Adsorbent material for CO2 capture, its use, and method for producing the adsorbent material.

Abstract

A method for preparing an sorbent material (3) for separating gaseous carbon dioxide from a gas mixture, preferably at least one of ambient air (1), flue gas, and biogas, wherein the gas mixture includes, in addition to the gaseous carbon dioxide, further gases other than gaseous carbon dioxide, and the separation is carried out by cyclic adsorption / desorption using an sorbent material (3) that can reversibly bind carbon dioxide and adsorb the gaseous carbon dioxide within a unit (8), wherein the sorbent material (3) comprises at least one of a primary amine portion, a secondary amine portion, and a tertiary amine portion immobilized on a solid carrier, and is prepared using an amination pathway that avoids crosslinking.

Description

[Technical Field]

[0001] The present invention relates to a carbon dioxide recovery material having a primary and / or secondary amine carbon dioxide recovery portion having good recovery and swelling properties, as well as a method for preparing such a recovery material, the use of such a recovery material, and a carbon dioxide recovery method using such a material. [Background technology]

[0002] According to the 2017 OECD report [Global Energy & CO2Status Report 2017, OECD / IEA March 2018], annual CO2 emissions into the atmosphere are approximately 32.5 Gt (gigatons, or 32.5 x 10⁻⁹ tons). As of February 2020, all but two of the 196 countries that negotiated the Paris Agreement within the framework of the United Nations Framework Convention on Climate Change (UFCCC) in 2016 have ratified it. This figure signifies a consensus on the threat of climate change and the need for global action to limit the rise in global temperature to well below 2 degrees Celsius above pre-industrial levels.

[0003] The technology and science community has been tasked with proposing solutions to achieve the goal of limiting CO2 emissions into the atmosphere and removing greenhouse gases from the atmosphere through or by a number of technologies. Flue gas capture, or CO2 capture from point sources such as specific industrial processes and specific CO2 emission sources, deals with a wide range of relatively high concentrations of CO2 (3-100 vol%) depending on the process that generates the flue gas. At high concentrations, the separation of CO2 from other gases is thermodynamically more advantageous than the separation of CO2 from low-concentration sources such as ambient air with a concentration of around 400 ppm, and consequently, economically advantageous. Nevertheless, the concept of capturing CO2 from point sources itself has strong limitations. While it is particularly well-suited to targeting such point sources, it is inherently tied to the specific location where the point source is situated, and at best can only limit emissions and support the achievement of carbon neutrality; as a technology solution, it cannot contribute to negative emissions (i.e., the permanent removal of carbon dioxide from the atmosphere) or remove past emissions. To achieve negative emissions (i.e., permanent removal of carbon dioxide from the atmosphere), the two most notable solutions currently being applied are CO2 capture using vegetation with natural photosynthesis (i.e., utilizing trees and plants, but not truly permanent removal), which is still in the early stages of development, and CO2 capture using DAC technology, which is the only truly permanent removal.

[0004] Afforestation enjoys broad public support. However, the scope and feasibility of reforestation projects are debated, and they are likely not as simple an approach as they seem, as they require a large footprint in terms of the ratio of occupied surface area to CO2 removed. On the other hand, DACs have a smaller land footprint, therefore do not compete with crop production, can permanently remove CO2 from the atmosphere, and can be deployed anywhere on Earth.

[0005] All of the above strategies for mitigating climate change hold potential and are considered as potential parts of a larger overall solution. The most likely future scenario is the deployment of multiple or diverse different approaches after further development.

[0006] Several DAC technologies are described, such as the use of alkaline earth oxides to form calcium carbonate as described in Patent Document 1. Different approaches include the use of solid CO2 adsorbents (hereinafter referred to as sorbents), typically in the form of a packed bed of sorbent particles, where CO2 is recovered at the gas-solid interface. Such sorbents may include different types of amino-functionalized polymers, such as the immobilized aminosilane sorbents reported in Patent Document 2 and the amine-functionalized cellulose disclosed in Patent Document 3.

[0007] Patent document 4 describes the use of ion exchange materials containing aminoalkylated bead polymers for removing carbon dioxide from industrial applications.

[0008] Patent Document 5 describes an sorbent for reversibly adsorbing CO2 from a gas mixture, the sorbent being composed of a polymer adsorbent having primary amino functional groups. This material can be regenerated by applying pressure or humidity fluctuations.

[0009] Several academic publications, including Non-Patent Documents 1, 2, and 3, have also examined in detail the use of cross-linked polystyrene resins functionalized with primary benzylamines as solid sorbents for DAC applications. Polystyrene-divinylbenzene resins have also been used as carriers for impregnation with amines such as tetraethylenepentamine and diethanolamine (Patent Documents 6 and 4), and this system is suitable only for desorption processes that do not involve condensation of any gas stream, such as saturated or supersaturated vapor. Patent Document 7 also shows the functionalization of polystyrene-divinylbenzene polymers with a wide variety of amines and their use in carbon recovery of gas streams containing high concentrations of CO2. However, the nitrogen content reported in Patent Document 7 is 5-10 mol / kg, which is similar to the amount achievable by functionalizing PS-DVB with benzylamine, as reported in Non-Patent Document 1. The optimal sorbent should ideally consist mainly of an active phase so as to enhance the carbon recovery process.

[0010] The amine reacts with CO2 to form a carbamate moiety, which can then be regenerated back to the original amine in the next step, for example, by raising the temperature of the sorbent bed to about 100°C, thereby releasing the CO2. An economically viable process for carbon recovery means that the sorbent has the ability to recover as much CO2 as possible in a very short time, so that the system throughput can be improved. For this purpose, this feature is of course related to the amount of active amine sites that can bind to CO2, and therefore it is very important to develop new materials with high CO2 recovery capacity. Some materials show limitations in the degree of functionalization that can be achieved, and therefore, in order to overcome this limitation, it is necessary to invent novel sorbent structures that are not trivial.

[0011] Non-patent document 5 discusses poly(ethyleneimine) (PEI) supported on pore-expanded MCM-41 whose surface is covered with a layer of long-chain alkyl, and found to be a more efficient CO2 adsorbent than PEI supported on corresponding calcined silica and all PEI-impregnated materials reported in the literature. The layer of surface alkyl chains is reported to play an important role in increasing the dispersion of PEI and thus reducing diffusion resistance. Furthermore, at low temperatures, adsorbents with relatively low PEI content were found to be more efficient than high-load sorbents because the adsorption rate increased. Extensive CO2 adsorption and desorption cycles showed that, despite limited losses due to amine evaporation, materials with enhanced stability could be obtained by using humidified feed and purge gases.

[0012] Non-patent document 6 reports the performance of a mesoporous silica-supported polyethyleneimine (PEI)-silica adsorbent for recovering CO2 from ambient air in a laboratory-scale bubbling fluidized bed (BFB) reactor. Air recovery tests were conducted in a BFB reactor for 4 to 14 days using 1 kg of PEI-silica adsorbent. Despite the low CO2 concentration in the ambient air, nearly 100% CO2 recovery efficiency was achieved with a relatively short gas-solid contact time of 7.5 seconds. The equilibrium CO2 adsorption capacity for air recovery was found to be as high as 7.3 wt%. The proposed "PEI-CFB air recovery system" primarily comprises a circulating fluidized bed (CFB) adsorbent and a BFB desorber with a CO2 recovery capacity of 40 tons-CO2 / day. Driving the air through the CFB adsorbent and suspending and circulating the solid adsorbent within the loop requires significant pressure loss, resulting in higher power requirements than other reported air recovery systems. However, the thermal energy requirement was significantly reduced by the thermal swing adsorption (TSA) technology employed for the regeneration strategy in a separate BFB desorber. The total energy required was 6.6 GJ / t-CO2, which is comparable to other reference air recovery systems.

[0013] Patent Document 8 discloses a method for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air, flue gas, and biogas, by circulating adsorption / desorption using an adsorbent material, the method comprising at least the following sequential and repeated steps (a) to (e): (a) contacting the aforementioned gas mixture with the adsorbent material to adsorb gaseous carbon dioxide; (b) isolating the aforementioned adsorbent material from the aforementioned flow-through; (c) inducing a temperature rise in the aforementioned adsorbent material; (d) extracting at least the desorbed gaseous carbon dioxide from the unit and separating the gaseous carbon dioxide from the vapor within the unit or downstream of the unit; and (e) bringing the aforementioned adsorbent material to ambient air conditions, wherein the aforementioned adsorbent material comprises a primary and / or secondary amine moiety immobilized on a solid support, the amine moiety at the α-carbon position being substituted with one hydrogen and one non-hydrogen substituent (R). Importantly, the treatment of chloromethylated poly(styrene-cordiginylbenzene) starting materials with hexamethylenetetramine (HMTA) disclosed in the experimental section of the relevant document results only in amination and the formation of primary amines. Secondary amines are not formed.

[0014] Patent Document 9 discloses a method for separating gaseous carbon dioxide from a gas mixture by circulating adsorption / desorption using a unit equipped with an adsorbent structure having the aforementioned sorbent material, the method comprising the following sequential and repeated steps in this order: (a) in the adsorption step, the gas mixture is brought into contact with the sorbent material using the velocity of the adsorbed gas flow to adsorb the aforementioned gaseous carbon dioxide under ambient atmospheric pressure and temperature conditions; (b0) the sorbent having the adsorbed carbon dioxide is isolated from the aforementioned flow-through of the gas mixture within the aforementioned unit; (b1 (b) a step of injecting a saturated steam flow essentially under ambient atmospheric pressure conditions, thereby inducing a rise in the temperature of the aforementioned sorbent to a temperature of 60-110°C; (b) a step of extracting at least desorbed gaseous carbon dioxide while still injecting and / or circulating saturated steam into the aforementioned unit under ambient atmospheric pressure conditions; (c) a step of bringing the sorbent material to ambient atmospheric temperature conditions, wherein the velocity of the steam flow passing through the unit in step (b1) and / or the average velocity in steps (b1)-(b3) is in the range of 0.5-10 times the velocity of the adsorbed gas flow in step (a).

[0015] Patent Document 10 discloses a method for separating carbon dioxide from a mixture with a non-acidic gas such as air by adsorption onto a weakly basic ion exchange resin and subsequent desorption with vapor, wherein the desorption is carried out under conditions such that the vapor condenses at the inlet end of the resin bed, and then the leading edge of the condensed vapor gradually passes through the bed to exhaust the carbon dioxide. Adsorption is appropriately carried out at a relative humidity of 40-90F and 75-90%. Preferred ion exchangers are polystyrene-divinylbenzene copolymers containing polyamino functional groups, each containing at least one secondary amino nitrogen atom. The figure shows an automatically controlled single-bed adsorption-regeneration system.

[0016] Patent Document 11 discloses an anion exchange resin with a high exchange capacity having a dual functional group and a method for synthesizing the same. This invention relates to the synthesis and application fields of environmental functional materials. This resin is based on a chloromethylated polystyrene-divinylbenzene polymer as a matrix, and by primary amination and quaternization, an anion exchange resin having a dual functional group with both a weakly basic anion group and a strongly basic anion group can be obtained. This anion exchange resin not only has a high adsorption capacity for nitrate ions in water, but also effectively suppresses natural organic acids such as phytic acid in water, and therefore, both nitrate ions and phytic acid organic substances can be simultaneously removed from water. Therefore, this resin has broad application possibilities in the fields of drinking water treatment, groundwater purification, and advanced municipal sewage treatment.

[0017] Patent Document 12 relates to an anion exchange composition containing an anion exchange functional group containing at least a first and a second nitrogen group, wherein the first nitrogen group is a positively charged quaternary amine, and the second nitrogen group is selected from the group consisting of primary, secondary, tertiary or quaternary amines. A method for preparing and using this composition is also provided.

Prior Art Documents

Patent Documents

[0018]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

[0019] [Non-licensed Document 1] Alesi et al. in Industrial & Engineering Chemistry Research 2012, 51, 6907-6915 [Non-licensed Document 2] Veneman et al. in Energy Procedia 2014, 63, 2336 [Non-licensed Document 3] Yu et al. in Industrial & Engineering Chemistry Research 2017, 56, 3259-3269 [Non-licensed Document 4] Kim et al., Bull Chem. Soc. Jpn. 2015, 88, 1317-1322 [Non-licensed Document 5] Heydari-Gorji et al. (Polyethylenimine-Impregnated Mesoporous Silica: Effect of Amine Loading and Surface Alkyl Chains on CO2 Adsorption, Langmuir 2011, 27, 12411-12416) [Non-licensed Document 6] Zhang et al. (Capturing CO2 from ambient air using a polyethyleneimine-silica adsorbent in fluidized beds, Chemical Engineering Science 116 (2014) 305-316) [Overview of the project]

[0020] The amine reacts with CO2 to form a carbamate moiety, which can then be regenerated back into the original amine in the next step, for example, by raising the temperature of the sorbent bed to about 100°C, thereby releasing the CO2. An economically viable process for carbon capture means the ability to carry out hundreds or thousands of cycles of cyclic adsorption / desorption of CO2 on the same sorbent material, and the sorbent should not undergo any chemical transformations that hinder its reactivity with CO2, or only very minor chemical transformations. The copolymerization of styrene and divinylbenzene is shown in Scheme 1.

[0021] [ka]

[0022] To convert such systems (e.g., in particulate form) into materials suitable for carbon dioxide recovery, they can be chloromethylated in the first step to form a chloromethylated styrene-divinylbenzene resin, and then aminated to form a primary benzylamine group, which then provides a primary amine for carbon dioxide recovery. Amination can be carried out, for example, by reacting the chloromethylated styrene-divinylbenzene resin with hexamethylenetetramine, followed by hydrolysis, typically under acidic conditions.

[0023] While these primary amine systems function well for carbon dioxide recovery purposes, including direct air recovery, even higher recovery capacities are needed for more efficient carbon dioxide removal processes.

[0024] According to the present invention, this objective is achieved by a novel method for producing such a material, and a method for separating gaseous carbon dioxide from a gas mixture using a novel sorbent material produced, for example, according to claim 1.

[0025] In the aforementioned Patent Document 8, the experimental section discloses the reaction of a chloromethylated poly(styrene-codicinylbenzene) starting material with hexamethylenetetramine (HMTA), which results in a simple amination, and it should be noted that the resulting product is a primary amine poly(styrene-codicinylbenzene) system according to the following scheme.

[0026] [ka]

[0027] Furthermore, Patent Document 10, mentioned above, discloses the reaction of chloromethylated poly(styrene-co-divinylbenzene) starting materials with diamine systems, but only with polyamine systems such as diethylenetriamine or triethylenetetramine. The focus there is on using polyfunctional amine systems, and the polyamine chains bonded to the divinylbenzene skeleton structure result in mainly secondary amine functional groups being obtained in the resulting system.

[0028] Surprisingly, as will be further detailed and demonstrated below, the claimed system exhibits superior properties compared to polyamine systems known in the prior art, particularly when the diamine system is selected to have a chain length of 3 to 4 carbon atoms.

[0029] According to a first aspect of the present invention, the present invention relates to a method for preparing an sorbent material for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air, flue gas, and biogas, wherein the gas mixture includes gaseous carbon dioxide as well as other gases different from gaseous carbon dioxide, and the separation is carried out by cyclic adsorption / desorption using an sorbent material that can reversibly bind carbon dioxide and adsorb the aforementioned gaseous carbon dioxide within a unit. Accordingly, the aforementioned use for separating gaseous carbon dioxide from a gas mixture is an use involving cyclic adsorption / desorption using this sorbent material that can reversibly bind carbon dioxide and adsorb the aforementioned gaseous carbon dioxide within a unit. Therefore, the sorbent material is a material that can reversibly bind carbon dioxide and adsorb the aforementioned gaseous carbon dioxide within a unit in such a process.

[0030] According to a first aspect of the present invention, a method for preparing such an sorbent material includes a method for preparing such an sorbent material from scratch, i.e., using a starting solid carrier precursor material that has not been previously used in a corresponding carbon dioxide recovery process. However, it also includes a method in which the solid carrier precursor starting material has already been used in such a carbon dioxide recovery process, and the method is used for the regeneration of the corresponding material, i.e., to regenerate the initial recovery capacity to at least some extent. This regeneration can be carried out using a used sorbent material as a solid carrier precursor that has not been previously treated by the claimed method, but can also be carried out using a material such as a solid carrier precursor that has been previously treated by the claimed method and then used in a carbon dioxide recovery process until it reaches a corresponding degradation level, and then the method is applied again to regenerate (in this case, refunctionalize) and reconstruct the recovery capacity of the corresponding solid carrier precursor.

[0031] The corresponding carbon dioxide recovery process that the sorbent material has undergone before being subjected to such a regeneration process is typically a carbon dioxide recovery process that alternates between recovery and release steps, with fluctuations in heat and / or temperature and / or humidity. Therefore, the starting material for the proposed regeneration method is an sorbent material that has been previously used as an adsorbent for carbon dioxide separation from gas mixtures, but has been oxidized by its use in this context and has typically lost at least 30% of its initial carbon dioxide recovery capacity. Accordingly, the regeneration of such an sorbent material is preferably performed when the carbon dioxide recovery capacity has decreased by more than 30%, preferably more than 20%, more preferably more than 15%, compared to the carbon dioxide recovery capacity of unused sorbent material, or after the sequence of adsorption / desorption steps has been repeated at least 500 times, preferably at least 1,000 times, more preferably at least 10,000 times, but preferably before the sequence of steps has been repeated 50,000 times, preferably before the sequence of steps has been repeated 25,000 times.

[0032] The sorbent material (obtained as a result of this method) comprises a primary amine moiety immobilized on a solid support, and at least one of a secondary amine moiety and a tertiary amine moiety. Preferably, it is an sorbent material having a secondary amine moiety in addition to a primary amine functional group immobilized on a solid support.

[0033] According to this method, in the first step, a solid support precursor having at least one of a primary amine functional group and a secondary amine functional group is provided (this may be an unused material, as noted above, or a material that has already been used in such a carbon dioxide recovery process and which this method uses for the regeneration of the corresponding material), preferably having a primary amine functional group. Next, in the second step, this solid support precursor is reacted with at least one reactant selected from the following group.

[0034] [ka]

[0035] [In the formula, PG is a protecting group, However, PG may also have a cyclic group in which one of the ring branches replaces a hydrogen atom bonded to the protected secondary amine portion of the reactant. X is a leaving group, i is in the range of 1 to 6 in the left structure and 0 to 5, particularly 1 to 3, in the right structure, and includes not only the -CH2- type portion but also the -CH(CH3)- type portion (preferably, there is only one -CH(CH3)- type portion).

[0036] Preferably, a post-functionalization degree of 10-80%, preferably 10-30%, is targeted. Next, in the third step, the material resulting from the second step is converted into the aforementioned sorbent material by removing the aforementioned protecting groups.

[0037] Of particular note is that the solid support precursor does not contain any alkyl halides, especially alkyl chlorides, as pendant groups that can be used in reaction with the reactants, or in particular, does not contain any such methyl chloride groups.

[0038] A typical approach to producing the corresponding sorbent material and generating primary amine groups for the sorbent material / solid support precursor is via chloromethylation followed by amination (see the scheme above). When this is modified by the addition of an alkyldiamine moiety, the corresponding pathway is used, but the step following chloromethylation is replaced by amination with the alkyldiamine moiety, as shown below (and detailed in Patent Document 10).

[0039] [ka]

[0040] Therefore, this conventional approach results in crosslinking, leading to a corresponding reduction in the total amount of primary amine moieties, which are known to be most active in CO2 recovery from air. This ultimately leads to reduced carbon recovery capacity and, consequently, to a less effective sorbent.

[0041] The proposed approach, although involving a longer synthetic pathway, offers significant advantages, including avoiding crosslinking and providing at least one of the following: higher carbon dioxide capture capacity, faster reaction rate, and greater stability.

[0042] This approach can be summarized as follows: the upper branch represents a pathway using covalent protecting groups, and the lower branch represents a pathway using salt-type protecting groups. The starting materials shown on the left have corresponding surface-accessible structures of the primary amine type, and the corresponding solid support precursors may be structured / porous polymers, silica, or even Class II or Class III MOFs.

[0043] [ka]

[0044] According to a preferred embodiment of the proposed method, the protecting group is selected from the group consisting of HCl, HBr, hydrogen halides including HI (especially in the case of precursor materials having primary amine functional groups), phthalimide (especially in the case of precursor materials having primary amine functional groups), tert-butyloxycarbonyl, p-toluenesulfone, benzylidene, acetate / acetamide, or trifluoroacetate / trifluoroacetamide.

[0045] Therefore, this type of system

[0046] [ka]

[0047] (For example, when i=2 and only -CH2- exists) this includes the following types of systems:

[0048] [ka]

[0049] [where, X - [ is an anion, preferably a tosylate, mesylate, or particularly halogen, especially selected from the group of Cl, I, and Br]

[0050] Possible examples are as follows:

[0051] [ka]

[0052] The following types of systems are also possible (Note: Cl - This is X as defined above. - (It can generally be replaced by, and Cl as a substituent can be replaced with X, i.e., a leaving group as defined herein.)

[0053] [ka]

[0054] This type of system

[0055] [ka]

[0056] [In the formula, PG is hydrogen halide.] This can be provided for the reaction by starting with a system having a primary amine and X=OH, and reacting it with a reagent such as thionyl chloride.

[0057] Therefore, for example, such a path can be observed as follows.

[0058] [ka]

[0059] The general structure of the reagent may be as follows.

[0060] [ka]

[0061] [In the formula, X is a halogen, particularly Cl, Br, or I, and i is 1 to 6, particularly 1 to 3, where the -CH2- type portion is also included in addition to the -CH(CH3)- type portion (preferably, only one -CH(CH3)- type portion is present)]

[0062] Examples are as follows:

[0063] [ka]

[0064] The advantage of using this approach is that reagents can be prepared from readily available alkanolamine starting materials and can be used directly for processing solid support precursors without requiring further purification. For example, the reaction product can be combined with the solid support precursor by providing ethanolamine in a solvent, reacting it with thionyl chloride, and then adding the solid support precursor to the corresponding solution or suspension.

[0065] According to a preferred embodiment of the proposed method, the conversion to the aforementioned sorbent material is carried out by removing the aforementioned protecting group using an organic base, an inorganic base, or a combination thereof. Preferably, the organic base is selected from the group consisting of pyridine, alkylamines, such as triethylamine, imidazole, and tetramethylammonium hydroxide, and the inorganic base is preferably selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, and combinations thereof.

[0066] According to another preferred embodiment of the proposed method, the step of reacting with the reactants and / or removing the aforementioned protecting group is carried out in an organic solvent or an inorganic solvent or a combination thereof, preferably the solvent is selected from the group consisting of water, methanol, ethanol, dimethoxymethane, tetrahydrofuran, dimethylformamide, or a combination thereof, and preferably the solvent is water.

[0067] According to a further preferred embodiment of the proposed method, the reactant is added to the solid support precursor in an equivalent ratio of 0.1 to 10, preferably 0.1 to 1.0, relative to the primary / secondary amine of the solid support precursor.

[0068] According to yet another preferred embodiment of the proposed method, the solid support precursor is polystyrene-based, preferably polystyrene-based benzylamine, polystyrene-based allylamine, and preferably the solid support precursor is an amine-functionalized styrene-divinylbenzene support, preferably functionalized with primary benzylamine or primary α-methylbenzylamine, or a styrene-allylamine support. And / or, the solid support precursor is a solid styrene-divinylbenzene support functionalized with primary benzylamine or primary α-methylbenzylamine groups as a result of the reaction of halogenated methylated styrene-divinylbenzene, preferably chloromethylated styrene-divinylbenzene, with hexamethylenetetramine, or through amidomethylation of styrene-divinylbenzene and subsequent hydrolysis.

[0069] With regard to styrene-allylamine supports, the disclosures of European Patent Application No. 23212181.4 relating to their manufacture, structural characterization, and characterization are expressly incorporated herein.

[0070] According to another preferred embodiment of the proposed method, the reactants have i = 1 to 4, preferably i = 1 to 3.

[0071] Preferably, the solid carrier precursor material, preferably in the form of a primary benzylamine-based carrier material or a styrene-allylamine carrier, is in the form of at least one of a monolith, a layer or sheet, a hollow or solid fiber, preferably a woven or nonwoven structure, a hollow or solid particle, or an extruded product, and preferably the solid carrier precursor material takes the form of essentially spherical beads.

[0072] Preferably, the solid carrier material based on a primary benzylamine styrene-divinylbenzene carrier material or a styrene-allylamine carrier is in the form of at least one of a monolith, a layer or sheet, a hollow or solid fiber, preferably a woven or nonwoven structure, a hollow or solid particle, or an extruded product, and preferably the solid carrier material takes the form of essentially spherical beads.

[0073] Preferably, the solid carrier material, in the form of a styrene-divinylbenzene-based carrier material or a styrene-allylamine carrier, may be in the form of solid particles embedded in a porous or non-porous matrix.

[0074] The adsorbent material may take the form of essentially spherical beads having a particle size (D50) in the range of 0.002-4 mm, 0.005-2 mm, 0.002-1.5 mm, 0.005-1.6 mm, or 0.01-1.5 mm, preferably in the range of 0.30-1.25 mm.

[0075] According to a preferred embodiment of the proposed method, reactant X is selected from the group consisting of halogens, tosylates, mesylates, esters, imides, carbodiimides, and pyrazoles.

[0076] According to another aspect of the present invention, the present invention relates to an adsorbent material capable of reversibly binding carbon dioxide for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air, flue gas, and biogas, preferably for direct air recovery, particularly using temperature, vacuum, or temperature / vacuum swing processes, wherein the aforementioned adsorbent material can be obtained or is obtained using the method defined above. The adsorbent material comprises a primary amine moiety and at least one of a secondary amine moiety and a tertiary amine moiety immobilized on a solid support, and preferably the adsorbent material is an adsorbent material having a secondary amine moiety in addition to a primary amine functional group immobilized on a solid support.

[0077] According to yet another aspect of the present invention, the present invention relates to the use of such sorbent material for separating gaseous carbon dioxide from a gas mixture, or, in other words, a method for separating carbon dioxide from a gas mixture using such sorbent material, preferably for separating CO2 from at least one of ambient air, flue gas and biogas, preferably for direct air recovery, particularly using a temperature, vacuum or temperature / vacuum swing process, wherein the sorbent material comprises a primary amine moiety and a secondary amine and / or ether moiety immobilized on a solid carrier, and the use or method relates to such use.

[0078] Preferably, such a method for separating gaseous carbon dioxide comprises at least the following sequential and repeated steps (a) to (e): (a) In the adsorption step, under ambient atmospheric pressure and ambient air temperature conditions, the aforementioned gas mixture is brought into contact with an sorbent material to adsorb at least the aforementioned gaseous carbon dioxide (part or essentially all of it) onto the sorbent material by flow-through through the aforementioned unit (and thus through and / or over the sorbent material that adsorbs at least a portion of the aforementioned gaseous carbon dioxide) (even if the ambient air is pushed / drawn through the apparatus using a ventilation device, etc., and the pressure of the air pushed / drawn through the reactor by the ventilation device is slightly higher or lower than the ambient atmospheric pressure, this is still considered ambient atmospheric pressure conditions in accordance with this application, and the pressure is within the range detailed below in the definition of “ambient atmospheric pressure”), (b) The step of isolating the aforementioned sorbent material having adsorbed carbon dioxide within the aforementioned unit from the aforementioned flow-through, preferably while essentially maintaining the temperature within the sorbent, (c) A step of initiating the desorption of CO2 by inducing a rise in the temperature of the sorbent material to a temperature of preferably 60-110°C. This is, for example, by injecting a flow of saturated or superheated steam, preferably by flow-through through the unit and over / through the sorbent, thereby inducing a rise in the temperature of the sorbent material to a temperature of 60-110°C to initiate the desorption of CO2. (d) Extracting at least desorbed gaseous carbon dioxide from the unit and separating the gaseous carbon dioxide within the unit or downstream of the unit, preferably by condensation. (e) Bringing the sorbent material to ambient air temperature and ambient atmospheric pressure conditions (even if the sorbent material is not exactly cooled to the ambient air temperature conditions in this step, this is still considered to be following this step, and preferably the ambient air temperature established in step (e) is within the range of ambient air temperature + 25°C, preferably + 10°C or + 5°C). A method that includes or is used.

[0079] In the context of this disclosure, the terms “ambient atmospheric pressure” and “ambient air temperature” refer to the pressure and temperature conditions to which a plant operating outdoors is exposed, namely, typically ambient atmospheric pressure refers to a pressure in the range of 0.08 to 0.11 MPa (0.8 to 1.1 bar) (absolute pressure), and typically ambient air temperature refers to a temperature in the range of -40 to 60°C, more typically -30 to 45°C. The gas mixture used as input to the process is preferably ambient air, i.e., air at ambient atmospheric pressure and ambient air temperature, which usually means a CO2 concentration in the range of 0.03 to 0.06 volume%. However, air with lower or higher CO2 concentrations, e.g., 0.1 to 0.5 volume% can also be used as input to the process, and therefore, generally speaking, the input CO2 concentration of the input gas mixture is preferably in the range of 0.01 to 0.5 volume%.

[0080] According to a further aspect of the present invention, the present invention relates to a unit for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air, flue gas, and biogas, preferably a direct air recovery unit, comprising at least one reactor unit containing an sorbent material suitable and adapted for the flow-through of the aforementioned gas mixture, The aforementioned reactor unit has an inlet for the aforementioned gas mixture, preferably for ambient air, and an outlet for the aforementioned gas mixture, preferably for the ambient air being adsorbed. The aforementioned reactor unit is capable of heating to a temperature of at least 60°C for the desorption of the aforementioned gaseous carbon dioxide, and the aforementioned reactor unit is capable of opening to allow the gas mixture, preferably the ambient air, to flow through and to bring the gas mixture into contact with the sorbent material for the adsorption step, and preferably the aforementioned reactor unit is capable of further evacuation to a vacuum pressure of 0.04 MPa (400 mbar) (absolute pressure) or less. The aforementioned adsorbent material preferably takes the form of at least a part of an adsorbent structure including an array of individual adsorbent elements, and each adsorbent element preferably has at least one carrier layer and at least one adsorbent material layer containing or consisting of at least one adsorbent material, Preferably, the adsorbent elements in the aforementioned array are arranged essentially parallel to each other and spaced apart from each other to form parallel fluid passages for the flow-through of the aforementioned gas mixture, preferably ambient air and / or vapor. The unit comprises at least one device for separating carbon dioxide from water, preferably a condenser. Preferably, the aforementioned apparatus for separating carbon dioxide from water, preferably the gas outlet side of the aforementioned condenser, includes at least one, preferably both, of a carbon dioxide concentration sensor and a gas flow sensor for controlling the desorption process. Regarding the unit.

[0081] Further embodiments of the present invention are described in the dependent claims.

[0082] Preferred embodiments of the present invention will be described below with reference to the drawings, but these are for the purpose of illustrating current preferred embodiments of the present invention and are not intended to limit the present invention. [Brief explanation of the drawing]

[0083] [Figure 1] This is a schematic diagram of a direct air recovery unit. [Figure 2] This figure shows the increase in carbon dioxide recovery capacity by post-modification of two different starting benzylamine beads. [Figure 3] This figure shows the increase in carbon dioxide recovery capacity through chloromethylation and amination in different systems. [Figure 4] This figure shows a comparison of the increased carbon dioxide recovery capacity achieved by chloromethylation and amination with post-functionalization. [Figure 5]This figure shows the improvement in the reaction rate of materials obtained by post-modification of two different solid supports. [Figure 6] This figure shows the increase in carbon dioxide recovery capacity of benzylamine beads by post-modification using 2-methylchloropropylamine HCl and 1-methylchloropropylamine HCl. [Figure 7] This figure shows the increase in carbon dioxide capture capacity due to post-modification of allylamine derivatives. [Figure 8] This figure shows the increased carbon dioxide capture capacity of structured sorbents (beads or amine sorbents embedded within the structure) through post-modification. [Figure 9] This figure shows the carbon dioxide recovery capacity of deteriorated beads through post-modification for regeneration or refunctionalization. [Modes for carrying out the invention]

[0084] Synthesis procedure for primary amine-functionalized styrene-divinylbenzene resins: In a 1 L reactor, dissolve 1% (by mass) gelatin and 2% (by mass) sodium chloride in 300 mL of water at 45°C for 1 hour and 30 minutes. In a separate flask, dissolve 1 g of benzoyl peroxide in a mixture of 54 g of styrene, 10 g of divinylbenzene (80% content), 68 g of heptane, and 22 g of toluene. Then add the resulting mixture to the reactor. The reaction mixture is then stirred and heated to 70°C, maintained at this temperature for 2 hours, then raised to 80°C and held for 16 hours. The temperature is then raised to 35-100°C for 3 hours to remove the pologen by distillation. The reaction mixture is cooled to room temperature, and the beads are filtered off using a funnel glass filter and vacuum suction.

[0085] The beads are dried in rotavapor. The polystyrene-divinylbenzene beads are functionalized using a chloromethylation reaction. 5 g of the beads obtained in this way are added to a three-necked flask containing 30 mL of chloromethyl methyl ether. 3.5 g of zinc chloride is added to the mixture over 2 hours, and the mixture is heated to 60°C for a further 4 hours. The mixture is then cooled to room temperature, and the chloromethyl methyl ether is quenched by adding a 25% aqueous HCl solution. The chloromethylated beads are washed with water until neutral, filtered, and dried.

[0086] To obtain benzylamine, chloromethyl-functionalized polystyrene-divinylbenzene beads are aminated using the benzylamine amination reaction. Chloromethylated beads are added to a three-necked flask with 27 g of methylal, and the mixture is stirred at 25°C (room temperature) for 1 hour. 9 g of hexamethylenetetramine and 12 g of water are added to this mixture, and the mixture is held under gentle reflux for 6 hours. The beads are filtered off and washed with water. To obtain the primary amine, a hydrolysis step followed by a base treatment is required. The beads are placed in a three-necked flask containing 140 mL of a hydrochloric acid (30%)-ethanol (95%) solution (volume ratio 1:3), and the reaction mixture is heated to 80°C and maintained at this temperature for 20 hours. The beads are then filtered off and washed with water. At this stage, the amine is protonated, and to liberate the base, the beads are treated with 50 mL of 2 M NaOH solution and stirred at 50°C for 1 hour. The aminated beads are filtered off and washed with desalted water to a neutral pH.

[0087] Synthesis procedure and comparative example of diamine-functionalized styrene-divinylbenzene resin: To obtain a diamine (which involves crosslinking as a side reaction, but is not part of the present invention), chloromethyl-functionalized polystyrene-divinylbenzene beads are aminated using a direct amination reaction. Add 6 g of chloromethylated beads to a three-necked flask along with 23 g of methylal, and stir the mixture at 40°C for 1 hour. Add one of the following amounts of amine to this mixture, depending on the final functional group of the amino sorbent: 12g of 1,2-ethylenediamine, 15g of 1,3-propylenediamine, 18g of 1,4-butanediamine, 21g of 1,5-pentanediamine, 23g of 1,6-hexanediamine.

[0088] A mixture containing chloromethylated beads, methylal, and one of the above amines is kept at 50°C for 12 hours with stirring. The beads are filtered off and washed with methanol and water. The aminated beads are then dried in a vacuum oven at 60°C for 12 hours.

[0089] Procedure for the synthesis of diamine-functionalized styrene-divinylbenzene resin, example according to the present invention: Generally, a framework can be defined as follows: Examples of amines on sorbent carrier materials: polystyrene-based benzylamines; aliphatic amines (e.g., polyallylamines), and other functional groups that react well with the reagents listed above. Examples of solvents that can be used in the synthesis procedure of diamine functionalized systems: H2O, methanol, ethanol, dimethoxymethane, dimethylformamide, preferably H2O. Examples of bases: Organic bases such as alkylamines, e.g., triethylamine, pyridine, imidazole, tetramethylammonium hydroxide; inorganic bases, e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, and combinations thereof. Equivalent amount of amine reagent: For example, 0.1 to 1.0 compared to benzylaminestyrene-divinylbenzene.

[0090] Examples using phthalimide-protected amine reagents: Add 6 g of benzylamine beads to a three-necked flask along with 38 g of dimethylformamide (DMF), and stir the mixture at 25°C (room temperature) for 1 hour. Add the following to this mixture depending on the final functional group of the amino sorbent: 10g of N-(3-bromopropyl)-phthalimide, 11g of N-(3-bromobutyl)-phthalimide, 12g of N-(3-brompentyl)-phthalimide.

[0091] The mixture containing benzylamine beads, DMF, and the above-mentioned phthalimide-protected amine is kept at 60°C under stirring for 18 hours. The mixture is then cooled to room temperature, the beads are filtered off, and the mixture is washed with methanol and water.

[0092] Next, add the beads to the autoclave and add 20g of 10M NaOH aqueous solution. Heat the autoclave to 180°C for 10 hours. Wash the beads with water and methanol, and dry them in a vacuum oven at 60°C for 12 hours.

[0093] Examples using salt-protecting amine reagents (e.g., bromopropylammonium bromide or chloropropylammonium chloride): Add 5 g of benzylamine beads to a three-necked flask along with 30 g of dimethylformamide (DMF), and stir the mixture at 25°C (room temperature) for 1 hour. To this mixture, add the following depending on the final functional group of the amino sorbent: 8g of 3-bromopropylamine hydrobromide, 5g of 3-chloropropylamine hydrochloride.

[0094] A mixture containing benzylamine beads, DMF, and the above-mentioned amine is kept at 60°C for 18 hours under stirring. The mixture is then cooled to room temperature, the beads are filtered off, and washed with water. The beads are then stirred in a 2M NaOH aqueous solution for 1 hour, washed with water and methanol until neutral, and dried in a vacuum oven at 60°C for 12 hours.

[0095] The calculated conversion rate from the nitrogen content measured by elemental analysis reaches 13-15% (the N content (by weight) is 9.8 when sorbent B is used as the starting material, and 12.4 when sorbent A is used as the starting material).

[0096] An example of refunctionalization of degraded benzylamine beads with chloropropylamine hydrochloride: Reaction procedure Add 28g of beads and 195g of water (183 + 11 from the beads) to the reactor and stir the beads for 20 minutes. Next, 50g of 30% NaOH is added to the reactor. Dissolve 107.5g of chloropropylammonium chloride in a beaker containing 250g of water for 20 minutes, then add the mixture to the reactor. Rinse the beaker with 50g of water. React at 65°C for 7 hours while stirring. Stop heating, draw up the reaction mixture (420g, approximately 400mL) using a siphon, add 400mL of deionized water, stir for 15 minutes, draw up the water using a siphon, and repeat the washing process once more (400mL, stir for 15 minutes). Remove the water, then add 400 ml of 2 M NaOH, stir at room temperature for 1 hour, siphon out the NaOH, and wash the beads with DI water (3.5 L) to a neutral pH.

[0097] The results are shown in Figure 9, illustrating how spent materials can be recovered in terms of their recyclability.

[0098] Examples of salt-protected amine reagents for subsequent reactions with benzylamine sorbents (2-chloropropylamine hydrochloride and 1-chloropropylamine hydrochloride): 2-Chloropropan-1-amine hydrochloride 32 g of amino-2-propanol and 150 mL of dioxane are placed in a 1 L round-bottom flask. 150 mL of 4N HCl solution is added to the dioxane, and the mixture is stirred at room temperature for 10 minutes. 34.5 mL of thionyl chloride is slowly added over 2 minutes. The reaction mixture is stirred at 80°C for 18 hours. The mixture is cooled to room temperature and diluted with 200 mL of Et2O. The resulting precipitate is filtered off, washed with 200 mL of Et2O, and dried under vacuum to obtain 50 g of 2-chloropropane-1-amine hydrochloride.

[0099] 1-Chloropropane-2-amine hydrochloride 10 g of 2-amino-1-propanol and 75 mL of dioxane were placed in a 1 L round-bottom flask. 75 mL of 4N HCl solution was added to the dioxane, and the mixture was stirred at room temperature for 10 minutes. 17 mL of thionyl chloride was slowly added over 2 minutes. The reaction mixture was stirred at 80°C for 18 hours. The mixture was cooled to room temperature and diluted with 150 mL of Et2O. The resulting precipitate was filtered off and washed with 150 mL of Et2O to obtain 25 g of hygroscopic 1-chloropropane-2-amine hydrochloride, which was immediately used for the next step.

[0100] To obtain divinylbenzene beads: Adsorbent B was functionalized using the reagents 2-chloropropane-1-amine hydrochloride and 1-chloropropane-2-amine hydrochloride, respectively, to obtain a post-functionalized material. In the case of 2-chloropropan-1-amine hydrochloride, the reaction pathway is as follows:

[0101] [ka]

[0102] The calculated conversion rate from the nitrogen content measured by elemental analysis reaches 13-15% (N content (weight %): 10.7).

[0103] In the case of 1-chloropropane-2-amine hydrochloride, the reaction pathway is as follows:

[0104] [ka]

[0105] This results in the recovery capability shown in Figure 6.

[0106] The calculated conversion rate from the nitrogen content measured by elemental analysis reaches 13-15% (N content (weight %): 10.4).

[0107] Examples of non-benzylamine sorbents using 3-chloropropylamine hydrochloride, such as the functionalization of polyallylamine-divinylbenzene: Synthesis procedure for acrylonitrile-divinylbenzene resin 300 g of deionized water, 0.2 g of hydroxyethylcellulose, and 15 g of sodium chloride were added to a 1 L reactor, and the mixture was stirred at 300 rpm at 50°C for 1 hour to completely dissolve the contents (Solution A). Separately, 70 g of acrylonitrile, 30 g of divinylbenzene, 100 g of toluene, and 1 g of azobisisobutyronitrile were placed in a 200 mL beaker, and the mixture was stirred at 300 rpm at room temperature for 1 hour to completely dissolve them (Solution B). Solution B was added to Solution A all at once while stirring, and the temperature of the reaction solution was set to 65°C. After the reaction solution reached 65°C, the reaction was continued for 18 hours.

[0108] Next, the reaction solution was cooled to room temperature and filtered. Then, the solid was transferred to a 1 L beaker, 1 L of deionized water was added, and the mixture was stirred with a magnetic stirrer for 30 minutes and filtered. This was repeated once more. Next, the solid was transferred to a 1 L beaker, 1 L of methanol was added, and the mixture was stirred with a magnetic stirrer for 30 minutes and filtered. The desired polymer particles were then dried at 75°C and under reduced pressure of 200 Torre for 1 hour. The average particle size was 330 micrometers, the pore size determined by mercury intrusion was 75 nanometers, and the specific surface area determined by BET was 62 m². 2 It was / g.

[0109] The beads are dried in rotavapor. Then, the acrylonitrile-divinylbenzene beads are reacted with a reducing agent to obtain allylamine-divinylbenzene beads.

[0110] To obtain allylamine-divinylbenzene beads: Acrylonitrile-divinylbenzene beads (7g) were added to a three-necked flask, flushed with nitrogen, and the flask was cooled in an ice bath. Borane-THF solution (1M, 80mL) was added dropwise while stirring. After the addition was complete, the reaction temperature was raised to 65°C (reflux) and the mixture was stirred for 24 hours.

[0111] Next, the mixture is cooled to 0°C, 100 mL of 2 M HCl (aqueous solution) is added to methanol, and the mixture is stirred at 40°C for 3 hours. After that, the beads are filtered off and washed with water. At this stage, the amine is protonated, so to liberate the base, the beads are treated with 50 mL of 2 M NaOH solution and stirred at 40°C for 1 hour. The aminated beads are filtered off and washed with desalted water to a neutral pH.

[0112] Post-functionalization of polyallylamine-divinylbenzene beads: The reaction scheme here is as follows:

[0113] [ka]

[0114] Add 14g of sodium hydroxide aqueous solution (30% by weight NaOH aqueous solution) to a three-necked flask. Then add 5.5g of polyallylamine-divinylbenzene beads, followed by 10g of 3-chloropropylamine hydrochloride (1.1 equivalents) pre-dissolved in 10mL of water. Once completely dissolved, adjust the internal temperature of the flask to 65°C for 6 hours.

[0115] Next, add 400 mL of water twice, filtering each time. Add 400 mL of 2 M sodium hydroxide solution to the flask and stir the mixture at room temperature for 1 hour. Siphon up the reaction solution and repeat the washing procedure with deionized water until the washing water pH is less than 8.

[0116] The results are shown in Figure 7, illustrating how the allylamine sorbent material can be enhanced in terms of recovery capacity.

[0117] Procedure for embedding benzylamine sorbent in a structure / sheet: The sheet can be manufactured from a mixture of 50% by weight (wet, approximately 85% solids) of ion exchange resin (IER) powder with an average particle size of 75 microns (D50, volume basis) and 50% by weight of ultra-high molecular weight polyethylene (UHMWPE, molecular weight 4.2 million g / mol) with an average particle size of 30 microns (D50). These two powders are mixed for 15 minutes using a 3D rotary mixer. Approximately 8 g of the powder mixture is filled into an aluminum mold with a cross-section of 10 × 20 mm. The mold is closed and placed in an oven preheated to 220°C. No pressure is applied. The mold is placed on a small metal support to facilitate double-sided heating and kept at that temperature in the oven for 40 minutes. The mold is then removed from the oven and allowed to cool in ambient air to room temperature before being opened. Upon opening, a sheet matching the internal dimensions of the mold is obtained. The density of this sheet is typically 450–500 kg / m³.

[0118] Examples of functionalization of benzylamine sorbents embedded in structures / sheets: Add 165 ml of water to the reactor, then add 35.8 g of chloropropylammonium chloride and stir for 20 minutes until dissolved.

[0119] Next, 50g of 30% NaOH is added to the reactor. Then, the sheets are added to the reactor and the mixture is heated to 65°C while stirring. The reaction is carried out at this temperature for 7 hours. The sheets are removed, washed with 1.5L of deionized water, and stirred for 30 minutes.

[0120] Next, the sheets are suspended in 100 ml of 2 M NaOH for 1 hour, and then added to a 2 L beaker containing deionized water and washed until neutral. Air dry for 16 hours.

[0121] The results are shown in Figure 8, illustrating how structured sorbent materials can be enhanced in terms of recovery capacity and how they can be regenerated using this method.

[0122] Formation of haloalkylamine hydrohalides (e.g., 3-chloropropylamine hydrochloride) from alcoholamines: To a solution of thionyl chloride (17.36 g) in chloroform (60 mL), add 3-aminopropan-1-ol (8.98 g) dropwise while maintaining the temperature at 0-10°C.

[0123] Next, warm the mixture to room temperature, then slowly heat it to 45°C. Stir at 45°C for 3 hours.

[0124] The solution is cooled to room temperature, then the intermediate is incorporated into H2O (60 ml), the chloroform is drained, and then the aqueous solution is washed again with chloroform (60 ml).

[0125] Add 10g of beads and 6g of NaOH pellets to the extract from the previous step. Then, heat the reaction mixture to 65°C and allow it to react with stirring for 7 hours.

[0126] Stop heating, remove the reaction mixture (42g, approximately 40mL) using a siphon, add 40mL of deionized water, stir for 15 minutes, draw up the water using a siphon, and repeat the washing process once more (40mL, stir for 15 minutes).

[0127] Remove the water, then add 40 ml of 2 M NaOH solution. Stir at room temperature for 1 hour, then siphon out the NaOH.

[0128] Wash the beads with NaOH and then with DI water (2.5L) until the pH is neutral.

[0129] Carbon dioxide capture capacity characteristics: The beads according to the above example were tested in an experimental apparatus in which the beads were placed in a packed-bed reactor or an air-permeable layer. This apparatus is schematically shown in Figure 1. There is an ambient air inlet structure 1, and the actual reactor unit 8 comprises a container or wall 7 in which the layer of sorbent material 3 is positioned. For example, if steam is used for desorption, there is an inlet structure 4 for desorption and a reactor outlet 5 for extraction. Furthermore, there is a vacuum unit 6 for exhausting the reactor.

[0130] Determining the replacement capacity: To measure the exchange volume, add approximately 2 g of wet material to a beaker containing 50 mL of 1 M NaOH solution and stir at room temperature for 40 minutes. Then, filter the solution through a Buchner funnel with a filter mesh size of 40 μm, wash the beads with deionized water until neutral, and collect them. Transfer about half of the beads to a volumetric flask, record the weight, and add 100 mL of 0.1 M HCl solution to the flask. Close the flask and leave it in an oven at 70°C for 1 hour. The solid content of the remaining half is determined according to the following method.

[0131] Next, remove the flask from the oven and allow it to cool to room temperature. Titrate 25 mL of the supernatant with 0.1 M NaOH solution (using an SI Analytics Titrator TitroLine 5000 until the inflection point). The exchange volume is given by the following formula: exchange capacity [meq / g] ={(25mL-mL NaOH 使用済み ) x 0.4} / (moisture weight x solid content) It is calculated by [this method].

[0132] Solids content: The solid content is measured using a halogen moisture analyzer (Adam Equipment PMB Moisture Analyzer). The measurement temperature is 110°C, and the measurement automatically stops at a certain weight (0.002 g / 15 seconds).

[0133] Nitrogen content measurement: Elemental analysis of the materials was performed using a LECO CHN-900 combustion furnace. Before measurement, the samples were treated at 90°C for 2 hours under an N2 flow (2 L / min). Alternatively, the samples were treated in a vacuum oven at 60°C for 6 hours.

[0134] Specific surface area measurement method: Nitrogen adsorption measurements were performed at 77K using a Quantachrome ASiQ. The mass of the samples used ranged from 0.2 to 1.0 g. Since the samples contain a considerable amount of water, it is important to use a treatment that does not alter the intrinsic porosity and pore structure. Therefore, before degassing, the samples were treated using the elutropic row method, which involves removing the water and replacing it with organic solvents with lower boiling points, namely methanol, acetone, and n-heptane in that order. 2 g of the sample was placed in a frit-equipped chromatography column and flushed with 20 cm³ of each solvent in descending order of polarity. The sample was then spread on a Petri dish and placed in a vacuum oven at 40°C for 24 hours. Subsequently, the samples were degassed under vacuum at 70°C for 12 hours before measurement. The BET (Brunauer, Emmett und Teller) surface area analysis was performed using the ISO 9277 method.

[0135] Mercury porosimetry: Mercury porosimetry was performed to analyze pore size and volume, which are inaccessible by N2 adsorption measurements. The following parameters were used to perform the mercury porosimetry. ·Mercury surface tension: 0.48N / m ·Mercury contact angle: 150° • Maximum pressure: 400 MPa • Pressure boosting speed: 6-19 MPa / min Prior to Hg porosimetry, the sample was degassed under vacuum at 70°C for 12 hours.

[0136] Calculation of post-functionalization degree (conversion rate): The degree of post-functionalization is calculated, for example, as the relative number of propylamine monomers per benzylamine or allylamine monomer.

[0137] Formula: Degree of post-functionalization = {[%N] × (1 - x) × MW モノマーA + [%N] × x × MW モノマーB} / (MW N - [%N] × MW アミン官能基化 ) [In the formula, [%N] is the nitrogen content (weight percentage) determined by elemental analysis, x is the proportion of monomer B in the polymer (for example, DVB content 10%, x = 0.1), MW モノマーA is the molecular weight (g / mol) of non-functionalized monomer A (for example, styrene, MW スチレン = 104.15 g / mol), MW モノマーB is the molecular weight (g / mol) of the crosslinking monomer (for example, divinylbenzene (DVB), MW DVB = 130.19 g / mol), MW <00​​​​​​​​​​​​​​​​​​​​As can be seen in Figure 2, single alkylamine substitution using a post-modification approach results in an unexpectedly large increase of 25–50% in equilibrium carbon dioxide recovery capacity. In fact, the equilibrium carbon dioxide recovery capacity increases as a function of the number of carbon atoms in the alkyl chain, reaching a maximum value at 4 or 5 carbon atoms, and then decreasing again. Surprisingly, the maximum value is observed in propylenediamine and butylenediamine in most systems, with an increase of almost 50% compared to unsubstituted benzylamine.

[0141] Figure 3 shows the corresponding carbon dioxide capture capacity when the material is produced using the conventional approach of chloromethylation followed by amination, rather than the post-modification method according to the present invention. In this case, the relative increase is only in the range of 5-30%, and is therefore significantly lower than when the proposed post-modification approach is used.

[0142] While not bound by any theoretical explanation, this is likely due to the fact that the post-modification approach using protecting groups avoids crosslinking, and therefore the amine recovery portion becomes available in an optimal manner.

[0143] Figure 4 shows a direct comparison of the carbon dioxide recovery capacity of sorbent C, obtained by chloromethylation and amination, with that of sorbents A and B, obtained by post-functionalization. Clearly, sorbents A and B exhibit superior carbon dioxide recovery capacity compared to sorbent C. While this is not bound by any theoretical explanation, it is thought to be due to the high usability of primary amines.

[0144] Figure 5 shows the improved reaction rate of the post-modified system, with a volume increase of 45-50%. Furthermore, the corresponding material was found to be able to undergo more recovery cycles without degradation compared to the benzylamine system. Additionally, the exchange volume in water increased by only a maximum of 15%, which is in good agreement with the calculated conversion rate of post-functionalization. [Explanation of symbols]

[0145] 1. Ambient air, ambient air inlet structure 2. Outflow of ambient air behind the adsorption unit in adsorption flow-through mode. 3. Adsorbent materials 4. Steam, steam inlet structure for desorption 5. Reactor outlet for extraction 6. Vacuum Unit / Separator 7 Walls 8 Reactor Unit

Claims

1. A method for preparing an sorbent material (3) for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air (1), flue gas, and biogas, wherein the gas mixture includes further gases other than gaseous carbon dioxide in addition to the gaseous carbon dioxide, and the separation is carried out by circulating adsorption / desorption using an sorbent material (3) that can reversibly bind carbon dioxide and adsorb the gaseous carbon dioxide within a unit (8). The aforementioned adsorbent material (3) is Immobilized on a solid carrier Primary amine portion and At least one of the secondary amine moiety and the tertiary amine moiety Includes, A solid support precursor is provided having at least one of a primary amine functional group and a secondary amine functional group, and The solid carrier precursors belong to the following group: 【Chemistry 17】 [In the formula, PG is a protecting group, However, PG may also be a cyclic group in which one branch of the ring replaces a hydrogen atom bonded to the protected secondary amine portion of the reactant. X is a leaving group, i is in the range of 1 to 6 in structure (I) and in the range of 0 to 5 in structure (II), and in both cases, -CH ２ -, -CH(CH ３ ) - Includes a substituted or non-substituted portion selected from the group consisting of ) - It is reacted with at least one reactant selected from and The resulting material is converted to the sorbent material (3) by removing the protecting group. method.

2. The protecting group is selected from the group consisting of HCl, HBr, hydrogen halides containing HI, phthalimide, pyrazoles containing pyrazole hydrochloride, tert-butyloxycarbonyl, para-toluenesulfone, benzylidene, acetate / acetamide, or trifluoroacetate / trifluoroacetamide. Preferably, in the case of a system of type (I) in which the protecting group is selected as a hydrogen halide comprising HCl, HBr, and HI, the reactant is provided for the reaction by starting with the respective alkanolamine, reacting it with an organic halogenating reagent comprising thionyl chloride, and then contacting it with the solid support precursor. The method according to claim 1.

3. The method according to claim 1 or 2, wherein the conversion to the sorbent material (3) is carried out by removing the protecting group using an organic base or an inorganic base or a combination thereof, and preferably the organic base is selected from the group consisting of alkylamines including triethylamine, pyridine, imidazole, and tetramethylammonium hydroxide, and preferably the inorganic base is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, and combinations thereof.

4. The method according to any one of claims 1 to 3, wherein the step of the reaction with the reactant and / or the removal of the protecting group is carried out in an organic solvent or an inorganic solvent or a combination thereof, preferably the solvent is selected from the group consisting of water, methanol, tetrahydrofuran, ethanol, dimethoxymethane, dimethylformamide, or a combination thereof, and preferably the solvent is water.

5. The method according to any one of claims 1 to 4, wherein the reactant is added to the solid support precursor in an equivalent ratio of 0.1 to 10, preferably 0.1 to 1.0, relative to the primary / secondary amine content of the solid support precursor.

6. The solid support precursor is at least one of a structured polymer and / or a porous polymer, silica, a Class II or Class III MOF, and in particular the solid support precursor is polystyrene-based, preferably polystyrene-based benzylamine, and preferably the solid support precursor is an amine-functionalized styrene-divinylbenzene support, preferably one functionalized with primary benzylamine or primary α-methylbenzylamine, or a styrene-allylamine solid support precursor. and / or, the solid support precursor is preferably a solid styrene-divinylbenzene support or styrene-allylamine solid support precursor functionalized with primary benzylamine or primary α-methylbenzylamine groups as a result of, or alternatively, the reaction of halogenated methylated styrene-divinylbenzene, preferably chloromethylated styrene-divinylbenzene, with hexamethylenetetramine, or through amidomethylation of styrene-divinylbenzene and subsequent hydrolysis. and / or the method is a regeneration method, wherein the solid support precursor is a solid support that can reversibly bind carbon dioxide and adsorb the gaseous carbon dioxide within the unit, which has been used to separate gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air (1), flue gas, and biogas, wherein the gas mixture includes further gases other than gaseous carbon dioxide in addition to the gaseous carbon dioxide, and the separation is carried out by cyclic adsorption / desorption. Preferably, such regeneration is performed when the carbon dioxide capture capacity has decreased by more than 30%, preferably more than 20%, more preferably more than 15%, compared to the carbon dioxide capture capacity of unused sorbent material, or the regeneration of the sorbent material is performed after the adsorption / desorption sequence has been repeated at least 500 times, preferably at least 1,000 times, more preferably at least 10,000 times, but preferably before the sequence of steps has been repeated 50,000 times, preferably before the sequence of steps has been repeated 25,000 times. The method according to any one of claims 1 to 5.

7. The method according to any one of claims 1 to 6, wherein the reactant has i=1 to 5, preferably i=1 to 4 or i=1 to 3, in structure (I), and i=1 to 4, preferably i=1 to 3, in structure (II).

8. The method according to any one of claims 1 to 7, wherein the solid carrier material, preferably in the form of a styrene-divinylbenzene-based carrier material or a styrene-allylamine carrier material, is in the form of at least one of a monolith, a layer or sheet, a hollow or solid fiber, preferably a woven or nonwoven structure, a hollow or solid particle, or an extruded product, and preferably the solid carrier material preferably takes the form of essentially spherical beads.

9. The method according to any one of claims 1 to 8, wherein the solid carrier material, preferably in the form of a styrene-divinylbenzene-based carrier material or a styrene-allylamine carrier material, is in the form of solid particles embedded in a porous or non-porous matrix.

10. The method according to any one of claims 1 to 9, wherein the adsorbent material has a particle size (D50) in the range of 0.002 to 4 mm, 0.005 to 2 mm, 0.002 to 1.5 mm, 0.005 to 1.6 mm, or 0.01 to 1.5 mm, preferably in the range of 0.30 to 1.25 mm, and preferably in the form of essentially spherical beads.

11. The method according to any one of claims 1 to 10, wherein the reactant X is selected from the group consisting of halogens, tosylates, mesylates, esters, imides, carbodiimides, and pyrazoles.

12. An adsorbent material capable of reversibly binding carbon dioxide for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air (1), flue gas, and biogas, preferably for direct air recovery, particularly using a temperature, vacuum, or temperature / vacuum swing process, wherein the adsorbent material (3) can be obtained or is obtained using the method described in any one of claims 1 to 11.

13. The use of the sorbent material (3) according to claim 12 for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air (1), flue gas, and biogas, preferably for direct air recovery, particularly using a temperature, vacuum, or temperature / vacuum swing process, wherein the sorbent material (3) is, Immobilized on a solid carrier Primary amine portion, and At least one of the secondary amine moiety and the tertiary amine moiety Includes, use.

14. To separate gaseous carbon dioxide, at least the following sequential and repeated steps (a) to (e): (a) In the adsorption step, the gas mixture (1) is brought into contact with the sorbent material (3) under essentially ambient atmospheric pressure and ambient air temperature conditions, and at least the gaseous carbon dioxide is adsorbed onto the sorbent material (3) by flow-through through the unit (8), (b) A step of isolating the adsorbent material (3) having adsorbed carbon dioxide in the unit (8) from the flow-through, (c) A step of inducing a rise in the temperature of the sorbent material (3) to the temperature at which carbon dioxide desorption begins, (d) Extracting at least the desorbed gaseous carbon dioxide from the unit (8) and separating the gaseous carbon dioxide within the unit (8) or downstream of the unit (8), (e) A step of bringing the sorbent material (3) to essentially ambient atmospheric temperature and atmospheric pressure conditions. A method including the following is used: Use as described in claim 13.

15. A unit for separating gaseous carbon dioxide from a gas mixture, preferably from at least one of ambient air (1), flue gas, and biogas, preferably a direct air recovery unit, comprising at least one reactor unit (8) containing the sorbent material (3) according to claim 12 in a form suitable and adapted for the flow-through of the gas mixture (1), The reactor unit has an inlet for the gas mixture, preferably for ambient air (1), and an outlet (2) for the gas mixture, preferably for the ambient air being adsorbed. The reactor unit is capable of heating to a temperature of at least 60°C for the desorption of gaseous carbon dioxide, and the reactor unit is capable of opening to allow the gas mixture to flow through, preferably to ambient air, and to allow the gas mixture to come into contact with the sorbent material for the adsorption step, and preferably the reactor unit is capable of further evacuating to a vacuum pressure of 0.04 MPa (400 mbar) (absolute pressure) or less. The adsorbent material (3) preferably takes the form of at least a part of an adsorbent structure including an array of individual adsorbent elements, and each adsorbent element preferably has at least one carrier layer and at least one adsorbent material layer containing or consisting of at least one adsorbent material, Preferably, the adsorbent elements in the array are arranged essentially parallel to each other and spaced apart from each other to form parallel fluid passages for the flow through of the gas mixture, preferably ambient air and / or vapor. The unit comprises at least one device for separating carbon dioxide from water, preferably a condenser. Preferably, the apparatus for separating carbon dioxide from water, preferably the gas outlet side of the condenser, includes at least one, preferably both, of a carbon dioxide concentration sensor and a gas flow sensor for controlling the desorption process. unit.

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