Improving the speed of the gas capture process

Abstract

The present invention relates to a method for capturing CO2 from a gas stream, the method using a two-liquid phase capture composition.

Description

[Technical Field]

[0001] (Field of invention) The present invention relates to a method for capturing CO2 from a gas flow (or airflow or gas stream). The method uses a two-phase liquid capture composition (or two-phase liquid capture composition). [Background technology]

[0002] (Background of the invention) Climate change, a consequence of human activity, poses a threat to the health and well-being of billions of people worldwide. The 2015 Paris Agreement stipulated that the international community should keep the global temperature increase this century well below 2°C above pre-industrial levels, and pursue efforts to further limit the increase to 1.5°C. A significant contributor to climate change is the massive emissions of CO2 by many industries, particularly those generated from the combustion of fossil fuels or biofuels. Achieving the Paris Agreement requires a reassessment of our overall thinking (or approach) to global energy supply.

[0003] Carbon capture technologies enable the decarbonization of energy systems and industrial processes in a short period of time. In other words, by buying time, they can be replaced with carbon-neutral alternative systems or processes. Furthermore, variations such as BECCS (Biomass Energy with Carbon Capture & Storage) have the potential to promote negative CO2 emissions to offset emissions from areas (sectors) that cannot be easily decarbonized with current technologies (e.g., the aerospace industry).

[0004] WO2015 / 092427 describes a method of carbon capture using a composition comprising a mixture of miscible solvents. [Overview of the project]

[0005] (Summary of the invention) A first aspect of the present invention is a method for capturing CO2 from a gas flow (or airflow or gas stream) containing CO2. The method includes bringing a gas flow containing CO2 into contact with a capture composition (or capture composition) in a gas-liquid contactor to generate (or form) a filled capture composition (or filled, loaded or loaded capture composition). The capture composition comprises (i) a first liquid phase and (ii) a second liquid phase. (i) The first liquid phase comprises at least one capture reagent (or capture reagent or capture reagent). (ii) The second liquid phase is chemically inert with CO2. The second liquid phase is typically a solvent that is effective (or suitable) for CO2. The solubility (or solubility) of CO2 in the second liquid phase (e.g., physical solubility) may be higher than the solubility (e.g., physical solubility) of CO2 in the first liquid phase.

[0006] The first and second liquid phases are separate phases (or distinct or separated phases). That is, the capture composition comprises two liquid phases. The components contained in these two liquid phases and their relative amounts (the amount of such components present) are selected so that the capture composition comprises two liquid phases.

[0007] The present invention is due to some inventors' understanding of the physical processes (or steps) and chemical processes (or steps) of a CO2 capture mechanism (or CO2 capture mechanism). The first step of the capture mechanism (or capture mechanism) is to physically dissolve CO2 in a capture composition (or capture composition) containing a capture reagent (or capture reagent or capture reagent). When CO2 is physically dissolved in the capture composition, it can then undergo a chemical reaction with the capture reagent. The rate (or ratio or rate) at which CO2 dissolves in the capture composition is partially governed by the availability (or availability or utilization rate) of CO2 in the gas phase (or gas phase), i.e., its volume concentration (partial pressure). Therefore, it is partially governed by the availability of CO2 for dissolution / reaction at the gas-liquid interface.

[0008] The inventors have found that using two liquid phases improves the rate (or proportion or rate) of CO2 capture. While we do not wish to be bound by theory, by including (or incorporating) a second liquid phase that is a more effective solvent for CO2 than the first liquid phase, the physical elements of the capture mechanism can be slightly altered. However, significant changes can occur. In the presence of the second liquid phase, CO2 can first dissolve in the second liquid phase and can dissolve at a higher concentration than it would in the gas phase. It may then migrate to the first liquid phase, where it can react with the capture reagent. The overall effect of the second liquid phase may be that the capture reagent in the first liquid phase can more readily utilize the CO2, particularly at the liquid-liquid phase boundary. Thus, the overall rate (or proportion or rate) (or overall rate) of CO2 absorption is increased. Essentially, the second liquid phase may function as a means of concentrating CO2. Subsequently, the substance undergoes dissolution into a first liquid phase containing at least one capture reagent and reaction in the first liquid phase. Furthermore, the second phase may increase the surface area of ​​the first liquid phase exposed to CO2. This is crucial for fast reactions and kinetically improved mass transfer (or mass transfer). Here, the rate (or proportion or rate) (or mass transfer rate) of mass transfer becomes directly proportional to the surface area of ​​the interface. Furthermore, if the two liquid phases are partially miscible, the resistance of mass transfer at the interface can be further reduced by decreasing the resistance (or resistance) of the interface.

[0009] A second embodiment of the present invention provides a method for reacting a gas (or gaseous or gas stream) containing a gas (or gaseous or gas stream) with a reactive liquid (or reactive liquid or reactive liquid). The method includes contacting a gas stream containing a gas with a composition in a gas-liquid contact apparatus to produce (or form or generate or manufacture) a product composition (or product composition or product composition). The composition (i) a first liquid phase, and (ii) a second liquid phase . The first liquid phase contains a reagent (or reagent) for reacting with the gas. The second liquid phase is chemically inert (or inert) to the gas.

[0010] The second liquid phase is typically a solvent effective (or effective) for CO2. The solubility (or solubility or solubility) of CO2 in the second liquid phase may be higher than the solubility (or solubility or solubility) of CO2 in the first liquid phase.

[0011] The first liquid phase and the second liquid phase are separate phases (or separate phases or separated phases). That is, the composition comprises two liquid phases (or liquid phases). Therefore, the components (or components) contained in the two liquid phases and their relative amounts (the amounts in which these components are present) are selected such that the composition comprises two liquid phases (or liquid phases).

[0012] The principles (or principals) established by the inventors in the CO2 capture system are equally applicable to other gas-liquid reaction systems (or other gas-liquid reaction systems).

[0013] The first liquid phase and the second liquid phase may be immiscible. The first liquid phase and the second liquid phase may be partially miscible. When the first liquid phase and the second liquid phase are partially miscible, the first liquid phase and the second liquid phase are not completely miscible under the conditions of the gas-liquid contact step (or gas-liquid contact step) (i.e., temperature, pressure and the relative ratio (or proportion) of the two liquid phases).

[0014] Chemical reactions involving both gaseous and liquid (or solution) phase reagents are particularly challenging at the manufacturing scale because it is difficult to combine the various components of the reaction. To solve this problem, various gas-liquid contactors have been developed. These include, but are not limited to, packed columns (with irregular or regular packing and in co-flow, counter-flow, or cross-flow configurations), spray towers, plate columns or tray columns, stirred tank reactors (both continuous and batch configurations), tubular flow reactors (under both laminar and turbulent conditions), bubble column reactors, drip-film reactors, and membrane reactors. More recently developed are spinning disk reactors and rotating packed bed reactors.

[0015] For a given application, the selection criteria for choosing the optimal reactor are specific to that application, and designing against such criteria constitutes part of the process engineer's skills. Examples of definitive design criteria include, but are not limited to, minimizing the plant's capital costs, maximizing the plant's reaction yield efficiency, or minimizing the plant's electrical energy requirements (or demands). With regard to these appropriate applications, process enhancement is an active (or ongoing) area of ​​research and development in process engineering, as defined in “targeted improvement of a process at the unit operations, tasks and phenomena scales in order to increase process efficiency and improve sustainability” (Anantasarn N., Babi DK, Suriyaprapphadilok U., Gani R., Comput. Aided Chem. Eng., 2016, 38, 1093-1098, https: / / doi.org / 10.1016 / B978-0-444-63428-3.50187-9).

[0016] The gas-liquid contact process (or gas-liquid contact step) may be carried out at a total gas pressure (or total gas pressure) of 0.1 to 200 Bar (abs). The gas-liquid contact process (or gas-liquid contact step) may be carried out at a total gas pressure (or total gas pressure) of 0.1 to 100 Bar (abs). The gas-liquid contact process (or gas-liquid contact step) may be carried out at a total gas pressure (or total gas pressure) of 0.1 to 50 Bar (abs).

[0017] The gas-liquid contact process (or gas-liquid contact step) may be carried out at a temperature of 0 to 200°C. The gas-liquid contact process (or gas-liquid contact step) may be carried out at a temperature of 0 to 100°C. The gas-liquid contact process (or gas-liquid contact step) may be carried out at a temperature of 20 to 50°C.

[0018] The optimal proportion (or ratio or proportion) of the second liquid phase required to affect performance improvement depends on the manner (or method or manner) of the gas-liquid contact process. Typically, the second liquid phase is present in an amount ranging from 1 to 85% of the total volume (or total volume or overall volume or total volume or overall volume) of the composition (i.e., the captured composition). The second liquid phase may be present in an amount ranging from 10 to 70% of the total volume of the composition (i.e., the captured composition). The second liquid phase may be present in an amount ranging from 40 to 60% of the total volume of the composition (i.e., the captured composition). The second liquid phase may be present in an amount ranging from 20 to 50% of the total volume of the composition (i.e., the captured composition).

[0019] Therefore, the ratio of the first liquid phase to the second liquid phase may be in the range of 99:1 to 1:4 (volume) for the total volume of the composition (i.e., the captured composition). The ratio of the first liquid phase to the second liquid phase may be in the range of 9:1 to 1:3 (volume) for the total volume of the composition (i.e., the captured composition). The ratio of the first liquid phase to the second liquid phase may be in the range of 3:2 to 2:3 (volume) for the total volume of the composition (i.e., the captured composition). The ratio of the first liquid phase to the second liquid phase may be in the range of 4:1 to 1:1 (volume) for the total volume of the composition (i.e., the captured composition).

[0020] (CO2 capture) The above description applies to all methods described in the claims for reacting a gas from a gas flow (or airflow or gas stream) with a reactive liquid (including the CO2 capture method of the first aspect of the present invention). The following description relates in particular to the CO2 capture method of the first aspect of the present invention.

[0021] The first liquid phase may contain water. The first liquid phase may be an aqueous solution containing at least one capture reagent (or capture reagent or capture reagent).

[0022] At least one capture reagent (or capture agent or capture reagent) may be at least one salt of at least one carboxylic acid. The first liquid phase may be an aqueous solution of at least one salt of at least one carboxylic acid.

[0023] At least one salt of at least one carboxylic acid may be at least one metal salt. The metal cation may be selected from alkali metals, alkaline earth metals (i.e., Group 1 and Group 2 of the periodic table) and mixtures thereof. The carboxylic acid salt may be a salt of an alkali metal (e.g., lithium, sodium, or potassium). The carboxylic acid salt may be a potassium salt.

[0024] For the purposes of the present invention, salts of aliphatic, aromatic, or heteroaromatic (or heteroaromatic) carboxylic acids (e.g., salts of aliphatic or aromatic carboxylic acids) may be used. Suitable aliphatic carboxylic acids may be selected from linear, branched, or cyclic carboxylic acids. Such carboxylic acids may be saturated or unsaturated, and may be substituted or unsubstituted with substituents, heteroatoms (or heteroatoms), aromatic rings or heteroaromatic ring systems (or heteroaromatic ring systems). The carboxylic acid or each carboxylic acid may contain a single (or one or one) carboxylic acid group. Furthermore, polycarboxylic acids (e.g., di, tri, or tetracarboxylic acids) are suitable as polymer acids (or polymer acids) (e.g., polyacrylic acid and polymethacrylic acid) and carboxylic acids of naturally derived biopolymers (or biopolymers) (e.g., alginic acid (derived from seaweed) and pectin (derived from plant cell walls)). Salts of aromatic or heteroaromatic (or heteroaromatic) carboxylic acids (e.g., benzoic acid) are also suitable for the purposes of the present invention. Such salts may be in the form of solutions, slurries, or dispersions (or dispersions or liquid dispersions).

[0025] Typically, the above at least one carboxylic acid is at least one C1-C1 20The aliphatic carboxylic acid is, more typically, at least one C1-C8 aliphatic carboxylic acid or at least one C1-C6 aliphatic carboxylic acid. The aliphatic carboxylic acid(s) may be linear or branched. Examples of acids include acetic acid, propionic acid, butanoic acid (or butyric acid) (including both n-butyric acid (or n-butyric acid) and isobutyric acid (or isobutyric acid)), pentanoic acid (including both n-pentanoic acid and branched pentanoic acid (e.g., pivalic acid)), and hexanoic acid (including both n-hexanoic acid and branched hexanoic acid). In certain specific embodiments, the salt is a potassium salt of an aliphatic carboxylic acid, for example, a potassium salt of a C1-C6 aliphatic carboxylic acid which may be linear or branched.

[0026] The first liquid phase may contain a single salt of a carboxylic acid. The first liquid phase may contain a mixture of two or more salts of a carboxylic acid. If the first liquid phase contains a mixture of two or more salts, the two or more salts may contain the same cationic counterion (or counterion) (but are derived from different carboxylic acids). And / or, the two or more salts may be derived from the same carboxylic acid (but have various cationic counterions (or counterions)). The mixture may consist of at least one salt of a C1-C4 aliphatic carboxylic acid, which may be linear or branched, and at least one salt of a C5-C6 aliphatic carboxylic acid, which may be linear or branched. Both salts may be potassium salts of the carboxylic acids described above.

[0027] Aliphatic carboxylic acids, which may be linear or branched, may not be substituted with substituents (substituents containing complex atoms (or heteroatoms) (i.e., atoms other than C or H)). Aliphatic carboxylic acids may not be substituted with substituents containing nitrogen. However, aliphatic carboxylic acids may be substituted with substituents containing oxygen (e.g., hydroxyl groups, alkosy groups, or aryloxy groups). Lactic acid is an example. At least one of the above carboxylic acids may contain only carbon, hydrogen, and oxygen.

[0028] Furthermore, the carboxylic acid may not be an amino acid, or each carboxylic acid may not be an amino acid. The carboxylic acid may not contain nitrogen, or each carboxylic acid may not contain nitrogen. The capture composition may be substantially free of amino acids. The capture composition may be substantially free of nitrogen-containing organic compounds. The term "substantially free" may be interpreted as meaning that 25% by weight or less of the capture composition is an amino acid or a nitrogen-containing organic compound. It may also mean that 10% by weight or less of the capture composition is an amino acid or a nitrogen-containing organic compound. It may also mean that 5% by weight or less of the capture composition is an amino acid or a nitrogen-containing organic compound. It may also mean that 2% by weight or less of the capture composition is an amino acid or a nitrogen-containing organic compound. It may also mean that 1% by weight or less of the capture composition is an amino acid or a nitrogen-containing organic compound.

[0029] At least one capture reagent (or capture agent or capture reagent) (i.e., at least one salt of at least one carboxylic acid) may be present in the first liquid phase at a concentration in the range of 0.5 M to 15 M. At least one capture reagent (i.e., at least one salt of at least one carboxylic acid) may be present in the first liquid phase at a concentration in the range of 1 M to 15 M. At least one capture reagent (i.e., at least one salt of at least one carboxylic acid) may be present in the first liquid phase at a concentration in the range of 2 M to 15 M. At least one capture reagent (e.g., at least one salt of at least one carboxylic acid) may be present in the first liquid phase at a concentration in the range of 3 M to 12 M. At least one capture reagent (e.g., at least one salt of at least one carboxylic acid) may be present in the first liquid phase at a concentration in the range of 4 M to 9 M. These concentrations are in the first liquid phase (not in the capture composition as a whole).

[0030] The first liquid phase may contain an aqueous solution of at least one scavenger (or capture agent) (i.e., at least one salt of at least one carboxylic acid). The first liquid phase may contain an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid. The aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:15. The aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:12.5. The aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:10. The aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:7.5. The aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:5.

[0031] The first liquid phase may further contain a basic additive (or base additive).

[0032] Basic additives (or base additives) may be present in the first liquid phase at concentrations ranging from 1 M to 10 M. Basic additives may be present in the first liquid phase at concentrations ranging from 1.5 M to 6 M. Basic additives may be present in the first liquid phase at concentrations ranging from 2 M to 4 M. These concentrations are those in the first liquid phase (not in the overall capture composition).

[0033] A basic additive (or base additive) is a chemical species (or chemical species) that can deprotonate the carboxylic acid yielding the salt under conditions in which a CO2 capture reaction (or CO2 capture reaction) occurs. Therefore, a basic additive is a species (or chemical species or species) containing a conjugate acid having a higher pKa than the carboxylic acid yielding the salt under conditions in which a CO2 capture reaction occurs. The basic additive may have a pKa of 5 to 14 as measured in a dilute aqueous solution. In these embodiments, the carboxylic acid salt may be a salt of a C5-C8 aliphatic carboxylic acid, which may be linear or branched. The carboxylic acid salt may also be a potassium salt of a C5-C8 aliphatic carboxylic acid, which may be linear or branched.

[0034] The basic additive (or base additive) may be a salt. Therefore, the basic additive may not be a nitrogen base (i.e., it may not contain an amine).

[0035] The basic additive (or base additive) may be a carbonate (or carbonate salt or carbonate-salt). The carbonate may be an alkali metal or alkaline earth metal (i.e., Group 1 and Group 2 of the periodic table) carbonate (or carbonate) or a mixture thereof. The carbonate may be a potassium, sodium, lithium, magnesium, or calcium carbonate, or a combination thereof.

[0036] If the basic additive (or base additive) is a salt (e.g., a carbonate or a salt of phenol), the salt may contain the same cationic counterion (or counterion) as at least one salt of at least one carboxylic acid. The basic additive may also be a potassium salt.

[0037] The first liquid phase may further contain an enzyme. The enzyme facilitates the capture and / or release of carbon dioxide (CO2). The enzyme can facilitate the capture and / or release of carbon dioxide (CO2) by catalyzing the hydration of carbon dioxide to form carbonate and its salts (i.e., carbonates and bicarbonates) and / or by catalyzing the dehydration of carbonate and its salts (i.e., carbonates and bicarbonates) to form carbon dioxide. Therefore, the enzyme may be a carbonic anhydrase. The enzyme may be a natural (or native) carbonic anhydrase. The enzyme may be a carbonic anhydrase that has been manipulated (or designed or genetically modified) to optimize its performance as an accelerator in the capture composition. Examples of manipulated (or designed or genetically modified) carbonic anhydrases include those that have been chemically and biochemically modified from natural carbonic anhydrases. This may mean obtaining a natural enzyme and modifying it itself, or it may mean that the modified enzyme is produced (or generated or formed) from its constituent parts.

[0038] The enzyme may be present in the first liquid phase at a concentration within the range of 0.01 to 5 g / L (e.g., 0.5 to 1.5 g / L). This concentration is in the first liquid phase (not in the overall capture composition).

[0039] The first liquid phase may contain an ionic liquid (or ionic solution).

[0040] The first liquid phase does not necessarily have to be a single pure solvent, but may be a mixture of two or more compounds, as long as the mixture as a whole satisfies the above conditions. Depending on the properties (or characteristics or nature) or uniqueness (or identity or identity) of the first liquid phase, it may be necessary to incorporate other minor components to help control the capture process, such as antioxidants (or antioxidants) to prevent or reduce oxidative degradation of the first liquid phase components, or antifoaming agents (or anti-foaming agents) to prevent or reduce foaming of the first liquid phase in the gas-liquid contactor (or gas-liquid contactor). Suitable species (or chemical species or species) for these roles are well known to those skilled in the art; however, this does not form the basis of the present invention. The properties (or characteristics or nature), uniqueness (or identity or identity) and quantities of these minor components are specific to the use of capture and the uniqueness (or identity or identity) of the second liquid phase.

[0041] The solubility (or solubility or solubility) (e.g., physical solubility) of CO2 in the second liquid phase may be greater than the solubility (or solubility or solubility) (e.g., physical solubility) of CO2 in the first liquid phase.

[0042] The second liquid phase may contain at least one organic solvent. At least one organic solvent is selected to be immiscible or partially miscible with the first liquid phase. At least one organic solvent may contain only hydrogen atoms, silicon atoms, carbon atoms, and oxygen atoms, for example, only hydrogen atoms, carbon atoms, and oxygen atoms. At least one organic solvent may contain at least one oxygen atom. Examples of organic solvents that typically have high solubility (or solubility) in CO2 include: Ethers (including cyclic and acyclic ethers), polyethers (e.g., ethylene glycol ether, propylene glycol ether, and butylene glycol ether, and their alkylated derivatives), silicones / siloxanes (including cyclic and acyclic variants), hydrocarbons (e.g., alkanes, cycloalkanes, arenes, alkylated arenes, and their perfluorinated derivatives), and carbonyl compounds (e.g., esters, lactones, ketones, and aldehydes). At least one organic solvent may be selected from silicones, siloxanes, and ethers.

[0043] When the first liquid phase is an aqueous solution, the following are, but are not limited to, exemplary solvents suitable for use in the method of the present invention. 1,2-Dimethoxyethane, 1,2-Diethoxyethane, Ethylene glycol methyl ethyl ether, Diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, Diethylene glycol methyl ethyl ether, Triethylene glycol dimethyl ether, Triethylene glycol diethyl ether, Triethylene glycol methyl ethyl ether, 1,2-Dimethoxypropane, 1,2-Diethoxypropane, Dipropylene glycol dimethyl ether, Dipropylene glycol diethyl ether, Dipropylene glycol methyl ethyl ether, Tripropylene glycol dimethyl ether, Tripropylene glycol diethyl ether, Tripropylene glycol methyl ethyl ether, Di-isopropyl ether, Dibutyl ether, ethyl butyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, butyl acetate (or butyl acetate), pentyl acetate (or pentyl acetate), pentyl propionate (or pentyl propionate), hexyl propionate (or hexyl propionate), hexyl butyrate (or hexyl butyrate), heptyl butyrate (or heptyl butyrate), gamma(γ)-butyrolactone, gamma(γ)-octanolactone, 2-pentanone, 3-heptanone, 4-octanone, hexanal, heptanal, octanal, decanal.

[0044] The second liquid phase does not necessarily have to be a single pure solvent, but may be a mixture of two or more compounds, as long as the mixture as a whole satisfies the above conditions. Depending on the properties (or characteristics or nature) and uniqueness (or identity or identity) of the second liquid phase, other minor components may be added to help control the capture process in order to suppress foaming (or foaming), solvent degradation (or solvent degradation), corrosion (or corrosion), etc. The properties (or characteristics or nature), uniqueness (or identity or identity) and quantities of these minor components are specific to the use of capture (or capture) and the uniqueness (or identity or identity) of the first liquid phase.

[0045] Typically, the second liquid phase contains only components that are chemically inert to CO2 under the conditions under which the CO2 capture reaction takes place.

[0046] The capture composition may comprise (i) a first liquid phase and (ii) a second liquid phase. (i) The first liquid phase contains an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid. This aqueous solution has a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:15. (ii) The second liquid phase comprises a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R 1 -O-(CH2CHR 2 -O) n -R 3 (I) During the ceremony, R 1 and R 3 Each of these is independently an unsaturated C1-C4 alkyl group. R 2 These are independently selected from H and Me in each case, n is an integer selected from 1, 2, 3, and 4.

[0047] The capture composition (or capture composition) may include the following (iii) first liquid phase and (iv) second liquid phase. (iii) The first liquid phase includes an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid. This aqueous solution has a concentration such that the molar ratio of salt:water is within the range of 1:2.5 to 1:5. (iv) The second liquid phase includes a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R 1 -O-(CH2CHR 2 -O) n -R 3 (I) In the formula, R 1 and R 3 are each independently an unsaturated C1-C4 alkyl, R 2 is independently, in each case, selected from H and Me, n is an integer selected from 1, 2, 3, and 4.

[0048] To avoid doubt, the relative amounts of the components (or components) (salt, water, solvent or solvent of formula (I)) are such that the two liquids form separate phases.

[0049] The solvent of formula (I) may be partially soluble in water. Accordingly, the first phase may further include a solvent of formula (I) or a mixture of one or more solvents of formula (I). Accordingly, the first phase may be composed of water, an alkali metal salt of a C2-C5 carboxylic acid, and a solvent of formula (I) or a mixture of solvents of formula (I).

[0050] The alkali metal is preferably potassium.

[0051] The carboxylic acid is preferably a C3-C5 carboxylic acid (e.g., propionic acid, butyric acid (or butyric acid), or pentanoic acid). The carboxylic acid may be a C3-C4 carboxylic acid. The carboxylic acid may be propionic acid. The carboxylic acid may be butyric acid (or butyric acid) (e.g., isobutyric acid (or isobutyric acid)). The carboxylic acid may be unsubstituted with a functional group-containing heteroatom (or heteroatom) (e.g., O, N, S) (or may be unsubstituted).

[0052] R 2 In each case, R may be H. 2 In each case, it may be methyl.

[0053] R 1 and R 3 Each of these may independently be an unsubstituted (or not substituted) C1-C3 alkyl group. 1 and R 3 Each of these may independently be an unsubstituted (or not substituted) C2-C3 alkyl group. 1 and R 3 Each of these may be independently selected from methyl, ethyl, and propyl. 1 and R 3 Each of these may be independently selected from ethyl and propyl. 1 and R 3 They may be the same. 1 and R 3 These can be different. 1 and R 3 Each of these may be ethyl. 1 and R 3 Each of these may be propyl.

[0054] n may be an integer selected from 2 and 3. n may be 1. n may be 2. n may be 3. n may be 4.

[0055] The second liquid phase may be present in an amount ranging from 10 to 70% of the total volume of the composition (e.g., the capture composition). The second liquid phase may be present in an amount ranging from 40 to 60% of the total volume of the composition (i.e., the capture composition). The second liquid phase may be present in an amount ranging from 20 to 50% of the total volume of the composition (i.e., the capture composition).

[0056] The ratio of the first liquid phase to the second liquid phase may be in the range of 9:1 to 1:3 (volume) in terms of the total volume of the composition (e.g., the capture composition). The ratio of the first liquid phase to the second liquid phase may be in the range of 3:2 to 2:3 (volume) in terms of the total volume of the composition (e.g., the capture composition). The ratio of the first liquid phase to the second liquid phase may be in the range of 4:1 to 1:1 (volume) in terms of the total volume of the composition (e.g., the capture composition).

[0057] A gaseous stream (or airflow or gas stream) containing CO2 may contain emissions (or releases or emissions or discharges) from a combustion process (including, but not limited to, energy generation or industrial processes as combustion processes), or emissions (or releases or emissions) from a non-combustion industrial process.

[0058] Examples of such industrial processes include, but are not limited to, those in which carbon dioxide separation is an essential part of the process (e.g., natural gas removal (or sweetening) / purification, biogas reforming (or upgrading), hydrogen production, and synthesis gas production), as well as those in which carbon capture has been proposed as a means of mitigating the impact of the ongoing climate crisis (e.g., fermentation, iron and steel production, cement production, glass production, and aluminum melting).

[0059] The gaseous flow (or airflow or gas stream) containing CO2 may be obtained directly from the atmosphere.

[0060] The CO2-containing gaseous flow (or airflow or gas stream) may be obtained from a closed environment. Examples of closed environments include, but are not limited to, submarines and spacecraft.

[0061] Typically, contacting the above-mentioned capture composition with CO2 (or process or step) may be successfully achieved by passing a gas stream containing CO2 through the capture composition (e.g., using a bubble tray column) (or process or step), or by passing a gas stream containing CO2 through the capture composition in parallel (e.g., through a packed column) (or process or step), or by using any other process (or process or step) known to those skilled in the art.

[0062] The method may further include the following (or process or step): By heating the filled capture composition (or the filled, loaded, or captured capture composition) (or by process or step), the CO2 is released (or released by process or step), and / or, By subjecting the filled capture composition (or a filled, loaded or loaded capture composition) to a stream (or flow) of stripping gas (e.g., air), the CO2 is released (or released) (or the process or step), and / or To provide a stripped (or stripped) capture composition, the CO2 is released (or released) by reducing the pressure in (or above) the packed capture composition (or process or step). Furthermore, this process (or step) provides CO2.

[0063] The method may further include the following (or process or step): Regenerating the capture composition by cooling (or process or step) and / or by increasing the pressure in (or above) the stripped capture composition.

[0064] CO2 emissions (or releases) typically occur at temperatures ranging from 0°C to 300°C, most typically from 40°C to 200°C, for example, from 60°C to 150°C.

[0065] CO2 release is conventionally achieved at pressures in the range of 0 to 150 Bar. In specific embodiments, CO2 release may typically be achieved at pressures of about 1 to 5 Bar. In alternative embodiments using a pressurized system, CO2 release may typically occur at pressures in the range of 1 to 30 Bar(abs), most typically about 20 Bar(abs). In some embodiments, CO2 release occurs at pressures in the range of 0 to 1 Bar(abs).

[0066] In certain embodiments of the present invention, the first liquid phase is not separated from the second liquid phase. Subsequently, a step is taken to release CO2 from the packed capture composition (or the packed, loaded, or loaded capture composition). Therefore, in certain embodiments, the phase separation step is not performed in the packed capture composition (or the packed, loaded, or loaded capture composition). Subsequently, a step is taken to release CO2. To avoid any doubt, when releasing CO2 from the packed capture composition (or the packed, loaded, or loaded capture composition), both the first and second liquid phases are present.

[0067] In other embodiments of the present invention, the phase separation step may be performed in a filled capture composition (or a filled, loaded, or absorbed capture composition). Subsequently, a CO2 release step is performed. This step includes separating the first liquid phase from the second liquid phase. The CO2 release step is then performed in the first liquid phase only. The second liquid phase may be mixed with fresh first liquid phase or with a regenerated first liquid phase. It may be recycled into an absorber (or adsorption or absorption device). Such embodiments may reduce the energy consumption of the CO2 release step. This is achieved by reducing the mass of the liquid that needs to be heated to the CO2 release temperature.

[0068] A particularly useful aspect of this technology is that in closed systems and / or pressurized systems (those capable of increasing pressure), the release process generates carbon dioxide (CO2). This should reduce the requirement for further compression in storage applications. It has significant implications for the reduction of overall energy consumption in complete capture and storage processes.

[0069] By applying (or imparting) heat, the captured gas is released from the capture composition, thereby promoting the regeneration of the capture composition. This allows it to be used for further capture and release operations (or operation) involving additional CO2 during cooling.

[0070] Releasing captured CO2 from a capture composition by applying a stream of stripping gas (e.g., air) does not require further regeneration of the solvent (such a solvent can then be recycled for further capture and release operations). Releasing captured CO2 via a stream of stripping gas may be further enhanced by the application of heat.

[0071] In a desorption device (or desorption device or desorption device), releasing captured CO2 from a capture composition (or capture composition) by reducing pressure does not require further regeneration of the capture composition (or capture composition can then be recycled (or reused or circulated)) (except for returning the solvent to its adsorption pressure). In a CO2 release device (or CO2 release device), releasing captured CO2 by reducing pressure may be further enhanced (or improved) by applying (or providing) heat.

[0072] A third embodiment of the present invention provides a CO2 scavenging composition (or CO2 capture composition) comprising (i) a first liquid phase and (ii) a second liquid phase. (i) The first liquid phase contains an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid. This aqueous solution has a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:15. (ii) The second liquid phase comprises a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R 1 -O-(CH2CHR 2 -O) n -R 3 (I) During the ceremony, R 1 and R 3 Each of these is independently an unsaturated C1-C4 alkyl group. R 2 These are independently selected from H and Me in each case, n is an integer selected from 1, 2, 3, and 4.

[0073] The CO2 capture composition of the third aspect of the present invention may be any of the capture compositions described above with respect to the first aspect of the present invention.

[0074] In particular, in a third aspect of the present invention, the first liquid phase may contain an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid, and the aqueous solution may have a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:5.

[0075] The present invention is further illustrated by the numbered items (or claims) as follows:

[0076] 1. A method for capturing CO2 from a gas stream containing CO2, the method comprising bringing a gas stream containing CO2 into contact with a capture composition (or capture composition) in a gas-liquid contactor (or process or step) to generate a filled capture composition (or a filled, loaded or loaded capture composition or capture composition). The capture composition comprises (i) a first liquid phase and (ii) a second liquid phase. (i) The first liquid phase comprises at least one capture reagent (or capture reagent or capture reagent). (ii) The second liquid phase is a solvent that is effective against CO2 and is chemically inert towards CO2. The motion of the captured composition passing through the gas-liquid contact device is induced in such a way that it experiences an acceleration of 5 g or less.

[0077] 2. The method according to paragraph 1, wherein the step of bringing a gas flow into contact with a capture composition is performed in a gas-liquid contactor, the gas-liquid contactor being selected from a packed column (having irregular or regular packing and having a co-flow, counter-flow or cross-flow configuration), a spray tower, a plate column or tray column, a stirred tank reactor (either in a continuous or batch configuration), a tubular flow reactor (either under laminar or turbulent conditions), a bubble column reactor, a falling membrane reactor or a membrane contactor.

[0078] 3. A method according to paragraph 1 or 2, wherein the first liquid phase comprises an aqueous solution of at least one salt of at least one carboxylic acid.

[0079] 4. A method according to paragraph 3, wherein the cation of at least one salt of at least one carboxylic acid is an alkali metal, an alkaline earth metal or a mixture thereof.

[0080] 5. A method according to paragraph 3 or 4, wherein at least one carboxylic acid comprises only carbon, hydrogen, and oxygen.

[0081] 6. A method according to any one of paragraphs 3 to 5, wherein at least one carboxylic acid is at least one C1-C8 aliphatic carboxylic acid.

[0082] 7. A method according to paragraph 6, wherein at least one carboxylic acid corresponding to a salt of at least one carboxylic acid is selected from a list comprising acetic acid, propanoic acid, butyric acid and its branched derivatives, pentanoic acid and its branched derivatives, hexanoic acid and its branched derivatives, heptanoic acid and its branched derivatives, and octanoic acid and its branched derivatives.

[0083] 8. A method according to any one of paragraphs 1 to 7, wherein the first liquid phase further comprises at least one carbonate (or carbonate salt or carbonate-salt).

[0084] 9. A method according to paragraph 8, wherein at least one carbonate is selected from a list comprising alkali metal carbonates, alkaline earth metal carbonates, or mixtures thereof.

[0085] 10. A method according to any one of paragraphs 1 to 9, wherein the first liquid phase further comprises an enzyme.

[0086] 11. A method according to paragraph 10, wherein the enzyme is a natural carbon anhydrase or an engineered (or designed or genetically modified) carbon anhydrase.

[0087] 12. A method according to any one of paragraphs 1 to 11, wherein at least one capture reagent is present in the first liquid phase at a concentration in the range of 2 M to 15 M.

[0088] 13. A method according to any one of paragraphs 1 to 12, wherein the second liquid phase is an organic solvent.

[0089] 14. A method according to paragraph 13, wherein the second liquid phase is selected from a list comprising silicones / siloxanes and ethers.

[0090] 15. The method according to paragraph 13, wherein the second liquid phase is 1,2-dimethoxypropane, 1,2-diethoxypropane, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether A method in which a solvent is selected from triethylene glycol methyl ethyl ether, di-isopropyl ether, dibutyl ether, ethyl butyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, butyl acetate, pentyl acetate, pentyl propionate, hexyl propionate, hexyl butyrate, heptyl butyrate, gamma(γ)-butyrolactone, gamma(γ)-octanolactone, 2-pentanone, 3-heptanone, 4-octanone, hexanal, heptanal, octanal, and decanal.

[0091] 16. A method according to any one of paragraphs 1 to 15, wherein the ratio of the first liquid phase to the second liquid phase may be in the range of 1:3 to 9:1 (volume).

[0092] 17. A method according to any one of paragraphs 1 to 16, wherein the solubility (or solubility or solubility) of CO2 in the second liquid phase is higher than that of CO2 in the first liquid phase.

[0093] 18. A method according to any one of paragraphs 1 to 17, wherein the gas stream (or airflow or gas stream) containing CO2 includes emissions (or discharges or emissions or releases or emissions) from a combustion process (or combustion process or combustion process).

[0094] 19. A method for reacting a gas (or gaseous fluid) from a gaseous flow (or gaseous flow or gas stream) containing a gas (or gaseous liquid or reactive liquid) with a reactive liquid (or reactive liquid or reactive liquid), the method comprising contacting a gaseous flow containing a gas with a composition in a gas-liquid contactor (or process or step) for generating (or forming or generating or manufacturing) a product composition (or manufactured composition or product composition). The composition comprises (i) a first liquid phase and (ii) a second liquid phase. (i) The first liquid phase contains a reagent (or reagent) for reacting with the gas. (ii) The second liquid phase is an effective (or effective) solvent for the gas and is chemically inert (or inert) for the gas. The motion of the captured composition passing through the gas-liquid contact device is induced in such a way that it experiences an acceleration of 5 g or less.

[0095] 20. A method according to paragraph 19, wherein the solubility (or solubility or solubility) of the gas in the second liquid phase is higher than that of the gas in the first liquid phase.

[0096] twenty one. A method according to paragraph 19 or 20, wherein the step of bringing a gas flow into contact with a capture composition is performed in a gas-liquid contactor, the gas-liquid contactor being selected from a packed column (having irregular or regular packing and having a co-flow, counter-flow or cross-flow configuration), a spray tower, a plate column or tray column, a stirred tank reactor (either in a continuous or batch configuration), a tubular flow reactor (either under laminar or turbulent conditions), a bubble column reactor, a bottom-flow membrane reactor or a membrane contactor.

[0097] twenty two. A method for capturing CO2 from a gaseous flow (or gaseous flow or gas stream) containing CO2, the method comprising bringing a gaseous flow containing CO2 into contact with a capture composition (or capture composition) in a gas-liquid contactor to generate a filled capture composition (or a filled, loaded or loaded capture composition). The capture composition comprises (iii) a first liquid phase and (iv) a second liquid phase capture composition (or second liquid phase capture composition). (iii) The first liquid phase comprises at least one capture reagent (or capture reagent or capture reagent). (iv) The second liquid phase capture composition may include (v) the first liquid phase and (vi) the second liquid phase. (v) The first liquid phase contains an aqueous solution of an alkali metal salt of a C2-C5 aliphatic carboxylic acid. This aqueous solution has a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:5. (vi) The second liquid phase contains a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R 1 -O-(CH2CHR 2 -O) n -R 3 (I) During the ceremony, R 1and R 3 Each of these is independently an unsaturated C1-C4 alkyl group. R 2 These are independently selected from H and Me in each case, n is an integer selected from 1, 2, 3, and 4. [Brief explanation of the drawing]

[0098] [Figure 1] Figure 1 shows the CO2 absorption rate (or CO2 absorption rate) as a function of the Reynolds number for Example 11. [Modes for carrying out the invention]

[0099] (Detailed description of the invention) The term "alkyl" refers to a linear or branched hydrocarbon chain. For example, the term "C 1-6 "Alkyl" refers to a linear or branched hydrocarbon chain containing 1, 2, 3, 4, 5, or 6 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl). Alkyl groups may be unsubstituted (or not substituted).

[0100] The term "aliphatic carboxylic acid" refers to a carboxylic acid containing CO2H bonded to an alkyl group. It may also refer to a carboxylic acid containing CO2H bonded to an unsubstituted alkyl group.

[0101] For chemical reactions in a liquid phase containing one or more gaseous reagents (or gaseous reagents or gas reagents), the rate (or proportion or rate) of the reaction may be governed, at least in part, by the availability (or availability or utilization rate) of the gaseous reagent(s) in the liquid phase. According to Henry's Law, the equilibrium concentration of a gas (or gas) physically dissolved in a liquid phase is proportional to the partial pressure above the liquid. The proportionality constant (or proportional factor or proportionality constant) is called the Henry's Law constant. In other words, the physical solubility (or solubility or solubility) of a gas (or gas) in a liquid phase is the concentration of the gas (in the gas phase) multiplied by several values ​​(Henry's Law constants) (taking into account the properties of the gas species, the properties of the liquid phase, and the temperature (the temperature at which the measurement is being taken)).

[0102] Regarding applications of carbon capture, the concentration of CO2 in the gas stream to be treated depends on the nature of the process that generates the gas stream. For many potential applications of carbon capture technology, the gas stream to be treated is a product of an air-breathing combustion process. As a result, it may contain relatively small amounts of CO2 (Table 1). Even exhaust gases from activities where carbon is likely to be highly concentrated have relatively low volume concentrations of CO2 (e.g., coal-fired power plants (Table 1, Entry 4) or cement manufacturing (Table 1, Entry 8)). Capturing CO2 from such sources may be technically challenging. It may require the use of large absorbers (or adsorption or absorption devices). It may increase the capital cost of the capture plant. Alternatively, it may increase the enhancement of mechanical processes. It may increase the energy penalty of the capture process.

[0103] [Table 1]

[0104] As used herein, a solvent effective against CO2 means a solvent having a Henry's Law constant for CO2 such that the equilibrium volume concentration of CO2 found in the solvent at a given partial pressure of CO2 is greater than the volume concentration of CO2 found in the gas phase at the same partial pressure. The critical value of Henry's Law constant can be calculated to be approximately 0.041 mol / L / Bar at 20°C (Table 2). In this situation, a solvent with a Henry's Law constant greater than this value can be considered an effective solvent against CO2. A solvent with a Henry's Law constant smaller than this value may not be considered an effective solvent against CO2.

[0105] [Table 2]

[0106] The versatility of this approach for various combinations of first and second liquid phases is demonstrated by the use of various examples, as described below. All such examples were performed in our laboratory using a vapor-liquid equilibria (VLE) apparatus consisting of a stainless steel vessel (stirred, jacketed) equipped with temperature and pressure sensors. The composition to be tested is brought to the test temperature in the vessel, and CO2 at a predetermined partial pressure is added to the gas space above the composition. CO2 is supplied from another reservoir whose temperature and pressure are monitored. The partial pressure of CO2 in the reaction vessel is maintained by a regulator. From the temperature and pressure data of the CO2 reservoir, recorded as a function of time, the rate of CO2 absorption and the total amount (or total) of CO2 absorbed can be calculated. For each of the following examples, an organic solvent was added, consisting of salt(s) and water in the desired ratio, until the second liquid phase appeared. This composition was then run (or tested) twice in the VLE apparatus. For the first trial, a single-phase composition was used in which the organic solvent was present in an amount sufficient to completely dissolve it in the salt solution. For the second trial, a composition containing the organic solvent was used (forming a second liquid phase, and in an amount sufficient to dissolve the organic solvent in the salt solution). In all cases, the operation (or test) was performed with the composition having two liquid phases (1:1 liquid-phase ratio (volume)). The absorption rate was reported as "moles of absorbed CO2 / 1 liter of composition / partial pressure of CO2 at 1 bar / 1 hour". [Examples]

[0107] Example 1 Potassium propionate and water (molar ratio 1:3) were combined with methyl isobutanoate (or methyl isobutyrate). In single-phase absorption experiments, a maximum absorption rate of 2 mol / L / Bar / h was observed. In two-liquid-phase absorption experiments, a maximum absorption rate of 5 mol / L / Bar / h was observed.

[0108] Example 2 Potassium acetate and water (molar ratio 1:3) were combined with diethylene glycol dimethyl ether. In single-phase absorption experiments, a maximum absorption rate of 2.5 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 6.5 mol / L / Bar / h was observed.

[0109] Example 3 7M potassium acetate (in water) was combined with methyl isobutanoate (or methyl isobutyrate). In single-phase absorption experiments, a maximum absorption rate of 2 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 6.5 mol / L / Bar / h was observed.

[0110] Example 4 Potassium acetate and water (molar ratio 1:3) were combined with polymethylhydrosiloxane. In single-phase absorption experiments, a maximum absorption rate of 1.5 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 4.5 mol / L / Bar / h was observed.

[0111] Example 5 Potassium propionate and water (molar ratio 1:3.25) were combined with 2-pentanone. In single-phase absorption experiments, a maximum absorption rate of 4 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 8 mol / L / Bar / h was observed.

[0112] Example 6 Potassium propionate and water (molar ratio 1:3.25) were combined with butyl acetate. In single-phase absorption experiments, a maximum absorption rate of 4 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 8 mol / L / Bar / h was observed.

[0113] Example 7 Potassium propionate and water (molar ratio 1:3.25) were combined with cyclohexanone. In single-phase absorption experiments, a maximum absorption rate of 2.5 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 5.5 mol / L / Bar / h was observed.

[0114] Example 8 Potassium propionate and water (molar ratio 1:3.25) were combined with diethylene glycol diethyl ether. In single-phase absorption experiments, a maximum absorption rate of 0.5 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 7 mol / L / Bar / h was observed.

[0115] Example 9 Potassium propionate and water (molar ratio 1:3.25) were mixed with ethyl acetate. In single-phase absorption experiments, a maximum absorption rate of 4 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 6.5 mol / L / Bar / h was observed.

[0116] Example 10 0.6 M potassium hexanoate (in water) and 4 M potassium carbonate (in water) were combined with cyclohexanone. In single-phase absorption experiments, a maximum absorption rate of 3.5 mol / L / Bar / h was observed. In two-phase absorption experiments, a maximum absorption rate of 6 mol / L / Bar / h was observed.

[0117] Example 11 This final embodiment provided herein can demonstrate that the effect is universal over a wide range of stirring speeds, i.e., mechanical inputs. In this final embodiment, the experiment was performed in the same manner as in Examples 1-10, except that the absorption was performed multiple times and the stirring speed was varied between runs. The Reynolds number was calculated for each run, and a graph (Figure 1) showing the maximum absorption rate (expressed as mol / L / Bar / h as above) was plotted as a function of the Reynolds number. As can be seen, the accelerating effect of the second liquid phase is universal over a wide range of stirring speeds / Reynolds numbers. Note that the axis of the graph is logarithmic, and even at the highest Reynolds number achievable with our apparatus (Re = approximately 10,000), the absorption rate to the two-phase system was approximately twice that to the single-phase system.

[0118] The composition (or composition) used in this final example had a molar ratio of potassium propionate to water of 1:3.25, and butyl acetate was used as the second liquid phase. The disclosures in this specification may include the following aspects: (Aspect 1) CO 2 CO from a gas stream containing 2 A method for capturing CO, wherein in order to generate a filled capture composition, a gas-liquid contact device is used 2 The process includes bringing a gas stream containing a capture composition into contact with the capture composition. The aforementioned capture composition (iii) First liquid phase, and (iv) Second liquid phase Includes, The first liquid phase comprises at least one capture reagent, The second liquid phase is CO 2 It is an effective solvent for CO 2 It is chemically inert to it. The first liquid phase comprises an aqueous solution of at least one salt of at least one carboxylic acid, The method further involves the CO2 from the packing and capturing composition. 2 Including the release of method. (Aspect 2) The method according to embodiment 1, wherein the step of bringing the gas flow into contact with the capture composition is performed in a gas-liquid contactor, the gas-liquid contactor being selected from a packed column (having irregular or regular packing and having a co-flow, counter-flow or cross-flow configuration), a spray tower, a plate column or tray column, a stirred tank reactor (either in a continuous or batch configuration), a tubular flow reactor (either under laminar or turbulent flow conditions), a bubble column reactor, a falling membrane reactor or a membrane contactor. (Aspect 3) The method according to embodiment 1 or 2, wherein the cation of at least one salt of the at least one carboxylic acid is an alkali metal, an alkaline earth metal, or a mixture thereof. (Aspect 4) The method according to embodiment 3, wherein the at least one carboxylic acid comprises only carbon, hydrogen, and oxygen. (Aspect 5) The at least one carboxylic acid is at least one C 1 ~C 8 The method according to embodiment 3 or 4, wherein the aliphatic carboxylic acid is... (Aspect 6) The method according to embodiment 5, wherein the at least one carboxylic acid corresponding to a salt of the at least one carboxylic acid is selected from a list including acetic acid, propanoic acid, butyric acid and its branched derivatives, pentanoic acid and its branched derivatives, hexanoic acid and its branched derivatives, heptanoic acid and its branched derivatives, and octanoic acid and its branched derivatives. (Aspect 7) The method according to any one of embodiments 1 to 6, wherein the first liquid phase further comprises at least one carbonate. (Pattern 8) The method according to embodiment 7, wherein the at least one carbonate is selected from a list including alkali metal carbonates, alkaline earth metal carbonates, or mixtures thereof. (Aspect 9) The method according to any one of embodiments 1 to 8, wherein the first liquid phase further comprises an enzyme. (Aspect 10) The method according to embodiment 9, wherein the enzyme is a natural carbon anhydrase or an engineered carbon anhydrase. (Aspect 11) The method according to any one of embodiments 1 to 10, wherein at least one capture reagent is present in the first liquid phase at a concentration in the range of 2 M to 15 M. (Aspect 12) The method according to any one of embodiments 1 to 11, wherein the second liquid phase is an organic solvent. (Aspect 13) The method according to embodiment 12, wherein the second liquid phase is selected from a list comprising silicones / siloxanes and ethers. (Aspect 14) The second liquid phase is 1,2-dimethoxypropane, 1,2-diethoxypropane, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol The method according to embodiment 12, wherein the solvent is selected from methyl ethyl ether, di-isopropyl ether, dibutyl ether, ethyl butyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, butyl acetate, pentyl acetate, pentyl propionate, hexyl propionate, hexyl butyrate, heptyl butyrate, gamma(γ)-butyrolactone, gamma(γ)-octanolactone, 2-pentanone, 3-heptanone, 4-octanone, hexanal, heptanal, octanal, and decanal. (Aspect 15) The method according to any one of embodiments 1 to 14, wherein the ratio of the first liquid phase to the second liquid phase may be within the range of 1:3 to 9:1 (by volume). (Aspect 16) CO in the second liquid phase 2 The physical solubility of CO in the first liquid phase is 2 The method according to any one of embodiments 1 to 15, wherein the physical solubility is higher than that of [the specified method]. (Aspect 17) The aforementioned CO 2 The gas stream containing the gaseous flow includes emissions from the combustion process, according to any one of embodiments 1 to 16. (Aspect 18) The aforementioned CO 2 teeth, (i) heating the filling and trapping composition, and / or (ii) Exposing the packing and trapping composition to a stream of stripping gas (e.g., air), and / or (iii) To provide a stripped capture composition, reduce the pressure above the packing capture composition. The method according to any one of embodiments 1 to 17, which is released by... (Aspect 19) CO 2 CO from a gas stream containing 2 A method for capturing CO, wherein in order to generate a filled capture composition, a gas-liquid contact device is used 2 The process includes bringing a gas stream containing a capture composition into contact with the capture composition. The aforementioned capture composition (v) First liquid phase, and (vi) Second liquid phase Includes, The first liquid phase is C 2 ~C 5 The solution contains an aqueous solution of an alkali metal salt of an aliphatic carboxylic acid, wherein the aqueous solution has a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:15. The second liquid phase is a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R 1 -O-(CH 2 CHR 2 -O) n -R 3 (I) [In the formula, R 1 and R 3 Each of these is independently an unsaturated C 1 ~C 4 It is an alkyl group, R 2 These are independently selected from H and Me in each case, n is an integer selected from 1, 2, 3, and 4. Methods that include... (Aspect 20) The method according to embodiment 19, wherein the molar ratio of the salt to the water is in the range of 1:2.5 to 1:5.

Claims

1. CO ２ CO from a gas stream containing ２ A method for capturing CO, wherein in a gas-liquid contact apparatus, to generate a filled capture composition, ２ The process includes bringing a gas stream containing a capture composition into contact with the capture composition. The aforementioned capture composition (i) First liquid phase, and (ii) Second liquid phase Includes, The first liquid phase comprises an aqueous solution of at least one capture reagent, The second liquid phase is CO ２ It is an effective solvent for CO ２ It is chemically inert to it. The at least one capture reagent is at least one salt of at least one carboxylic acid, The method further involves the CO2 from the packing and capturing composition. ２ This includes releasing The ratio of the first liquid phase to the second liquid phase is within the range of 1:3 to 9:1 (by volume). method.

2. The method according to claim 1, wherein the step of bringing the gas flow into contact with the capture composition is performed in a gas-liquid contactor, and the gas-liquid contactor is selected from a packed column, a spray tower, a plate column or tray column, a stirred tank reactor, a tubular flow reactor, a bubble column reactor, a drip membrane reactor or a membrane contactor.

3. The method according to claim 1 or 2, wherein the cation of at least one salt of the at least one carboxylic acid is an alkali metal, an alkaline earth metal, or a mixture thereof.

4. The method according to claim 3, wherein the at least one carboxylic acid comprises only carbon, hydrogen, and oxygen.

5. The at least one carboxylic acid is at least one C １ ~C ８ The method according to claim 3 or 4, wherein the aliphatic carboxylic acid is...

6. The method according to claim 5, wherein the at least one carboxylic acid corresponding to a salt of the at least one carboxylic acid is selected from a list including acetic acid, propanoic acid, butyric acid and its branched derivatives, pentanoic acid and its branched derivatives, hexanoic acid and its branched derivatives, heptanoic acid and its branched derivatives, and octanoic acid and its branched derivatives.

7. The method according to any one of claims 1 to 6, wherein the first liquid phase further comprises at least one carbonate.

8. The method according to claim 7, wherein the at least one carbonate is selected from a list including alkali metal carbonates, alkaline earth metal carbonates, or mixtures thereof.

9. The method according to any one of claims 1 to 8, wherein the first liquid phase further comprises an enzyme.

10. The method according to claim 9, wherein the enzyme is a natural carbon anhydrase or an engineered carbon anhydrase.

11. The method according to any one of claims 1 to 10, wherein the at least one capture reagent is present in the first liquid phase at a concentration in the range of 2 M to 15 M.

12. The method according to any one of claims 1 to 11, wherein the second liquid phase is an organic solvent.

13. The method according to claim 12, wherein the second liquid phase is selected from a list comprising silicones / siloxanes and ethers.

14. The second liquid phase is 1,2-dimethoxypropane, 1,2-diethoxypropane, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol The method according to claim 12, wherein the solvent is selected from methyl ethyl ether, di-isopropyl ether, dibutyl ether, ethyl butyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, butyl acetate, pentyl acetate, pentyl propionate, hexyl propionate, hexyl butyrate, heptyl butyrate, gamma(γ)-butyrolactone, gamma(γ)-octanolactone, 2-pentanone, 3-heptanone, 4-octanone, hexanal, heptanal, octanal, and decanal.

15. The physical solubility of CO in the second liquid phase ２ is higher than the physical solubility of CO in the first liquid phase ２ The method according to any one of claims 1 to 14.

16. The aforementioned CO ２ The method according to any one of claims 1 to 15, wherein the gas flow including includes emissions from the combustion process.

17. The aforementioned CO ２ teeth, (i) Heating the packing and trapping composition, and / or (ii) The packing and trapping composition is subjected to a stream of stripping gas, and / or (iii) To provide a stripped capture composition, reduce the pressure above the filled capture composition. The method according to any one of claims 1 to 16, wherein the material is released by...

18. CO ２ CO from a gas stream containing ２ A method for capturing CO, wherein in a gas-liquid contact apparatus, to generate a filled capture composition, ２ The process includes bringing a gas stream containing a capture composition into contact with the capture composition. The aforementioned capture composition (i) First liquid phase, and (ii) Second liquid phase Includes, The first liquid phase is C ２ ~C ５ The solution contains an aqueous solution of an alkali metal salt of an aliphatic carboxylic acid, wherein the aqueous solution has a concentration such that the molar ratio of salt to water is in the range of 1:2.5 to 1:

15. The second liquid phase is a solvent of the following formula (I) or a mixture of one or more solvents of the following formula (I). R １ -O-(CH ２ CHR ２ -O) ｎ -R ３ (I) [In the formula, R １ and R ３ Each of these is independently an unsaturated C １ ~C ４ It is an alkyl group, R ２ These are independently selected from H and Me in each case, n is an integer selected from 1, 2, 3, and 4. Includes, The ratio of the first liquid phase to the second liquid phase is within the range of 1:3 to 9:1 (by volume). method.

19. The method according to claim 18, wherein the molar ratio of the salt to the water is in the range of 1:2.5 to 1:5.

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