated at ambient or elevated temperature. The disclosed membranes can be formed into forms such as hollow fibers, tubes, films, sheets, and the like. In certain embodiments, the membranes are configured in flat, spiral, hollow fiber, or plate-and-frame geometries.

[0123] In some embodiments, the membrane can be heated to a temperature and for a time sufficient to cause crosslinking. In one example, a crosslinking temperature ranging from 80°C to 100°C can be used. In another example, crosslinking can occur for 1 to 72 hours. As discussed above, the resulting solution can be coated onto a support layer and the solvent can be evaporated. In some embodiments, crosslinking the polymer matrix after solvent removal can be performed at about 100°C to about 180°C, and crosslinking can occur for about 1 to about 72 hours.

[0124] To increase the water retention capacity of the membrane, an additive may be included in the selective polymer layer before forming the selective polymer layer. Suitable additives include, but are not limited to, polystyrene sulfonate-potassium salt, polystyrene sulfonate-sodium salt, polystyrene sulfonate-lithium salt, sulfonated polyphenylene oxide, alum, and combinations thereof. In one example, the additive includes polystyrene sulfonate-potassium salt.

[0125] In some embodiments, the methods for making these films are scalable to industrial levels.

[0126] How to use The membranes disclosed herein can be used to separate gaseous mixtures. For example, methods are provided for separating a first gas from a feed gas containing the first gas and one or more additional gases (e.g., at least a second gas). The methods can include contacting any of the disclosed membranes (e.g., the side containing the selective polymer) with the feed gas under conditions effective to cause transmembrane permeation of the first gas. In some embodiments, the methods can also include withdrawing a permeate containing at least the first gas from the opposite side of the membrane, where the first gas is selectively removed from the gas stream. The permeate can contain an increased concentration of at least the first gas compared to the feed stream. The term "permeate" refers to the portion of the feed stream withdrawn to the opposite or second side of the membrane, excluding other fluids, such as sweep gas or sweep liquid, that may be present on the second side of the membrane.

[0127] The membranes can be used to separate gases at any suitable temperature, including temperatures above 57°C. For example, the membranes can be used at temperatures between 57°C and 97°C. In some embodiments, a vacuum can be applied to the permeate side of the membrane to remove the first gas. In some embodiments, a sweep gas can be flowed across the permeate side of the membrane to remove the first gas. Any suitable sweep gas can be used. Examples of suitable sweep gases include, for example, air, steam, nitrogen, argon, helium, and combinations thereof.

[0128] The first gas can include an acid gas. For example, the first gas can be carbon dioxide, hydrogen sulfide, sulfur dioxide, sulfur trioxide, nitrogen oxide, or a combination thereof. In some embodiments, the membrane can be selective for carbon dioxide relative to hydrogen, nitrogen, carbon monoxide, or a combination thereof. In some embodiments, the membrane can be selective for hydrogen sulfide relative to hydrogen, nitrogen, carbon monoxide, or a combination thereof.

[0129] In certain embodiments, the first gas can include carbon dioxide and the second gas can include hydrogen. In certain embodiments, the first gas can include carbon dioxide and the second gas can include nitrogen.

[0130] The permeability of the first gas or acid gas is at least 50 GPU (e.g., 75 GPU or more, 100 GPU or more, 150 GPU or more, 200 GPU or more, 250 GPU or more, 300 GPU or more, 350 GPU or more, 400 GPU or more, 450 GPU or more, 500 GPU or more, 550 GPU or more, 600 GPU or more, 650 GPU or more, 700 GPU or more, 750 GPU or more, 800 GPU or more) at 57°C and 4 bar feed pressure. or more, 850 GPUs or more, 900 GPUs or more, 950 GPUs or more, 1000 GPUs or more, 1100 GPUs or more, 1200 GPUs or more, 1300 GPUs or more, 1400 GPUs or more, 1500 GPUs or more, 1600 GPUs or more, 1700 GPUs or more, 1800 GPUs or more, 1900 GPUs or more, 2000 GPUs or more, 2100 GPUs or more, 2200 GPUs or more, 2300 GPUs or more, or 2400 GPUs or more).

[0131] The permeability of the first gas or acid gas is 2500 GPU or less (e.g., 2400 GPU or less, 2300 GPU or less, 2200 GPU or less, 2100 GPU or less, 2000 GPU or less, 1900 GPU or less, 1800 GPU or less, 1700 GPU or less, 1600 GPU or less, 1500 GPU or less, 1400 GPU or less, 1300 GPU or less, 1200 GPU or less, 1100 GPU or less, 1000 GPU or less, 1100 GPU or less, 1200 GPU or less, 1300 GPU or less, 1400 GPU or less, 1500 GPU or less, 1600 GPU or less, 1700 GPU or less, 1800 GPU or less, 1900 GPU or less, 1900 GPU or less, 2000 GPU or less, 2100 GPU or less, 2200 GPU or less, 2300 GPU or less, 2400 GPU or less, 2500 GPU or less, 2600 GPU or less, 2700 GPU or less, 2800 GPU or less, 2900 GPU or less, 2900 GPU or less, 300 GPU or less, 3100 GPU or less, 3200 GPU or less, 3300 GPU or less, 3400 GPU or less, 3500 GPU or less, 3600 GPU or less, 3700 GPU or less, 3800 GPU or less, 3900 GPU or less, 4000 GPU or less, 4100 GPU or less, 4200 00 GPU or less, or less, 950 GPU or less, 900 GPU or less, 850 GPU or less, 800 GPU or less, 750 GPU or less, 700 GPU or less, 650 GPU or less, 600 GPU or less, 550 GPU or less, 500 GPU or less, 450 GPU or less, 400 GPU or less, 350 GPU or less, 300 GPU or less, 250 GPU or less, 200 GPU or less, 150 GPU or less, 100 GPU or less, or 75 GPU or less).

[0132] The permeability of the first gas or acid gas through the membrane can vary from any of the minimum values ​​noted above to any of the maximum values ​​noted above or even higher. For example, the permeability of the first gas or acid gas can be from 50 GPU to 1500 GPU, or even up to 3000 GPU at 57° C. and 4 bar feed pressure (e.g., from 300 GPU to 1500 GPU at 57° C., or from 500 GPU to 1500 GPU, or even 3000 GPU at 57° C. and 4 bar feed pressure).

[0133] The membranes may exhibit a first gas / second gas selectivity of at least 10 at 57° C. and 4 bar feed pressure. In some embodiments, the membranes may exhibit a first gas / second gas selectivity of up to 500 at 57° C. and 4 bar feed pressure. For example, the membranes may exhibit a first gas / second gas selectivity of 10 or more, 25 or more, 50 or more, 75 or more, 100 or more, 125 or more, 150 or more, 175 or more, 200 or more, 225 or more, 250 or more, 275 or more, 300 or more, 325 or more, 350 or more, 375 or more, 400 or more, 425 or more, 450 or more, or 475 or more at 57° C. and 4 bar feed pressure. In some embodiments, the permeability and selectivity of the membrane for the first gas or acid gas may vary at higher or lower temperatures.

[0134] By way of non-limiting illustration, examples of certain specific embodiments of the present disclosure are provided below. [Example]

[0135] overview This example describes a polyguanidine-containing membrane for separating CO from a gas stream. The polymer selective layer coated on a highly permeable nanoporous polymer support can contain, for example, polyguanidine as the anchoring site carrier, or a mixture of polyguanidine and an amine-containing polymer as the anchoring site carrier. The anchoring site carrier(s) can function as a polymer matrix for containing CO reactive small molecules as mobile carriers in the membrane, further facilitating CO transport across the membrane. An example of an amine-containing polymer is polyvinylamine. Furthermore, monosheets of porous graphene oxide were dispersed in the selective layer to reinforce the bending stiffness of the selective layer in the membrane during feed compression and vacuum suction. The exemplary membrane thus synthesized demonstrated excellent CO / N separation performance. 35m 2 An 8-inch diameter spiral-wound (SW) membrane module containing a membrane of this type was fabricated and tested on simulated and actual coal flue gas, demonstrating stable membrane performance in the presence of O2, SO2, and NO2. In addition, an integrated bench skid with two SW-type membrane modules forming a concentration cascade was also constructed, which successfully removed 91% of the CO2 in the simulated coal flue gas and concentrated it to >95% purity. Furthermore, the polymer matrix optionally contains a hydrophilic polymer, e.g., polyvinyl alcohol.

[0136] Background technology Global CO2 emissions fell 5.8% in 2020, or nearly 2 gigatonnes (Gt) of carbon dioxide. This was the largest drop ever recorded due to the COVID-19 pandemic. Despite this decline, energy-related CO2 emissions remained high at 31.5 Gt, which caused atmospheric CO2 to reach an all-time high annual average concentration of 412.5 ppm in 2020. In 2016, coal combustion still accounted for 50% of electricity supply in the United States, representing about one-third of CO2 emissions. Carbon capture and storage (CCS) could play an important role in reducing carbon dioxide emissions in the energy sector.

[0137] Retrofitting current coal-fired power plants with amine solution-based capture systems would increase electricity costs by 70–80% and incur energy losses of 25–40%. However, membranes have been demonstrated as a promising next-generation energy efficiency technology in many industrial applications, including hydrogen recovery, air separation, and natural gas sweetening. A widely used approach to polymer membrane synthesis involves coating a thin, selective polymer layer onto a nanoporous polymer support—typically an ultrafiltration membrane made from polysulfone, polyethersulfone, or polyetherimide. Numerous research efforts have been devoted to designing polymers with high CO2 permeability and appropriate CO2 / N2 selectivity. On the one hand, polar functional groups, such as ethylene oxide groups, have been incorporated to increase the physical solubility of CO2 in the polymer matrix and allow dissolved CO2 molecules to diffuse through the membrane. On the other hand, reactive functional groups and compounds have been used as carriers to reversibly react with CO2. Chemical reactions have enhanced CO2 permeation through the membrane, and this type of membrane is termed a facilitated transport membrane.

[0138] In facilitated transport membranes, amines are the most commonly utilized CO2 carriers. The reaction mechanism between CO2 and amines is illustrated in Scheme I. The reactivity of CO2 comes from the high electron deficiency of the carbon bonded to two highly electronegative oxygen atoms. In primary and secondary amines with a lone pair of electrons on the nitrogen atom, the amine acts as a nucleophile, i.e., a Lewis base, attacking the electrophilic carbonyl group on CO2 to form a zwitterion. The zwitterion rapidly equilibrates to the corresponding carbamic acid, which is then deprotonated by another amine to form a more stable carbamate ion, resulting in two moles of amine per mole of CO2. Many successful experiments have been reported by exploring various amine structures, resulting in highly CO2-selective membranes with significant CO2 permeabilities.

[0139] Scheme I. Reaction between amines and CO2: Zwitterionic mechanism. [ka]

[0140] Although the amine structure can be further fine-tuned to enhance the CO2-loading capacity, such as by using sterically hindered polyvinylamine membranes, there are other CO2-reactive carriers worth exploring. One promising candidate is guanidine, a class of strong organic bases. The guanidine group possesses high electron density due to efficient resonance stabilization of the charges of its three amino groups attached to the carbon center. This feature can be exploited for efficient CO2 fixation, as shown in Scheme II.

[0141] Scheme II. Reaction between guanidine, CO2, and H2O via the bicarbonate mechanism. [ka]

[0142] Guanidine, as a nucleophile, can attack the electron-deficient carbon center of CO₂ to form a zwitterion. However, the zwitterion is unstable, likely due to steric hindrance from the other two amino groups, and then undergoes further hydrolysis to bicarbonate in the presence of water. The bicarbonate reaction mechanism results in one mole of CO₂ per mole of guanidine, which is highly effective for CO₂ sorption in guanidine-containing membranes.

[0143] This example describes the preparation of a polymeric membrane containing polyguanidine for CO separation from a gas stream. The polymer selective layer coated on a highly permeable nanoporous polymer support can contain polyguanidine as the anchoring site carrier, or a mixture of polyguanidine and an amine-containing polymer as the anchoring site carrier. The anchoring site carrier(s) can function as a polymer matrix for containing CO reactive small molecules as mobile carriers in the membrane. Both the anchoring sites and the mobile carriers (if present) facilitate CO transport across the membrane. Additionally, porous graphene oxide monosheets were dispersed in the selective layer to reinforce the bending stiffness of the selective layer in the membrane during feed compression and vacuum application. Furthermore, the polymer matrix optionally contains a hydrophilic polymer, such as polyvinyl alcohol. This membrane can exhibit excellent CO / N separation performance.

[0144] Materials and Methods Materials. 2-(1-piperazinyl)ethylamine (PZEA, 99%), sarcosine (Sar, 98%), piperazine-1-carboximidamide, ethylenediamine (EDA, ≥99%), and heavy water (DO, 99.9 atom % D) were purchased from Sigma-Aldrich (Milwaukee, WI). Piperazine-1-carboximidamide (PZC, 99%) was purchased from VWR (Radnor, PA). Guanidine hydrochloride (GH, 99+%) and single-layer graphene oxide (GO) in the form of solid flakes were obtained from TCI America (Portland, OR). Strongly basic anion exchange resin (Puroite® A600OH) was a gift from Puroite Corp. (Bala Cynwyd, PA). All chemicals, except for GO, were used as received without further purification. For gas permeation measurements, pre-purified CO2 and argon were purchased from Praxair Inc. (Danbury, CT).

[0145] Preparation of nanoporous graphene oxide (GO). GO was dispersed in water (approximately 1 mg / ml) using a sonication probe at 2500 W power for 3 hours. To prevent GO precipitation, KOH solution (50 wt%) was slowly added to the GO dispersion at a KOH to GO weight ratio of 14:1. The mixture was sonicated for an additional 30 minutes. After this, the water was evaporated in a convection oven at 60 °C, followed by further drying overnight in a vacuum oven at 60 °C. The resulting solid was annealed at 200 °C for 2 hours to create pores on the basal plane of the GO. After heat treatment, the solid was washed with deionized water under vacuum filtration until the filtrate reached a pH of 7. The purified nanoporous GO (nGO) was re-dispersed in water (approximately 1 mg / ml) using a sonication bath.

[0146] Preparation of Coating Solution and Membrane. nGO-reinforced composite membranes were synthesized by using the following procedure.

[0147] First, the purified PVAm solution was concentrated to 4 wt % by evaporating water at 50 °C under a nitrogen purge. Aiming for a 1.5 wt % nGO loading in the final total solids of the coating solution, an nGO dispersion at a concentration of approximately 1 mg / mL was added dropwise to the polymer solution under vigorous stirring using a 10 μL glass capillary tube. The mixture was transferred to a 15 mL conical centrifuge tube, where it was homogenized with a 1 / 8 inch microtip sonication probe at 50% amplitude until uniformly dispersed. Sonication was performed in an ice bath. The water introduced by the nGO dispersion was evaporated using a nitrogen purge.

[0148] The amino acid salt mobile carriers were synthesized by reacting a base (PZEA) with an amino acid (Sar). A stoichiometric amount of Sar was added to a 24 wt% aqueous solution of PZEA with vigorous mixing. The solution was mixed at room temperature for 2 hours before use. The chemical structures of PVAm, PZEA-Sar, and PZC are shown in Figure 1.

[0149] A certain amount of mobile carrier solution containing the amino acid salt and / or PZC was incorporated into the dispersion to form a coating solution. After centrifugation at 8,000 × g for 3 minutes to remove any air bubbles and / or particulates, the coating solution was coated onto a nanoporous polyethersulfone (PES) substrate using a GARDCO adjustable micrometer film applicator (Paul N. Gardner Company, Pompano Beach, FL) with a controlled gap setting. PES substrates with a surface average pore size of 35 nm were synthesized in-house. Ideally, to form a defect-free selective layer with a thickness of approximately 170 nm, the coating solution should have a viscosity >1100 cp with a total solids content of <15 wt%. The membranes were allowed to dry at room temperature for at least 6 hours in a fume hood before testing.

[0150] Gas Permeation Measurement. The transport properties of the composite membranes were measured by using a gas permeation apparatus. The synthesized membranes were placed in a 2.7 cm 2 gas permeation chamber inside a temperature-controlled oven (Bemco Inc. Simi Valley, CA). 2The membrane was loaded into a stainless steel rectangular permeation cell with an active area of ​​100 μm. The membrane was supported by a sintered stainless steel plate with an average pore size of 100 μm. A dry feed gas of 100 sccm containing 20% ​​CO2 and 80% N2 was used. The mixed gas was achieved by mixing two gas streams of CO2 and N2, each controlled by two mass flow controllers. The feed gas was fully saturated with water vapor by bubbling 100 mL of water through a 500 mL stainless steel humidifier (Swagelok, Westerville, OH) filled with 60% by volume Raschig rings. The humidifier temperature was controlled at 57 °C, which is the typical temperature of flue gases exiting a flue gas desulfurization (FGD) unit. However, higher temperatures, e.g., 77 °C, may also be used. The feed pressure was controlled between 1 and 5 atmospheres (absolute) by a pressure regulator close to atmospheric pressure. After the moisture was knocked out by a condenser at room temperature, the outlet gas was sent to an Agilent 6890N gas chromatograph (GC, Agilent Technologies, Palo Alto, CA) for compositional analysis. The GC was equipped with a thermal conductivity detector and a SUPELCO Carboxen® 1004 Micropack GC column (Sigma-Aldrich, St. Louis, MO).

[0151] The permeate side of the permeate cell was connected to an Ebara MD1 vacuum diaphragm pump (Ebara Technologies, Inc., Sacramento, CA). The permeate pressure was precisely controlled between 0.1 and 0.9 atmospheres by a vacuum regulator (VC, Alicat Scientific, Inc., Tucson, AZ). Before the permeate stream entered the vacuum pump, it was passed through a 1 L stainless steel water knockout vessel cooled to 0 °C by a condenser (Fisher Scientific, Hampton, NH) to remove moisture. 30 sccm of dry argon was used to transport the vacuum pump effluent to a GC for compositional analysis.

[0152] Example 1. Synthesis of polyethyleneguanidine from guanidine hydrochloride and ethylenediamine. Polyethylene guanidine (PEG) was synthesized by the polycondensation of guanidine hydrochloride (GH) and EDA under a dry nitrogen atmosphere. Prior to synthesis, a 50 mL three-necked round-bottom reaction flask connected to a distillation apparatus was dried by heating via immersion in a 100 °C oil bath for 1 hour. After cooling to room temperature, 55 mmol of EDA and 50 mmol of GH were added sequentially to the reaction flask and stirred for 10 minutes. To initiate the reaction, the oil bath temperature was increased to 120 °C in 35 minutes at 1 atmosphere pressure. Subsequently, the stirring intensity was increased from medium to maximum in 20 minutes. After cooling, the reaction pressure was reduced to 10 Torr to continue the polycondensation process. Under vacuum, the oil bath temperature was slowly increased to 220 °C in 60 minutes. After maintaining at 220 °C for 10 minutes, the oil bath temperature was increased to 240 °C in 10 minutes and maintained at 240 °C for an additional 10 minutes to complete the polymerization. Finally, the reaction system was cooled to room temperature, and the polymer product was collected after releasing the vacuum. The yield of PEG calculated based on the amount of GH was 85.47%. The PEG product was ion-exchanged by using Puroite® A600OH anion exchange resin to remove the hydrochloride salt before further use.

[0153] Purified PEG 400MHz 13 The C nuclear magnetic resonance (NMR) spectrum is shown in Figure 2. Due to resonance stabilization of the guanidine group (designated as 3 at approximately 160.1 ppm), the methylene groups designated as 1 and 2 appeared at approximately 41.7 ppm and approximately 42.7 ppm, respectively, depending on how close they were to the guanidine group.

[0154] The purified PEG was also characterized by Fourier transform infrared (FTIR) spectroscopy using a Nicolet 470 FTIR spectrometer (Thermo Electron Co., Waltham, MA), which confirmed the characteristic bands of ethylguanidine, as shown in Figure 3. The characteristic -N=C- peaks of the guanidine group were observed at 1600 and 1660 cm. -1 The absorption band due to the NH stretching vibration of the guanidine group also appeared around 3180 cm -1 It was observed near 2900cm-1 The nearby CH stretching band was not clearly identified and may have overlapped with the NH stretching band.

[0155] Static light scattering (SLS) experiments were performed on the PEG product, which indicated a molecular weight of 2.09 MDa.

[0156] Example 2. Membranes containing 20 wt% PZEA-Sar, 20 wt% PZC, and various contents of PEG, balance PVAm. In this example, a mobile carrier containing PZEA-Sar and PZC was incorporated into PEG. All membranes contained 40 wt% of the mobile carrier, with a weight ratio of PZEA-Sar to PZC of 1:1. Various contents of PVAm and PEG were incorporated into the membranes as both an anchoring site carrier and a polymer matrix to accommodate the mobile carrier.

[0157] The aforementioned membranes were tested at 77 °C, 4 atm feed pressure, and 0.4 atm vacuum pressure. The transport results are shown in Figure 4. As can be seen, as the PEG content increased from 45 wt% to 55 wt%, the CO2 permeability increased from 2211 GPU to 3643 GPU. Correspondingly, the CO2 / N2 selectivity increased from 107 to 144. The improved CO2 / N2 separation performance was attributed to the higher content of guanidine groups in the membrane, which were more effective in promoting CO2 transport than the primary amino groups in PVAm.

[0158] Example 3. Membrane containing 6 wt% PVAm, 40-70 wt% PZEA-Sar, and the remainder PEG This example demonstrates the effect of incorporating an amino acid salt mobile carrier, PZEA-Sar, into membranes on membrane separation performance. This was demonstrated by a series of membranes containing 6 wt% PVAm, 40–70 wt% PZEA-Sar, and the remainder PEG; these membranes contained no PZC. As shown in Figure 5, as the PZEA-Sar content increased from 40 wt% to 50 wt%, the CO2 permeability increased from 4005 GPU to 4203 GPU. Further increases in PZEA-Sar reduced the CO2 permeability. At 70 wt% PZEA-Sar, the membrane exhibited a CO2 permeability of only 3811 GPU, which was attributed to the reduced guanidine content and the weakened membrane matrix due to the lack of polymer moieties. In comparison, the CO2 / N2 selectivity was less affected by the PZEA-Sar content. All membranes exhibited CO2 / N2 selectivities in the range of 150–170. Overall, the optimized membrane (6 wt% PVAm, 44 wt% PEG, and 50 wt% PZEA-Sar) exhibited a maximum CO2 permeability of 4203 GPU with a CO2 / N2 selectivity of 161. This membrane was used as the benchmark for the following examples.

[0159] Example 4. Testing of a commercial-sized 8-inch diameter prototype SW-type module with a polyguanidine-containing membrane using simulated flue gas. A spiral-wound (SW) module was fabricated with a scaled-up membrane containing PEG as a fixed-site carrier along with a mobile carrier. The membrane composition was detailed in Example 3 as a benchmark membrane. The module had a commercial size of 8 inches in diameter and 22 inches in length. The SW membrane element contained 41 membrane leaves (each 20 inches wide and 36 inches long) with a total membrane area of ​​35 m. 2 As shown in Figures 6A-6B, the feed gas was introduced into one end of the SW element and the retentate exited the other end. A vacuum was applied to the permeate side to draw the permeate gas into the central tube, resulting in a cross-flow pattern.

[0160] The fabricated SW-type membrane module was tested for approximately 200 hours at 77°C using simulated flue gas containing 20.0% CO, 48.4% N, 15.0% O, 16.6% H, 3 ppm SO, and 3 ppm NO. The feed and permeate pressures were controlled at 2.5 and 0.8 atm, respectively. This set of conditions was designated Condition 1. The module was then tested for approximately 400 hours using simulated natural gas combined cycle (NGCC) flue gas containing 4.1% CO (Condition 2) and for approximately 500 hours using simulated coal-derived flue gas containing 13% CO (Condition 3). Under these two simulated flue gases, the feed pressure was increased to 4 atm. Two cycles of test conditions 2 and 3 were then alternated, resulting in a total test time of 2,000 hours. As shown in Figure 7, the module exhibited an average CO2 permeability of 4217 GPU and a CO2 / N2 selectivity of 171, remaining stable for approximately 2000 hours. This is believed to be the highest permeability / selectivity combination membrane performance for carbon capture from flue gas. Thus, a commercial-sized, 8-inch diameter prototype SW-type membrane module was successfully fabricated.

[0161] Example 5. Testing of a commercial-sized 8-inch diameter prototype SW-type module with polyguanidine-containing membrane using actual coal-derived flue gas. A commercial-sized 8-inch diameter SW-type membrane module as described in Example 3 was also tested on actual coal flue gas at the University of Kentucky's Center for Applied Energy Research (CAER). Ohio bituminous coal was burned in a 58 kW boiler at CAER, as shown in Figure 8A. On average, the coal flue gas was found to contain, on a dry basis, 9.4% CO, 78.5% N, 12.1% O, 11 ppm SO, and 22 ppm NO after the flue gas desulfurization unit. x This flue gas was then subsequently filtered through 5 μm and 1 μm filters to remove particulate matter. A caustic polisher containing 20 wt. % NaOH (aq.) was then used to remove SO and NO. xThe concentration of β-glucan was reduced to <1 ppm. The pretreated flue gas, fully saturated with water vapor at 77°C and a feed pressure of 4 atmospheres, was then passed through a membrane test unit as shown in Figure 8B. A vacuum of 0.8 atmospheres was applied on the permeate side.

[0162] During a 100-hour continuous test using actual coal flue gas at CAER, a commercial-sized, 8-inch diameter SW-type membrane module demonstrated an average CO permeability of 4269 GPU and a CO / N selectivity of 165 (FIG. 9). Although relatively large fluctuations in the feed CO concentration were observed approximately 60 hours into the test, no degradation in performance was observed throughout the test. Thus, the membranes disclosed in this invention are suitable for decarbonizing coal flue gas and have the potential for future process scale-up.

[0163] Example 6. Bench-skid testing of a two-stage membrane process containing a commercial-sized 8-inch diameter prototype SW-type module with a polyguanidine-containing membrane in countercurrent operation in the first stage using simulated coal flue gas. In this example, a bench-scale, two-stage membrane skid was constructed to demonstrate 90% CO2 capture from simulated coal flue gas with >95% CO2 purity. The piping and instrumentation diagram (P&ID) of the bench skid is shown in Figure 10. The simulated flue gas slipstream (Stream 1) enters a SO2 scrubber containing 20% ​​aqueous NaOH to reduce SO2 to 3 ppm. Pretreated flue gas (Stream 2) is compressed to approximately 3.7 atm by Compressor 1. This stream (Stream 3) enters Humidifier 1, which ensures full saturation of the flue gas with water vapor at 77°C. Humidifier 1 is also connected to a pressure buffer tank with a backpressure regulator, which controls the pressure at 3.6 atm. The 0.1 atm (approximately 1.5 psi) pressure head compared to the designed 3.5 atm feed pressure accounts for the pressure loss across Membrane Module 1 (the first-stage module). The pressurized flue gas (stream 4), if any heat loss occurs, is finally regulated by heater 1 and enters membrane module 1 as feed (stream 5). On the retentate side of this membrane module (stream 6), a first mass flow controller recycles a portion of the pressurized retentate as an internal sweep (stream 8). The remaining retentate is discharged by a second mass flow controller (stream 7), which ultimately controls the overall flue gas flow rate. The permeate of this membrane module (stream 9) contains some moisture from the water permeation. The moisture content is in excess of membrane module 2. Therefore, some of the moisture is knocked out by cooler (stream 10) and knockout 1 (stream 11).

[0164] Stream 11 is then repressurized to 3.7 atmospheres by Compressor 2 (Stream 12), cooled to 77°C, and humidified by Humidifier 2 (Stream 13). A pressure buffer tank, or Knockout 1, is also connected to Humidifier 2, and the pressure is controlled at 3.6 atmospheres. This stream is reheated by Heater 2 (Stream 14) in case of any heat loss, and fed to Membrane Module 2 (the second-stage module). The pressurized retentate (Stream 15) is discharged by a mass flow controller, which ultimately controls the feed flow rate. This stream is ultimately recycled to Stream 2. The permeate (Stream 16) is drawn off at 0.7 atmospheres by Vacuum Pump 1. The discharge of Vacuum Pump 1 (Stream 17) is dehumidified by Knockout 2 and then discharged (Stream 18).

[0165] The first stage module was based on a SW-type membrane module as described in Example 4, which contained 41 membrane leaves, each 20 inches wide and 36 inches long, for a total membrane area of ​​35 m. 2However, to use the partially recycled retentate as a sweep gas, a counterflow configuration was used, as shown in Figures 11A-11B. The feed gas (i.e., flue gas) entered the SW element through a feed spacer, while the sweep in the retentate recycle operation was first sent to the element through a central tube and then distributed through the permeate spacer. To ensure uniform distribution of the permeate sweep flow and avoid "dead zones" near the edges of the membrane leaves, we developed epoxy glue dot lines with a strategically designed pattern to reduce pressure drop and achieve a counterflow configuration, as shown in Figure 11B. The distance between the glue dot lines and the internal glue lines on the membrane leaves was set to 1.5 inches on the sweep inlet side and 2.5 inches on the sweep outlet side to accommodate the additional flow of permeate. The diameter of the glue dots was 0.25 inches. The spacing between two glue dots was set to 0.5 inches in the first 12-inch portion of the membrane leaf, 1 inch in the middle 12-inch portion of the membrane leaf, and 1.5 inches in the last 12-inch portion of the membrane leaf to achieve a more uniform distribution of the sweep flow across these three portions of the membrane leaf.

[0166] The second stage module was a cross-flow pattern, essentially the same as that in Example 4. However, in this stage only 14 membrane leaves were required, resulting in a total membrane area of ​​12 m. 2 Thus, the diameter was reduced to 5 inches. The fabricated first and second stage modules are shown in Figures 12A-12B. A photograph of the integrated bench skid is shown in Figure 13.

[0167] The integrated bench skid was tested at 77 °C using simulated coal flue gas containing 13.0% CO, 55.4% N, 15.0% O, 16.6% H, 3 ppm SO, and 3 ppm NO. As shown in Figure 14, the CO recovery was 91.0 ± 0.6%, and the CO purity (dry basis) was 95.5 ± 0.3%. The trace components in the CO product included 4.5% N, 9 ppm O, 13 ppm SO, and 11 ppm NO, all on a dry basis. The concentrations of these trace components met the standards for CO transportation through carbon steel pipelines (i.e., 4-5% N, <10 ppm O, <100 ppm SO, and <100 ppm NO). x ). The separation performance of the skid remained stable during the 500-hour test. This example demonstrates not only the good stability of both the membrane module and the two-stage membrane process, but also the capture targets of >90% CO2 capture and >95% CO2 purity.

[0168] References [1] International Energy Agency, CO2emissions-Global energy review 2021, available at https: / / www.iea.org / reports / global-energy-review-2021 / co2-emissions (accessed 3 / 1 / 2022). [2] V. Andreoni, S. Galmarini, Drivers in CO2emissions variation: A decomposition analysis for 33 world countries, Energy, 103 (2016) 27-37. [3] J. Black, Cost and Performance Baseline for Fossil Energy Plants Volume 1: Bituminous Coal and Natural Gas to Electricity Final report, 2nd ed., National Energy Technology Laboratory, November, 2010. [4]W.S.W. Ho, K.K. Sirkar, Membrane Handbook, Chapman & Hall, New York, 1992, Kluwer Academic Publishers, Boston, reprint edition, 2001。 [5]Y. Chen, B. Wang, L. Zhao, P. Dutta, W.S.W. Ho, New Pebax® / zeolite Y composite membranes for CO2 capture from flue gas, J. Membr. Sci., 495 (2015) 415 - 423. Sci., 495 (2015) 415 - 423。 [6]W. Yave, A. Car, J. Wind, K.-V. Peinemann, Nanometric thin film membranes manufactured on square meter scale: Ultra-thin films for CO2 capture, Nanotechnology, 21 (2010) 395301。 [7]W. Yave, A. Car, S.S. Funari, S.P. Nunes, K.-V. Peinemann, CO2-philic polymer membrane with extremely high separation performance, Macromolecules, 43 (2009) 326 - 333。 [8]Y. Han, W.S.W. Ho, Recent advances in membranes for CO2 capture, Chin. J. Chem. Eng., 26 (2018) 2238 - 2254. [9]Y. Han, W.S.W. Ho, Polymeric membranes for CO2 separation and capture”, J. Membr. Sci., 628 (2021), 119244。

[10] P. Danckwerts, The reaction of CO2 with ethanolamines, Chem. Eng. Sci., 34 (1979) 443 - 446。

[11] Y.Han,D.Wu,W.S.W.Ho,Simultaneous effects of temperature and vacuum and feed pressures on facilitated transport membrane for CO2 / N2separation,J.Membr.Sci.,573(2019)476-484。

[12] Y.Han,D.Wu,W.S.W.Ho,Nanotube-reinforced facilitated transport membrane for CO2 / N2separation with vacuum operation,J.Membr.Sci.,567(2018)261-271。

[13] Y.Chen,W.S.W.Ho,High-molecular-weight polyvinylamine / piperazine glycinate membranes for CO2capture from flue gas,J.Membr.Sci.,514(2016)376-384。

[14] Y.Chen,L.Zhao,B.Wang,P.Dutta,W.S.W.Ho,Amine-containing polymer / zeolite Y composite membranes for CO2 / N2separation,J.Membr.Sci.,497(2016)21-28。

[15] Z.Tong,W.S.W.Ho,New sterically hindered polyvinylamine membranes for CO2separation and capture,J.Membr.Sci.,543(2017)202-211。

[16] T.-Y.Chen,X.Deng,L.-C.Lin,W.S.W.Ho,New sterically hindered polyvinylamine-containing membranes for CO2capture from flue gas,J.Membr.Sci.,645,120195(2022)。

[17] R. Pang, KKChen, Y. Han, WSWHo, Highly permeable polyethersulfone substrates with bicontinuous structure for composite membranes in CO2 / N2 separation, J. Membr. Sci., 612(2020), 118443.

[18] P. Shirley, P. Myles, Quality Guidelines for Energy System Studies: CO2Impurity Design Parameters, National Energy Technology Laboratory, January 2019

[0169] The compositions, systems, and methods of the appended claims are not limited in scope by the specific compositions, systems, and methods described herein, which are intended as illustrations of certain aspects of the claims. Any functionally equivalent compositions, systems, and methods are intended to be within the scope of the claims. Various modifications of the compositions, systems, and methods in addition to those shown and described herein are intended to be within the scope of the appended claims. Furthermore, although only certain representative compositions, systems, and method steps disclosed herein have been specifically described, other combinations of such compositions, systems, and method steps are also intended to be within the scope of the appended claims, even if not specifically recited. Thus, although combinations of steps, elements, components, or components may be explicitly referred to herein, other combinations of steps, elements, components, and components are included, even if not explicitly stated.

[0170] As used herein, the term "comprising" and variations thereof are used synonymously with the term "including" and variations thereof and are open-ended, non-limiting terms. Although the terms "comprising" and "including" have been used herein to describe various embodiments, the terms "consisting essentially of" and "consisting of" may be used in place of "comprising" and "including" to provide more specific embodiments of the present invention, and are disclosed. Unless otherwise specified, all numerical values ​​expressing shapes, dimensions, and the like used in the specification and claims should be understood to be, at a minimum, not to limit the application of the doctrine of equivalents to the scope of the claims, and should be understood to be interpreted in light of the number of significant digits and ordinary rounding approaches.

[0171] 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 disclosed invention belongs. Publications and the materials for which they are cited herein are specifically incorporated by reference.

Claims

1. The supporters and a selective polymer layer disposed on the support layer; A membrane comprising: the selective polymer layer comprises a polymer matrix comprising a polyguanidine polymer; The membrane.

2. The polyguanidine polymer is selected from the group consisting of polyethylene guanidine, polytrimethylene guanidine, polytetramethylene guanidine, polypentamethylene guanidine, polyhexamethylene guanidine, polyheptamethylene guanidine, polyoctamethylene guanidine, polyethylene N-methylguanidine, polytrimethylene N-methylguanidine, polytetramethylene N-methylguanidine, polypentamethylene N-methylguanidine, polyhexamethylene N-methylguanidine, polyheptamethylene N-methylguanidine, polyoctamethylene N-methylguanidine, polyethylene N,N'-dimethylguanidine, polytrimethylene 2. The membrane of claim 1, wherein the polyisoprene is selected from N,N'-dimethylguanidine, polytetramethylene N,N'-dimethylguanidine, polypentamethylene N,N'-dimethylguanidine, polyhexamethylene N,N'-dimethylguanidine, polyheptamethylene N,N'-dimethylguanidine, polyoctamethylene N,N'-dimethylguanidine, poly(N-vinylguanidine), poly(N-allylguanidine), poly(N-butylguanidine), poly(N-pentylguanidine), poly(N-hexylguanidine), poly(N-heptylguanidine), poly(N-octylguanidine), copolymers thereof, and blends thereof.

3. The membrane of any of claims 1 to 2, wherein the polyguanidine polymer comprises polyethylene guanidine (PEG).

4. The membrane of any of claims 1 to 3, wherein the polyguanidine polymer is present in the selective polymer layer in an amount of 10% to 70% by weight, based on the total dry weight of the selective polymer layer.

5. The membrane of any of claims 1 to 4, wherein the polymer matrix further comprises a hydrophilic polymer, an amine-containing polymer, or a combination thereof.

6. 6. The membrane of claim 5, wherein the amine-containing polymer is selected from the group consisting of polyvinylamine, polyallylamine, polyethyleneimine, poly-N-isopropylallylamine, poly-N-tert-butylallylamine, poly-N-1,2-dimethylpropylallylamine, poly-N-methylallylamine, poly-N,N-dimethylallylamine, poly-2-vinylpiperidine, poly-4-vinylpiperidine, polyaminostyrene, chitosan, copolymers, and blends thereof.

7. The membrane of claim 6 , wherein the amine-containing polymer comprises polyvinylamine.

8. 8. The membrane of any one of claims 5 to 7, wherein the hydrophilic polymer comprises a polymer selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyethylene oxide, polyvinylpyrrolidone, polyacrylamine, polyamine, such as polyallylamine, polyvinylamine, or polyethyleneimine, polysiloxane, copolymers thereof, and blends thereof.

9. The membrane of any of claims 1 to 8, wherein the selective polymer layer further comprises a mobile carrier dispersed in the polymer matrix.

10. 10. The membrane of claim 9, wherein the mobile carrier comprises a guanidine-based mobile carrier, an amine-containing mobile carrier, or a combination thereof.

11. The membrane according to any one of claims 9 to 10, wherein the mobile carrier has a molecular weight of less than 1,000 Da.

12. The guanidine-based mobile carrier is represented by the following formula I 【Chemical 1】 (In the formula, R １ and R ２ are each independently H, C １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl; １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R Ａ group or R １ and R ２ together with the N atom to which they are attached form a 4- to 9-membered heterocycloalkyl group or a 5- to 6-membered heteroaryl group, each optionally containing 1, 2, or 3 independently selected R Ａ substituted with a group; R ３ and R ４ are each independently H, C １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl; １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R Ａ group or R ３ and R ４ together with the N atom to which they are attached form a 4- to 9-membered heterocycloalkyl group or a 5- to 6-membered heteroaryl group, each optionally containing 1, 2, or 3 independently selected R Ａ substituted with a group; R ５ is H, C １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl; １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C ３～１０ Cycloalkyl, 6- to 10-membered aryl, 5- to 10-membered heteroaryl, and 4- to 10-membered heterocycloalkyl optionally contain 1, 2, 3, or 4 independently selected R Ａ substituted with a group; Each R Ａ are independently OH, NO ２ , CN, Halo, C １～６ Alkyl, C ２～６ Alkenyl, C ２～６ Alkynyl, C １～４ Haloalkyl, C １～６ Alkoxy, C １～６ Haloalkoxy, cyano-C １～３ Alkyl, HO-C １～３ Alkyl, amino, C １～６ Alkylamino, di(C １～６ alkyl) amino, thio, C １～６ Alkylthio, C １～６ Alkylsulfinyl, C １～６ Alkyl sulfonyl, carbamyl, C １～６ Alkylcarbamyl, di(C １～６ alkyl) carbamyl, carboxy, C １～６ Alkylcarbonyl, C １～６ Alkoxycarbonyl, C １～６ Alkylcarbonylamino, C １～６ Alkyl sulfonyl amino, amino sulfonyl, C １～６ Alkylaminosulfonyl, di(C １～６ alkyl)aminosulfonyl, aminosulfonylamino, Ｃ１～６ Alkylaminosulfonylamino, di(C １～６ alkyl)aminosulfonylamino, aminocarbonylamino, C １～６ Alkylaminocarbonylamino, and di(C １～６ alkyl) aminocarbonylamino) The membrane according to any one of claims 9 to 11, comprising a compound defined by:

13. R １ , R ２ , R ３ , and R ４ All are C １～４ The membrane of claim 12, wherein the alkyl group is alkyl.

14. R １ , R ２ , R ３ , and R ４ The membrane of claim 13, wherein all of

15. R ５ The membrane according to any one of claims 12 to 14, wherein is H.

16. R ５ optionally 1, 2, 3, or 4 independently selected R Ａ C substituted with a group １～６ The membrane according to any one of claims 12 to 14, wherein the alkyl group is alkyl.

17. R ５ is substituted with an OH group １～６ 17. The membrane of claim 16, wherein the alkyl is alkyl.

18. R ５ is substituted with an amino group １～６ The membrane of claim 16 , wherein the alkyl is alkyl.

19. The guanidine-based mobile carrier is 【Chemistry 2】 wherein n is an integer from 1 to 12, for example, 1 to 6; TMG is tetramethylguanidine; and PZC is piperazine-1-carboximidamide. The membrane according to any one of claims 10 to 18, comprising one of:

20. 20. The membrane of any of claims 10 to 19, wherein the guanidine-based mobile carrier is selected from the group comprising tetramethylguanidine, piperazine-1-carboximidamide, or a combination thereof.

21. The membrane of any of claims 10 to 20, wherein the amine-containing mobile carrier comprises a salt of a primary amine or a salt of a secondary amine.

22. The amine-containing mobile carrier compound has the general formula: 【Chemistry 3】 (In the formula, R １ , R ２ , R ３ , and R ４ is hydrogen or a hydrocarbon group having 1 to 4 carbon atoms, n is an integer ranging from 0 to 4, and A ｍ＋ is a cation having a valence of 1 to 3, and m is an integer equal to the valence of the cation. The membrane of any one of claims 10 to 21, comprising a salt defined by:

23. 23. The membrane of any of claims 10 to 22, wherein the amine-containing mobile carrier comprises a salt selected from the group consisting of aminoisobutyric acid potassium salt, aminoisobutyric acid lithium salt, aminoisobutyric acid piperazine salt, glycine potassium salt, glycine lithium salt, glycine piperazine salt, dimethylglycine potassium salt, dimethylglycine lithium salt, dimethylglycine piperazine salt, piperazine-2-carboxylic acid potassium salt, piperazine-2-carboxylic acid lithium salt, piperazine-2-carboxylic acid piperazine salt, piperazine-4-carboxylic acid potassium salt, piperazine-4-carboxylic acid lithium salt, piperazine-4-carboxylic acid piperazine salt, piperazine-3-carboxylic acid potassium salt, piperazine-3-carboxylic acid lithium salt, piperazine-3-carboxylic acid piperazine salt, and blends thereof.

24. The membrane of any of claims 10 to 23, wherein the amine-containing mobile carrier comprises an amino acid salt.

25. The amino acid salt is represented by the following formula: 【Chemistry 4】 wherein, independently for each occurrence in said amino acid, each of R1, R2, R3, and R4 is selected from one of the following: 【Chemistry 5】 or R1 and R3 together with the atoms to which they are attached form a 5-membered heterocyclic ring (when n is 1) defined by the structure below, or a 6-membered heterocyclic ring (when n is 2) defined by the structure below: 【Chemistry 6】 25. The membrane of claim 24 defined by:

26. The membrane of any of claims 24 to 25, wherein the amino acid salt comprises glycinate, sarcosinate, or aminoisobutyrate.

27. The selective polymer layer is ２ The membrane of any one of claims 1 to 26, further comprising an affinity ether.

28. The CO ２ 28. The membrane of claim 27, wherein the affinity ether is selected from alcohol ethers, polyalkylene alcohol ethers, polyalkylene glycols, poly(oxyalkylene) glycols, poly(oxyalkylene) glycol ethers, ethoxylated phenols, and combinations thereof.

29. The CO ２ The affinity ether is alkyl ethoxylate (C1-C6)-(EO) Ｘ 29. The membrane of claim 28, wherein x is 1 to 30 and the ethoxylate is linear or branched.

30. The CO ２ 30. The membrane of claim 29, wherein the affinity ether is selected from ethylene glycol butyl ether (EGBE), diethylene glycol monobutyl ether (DGBE), triethylene glycol monobutyl ether (TEGBE), ethylene glycol dibutyl ether (EGDE), polyethylene glycol monomethyl ether (mPEG), poly(ethylene glycol) dimethyl ether, or any combination thereof.

31. The membrane of any of claims 1 to 30, wherein the selective polymer layer further comprises a cross-linking agent.

32. 32. The membrane of claim 31 , wherein the crosslinking agent comprises a compound selected from the group consisting of formaldehyde, glutaraldehyde, maleic anhydride, glyoxal, divinyl sulfone, toluene diisocyanate, trimethylol melamine, terephthalate aldehyde, epichlorohydrin, vinyl acrylate, and combinations thereof.

33. The membrane of any of claims 1 to 32, wherein the selective polymer layer further comprises graphene oxide dispersed in the polymer matrix.

34. 34. The film of claim 33, wherein the graphene oxide has a carbon to oxygen ratio of 3 to 20.

35. 35. The film of any of claims 33-34, wherein the graphene oxide has a carbon to oxygen ratio of 1-3.

36. 36. The membrane of any of claims 33-35, wherein the selective polymer layer comprises 0.01 wt% to 5 wt% graphene oxide, based on the total dry weight of the selective polymer layer.

37. 37. The membrane of any of claims 33 to 36, wherein the graphene oxide is nanoporous.

38. The membrane of any of claims 1 to 37, wherein the selective polymer layer further comprises carbon nanotubes dispersed in the polymer matrix.

39. The membrane of any of claims 1 to 38, wherein the support layer comprises a gas-permeable polymer.

40. 40. The membrane of claim 39, wherein the gas permeable polymer comprises a polymer selected from polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, nitrile-based polymers, polymeric organosilicones, fluorinated polymers, polyolefins, copolymers thereof, and blends thereof.

41. 41. The membrane of claim 40, wherein the gas permeable polymer comprises polyethersulfone or polysulfone.

42. The membrane of any of claims 1 to 41, wherein the support layer comprises a gas permeable polymer disposed on a base.

43. 43. The membrane of claim 42, wherein the base comprises a nonwoven fabric.

44. 44. The membrane of claim 43, wherein the nonwoven fabric comprises fibers formed from polyester.

45. 45. The membrane of any one of claims 1 to 44, wherein the membrane is configured in a flat, spiral, hollow fiber, or plate-and-frame configuration.

46. 46. ​​The membrane of any one of claims 1 to 45, wherein the membrane is selectively permeable to acid gases.

47. 47. The membrane of any one of claims 1 to 46, which is selectively permeable to a fluid selected from the group consisting of carbon dioxide, hydrogen sulfide, sulfur dioxide, sulfur trioxide, nitric oxide, hydrogen chloride, water, and combinations thereof.

48. The selective polymer layer has a CO 2 content of at least 50 at 57° C. and 4 bar feed pressure. ２ :N ２ A membrane according to any one of claims 1 to 47, having selectivity.

49. The selective polymer layer has a CO 2 content of 50-500 at 57° C. and 4 bar feed pressure, 50-350 at 57° C. and 4 bar feed pressure, 100-500 at 57° C. and 4 bar feed pressure, or 100-350 at 57° C. and 4 bar feed pressure. ２ :N ２ A membrane according to any one of claims 1 to 48, having selectivity.

50. 50. A method for separating a first gas from a feed gas stream, the method comprising contacting a membrane as defined in any one of claims 1 to 49 with the feed gas stream containing said first gas under conditions effective to cause transmembrane permeation of said first gas.

51. 51. The method of claim 50, wherein the feed gas comprises hydrogen, carbon dioxide, hydrogen sulfide, hydrogen chloride, carbon monoxide, nitrogen, methane, steam, sulfur oxides, nitrogen oxides, or combinations thereof.

52. 52. The method of any of claims 50 to 51, wherein the first gas is selected from carbon dioxide, hydrogen sulfide, hydrogen chloride, and combinations thereof.

53. the feed gas comprises a second gas selected from the group consisting of nitrogen, hydrogen, carbon monoxide, and combinations thereof; 53. The method of any one of claims 50 to 52, wherein the membrane exhibits a first gas / second gas selectivity of 50 to 500 at 57°C and a feed pressure of 4 bar.

54. 1. A method of making a membrane comprising depositing a selective polymer layer onto a support layer, said selective polymer layer comprising a polymer matrix comprising a polyguanidine polymer.

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