Patent Application
20240226802
Process-related emission from calcination accounts for the major CO2 emissions from heavy industry such as cement and steelmaking plants in the U.S. and cannot be reduced by switching fossil fuels to renewable energy. The adoption of carbon capture utilization and storage (CCUS) technologies is crucial to decarbonize cement industry. Adsorption, absorption, and membrane processing are primary CO2 capture technologies used in industry. The conventional adsorption or absorption processes require the use of energy intensive treatment facilities for sorbent and acid, which is not only slow, but also consumes a large amount of organic solvent for sorbent regeneration.
By comparison, a membrane-based process is compact and has less energy and water usage, but its treatment capacity is lower than the adsorption process due to permeability and selectivity trade-off. CO2 transportation within polymeric membranes is usually through solution-diffusion, which depends on the polymer material's intrinsic properties. High permeability has been observed for perfluoropolymers, thermally arranged polymers, and iptycene-containing polymer materials. However, this type of gas diffusion membrane has limitations in CO2 selectivity. The CO2 interactive materials, such as amine-functionalized materials (polyvinylamine, polyethyleneimine, polyallylamine materials) and ionic liquid have been shown to have improved CO2 selectivity, but their CO2 permeabilities were relatively low. Such limitations of current conventional membrane technology, as well as the high operation and capital costs required to implement the technologies has rendered them of little commercial value at manufacturing scale.
CO2 separation membranes and processes of the disclosure can provide low-cost, high-throughput on-site post combustion CO2 capture at manufacturing sites. The membranes and processes of the disclosure can be modular and compact. This can advantageously allow the technology to readily be incorporated into any CO2 intensive manufacturing processes, both at new factories and as retrofits to existing processes.
Commercially available membranes show relatively low CO2 selectivity. Current state-of-the-art membranes demonstrate improved selectivity, but cannot meet the CO2 permeance and cost requirements for commercially viable use.
A CO2 separation membrane in accordance with the disclosure can include a CO2-philic layer comprising one or more mobile CO2 carriers and one or more immobile CO2 carriers, a blended CO2-permeable and CO2-selective polymer matrix, and water adsorption nanostructures. The membrane can further include a CO2-permeance layer. The CO2-philic layer is disposed upstream of the CO2-permeance layer such that a flow of source gas to be separate enters the membrane from a feed side at which the CO2-philic layer is present and CO2 exits the membrane at a permeate side after passing through both the CO2-philic layer and the CO2-permeance layer.
Membranes in accordance with the disclosure have been observed to have improved CO2/N2 selectivity as well as CO2 permeance. The membranes utilize a composite structure having one or more CO2-philic layer, and one or more CO2 permeable layers. Referring to
The CO2-philic layer(s) and CO2 permeable layer(s) can be crosslinked to enhance the structural stability and mechanical strength of the composite membranes. The crosslinker can be, for example, trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TATM), diethylenetriamine (DETA), triethylenetetramine (TETA), perfluorinated toluene diisocyanate (PFTDI), but not limited to these materials. The use of crosslinker depends on the materials of CO2-philic layer(s) and CO2 permeable layer(s). Crosslinking can be achieved, for example, by ultraviolet (UV) curing, thermal curing, electron beam curing, and other chemical bonding methods. The CO2-philic layer(s) contains both mobile, immobile amine-based CO2 carriers, and nanostructure. The CO2-philic layer can have a thickness of about 10 nm to about 500 μm. With immobile amine-based carriers, CO2 and H2O from the feed gas side can interact with the amine groups in the membrane to form bicarbonate ion (HCO3−), which can release CO2 at the permeate side of the membrane. They can also form propylammonium carbamate ion pair [R—NH—COO][NH3R] when the amine density is high, which can better facilitate CO2 interaction. Mobile carriers such as amino acid salts react with CO2 through zwitterionic mechanism. The amino acid salt is first protonated with H2O and then interacts with CO2 to form carbamate ions (NCOO—), which transports CO2 from the feed side to the permeate side in a cycled binding-release-regeneration loop. The nanostructure such as zeolite and metal organic framework (MOF) absorbs H2O from the feed gas sides and hence increase H2O content in the membrane, facilitating amino-group protonation and CO2 interaction and transport.
The mobile amine-based CO2 carriers can be amino acid salts, amine-containing small molecules, amine-containing ionic liquids, and caronic anhydrase (CA), but are not limited to these materials. Suitable amino acid salts include, but are not limited to, Proline with potassium, potassium glycinate, lithium glycinate, potassium argininate, and piperazine glycinate. The amine-containing small molecules include ethanediamine (EDA), piperazine (PIP), monoethanolamine (MEA) and diethanol amine (DEA). Amine containing ionic liquids include, but are not limited to tetrabutylphosphonium prolinate ([P4444][Pro]) and Triethyl(2-methoxymethyl) phosphonium Indazolide [P222(101)][Inda].
Mobile carriers, such as amino acid salts can diffuse within matrix polymers and often show higher CO2 permeance than immobilized amine-functionalized CO2 carriers.
The immobile carriers can be amine-impregnated nanostructures, and amine-containing ionic liquids. Hollow or porous nanostructures are preferred due to their large surface area and pore channel effect. For example, the nanostructures can be one or more of porous silica nanospheres, hollow oxides nanospheres, porous TiO2 nanoparticles, carbon nanotubes, graphene oxides. They can also be molecular sieves such as zeolite, covalent organic frameworks (COF), and metal organic framework (MOF) structures. Additionally, these porous nanostructures can be used without amine functionalization to adsorb water vapors and facilitate amine-protonation and interaction with CO2. The nanostructures can have an effective average diameter of about 10 nm to about 1 μm. The pore size of the nanostructures or cavity size of the molecular sieves can be between 0.4 nm and 1 μm. The amine-containing ionic liquids include, but not limited to poly(1-vinyl-3-ethylimidazolium glycinate) (Poly([Veim] [Gyl]), Amine-crosslinked epoxide-amine poly(imidazolium) poly-[Im][TFSI]/1-ethyl-3-methylimidazolium dicyanamide ([EMIM] [DCA]).
The nanostructures can be optionally covalently linked to host polymers. For example, the nanostructures can be covalently linked through functionalization by plasma surface modification, grafting functional polymer molecules, and silanization. The surface functional polymer molecules and silanization agent can include, for example, but are not limited to, 3-glycidyloxypropyl trimethoxysilane (GPS), (3-Aminopropyl)triethoxysilane (APTES), Vinyltriethoxysilane (VTES), Phenyltrimethoxysilane (PTMS), (3-Methacryloxypropyl)trimethoxysilane (MPS).
Alternatively or additionally, the nanostructures can be tightly captured by the host polymers through host polymer crosslinking using small molecule activators or UV light after membrane casting. The crosslinker can be, for example, trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TATM), diethylenetriamine (DETA), trimethylolpropane (TMP), trimethylolpropane trimethacrylate (TMPTMA), hexamethylene diisocyanate (HDI), but not limited to these materials.
The host polymer can be a rubbery polymer, a polyamine, poly(ionic liquid)-type materials or blended matrix of those. Rubbery polymers can include, but are not limited to polydimethylsiloxane and polyamine/polyether elastomers such as Pebax® (ARKEMA). Polyamides can include polyvinylamine (PVAm), poly(ethyleneimine (PEI), poly(allylamine) (PAA), polyamidoamine (PAMAM) dendrimer, and chitosan. For example, the host polymer can be PVA-PEI. Poly(ionic liquid)-type materials can include Poly([Veim] [Gyl]), Amine-crosslinked poly-[Im][TFSI] epoxy resin/[Emim] [DCA], [P4444][Pro] and [P222101][Inda].
The CO2-philic layer can have a multi-layer structure. For example, the immobile and mobilized CO2 carriers can be present in separate layers, such as shown in
Where the CO2-philic layer is provided as a multiple layer structure with the mobile and immobile CO2 carriers separated in different layers of the multilayer structure, each individual layer can have a thickness of about 10 nm to about 500 μm.
The CO2-permeance layer can be an anisotropic nanofiltration or ultrafiltration membrane. The CO2-permeance layer can serve as a support layer. The CO2-permeance layer can have a thickness of about 10 μm to about 1000 μm. The CO2-permeance layer can have an average pore size of about 1 nm to about 10 μm. The CO2 permeance layer can be, for example, one or more of polymeric materials, such as, polyethersulfone (PES), polytetrafluoroethylene (PTFE), cellulose acetate, mixed cellulose ester (MCE), polycarbonate (PC), polyvinylidene fluoride (PVDF), nylon. Use of other polymer materials that can form porous structures are also contemplated herein. The CO2 permeance layer can be, for example, one or more ceramic materials, such as alumina (Al2O3), zirconia (ZrO2), titania (TiO2), silicon carbide (SiC), and glassy materials. In another case, the CO2 permeance layer can be made of metals or alloys, such as aluminum, stainless steel, and nickel-titanium. This layer can be fabricated by phase inversion induced immersion precipitation, non-solvent induced phase separation, three dimensional (3D) printing, extrusion, molding, casting, powder bed fusion, binder jetting, vat photopolymerization, stereolithography, or other similar techniques. The CO2-permeance layer can have uneven microstructures across thickness direction, e.g., the average pore size or pore morphology is different among the top, middle, and bottom sections of the permeance layer. Different microstructures provide different tortuous paths for gas molecules to travel, leading to different gas transport mechanism. The surface microstructure of the permeance layer also influences deposition, adhesion, and defect of the CO2-philic layer, which locates on top of the permeance layer. The CO2-permeance layer can be, for example, a porous nano- or micrometer fibrous membrane with large or small fiber diameter, pore size, and porosity, such as shown in
The membranes of the disclosure can have a gutter layer disposed between the CO2-philic layer and the CO2-permeance layer. The gutter layer can be one or more of rubbery polymers (such as PDMS, Pebax, PVA, polybutadiene, and chloroprene polymers), fluorinated polymers (such as fluoroelastomer, polytetrafluoroethylene (PTFE)), and glassy polymers such aspoly(1-(trimethylsilyl)-1-propyne) (PTMSP), and/or blend of two or more of those. The gutter layer can have a thickness of about 10 nm to about 500 μm. The membrane of the disclosure can have a cap layer disposed on top of the CO2-philic layer that helps defects such as pin holes. The cap layer can be one or more of rubbery polymers (such as PDMS, Pebax, PVA, polybutadiene, and chloroprene polymers), fluorinated polymers (such as fluoroelastomer, polytetrafluoroethylene (PTFE)), and glassy polymers such aspoly(1-(trimethylsilyl)-1-propyne) (PTMSP), and/or blend of two or more of those. The cap layer can have a thickness of about 10 nm to about 500 μm. The gutter layer and cap layer can be cross-linked to the neighboring layers using cross-linkers and curing methods like the ones described previously.
Methods of forming membranes of the disclosure can include coating CO2-philic layer precursor onto a CO2-permeance layer. Membranes in accordance with the disclosure can be used using various deposition methods to coat a CO2-philic layer precursor onto the CO2-permeance layer. For example, the CO2-philic layer precursor can be coated by dip-coating, spin-coating, electro-spraying, gravure coating, slot-die coating, and blade coating. For example, a roll-to-roll slot-die coating system equipped with in-line drying and curing units such as UV curing lamps, two zone dry air furnace and infrared lamps can be used. Coated membrane material curing can be achieved through a variety of thermal treatments including isothermal curing, UV irradiation, electron beam irradiation, microwave heating, RF curing, or a combination of several treatments in stage.
The CO2-philic precursor can include the mobile and immobile carriers, thereby allowing the mobile and immobile carriers to be coated in a single coating step. Alternatively, the mobile and immobile carriers can be provided in separate precursors, for example first and second precursors, can be prepared for the mobile and immobile carriers. The separate precursors can be coated sequentially to form a multilayer structure. The separate precursors can be coated sequentially or simultaneously to form gradient concentration structures. Any suitable solvents can be used in preparing the coating solutions.
Amine-functionalized porous silica nanospheres can be fabricated as the immobile carrier, for example, using several techniques. For example, small silica nanospheres of less than 50 nm diameters were fabricated by emulsion templating of poly(acrylic acid) (PAA) by NH4OH, followed by ethanol and tetraethyl orthosilicate (TEOS) treatment.
Larger silica nanospheres of size 500 nm were synthesized using cetrimonium bromide (CTAB) micelles. Firstly, CTAB was dissolved in a mixture of aqueous and ethanol solutions. Next, TEOS and ammonia were added sequentially. The mixture was then staged at moderate temperatures for extended hours (e.g., 6 h-8 h) for reaction. The nanospheres fabricated this way showed larger pore sizes as indicated by the STEM-HAADF images and EDX elemental mapping (
NH2 functionalized SiO2 nanosphere can be formed using one-step synthesis. For example, the addition of (3-Aminopropyl)triethoxysilane (APTES) in abovementioned method with CTAB can be used. Referring to
Methods of the disclosure can allow coating widths of ≥0.3 m and lengths of more than several tens meters, making this a commercially viable process for producing membranes suitable for use in industrial manufacturing plants.
Membranes of the disclosure can be used in a variety of industrial processes in which CO2 separation is beneficial. For example, the membranes can be utilized in cement production, steelmaking operation, chemical synthesis, refining, paper production, food production, core-fired power generation.
Polyvinyl alcohol (PVA) and Proline with potassium (ProK) was prepared as a single composite CO2-philic layer or a section of a bilayer composite CO2-phillic layer. ProK was a mobile-CO2 carrier. PVA was used as a polymer matrix to host ProK. An 8 wt % PVA water solution as prepared by dissolving PVA into deionized water at 80° for 4 hours. A precursor solution of 8% PVA-40% ProK was prepared by mixing 10 g of the 8 wt % PVA water solution with 0.533 g of L-proline and 0.259 KOH using a high-energy mixer operated at 3000 rpm for 10 min. KOH was added in an equal molar amount to L-proline. The percentage of ProK was calculated by following equation as 40%:
A membrane having a single composite CO2-philic layer with mobile and immobile carriers was fabricated from the precursor solution by coating the precursor solution on a commercially available porous PES membrane (served as the CO2 permeance layer in this case). For samples 1 and 2, PES membranes purchased from BTS were used, which have an average pore size of 100 nm. For samples 3 and 4, a 3M 2F and a 3M 4F PES membrane was used, respectively. A slot-die coater with a 25 mm die-head was used for the coating of the CO2-philic layer on the PES substrate directly or on PES substrate coated with a PDMS layer. The coating speed was controlled between 0.1-0.5 m/min, and the coating gap size was between 50-1000 μm, depending on the target CO2 membrane thickness. A sample was also prepared using Nylon as the CO2 permeance layer.
In samples 3 and 4, the CO2-philic layer contains a PDMS bottom section and a Prok-PVA top section for the purpose of improving CO2 permeability. The PDMS precursor was prepared by mixing a PDMS base and a curing agent with a ratio of 10:1. Then the mixed PDMS base and curing agent was diluted with toluene to a composition of 75 wt % PDMS solution versus 25 wt % toluene. The coating of PDMS was performed using a slot-die coater with 100 mm die-head. After coating the PDMS film was aged at room temperature for 4-6 hours, followed by thermal curing at 60-85C for 2-4 hours. The dry PDMS layer thickness was 400 μm and 150 μm for sample 3 and 4, respectively Prok-PVA layers were then coated on top.
After the coating, membrane sample was dried at 60° C. (for sample 1 and 2) and 80° C. (for sample 3 and 4) for 1 hour, and evaluated its CO2 separation performance. CO2 permeability and CO2/N2 selectivity was measured at 1 atm using a continuous-flow gas permeation measurement system, where the concentration of the gases that permeate through the tested membranes will be measured directly using a gas chromatograph (GC). The feed gas is a CO2—N2 mixed gas comprising of 30% CO2 and 70% N2 purchased from Airgas. Additional water moisture was introduced to the feed gas during testing to promote the CO2 reaction with the amine-based materials. The moisture content in the feed gas will be controlled by using a bubbler located in the temperature-controllable water bath, or by directly injecting moisture with a water vapor pump. Given the high solubility of CO2 in water, the saturation of CO2 in the bubbler will be maintained before measurement to ensure H2O molecules are carried by the test gas. As for the pumping method, water vapor is generated using an evaporator. Table 1 shows the compositional features of the prepared membranes and the Table 2 shows the permeance, permeability and selectivity performance results.
The samples in Table 1 have different PVA-Prok layer thickness and PDMS amount, which leads to different CO2 permeability and selectivity. The results demonstrate high CO2/N2 selectivity of amino acid salt based membrane (e.g., 171) and by adjusting CO2-philic layer structure, CO2 permeability can be improved. The overall thickness of the CO2-philic layer is high, reducing CO2 permeance. Reducing CO2-philic layer thickness or introducing porous nanostructures to improve CO2 permeance is possible.
Amine functionalized porous silica (NH2—SiO2) was incorporated into an amino acid salt containing PVA-ProK layer. The NH2—SiO2 was prepared in a one-step process for formation of the porous SiO2 and NH2-functionalization. Cetrimonium bromide (CTAB) was used as micelles template, and (3-Aminopropyl)triethoxysilane (APTES) was used as an agent for NH2-functionalization. Specially, CTAB was first dissolved into 50 ml of ethanol/water mixture with ratio of 1:3. After the CTAB was fully dissolved, 0.5 ml of tetraethyl orthosilicate (TEOS) and 0.5 ml of ammonium hydroxide was added. Finally, 0.4934 g of APTES was added (molar ratio of TEOS:ATPES is 1:4). The resulting solution was kept at room temperature for 6 hours under the stirring. The white precipitation was collected by the centrifuge. The collected powder was washed with water and ethanol for 3 times and dried at 60° C. overnight.
A precursor solution with PVA, ProK, and NH2—SiO2 was prepared for coating as part of the CO2-philic layer. The PVA solution was first prepared by dissolving 8 wt % PVA into DI water at 80° C. for 4 hours. 10 grams of this 8 wt % PVA solution was then mixed with 0.533 grams of L-proline and 0.259 grams of KOH. The KOH was added equal molar to L-proline, and percentage of ProK is calculated by the following equation as 40% of ProK:
Then, 0.16 gram of NH2—SiO2 (i.e., 20 wt % of the mass of PVA) was added. The prepared precursor solution was fully dispersed using a high-energy mixer rotating at 2500 rpm for 30 min. This resulting solution was used to coat the top layer of the bilayer composite CO2-philic layer having both mobile and immobile carriers.
The bottom layer of the bilayer CO2-philic layer is a PDMS layer. PDMS precursor was prepared by mixing a PDMS base and a curing agent with a ratio of 10:1 and then diluting the mixture with toluene (25 wt % toluene vs. 75 wt % PDMS-based mixture). The PDMS solution was then coated on a porous commercial PES membrane (e.g., 3M 4F PES or BTS PES) by slot-die coating. For this particular sample, a 100 mm die-head was used. The coating speed was set between 0.1-0.5 m/min, and the coating gap was about 1000 μm. After coating, sample was aged at room temperature for 6-10 hours followed by oven curing at 60 C for 2-4 hours. The dry PDMS layer has 400 μm thicknesss.
After the PDMS layer is fully cured. An amine-functionalized polymer layer was coated on top of PDMS. Similar coating conditions were used to coat this layer, except that the coating gap was adjusted to obtain a thinner film. After the coating, the membrane sample was dried at 60° C. for 1 hour before CO2 separation test. Dry film thickness of 5 μm was measured for the top amine-functionalized layer.
CO2 permeability and CO2/N2 selectivity was measured at 1 atm using the same test conditions as described in Example 1. Table 3 shows the compositional features of the prepared membranes and the Table 4 shows the permeance, permeability and selectivity performance results.
The results demonstrate that the addition of amine-functionalized porous silica nanospheres (NH2—SiO2) helps improve permeability.
Aspect 1. A CO2 separation membrane, comprising:
Aspect 2. The membrane of aspect 1, wherein the CO2-philic layer has a thickness of about 10 nm to about 500 μm.
Aspect 3. The membrane of aspect 1, wherein the water adsorption nanostructures comprise hollow nanostructures, or porous nanostructures, or molecular sieves.
Aspect 4. The membrane of aspect 1, wherein the blended CO2-permeable and CO2-selective polymer matrix comprise rubbery polymers, polyamine, poly(ionic liquid)-type materials, fluorinated polymers, glassy polymers, or blended matrix of those.
Aspect 5. The membrane of aspect 1, wherein the CO2-permeance layer and the CO2-philic layer are crosslinked by a polymer crosslinker.
Aspect 6. The membrane of aspect 5, wherein the crosslinker is trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TATM), diethylenetriamine (DETA), triethylenetetramine (TETA), or perfluorinated toluene diisocyanate (PFTDI).
Aspect 7. The membrane of aspect 1 or 2, wherein the mobile CO2 carriers comprise one or more amine-based mobile CO2 carriers.
Aspect 8. The membrane of aspect 7, wherein the amine-based mobile CO2 carriers comprise amine-containing small molecules, amino acid salts, amine-containing ionic liquids, and caronic anhydrase.
Aspect 9. The membrane of any one of the preceding aspects, wherein the one or more immobile CO2 carriers are amine-impregnated hollow or porous nanostructures, molecular sieves, or certain amine-containing ionic liquids.
Aspect 10. The membrane of aspect 9, wherein the amine-containing ionic liquids are one or more of poly(1-vinyl-3-ethylimidazolium glycinate) (Poly([Veim] [Gyl]), Amine-crosslinked epoxide-amine poly(imidazolium) poly-[Im][TFSI]/1-ethyl-3-methylimidazolium dicyanamide ([EMIM] [DCA]).
Aspect 11. The membrane of aspect 9, wherein the nanostructures comprise one or more of porous silica nanospheres, porous TiO2 nanoparticles, hollow oxides spheres, carbon nanotubes, graphene oxides, and molecular sieves such as zeolites, covalent organic frameworks and metal organic framework.
Aspect 12. The membrane of aspect 9 and 11, wherein the nanostructures have an effective average diameter of about 10 nm to about 1 μm, and a pore size or cavity size between 0.4 nm and 1 μm.
Aspect 13. The membrane of any one of aspects 9, 11 and 12, wherein the nanostructures are attached to a host matrix polymer.
Aspect 14. The membrane of aspect 13, wherein the nanostructures are attached to the matrix polymer through covalent linkage or tightly captured by the host polymers through host polymer crosslinking with crosslinker.
Aspect 15. The membrane of aspect 14, wherein covalent linkage is achieved by plasma surface modification, grafting functional polymer molecules, or silanization.
Aspect 16. The membrane of aspect 15, wherein functional molecules used for grafting or silanization comprises one or more materials selected from 3-glycidyloxypropyl trimethoxysilane (GPS), (3-Aminopropyl)triethoxysilane (APTES), Vinyltriethoxysilane (VTES), Phenyltrimethoxysilane (PTMS), and (3-Methacryloxypropyl)trimethoxysilane (MPS).
Aspect 17. The membrane of aspect 15, wherein the crosslinker that links the surface functionalized nanostructures and matrix is trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TATM), diethylenetriamine (DETA), trimethylolpropane (TMP), trimethylolpropane trimethacrylate (TMPTMA), or hexamethylene diisocyanate (HDI).
Aspect 18. The membrane of aspect 4, 13, 14, wherein the matrix polymer is one or more of rubbery polymers, polyamine, poly(ionic liquid)-type materials, fluorinated polymers, glassy polymers, or blended matrix of those.
Aspect 19. The membrane of aspect 17, wherein the rubbery polymers is one or more of polydimethylsiloxane (PDMS) and polyamine/polyether elastomers such as Pebax® (ARKEMA), PVA, polybutadiene, and chloroprene polymers.
Aspect 20. The membrane of aspect 17, wherein the polyamine is one or more of polyvinylamine, poly(ethyleneimine), poly(allylamine), polyamidoamine dendrimer, and chitosan.
Aspect 21. The membrane of aspect 17 wherein the poly(ionic liquid)-type materials can include poly([Veim] [Gyl]), amine-crosslinked poly-[Im][TFSI] epoxy resin/[Emim] [DCA], tetrabutylphosphonium/-prolinate ([P4444][Pro]) and triethyl(2-methoxymethyl)phosphonium in-dazole ([P222101][Inda]).
Aspect 22. The membrane of aspect 17 wherein the fluorinated polymers can include fluoroelastomer, and polytetrafluoroethylene (PTFE)
Aspect 23. The membrane of aspect 17 wherein glassy polymers include aspoly(1-(trimethylsilyl)-1-propyne) (PTMSP)
Aspect 24. The membrane of any one of the preceding aspects, wherein the CO2-philic layer has a gradient of concentration of one or both of the mobile and immobile CO2 carriers.
Aspect 25. The membrane of aspect 23, wherein the CO2-philic layer has a gradient of concentration of mobile CO2 carriers with increasing concentration of the mobile CO2 carriers from the feed side to the permeate side of the membrane.
Aspect 26. The membrane of aspect 23 or 24, wherein the CO2-philic layer has a gradient concentration of immobile CO2 carriers, with decreasing concentration of immobile CO2 carriers from the feed side to the permeate side of the membrane.
Aspect 27. The membrane of aspect 25, wherein the CO2-philic layer has a gradient concentration of mobile CO2 carriers with increasing concentration of the mobile CO2 carriers from the feed side to the permeate side of the membrane; and a gradient concentration of immobile CO2 carriers, with decreasing concentration of immobile CO2 carriers from the feed side to the permeate side of the membrane.
Aspect 28. The membrane of any one of aspects 1 to 22, wherein the CO2-philic layer has a multi-layer structure comprising a first layer comprising the immobile CO2 carriers and a second layer comprising the mobile CO2 carriers, wherein the first layer is arranged at the feed side of the membrane and the second layer is downstream of the first layer.
Aspect 29. The membrane of any one of aspects 1 to 22, wherein the CO2-philic layer has blended polymer materials and gradient compositions.
Aspect 30. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer is an anisotropic nanofiltration or ultrafiltration membrane.
Aspect 31. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer is one or more of polyethersulfone, polytetrafluoroethylene (PTFE), cellulose acetate, mixed cellulose ester (MCE) polycarbonate (PC), polyvinylidene fluoride (PVDF), and nylon.
Aspect 32. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer is ceramic.
Aspect 33. The membrane of aspect 32, wherein the ceramic is alumina (Al2O3), zirconia (ZrO2), titania (TiO2), silicon carbide (SiC), and glassy materials.
Aspect 34. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer comprises one or more metals and/or one or more metal alloys.
Aspect 35. The membrane of aspect 34, wherein the one or more metals and/metal alloys comprises one or more of aluminum, stainless steel, nickel-titanium, and alloys thereof.
Aspect 36. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer is a porous fibrous membrane.
Aspect 37. The membrane of any one of the preceding aspects, wherein the CO2-permeance is non-planar and/or a hollow tubular structure.
Aspect 38. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer has a thickness of about 10 μm to about 1000 μm.
Aspect 39. The membrane of any one of the preceding aspects, wherein the CO2-permeance layer is porous.
Aspect 40. The membrane of aspect 36 or 39, wherein the CO2-permeance layer has an average pore size of about 1 nm to about 10 μm.
Aspect 41. The membrane of any one of the preceding aspects, further comprising a gutter layer arranged between the CO2-philic layer and the CO2-permeance layer.
Aspect 42. The membrane of aspect 41, wherein the gutter layer comprises one or more of rubbery polymers, polyamine, poly(ionic liquid)-type materials, fluorinated polymers, glassy polymers, and blends thereof.
Aspect 43. The membrane of aspect 33 or 34, wherein the gutter layer has a thickness of about 10 nm to about 500 μm.
Aspect 44. The membrane of any one of the preceding aspects, further comprising a cap layer disposed on the surface of the CO2-philic layer.
Aspect 45. The membrane of aspect 44, wherein the cap layer comprises one or more of rubbery polymers, polyamine, poly(ionic liquid)-type materials, fluorinated polymers, glassy polymers, and blends thereof.
Aspect 46. The membrane of aspect 44 or 45, wherein the cap layer has a thickness of about 10 nm to about 5 μm.
Aspect 47. A method of making a membrane according to aspect 1, comprising coating a CO2-philic precursor on a CO2-permeance layer and drying or curing to form the CO2-philic layer.
Aspect 48. The method of aspect 47, wherein the CO2-philic precursor comprises both the immobile and mobile CO2 carriers.
Aspect 49. The method of aspect 48, wherein the CO2-philic precursor comprises a first precursor comprising mobile CO2 carriers and a second precursor comprising immobile CO2 carriers and the method comprises sequentially coating the CO2-permeance layer with the second precursor and then coating with the first precursor to thereby form a multilayer CO2-philic layer structure.
Aspect 50. The method of aspect 49, wherein the CO2-philic precursor comprises a first precursor comprising mobile CO2 carriers and a second precursor comprising immobile CO2 carriers and the method comprises coating the CO2-permeance layer with the first and second precursors such that the CO2-philic layer has a gradient concentration of mobile CO2 carriers with increasing concentration of the mobile CO2 carriers from the feed side to the permeate side of the membrane; and/or a gradient concentration of immobile CO2 carriers, with decreasing concentration of immobile CO2 carriers from the feed side to the permeate side of the membrane.
The foregoing description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the disclosure may be apparent to those having ordinary skill in the art.
All patents, patent applications, government publications, government regulations, and literature references cited in this specification are hereby incorporated herein by reference in their entirety. In the case of conflict, the present description, including definitions, will control.
Throughout the specification, where the compounds, compositions, methods, and/or processes are described as including components, steps, or materials, it is contemplated that the compounds, compositions, methods, and/or processes can also comprise, consist essentially of, or consist of any combination of the recited components or materials, unless described otherwise. Component concentrations can be expressed in terms of weight concentrations, unless specifically indicated otherwise. Combinations of components are contemplated to include homogeneous and/or heterogeneous mixtures, as would be understood by a person of ordinary skill in the art in view of the foregoing disclosure.
The benefit of priority to U.S. Provisional Patent Application No. 63/438,416 filed Jan. 11, 2023, the disclosure of which is incorporated herein by reference in its entirety FIELD The disclosure relates to membranes for CO2 separations and methods of making the same.
| Number | Date | Country | |
|---|---|---|---|
| 63438416 | Jan 2023 | US |
