Methods for binding, transporting, activating reactions, converting, storing, and releasing water-soluble gases

Abstract

The present invention provides a novel method for binding or absorbing gaseous elements or elemental molecules or gaseous compounds, particularly acidic gases, especially carbon dioxide, in an aqueous medium, and subsequently storing them, as well as for recovering pure gaseous elements or elemental molecules or gaseous compounds, especially carbon dioxide. [Solution] The present invention provides an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group, wherein the aqueous acceptor solution is brought into contact with a gas containing carbon dioxide to bind the carbon dioxide in the acceptor solution. The acceptor solution containing the bound carbon dioxide obtained thereby is stored in an aqueous medium to selectively transport the bound carbon dioxide to an aqueous medium by passing it through a separation membrane, and the carbon dioxide is released in a concentrated state using electrodialysis. Furthermore, a carbon compound that becomes a valuable recovered product is generated by reacting the carbon dioxide with the compound.

Description

Detailed description of the invention

[0001] The present invention relates to a method for the selective binding, selective membrane transport, and storage of carbon dioxide (CO2) in an aqueous medium. The method of the present invention comprises providing an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group, and contacting the aqueous acceptor solution with a gas containing carbon dioxide to bind the carbon dioxide in the acceptor solution. The acceptor solution containing the thereby bound carbon dioxide is useful for storing carbon dioxide in an aqueous medium, releasing carbon dioxide, and for use in electrochemical methods such as electrodialysis, for selective transport of the bound carbon dioxide through a separation membrane to an aqueous medium. The present invention further relates to the preparation of carbonates and bicarbonates starting from an acceptor solution containing bound carbon dioxide.

[0002] [Conventional technology] Gaseous elements, elemental molecules, or gaseous molecular compounds are highly sought-after starting materials for chemical synthesis. Therefore, attempts are made to obtain these elements, elemental molecules, or compounds in their pure form, often requiring considerable technical effort or energy investment. In the prior art, methods for recovering industrial gases by separation using separation membranes are known. In the case of air mixtures, the gaseous elements, elemental molecules, or gaseous molecular compounds to be separated are usually present at very low concentrations. Separation efficiency is typically not within the desired range, especially when the relevant elements, elemental molecules, or gaseous molecular compounds differ only slightly from one another in terms of their physicochemical properties.

[0003] In the case of gaseous elements, elemental molecules, or gaseous molecular compounds that can be incorporated into a liquid, separation of gaseous elements, elemental molecules, or gaseous molecular compounds that are not incorporated / dissolved in the liquid, or are incorporated / dissolved in small amounts, is possible. This is especially true when gaseous elements, elemental molecules, or gaseous molecular compounds in an aqueous medium cause the dissociation of water molecules, forming water-soluble compounds of the gaseous elements, elemental molecules, or gaseous compounds, such as acidic forms. This is true, for example, when there are gaseous compounds of carbon and oxygen, or sulfur and oxygen, such as carbon dioxide (CO2) or sulfur dioxide (SO2), where, for example, carbonic acid or sulfuric acid is formed in an aqueous medium at low concentrations. These gaseous molecular compounds, such as carbon dioxide (CO2) or sulfur dioxide (SO2), cause the dissociation of water molecules in an aqueous medium, forming water-soluble acidic forms, also known as acidic gases in the prior art. Ionic or ionized compounds, such as salts, can be separated together with or from a liquid. Regarding separation from aqueous media, methods such as electrodialysis using a suitable membrane are known in the prior art. Electrodialysis is a method for separating ions in a saline solution. Desalting, separation, and concentration in salts, acids, and bases are possible applications of electrodialysis. The separation of the desired ions is achieved by an anode and a cathode, and an electric field applied through an ion-exchange membrane or a semipermeable ion-selective membrane. Thus, electrodialysis is an electrochemically driven membrane method, in which an ion-exchange membrane is used in combination with a potential difference to separate ionic compounds from, for example, uncharged solvents or impurities.

[0004] For example, electrodialysis machines are known from prior art, consisting of an alternating arrangement of anion exchange membranes and cation exchange membranes placed between two electrodes, where externally attached electrodes are separated from the membrane and surrounded in a separation chamber by a conductive aqueous electrode solution that is electrolyzed. Hydrogen gas is produced at the cathode and oxygen gas is produced at the anode. The problem is that, for example, if the concentration of a water-soluble gaseous compound dissolved in a liquid or gaseous compound that chemically reacts with water upon contact, such as carbonic acid or sulfur dioxide, is low, the electrophoretic separation performance in the electrochemical method of electrodialysis is limited, and there is energy loss due to the electrolysis of water molecules that occurs simultaneously during electrodialysis. Furthermore, there is usually the problem that the receiving medium, i.e., the medium in which the compound to be separated, or its reaction products with water, are concentrated, must be water-based to establish electrical conductivity, and the separated compound, or its reaction products with water, must first be returned to a gaseous state for use. Therefore, in the prior art, there is no method for selectively transporting a gas or gaseous compound to another aqueous medium (receiving medium) to first dissolve it in an aqueous medium and then recover it as a gaseous phase, or to release it again as a gas or gaseous compound.

[0005] A well-known method for purifying biogas from sulfur and carbon dioxide is so-called pressurized water scrubbing. In pressurized water scrubbing, water and raw biogas are purified under pressure in an absorption device using countercurrent principles, thereby separating the gas and any small amount of methane present, which dissolves in the scrubbing solution. However, subsequent material utilization, such as CO2, is not possible with pressurized water scrubbing.

[0006] Another well-known method for separating carbon dioxide, hydrogen sulfide, and other acidic gases from gaseous mixtures in natural gas processing is so-called amine scrubbing. In amine scrubbing, amines, such as slightly alkaline aqueous solutions of diethanolamine and monoethanolamine, as well as methyldiethanolamine, diisopropylamine, diisopropanolamine, and diglycolamine, can be used to reversibly chemisorb (adsorb) acidic gaseous components. The gas to be purified is usually introduced into the amine aqueous solution at a pressure of about 8 bar and a temperature of about 40°C. When CO2 is absorbed into the amine / water mixture, the CO2 first dissolves in the water, forming carbonic acid. The formed carbonic acid first dissolves in H + and HCO 3- It decomposes into ions. These can then react with amines, so the absorbed CO2 chemically reversibly binds to form a carbamate that can be redissolved in a desorption apparatus. In the desorption apparatus, the chemical equilibrium is reversed at high temperature and low pressure, thus removing and releasing the bound acidic gas from the amine solution. However, amine scrubbing has certain drawbacks, as the amines used in this method are harmful to health and are considered the third leading cause of workplace-related cancers.

[0007] Therefore, on the one hand, there is a great need for a method to dissolve or absorb gaseous elements or elemental molecules or gaseous compounds, particularly carbon dioxide, in an aqueous liquid, and to ionize or make them ionizable, and then pass them through a separation membrane by a diffusion or electrophoretic step, and transfer them to a further aqueous medium (receiving medium), thereby separating the gaseous and / or reactive compounds of the separated compound, which are present in the aqueous medium and react with other elements or elemental molecules or compounds, or are released as gas from the aqueous medium and separated. Preferably, the solubility and ionizability of the gaseous elements or elemental molecules or gaseous compounds should be increased by this method to enable energy-efficient transport of the compounds to be separated.

[0008] Therefore, the object of the present invention is to provide a novel method for binding or absorbing gaseous elements or elemental molecules or gaseous compounds, particularly acidic gases, particularly carbon dioxide (CO2), in an aqueous medium, and subsequently storing them, as well as for recovering pure gaseous elements or elemental molecules or gaseous compounds, particularly carbon dioxide (CO2). Therefore, the object of the present invention relates to providing a method for dissolving / binding / transporting / reacting / chemically transforming and selectively releasing water-soluble gaseous compounds, particularly carbon dioxide.

[0009] This problem is solved according to the present invention as described in the technical teachings of the independent claims. Further advantageous embodiments of the present invention are derived from the dependent claims, specification, drawings, and examples.

[0010] [explanation] Surprisingly, it has become clear that the problem can be solved by providing an aqueous acceptor medium comprising an organic acceptor compound having at least one amidino group and / or guanidino group and simultaneously exhibiting hydrophilicity. This has proven to enable the dissolution / binding / transport / reaction activation / chemical transformation, as well as selective release, of water-soluble gaseous compounds. In this context, water solubility means that a gaseous substance / gas compound chemically reacts with water and, upon contact with water, forms, for example, an acid anhydride or acid. The acid anhydride or acid then exists in water as an organic or inorganic acid, or, after dissociation in water, as a corresponding anion.

[0011] When a gaseous compound is brought into contact with water, a water-soluble reaction product can be formed. In the case of carbon dioxide, the reaction with water produces bicarbonate (HCO3). - ) and carbonate (CO3 2- This leads to the formation of ) which are later also called carbon dioxide derivatives.

[0012] In the prior art, it is known that the solubility in water of gaseous elements, elemental molecules, or gaseous compounds that react with water to form water-soluble derivatives can be increased by using an alkaline solution. This is particularly true for acidic gases such as carbon dioxide or sulfur dioxide.

[0013] In the prior art, alkaline solutions of alkali metals and alkaline earth metals, such as aqueous solutions of sodium hydroxide or potassium hydroxide, are used to prepare alkaline solutions. Using these compounds to dissolve and absorb gaseous compounds in an aqueous medium leads to the formation of carbonates or bicarbonates (salts of carbonate) in the presence of carbon dioxide, which precipitate as solids such as calcium carbonate, which are substantially insoluble in water. This is undesirable when recovering the gaseous compounds that have migrated to the aqueous solution in a pure gaseous state.

[0014] Compounds containing tertiary or quaternary nitrogen compounds, such as ammonia, which are suitable for creating a basic environment in an aqueous medium, are also known from the prior art to improve the solubility of gases and gaseous compounds in aqueous media. The drawback here is that the tertiary or quaternary nitrogen compounds present in the prior art are electrokinetically transported toward the cathode in aqueous solutions under a DC electric field. Therefore, they are not suitable for electrophoretic separation, such as in electrochemical processes like electrodialysis.

[0015] Surprisingly, it has been shown that by using basic amino acids dissolved in an aqueous acceptor medium, it is possible to promote the reaction between gases / gas compounds and water, resulting in the formation of water-soluble compounds of gases / gas compounds. Basic amino acids as used herein are defined as amino acids having an amino group or N atom with a free electron pair in the amino acid residue (side chain). When these N atoms accept a proton, a positively charged side chain is formed. The amino acids histidine, lysine, and arginine belong to the category of basic amino acids. Preferably, according to the present invention, a basic amino acid having at least one guanidino group and / or amidino group is used, such as arginine. When using aqueous solutions of amino acids having at least one guanidino group and / or amidino group, readily soluble in an aqueous medium, and accepting or capable of accepting protons present dissociated in aqueous solution, and when their dissolution in water establishes a basic pH and a gas or gas mixture is brought into contact with the acceptor solution, it has been demonstrated that very rapid uptake of gaseous carbon dioxide occurs in the solution. It was also revealed that one bicarbonate anion or carbonate anion is bound to each dino group. Surprisingly, when the pH of the solution is >8, the dissociation rate of the bound bicarbonate anion or carbonate anion becomes very low, and therefore, pressurizing the aqueous acceptor medium with a gas consisting of or containing carbon dioxide is not necessary to rapidly and completely bind the carbonate anion / bicarbonate anion. Thus, water-soluble compounds having one or more free guanidino groups and / or free amidino groups can be used, on the one hand, to achieve very good dissolution or absorption of carbon dioxide in an aqueous medium, and at the same time, to ensure very stable binding of carbonate anions / bicarbonate anions to free guanidino groups / free amidino groups. These properties of the acceptor medium according to the present invention have shown that it can also be used to dissolve and bind other organic and inorganic gas / gas compounds, such as hydrogen sulfide gas or chlorine gas, etc. In this way, the absorption capacity of gas / gas mixtures that are soluble in water and react with water to form water-soluble compounds can be greatly increased. In particular, the ability of water to uptake carbon dioxide can be significantly increased by the presence of water-soluble compounds having one or more free guanidino groups and / or free amidino groups. Therefore, uptake into aqueous media, reaction with water, and binding of carbon dioxide and carbon dioxide derivatives in water are increased or accelerated.

[0016] Therefore, it was revealed that compounds containing at least one free guanidino group and / or free amidino group have reaction-promoting and binding properties for carbon dioxide and carbon dioxide derivatives (carbonate anions / bicarbonate anions) in water. The physicochemical interactions between carbon dioxide or carbon dioxide derivatives in water and compounds containing at least one free guanidino group and / or free amidino group give compounds containing at least one free guanidino group and / or free amidino group acceptor properties that enable both dissolution and binding in water, as well as reaction promotion and chemical transformation, and further preservation of carbon dioxide or carbon dioxide derivatives. Therefore, compounds containing free guanidino groups and / or free amidino groups are hereafter referred to as acceptor compounds, and the medium in which at least one compound containing at least one free guanidino group and / or free amidino group is present is hereafter referred to as an acceptor medium.

[0017] Therefore, an aqueous solution containing at least one compound having at least one free guanidino group and / or a free amidino group, and present in a soluble form, can be used to provide an acceptor solution.

[0018] Preferably as described herein, the method involves increasing the solubility of a gaseous compound in an aqueous acceptor medium, i.e., an acceptor solution. Particularly preferably as described herein, the method involves the gaseous compound being carbon dioxide. According to the present invention, an aqueous acceptor medium, i.e., an acceptor solution comprising at least one acceptor compound having free guanidino groups and / or free amidino groups, is provided, which has the technical effect of increasing the solubility of a gaseous compound, in particular carbon dioxide. In this context, the term solubility refers to the dissolution of water-soluble gases that chemically react with water upon contact, such as acidic gases that form acids or weak acids when dissolved in water.

[0019] Preferably, the present invention provides an aqueous acceptor solution comprising at least one acceptor compound having at least one free guanidino group and / or a free amidino group, and a method of contacting this with a gas or gas mixture. Therefore, the present invention relates more specifically to providing an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group, and a method of contacting the aqueous acceptor solution with a gas or gas mixture containing carbon dioxide in order to bind carbon dioxide from the gas or gas mixture.

[0020] Preferably, the method involves contacting an aqueous acceptor medium, i.e., an acceptor solution, with a gas / gas mixture containing at least one gaseous compound that dissolves in water to form an acid and / or anion, wherein the at least one gaseous compound that dissolves in water to form an acid and / or anion is bound by at least one acceptor compound present in the acceptor medium, i.e., the acceptor solution.

[0021] Preferably, the present invention provides a method for increasing the solubility and binding of a gas that forms an acid / anionic compound in water and / or exists in an anionic form, i.e., an acidic gas, in an aqueous acceptor medium, wherein at least one acceptor compound is present, and the at least one acceptor compound is a hydrophilic organic compound having at least one amidino group and / or guanidino group. Preferably, the present invention provides a method for anionically binding the gaseous compound in the aqueous acceptor medium to the acceptor compound. Anionic means that the bound gaseous compound dissociates in the acceptor solution and exists as an anion in the aqueous solution, and the acceptor compound is protonated to form a counterion. According to the present invention, the acceptor compound has a free guanidino group and / or amidino group that can be protonated to provide a cation as a counterion to the anion of the gaseous compound in the acceptor solution.

[0022] Therefore, the method of the present invention includes at least the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; and b) Bring a gas containing carbon dioxide into contact with the acceptor solution from step a).

[0023] Preferably, the method involves at least one hydrophilic organic compound having at least one amidino group and / or guanidino group being present in an aqueous acceptor medium to dissolve, neutralize and bind a gaseous compound that forms an acid upon contact with water or exists in an anionic form as herein, and / or to contact and react the compound with other compounds, or to selectively release the bound gas as a gas. Preferably, the method involves at least one hydrophilic organic compound having at least one amidino group and / or guanidino group being present in an aqueous acceptor medium to dissolve, neutralize and bind an acidic gas, particularly carbon dioxide. Furthermore, the aqueous acceptor medium containing the bound acidic gas, particularly carbon dioxide, can be contacted with other compounds to convert the bound acidic gas, particularly carbon dioxide, for example, to convert it into a carbonate or bicarbonate that is insoluble or sparingly soluble in water in the case of carbon dioxide, or to selectively release the bound acidic gas, particularly carbon dioxide, as a gas, particularly gaseous carbon dioxide.

[0024] Therefore, the present invention relates to a method for selectively binding to and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contact a gas containing carbon dioxide with the acceptor solution from step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

[0025] A preferred embodiment includes the following step c): c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b) at atmospheric pressure.

[0026] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution of step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution of step b) through a separation membrane to an aqueous uptake and release medium.

[0027] As an alternative formulation, the present invention thus relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, comprising the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) bringing a gas containing carbon dioxide into contact with the acceptor solution of step a); and c) transporting the carbonate anions / bicarbonate anions in the acceptor solution of step b) through a separation membrane to an aqueous incorporation and release medium.

[0028] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium. c2) Releasing carbon dioxide as a gaseous phase from the intake and release medium containing the bound carbon dioxide / carbon dioxide derivative in step c).

[0029] As an alternative formulation, the present invention thus relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, comprising the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the carbonate anion / bicarbonate anion in the acceptor solution in step b) to the aqueous uptake and release medium by passing it through a separation membrane. c2) Releasing carbon dioxide as a gaseous phase from the intake and release medium containing carbonate anions / bicarbonate anions in step c).

[0030] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Bring the acceptor solution in step b) containing the bound carbon dioxide / carbon dioxide derivative into contact with the reaction compound.

[0031] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Bringing a gas containing carbon dioxide into contact with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; and d2) Add the reaction compound to the uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c).

[0032] As an alternative formulation, the present invention thus relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, comprising the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the carbonate anion / bicarbonate anion in the acceptor solution in step b) to the aqueous uptake and release medium by passing it through a separation membrane. d2) Add the reaction compound to the incorporation and release medium containing the carbonate anion / bicarbonate anion from step c).

[0033] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or, Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

[0034] As an alternative formulation, the present invention thus relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, comprising the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or The bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) is transported through a separation membrane to an aqueous uptake and release medium.

[0035] The present invention therefore relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or, Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and c2) Releasing carbon dioxide as a gaseous phase from an incorporation and emission medium containing bound carbon dioxide / carbon dioxide derivative from step c); or d2) Add the reaction compound to the uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c).

[0036] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; and c2) Releasing carbon dioxide as a gaseous phase from the incorporation and emission medium containing the bound carbon dioxide / carbon dioxide derivative in step c); or d2) Add the reaction compound to the uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c).

[0037] Preferably, the method involves dissolving carbon dioxide in an aqueous medium to form a carbonate anion / bicarbonate anion, in which a stable physicochemical bond of the obtained carbonate anion / bicarbonate anion in an aqueous acceptor medium is simultaneously established.

[0038] Preferably, the dissolution of carbon dioxide, and the bonding of the carbonate anion / bicarbonate anion formed by the dissolution of carbon dioxide, are brought about via free guanidino groups and / or free amidino groups in the aqueous acceptor medium.

[0039] Preferably, the water-soluble acceptor compound is a compound having a free guanidino group and / or a free amidino group that accepts or can accept at least one proton when dissolved in water.

[0040] Preferably, the water-soluble acceptor compound is an amino acid having at least one guanidino group and / or amidino group, and is capable of binding to or accepting at least one proton in an aqueous medium.

[0041] Preferably, the water-soluble acceptor compound for dissolving carbon dioxide, and for binding and transporting carbon dioxide or carbon dioxide derivatives and the carbonate anions / bicarbonate anions formed thereby in water, is arginine and / or an arginine derivative.

[0042] Particularly preferred, and therefore, the method is in which at least one acceptor compound having a free guanidino group and / or a free amidino group is an arginine derivative, or most preferably arginine. Acceptor solutions containing at least one arginine derivative, or most preferably arginine, have been shown to be particularly advantageous and effective for the binding and storage of carbon dioxide in an aqueous medium.

[0043] Surprisingly, it has been shown that the method of the present invention makes it possible to completely remove carbon dioxide contained in a gas mixture from the gas mixture. Complete removal means that after contacting a gas mixture containing carbon dioxide with an acceptor solution, the carbon dioxide content in the treated gas / gas mixture is <1 ppm. .

[0044] Contact between a gas or gas mixture and an aqueous acceptor medium can be carried out by various process embodiments known in the prior art. For example, contact between the two phases may be achieved by introducing the gas phase into the liquid phase, or by passing the gas phase over a surface moistened with the liquid phase. In preferred method embodiments, methods are used to bring the gas phase and the liquid phase into contact, resulting in a very large interface between the phases. These are carried out in devices such as homogenizers / dynamic mixers, as well as in static mixers and packed gas scrubbing devices.

[0045] Preferably, this method involves bringing a gas / gas mixture into contact with an acceptor medium. Preferably, the method involves contact between the gas / gas mixture and the acceptor medium, where the carbon dioxide content is completely dissolved in the acceptor medium and then bonded there.

[0046] Preferably, the gas / gas mixture is brought into contact with an acceptor medium so that some of the carbon dioxide present and / or the reaction products of carbon dioxide and water are completely bonded by the acceptor compound.

[0047] A preferred method is one in which a large interface is established between the aqueous acceptor medium and the gaseous phase containing carbon dioxide. In particular, a major advantage of the stable bonding between free guanidino groups and / or free amidino groups and carbonate / bicarbonate anions is that, despite high concentrations of dissolved carbon dioxide in the acceptor medium, re-dissociation into a gaseous state does not occur, and therefore, pressurization of the acceptor medium is not required to maintain high concentrations of dissolved carbon dioxide or the reaction products with water.

[0048] Preferably, the dissolution and binding of carbon dioxide and carbon dioxide derivatives is carried out without pressurizing the acceptor solution. Preferably, the dissolution and binding of carbon dioxide is carried out under atmospheric pressure. Preferably, the dissolution and binding of carbon dioxide is achieved without overpressure. According to the standard, the mean atmospheric pressure at sea level is 101,325 Pa = 101.325 kPa = 1013.25 hPa ≈ 1 bar. Preferably, the dissolution and binding of carbon dioxide occurs at normal pressure. Preferably, the dissolution and binding of carbon dioxide is achieved at a normal pressure of 101.325 kPa. Preferably, the dissolution and binding of carbon dioxide is carried out without pressurization.

[0049] A preferred embodiment of the method according to the present invention includes the following step b): b) A gas containing carbon dioxide is brought into contact with the acceptor solution from step a), where the contact in step b) is carried out at normal pressure or atmospheric pressure.

[0050] A preferred embodiment of the method according to the present invention includes the following step b): b) A gas containing carbon dioxide is brought into contact with the acceptor solution from step a), where the contact in step b) is carried out at atmospheric pressure.

[0051] A preferred embodiment of the method according to the present invention includes the following step b): b) The gas containing carbon dioxide is brought into contact with the acceptor solution of step a), where the contact in step b) is carried out at atmospheric pressure.

[0052] A preferred embodiment of the method according to the present invention includes the following step b): b) The gas containing carbon dioxide is brought into contact with the acceptor solution of step a), where the contact in step b) is carried out without pressurization.

[0053] A preferred embodiment of the method according to the present invention includes the following step b): b) The gas containing carbon dioxide is brought into contact with the acceptor solution from step a), where the contact in step b) is carried out without pressurization.

[0054] Here, contact at normal pressure, atmospheric pressure, or without pressurization means that the acceptor solution is provided under normal pressure, atmospheric pressure, or without pressurization.

[0055] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b). Includes, Here, the contact in step b) is at atmospheric pressure, and / or, here, the acceptor solution from step c) is stored at atmospheric pressure. A preferred embodiment is, here, the contact in step b) is at atmospheric pressure; and here, the acceptor solution from step c) is stored at atmospheric pressure.

[0056] Preferably, the present invention relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or In step b), the bound carbon dioxide / carbon dioxide derivative in the acceptor solution is transported through a separation membrane to an aqueous uptake and release medium. Includes, Here, the contact in step b) is performed at atmospheric pressure, and / or, here, the acceptor solution from step c) is stored at atmospheric pressure. A preferred embodiment is here, the contact in step b) is performed at atmospheric pressure, and here, the acceptor solution from step c) is stored at atmospheric pressure.

[0057] This aspect of the present invention provides even more particularly advantageous effects with respect to further method embodiments. For example, carbon dioxide absorbed in an acceptor solution, or its reaction products with water, can be stored without loss for >6 months without pressure (i.e., not pressurized), i.e., without positive pressure, or at atmospheric or normal pressure. Thus, a non-corrosive acceptor solution containing bound carbon dioxide, or its reaction products with water, can be stored without hazard and transported in containers. Here, transport means transferring the acceptor solution containing bound carbon dioxide to a transportable container, such as a large tank, container, or barrel. Suitable transport containers for transporting liquids are well known to those skilled in the art. Here, hazardless storage and transport involve passing the bound carbon dioxide / carbon dioxide derivative in the acceptor solution containing bound carbon dioxide through a separation membrane for aqueous incorporation and release. This does not refer to transport to a medium. Therefore, transporting bound carbon dioxide / carbon dioxide derivatives in an acceptor solution containing bound carbon dioxide through a separation membrane to an aqueous uptake and release medium may also be referred to as membrane transport in this specification.

[0058] Preferably, the dissolution and bonding of the reaction product of gaseous carbon dioxide with water occurs without pressurizing the acceptor solution. Preferably, the dissolution and bonding of the reaction product of gaseous carbon dioxide with water into the acceptor solution occurs at atmospheric pressure or normal pressure. Preferably, the contact between the gas containing carbon dioxide and the acceptor solution occurs without pressure (i.e., without pressurization). Preferably, the contact between the gas containing carbon dioxide and the acceptor solution occurs at atmospheric pressure.

[0059] Preferably, the storage and / or transport (in a transport container) of the acceptor solution containing dissolved and bound carbon dioxide, or its reaction products with water, is carried out without pressure. Preferably, the storage and / or transport (in a transport container) of the acceptor solution containing dissolved and bound carbon dioxide, or its reaction products with water, is carried out at atmospheric pressure.

[0060] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store and / or transport the acceptor solution containing bound carbon dioxide from step b), Includes, Here, preferably in this specification, the contact in step b) is carried out at atmospheric pressure, and / or here the acceptor solution from step c) is stored and / or transported at atmospheric pressure in a storage container and / or transport container.

[0061] Furthermore, in a preferred embodiment, the contact in step b) is carried out at atmospheric pressure, and the acceptor solution from step c) is stored or transported at atmospheric pressure in a storage container and / or transport container.

[0062] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or Store and / or transport the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b), Includes, Here, preferably in this specification, the contact in step b) is carried out at atmospheric pressure, and / or here the acceptor solution from step c) is stored and / or transported in a storage container and / or transport container at atmospheric pressure. More preferably here the contact in step b) is carried out at atmospheric pressure, and here the In this embodiment, the acceptor solution from step c) is stored or transported at atmospheric pressure in a storage container and / or transport container.

[0063] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store and / or transport the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or In step b), the bound carbon dioxide / carbon dioxide derivative in the acceptor solution is transported through a separation membrane to an aqueous uptake and release medium. Includes, Here, preferably in the present specification, the contact in step b) is carried out at atmospheric pressure, and / or here, the acceptor solution from step c) is stored and / or transported in a storage container and / or a transport container at atmospheric pressure. More preferably, here, the contact in step b) is carried out at atmospheric pressure, and here, the acceptor solution from step c) is stored or transported in a storage container and / or a transport container at atmospheric pressure, which is an embodiment.

[0064] However, when the acceptor medium is brought into contact with a gas / gas mixture containing carbon dioxide while pressurizing the gas / gas mixture, the amount of carbon dioxide dissolved and bound per unit time can be increased.

[0065] Therefore, in another preferred embodiment, the concentration or saturation of an aqueous acceptor solution containing a guanidino group- and / or amidino group-containing compound with dissolved carbon dioxide is carried out in a concentration device that allows pressurization. By this, it is achieved that the acceleration of concentration or the acceleration of reaching the saturation point is enabled. The presence of saturation of the acceptor medium with carbon dioxide can be detected, for example, by an increase in the concentration of carbon dioxide in the gas mixture discharged through the concentration device. Surprisingly, in an aqueous acceptor medium, when the free guanidino group and / or free amidino group of the acceptor compound is in excess compared to the carbon dioxide molecules in the gas / gas mixture, it has been revealed that there is a complete or almost complete depletion of carbon dioxide when the gas phase contacts the acceptor medium for a sufficiently long time. In this context, almost complete means a concentration / portion of <= 100 ppm. In this regard, the method is directed to the complete or almost complete extraction of carbon dioxide from the gas / gas mixture.

[0066] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group in a concentrator that enables pressurization; b) The gas containing carbon dioxide is brought into contact with the acceptor solution in step a), where the contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide.

[0067] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or, Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b). Includes, Here, the acceptor solution in step a) is provided in a concentrator that enables pressurization; and The contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide.

[0068] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or In step b), the bound carbon dioxide / carbon dioxide derivative in the acceptor solution is transported through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution in step a) is provided in a concentrator that enables pressurization; and The contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide.

[0069] Preferably, the method involves contacting a gas / gas mixture containing carbon dioxide with an acceptor solution until the gas reaches a carbon dioxide concentration of <100 ppm. Preferably, the method involves contacting a gas / gas mixture containing carbon dioxide with an acceptor solution until the carbon dioxide concentration in the gas reaches <100 ppm, where the contact is carried out under pressure.

[0070] Preferably, the method involves contacting a gas containing carbon dioxide with an acceptor solution until the concentration of gaseous carbon dioxide reaches <100 ppm, wherein the number of free guanidino groups and / or free amidino groups of the acceptor compound is in excess of the number of carbon dioxide molecules present in the gas / gas mixture.

[0071] However, as shown below, the method can also be used to convert the extracted and bound carbon dioxide, as well as its derivatives. For this purpose, it is advantageous when the concentration / content of carbon dioxide and / or carbon dioxide derivatives in the water is as high as possible. Therefore, as specified herein, it is preferable to contact the acceptor medium with a gas / gas mixture containing or consisting of carbon dioxide until further uptake is no longer achieved, i.e., until the acceptor medium is saturated with carbon dioxide. This can be recognized, for example, by the fact that the carbon dioxide content in the gas / gas mixture contacted with the acceptor medium increases again to, for example, >100 ppm. Thus, the absorption capacity of the acceptor medium is exhausted, and the absorption... The opter medium is saturated with carbon dioxide.

[0072] Preferably, the acceptor medium is saturated with carbon dioxide and / or carbonate anions and / or bicarbonate anions, wherein the contact between the acceptor medium and the gas / gas mixture is carried out until the concentration of carbon dioxide in the gas / gas mixture in contact with the acceptor medium increases to >100 ppm.

[0073] Preferably, the acceptor medium is saturated with carbon dioxide. In a preferred embodiment, the acceptor solution saturated with carbon dioxide is obtained in step b) of the method according to the present invention.

[0074] In a preferred embodiment, a depressurization step is performed following a concentration step in which a pressure increased relative to atmospheric pressure is applied to the gas / gas mixture to saturate the acceptor medium, in which degassing is achieved of dissolved gaseous compounds, such as nitrogen, oxygen, or methane, which are not intended to be separated or may interfere with reaction steps occurring in further steps, under atmospheric pressure or only slightly increased or decreased pressure. Surprisingly, it has been shown that even when a negative pressure of 100 mbar is applied, carbon dioxide or its reaction products with water are not desorbed or released from the solution after saturation of the aqueous acceptor medium with carbon dioxide, however this has been achieved under high pressure. In a preferred embodiment, after contact of the aqueous acceptor medium with the gas / gas mixture containing carbon dioxide, achieved at atmospheric pressure or overpressure, the removal of gaseous compounds other than carbon dioxide from the aqueous acceptor medium is brought about by depressurizing the aqueous acceptor medium to atmospheric pressure and / or by applying negative pressure. In a preferred embodiment, gases / gaseous components other than carbon dioxide, or their reaction products with water, are removed from the aqueous acceptor medium by depressurization or by applying reduced pressure (negative pressure).

[0075] In this embodiment, selective separation of carbon dioxide is preferably carried out following the expansion step. Preferably, the gas / gas mixture is brought into contact with an aqueous acceptor medium under atmospheric pressure or high pressure, and then gases / gas components that do not correspond to carbon dioxide are released or extracted in an expansion step carried out under atmospheric pressure or negative pressure.

[0076] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group in a concentrator that enables pressurization; b) bringing a gas containing carbon dioxide into contact with the acceptor solution in step a), where the contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide; and b') Depressurize the acceptor solution from step b) containing the bound carbon dioxide / carbon dioxide derivative at atmospheric pressure or under reduced pressure.

[0077] If formulated as an alternative, the present invention thus relates to a method for selectively binding and storing carbon dioxide in an aqueous medium, comprising the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group in a concentrator that enables pressurization; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a) under pressure; and b') Expose the acceptor solution from step b) containing the bound carbon dioxide / carbon dioxide derivative to atmospheric pressure or reduced pressure.

[0078] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or, Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b). Includes, Here, the acceptor solution in step a) is provided in a concentrator that enables pressurization; and The contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide. Here, the method further includes the following step b') after step b): b') Depressurize the acceptor solution from step b) containing the bound carbon dioxide / carbon dioxide derivative at atmospheric pressure or under reduced pressure.

[0079] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b); and / or In step b), the bound carbon dioxide / carbon dioxide derivative in the acceptor solution is transported through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution from step a) is provided in a concentrator that enables pressurization; and The contact in step b) is carried out under pressure, preferably until the acceptor solution is saturated with carbon dioxide. Here, the method further includes the following step b') after step b): b') Depressurize the acceptor solution from step b) containing the bound carbon dioxide / carbon dioxide derivative at atmospheric pressure or under reduced pressure.

[0080] In a preferred embodiment, after contacting a gas / gas mixture containing carbon dioxide with an acceptor solution, the carbon dioxide dissolved in the aqueous acceptor medium, or the reaction product thereof with water, is released as a gaseous phase.

[0081] Generally, electrolysis involves conducting a direct current through a conductive liquid (electrolyte) via two electrodes. At the electrodes, the electrolytic reaction products are produced from substances contained in the electrolyte. Surprisingly, it was found that by applying a DC voltage to an aqueous acceptor medium to which carbon dioxide has been added, carbon dioxide was released at both electrodes in the form of bubbles. This suggests that the total content of (bound) carbon dioxide, or its reaction products with water, is concentrated in the aqueous aqueous acceptor medium. This reveals that it allows for removal / emission from the scepter medium.

[0082] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c1) Release carbon dioxide as a gaseous phase from the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

[0083] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c1) By applying a DC voltage to the acceptor solution from step b), carbon dioxide is released as a gaseous phase from the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

[0084] Therefore, a preferred embodiment relates to a method for selectively binding to and releasing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) bringing a gas containing carbon dioxide into contact with the acceptor solution from step a); and c1) By electrolysis, carbon dioxide is released as a gaseous phase from the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

[0085] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and includes the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; and c2) By applying a DC voltage to the aqueous intake and release medium in step c), carbon dioxide is released as a gaseous phase from the intake and release medium containing the bound carbon dioxide / carbon dioxide derivative in step c).

[0086] Preferably, the method involves loading carbon dioxide by bringing an aqueous acceptor medium into contact with carbon dioxide, and then releasing the carbon dioxide dissolved / bound in the acceptor medium, or the reaction product thereof with water, as carbon dioxide gas by applying a DC voltage to the acceptor medium.

[0087] As expected, in addition to carbon dioxide, oxygen is released at the anode and hydrogen at the cathode. Surprisingly, by then using electrophoresis, the carbonate anions / bicarbonate anions present in the acceptor solution are spatially separated, and then carbon dioxide is released by water separation, thereby obtaining carbon dioxide as a high-purity gaseous phase. It was made clear that it could be used.

[0088] It has been shown that electrophoretic separation of dissolved and bound carbon dioxide, or carbonate anions / bicarbonate anions, in an aqueous acceptor medium can be achieved using electrodialysis equipment available in the prior art.

[0089] It has been further revealed that open-pore membranes are suitable for enabling the electrophoretic passage of dissolved carbon dioxide or carbonate / bicarbonate anions. In this method, dissolved carbon dioxide or carbonate / bicarbonate anions are transported electrophoretically toward the anode. When a DC voltage is applied to the electrode, the anions move toward the anode, and the anions can pass through a positively charged anion exchange membrane.

[0090] The following experimental configuration using an electrodialysis unit has been found to be particularly suitable for obtaining gaseous carbon dioxide in its purest form: cathode chamber / chamber for receiving acceptor solution (hereinafter referred to as the acceptor chamber) / chamber in which carbon dioxide is released in gaseous form (hereinafter referred to as the intake and release chamber) / anode chamber.

[0091] To achieve electrophoretic separation of dissolved carbon dioxide and its derivatives from an acceptor solution, the acceptor chamber is connected at the anode side to an incorporation and release chamber by a conductive medium, where the transported compound is preferably taken in and / or released or reacted. The medium present in the incorporation and release chamber is preferably an aqueous solution and is hereafter referred to as the incorporation and / or release medium.

[0092] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transport the bound carbon dioxide / carbon dioxide derivative in the acceptor solution from step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution from step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and Here, the transport of carbon dioxide / derivative in step c) is achieved by an electrical gradient established between the acceptor chamber and the intake and release chambers. Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane.

[0093] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) The carbonate anion / bicarbonate anion from the acceptor solution in step b) Transporting to an aqueous intake and release medium by passing through a separation membrane. Includes, Here, the acceptor solution from step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and Here, the transport of the carbonate anion / bicarbonate anion in step c) is achieved by an electrical gradient established between the acceptor chamber and the intake and release chamber. Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane.

[0094] When tap water is used as the intake and release medium in the intake and release chamber in that configuration, the formation of carbon dioxide bubbles occurs within the intake and release chamber, on the membrane separating this chamber from the acceptor chamber. The formation of bubbles covering the membrane between the acceptor chamber and the intake and release chamber has been shown to be highly undesirable because the gas layer develops electrical insulation in these areas, thereby significantly reducing the efficiency of the method. Furthermore, the use of an aqueous medium containing an electrolyte is undesirable because a solid may form, for example, in the form of sodium carbonate and / or calcium carbonate. Electrolytes that produce substantially water-insoluble carbonates, such as calcium carbonate, are particularly undesirable.

[0095] Nevertheless, it is necessary for the uptake and release media to have high electrical conductivity for electrophoresis to be performed. Furthermore, the compounds that establish electrical conductivity in the uptake and release media should not be transported electrophoretically themselves in the applied DC electric field. Surprisingly, it has become clear that organic and inorganic acids are suitable for providing the above requirements.

[0096] Surprisingly, it has been revealed that water-soluble organic compounds having one or more acidic groups are particularly suitable for converting dissolved carbon dioxide / carbonate anions / bicarbonate anions. These water-soluble organic compounds enter a chamber containing an incorporation and / or emission medium through a separation membrane, converting the dissolved carbon dioxide / carbonate anions / bicarbonate anions into a gaseous state, or generating / releasing them. This is particularly advantageous if the organic compound is not transported in an electric field and / or cannot leave the chamber containing the incorporation and / or emission medium through the separation membrane due to its molecular size.

[0097] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative from the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the aqueous uptake and release medium includes an organic acid or an inorganic acid.

[0098] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Bringing a gas containing carbon dioxide into contact with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative from the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the aqueous uptake and release medium comprises an organic acid or an inorganic acid, and the pH is in the range of 1 to 7, more preferably 2 to 6, and more preferably 3 to 5.

[0099] Therefore, a more preferred embodiment of the present invention relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) bringing a gas containing carbon dioxide into contact with the acceptor solution from step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative from the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the aqueous uptake and release medium comprises an organic acid and preferably has a pH in the range of 1 to 7, more preferably 2 to 6, and more preferably 3 to 5. Preferably, the organic acid is a compound having at least one acid group and has an isoelectric point at a pH between 3 to 5, preferably 3.5 to 4.5. In a preferred embodiment, the organic acid is preferably selected from the group comprising or consisting of citric acid, tartaric acid, and ascorbic acid. In a particularly preferred embodiment, the organic acid is citric acid. In a particularly preferred embodiment, the aqueous uptake and release medium comprises citric acid.

[0100] In a more preferred embodiment, the aqueous uptake and release medium comprises an organic acid, where the organic acid is an acidic amino acid having a carboxylic acid group (COOH) in its side chain. More preferably as specified herein, the aqueous uptake and release medium comprises an organic acid, wherein the organic acid is an amino acid having an acidic group. More preferably as specified herein, the aqueous uptake and release medium comprises an organic acid, wherein the organic acid is selected from the group comprising aspartic acid and glutamic acid. More preferably as specified herein, the aqueous uptake and release medium comprises an organic acid, wherein the organic acid is selected from the group comprising citric acid, tartaric acid, and ascorbic acid. Particularly preferred is tartaric acid. More preferably as specified herein, the aqueous uptake and release medium comprises an inorganic acid, wherein the inorganic acid is selected from the group comprising sulfuric acid or diphosphate, which is preferred.

[0101] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transport the bound carbon dioxide / carbon dioxide derivative in the acceptor solution from step b) through a separation membrane to an aqueous uptake and release medium containing citric acid. Includes, Here, the acceptor solution in step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and Here, the transport of carbon dioxide / carbon dioxide derivative in step c) is carried out by an electrical gradient established between the acceptor chamber and the intake and release chamber. And it was achieved, Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane.

[0102] Amino acids having an acidic group have been shown to satisfy this condition particularly well and are therefore particularly preferred. Preferably, the pH of the uptake and / or release medium is self-regulated by the dissociation of dissolved amino acids. Amino acids do not exhibit electrophoretic mobility at their isoelectric points. Therefore, it is particularly advantageous if the water-dissolved amino acids are present at their isoelectric points in both the acceptor medium and the uptake and / or release medium. This has the particularly advantageous effect that the compound responsible for solubilization, on the one hand responsible for transport, and on the other hand responsible for the separation / release of carbon dioxide / bicarbonate anions, remain in each solution and are therefore not mixed or consumed. This demonstrates the possibility of electrophoretic separation of carbonate anions / bicarbonate anions and diffusion-induced transport of dissolved carbon dioxide via an open-pored mesoporous membrane, for example, in the form of a ceramic filter plate. In this case, the pH of the acceptor solution, as well as the uptake and release medium, does not change during electrophoresis, and the release of carbon dioxide is achieved in the uptake and release chamber, thereby eliminating voltage drops due to bubble formation and adhesion to the separation membrane during electrophoresis. In this respect, the uptake medium according to the present invention satisfies the condition that the uptake and binding of carbon dioxide, or carbonate anions / bicarbonate anions, is achieved in the medium, and the uptake / bound carbon dioxide, or carbonate anions / bicarbonate anions, can be removed and transported away from the separation medium, and therefore the release of carbon dioxide can be carried out spatially away from the separation medium or the uptake and release chamber.

[0103] Preferably, the dissolution, electrophoretic transport, and separation / release of carbon dioxide / carbonate anions / bicarbonate anions are achieved by providing basic amino acids to an aqueous acceptor medium and by providing acidic amino acids to an aqueous incorporation and / or release medium at their isoelectric points.

[0104] Preferably, a gas or gaseous compound, and its derivatives, are bound in an aqueous acceptor medium, and by electrophoresis, the gas / gasic compound, or its derivatives in water are transported through a separation medium (separation membrane) and thereby enter an incorporation and release medium.

[0105] Preferably, a gas or gaseous compound, and derivatives thereof, are bound in an aqueous acceptor medium, and by electrophoresis, the gas / gasic compound, or derivative thereof, is transported through a separation medium in water and thereby enters an incorporation and release medium, wherein the gas or gaseous compound, and derivatives thereof, are released / generated as a gas phase and / or chemically react.

[0106] Preferably, the release of carbon dioxide / derivatives transported through a separation medium (separation membrane) is achieved in the form of pure carbon dioxide gas within the intake and release chamber.

[0107] Preferred basic amino acids are arginine and lysine. Preferred amino acids with an acidic group are aspartic acid and glutamic acid. When an acid with pKs > 3 is used as the uptake and release medium, the carbon dioxide, or carbonate anions / bicarbonate anions, transported electrophoretically therein are not released / generated as gaseous carbon dioxide in the membrane or within the uptake-release chamber. It was revealed that, or only a small amount, is already released / generated. In this case, it was revealed that the complete release of dissolved / bound carbon dioxide, or carbonate anions / bicarbonate anions, in the uptake and release medium can be achieved outside the uptake and release chamber, preferably on a hydrophobic surface in the collection container, by passing the uptake and release medium through it.

[0108] A high overflow rate in the separation medium (separation membrane) having the intake and release medium in the intake and release chamber is established, in particular by using a honeycomb-like spacer that causes turbulence in the intake and release chamber. This has been shown that when the intake and release medium is transmitted to a release device that contacts a surface where carbon dioxide release / generation is achieved, or a surface where carbon dioxide release / generation is brought about by the application of negative pressure, the release of carbon dioxide as a gas is achieved substantially only in the release device and not at all, or only in very small amounts, in the intake and release chamber. Therefore, in a preferred method embodiment, the release of carbon dioxide as a gas from the intake and release medium is carried out in a release device into which the intake and release medium is introduced from the intake and release chamber (see Figure 1). Preferably, the release device provides an interface for carbon dioxide release / generation. A hydrophobic interface is preferred.

[0109] Suitable devices for increasing the interfacial area include, for example, column packing materials. Preferably, carbon dioxide / carbonate anions / bicarbonate anions are taken into an intake and release medium in an intake and release chamber, the intake and release medium is then introduced into a release device, and carbon dioxide is released as a gas into the release device.

[0110] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transport the bound carbon dioxide / carbon dioxide derivative in the acceptor solution from step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution in step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and The transport of carbon dioxide / derivative in step c) is achieved by an electrical gradient established between the acceptor chamber and the intake and release chambers. Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane; Here, the method includes the following step c3) after step c): c3) In the release chamber, release carbon dioxide as a gaseous phase from the intake and release medium containing the bound carbon dioxide / derivative from step c).

[0111] In a preferred embodiment, carbon dioxide as the gaseous phase is released by applying a DC voltage to the intake and release medium from step c3).

[0112] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Bringing a gas containing carbon dioxide into contact with the acceptor solution in step a); and c) Transport the bound carbon dioxide / carbon dioxide derivative in the acceptor solution from step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution in step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and Here, the transport of carbon dioxide / derivative in step c) is achieved by an electrical gradient established between the acceptor chamber and the intake and release chambers. Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane; Here, the method includes the following step c3') after step c): c3') Introduce the aqueous uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c) into the release device.

[0113] In a preferred embodiment, the method includes the following step c3) after step c3'): c3) In the release device, release carbon dioxide as a gaseous phase from the intake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c3').

[0114] Therefore, preferred embodiments of the present invention relate to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transport the bound carbon dioxide / carbon dioxide derivative in the acceptor solution from step b) through a separation membrane to an aqueous uptake and release medium. Includes, Here, the acceptor solution in step b) is located in the acceptor chamber of the electrodialysis machine, or is introduced into the acceptor chamber of the electrodialysis machine; and The transport of carbon dioxide / derivative in step c) is achieved by an electrical gradient established between the acceptor chamber and the intake and release chambers. Here, the acceptor chamber and the intake and release chambers are separated from each other by a separation membrane; Here, the method relating to step c) includes the following steps c3') and c3): c3') Introducing an aqueous uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c) into the release device; and c3) In the release device, release carbon dioxide as a gaseous phase from the intake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c3').

[0115] It has been further revealed that the gas generated / released in the release chamber / release device or from the intake and release medium consists solely of carbon dioxide, or almost entirely of carbon dioxide. When an embodiment of the method according to the present invention is performed with the release of carbon dioxide as the gas phase in the release device, there is no increase in electrical resistance during the electrophoretic transport of carbon dioxide / carbonate anions / bicarbonate anions in the electrodialysis apparatus due to gas release / generation at the separation membrane, nor is there an increase in bubble formation in the intake and release chamber.

[0116] Preferably, this is a method for recovering and obtaining pure carbon dioxide gas. A pure gas contains impurities from other compounds in an amount of <0.5 vol%. In a more preferred embodiment of the method, an ionic liquid is used as the release medium. Ionic liquids are particularly advantageous because they are generally not water-soluble and do not undergo electrophoretic transport of the anions and cationic compounds that constitute them. Therefore, the application of an ionic liquid as a release medium in combination with an open-pore membrane separating the acceptor chamber from the intake and release chambers is a particularly preferred embodiment of the method.

[0117] Preferably, a gas or gaseous compound, and its derivatives thereof, are bound to an aqueous acceptor medium, and by an electrophoretic step, the gas / gasic compound, or its derivatives thereof in water are transported through a separation medium (separation membrane) and thereby enter an incorporation and release medium, where the incorporation and release medium is an ionic liquid.

[0118] Preferably, the gas or gaseous compound and its derivative are bound to an aqueous acceptor medium, and the gas / gasic compound or its derivative is transported in water through a separation medium (separation membrane) by an electrophoretic step, thereby entering an intake and release medium which is an ionic liquid, where the gas or gaseous compound and its derivative are chemically reacted.

[0119] In a particularly preferred embodiment, the separation of carbon dioxide from a gas / gas mixture is semi-continuous or continuous. Preferably for this purpose, the apparatus is such that dissolution / dissociation of carbon dioxide occurs in one of the aqueous acceptor solutions according to the present invention, and simultaneously, separation of dissolved carbon dioxide or carbonate anions / bicarbonate anions from the acceptor solution is achieved. Selective separation of bound carbon dioxide / carbonate anions / bicarbonate anions is preferably achieved by transport via a separation medium (separation membrane). The use of a membrane as the separation medium for the separation of dissolved carbon dioxide or carbonate anions / bicarbonate anions is preferred. Electrophoretic separation is preferred. For this purpose, the use of an electrodialysis unit is particularly preferred. In one embodiment, loading of a gas / gas mixture containing carbon dioxide is performed in a chamber containing an acceptor solution. The gas / gas mixture, with reduced carbon dioxide exiting this chamber, is then moved to the next chamber containing an acceptor solution. This arrangement can be repeated continuously multiple times. The gas can be loaded both in the chamber containing the acceptor solution in each dialysis cell and in the outer container, thereby establishing recirculation between the container in the dialysis unit and each chamber. Preferably, the gas / gas mixture in the acceptor medium is dispersed as finely as possible.

[0120] For this purpose, prior art can be used. The gas scrubbing column can be configured using this method arrangement so that a carbon dioxide-containing gas stream comes into contact with the acceptor medium several times in succession.

[0121] It has been demonstrated that after the separation of carbon dioxide / carbonate anion / bicarbonate anion from an acceptor medium saturated with carbon dioxide, the acceptor medium can be reused to dissolve, bind, and transport carbon dioxide. In a particularly advantageous method, this enables the recycling of the acceptor medium, so that carbon dioxide can be continuously or semi - continuously taken up, transported, and separated without loss, and the acceptor medium can be used repeatedly as required to repeat the process.

[0122] A preferred method is one in which, after the separation of carbon dioxide / carbonate anion / bicarbonate anion from the acceptor medium, the reuse of the acceptor medium for redissolving and binding carbon dioxide therein is carried out without loss.

[0123] The presence of deprotonated guanidino / amidino groups in the dissolved acceptor compound indicates that gaseous carbon dioxide can be completely solubilized and bound in an aqueous solution of a compound having a guanidino / amidino group. It is irrelevant what ratio carbon dioxide is present in relative to other gaseous compounds / elements or whether it is a pure carbon dioxide gas stream. Under this condition, depending on the contact time and the interface reached between the aqueous acceptor medium and the gas / gas mixture, complete (<1 ppm) or nearly complete (<= 100 ppm) removal of carbon dioxide from the gas / gas mixture is achieved.

[0124] Preferably, it is a method for removing carbon dioxide from a gas or gas mixture. Therefore, for the first time, a method can be provided that enables the complete or near-complete removal of carbon dioxide from a gas or gas mixture by contacting the gas or gas mixture with an aqueous acceptor medium at atmospheric pressure, and subsequently allows for the selective re-obtaining of gaseous carbon dioxide in a highly purified or pure form. In this context, highly purified means that the carbon dioxide content is >99.5 vol%, and pure means that the carbon dioxide content is >98.5 vol%.

[0125] In this regard, the method further addresses the selective separation, recovery, and generation of pure carbon dioxide. Preferably, the method is for the selective separation, recovery, and production of pure or highly purified carbon dioxide.

[0126] When a gas / gas mixture contains several gaseous compounds that form acids in water, these can be incorporated into the acceptor medium, and therefore, if only one of the gaseous compounds is recovered, it has been shown to affect the separation efficiency. This is particularly true in the case of gases produced during the fermentation of organic materials, so-called "acidic natural gas," and flue gas or digester gas. Furthermore, flue gas may contain solids that can lead to soot formation in the acceptor solution. In a preferred embodiment of the method, all solid particles / liquids and gaseous compounds that dissolve in an aqueous medium or form water-soluble reaction products therein are separated before contacting the gas / gas mixture with the acceptor medium. This can be done using prior art methods. Therefore, pre-purification of the gas stream to which carbon dioxide is bound or recovered is preferred.

[0127] Preferably, the method involves separating / adsorbing liquid and solid components that dissolve in water or form water-soluble reaction products upon contact with water, as well as gaseous components other than carbon dioxide, before contacting the gas / gas mixture containing carbon dioxide with the acceptor medium.

[0128] Therefore, a method can be provided for the adsorption, transport, and selective release of carbon dioxide, wherein the method is free of corrosive or health-harmful compounds, and the aqueous acceptor medium can be completely recycled after the separation of the carbon dioxide bound therein and used for further absorption of carbon dioxide.

[0129] Preferably, the method involves providing an aqueous acceptor medium for the absorption, transport, and selective release of carbon dioxide, without the use of corrosive or health-harmful compounds, and ensuring that the aqueous acceptor medium is completely recycled and, after the separation of the carbon dioxide bound therein, can be completely recycled and used for reabsorbing carbon dioxide.

[0130] Preferably, this method involves reversibly bonding a gaseous compound to an acceptor compound dissolved in water in an aqueous acceptor medium. Preferably, the gaseous compound present in the aqueous acceptor medium and the water-soluble acceptor compound This method achieves a reversible bond between substances via a reaction product between a gaseous compound and water.

[0131] Preferably, the reaction product between the gaseous compound and the aqueous phase in the aqueous acceptor medium is reversibly bonded by the dissolved acceptor compound. Preferably, the gaseous compound in the aqueous acceptor medium is bound by the acceptor compound, and the bound gaseous compound can be released again as a gas by a change in pH in the acceptor solution, by substitution of the gaseous compound by the addition of an anionic compound, or by electrophoretic separation.

[0132] Preferably, the method includes binding a gaseous compound in an aqueous acceptor medium, subsequently releasing the gaseous compound, regenerating the acceptor compound, and then providing an acceptor medium for rebinding the gaseous compound.

[0133] Further method embodiments have been revealed to be achievable by the methods of the present invention for the absorption, transport, and selective release of carbon dioxide. It was revealed that hydrogen is released during the process of dissolving carbon dioxide in an aqueous acceptor medium. Between 0.5 moles and 2 moles of hydrogen can be produced for each mole of carbon dioxide bound to the acceptor medium. The hydrogen enters the gas / gas mixture as a gas and is released after contact with the acceptor medium. Hydrogen is a high-demand raw material; therefore, in a preferred embodiment of the method, the amount of hydrogen obtainable in the method embodiment according to the present invention is recovered. In a preferred embodiment of the method, the hydrogen produced during the process embodiment is adsorbed. Methods and apparatus for hydrogen adsorption and separation are known in the prior art. For example, the gas / gas mixture collected after contact with the acceptor medium can be passed through a medium suitable for binding and / or separating hydrogen therein, and recovered and / or reacted directly or in a secondary circuit. In this regard, the method further addresses the generation and recovery of hydrogen.

[0134] Preferably, the method involves generating hydrogen by contacting a gas / gas mixture containing carbon dioxide with an acceptor medium, and then adsorbing and / or separating and recovering the generated hydrogen. Preferably, the method is for generating and recovering hydrogen, in which the gas / gas mixture is contacted with an acceptor medium. Preferably, the acceptor medium is for generating and recovering hydrogen.

[0135] Surprisingly, it was revealed that carbon dioxide is incorporated into the aqueous acceptor medium by the presence or addition of a cationic compound to the aqueous acceptor medium according to the present invention, or that carbon dioxide is already bound, resulting in the spontaneous formation of a carbonate. It was also revealed that a solid is formed when the aqueous acceptor medium comes into contact with a gas containing a water-soluble gaseous compound in the presence of sodium ions or calcium ions. When the water-soluble gaseous compound is carbon dioxide, it was revealed that sodium carbonate or calcium carbonate is formed.

[0136] Preferably, the method involves binding a gaseous compound in an acceptor medium and bringing it into contact with one or more compounds, where a physicochemical or chemical reaction is achieved between the gaseous compound bound to the acceptor compound, or between the anionic form of the gaseous compound and at least one other compound.

[0137] Preferably, the gaseous compound in the acceptor medium is bound by an acceptor compound that enables and / or catalyzes a reaction between the bound gaseous compound or the anionic form of the gaseous compound and one or more other compounds.

[0138] Next, it was revealed that alkali metal and alkaline earth metal salts dissolve very readily in the aqueous acceptor medium according to the present invention. Surprisingly, compared to the dissolution process in water, no reaction occurred, or only a very small exothermic reaction occurred. This is especially true for the dissolution of calcium, iron, and aluminum salts, such as calcium chloride, iron chloride, or aluminum chloride. Surprisingly, this presents even more particularly advantageous opportunities in the formation of carbonates and bicarbonates.

[0139] When the acceptor solution according to the present invention is introduced into an acceptor solution saturated with carbon dioxide, for example, in which aluminum chloride or iron chloride is dissolved, very fine white or light brown solid particles are formed, which exist as a suspension under stirring and settle after stirring is stopped. It is possible to demonstrate that the solid was aluminum carbonate or iron carbonate. Surprisingly, when the acceptor solution containing the dissolved salt is mixed into an acceptor solution saturated with carbon dioxide, there was no or minimal release of gaseous carbon dioxide under atmospheric conditions. Therefore, a method can be provided to enable nearly complete or complete chemical conversion of carbon dioxide / carbonate anions / bicarbonate anions bound to an acceptor medium under atmospheric pressure and room temperature conditions.

[0140] Therefore, in a highly advantageous manner, compounds (reacting compounds) that undergo chemical transformation using carbon dioxide and / or carbonate anions and / or bicarbonate anions dissolve completely in an acceptor medium containing at least one acceptor compound and readily and rapidly come into contact with carbon dioxide / carbonate anions / bicarbonate anions without causing an exothermic reaction in an aqueous medium and without the release of carbon dioxide. These beneficial effects have been shown to occur even when the reacting compounds are provided in the same manner in the incorporation and release medium or in the reacting medium for chemical transformation.

[0141] Preferably, the method involves dissolving at least one reaction compound together with an acceptor compound, and then contacting the dissolved reaction compound with carbon dioxide and / or carbonate anions and / or bicarbonate anions to chemically react with the carbon dioxide and / or carbonate anions and / or bicarbonate anions.

[0142] The study further clarifies that when an acceptor solution containing a cationic compound capable of forming carbonates and / or bicarbonates is brought into contact with a gas / gas mixture containing carbon dioxide, carbonates and / or bicarbonates, carbonates and / or bicarbonates are formed and precipitate during the gas application process.

[0143] Preferably, this method involves binding the gaseous compound to an acceptor compound dissolved in water as a reaction product, and then contacting these products with other compounds in this form, thereby allowing the gaseous compound to be chemically reacted in an aqueous acceptor medium.

[0144] Preferably, the method involves at least one water-soluble inorganic or organic compound being dissolved or solubilized by an acceptor compound dissolved in an aqueous acceptor medium, so that at least one compound is partially or completely dissolved in the acceptor medium, and the acceptor medium coming into contact with at least one gaseous compound simultaneously with or following the dissolution of at least one compound, thereby bringing about a physicochemical or chemical reaction between the at least one gaseous compound dissolved in the acceptor medium and the at least one compound.

[0145] In a more preferred embodiment of the method, cationic compounds that can form carbonates or bicarbonates are introduced into an acceptor solution by electrophoresis. This is carried out by selective introduction. Preferably, this is done in a method configuration in which an electrolyte solution containing a cation / cationic compound suitable for the formation of a carbonate or bicarbonate is introduced into an electrodialysis chamber within an electrodialysis apparatus, and instead of intake and release chambers, the electrolyte chamber is connected to one of the acceptor chambers containing the acceptor solution, and a cation-selective membrane is placed between the electrolyte chamber and the acceptor chamber so that the chambers are electrically coupled to each other. Electrophoretic transport of the cation / cationic compound from the electrolyte chamber to the acceptor chamber is achieved by applying a DC voltage between the anode chamber and the cathode chamber. Optionally, the acceptor chamber may contain an acceptor solution that is already saturated with carbon dioxide or is continuously filled with carbon dioxide during the dialysis process. As will be disclosed in more detail below, the chemical conversion of carbon dioxide and / or carbonate and / or bicarbonate is also possible using other compounds. Compounds that react with or can react with carbon dioxide and / or carbonates and / or bicarbonates while present in or transported into an acceptor medium, or whose conversion is achieved outside the acceptor medium using carbon dioxide and / or carbonate anions and / or bicarbonate anions dissolved and transported by the acceptor medium, are hereafter referred to as reacting compounds.

[0146] Therefore, it was possible to establish a conversion method that allows the reaction compound to be brought into contact with a carbonate anion / bicarbonate anion and to chemically react with each other. As further described below, the reaction method can be designed in various embodiments and can be carried out using various reaction compounds.

[0147] It was further revealed that, due to the improved solubility resulting from the basicity of the acceptor medium, solutions containing significantly higher concentrations of salts of the reacting compounds (but also non-salt compounds) than possible in pure water can be prepared. In experiments where acceptor solutions containing dissolved sodium, calcium, or aluminum salts were gas-treated with pure carbon dioxide or a mixture of carbon dioxide-containing gases, it was found that a milky suspension formed very rapidly. The resulting solid settled spontaneously, and thus complete phase separation could be achieved by a sedimentation phase or zone without stirring. However, phase separation could also be achieved by centrifugation or filtration.

[0148] The carbonate or bicarbonate produced by this method is chemically pure and readily available in the form of very small particles <1 μm, or can be dispersed into very small particles with little energy input.

[0149] The retention of anions of dissolved salts in the acceptor solution, such as chloride ions, has been found to be a drawback. It has been found that binding or separating salt anions dissolved in the acceptor solution is possible by various prior art methods. In one embodiment, the separation of salt anions is performed by electrodialysis after introducing the salt or a salt solution into an aqueous acceptor medium, or after contacting the aqueous acceptor medium with a gas / gas mixture containing carbon dioxide.

[0150] Preferably, the acceptor compound present in the acceptor medium is regenerated by electrodialysis or contact with an ion exchange compound or adsorbent, after the acceptor medium of anionic compounds excluding the hydroxide anion is purified following the binding of a gaseous compound or the anionic form of a gaseous compound.

[0151] Therefore, the method also covers the production of chemically pure carbonates and bicarbonates, which are available in powder form. Preferably, the carbonates and bicarbonates exist in amorphous form. .

[0152] Preferably, this method allows for obtaining carbonates and / or bicarbonates in a chemically pure form by dissolving carbon dioxide or carbonate anions / bicarbonate anions using an aqueous acceptor medium containing dissolved guanidino and / or amidino group-containing compounds, and then contacting them with a dissolved cationic / cationic compound capable of binding them and forming carbonates or bicarbonates.

[0153] Preferably, this method involves dissolving a cationic / cationic compound capable of forming a carbonate or bicarbonate in an aqueous acceptor medium containing a dissolved guanidino group and / or amidino group compound, and then contacting them with carbon dioxide and each carbonate anion / bicarbonate anion to obtain carbonates and bicarbonates in a chemically pure form.

[0154] Preferably, this is a method for preparing carbonates and bicarbonates. The present invention reveals that these carbonates and bicarbonates can be produced by the absorption and dissolution of carbon dioxide released from a recycled raw material source, for example, through fermentation into biogas or combustion of wood. For example, it is currently possible to produce recycled carbonates and bicarbonates under the condition that recycled cations / cationic compounds and recycled energy, which can be obtained by one of the methods for the regeneration of organic and inorganic compounds, are used in the execution of the method.

[0155] Preferably, it is a method for producing regenerated carbonate and regenerated bicarbonate. Preferably, these are regenerated carbonates and regenerated bicarbonates. Therefore, in another embodiment of the present invention, the method further relates to providing carbon dioxide, or carbonate anions / bicarbonate anions, in high concentrations in an aqueous acceptor medium and chemically reacting them therewith with other compounds.

[0156] Preferably, the method involves providing carbon dioxide, or carbonate anion / bicarbonate anion, in a high concentration in an aqueous acceptor medium and chemically reacting it therewith with other compounds.

[0157] Therefore, the method further relates to transformation methods that can obtain reaction products by transforming organic and / or inorganic compounds using dissolved or dissolved and transported gases / gaseous compounds and / or derivatives thereof.

[0158] Preferably, the conversion method involves contacting and reacting organic and / or inorganic compounds with dissolved, or dissolved and transported, gases / gaseous compounds and / or derivatives thereof.

[0159] Preferably, the reaction product can be obtained by converting organic and / or inorganic compounds using dissolved, or dissolved and transported, gases / gaseous compounds and / or derivatives thereof.

[0160] Preferably, the method is for the selective binding, transport, reaction activation, conversion, and / or release of carbon dioxide. Therefore, the problem is solved by dissolving carbon dioxide in an aqueous medium containing dissolved guanidino and / or amidino group-containing compounds, storing and / or transporting it therein, and / or reacting it therein, and / or releasing it therefrom. ru.

[0161] As described above, surprisingly, the solubility of carbon dioxide in aqueous media was significantly increased compared to pure water by compounds containing free guanidino and / or amidino groups dissolved in the aqueous media, revealing that carbon dioxide remained bound in aqueous solutions. Even more surprising was the observation that the solubility of compounds containing guanidino and / or amidino groups could increase as the amount of bound carbon dioxide increased. For example, in the case of arginine, the solubility limit in water is 0.6 mol / l at 20°C (or, depending on the raw material, approximately 150 g / l at 20°C, and 150 g ≈ 0.86 mol, M(arginine) = 174.20 g / mol), and it was revealed that when carbon dioxide was introduced simultaneously, an amount exceeding 3 mol / l (522.6 g / l) dissolved or dissolved into the solution. The aqueous media remained clear, and the pH was between 10 and 12.5. It has been shown that carbon dioxide, or its reaction products in water, such as carbonate anions and bicarbonate anions, can be dissolved without pressure (at atmospheric pressure or normal pressure) in an aqueous solution containing a dissolved guanidino group and / or amidino group compound, where they can be bonded in a molar ratio of > / = 1:1. Therefore, carbon dioxide or carbonate anions / bicarbonate anions, respectively, can be bonded without pressure (at atmospheric pressure or normal pressure) by a compound having free guanidino groups and / or amidino groups dissolved in an aqueous medium without pressure (at atmospheric pressure or normal pressure), preferably at concentrations of >0.5 mol / l, more preferably >1.0 mol / l, more preferably >1.5 mol / l, more preferably >2.0 mol / l, more preferably >2.5 mol / l, more preferably >3.0 mol / l, and even more preferably >3.5 mol / l, as described herein.

[0162] In a preferred embodiment, the provision of an aqueous solution for carbon dioxide uptake, transport, conversion, release and / or storage is in the form of an acceptor solution. Preferably, the acceptor solution is provided in an acceptor chamber or acceptor device.

[0163] The acceptor apparatus includes a device suitable for establishing the largest possible exchange area between the gas / gas mixture and the acceptor medium, and / or for bringing the gas / gas mixture into contact with the acceptor medium. For this purpose, prior art methods are known.

[0164] A gas scrubbing apparatus (see also Figure 1) or gas scrubbing column represents one form. Therefore, a method is preferred that includes the step of bringing a gas containing carbon dioxide into contact with the acceptor solution from step a) in a gas scrubbing apparatus or gas scrubbing column.

[0165] In the case of gaseous mixtures containing non-gaseous components, it is preferable to first remove the gaseous components from the non-gaseous mixture, for example, by filtration or washing the gas with another liquid. Methods for separating non-gaseous components are known to those skilled in the art from the prior art. In a preferred embodiment, the gas containing carbon dioxide is filtered and / or washed before contact with the acceptor solution according to the present invention in order to remove non-gaseous components. For example, undesirable gases such as H2S and NH3 or acidic gases other than SO2 and carbon dioxide can be washed away from the gas containing carbon dioxide in an upstream gas washing column to remove them.

[0166] Preferably, the gas mixture is further subjected to initial scrubbing with an acidic solution. Surprisingly, it has been shown that the carbon dioxide concentration of the gas / gas mixture can be reduced much more rapidly by contacting it with an acid-containing solution than by contacting it with an acid-containing solution, compared to when the gas mixture is not pre-activated before subsequent contact with an acceptor solution.

[0167] The present invention preferably involves selectively binding and transporting carbon dioxide in an aqueous medium, and Regarding how to store it, follow these steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or Store and / or transport the acceptor solution containing carbon dioxide / carbon dioxide derivative from step b). Includes, Here, the gas containing carbon dioxide is washed with an acidic solution before step b).

[0168] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Store and / or transport the acceptor solution containing carbon dioxide / carbon dioxide derivative from step b); and / or Step b) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution through a separation membrane to an aqueous uptake and release medium. Includes, Here, the gas containing carbon dioxide is washed with an acidic solution before step b).

[0169] Preferably, the activation of the gas mixture is brought about by contact with an acidic solution, thereby improving the solubility of carbon dioxide in the acceptor medium. In a preferred embodiment, the gas containing carbon dioxide is washed with an acidic solution before contact with the acceptor solution according to the present invention. In principle, any acid or acid-forming compound can be used for this purpose. Preferred acids are HCl (hydrochloric acid), sulfuric acid, or phosphoric acid. In a preferred embodiment, the gas containing carbon dioxide is washed with an acidic solution selected from hydrochloric acid, sulfuric acid, or phosphoric acid before contact with the acceptor solution according to the present invention.

[0170] In addition to the methods already described above for directly contacting an aqueous acceptor medium with a gas / gas mixture, methods have been studied for indirectly contacting a gaseous medium with a liquid medium. It has been shown that carbon dioxide, or its water-soluble derivative, can pass through a solid or semi-solid separation medium (gas / liquid separation membrane) that separates the gaseous phase containing carbon dioxide from the aqueous acceptor solution, thereby providing highly efficient and selective transport of carbon dioxide or its derivative to the aqueous acceptor medium. In preferred embodiments, the indirect contact between the gaseous phase and the liquid phase is achieved by a membrane contactor.

[0171] Preferably, the method includes the step of bringing a gas containing carbon dioxide into contact with the acceptor solution from step a) using a membrane contactor. In a membrane contactor, phases in contact with each other are separated by a membrane. In a preferred embodiment, contact between an aqueous acceptor medium and a gas / gas mixture is carried out by a membrane contactor. Surprisingly, when an open-pore membrane is used in the membrane contactor, the membrane contactor allows for very high diffusion of water-soluble gases or gaseous compounds from the gas phase to the liquid phase. We demonstrated that this enables high speeds. We revealed that the high diffusion / transport rates for gaseous water-soluble compounds are due to the properties of the acceptor medium. For example, the aqueous acceptor solution has a surface tension no different from water compared to prior art aqueous absorbents such as solutions of alkanolamines. In contrast, the surface tension decreases for absorbent compounds exhibiting surfactant or alcohol properties. Therefore, open-pore membranes are not applicable when using aqueous solutions with prior art absorbent compounds because of liquid leakage. We demonstrated that there is no leakage of the acceptor solution through / out of an open-pore membrane with an average pore size of 200 μm under atmospheric pressure conditions, either on the gas side or the liquid side. We demonstrated that complete extraction of carbon dioxide can be achieved in a membrane contactor with much smaller spatial dimensions than a gas scrubbing apparatus with packing by using the constructibility of the membrane contactor.

[0172] For example, a flat membrane module can be provided that has very flat channels for both the gaseous and liquid phases, while simultaneously having a relatively short channel length. This allows for the design of membrane contacts that can be optimally adapted to individual gas / gas compositions and volumetric flow rates from a flow technology perspective. Various designs are known in the prior art, such as wound modules, hollow fiber modules, or tube modules.

[0173] The preferred membrane / solid separation medium for the step of contacting a gas containing carbon dioxide with an acceptor solution according to the present invention has a low build-up height (membrane thickness). This is preferably <300 μm, more preferably <200 μm, more preferably <150 μm, more preferably <100 μm, more preferably <50 μm, and even more preferably <25 μm. Therefore, the method preferably includes the step of contacting a gas containing carbon dioxide with the acceptor solution in step a) using a gas-liquid separation membrane having an average pore size of 200 μm at atmospheric pressure. Therefore, the method preferably includes the step of contacting a gas containing carbon dioxide with the acceptor solution in step a) using a membrane having a film thickness of <300 μm, more preferably <200 μm, more preferably <150 μm, more preferably <100 μm, more preferably <50 μm, and even more preferably <25 μm. Therefore, preferably, the method includes the step of contacting a gas containing carbon dioxide with the acceptor solution in step a) at atmospheric pressure using a membrane having an average pore size of 200 μm, where the membrane has a film thickness of <300 μm, more preferably <200 μm, even more preferably <150 μm, more preferably <100 μm, even more preferably <50 μm, and even more preferably <25 μm. Therefore, preferably, the method includes the step of contacting a gas containing carbon dioxide with the acceptor solution in step a) using a membrane having an average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm.Therefore, the method preferably comprises the step of bringing a gas containing carbon dioxide into contact with the acceptor solution in step a) at atmospheric pressure using a membrane having an average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm, where the membrane has a film thickness of <300 μm, more preferably <200 μm, even more preferably <150 μm, more preferably <100 μm, even more preferably <50 μm, and even more preferably <25 μm. Therefore, the method preferably comprises the step of bringing a gas containing carbon dioxide into contact with the acceptor solution in step a) using a membrane having an average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm, where the membrane has a thickness of <300 μm, more preferably <200 μm, even more preferably <150 μm, more preferably <100 μm, even more preferably <50 μm, and even more preferably <25 μm. It has a film thickness of μm.

[0174] In this context, the membrane / foil may be attached to or bonded to a support material. Preferably, the membrane / solid separation medium is open-pore, i.e., exhibits a continuous channel or channel-like structure with both sides of the membrane / solid separation medium open. In the prior art, average channel diameter or average pore size has been reported. Preferred membrane / solid separation mediums have open channels having an average channel diameter or average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm.

[0175] Preferably, the membrane / solid separation medium has a high porosity (number of pores per unit area). Preferably, the membrane / solid separation medium has a porosity of >50%, more preferably >60%, more preferably >70%, more preferably >80%, and even more preferably >90%. In principle, any material that can be used to manufacture prior art membrane / solid separation mediums is suitable for the method according to the present invention. It is preferable to select according to the individual application. For example, in applications where high-temperature gases / gas mixtures (e.g., >130°C) are in contact with the membrane, it is preferable to select a heat-resistant material. Suitable materials in this regard include PTFE (polytetrafluoroethylene), PC (polycarbonate), or ceramic membranes. Therefore, the method preferably comprises the step of contacting a gas containing carbon dioxide with an acceptor solution from step a) using a film having an average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm, wherein the film has a thickness of <300 μm, more preferably <200 μm, more preferably <150 μm, more preferably <100 μm, more preferably <50 μm, and even more preferably <25 μm, wherein the film is selected from a polytetrafluoroethylene (PTFE) film, a polycarbonate (PC) film, or a ceramic film.

[0176] Particularly suitable materials for creating the membrane / solid separation medium can be selected for different applications. For example, in a preferred embodiment, to remove carbon dioxide content from the air, air is used as the gas phase, and a membrane having hydrophobic surface properties measurable by a water contact angle >90° is preferably used. Preferably, this membrane further exhibits lipophilic surface properties measurable by a contact angle with, for example, oleic acid <10°. In a more preferred embodiment, air is used as the gas phase, the membrane / solid separation medium according to the present invention is used, and a hydrophilic surface coating is further provided. Preferably, the hydrophilic surface coating simultaneously exhibits hygroscopic properties.

[0177] It has been shown that the membrane contactor can also be used to remove gases / gaseous components other than carbon dioxide from a gas / gas mixture, provided that the membrane contactor is water-soluble and is absorbed by the acceptor medium according to the present invention.

[0178] In a preferred method embodiment, a high overflow rate in the liquid phase and / or gas phase is set for the membrane / solid separation medium of the membrane contactor in the membrane contactor.

[0179] The acceptor solution contains at least one acceptor compound that is readily soluble in water. This acceptor compound may be completely dissolved or may be incompletely dissolved. Preferably, the dissolution and mixing of carbon dioxide with / along with carbon dioxide in the acceptor solution is achieved during the passage / contact of the gas / gas mixture through / using the acceptor solution.

[0180] At least one dissolved / soluble compound in the acceptor solution preferably makes the solution basic in pH. The pH of the acceptor solution is preferably between 7 and 14, more preferably between 8 and 13, and even more preferably between 9 and 12.5. In other words, when the acceptor compound is dissolved, a pH between 7 and 14, more preferably between 8 and 13, and even more preferably between 9 and 12.5 is established.

[0181] Preferred water-soluble acceptor compounds have at least one guanidino group and / or amidino group. Preferred acceptor compounds have a guanidino group and / or amidino group, and more preferably, are acceptor compounds having a free guanidino group and / or amidino group. In some embodiments, acceptor compounds having an amidino group are preferred, and more preferably, are acceptor compounds having a free amidino group.

[0182] In some embodiments, acceptor compounds having a guanidino group are preferred, and more preferably, acceptor compounds having a free guanidino group. Water-soluble compounds having a free guanidino group are particularly preferred.

[0183] A particularly preferred compound having a guanidino group is the amino acid arginine. The preferred concentration of the acceptor compound in the acceptor solution is between 10 μmol and 10 mol / l, more preferably between 10 mmol / l and 5 mol / l, and even more preferably between 0.1 mol / l and 3 mol / l. It should be noted that the solubility of the acceptor compound can be increased by the binding of carbon dioxide. Therefore, the acceptor compound can be added while bringing a gas containing carbon dioxide into contact with the acceptor solution.

[0184] The temperature at which the acceptor solution is brought into contact with the gas / gas phase can, in principle, be in the range of 0°C to 100°C. The preferred temperature at which contact between the gas / gas mixture and the acceptor solution occurs is between 1°C and 60°C, more preferably between 10°C and 35°C, and even more preferably between 15°C and 30°C.

[0185] Remarkably, the acceptor solution is particularly suitable for the unpressurized (atmospheric or normal pressure) storage of dissolved carbon dioxide. Acceptor solutions containing dissolved and bound carbon dioxide remain stable for 12 months, notably showing no carbon dioxide release / generation or microbial colonization of the medium. Remarkably, even high concentrations of arginine, such as 3 mol / l, do not crystallize or form precipitates, even when stored at a temperature of 3°C.

[0186] The aqueous acceptor solution according to the present invention is preferably a solution of one, two, or more amino acids and / or peptides, which are present at individual and / or total concentrations in the range of 10 mmol / l to 15 mol / l, more preferably between 100 mmol / l and 10 mol / l, and even more preferably between 0.1 mol / l and 5 mol / l. These may be L-form, D-form, or racemic compounds. Preferred amino acids are arginine, and more preferably their derivatives. Particularly preferred are basic amino acids and peptides having a cationic group (a positively charged functional group). Peptides that can be used according to the present invention may be di-, tri-, and / or polypeptides. Peptides according to the present invention have at least one functional group that binds or can bind a proton. Therefore, preferred molecular weights are less than 500 kDa, more preferably <250 kDa, even more preferably <100 kDa, and particularly preferably <1000 Da. Therefore, preferred functional groups are, in particular, guanidine, amidine, amine, amide, hydrazine, hydrazone, hydroxyimine, or nitro groups. Thus, an amino acid may have a single functional group, or it may contain one or more functional groups from several of the same or different compound classes.

[0187] Preferably, the amino acids and peptides according to the present invention have at least one positively charged group (cationic group / positively charged functional group), or are positively charged overall.

[0188] Particularly preferred peptides include at least one of the amino acids arginine, lysine, and histidine in any number and order. Particularly preferred are amino acids and / or amino acid derivatives having at least one guanidino group and / or amidino group. However, other acceptor compounds having at least one guanidino group and / or amidino group are even more preferred. The guanidino group is the chemical residue H2N-C(NH)-NH- and its cyclic form, and the amidino group is the chemical residue H2N-C(NH)- and its cyclic form. These guanidino and amidino compounds preferably have a partition coefficient K between n-octanol and water. OW is less than 6.3 (K OW It has <6.3).

[0189] Arginine derivatives are particularly preferred. Arginine derivatives are defined as compounds having a guanidino group and a carboxylate group, or an amidino group and a carboxylate group, where the guanidino group and the carboxylate group, or the amidino group and the carboxylate group, are separated by at least one carbon atom, i.e., at least one of the following groups is located between the guanidino group or the amidino group and the carboxylate group: -CH2-, -CHR-, -CRR'-, where R and R' independently represent any chemical residue. Of course, the distance between the guanidino group and the carboxylate group, or between the amidino group and the carboxylate group, may be more than one carbon atom, for example, when the following groups are present: -(CH2)n-, -(CHR)n-, -(CRR')n-, n=2, 3, 4, 5, 6, 7, 8, or 9, as in the case of amidinopropionic acid, amidinobutyric acid, guanidinopropionic acid, or guanidinobutyric acid. Compounds having more than one guanidino group and more than one carboxylate group include oligoarginines and polyarginines. Other examples of compounds that fit this definition are guanidinoacetic acid, creatine, and glycocyamines.

[0190] Preferred compounds share the common characteristic of general formula (I) or (II).

[0191] [Chemical]

[0192] In the formula, R, R’, R’’, R’’’, and R’’’’ are, independently of one another, -H, -CH=CH2, -CH2-CH=CH2, -C(CH3)=CH2, -CH=CH-CH3, -C2H4-CH=CH2, -CH3, -C2H5, -C3H7, -CH(CH3)2, -C4H9, -CH2-CH(CH3)2, -CH(CH3)-C2H5, -C(CH3)3, -C5H 11 , -CH(CH3)-C3H7, -CH2-CH(CH3)-C2H5, -CH(CH3)-CH(CH3)2, -C(CH3)2-C2H5, -CH2-C(CH3)3, -CH(C2H5)2, -C2H4-CH(CH3)2, -C6H 13 , - C7H 15 , cyclo-C3H5, cyclo-C4H7, cyclo-C5H9, cyclo-C6H 11 , -C≡CH, -C≡C-CH3, -CH2-C≡CH, -C2H4-C≡CH, -CH2-C≡C-CH3, representing or both R’ and R’’ form a residue -CH2-CH2-, -CO-CH2-, -CH2-CO-, -CH=CH-, -CO-CH=CH-, -CH=CH-CO-, -CO-CH2-CH2-, -CH2-CH2-CO-, -CH2-CO-CH2-, or -CH2-CH2-CH2-; X represents -NH-, -NR’’’’, or -CH2-, or a substituted carbon atom; and L is -NH2, -OH, -PO3H2-, -PO3H - , -PO3 2- , -OPO3H2, -OPO3H - , -OPO3 2- , -COOH, -COO-, -CO-NH2, -NH3 + , -NH-CO-NH2, -N(CH3)3 + , -N(C2H5)3 + , -N(C3H7)3 + , -NH(CH3)2 +, -NH(C2H5)2 + , -NH(C3H7)2 + , -NHCH3, -NHC2H5, -NHC3H7, -NH2CH3 + , -NH2C2H5 + , -NH2C3H7 + , -SO3H, -SO3 - , -SO2NH2, -C(NH)-NH2, -NH-C(NH)-NH2, -NH-COOH, or

[0193]

Chem.

[0194] The carbon chain L preferably ranges from C1 to C7, more preferably from C1 to C6, still more preferably from C1 to C5, and most preferably from C1 to C4.

[0195] Preferably, L represents -CH(NH2)-COOH, -CH2-CH(NH2)-COOH, -CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, or -CH2-CH2-CH2-CH2-CH2-CH(NH2)-COOH.

[0196] Preferably, as shown below, it is a compound of general formula (III) having a free guanidino group and / or an amidino group:

[0197]

Chem.

[0198] In the formula, the residues X and L have the meanings disclosed herein.

[0199] Preferred compounds having free guanidino groups and / or amidino groups share common characteristics. The general formula (III) is:

[0200] [ka]

[0201] During the ceremony, X represents -NH-, -NR''''-, or -CH2-, or a substituted carbon atom; and L is -NH2, -OH, -PO3H2-, -PO3H - , -PO3 2- -OPO3H2, -OPO3H - ,-OPO3 2- -COOH, -COO - -CO-NH2, -NH3 + -NH-CO-NH2, -N(CH3)3 + ,-N(C2H5)3 + ,-N(C3H7)3 + , -NH(CH3)2 + -NH(C2H5)2 + -NH(C3H7)2 + , -NHCH3, -NHC2H5, -NHC3H7, -NH2CH3 + , -NH2C2H5 + , -NH2C3H7 + -SO3H, -SO3 - -SO2NH2, -C(NH)-NH2, -NH-C(NH)-NH2, -NH-COOH, or

[0202] [ka] Represents a linear or branched saturated or unsaturated carbon chain of C1 to C8 having at least one substituent selected from the group comprising or consisting of .

[0203] R''' is -H, -CH=CH2, -CH2-CH=CH2, -C(CH3)=CH2, -CH=CH-CH3, -C2H4-CH=CH2, -CH3, -C2H5, -C3H7, -CH(CH3)2, -C4H9, -CH2-CH(CH3)2, -CH(CH3)-C2H5, -C(CH3)3, -C5H 11 , -CH(CH3)-C3H7, -CH2-CH(CH3)-C2H5, -CH(CH3)-CH(CH3)2, -C(CH3)2-C2H5, -CH2-C(CH3)3, -CH(C2H5)2, -C2H4-CH(CH3)2, -C6H 13 -C7H 15 Cyclo-C3H5, Cyclo-C4H7, Cyclo-C5H9, Cyclo-C6H 11 , represents -C≡CH, -C≡C-CH3, -CH2-C≡CH, -C2H4-C≡CH, and -CH2-C≡C-CH3.

[0204] The carbon chain L is preferably in the range of C1 to C7, more preferably in the range of C1 to C6, even more preferably in the range of C1 to C5, and most preferably in the range of C1 to C4.

[0205] Preferably, L represents -CH(NH2)-COOH, -CH2-CH(NH2)-COOH, -CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, or -CH2-CH2-CH2-CH2-CH2-CH(NH2)-COOH.

[0206] Preferred compounds having free guanidino and / or amidino groups have a common characteristic of general formula (I):

[0207] [ka]

[0208] During the ceremony, X represents -NH-, or -CH2-, or a substituted carbon atom; and L is -NH2, -OH, -PO3H2-, -PO3H - , -PO3 2- -OPO3H2, -OPO3H - ,-OPO3 2- -COOH, -COO - -CO-NH2, -NH3 + -NH-CO-NH2, -N(CH3)3 + ,-N(C2H5)3 + ,-N(C3H7)3 + , -NH(CH3)2 + -NH(C2H5)2 + -NH(C3H7)2 + , -NHCH3, -NHC2H5, -NHC3H7, -NH2CH3 + , -NH2C2H5 + , -NH2C3H7 + -SO3H, -SO3 - -SO2NH2, -C(NH)-NH2, -NH-C(NH)-NH2, -NH-COOH, or

[0209] [ka] Represents a linear or branched saturated or unsaturated carbon chain of C1 to C8 having at least one substituent selected from the group comprising or consisting of .

[0210] The carbon chain L is preferably in the range of C1 to C7, more preferably in the range of C1 to C6, even more preferably in the range of C1 to C5, and most preferably in the range of C1 to C4.

[0211] Preferably, L represents -CH(NH2)-COOH, -CH2-CH(NH2)-COOH, -CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, or -CH2-CH2-CH2-CH2-CH2-CH(NH2)-COOH.

[0212] The present invention preferably relates to a method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium, and the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Contacting a gas containing carbon dioxide with the acceptor solution in step a); and c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or Store and / or transport the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b). Includes, Here, the acceptor compound has general formula (I):

[0213] [ka]

[0214] During the ceremony, X represents -NH-, -NR''''-, or -CH2-, or a substituted carbon atom; and L is NH2, -OH, -PO3H2, -PO3H - , -PO3 2- -OPO3H2, -OPO3H - ,-OPO3 2- -COOH, -COO - -CO-NH2, -NH3 + -NH-CO-NH2, -N(CH3)3 + ,-N(C2H5)3 + ,-N(C3H7)3 + , -NH(CH3)2 + -NH(C2H5)2 + -NH(C3H7)2 + , -NHCH3, -NHC2H5, -NHC3H7, -NH2CH3 + , -NH2C2H5 +, -NH2C3H7 + -SO3H, -SO3 - -SO2NH2, -C(NH)-NH2, -NH-C(NH)-NH2, -NH-COOH, or

[0215] [ka] Represents a linear or branched saturated or unsaturated carbon chain of C1 to C8 having at least one substituent selected from the group comprising or consisting of;

[0216] R''' is -H, -CH=CH2, -CH2-CH=CH2, -C(CH3)=CH2, -CH=CH-CH3, -C2H4-CH=CH2, -CH3, -C2H5, -C3H7, -CH(CH3)2, -C4H9, -CH2-CH(CH3)2, -CH(CH3)-C2H5, -C(CH3)3, -C5H 11 , -CH(CH3)-C3H7, -CH2-CH(CH3)-C2H5, -CH(CH3)-CH(CH3)2, -C(CH3)2-C2H5, -CH2-C(CH3)3, -CH(C2H5)2, -C2H4-CH(CH3)2, -C6H 13 -C7H 15 Cyclo-C3H5, Cyclo-C4H7, Cyclo-C5H9, Cyclo-C6H 11 , represents -C≡CH, -C≡C-CH3, -CH2-C≡CH, -C2H4-C≡CH, and -CH2-C≡C-CH3. L is in the range of C1 to C7, more preferably in the range of C1 to C6, even more preferably in the range of C1 to C5, and most preferably in the range of C1 to C4, and L preferably represents -CH(NH2)-COOH, -CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH(NH2)-COOH, -CH2-CH2-CH2-CH2-CH(NH2)-COOH, or -CH2-CH2-CH2-CH2-CH2-CH(NH2)-COOH.

[0217] The acceptor solution according to the present invention does not have a guanidino group and / or an amidino group. The method may contain further compounds having effects that are advantageous to its implementation. These may be, for example, base-forming compounds such as lysine and histidine. Furthermore, the acceptor solution may contain compounds that have, for example, antimicrobial effects or alter the surface tension of the medium.

[0218] Preferably, the acceptor compound is an amino acid, and the pH of the acceptor solution is in the range of 8 to 13. In a more preferred embodiment, the aqueous acceptor medium comprises further compounds or additives. Preferred further compounds are, in particular, potassium hydroxide and sodium hydroxide. Surprisingly, the presence of these compounds allows for the separation of carbon dioxide, or carbonate anions / bicarbonate anions, bound to the acceptor medium using a low-energy input when a DC voltage is applied.

[0219] Caustic solutions of potassium (KOH) or sodium (NaOH) improve the electrical conductivity (electroactivity) of water in a concentration-dependent manner. The voltage at which electrolysis of water occurs also decreases, ranging from 0.6 to 2 volts depending on the selected electrode configuration. It was revealed that electrolysis of water did not occur in a mixture of a solution containing arginine as an acceptor compound with a potassium hydroxide solution or a sodium hydroxide solution, and this was also true when using potassium hydroxide solutions or sodium hydroxide solutions of the same concentration but without arginine. For example, when a voltage of 12V was applied to a 3% NaOH solution after 30 minutes in the electrolytic apparatus, 18.2 ml of oxygen was produced at the anode and 6.4 ml of hydrogen at the cathode. Using the same experimental setup, no gas formation was observed with a 2 molar concentration arginine solution containing 3 wt% NaOH. Using the same experimental setup with a 2 molar concentration arginine solution saturated with carbon dioxide, no gas formation was observed over a 30-minute period when a voltage of 12V was applied. When NaOH was added to this solution to the extent that a 3 wt% solution was present, 7.8 ml of gas was formed at the cathode, and no gas was formed at the anode under the same conditions (12 V). The gas formed / generated at the cathode was carbon dioxide. Therefore, it is possible to demonstrate that when a DC voltage is applied, bicarbonate anions / carbonate anions bound to the acceptor medium can be released at the cathode in the form of carbon dioxide in the presence of hydroxide ions. At DC voltages above 40 V, it was shown that even with a solution containing 4 wt% NaOH or KOH in an aqueous solution containing arginine and dissolved carbon dioxide / bicarbonate anions / carbonate anions, electrolysis of water leading to oxygen formation did not occur. However, at higher DC voltages, a considerable amount of carbon dioxide was generated at the cathode.

[0220] Therefore, surprisingly, the presence of potassium hydroxide and / or sodium hydroxide solution in the aqueous acceptor solution according to the present invention results in the separation of bicarbonate anions and carbonate anions, and the release of gaseous carbon dioxide at the cathode, while a DC voltage is applied to the carbon dioxide-rich acceptor solution. This prevents the electrolysis of water, i.e., prevents the production of oxygen and hydrogen. This allows for a highly efficient use of the power required to separate and recover carbon dioxide from the acceptor solution.

[0221] Next, it is revealed that the presence of a caustic alkali solution in the acceptor liquid increases the volume of the acceptor solution to absorb carbon dioxide, and that there is no formation of potassium carbonate or sodium carbonate as a solid, while this also applies when the acceptor compound in the present invention is not present in the acceptor medium. This means that carbon dioxide preferentially reacts with arginine.

[0222] Furthermore, it was shown that the presence of a caustic alkali solution does not affect the storage properties of the acceptor solution. In particular, spontaneous release of carbon dioxide from the acceptor solution in the presence of alkali was observed. do not have.

[0223] Therefore, the addition of a sodium hydroxide solution or a potassium hydroxide solution to an aqueous acceptor medium is a particularly preferred embodiment in the method according to the present invention. Preferably, NaOH and / or KOH are added to an aqueous acceptor solution to form a concentration between 0.01 wt% and 10 wt%, more preferably between 0.5 wt% and 8 wt%, more preferably between 1 wt% and 6 wt%, and more preferably between 2 wt% and 5 wt%. In a more preferred embodiment, the aqueous acceptor solution containing potassium hydroxide or sodium hydroxide is provided at a pH between 12 and 14.

[0224] Preferably, the aqueous acceptor medium containing the dissolved acceptor compound further comprises a potassium hydroxide and / or sodium hydroxide solution. Preferably, the addition of potassium hydroxide and / or sodium hydroxide solution to an acceptor solution containing dissolved carbon dioxide / bicarbonate anions / carbonate anions is a method that results in electrophoretic separation of bicarbonate anions / carbonate anions without electrolysis, and release accompanied by the formation of gaseous carbon dioxide as the gas phase.

[0225] The addition of NaOH or KOH, at high concentrations, leads to corrosiveness of the acceptor medium. For example, decomposition of electrode materials made of carbon or aluminum occurred.

[0226] We have demonstrated that the improvement in electrophoretic separation of carbon dioxide or its derivatives from an acceptor medium according to the present invention can also be achieved with sodium and / or potassium salts.

[0227] For example, when sodium citrate, sodium sulfate, or potassium tartrate was added to a 2 molar concentration arginine solution, and therefore 8 wt% to 14 wt% of the salt solution was present in each case, the electrophoretic separation of carbon dioxide was improved compared to the use of NaOH or KOH, while simultaneously maintaining the pH of the solution <12.5.

[0228] Investigations into the binding ability of aqueous acceptor solutions containing dissolved sodium and / or potassium salts to carbon dioxide or its water-soluble derivatives have shown that the binding ability can be increased as a function of concentration. Therefore, by providing aqueous acceptor solutions containing dissolved sodium and / or potassium salts in addition to the acceptor compound according to the present invention, the absorption capacity of the acceptor solution to carbon dioxide or its derivatives can be improved. Electrophoretic methods have shown that neither absorption nor desorption of carbon dioxide results in the formation of a solid.

[0229] The preferred concentration of the sodium or potassium salt in the acceptor solution according to the present invention is between 0.1 wt% and 25 wt%, more preferably between 1 wt% and 20 wt%, and even more preferably between 2 wt% and 15 wt%. The preferred counterion in the salt is: sulfate SO4 2 -, phosphate PO4 3 - These are acetates, citrates, tartrates, and oxalates. The salts can be added to the acceptor solution individually or in any combination. The pH of the acceptor solution containing the dissolved sodium and / or potassium salts is preferably between 8.0 and 13.5, more preferably between 8.5 and 13, and even more preferably between 9 and 12.5. The preferred acceptor solution containing the sodium and / or potassium salts is noncorrosive.

[0230] Preferably, an aqueous acceptor solution comprising at least one dissolved acceptor compound and at least one dissolved sodium and / or potassium salt is provided for carbon dioxide absorption, and carbon dioxide or a derivative of carbon dioxide is absorbed therein. This is a method of dissolving / binding.

[0231] We demonstrated that even from acceptor solutions containing sodium and / or potassium salts, loaded with carbon dioxide until saturated, carbon dioxide is not spontaneously released under atmospheric pressure.

[0232] Preferred is a method that allows carbon dioxide to be bound without pressure (at atmospheric pressure or normal pressure) for more than 12 months using an aqueous acceptor solution.

[0233] This property further demonstrates the ability to transport carbon dioxide into an aqueous acceptor solution without pressurization (at atmospheric or normal pressure). Preferably, this method allows carbon dioxide to be transported under no pressure (atmospheric pressure or normal pressure) using an aqueous acceptor solution. Preferably, this is a step that allows for the transport and / or storage of carbon dioxide / carbon dioxide derivatives bound to the acceptor solution.

[0234] Therefore, the challenge is as follows: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group. b) Contact the gas containing carbon dioxide with the acceptor solution in step a) until the concentration of gaseous carbon dioxide reaches <100 ppm. c) Transport and / or store the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative in step b), This is solved by a method for the selective binding, transport, and storage of carbon dioxide in an aqueous medium, characterized by [specific characteristics].

[0235] Preferably, the method is one in which the acceptor compound is an amino acid and the pH of the acceptor solution is in the range of 8 to 13. Preferably, the acceptor solution is prepared using deionized water (DI water). One or more acceptor compounds are preferably completely dissolved in water. In this method, the solution may be heated to increase the solubility of one or more compounds.

[0236] Surprisingly, it has been shown that the solubility of acceptor compounds can be significantly increased by contacting the acceptor solution with carbon dioxide during or after a thermal induction dissolution method of some acceptor compounds; therefore, in a preferred embodiment, the dissolution method of the acceptor compound is carried out while introducing carbon dioxide. In this method, it is possible to dissolve / add undissolved acceptor compounds to the solution or to further increase the concentration of the acceptor compound. As an example, it has been shown that concentrations of 5 mol / l or higher can be achieved using arginine. Furthermore, these solutions remain stable, i.e., crystallization of the acceptor compound does not occur.

[0237] Preferably, the solubility of the acceptor compound is increased by contacting the acceptor medium with a gas / gas mixture consisting of or containing carbon dioxide, and the acceptor compound exists in the acceptor medium in both a dissolved and / or undissolved form.

[0238] Preferably, a gas / gas mixture containing at least one gaseous compound that forms a water-soluble compound upon contact with water is brought into contact with an acceptor medium, and the water-soluble compound forms a reversible bond with the dissolved acceptor compound. This method involves a substance existing in an ionic or ionizable form within a medium.

[0239] Preferably, contact between the gas phase and the acceptor medium is carried out until the content of the gas / gas compound dissolved in the acceptor medium is <100 ppm. The carbon dioxide extraction according to the present invention is possible for various gases / gas mixtures and has been shown to yield very favorable results. For combustion gases from diesel and gasoline engines, as well as from coal blast furnaces, the carbon dioxide content is between 10 wt% and 25 wt%, and can be reduced to <0.01 vol.% by contacting the gas with an acceptor solution using a static mixer, for example. It is possible to remove 52 vol% of carbon dioxide present in gas mixtures from biogas production, obtaining biomethane with a purity of >98.5 vol%. It has been shown that gases or gaseous compounds that do not form acids upon contact with water do not bind to the acceptor compounds according to the present invention, and therefore there is no release from the gas / gas mixture contacted with the acceptor solution, nor are they present in the acceptor solution at concentrations higher than those at a given partial pressure established when the gas phase and acceptor medium are in contact. For example, oxygen, nitrogen, carbon monoxide, noble gases, or hydrocarbons such as methane and butane are not concentrated in the acceptor solution.

[0240] Preferably, this is a method for producing pure methane gas. Preferably, this is a method for producing pure biomethane gas. The present invention demonstrates that gaseous / gas compounds that form acids upon contact with water can be bound in an aqueous acceptor solution using the acceptor solution according to the present invention. When selective extraction and / or recovery of carbon dioxide is desired, it is advantageous to remove other gaseous / gas compounds that may compete for the absorption of carbon dioxide from the gaseous / gas mixture before contacting them with one of the acceptor compounds according to the present invention, as acids also form in water.

[0241] Preferably, this involves the removal or reduction of compounds from these gas / gas mixtures containing components such as SO2, H2S, NO, NO2, and other nitrogen oxides, or components such as Cl2 or HCl. This can be done, for example, by prior art methods such as catalysts, adsorbents, or aqueous gas scrubbing.

[0242] The gas / gas mixture to be brought into contact with the acceptor solution preferably has a temperature between 0°C and 100°C, more preferably between 10°C and 85°C, and even more preferably between 15°C and 70°C. In principle, the acceptor solution can also be used to cool the gas / gas mixture, and therefore higher temperature gas / gas mixtures are also possible. In this case, cooling of the solution should preferably be provided to avoid evaporation of the aqueous acceptor medium. The gas / gas mixture that can be obtained after contact with the aqueous acceptor medium may contain water vapor and water in droplet form, depending on the temperature, composition, volumetric flow rate, or contact type.

[0243] As a result, the acceptor solution and acceptor compound may be lost. Therefore, it is preferable to remove as much residual water as possible from the treated gas / gas mixture. This can be done, for example, using methods from the prior art, such as apparatus for condensate separation. The separated aqueous phase is then returned to the acceptor solution. The acceptor compound according to the present invention is not used up in the implementation of the method according to the present invention and is not subjected to autocatalytic methods. Therefore, the method addresses the economical method characteristics of reusing the acceptor compound without loss in a recirculation method. Preferably, a process-economic method is preferred in which the acceptor compound is reused without loss.

[0244] When using a membrane contactor, contact with a high-temperature dry gas stream does not result in any relevant losses in the aqueous acceptor solution. This is possible by selecting an appropriate membrane / solid separation medium. For example, a membrane contactor having a polycarbonate membrane as the interface can process gases with temperatures up to 150°C. When using a ceramic membrane, gas streams with temperatures >200°C can also be processed. Therefore, in a preferred process design, the extraction of water-soluble gases / gas components in a gas stream is performed by contacting the acceptor medium with the gas stream at the membrane contactor. In a particularly preferred process embodiment, contact with the aqueous acceptor medium of a gas stream containing at least one water-soluble gas component with a temperature up to 350°C is performed at the membrane contactor. Therefore, in a preferred embodiment of the process, the acceptor liquid (acceptor solution) is made from a membrane contactor for contacting a gas stream having or consisting of at least one water-soluble gas fraction, and is preferably introduced into the membrane contactor at a temperature range of 10°C to 400°C, more preferably 50°C to 350°C, and even more preferably 70°C to 300°C. Preferably, the method involves bringing a gas stream containing at least one water-soluble gaseous component and having a temperature of up to 350°C into contact with an aqueous acceptor medium in a membrane contactor.

[0245] Gaseous carbon dioxide is taken up very rapidly and completely at the interface with the acceptor medium, as long as acceptor compounds that are not involved in the carbon dioxide / carbonate anion / bicarbonate anion bonding are still present. A carbon dioxide saturated acceptor solution in which carbon dioxide is completely dissolved is clear, and there is no spontaneous release / generation of gas.

[0246] In this context, complete dissolution means that in a sealed container containing carbon dioxide / carbonate anions / hydrocarbon anions dissolved at 20°C, no vapor pressure exceeding 2 kPa is generated due to carbon dioxide.

[0247] For example, we demonstrated that degassing (generation of CO2 as a gaseous phase) can be achieved by lowering the pH of the acceptor medium. This can be done, for example, by adding an acid.

[0248] In the analysis of the gaseous flow obtained by degassing an aqueous acceptor solution containing compounds having guanidino and / or amidino groups, and carbon dioxide dissolved therein in a saturated form, no compounds other than carbon dioxide could be detected upon the addition of an acid (e.g., HCl).

[0249] The release / generation of carbon dioxide dissolved in the acceptor medium of the present invention, or in the form of a pure carbon dioxide gas phase of bound carbonate anions / carbonate anions, can be achieved by a method that leads to the protonation of the acceptor liquid (acceptor solution). In one embodiment of the method, for example, an acid from the prior art can be used.

[0250] These can be organic or inorganic acids. Preferred organic acids are formic acid or acetic acid. Preferred inorganic acids are hypochlorous acid (HCl) or sulfuric acid. The concentration of the acid and the volume ratio added to the acceptor solution are, in principle, freely selectable. Concentrated acids are preferred. By adding the acid, the pH of the acceptor solution is adjusted to preferably a range of 2 to 7, more preferably a range of 3 to 6, and more preferably a range of 3.5 to 5. Thus, removal of preferably >70 wt%, more preferably >80 wt%, and more preferably >90 wt% of carbon dioxide dissolved / bound in the acceptor solution, or its water-soluble derivatives, can be achieved and obtained as a pure carbon dioxide gas phase.

[0251] Preferably, the aqueous acceptor medium is saturated with a water-soluble gas, and then the acceptor The release / generation of water-soluble gases bound to the acceptor solution is achieved by adjusting the pH of the acceptor medium to a range between 2 and 7.

[0252] Preferably, the aqueous acceptor medium is saturated with a water-soluble gas, and the release / generation of the water-soluble gas bound to the acceptor liquid (acceptor solution) is achieved by adjusting the pH of the acceptor medium to a range between 2 and 7 by adding an acid.

[0253] The addition of an acid to the acceptor medium causes the introduction of anions, and their retention in the acceptor liquid has a detrimental effect on the reabsorption capacity of the acceptor compound to water-soluble gases or their derivatives. Therefore, in a preferred form of the method, following the introduction of anions that do not correspond to one of the water-soluble forms of the water-soluble gas / gas component treating the acceptor liquid (acceptor solution), the added anions are separated before the acceptor liquid (acceptor solution) is again exposed to the water-soluble gas / gas component. For this purpose, prior art methods are known. For example, Cl - (Chloride) or SO4 2-The removal of anions such as sulfates can be achieved by electrodialysis. However, such electrophoretic methods can also be used to remove organic acid residues, thereby achieving the regeneration of the acceptor solution. In a more preferred embodiment of the method, a caustic solution, such as potassium hydroxide solution or sodium hydroxide solution, is added to the acceptor solution to which the inorganic acid has been added. Preferably, the caustic solution is measured to produce an equimolar concentration ratio between the anions added to the acceptor medium on the one hand and the cations added by the addition of the caustic solution on the other hand.

[0254] Preferably, the salt obtained thereafter is separated. This can preferably be done by electrophoresis, for example, electrodialysis. The acceptor solution regenerated in this way can then be used for the new incorporation of water-soluble gases / gas components or the water-soluble derivatives.

[0255] However, other cationic compounds are also known in the prior art and can be used as an alternative to alkali to remove free anions and anions bound to acceptor compounds from aqueous acceptor media using one of the method types enumerated herein, thereby enabling the acceptor liquid (acceptor solution) to be used for new absorption of water-soluble gases / gasic components.

[0256] Preferably, the aqueous acceptor medium is saturated with a water-soluble gas, and the water-soluble gas bound to the acceptor liquid (acceptor solution) is released / generated by the addition of an acid, and the acceptor liquid (acceptor solution) is then regenerated by the addition of a caustic alkali solution, and the formed salt is then separated by electrophoretic separation.

[0257] In a more preferred embodiment, the pH of an acceptor solution saturated with a water-soluble gas / gas component, or the water-soluble derivative, is reduced by an electrochemical method. This can be achieved, for example, by introducing an acceptor solution containing a dissolved water-soluble gas / gas fraction, or the derivative, into an electrodialysis machine. Preferably, the electrodialysis chamber is configured such that the electrolyte chamber is connected to the acceptor chamber on the anode side. Preferably, there is a cation-selective membrane between the chambers. The water-soluble derivative of carbonic acid is then released / generated as carbon dioxide in the acceptor chamber.

[0258] Preferably, the aqueous acceptor medium is saturated with a water-soluble gas, and thereafter, the release / generation of the water-soluble gas bound to the acceptor liquid is performed by an electrochemical method. This method is achieved by adjusting the pH of the terminating medium to a range between 2 and 7.

[0259] Preferably, contacting the acceptor solution with a gas containing carbon dioxide is performed until the gas reaches a carbon dioxide concentration of <100 ppm, or after transporting and / or storing the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative, and the following method steps are performed: Release / generation of carbon dioxide bound to the acceptor medium as a gaseous phase.

[0260] In a more preferred embodiment of the method, the release of the gas fraction, or derivative, dissolved and bound in a water-soluble gas / aqueous acceptor medium, is carried out following spatial separation from the acceptor medium. In a preferred embodiment of the method, the dissolved and bound carbon dioxide / carbonate anion / bicarbonate anion is transported to an incorporation and release medium by electrophoresis. It is shown that a gas phase spontaneously forms in the incorporation and / or release medium according to the present invention to which the carbonate anion / bicarbonate anion has been transported. Only carbon dioxide was detected in the gas phase formed. Therefore, it is possible to selectively remove carbon dioxide from a gas mixture and release the carbon dioxide in an isolated form into a collection container without applying any pressure.

[0261] Surprisingly, we found that dissolved carbon dioxide / carbonate anions / bicarbonate anions can be separated very easily from the acceptor solution using a membrane method. This does not require any change in the pH of the acceptor solution. Therefore, we found that membranes permeable to gaseous compounds and / or anions are suitable for the selective transport of carbon dioxide / carbonate anions / bicarbonate anions. However, we also found that open-pore membranes / separation media are suitable for allowing the non-selective passage of carbon dioxide / carbonate anions / bicarbonate anions.

[0262] Surprisingly, open-pore membranes are particularly suitable for the separation of dissolved carbon dioxide / carbonate anions / bicarbonate anions from the aqueous medium of the present invention. Microporous or mesoporous membranes are preferred. However, macroporous and nanoporous membranes can also be used. The outer and inner membrane surfaces can be hydrophilic or hydrophobic. Hydrophobic membrane surfaces are preferred. Compared to anion exchange membranes or bipolar membranes consisting of sealed polymer films, the mass / volume flow rate of electrophoretically transported carbon dioxide / carbonate anions / bicarbonate anions can be significantly higher.

[0263] Preferably, the separation of dissolved carbon dioxide / carbonate anions / bicarbonate anions is carried out by an open-pore membrane. The open-pore membrane is preferably microporous and / or mesoporous and has hydrophobic surface properties.

[0264] Preferred transport methods for carbon dioxide / carbonate anions / bicarbonate anions are based on diffusion, concentration gradients, thermal or electrical gradients, or combinations thereof. Preferably, the separation medium (separation membrane) is an open-pore membrane, i.e., a solid or semi-solid separation medium (separation membrane) suitable for holding an aqueous medium without pressurization, with both sides of the membrane connected and having open pores permeable to gases and / or anions. Preferably, the open pores have an average diameter between 10 nm and 1 mm, more preferably between 100 nm and 500 micrometers, and more preferably between 1 micrometer and 200 micrometers. Preferred membranes exhibit hydrophilic or hydrophobic electrostatic properties on the inner and / or outer surfaces of the membrane.

[0265] Due to the saturation of the acceptor medium according to the present invention, the carbon dioxide was completely bound, and therefore there was no separation and no increase in pressure in the acceptor chamber. This means that the separation method for separating dissolved carbon dioxide or its reaction products is based on the acceptor medium This is particularly advantageous because it is carried out using an open-pore separation membrane, which does not require pressure equalization between the containers containing the intake and / or release media. This allows the receiving device for the intake and / or release media to be exposed to atmospheric pressure. In a preferred embodiment, the receiving device (chamber) for the acceptor media and the intake and / or release media is exposed to atmospheric pressure.

[0266] Surprisingly, when an aqueous solution containing acid was placed in a chamber unit adjacent to the acceptor chamber, confluent bubbles formed very rapidly on both sides of the separation membrane. Therefore, by diffusion, carbonate anions / bicarbonate anions pass through the separation medium (separation membrane) into the chamber unit adjacent to the acceptor chamber where the acid is placed, and release carbon dioxide. Hereafter, this chamber unit will be referred to as the intake and release chamber. Consequently, the medium contained in the intake and release chamber will be referred to as the intake and release medium.

[0267] As described below, other separation media can also be used to enable the transport of carbon dioxide / carbonate anions / hydrocarbon anions from aqueous acceptor media in the intake and release media.

[0268] Preferably, the separation of carbon dioxide / carbonate anions / bicarbonate anions from an aqueous acceptor medium is carried out through a separation medium (separation membrane), and thereby they are taken into and / or released into an incorporation and release medium.

[0269] Preferably, the separation of carbon dioxide / carbonate anions / bicarbonate anions from an aqueous acceptor medium is carried out by a separation medium (membrane) based on diffusion, osmosis, and / or electrophoresis.

[0270] Preferably, the separation medium for separating carbon dioxide / carbonate anions / bicarbonate anions from an aqueous acceptor medium is a solid or semi-solid separation medium (separation membrane) that can hold the aqueous medium without pressurization (at atmospheric pressure) and has open pores connecting both sides of the membrane that allow gas and / or anions to pass through.

[0271] Preferably, the method involves a separation membrane as the solid or semi-separated separation medium (separation membrane) for separating carbon dioxide / carbonate anions / bicarbonate anions. Preferably, the separation membrane for separating carbon dioxide / carbonate anions / bicarbonate anions is an anion-selective or bipolar polymer membrane.

[0272] Remarkably, dissolved carbon dioxide, or carbonate anions / bicarbonate anions, can be separated very efficiently from the acceptor solution of the present invention using electrophoresis.

[0273] Preferably, electrodialysis is performed to separate the dissolved carbon dioxide / bicarbonate anions. In this regard, electrodialysis can be performed using prior art methods and apparatus.

[0274] We have shown that electrophoretically transported carbon dioxide / carbonate anions / bicarbonate anions are separated in an uptake and / or release medium containing anionic amino acids and released as gaseous carbon dioxide.

[0275] In an embodiment of the preferred method, the separation of carbon dioxide / carbonate anions / bicarbonate anions from an aqueous acceptor medium is performed using a method that includes carbon dioxide / carbonate anions / bicarbonate anions. This is done by filling the acceptor chamber with the acceptor medium and separating it from the take-up and release chamber adjacent to the acceptor chamber by a separation medium (separation membrane). The take-up and release chamber preferably contains the take-up and / or release medium. The take-up and / or release medium is preferably an aqueous medium. Preferably, the aqueous medium has a pH in the range of 1 to 7, more preferably 2 to 6, and more preferably 3 to 5. In a particularly preferred embodiment, a compound having an acid group is dissolved in the take-up and / or release medium. Particularly preferred is a compound having at least one acid group and an isoelectric point in the range of 3 to 5, or more preferably 3.5 to 4.5. Particularly preferred are amino acids having an acid group, particularly aspartic acid and glutamic acid. Preferred concentrations are in the range of 1 mmol / l to 3 mol / l. Even more preferred are organic acids having two or more acid groups and good water solubility, such as citric acid or ascorbic acid. In principle, inorganic acids such as sulfuric acid or diphosphate are also suitable. When inorganic acids are used, aqueous solutions of these acids having concentrations between 1 wt% and 50 wt% are preferred. Furthermore, mixtures of different acids are preferred. The temperature range in which the incorporation and release media are used can, in principle, be freely selected between 1°C and 99°C. Preferably, it is between 30°C and 80°C, more preferably between 40°C and 75°C, and even more preferably between 50°C and 70°C.

[0276] Preferably, the method involves an incorporation and emission chamber comprising an incorporation and / or emission medium, containing at least one compound, the at least one compound having at least one acid group, and having an isoelectric point in the range of 3 to 5.

[0277] Preferably, the method involves the uptake and / or release medium being an aqueous solution of an organic acid and / or an inorganic acid. Surprisingly, embodiments of this method have been shown to be suitable for enabling the selective transport of carbon dioxide or carbonate anions / bicarbonate anions to an incorporation and release chamber, or to an incorporation and / or release medium, thereby allowing carbon dioxide to be released / generated from the incorporation and / or release medium, and gaseous carbon dioxide to be formed from carbonate anions / bicarbonate anions by the decomposition of water, thus forming a gaseous phase in which only carbon dioxide exists. Thus, it is possible to selectively bind and transport carbon dioxide and selectively release it at any desired location.

[0278] In a preferred embodiment of the method, there is a continuous or discontinuous flow in the intake and release medium through the intake and release chamber, preferably with a high overflow velocity at the surface of the release medium (separation membrane), thereby completely or almost completely preventing gas generation at the surface of the release medium (separation membrane), and the intake of bicarbonate anions / carbonate anions into the intake and release medium is achieved, and thereafter the bicarbonate anions / carbonate anions are introduced into a separate container, where gas release / release then takes place. It has been shown to be particularly advantageous if the release / removal of carbon dioxide is as complete as possible in this separate release container, and the intake and release medium is returned to the intake and release chamber, thereby greatly increasing the transport properties both through the separation medium and in the intake and release medium (see Figure 1). Efficient degassing in the intake and release medium can be achieved, for example, by flowing over a surface. Preferably, the surface is a hydrophobic surface made of a material such as PTFE or graphite. Furthermore, degassing can be achieved by known techniques such as the application of vacuum, ultrasound, and shear force, and / or heating of the intake and release media, for example, to generate cavitation.

[0279] In a preferred embodiment, carbon dioxide / carbonate anion / from an aqueous acceptor medium The separation of bicarbonate anions is performed by electrodialysis. In this method, an acceptor solution containing carbon dioxide or the reaction product of carbon dioxide with water is supplied to the acceptor chamber of an electrodialysis unit. In its simplest form, the electrodialysis unit consists of an acceptor chamber and an intake and release chamber, which are separated from each other by a separation medium (separation membrane).

[0280] The electrodes can be placed directly in the process medium, i.e., the anode can be placed in the intake and / or emission medium, and the cathode can be placed in the acceptor solution.

[0281] More preferably, the electrodialysis apparatus is configured such that electrodes are arranged in an anode chamber or cathode chamber (electrode chamber), and an acceptor chamber or intake and emission chamber is separated from the electrode chamber, the anode chamber and cathode chamber which are filled with an electron transport medium, such as an electrolytic solution, by an ion-selective membrane (see Figure 1). In a further preferred embodiment, a plurality of chamber units consisting of acceptor chambers and intake and emission chambers are joined together in a repeating configuration, and the chamber stack is terminated at both ends by the anode chamber and cathode chamber, respectively, where they are electrically conductively connected. In a preferred process configuration, the first acceptor chamber is adjacent to the cathode chamber, and the last intake and emission chamber is adjacent to the anode chamber. In a further preferred process embodiment, each acceptor chamber is separated from the intake and emission chamber by a bipolar membrane.

[0282] Preferably, the transport of carbon dioxide or carbonate anions / bicarbonate anions is carried out by applying a DC voltage between the cathode and anode. The voltage and current used to perform electrodialysis according to the present invention depend on specific process parameters, such as the distance between electrodes, the number of chamber units, the resistance of the membrane, and the resistance of the process solution, as well as the cross-sectional area, and are therefore determined individually.

[0283] In a preferred embodiment, carbon dioxide transported through a separation medium (separation membrane) is released as a gas in an intake and release chamber containing an intake / release medium. In a more preferred embodiment, carbon dioxide or a carbon dioxide derivative transported through a separation medium (separation membrane) is taken into an intake / release medium and released as a gas in a release device.

[0284] Preferably, step b) or step c) is followed by step c1) or step d1): release of carbon dioxide bound in the acceptor medium as a gas phase.

[0285] Preferably, the acceptor medium from step b) is placed in the acceptor chamber of the electrodialysis machine or introduced into the acceptor chamber of the electrodialysis machine, and the transport of carbon dioxide / carbon dioxide derivatives in step c) is carried out by an electrical gradient established between the acceptor chambers and the intake and release chambers, which are separated from each other by a separation medium (separation membrane), and between a plurality of acceptor chambers and the intake and release chambers.

[0286] Preferably, the method involves transporting carbon dioxide / carbon dioxide derivatives through a separation medium (separation membrane), where the separation medium is a membrane permeable to ions and / or gas molecules.

[0287] Preferably, the method for electrodialysis of the acceptor medium and transport of carbon dioxide / carbon dioxide derivatives according to step c) using an electrical gradient established between the acceptor chamber and the intake and release chamber, wherein the separation medium is a membrane permeable to ions and / or gas molecules.

[0288] Preferably, the release / generation of carbon dioxide / carbon dioxide derivatives transported through a separation medium (separation membrane) is carried out in the form of pure carbon dioxide gas within the intake and release chamber.

[0289] Preferably, carbon dioxide / carbonate anions / bicarbonate anions transported through a separation medium (separation membrane) are released in the form of pure carbon dioxide gas within an intake and release chamber.

[0290] Preferably, step b) or step c) is followed by the following steps b2) or c2): separation of carbon dioxide / carbonate anions / bicarbonate anions from the acceptor medium through a separation medium (separation membrane) by diffusion, osmosis, or electrophoresis, and transport to an uptake / release medium, where the release of carbon dioxide as a pure gaseous phase is achieved in the uptake / release medium.

[0291] Preferably, step b) or step c) is followed by the following steps b3) or c3): separation of carbon dioxide / carbonate anions / bicarbonate anions from the acceptor medium through a separation medium (separation membrane) by diffusion, osmosis, or electrophoresis, and transport to an uptake / release medium, where the release of carbon dioxide as a pure gaseous phase from the uptake / release medium is achieved in the release device.

[0292] Preferably, step c) is followed by the following steps c3') and c3): c3'): introducing the aqueous uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c) into the release device; and c3): releasing carbon dioxide as a gaseous phase from the uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c3') in the release chamber.

[0293] Preferably, the acceptor medium from step b) is placed in or introduced into the cathode chamber of the electrodialysis apparatus, and the transport of carbon dioxide / carbon dioxide derivatives in step c) is carried out by an electrical gradient established between the cathode chambers and anode chambers separated from each other by an ion-permeable or gas-permeable separation medium (separation membrane), and between multiple cathode chambers and multiple anode chambers.

[0294] In a preferred embodiment, a chamber for releasing or capable of releasing carbon dioxide is preferably provided together with a gas collector that prevents a pressure increase from occurring within the chamber.

[0295] In a preferred embodiment, carbon dioxide released after any of the methods following coupling in the acceptor medium is collected by a gas collector and supplied from there for further use (see Figure 1).

[0296] A preferred method involves releasing carbon dioxide as a gaseous phase again after binding / transportation or storage in an acceptor medium, and then supplying it for further use. In a more preferred embodiment of the method according to the present invention, the process configuration according to the present invention is: In addition to the separation and selective release of water-soluble gases / gaseous components, it is used to produce hydrogen and oxygen. In a preferred process embodiment, an electrodialysis apparatus is used for the transport of carbon dioxide / carbonate anions / bicarbonate anions, and generally, a voltage must be applied to cause electrolysis in each selected electrolyte solution so that electrolysis of water occurs in the electrode chamber. A chamber arrangement consisting of an acceptor chamber and intake and release chambers can be introduced into the process arrangement for electrolysis, thereby significantly increasing the energy efficiency of the method according to the present invention. Further availability of hydrogen and oxygen allows for very high energy efficiency in the method, which is preferably >90%, more preferably >95%, and even more preferably >98%.

[0297] In a more preferred embodiment, the release / generation of a gas fraction dissolved in a water-soluble gas / aqueous acceptor medium is performed at the cathode. Surprisingly, the acceptor solution according to the present invention was found to be suitable for suppressing the electrolysis of water that results in the formation of oxygen and hydrogen when a DC voltage is applied, even though there is a current flow due to the conductivity of the acceptor solution. This phenomenon was particularly evident when arginine was used as the acceptor compound. Thus, molecular charge transfer occurs. It was found that molecular charge transfer occurs preferentially over electrolysis as the distance between the anode and cathode increases. Therefore, gas formation was not observed even when a voltage of 40V and a low amperage current flow (<200mA) were applied. Furthermore, it was unexpected to observe that, in the presence of a solution containing potassium hydroxide or sodium hydroxide in the acceptor solution containing dissolved arginine, electrolysis of water was observed at the same voltage and current settings using a solution containing pure potassium hydroxide or sodium hydroxide of the same concentration, but there was no electrolysis of water resulting in the formation of hydrogen or oxygen.

[0298] Therefore, selective charge transfer is achieved via the dissolved acceptor compound. Next, when the acceptor solution was loaded with a water-soluble gas, it was revealed that gas formation was evident only at the anode when a DC voltage was applied, accompanied by the formation of a water-soluble derivative in the acceptor solution. When carbon dioxide was used as the water-soluble gas to which the acceptor liquid acceptor solution was exposed, the gas formed at the cathode consisted of pure carbon dioxide. Thus, a method was revealed in which the water-soluble form of the water-soluble gas can be selectively released / generated as a gas at the cathode via internal charge transfer in the acceptor solution when a DC voltage is applied.

[0299] Preferably, an aqueous solution containing dissolved arginine is subjected to a DC voltage, which inhibits the electrolysis of water and leads to the formation of hydrogen or oxygen.

[0300] Preferably, a solution containing dissolved arginine is used in a method that brings about molecular charge transfer when a DC voltage is applied to the aqueous solution. Preferably, when a DC voltage is applied, electrolysis can be suppressed by providing an acceptor solution. Preferably, the gas dissolved in the acceptor aqueous solution, or the water-soluble derivative thereof, can be released / generated as a gaseous phase at the cathode under the application of a DC voltage, and the method does not involve electrolysis resulting in the formation of hydrogen or oxygen.

[0301] Therefore, the separation of water-soluble derivatives in water-soluble gases can be achieved by applying a DC voltage, and without electrical loss due to electrolysis resulting in the formation of oxygen or hydrogen. In principle, this method can be carried out using apparatus for electrodialysis from the prior art. Depending on the energy density generated at the electrodes when a DC voltage is applied, the distance between the electrodes should be chosen to be large enough so that oxygen is not formed. This indicates that (it is evident from the absence of gas formation at the anode). Therefore, given a given configuration of electrodes and a given distance between them, the voltage can be selected such that there is no gas formation at the electrodes when applied to an unloaded acceptor solution. It is advantageous to use electrodes with a large surface area. It is even more advantageous if the surface area of ​​the anode is greater than the surface area of ​​the cathode. In an advantageous embodiment, the anode chamber and the cathode chamber are separated by a separation medium (membrane), resulting in electrically interconnected anode and cathode chambers.

[0302] It is advantageous for the separation medium (membrane) to have the lowest possible electrical resistance. Preferably, the separation medium (membrane) should be open-pore but should prevent gas passage. In a preferred embodiment, there are direct and open connections between the chambers so that the acceptor fluid can pass freely below the electrode level, at the electrode level, or both. In a more preferred embodiment, the flow through the electrode chambers is achieved by introducing an acceptor liquid loaded with an aqueous gas into the cathode chamber and passing the solution continuously through to the anode chamber. The solution passes through the open connections and / or separation medium (separation membrane), which are located between the electrode chambers and through which the liquid can pass. This clearly allows for a significant increase in the separation / generation of the gaseous phase in gases dissolved in aqueous acceptor medium, or in their aqueous derivatives.

[0303] In principle, electrode materials can be freely selected. If potassium hydroxide or sodium hydroxide is present in the acceptor medium in addition to the acceptor compound according to the present invention, the selection must be adapted accordingly. Preferred electrode materials are graphite, nickel, stainless steel, platinum, or gold. Combinations of materials for the anode and cathode, and mixed alloys are also preferred. The electrical DC voltage preferably applied between the anode and cathode depends on the electrode configuration and the distance between the electrodes, and therefore must be determined individually. The maximum possible voltage that does not cause the formation of hydrogen and oxygen can be determined based on tests in oxygen formation at the anode; in this context, the selected voltage must be lower than the voltage at which oxygen is formed as a gaseous phase.

[0304] In this regard, the method according to the present invention further addresses the cathodic separation / generation of carbon dioxide or other water-soluble gases as a pure gaseous phase from an aqueous acceptor medium.

[0305] Preferably, the cathode separation in a water-soluble gas is performed using an aqueous acceptor medium. Preferably, the method involves separating the dissolved gas or water-soluble derivative from the aqueous acceptor medium in the form of a pure gaseous phase by performing cathode separation in the aqueous acceptor medium.

[0306] In a more preferred embodiment, one or more compounds are present in the acceptor and / or release medium that react with and / or combine with carbon dioxide or carbonate anions / bicarbonate anions transported from the acceptor solution. These compounds, hereafter referred to as reaction compounds, may be in liquid, solid, or gaseous state. Furthermore, reaction-promoting compounds, such as catalysts, may be present in the take-up and release mediums. In this regard, the take-up and release mediums may be at different temperatures from the acceptor medium. In a more preferred embodiment, the reaction and / or combination of carbon dioxide / carbonate anions / bicarbonate anions dissolved in the acceptor medium is achieved using / by appropriate compounds present therein. Preferably, this involves the use of reaction compounds for the reaction and / or combination of carbon dioxide and / or carbonate anions / bicarbonate anions present in the acceptor solution and / or the take-up and release medium.

[0307] Preferably, one or more reaction compounds for reacting and / or binding carbon dioxide and / or carbonate anions / bicarbonate anions are present in the acceptor solution and / or incorporation and / or release medium.

[0308] Surprisingly, reaction conditions present in acceptor solutions containing high concentrations of carbon dioxide and / or carbonate / bicarbonate anions are particularly suitable for the synthesis of carbon compounds. For example, the synthesis of carboxylic acids can be achieved, including reactions using Grignard reagents or short-chain condensations using palladium catalysts. Preferred carbon compounds include, but are not limited to, formic acid, methanol, carbon monoxide (CO), and formaldehyde. The concentration of carbon dioxide and its water-soluble derivatives, made possible by the method, has been shown to enable the chemical synthesis of organic compounds under atmospheric pressure conditions. It has also been shown that carboxylic acids synthesized in aqueous acceptor media can be continuously separated by electrodialysis.

[0309] The electrophoretically separated carboxylic acid is preferably incorporated into an aqueous medium and released therefrom. Next, the solution containing dissolved arginine is shown to be very suitable in this embodiment of the method for use as an incorporation and / or release medium for the transported carboxylic acid.

[0310] Preferably, one or more reaction compounds for reacting and / or binding carbon dioxide and / or carbonate anions / bicarbonate anions are present in the acceptor solution and / or incorporation and / or release medium.

[0311] Preferably, after step b), the carbon dioxide bound in the acceptor solution is reacted with a reactant compound to form a carbon compound. In a particularly preferred embodiment, an anion exchange membrane permeable to anions having a molecular weight of up to 400 Da is used for selective electrophoretic transport of short-chain carboxylic acids.

[0312] This specification demonstrates that the total carbon dioxide content in flue gas can be separated, transported, and chemically converted by one of the methods described herein.

[0313] [Conversion method] Preferably, after step b), the carbon dioxide bound in the receptor solution is converted into a carbon compound by a reaction compound.

[0314] Preferably, after step c), the carbon dioxide bound to the acceptor and / or release medium, or the transported and released carbon dioxide, is converted into a carbon compound using a reaction compound.

[0315] Therefore, it was demonstrated that it is possible to increase the content / concentration of carbon dioxide and carbonate anions / bicarbonate anions in the aqueous acceptor medium under atmospheric pressure conditions, and at the same time, to establish optimal reaction conditions and thus enable immediate chemical transformation by the immobilized reaction-promoting compound in the acceptor solution. Furthermore, it was shown that by using the method configuration according to the present invention, it is possible to continuously remove reactants resulting from the chemical transformation, such as carboxylic acids, and that this can be done, for example, using an anion exchange membrane. Furthermore, in the embodiment of the method, it was shown that a solution containing a compound having a guanidino group or amidino group dissolved in the incorporation and release medium is suitable for the incorporation and transport of carboxylic acids resulting from the previous reaction, and that the carboxylic acids resulting from the previous reaction are transported by electrodialysis. They are doing it.

[0316] Preferably, it is a method for producing carbon compounds from carbon dioxide. In a more preferred embodiment, the chemical conversion of carbon dioxide bound to an aqueous acceptor medium in the form of a carbonate anion / bicarbonate anion to a carbonate is carried out.

[0317] Surprisingly, we have revealed that the chemical transformation can be carried out using various method configurations by absorbing carbon dioxide and its reaction products with water according to the present invention. As an example, three possible types of transformation methods are listed here.

[0318] Conversion method 1: Surprisingly, it was revealed that carbon dioxide dissolved in an aqueous acceptor medium, as well as carbonate anions and bicarbonate anions, can react in or directly with the acceptor solution to form carbonates. For this purpose, a solution containing a cationic compound suitable for carbonate formation in a dissolved (ionized) form is added to an acceptor solution already containing carbon dioxide or a water-soluble derivative of carbon dioxide in a dissolved / bound form.

[0319] In this case, the chemical transformation is achieved when the solution containing the reaction compounds is preferably introduced into a saturated acceptor solution. In another preferred embodiment of this conversion method, a carbonate is produced when an acceptor solution in which a salt of a cationic compound used for the production of a carbonate / bicarbonate is already dissolved comes into contact with carbon dioxide.

[0320] In another embodiment, an acceptor solution already present in the form of dissolved / bound carbon dioxide or a water-soluble derivative of carbon dioxide is added to a solution present in the form of dissolved (ionized) cationic / cationic compounds suitable for carbonate formation. A chemical transformation occurs when a saturated acceptor solution is introduced.

[0321] In all different methods, a milky suspension rapidly forms, from which the solid naturally separates by sedimentation. However, phase separation can also be achieved by prior art filtration or centrifugal methods.

[0322] Conversion method 2: In a more preferred embodiment, the addition of a cationic compound suitable for carbonate / bicarbonate production to an acceptor solution is carried out by electrophoresis during or after contact of the acceptor solution with a water-soluble gas / gaseous component, such as carbon dioxide. Preferably, this is done by electrodialysis. Preferably, this is carried out in a configuration in which the acceptor chamber is adjacent to the electrolyte chamber on the anode side and separated from the electrolyte chamber by a cation-selective membrane. In the electrolyte chamber, the cationic compound is present in a dissolved (ionized) form, which is suitable for carbonate / bicarbonate production. By applying a DC voltage, electrophoretic transport of the cationic compound is brought through the cation-selective membrane to the acceptor solution, where the cationic compound is then spontaneously converted to the corresponding carbonate. In this method, the acceptor solution may be saturated with carbon dioxide beforehand, or may be contacted with carbon dioxide during or after electrodialysis.

[0323] In a more preferred embodiment of this method, the cationic / cationic compound suitable for carbonate / bicarbonate production is present in ionic form in the incorporation and release medium. Carbon dioxide / carbonate anions / bicarbonate anions pass through an anion-selective separation medium (separation membrane). The compounds are then transported from the acceptor chamber to the incorporation and release medium. The corresponding carbonates are then formed in this medium. It was revealed that most of this reaction occurs directly in the separation medium (separation membrane). Surprisingly, this reaction proceeded more rapidly and uniformly in the aqueous incorporation and release medium when one of the acceptor compounds in the present invention was dissolved therein. It was also shown that bipolar membranes can be used for this purpose. This method is advantageous when inorganic acids are absent, or only small amounts of organic acids are present, in the incorporation and release medium.

[0324] Conversion method 3 In a more preferred embodiment of this method, the chemical conversion of carbon dioxide and / or carbonate anions and / or bicarbonate anions is achieved in the uptake and release medium, thereby, on the one hand, carbon dioxide and / or carbonate anions and / or bicarbonate anions are transported from the acceptor chamber through the separation medium (separation membrane) to the uptake and release chamber, and on the other hand, cationic compounds suitable for the formation of carbonates / bicarbonates are transported from the electrolyte chamber to the uptake and release chamber, in which at least one cationic compound is present in the electrolyte chamber in an ion or ionizable form.

[0325] The uptake and release chambers are adjacent to the acceptor chamber on the cathode side and adjacent to the electrolyte chamber on the anode side. Preferably, mass transfer is brought about electrophoretically using a bipolar or anion-selective membrane used as a separation medium (separation membrane) between the acceptor chamber and the uptake and release chamber, and a cation-selective membrane used between the uptake and release medium and the electrolyte chamber. In embodiments of this method, it is advantageous and preferable that at least one acceptor compound is present in a dissolved form in the uptake and release medium. It is preferable that there are no inorganic acids in the uptake and release medium, and that only small amounts of organic acids are present.

[0326] In all embodiments of the conversion process, it is advantageous to stir the aqueous solution in which the chemical conversion is carried out to prevent localized separation steps. In the process embodiments of the present invention, carbon dioxide is not released as a gaseous phase, or is substantially not released, during the chemical conversion. Separation may be caused by the concentration of counterions of the compounds used to produce carbonates. Therefore, it is advantageous to remove counterions from the process solution in which the chemical conversion of carbon dioxide and / or carbonate anions and / or bicarbonate anions is carried out.

[0327] Preferably, the removal of counterions (anions) in compounds used to provide cationic / cationic compounds for the preparation of carbonates is carried out during or after one of the conversion steps. These are, for example, Cl - or SO4 2- Therefore, in a preferred method embodiment, the counterion accumulation chamber unit is connected at the anode side to either an anode chamber or a rinsing chamber using an anion-selective membrane. In the rinsing chamber, there is an aqueous conductive medium which adsorbs counterions, and in the rinsing chamber, the counterions are adsorbed, or the rinsing solution is recirculated through the anode chamber. In a preferred embodiment, an acid, such as hydrochloric acid or sulfuric acid, may be formed in the anode chamber and used to further concentrate these to produce a solution containing a cationic / cationic compound suitable for the production of carbonates. For example, aluminum chloride or ferrous sulfate can be produced by this method from metallic aluminum or iron and then used for the production of further carbonates / bicarbonates.

[0328] The implementation of conversion methods 2 and 3 does not result in the formation of solid aggregates in the acceptor medium and may involve further actions that could compete with the uptake of carbonate anions / bicarbonate anions. This method is particularly advantageous because no anions are introduced. This allows the acceptor solution to be circulated for the uptake and release of carbon dioxide and / or carbonate anions and / or bicarbonate anions, which then chemically react in the secondary circulation method. In conversion method 1, continuous or discontinuous separation of anions other than carbonate anions and / or bicarbonate anions can be performed by adsorption or electrodialysis. Therefore, recirculation in the acceptor solution can also be ensured in conversion method 1.

[0329] Cl remaining in the acceptor solution after carbonate formation - or SO42- The separation of counterions such as, when adding potassium hydroxide solution or sodium hydroxide solution to this solution, can also be achieved with lower energy input in the process of electrodialysis has also been clarified.

[0330] Preferably, the dosage is titrated to the pH of a solution in which the counterion is completely dissolved from the receptor compound. This converts the cations remaining in the acceptor solution added during the recirculation of the acceptor solution for the adsorption of water-soluble gas into their hydroxide forms, such as Ca(OH)2 etc., by which they become solids, separation becomes very easy, and as a result, it is further particularly advantageous because there is no formation of solids (formation of carbonates) in the gas scrubbing device during the recirculation of the acceptor solution. Following the separation of the solids formed after titration using potassium hydroxide solution or sodium hydroxide solution, the acceptor solution is purified by electrodialysis from the salt components contained (e.g., Na + , K + , Cl - or SO4 2- ). Subsequently, an acceptor solution having an absorption capacity corresponding to the absorption capacity of the initially used acceptor solution can be used to reabsorb the water-soluble gas / gas components.

[0331] The conversion method according to the present invention is preferably carried out in a temperature range between 5°C and 70°C, more preferably between 10°C and 60°C, still more preferably between 15°C and 50°C. The pH of the aqueous solution for generating carbonate / bicarbonate is preferably in the range between 5 and 13, more preferably between 6 and 12.5, still more preferably between 7 and 12. The generation of carbonate / bicarbonate is preferably carried out under normal pressure conditions.

[0332] In a more preferred embodiment, the chemical conversion according to one of the conversion methods is carried out by performing the conversion at high pressure and / or high temperature and / or in the presence of a catalyst.

[0333] However, the conversion method is also suitable for contacting other compounds with carbon dioxide and / or carbonate anions and / or bicarbonate anions and causing them to chemically react with each other. Therefore, in a preferred method embodiment, one or more compounds, hereafter also called reaction compounds, are added to an aqueous acceptor medium and one or more compounds are used to contact carbon dioxide and / or carbonate anions and / or bicarbonate anions before, and / or during, and / or after the absorption of carbon dioxide in the acceptor solution and cause them to react with each other. In a more preferred method embodiment, the chemical conversion of carbon dioxide and / or carbonate anions and / or bicarbonate anions is carried out via the transport of carbon dioxide and / or carbonate anions and / or bicarbonate anions to an uptake and release medium containing or transporting one or more reaction compounds in a carbon dioxide and / or carbonate anion and / or bicarbonate anion absorption step that is carried out in parallel with or following the carbon dioxide and / or carbonate anion and / or bicarbonate anion absorption step according to the present invention.

[0334] Preferably, at least one reaction compound is present in the aqueous acceptor medium, and the reaction with carbon dioxide and / or carbonate anion and / or bicarbonate anion is This method is brought about during and / or after the adsorption of carbon dioxide in the acceptor solution.

[0335] Preferably, the method involves adsorption of carbon dioxide in an acceptor solution using an aqueous acceptor medium, contacting an aqueous absorbent medium containing carbon dioxide and / or carbonate anions and / or bicarbonate anions with at least one reaction compound, and allowing the reaction between the at least one reaction compound and carbon dioxide and / or carbonate anions and / or bicarbonate anions to take place.

[0336] Preferably, at least one reaction compound is present in an uptake and release medium for carbon dioxide and / or carbonate anions and / or bicarbonate anions, and the reaction with carbon dioxide and / or carbonate anions and / or bicarbonate anions is achieved therein, wherein at least one reaction compound is transported through a separation medium (membrane) between an acceptor chamber and an uptake and release chamber.

[0337] Preferably, the method involves the presence of at least one reaction compound and at least one acceptor compound in the uptake and release medium, and the chemical reaction with carbon dioxide and / or carbonate anions and / or bicarbonate anions transported through a separation medium (membrane) between the acceptor chamber and the uptake and release chamber taking place in the uptake and release medium.

[0338] Preferably, the adsorption of carbon dioxide in the acceptor solution is brought about using an aqueous acceptor medium, and the adsorbed carbon dioxide and / or carbonate anions and / or bicarbonate anions are transported through a separation medium (membrane) to a reaction chamber containing at least one dissolved reaction compound, where they react with the reaction compound.

[0339] Preferably, the method involves the adsorption of carbon dioxide in the acceptor solution by an aqueous acceptor medium, the adsorbed carbon dioxide and / or carbonate anions and / or bicarbonate anions being transported through a separation medium (membrane) to a reaction chamber, and at least one reaction compound being transported from the electrolyte chamber to the reaction chamber before, / or during, and / or after the transport of carbon dioxide and / or carbonate anions and / or bicarbonate anions to the reaction chamber, wherein the at least one reaction compound is present in a dissolved form and the transport of the compound is carried out electrophoretically.

[0340] The residual amounts of acceptor compounds and / or anions of the reaction compounds used, contained in the solid obtained by phase separation, can be completely removed, for example, by washing methods.

[0341] It has been shown that the resulting solid can be dried very easily. This is achieved, for example, with a porous ceramic film, where water is adsorbed and transported very rapidly by the film. The carbonate or bicarbonate dried in this method is then immediately available as a fine powder, or can be very easily made into a fine powder by grinding. In this case, the average particle diameter is <1 μm. The carbonate or bicarbonate obtained in this method is immediately available in a chemically pure amorphous form. In this context, pure means that the carbonate or bicarbonate is present with a purity of >95 wt%, more preferably >98 wt%, and even more preferably >99.5 wt%.

[0342] Surprisingly, the method according to the present invention can also be used to produce carbonates using metal ions such as iron ions, aluminum ions, and copper ions, for example.

[0343] Surprisingly, aluminum carbonate could be produced by the enumerated conversion methods. This made it possible, for example, to obtain a 10% aqueous solution of aluminum chloride by dissolving aluminum chloride in a solution containing arginine at a concentration of 0.3 mol / l. This solution was slowly added to an acceptor solution saturated with carbon dioxide (2 mol / l arginine solution) in a 1:4 ratio under stirring, resulting in turbidity. After the addition of the suspension and completion of stirring, the settled whitish solid material was separated by centrifugation and then washed twice with deionized water. The paste-like material was dried by convection and then mechanically ground to obtain a whitish powder. The powder could be completely decomposed with concentrated hydrochloric acid, producing carbon dioxide and aluminum chloride solution. Surprisingly, no gas formation or heating occurred during the dissolution of the aluminum chloride salt in the acceptor solution or when the solutions were in contact.

[0344] Surprisingly, it has been revealed that when ammonium ions are simultaneously present in the solution according to the present invention in which carbonate formation is achieved, bicarbonate formation proceeds preferentially. In a preferred embodiment, ammonia is added to the solution in which carbonate / bicarbonate formation is achieved. This can be done before, during, or after contact of the solution with a water-soluble gas / gaseous component. Preferably, this embodiment of the method is carried out in the case of the acceptor solution according to the present invention. However, the addition can also be carried out in conversion methods 2 and 3, in which case the addition is carried out in the reaction chamber and / or the incorporation and emission chambers. It has been revealed that even low concentrations of ammonia in one of the solutions in which bicarbonate / carbonate conversion is performed are sufficient to allow the preferential formation of bicarbonate over carbonate to occur. The preferred ammonia concentration in the solution in which bicarbonate / carbonate formation is achieved is between 0.001 wt% and 5.0 wt%, more preferably between 0.005 wt% and 3.0 wt%, and even more preferably between 0.01 wt% and 1.5 wt%. The preferred formation of bicarbonates is due to the introduction of an anion (e.g., Cl) bonded by an ammonium ion.- or SO4 2- Since it depends on the concentration of (etc.), the optimal concentration of ammonia must be determined individually. The resulting bicarbonate is separated and purified using the same separation techniques described herein. In a preferred method embodiment, the production of bicarbonate or carbonate is carried out at a method temperature which is preferably <50°C, more preferably <35°C, even more preferably <20°C, and even more preferably <10°C. In a preferred method embodiment, separation of the ammonium salt present in the acceptor solution or reaction solution is carried out. Preferably, this can be done by electrodialysis.

[0345] It was further revealed that separating anionic or anionic compounds from an electrolyte solution containing cationic or cationic compounds suitable for the formation of carbonates or hydrocarbon salts, using reaction with ammonia, is particularly advantageous. In addition to the higher conversion rate and amount of change of cationic or cationic compounds to carbonates or bicarbonates, it was also revealed that impurities that may be present in the electrolyte solution can be removed very easily. This can be demonstrated, for example, using recycled and organic compound-containing aluminum materials (including aluminum foil). Acid hydrolysis was performed using concentrated hydrochloric acid. A gray solid with pH 1 was formed, which could be completely dissolved in water. When mixed in a 25 wt% ammonia solution, aggregation began at pH 2.5, and this increased with the addition of further ammonia solution. At pH 4, the solution was centrifuged. A dark brown solid had precipitated, as well as a white centrifugal precipitate. The supernatant was clear and had no ammonia odor at pH 4. The supernatant was added to a 2 molar concentration arginine solution saturated with carbon dioxide, and a white solid was immediately formed. Compared to experiments using a solution without added ammonia, more than three times the amount of solid could be separated from the acceptor solution. This indicates that more than twice the amount of electrolyte solution pretreated with ammonia can be separated from the acceptor solution without further formation of carbonates or bicarbonates. This is also due to the fact that it was possible to add it to the acceptor solution until the solution's pH was reached. Pure aluminum bicarbonate was identified by solid-state analysis.

[0346] It was also shown that sulfate anions can be removed from the electrolyte solution by this process, and that electrolyte solutions with fewer sulfates allow for more conversion of cationic compounds than those using sulfate or anion-rich electrolyte solutions. In another application, a regeneration solution (pH 7) in a cation exchanger used to produce deionized water was studied. Regeneration was carried out using a NaCl solution. It was shown that mixing with ammonia resulted in coagulation, and that the coagulation could be separated by centrifugation. When the clear supernatant (pH 9) was added to a carbon dioxide saturated acceptor solution, a solid was formed. A mixture of calcium bicarbonate and magnesium bicarbonate was demonstrated in solid analysis.

[0347] Preferably, the method for producing a bicarbonate involves adding ammonium ions to an electrolyte solution, and then combining the mixture and mixing it with an aqueous acceptor solution saturated with carbon dioxide or a water-soluble derivative thereof.

[0348] A preferred method for preparing carbonates and / or bicarbonates is one in which an anion or anionic compound is complexed and separated from an electrolyte solution containing a cationic or cationic compound and anion or anionic compound by ammonium ions, and the anion-low electrolyte liquid is then combined and mixed with an aqueous acceptor solution saturated with carbon dioxide or its water-soluble derivative, resulting in the spontaneous formation of carbonates and / or bicarbonates.

[0349] Therefore, in principle, carbonates and bicarbonates can be prepared from carbon dioxide or its derivatives, which exist in a reactive form in an acceptor solution, or are converted to a reactive form by an acceptor compound, or exist bound to such a reactive form, and a chemical transformation occurs when carbon dioxide or its derivative is brought into contact with an element or compound that exists as a cationic / cationic compound, i.e., in ionic form. This makes it possible to obtain carbonates (bicarbonates), and to produce, for example, sodium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, cobalt carbonate, iron carbonate, copper carbonate, aluminum carbonate, silicon carbonate, zinc carbonate, silver carbonate, lead carbonate, and ammonium carbonate, as well as the corresponding bicarbonates, in a pure amorphous form.

[0350] The preferred bicarbonates and carbonates produced by the method according to the present invention have an average particle size of preferably <2 μm, more preferably <1.5 μm, even more preferably <1 μm, and even more preferably <0.5 μm.

[0351] Preferably, the preparation involves amorphous forms of bicarbonates and carbonates. Preferably, it is a low-energy method for producing carbonates and / or bicarbonates.

[0352] Preferably, it is a method for producing carbonates and / or bicarbonates from renewable raw materials with low energy content. Preferably, the regenerated carbonate and regenerated bicarbonate are produced by the method according to the present invention.

[0353] Preferably, it is a method for producing aluminum carbonate. Preferably, it is aluminum carbonate produced by the method according to the present invention. Preferably, this is a method for preparing aluminum bicarbonate.

[0354] Preferably, it is aluminum bicarbonate produced by the method according to the present invention. Preferably, the reaction compound is aluminum carbonate prepared by the method according to the present invention, where the reaction compound is an aluminum salt, preferably aluminum chloride.

[0355] Preferably, the reaction compound is aluminum bicarbonate prepared by the method according to the present invention, where the reaction compound is an aluminum salt, preferably aluminum chloride.

[0356] Reaction compounds in the form of aluminum salts for the preparation of aluminum carbonate and / or aluminum bicarbonate are not aluminum carbonate and / or aluminum bicarbonate themselves.

[0357] The preferred pH of the acceptor solution for preparing a carbonate or bicarbonate according to one embodiment of the present invention is in the range of 7 to 13.5, more preferably 8 to 12.5, and more preferably 8.5 to 12.

[0358] Preferably, an aqueous solution of a salt of the cationic compound used to produce the carbonate / bicarbonate is prepared and added to an acceptor solution saturated with carbon dioxide. In principle, the concentration of the salt solution can be freely selected. Preferably, the pH of the acceptor solution should not be lowered to less than 4 by the addition of the salt solution, otherwise the release / generation of bound carbon dioxide will occur. In other preferred embodiments, the introduction of the dissolved salt solution is carried out under pressure. To avoid a localized decrease in pH, the introduction of the salt solution should preferably be carried out under stirring. The anion of the salt can, in principle, be freely selected. Preferably, a low molecular weight compound should be used. Preferred anions are chloride ions, hydroxyl ions, sulfate ions, and citrate ions.

[0359] By introducing a salt into the acceptor solution, the anions to be used accumulate, and the anions are electrostatically attached to the guanidino or amidino groups in the acceptor compound. Therefore, the removal of anions from the acceptor solution is favorably carried out by prior art methods. This can be done continuously, for example by electrodialysis, or discontinuously, for example, using anion exchange compounds or adsorbents / complexing agents.

[0360] Therefore, this method further addresses the production and acquisition of carbonates and bicarbonates. Accordingly, a method characterized by the following steps is preferred: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group. b) bringing a gas containing carbon dioxide into contact with the acceptor solution in step a), c) converting the carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution in step b), wherein the conversion is - Add at least one cationic compound to the acceptor solution in step b), and dissolve and mix the at least one cationic compound therein, or d2) Carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution are electrophoretically transported to an incorporation and release chamber or reaction chamber, where they are contacted and mixed with at least one cationic compound, Achieved, d) Obtaining a reaction product using carbon dioxide and / or a carbon dioxide derivative in step c), the reaction product may be obtained in the chamber in which the reaction took place, and thereafter the reaction product is separated by a separation method and dried.

[0361] Therefore, this method further addresses the production and acquisition of carbonates and bicarbonates. Accordingly, a method characterized by the following steps is preferred: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group. b) Contact the gas containing carbon dioxide with the acceptor solution in step a) until the carbon dioxide concentration in the gas reaches <100 ppm. c) Conversion of carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution from step b), wherein the conversion is - Add at least one cationic compound to the acceptor solution in step b), and dissolve and mix the at least one cationic compound therein, or d2) Carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution are electrophoretically transported to an incorporation and release chamber or reaction chamber, where they are contacted and mixed with at least one cationic compound, Achieved, d) Obtaining a reaction product using carbon dioxide and / or a carbon dioxide derivative from step c), the reaction product may be obtained in the chamber in which the reaction is taking place, and thereafter the reaction product is separated by a separation method and dried.

[0362] Therefore, the method embodiments described herein are more preferably applicable to further method types, in particular to the following: Preferably, the reaction in step c) is a chemical reaction with the reactant compound; Preferably, the method for producing a reaction solution involves dissolving the reaction compound in an aqueous solution containing an acceptor compound and / or an uptake-release compound; Preferably, the reaction in step c) is carried out in an acceptor solution obtainable from step b), and / or in an incorporation and release medium, and / or in a reaction medium; Preferably, the reaction medium comprises at least one acceptor compound; Preferably, the conversion in step c), in the acceptor solution obtainable from step b), or in the acceptor medium after transport of carbon dioxide and / or carbon dioxide derivatives from the acceptor medium in step b), is carried out by combining dissolved or undissolved reaction compounds; Preferably, the conversion in step c) takes place in the incorporation and release medium and / or in the reaction medium, during or after the transport of carbon dioxide and / or carbon dioxide derivatives from the acceptor solution obtainable from step b) to each medium; Preferably, the transport of carbon dioxide and / or carbon dioxide derivatives from the acceptor solution obtainable from step b) to the uptake and release medium and / or the reaction medium is carried out by electrophoresis; Preferably, the chemical transformation in step c) is carried out using a cationic / cationic compound that enables the formation of a carbonate or bicarbonate; Preferably, the method involves obtaining a chemically pure carbonate and / or bicarbonate in an amorphous form in step d).

[0363] Surprisingly, the present invention's methods for dissolving and transporting carbon dioxide, in conjunction with any of the conversion methods disclosed herein, clearly enable the conversion of carbon dioxide and / or carbon dioxide derivatives to methane and other hydrocarbon compounds.

[0364] In a particularly preferred embodiment, conversion method 3 is used for this purpose. In one embodiment, conversion method 3 is carried out in an electrodialysis apparatus, in which one or more chamber arrays are stacked sequentially between the cathode chamber and the anode chamber in the arrangement of acceptor chamber / reaction chamber / electrolyte chamber. Preferably, the electrolyte solution circulating through the anode chamber flows through the electrolyte chamber. Preferably, at least one compound that promotes or catalyzes electrolysis is present in the electrolyte solution. Preferably, a medium suitable for taking up and reversibly binding anions and cations is present in the reaction chamber. In one embodiment, an ionic liquid is used for this purpose. Preferably, the ionic liquid is one in which a salt compound can bind hydrogen ions (protons) in a molar ratio of > / = 1. This can be done, for example, by one or more tertiary or quaternary nitrogen compounds. In a further embodiment, a compound suitable for binding hydrogen ions (protons) is dissolved in the ionic liquid. In a further embodiment, a compound having catalytic or reaction-promoting properties is present in the ionic liquid. In a more preferred embodiment, circulation of the electrolyte solution is provided between the electrolyte chamber and the cathode chamber.

[0365] Preferably, there is an open-pore or bipolar membrane between the acceptor chamber and the reaction chamber, and a cation-selective membrane between the electrolyte chamber and the reaction chamber. This configuration demonstrates that methane is formed in the reaction chamber and spontaneously generated therefrom while DC is applied between the anode and cathode.

[0366] Advantageously, in carrying out the process according to the present invention, the hydrogen generated in the electrodialysis process can be directly made available for use in one of the reactions in the conversion methods disclosed herein during or after the process carried out in accordance with the present invention.

[0367] Therefore, the method further addresses the generation and acquisition of carbon compounds. Therefore, a method characterized by the following steps is preferred: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or amidino group; b) bringing a gas containing carbon dioxide into contact with the acceptor solution in step a), c) converting the carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution in step b), or Step b) Transport of carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution, and d2) conversion in the uptake and release medium or reaction medium. d) Obtain the reaction product using carbon dioxide and / or carbon dioxide derivatives from step c) by phase separation or electrophoretic mass separation.

[0368] Therefore, the method further addresses the recovery and production of carbon compounds. Therefore, a method characterized by the following steps is preferred: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino group and / or a free amidino group; b) Using carbon dioxide, bring the acceptor solution in step a) into contact with the gas containing carbon dioxide until saturation of the acceptor solution is achieved. c) Conversion of carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution in step b), or Step b) Transport of carbon dioxide and / or carbon dioxide derivatives contained in and bound to the acceptor solution, and d2) conversion in the uptake and release medium or reaction medium. d) Obtain the reaction product using carbon dioxide and / or carbon dioxide derivatives from step c) by phase separation or electrophoretic mass separation.

[0369] Therefore, by using an acceptor solution containing at least one dissolved acceptor compound having at least one guanidino group or amidino group, extremely advantageous effects can be obtained. In particular, highly effective and selective removal of carbon dioxide from gas / gas mixtures can be achieved at atmospheric pressure and room temperature. Carbon dioxide bound to the acceptor medium, as well as carbonate anions and / or bicarbonate ions, remain there without pressurization (at atmospheric pressure) for at least six months and can be transported in this form. Furthermore, using an acceptor medium in which carbon dioxide, as well as carbonate anions and / or bicarbonate anions are present in solution, a reaction solution can be provided that allows for the immediate chemical conversion of carbon dioxide and carbonate anions and / or bicarbonate anions. Moreover, the acceptor medium is suitable for dissolving and transporting the carboxylic acids resulting from the conversion of carbon dioxide. Furthermore, the acceptor solution can be saturated multiple times with carbon dioxide, and then these can be removed without consumption or loss of the acceptor compound.

[0370] [Definition] Acceptor media The term “acceptor medium” refers to a liquid or solvent containing at least one dissolved compound capable of binding carbon dioxide / carbon dioxide derivatives. This compound is also referred to herein as the “acceptor compound.” The acceptor compound has at least one free guanidino group and / or amidino group. The acceptor compound may also include the reaction compound and other compounds. If the liquid or solvent containing at least one dissolved compound is water, the “acceptor medium” is also referred to herein as the “aqueous acceptor medium” or “acceptor solution.” The terms “aqueous acceptor medium” and “acceptor solution” or further “aqueous acceptor solution” are used interchangeably herein.

[0371] Acceptor solution As used herein, “acceptor solution” is understood to be an aqueous medium containing at least one dissolved compound capable of binding carbon dioxide, carbon dioxide derivatives, etc. This compound is also referred to herein as “acceptor compound.” The acceptor compound has at least one free guanidino group and / or amidino group. The acceptor compound may also contain the reaction compound and other compounds.

[0372] Acceptor compound As used herein, the term "acceptor compound" refers to a compound having a free guanidino group and / or amidino group. The acceptor compound is particularly preferably arginine.

[0373] cationic group As used herein, the term "cationic group" refers to a chemical functional group that has a positive charge after proton incorporation. Therefore, "cationic group" represents a positively charged functional group. A "cationic group" is also referred to herein as a positively "charged group". Preferred compounds having a "cationic group" as described herein are preferably amino acids and / or derivatives of amino acids containing at least one guanidino group and / or amidino group.

[0374] Cationic compounds As used herein, the term "cationic compound" refers to a substance having a positive charge. , salts of alkali metals and alkaline earth metals are referred to herein as "cationic compounds". In particular, they are alkali metals and alkaline earth metals that can form carbonates and bicarbonates respectively. Preferred "cationic compounds" are inorganic and organic salts of alkali metals and alkaline earth metals, which form carbonates or bicarbonates that are substantially insoluble or poorly soluble in water. Alkali metal and alkaline earth metal carbonates or bicarbonates can be selectively obtained by adding a "cationic compound" to an aqueous acceptor solution containing bound carbon dioxide, or to an aqueous acceptor solution containing bound carbon dioxide. In addition to alkali metal salts and alkaline earth metal salts, other metal cations may be used to react with carbonate anions or bicarbonate anions as disclosed herein. Examples of preferred "cationic compounds" herein include, but are not limited to, calcium chloride, ferric chloride, and aluminum chloride. Examples can be obtained of substances having carbonates or bicarbonates such as sodium, calcium, barium, magnesium, lithium, cobalt, iron, copper, aluminum, silicon, zinc, silver, lead, for example, sodium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, cobalt carbonate, iron carbonate, copper carbonate, aluminum carbonate, silicon carbonate, zinc carbonate, silver carbonate, lead carbonate, and ammonium carbonate, as well as the corresponding bicarbonates, and aluminum carbonate or substances having bicarbonates such as aluminum bicarbonate. Salts of sodium, calcium, barium, magnesium, lithium, cobalt, iron, copper, aluminum, silicon, zinc, silver, and lead may be used herein as cationic compounds. Particularly preferred cationic compounds herein are aluminum salts such as aluminum chloride.

[0375] Carbon dioxide derivatives The term "carbon dioxide derivatives" is used herein to refer to all compounds that are formed or can be formed by the dissolution process of carbon dioxide in water. In particular, these are H2CO3, HCO3 - , CO3 2-It contains. Carbon dioxide (CO2) forms carbonic acid in water. Carbonic acid (H2CO3) is an inorganic acid and a reaction product of the acid anhydride carbon dioxide (CO2) and water.

[0376] Reacting compounds The term "reacting compound" refers to a compound that undergoes or causes a reaction with carbon dioxide and / or carbon dioxide derivatives. In this process, carbon dioxide and / or carbon dioxide derivatives chemically react and / or bond. A preferred “reacting compound” as used herein is a “cationic compound” as defined above.

[0377] Intake and release media The term “intake and release medium” means a gas, liquid, or solid that adsorbs, absorbs, physically absorbs, or binds carbon dioxide and / or carbon dioxide derivatives, or reacts with them, and / or releases / generates them. Preferably, the medium contains one or more compounds that give rise to the aforementioned properties. In this regard, the intake and release medium may also include reaction compounds, acceptor compounds, and other compounds. Preferably, in this specification, the intake and release medium is aqueous. As used herein, the term “intake and release medium” refers to a medium capable of releasing / generating bound carbon dioxide. In this regard, the release / generation of carbon dioxide may occur directly when carbon dioxide derivatives, such as carbonate anions / bicarbonate anions, enter the intake and release medium. Preferably, the release / generation of carbon dioxide from the intake and release medium occurs after the carbon dioxide has been introduced into a release device or release chamber.

[0378] Element or elemental molecule As used herein, the term "element" refers to an element whose atomic number increases in the periodic table (PTE). This refers to known chemical elements arranged in a specific order. An "elemental molecule" is a molecule consisting of only two or more atoms of a single chemical element. In contrast to elemental molecules, all other molecules consist of at least two atoms of different chemical elements (for example, carbon dioxide (CO2) made of carbon and oxygen). A "gaseous element" or "gaseous elemental molecule" is an element or elemental molecule that is a gas under normal conditions. These are the six noble gases He, Ne, Ar, Kr, Xe, and Rn, and five other elements that are gases under normal conditions: hydrogen (H2), nitrogen (N2), oxygen (O2), fluorine (F2), and chlorine (Cl2).

[0379] molecular compound The term "molecular compound" refers to a molecule of at least two different chemical elements (for example, carbon dioxide (CO2) from carbon and oxygen). The term "gaseous molecular compound," or simply "gaseous compound," refers to a molecular compound that is a gas under normal conditions. Examples of "gaseous molecular compounds" that are gases under normal conditions include, but are not limited to, carbon dioxide (CO2), methane (CH4), ammonia (NH3), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (also called nitrous oxide) (N2O), sulfur dioxide (SO2), hydrogen chloride (HCl), ethane (CH3CH3), propane (CH3CH2CH3), butane (CH3CH2CH2CH3), and acetylene (CH≡CH).

[0380] Gas / Gaseous phase As used herein, the terms “gas” or “gaseous phase” refer to the gaseous phase of an element or compound, whether as a pure substance or as a mixture. Examples of pure gases are gaseous carbon dioxide, methane, or hydrogen. Examples of gaseous mixtures are air, combustion / fumigant gas, biogas, sewage gas, or acidic natural gas. In addition to solids and liquids, gas is one of the three classical states of condensation. For some elements and compounds, standard conditions (temperature 20°C, pressure 101,325 Pa) are already sufficient for the elements and compounds to exist as gases. In this context, the term “air” refers to the gaseous mixture of the Earth’s atmosphere. Dry air consists mainly of two gaseous substances: nitrogen (approximately 78.08% by volume) and oxygen (approximately 20.95% by volume). Furthermore, the components argon (0.93 vol.%), carbon dioxide (0.04 vol.%) or 400 ppm) and other gases are present in concentrations of less than 0.002 vol.%, or in trace amounts of 20 ppm, such as neon (Ne), helium (He), methane (CH4), krypton (Kr), nitrous oxide (N2O), carbon monoxide (CO), xenon (Xe), various chlorofluorocarbons (CFCs), such as dichlorodifluoromethane, trichlorofluoromethane, chlorodifluoromethane, trichlorotrifluoroethane, 1,1-dichloro-1-fluoroethane, 1-chloro,1-1-difluoroethane, as well as carbon tetrachloride, sulfur hexafluoride, bromochlorodifluoromethane, and bromotrifluoromethane.

[0381] Water-soluble gas In the dissolution of gases into liquids, the term solubility indicates the amount of gas dissolved in a liquid at a given pressure when the gas is in diffusive equilibrium with the liquid, i.e., when the diffusion from the gas phase and the liquid is exactly the same. Solubility depends on temperature, pressure, and for some compounds, on pH. As used herein, the term “water-soluble gas” in this context means that a gaseous molecular compound reacts chemically with water to form, for example, an acid anhydride or an acid. It then exists in water as an organic or inorganic acid, or as an anion. Preferred “water-soluble gas” herein is, in particular, a gas corresponding to the term “acidic gas” which forms an acid or weak acid when dissolved in water.

[0382] The term "water-soluble gas" should be distinguished from gases that do not chemically react with water upon contact. For example, methane (CH4) has a solubility of 36.7 ml / l in water at normal pressure and 20°C. Since methane does not react with water, it is not a water-soluble gas.

[0383] Water-soluble gas The term "water-soluble gaseous component" includes all gaseous compounds that, when present in the gaseous phase and in contact with and / or mixed with water, form water-soluble compounds with water. Examples include carbon dioxide, sulfur dioxide, hydrogen sulfide, nitric oxide, nitrous oxide, hydrogen chloride, or chlorine dioxide. Therefore, "water-soluble gaseous fraction" includes "water-soluble gases," and in particular, "acidic gases."

[0384] acidic gas As used herein, the term “acidic gas” also refers to gases or mixtures of gases that, when dissolved in water, form an acid or a weak acid. Acidic gases are frequently corrosive, caustic, and toxic, and thus pose a danger to humans and the environment. Acidic gases may be naturally occurring or may be produced as desirable or undesirable reaction gases in industrial processes. Examples of acidic gases include, but are not limited to, carbon dioxide (CO2) (which forms carbonic acid and bicarbonate in water), sulfur dioxide (SO2) (which forms sulfurous acid in water), hydrogen sulfide (H2S), hydrogen chloride (HCl) (which forms hydrochloric acid in water), nitrogen dioxide (N2O) (which forms nitric acid in water), hydrogen cyanide (HCN) (which forms hydrogen cyanide in water), hydrogen bromide (HBr) (which forms hydrobromic acid in water), and selenium dioxide (SeO2) (which forms selenite in water).

[0385] Basic amino acids As used herein, the term "basic amino acid" refers to an amino acid having an amino group or an N atom with a free electron pair in its amino acid residue (side chain). When these N atoms accept a proton, they form a positively charged side chain. The amino acids histidine, lysine, and arginine belong to the category of basic amino acids. Preferably, in this specification according to the present invention, the basic amino acid is having at least one guanidino group and / or amidino group, and particularly preferably, the basic amino acid arginine.

[0386] Electrophoretic separation As used herein, the term “electrophoretic separation” refers to electrochemical separation using a separation membrane in an electrochemical process such as electrodialysis. In the electrolytic process, electrolysis takes place in an electrolytic cell. The electrolytic cell consists of two electrodes made, for example, of carbon or platinum, and a conductive liquid. The electrode connected to the anode is called the anode, and the electrode connected to the cathode is called the cathode. Cations move to the negatively charged cathode, and anions move to the positively charged anode. The “electrophoretic separation cell” used herein to achieve “electrophoretic separation” consists of at least two chambers separated by a separation membrane. The “acceptor chamber” contains an aqueous acceptor solution according to the present invention comprising at least one acceptor compound having a free guanidino group and / or amidino group. When a DC voltage is applied to the “electrophoretic separation cell”, the bound carbon dioxide / carbon dioxide derivative is transported through the separation membrane to the take-up and release medium in the “take-up and release chamber”. “Electrophoretic separation” is based on the principle of the electrodialysis process.

[0387] Electrodialysis Electrodialysis is a process for separating ions in a salt solution. The separation of the desired ions is achieved by an electric field applied across the anode and cathode, and an ion-exchange membrane, or a semipermeable ion-selective membrane. Electrodialysis is an electrochemically driven membrane process, in which the ion-exchange membrane is used in combination with a potential difference to separate ionic species from an uncharged solvent or impurities. One of the most common membrane materials is polystyrene (PS). To achieve ion selectivity, ion-exchange membranes use quaternary amines in the case of anion-selective membranes, and carboxylic acid groups or sulfuric acid groups in the case of cation-selective membranes. The surface can be modified by incorporating phosphatidyl groups. Some film types are mechanically reinforced with polyvinyl chloride (PVC), polypropylene (PP), or polyethylene terephthalate (PET).

[0388] separation medium As used herein, the term "separation medium" refers to a medium capable of achieving selective mass transfer. Therefore, as used herein, "separation medium" may also be referred to as a separation membrane or transport membrane.

[0389] Separation membrane As used herein, “separation membrane” or simply “membrane” generally refers to a thin layer of material that affects the transport of substances through the layer. In separation techniques, membranes are used as separation layers. Membranes can be permeable in various ways: impermeable, selectively permeable, unidirectionally permeable, or omnipermeable. The vast majority of commercial membranes are made from polymers. A number of different plastics are used, and the requirements vary greatly depending on the application area. The two most common forms are wound membranes and hollow fibers. Lipophilic polymer membranes can allow some gases or organic substances to pass through, but not water or aqueous solutions. However, in polymer layers, ionic groups within the polymer can also prevent ions from passing through the membrane. Such membranes are used, for example, in electrodialysis. Other membranes allow only water and certain gases to pass through. Commonly used membrane materials include: polysulfone, polyethersulfone (PES), cellulose, cellulose esters (cellulose acetate, cellulose nitrate), regenerated cellulose (RC), silicone, polyamide ("nylon," more precisely: PA6, PA6.6, PA6.10, PA6.12, PA11, PA12), polyamide-imide, polyamide-urea, polycarbonate, ceramic, stainless steel, silver, silicon, zeolite (aluminosilicate), polyacrylonitrile (PAN), polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), and polypiperazine-amide. Ceramic membranes are primarily used in areas where high chemical or thermal requirements are set on the filter.

[0390] Separation membrane for electrophoresis separation As used herein, the term "separation membrane" refers to a separation medium used in electrophoretic separation or electrolysis. Preferably, the separation membrane is an open-pore membrane, and more preferably an open-pore mesoporous membrane. In some embodiments, the separation membrane is a ceramic filter plate. In some embodiments, the separation membrane is an anion-selective membrane. Any suitable separation membrane from the prior art may be used as the separation membrane. From the prior art, ion-selective separation membranes and bipolar separation membranes are well known.

[0391] A separation membrane used to bring a gas containing carbon dioxide into contact with an acceptor medium. As used herein, the separation medium for bringing a carbon dioxide-containing gas into contact with an acceptor medium refers to a "separation membrane" suitable for mass transfer between a gaseous phase and a liquid phase. These separation media are also referred to herein as “gas-liquid separation membranes.” Contacting a carbon dioxide-containing gas with an acceptor medium is also referred to herein as “indirect contact.” The gas-liquid separation membranes may be provided in the form of membrane contactors. The membrane contactors are preferably used herein to indirectly contact a carbon dioxide-containing gas with an acceptor medium. A membrane film can also be provided as a gas-liquid separation membrane mounted on a support material. Such gas-liquid separation membranes are known from the prior art. Preferred gas-liquid separation membranes have an average pore size of >10 μm, more preferably >50 μm, more preferably >100 μm, more preferably >150 μm, and more preferably >200 μm. Gas-liquid separation membranes having an average pore size of 200 μm are particularly preferred. Preferred gas-liquid separation membranes have an average pore size of <300 μm, more preferably <20 The membrane has a film thickness of 0 μm, more preferably <150 μm, more preferably <100 μm, more preferably <50 μm, and even more preferably <25 μm. A preferred gas-liquid separation membrane has an opening channel having an average channel diameter of >10 μm, more preferably >50 μm, even more preferably >100 μm, more preferably >150 μm, even more preferably >200 μm, even more preferably >250 μm, and most preferably >300 μm. A preferred gas-liquid separation membrane has a porosity of >50%, more preferably >60%, more preferably >70%, more preferably >80%, and even more preferably >90%. Porosity is defined as the number of pores per unit area. Suitable materials for the gas-liquid separation membrane include, but are not limited to, PTFE (polytetrafluoroethylene) or PC (polycarbonate) or ceramics.

[0392] Gas scrubbing When a gas or airflow passes through a scrubbing solution, it is called gas scrubbing or absorption. In this process, the gaseous components that are absorbed (absorbed - unbound, absorbed - bound) are bound in the scrubbing solution (absorbed - unloaded, absorbed substance - loaded).

[0393] salt As used herein, the term "salt" refers to a compound composed of positively charged ions (cations) and negatively charged ions (anions). Ionic bonds exist between these ions. In "inorganic salts," cations are often formed by metals, and anions are often formed by nonmetals or nonmetallic oxides. "Organic salts" are all compounds in which at least one anion or cation is an organic compound; excluding carbonates derived from carbonic acid (H2CO3), which is inorganic by definition.

[0394] Normal conditions The terms “normal conditions” or “STP (Standard Temperature and Pressure) conditions” refer, as used herein, to “standard pressure” of 101.325 Pa = 1.01325 bar = 1 atm = 760 Torr and “standard temperature” of 293.15 K ≈ 20°C. The term “atmospheric pressure” refers to the atmospheric pressure at any point in the Earth’s atmosphere. The standard mean atmospheric pressure (“atmospheric pressure”) at sea level is 101,325 Pa = 101.325 kPa = 1013.25 hPa ≈ 1 bar. The terms “atmospheric pressure” and “standard pressure” are used interchangeably herein. As used herein, the term “unpressurized” also refers to the terms “atmospheric pressure” and “normal pressure”. Where a process step is described in this application as being performed “unpressurized,” this corresponds to a process step performed under “atmospheric pressure” and “normal pressure.” As used herein, the term “no pressurization” also refers to the terms “atmospheric pressure” and “normal pressure.” Where this application states that a process step is performed “without pressurization,” this corresponds to the process performance under “atmospheric pressure” and “normal pressure.”

[0395] Gas scrubber A gas scrubber, wet separator, or absorber is a process apparatus that brings a gas stream into contact with a liquid stream to absorb components of the gas stream in the liquid. The components of the gas stream being transported can be solid, liquid, or gaseous substances. Gas scrubbing apparatuses known in the prior art can be used to separate CO2 from flue gas or biogas. Gas scrubbing apparatuses may include pre-scrubbing gas scrubbing columns. Differences are made between fixed-bed columns, packed columns, tray columns, and spray columns.

[0396] clean gas The term "clean gas" as used herein is derived from the following classification into purity classes: Raw gas (similarly crudum, crd.) - unrefined quality. Industrial gases are used for general technical purposes, are typically produced on a large scale, and may have heterogeneous odors and colors. Synthetic gases – Since purification occurs during the formation of the synthesis product, the gases contain small amounts of impurities, which usually do not hinder the synthesis. Pure gas (purum) - Unless otherwise specified, a chemically pure quality with a substance content of >98.5% by volume. Color and property data largely correspond to relevant literature. Suitable for synthesis and experimental purposes. The purest gas (purissimum, puriss) – of exceptionally pure quality, possessing a substance content of at least >99.5 Vol%. Impurities cannot be detected by common analytical methods. Appearance and characteristic data correspond to relevant literature.

[0397] [Apply] The process is particularly suitable for selectively removing carbon dioxide components from gases or gas mixtures. Preferred gases / gas mixtures are those with a high carbon dioxide content, such as flue gas / combustion gases. Furthermore, gas mixtures produced during technical processes / synthesis or by fermentation processes such as biogas production are also suitable. This includes so-called digester gases, which are produced, for example, during the decomposition of sewage residues. In addition, the process is suitable for the purification of mineral or technically produced gases. Therefore, the process is suitable for the purification of gases / gas mixtures containing water-soluble gaseous components.

[0398] The process can be used to extract water-soluble components from gases / gas mixtures, which is achievable using this process, and can be further used to purify anaerobic gaseous phases, such as digester gas or biogas, from water-soluble gaseous components in order to obtain technically pure or the purest gas, for example, methane or biomethane. In this respect, the process can be used to produce industrial gases / gas mixtures.

[0399] This process is also suitable for hydrogen production, recovery, and conversion. The method is further suitable for extracting gaseous components from gases / gas mixtures, transporting them, storing them, and making them available. In particular, the method can be used to obtain pure gaseous carbon dioxide, which can be used in a variety of industrial applications. For example, the extracted carbon dioxide can be used as an industrial gas, as a propellant (e.g., in dispensers), for carbon dioxide concentration (e.g., in food or concrete), or for dry ice production. Thus, the method is suitable for the production of pure and most pure carbon dioxide.

[0400] In particular, the method makes it possible to obtain renewable carbon dioxide and, along with / by means of it, generate renewable products. Examples of applications include plant breeding or the creation of a renewable carbon cycle economy, by which cycle components such as synthetic fuel compounds or synthetic carbon compounds can be produced. Therefore, the method is suitable for the production of renewable carbon dioxide.

[0401] The method is even more suitable for long-term storage or transport of captured carbon dioxide. Furthermore, the method allows for the direct chemical conversion of bound carbon dioxide without further energy input, thereby directly generating and separating important starting materials for organic synthesis (production of carbon compounds) in a simple manner. Therefore, the method is suitable for the production of organic compounds.

[0402] Furthermore, carbonates and hydrocarbons can be obtained in their pure form with little technical effort. Therefore, the method is suitable for the production of carbonates and hydrocarbons. Carbonates and bicarbonates are important basic materials, for example, as fillers in building materials and the paper industry, as well as in nutritional supplements for humans and animals, and as components of tablets or toothpaste.

[0403] In particular, the method embodiments of the present invention are suitable for producing renewable and sustainable products. [Brief explanation of the drawing]

[0404] [Figure 1] Schematic diagram of apparatus for adsorption, transport, and release of water-soluble gases. In Figure 1: 1) represents any gas / gas mixture containing a water-soluble gas or gaseous component, 1a) represents the inlet apparatus for the gas / gas mixture 1) to be purified; 2) represents the gas scrubbing apparatus in which the gas 1) comes into contact with the acceptor solution; after extraction of the water-soluble gaseous component, the gas 1) exits through the outlet 3); 4) represents the collection apparatus for the acceptor solution that has come into contact with the gas 1) in the gas scrubbing apparatus 2); 5) represents the circulation circuit of the acceptor medium present between the gas scrubbing apparatus and the acceptor chamber 7) of the electrodialysis apparatus, where from 4), the acceptor solution saturated with the soluble gas is supplied to the acceptor chamber 7) through the inlet, where the acceptor solution from which the soluble gas has been removed exits from the outlet of the acceptor chamber and is supplied to the gas scrubbing apparatus 2) through the conduit; the electrodialysis apparatus is The system consists of the following individual components: 6) cathode chamber, 7) acceptor chamber, 8) intake and release chamber, 9) anode chamber, and 10) separation medium (membrane) (the ion-selective separation membrane closing the electrode chamber is not shown); 11) represents the circulation of the intake and release medium, in which, after the electrophoretically transported gas is taken in from the acceptor chamber, the intake and release medium is carried through the outlet to the release device 12), in which degassing of the intake and release medium and release of the transported gas occur, and for the release of the gas, the degassed intake and release medium is then reintroduced to chamber 8) through the inlet; the gas released in 12) can be collected in a gas collector 13) and stored in the gas collector 13). [Modes for carrying out the invention]

[0405] [Examples] Unless otherwise specified, all studies were conducted under atmospheric pressure (101.3 kPa) and room temperature (20°C) using deionized water (DI water).

[0406] [Example 1] A 0.5 molar arginine solution, prepared using deionized water, was placed in a gas washing apparatus. A constant flow rate of carbon dioxide gas was passed through the apparatus for 10 hours, and the pH of the solution was continuously determined. When the pH of the solution fell below 9, powdered arginine was added to the liquid and dissolved using a mixing unit located in the apparatus. This was repeated until a total molar concentration of arginine was present in the solution at 3 mol / l. When the pH reached 8, which was associated with the simultaneous presence of a clear liquid without any solids, the gas introduction was terminated. For long-term experiments, a portion of the solution was taken and stored in a gas-sealing apparatus at 20°C under ambient pressure conditions (101.3 kPa). Here, the amount of gas released / generated from the solutions stored for 3 months and 6 months was measured. At the end of the long-term experiments, these solutions were filled into a gas collection apparatus, HCl was added, and the mixture was mixed until a pH of 1 was achieved, as was done for the samples present after the experiment. The molar mass was determined from the determined volume of the released / generated gas and the concentration of carbon dioxide present within it, and the relationship with the molar concentration of arginine present in the solution was calculated. The experiment was repeated three times. Subsequently, the solution was subjected to electrodialysis in an electrodialysis unit. The chloride and hydrogen ions present were purified until a solution with a pH of 12.5 was obtained. These solutions were used for further repeated experiments by loading carbon dioxide into an acceptor solution until the pH of the solution reached 8. Subsequently, the amount of carbon dioxide gas bound to the solution in the three samples was measured using the procedure described above.

[0407] result: The solution's pH was 8, and the molar ratio of bound carbon dioxide to arginine in the solution ranged from 0.96 to 1.01. Between 3 and 6 months, a carbon dioxide fraction between 0.1 vol% and 0.3 vol% was released / generated. The solution remained clear throughout this period. When the experiment was repeated using an arginine solution regenerated by electrodialysis, the proportion of bound carbon dioxide remained unchanged from that in the initial experiment.

[0408] [Example 2] Flue gases containing 11.2 vol% and 16.9 vol% carbon dioxide from a cement production plant and a wood chip combined heat and power (CHP) plant were passed through a gas scrubbing column.

[0409] Before entering the scrubbing column, the flue gas was passed through a soot filter. The first section of the scrubbing column contained a 50% ammonium nitrate solution acidified to pH 5 using nitric acid as the scrubbing medium. The gas stream was then passed through an aerosol filter. The second section of the gas scrubbing column had a gas inlet device filled with arginine solution and was placed at the bottom of the chamber at 60m 2 A ceramic film with nanoporous fines having a total surface area (Kerafol, Germany) was used to discharge gas into an acceptor liquid, and flue gas was introduced through it. The average size of the released bubbles ranged from 1 μm to 20 μm.

[0410] This column consisted of 10 sequentially arranged chamber sections, in which the gaseous phase collected above the liquid surface in each chamber section was supplied via a pipe to the inlet of the gas inlet device in the next chamber section. The acceptor solution in the scrubbing column passed through the section in a countercurrent process. The purified gas mixture was collected, and the concentration of carbon dioxide was determined. Experiments were conducted at arginine concentrations between 0.1 mol / l and 0.5 mol / l, and volumetric flow rates between 100 ml / min and 1,000 ml / min. Furthermore, the volumetric flow rate of the purified flue gas was 200 cm³. 3 / minutes to 1m3 The contact time varied over a period of one minute. The contact time was calculated until the carbon dioxide concentration decreased to less than <0.01 Vol% (100 ppm). Therefore, the contact time was calculated with respect to an average bubble size of 10 μm.

[0411] result: We achieved carbon dioxide content removal to <100 ppm for both flue gas mixtures. This was possible under all experimental conditions with an average contact time between the acceptor solution and the gas mixture to be purified, depending on the selected arginine concentration and the range of 1 to 33 seconds.

[0412] [Example 3] Continuous separation of carbon dioxide from gaseous mixtures was performed using a process configuration consisting of a carbon dioxide separation unit and a carbon dioxide release unit. For this purpose, flue gas, gaseous mixtures from biogas production, and industrial gases with carbon dioxide concentrations between 3.5 vol% and 65 vol% were used. These were then subjected to a 500 cm³ process. 3 / hour to 1.5m 3 The gas was passed through the scrubbing column described in Example 2 at a flow rate of / hour. The passed gas was collected and the concentration of carbon dioxide was measured. In the acceptor solution, Arginine was present dissolved at a concentration of 0.5 mol / l (deionized water was used for dissolution). The acceptor solution, concentrated using carbon dioxide in a scrubbing column, was supplied to an electrodialysis unit consisting of 12 consecutive dialysis chamber units, each comprising an acceptor chamber and intake and release chambers. Intake was performed into the cathode chamber where the cathode was located. The acceptor fluid was passed continuously through adjacent acceptor chambers. The acceptor fluid discharged to the anode side was returned to the gas scrubbing column at the acceptor fluid inlet. Thus, circulation was established between the gas scrubbing column and the electrodialysis unit at a flow rate between 500 ml / min and 1.5 l / min. The intake and release chambers of the electrodialysis unit were interconnected, thus ensuring that the chambers containing the intake and release media were constantly filled. Above the liquid level of the intake and release media was a container for the release / emission gas, led to a large-capacity external gas container. A hydrophobically coated mesoporous ceramic separation membrane (water contact angle > 120°) was present between the cathode chamber and the acceptor chamber, and between the intake and / or release chambers. Adjacent dialysis chamber units were separated in a pressure-stable manner by an electronically conductive film (bipolar film) fixed between the acceptor chamber and the intake and release chambers. Other chamber units were arranged accordingly. The intake and release media contained either a) glutamic acid (10 g / l) or b) citric acid (100 g / l) in solution. The pH of the intake and release media was observed during electrodialysis. A DC voltage of 20 V was applied between the cathode and anode. The amount of gas released in the intake and release chambers was determined, and the gaseous compounds contained therein were analyzed.

[0413] Furthermore, the concentration of carbon dioxide present in the gas mixture passed through the gas collection device was determined. The contact time required to reduce the carbon dioxide concentration in the gas mixture passed through the gas scrubbing column to <100 ppm in each test setting was calculated. The experiments were conducted at 20°C under atmospheric pressure.

[0414] result: For all gaseous mixtures processed and investigated using the apparatus configuration, the carbon dioxide concentration could be reduced to <100 ppm. The required contact time ranged from 0.5 seconds to 2 minutes and depended heavily on the carbon dioxide concentration in the initial gaseous mixture and the flow rate of the acceptor fluid passing through the electrodialysis unit. The gas released in the intake and discharge chambers of the electrodialysis unit had a carbon dioxide content of >99 vol%. The calculated mass of carbon dioxide in the separated gaseous mixture was equal to the calculated mass of carbon dioxide removed from the initial gaseous mixture.

[0415] [Example 4] The chemical conversion properties of carbon dioxide or carbonate anions / bicarbonate anions present dissolved or bound in the acceptor medium were investigated. For this purpose, aqueous solutions containing arginine and lysine, or histidine, as acceptor compounds at concentrations from 0.1 mol / l to 0.5 mol / l were used as acceptor solutions, and the solutions were prepared using deionized water. Carbon dioxide was introduced by a gas scrubbing column according to Example 2, and flue gas with a carbon dioxide content of 22 vol% was applied for carbon dioxide extraction. As a variation of the experimental procedure in Example 2, and according to Example 1, with continuous pH recording, the acceptor compounds used were added in solid (powder) form when the pH of the acceptor solution dropped by more than 1 compared to the output due to carbon dioxide uptake. Addition was terminated when all of each 3 mol / l acceptor compound was completely dissolved and the solution became clear. The catalyst (ruthenium complex immobilized on MCM-41) was attached to a PU mesh using adhesive. These nets are attached to the acceptor chamber of the electrodialysis unit according to Example 3, and therefore these nets The medium was circumflushed with an acceptor medium flowing through the acceptor chamber. Unlike Example 3, an anion exchange membrane with a 400 Da cut-off was used as a separation membrane between the acceptor chamber and the uptake and release chambers. In this experiment, an arginine solution with a concentration of 0.3 mol / l was used as the uptake and release medium. Furthermore, as a variation from Example 3, the uptake and release medium was circulated in a second circuit, in which the medium passed through a separation device, where calcium carbonate was added to the solution and then transported to a precipitation tank, where the carboxylic acid complex and calcium complex transported to the uptake and release medium precipitated. After passing through a column containing a cation exchange resin, the solution was returned to the anode chamber. The precipitated solid was intermittently removed from the precipitation tank of the separation device, and the solid was dehydrated by centrifugation. The organic acid (white solid) bound by centrifugation was prepared by extraction with ethanol, followed by methylation, and then gas chromatography analysis.

[0416] Electrodialysis was performed by applying a 20V DC voltage between the anode and cathode while an acceptor solution containing carbon dioxide and carbonate anions / hydrocarbon anions passed through the acceptor chamber.

[0417] result: The flue gas could be purified to a carbon dioxide content of <100 ppm. Uptake and transport were carried out using an acceptor solution containing basic amino acids. The concentrations of these amino acids in the solution could be significantly increased beyond their respective solubility limits in neutral water by the uptake of carbon dioxide into the solution. This allowed for the acquisition of high concentrations of carbon dioxide and carbonate / bicarbonate anions in the aqueous acceptor solution.

[0418] Alcohol extraction from the separated calcium complex in the second circuit allowed for the detection of formic acid present in high concentrations. Thus, it could be shown that, on the one hand, carbon dioxide present in the acceptor solution and the chemical conversion of the derivative were achieved, and on the other hand, the resulting carboxylic acid was transported to the uptake and release medium by electrodialysis.

[0419] [Example 5] Research on the conversion of carbon dioxide to carbonates. A 2-mol arginine solution was prepared in 1 liter using deionized water, and 200 g each of sodium chloride (A) and calcium chloride (B) were added and dissolved. Carbon dioxide was added to the solution in a gas treatment apparatus according to Example 2. The pH of the solution was monitored. The gas application was stopped after 30 minutes, and the solution was allowed to stand for 24 hours. The supernatant was then carefully transferred, and the resulting solid was suspended in 100 ml of deionized water. The suspension was then centrifuged. The washing step was repeated two more times. The resulting centrifugal product was spread on a ceramic filter plate and dried at room temperature. The dried solid was subjected to solid-state NMR analysis. Furthermore, to detect the presence of carbonates, chemical decomposition was performed in a glass flask under a nitrogen atmosphere by adding concentrated hydrochloric acid solution to each powder (3 g). The resulting gas was passed through a CO2 analyzer. The carefully transferred supernatant was treated by electrodialysis using an anion-selective membrane.

[0420] result: The solution was initially clear. After a 2-minute gas application period, a milky, cloudy acceptor solution became apparent and continued to become rapidly cloudy. During gas application, the pH decreased from 12.4(A) and 11.8(B) to 8.6(A) and 8.3(B), respectively. After 24 hours A white solid layer settled in both reaction vessels, and the supernatant was clear in both cases. The solid was obtained as a fine white powder after drying. Carbon dioxide was released during acid-catalyzed decomposition. NMR analysis revealed sodium carbonate (A) and calcium carbonate (B), and no other elements or compounds were present. Electrodialysis of the supernatant resulted in the removal of chloride ions present therein, along with the removal of chlorine at the anode. This raised the pH of each supernatant solution to the level of each starting solution.

[0421] [Example 6] Research on the conversion of carbon dioxide to carbonates. In each case, 1 liter of a 2 molar arginine solution was prepared. These were then gas-treated with carbon dioxide for 1 hour, according to Example 2. Furthermore, 1 liter of a 1 molar arginine solution was prepared in each case, and (A) aluminum chloride or (B) ferric chloride was dissolved in each solution until the pH of the solution reached 8.

[0422] Each solution was added to one of the arginine solutions saturated with carbon dioxide under stirring. This was followed by centrifugation. The supernatant was then carefully transferred, and the resulting solid was suspended in 100 ml of deionized water. The suspension was then centrifuged. The washing process was repeated two more times. The resulting centrifuged product was dried at room temperature on a ceramic filter plate. Chemical decomposition of 2 g of each powder was carried out according to Example 5. The dried solid was decomposed at 900 °C, and the residue was subjected to elemental analysis.

[0423] result: When a solution containing aluminum or iron ions was mixed with an acceptor solution saturated with carbon dioxide, a white or rust-colored solid was formed. These could be completely separated by centrifugation, and the supernatant was clear. After washing away the soluble compounds and drying, a dry solid aggregate was obtained, which could be ground into a fine powder using a mortar and pestle. Acid-catalyzed decomposition released carbon dioxide. Pyrolysis released bound carbon dioxide. Elemental analysis could only detect aluminum(A) oxide or iron(B) oxide.

[0424] [Example 7] Investigation into the recovery of pure gases. A gas scrubbing apparatus was used, which included a packed bed into which an acceptor solution was continuously sprayed, for carbon dioxide absorption and extraction (Figure 1:2). 100m 3 A partial flow of biogas with a volumetric flow rate of / h passed through this apparatus (Figure 1:2). The packing material was exposed to a volumetric flow of acceptor solution at 100 l / min. For this purpose, acceptor solution from supply tank 1 was used (Figure 1:4). The acceptor solution used for gas scrubbing was supplied from the gas scrubbing unit to the electrodialysis unit for the desorption of carbon dioxide bound to the acceptor solution (Figure 1:5). This consisted of alternating arrangements of a cathode chamber (Figure 1:6)) and an anode chamber (Figure 1:9)), as well as chambers for receiving the acceptor solution (Figure 1:7)) and chambers for receiving the intake and release media (Figure 1:8)). The latter were separated by a bipolar membrane (Figure 1:10)), while the anode chamber was connected to the first acceptor chamber using an anion-selective membrane, and the cathode chamber was connected to the last intake and release chamber using a cation-selective membrane. The total area of ​​the bipolar membrane was 10 m². 2 That was the case.

[0425] A 2 mol / l arginine solution was selected as the acceptor solution. The acceptor solution was heated to a temperature between 34°C and 56°C during the absorption process. A 10 wt% citrate solution was used as the uptake and release medium. The acceptor medium flowing through the dialysis unit and The volume ratio between the intake medium and the cathode was 2:1. A DC voltage of 20V was applied between the anode and cathode.

[0426] The chamber apparatus for receiving the intake and release media was provided with an outlet for the gas, which was connected to a gas collector for the initially discharged gas. A storage container for the intake and release media was also connected to this collector, so that the generated gas could be collected in this collector without pressure. The gas flow through the gas scrubber and the CO2 content of the gas collected in the gas collector were continuously measured.

[0427] result The treated biogas had a CO2 content of 48 vol%. The gas that passed through the gas scrubber had a CO2 content of 0.002 vol% and a methane content of 99.1 vol%.

[0428] During continuous gas scrubbing and passage of the acceptor medium through the electrodialysis unit, CO2 was released (generated) in both the intake and release chambers, and in the storage containers for the intake and release media. The CO2 content in the released and collected gases was >98.5 vol%; methane was not detected here. Continuous operation was possible for more than 8 hours without any obstruction. There was no adequate heating of the process medium.

[0429] [Example 8] Research on the formation of carbonates. A 5-liter 2-mol arginine solution was prepared using deionized water; 500 g of iron(III) chloride was completely dissolved in this solution. Gaseous CO2 was passed through the reddish-brown clear solution according to Example 2. This reduced the pH from 9.2 to 8.5. The solution was then clear and contained no solid matter. Deionized water was then added to the solution in a 1:1 volume ratio and mixed. A cottony, light brown solid immediately formed and slowly precipitated. The supernatant, which was gently transferred, was clear and had a slightly reddish tint. The precipitated phase was centrifuged, and the supernatant was combined with the previously gently transferred supernatant (WP1). The centrifuged mixture was suspended in 3 liters of deionized water and stirred for 1 hour. Phase separation by centrifugation was then performed in each case. The brownish-reddish mass was spread on a ceramic filter plate with an average pore size of 200 μm. The filter plate was spread on the absorbent material until the material was completely dry. The easily crumbled brown material was ground in a mortar; 480 g of brown powder was obtained. The sample was suspended in water and stirred. Precipitation of the powder followed. Subsequently, the supernatant was colorless and transparent, with a pH of 6.8, and therefore did not change from the baseline. A 10% HCl solution was added to the rest of the powder sample. Foaming occurred with the release of CO2. Subsequently, the solution turned reddish-brown, and no solid remained. No nitrogen was detected in the analysis of this decomposition solution. Therefore, the obtained powder corresponds to iron carbonate. WP1 was passed through an electrodialysis apparatus. An anion-selective membrane was used to terminate the donor chamber on the anode side, and a cation-selective membrane was used to seal the cathode side. A DC voltage of 10 V was applied. Chlorine gas was released in the anode chamber, and hydrogen was released in the cathode chamber. Following electrodialysis, the solution was gaseously treated with CO2. Following the gas treatment, the CO2 bound to the solution could be released / re-generated by changing the pH using an acid (HCl).

[0430] [Example 9] Carbonate production in the secondary loop process. Partial gas flow (10m) of bioreactor in urban sewage treatment plant 3The water / gas mixture was recovered by a water jet pump device and brought into contact with an aqueous acceptor medium. The mixture was supplied to a static mixer via pipes and passed through the static mixer. The mixture then entered a collection tank, from which the gas was freely released into the atmosphere. The aqueous acceptor medium was present as a 2-mol arginine solution. From the collection tank, the carbon dioxide-loaded acceptor medium was continuously fed into the secondary circuit. The secondary circuit consisted of an electrodialysis apparatus with an anode chamber, a cathode chamber, and 10 consecutive chamber units arranged as: acceptor chamber / reaction chamber / electrolyte chamber. The acceptor chamber was continuously perforated with the acceptor medium and then supplied to a water jet pump device.

[0431] The reaction medium and electrolyte solution were removed from the storage tanks and passed through the reaction chamber and electrolyte chamber, respectively. The acceptor chamber was separated from the reaction chamber on the anode side by an anion-selective membrane. On the cathode side, the acceptor chamber was separated from the electrolyte chamber by a bipolar membrane. The reaction chamber and electrolyte chamber were separated by a cation-selective membrane. The chamber unit for the reaction medium was adjacent to the electrolyte chamber on the anode side. Different reaction mediums were investigated. For this purpose, subsequent reaction solutions were prepared from 1 molar arginine solutions in the following cases: a) 30% magnesium chloride solution, b) 20% copper chloride solution, and c) 15% aluminum chloride solution. The reaction medium was continuously recirculated in each case from the precipitation tank through the reaction chamber. The reaction chamber was designed so that the reaction medium flowed vertically through the chamber and discharged into the collection tank through a conical bottom outlet, thereby discharging any solids produced with the reaction medium. After each experiment, which was conducted for 5 hours, the reaction medium was not further stirred for 12 hours. The aqueous supernatant was then discharged through an outlet positioned above the precipitate phase, followed by removal of the precipitate, two rinses with deionized water, and then drying in a contact belt dryer.

[0432] The electrolyte solution was supplied to other electrodialysis units in the tertiary circuit, where chloride ions were separated. The detection of each carbonate obtained as a solid was performed according to the procedure of Example 6.

[0433] result: The acceptor medium temperature range was between 45°C and 75°C. The sewage gas had a carbon dioxide content of 26 vol%. By contacting the sewage gas with the acceptor medium, the carbon dioxide content decreased to <0.01 vol%. After the acceptor medium began flowing through the electrodialysis unit, the reaction solution rapidly turned milky white, and continuous precipitation of solids occurred in each case. Analysis of the rinsed and dried solids showed that the solids were carbonates of the cations of the electrolytes used in each case. Thus, magnesium carbonate, copper carbonate, and aluminum carbonate were formed.

[0434] [Example 10] Investigation into the utilization of organic and inorganic residual substances through conversion using carbon dioxide / carbon dioxide derivatives in the regeneration cycle process to obtain recycled raw material fractions. A crushed used aluminum can (100g) was completely decomposed in 200ml of concentrated sulfuric acid by adding deionized water in proportion to the amount of hydrogen and leaked water vapor. The vapor / gas mixture was collected, and the hydrogen was separated. The resulting solution was grayish-brown and very turbid. The solution was filtered using glass frit and mixed with 600ml of 1 molar arginine solution. This mixture was then mixed with a 3 molar arginine solution saturated with carbon dioxide from a gas mixture at a biogas plant. After incorporation, the suspension was centrifuged, and the centrifugated material was rinsed twice with deionized water, dried after centrifugation.

[0435] 200 g of purified chicken eggshell samples were decomposed in 500 ml of 60 wt% hydrochloric acid solution. Using the apparatus according to Example 2, the generated carbon dioxide was collected and adsorbed into a 2 molar arginine solution. Organic materials, such as eggshell membrane, were present in the resulting turbid solution. This was filtered off, and the resulting solution was passed through the electrolyte chamber of the electrodialysis apparatus according to Example 9. The acceptor chamber and reaction chamber were filled with the acceptor medium and reaction medium, respectively, and flushed with the acceptor medium and reaction medium, respectively. During this process, the acceptor solution was saturated with carbon dioxide obtained from the decomposition of the eggshells. The solid formed in the reaction chamber was separated, rinsed twice with deionized water, centrifuged, and then convectively dried. The electrolyte solution in the anode chamber was available at the end of the investigation, concentrated by membrane distillation, and used for other experimental procedures. The acceptor solution was also used for carbon dioxide absorption during bone decomposition. Energy was obtained from solar power during the investigation. The obtained solid was analyzed according to Example 6.

[0436] result: The solid fractions obtained in the two process designs were aluminum carbonate and calcium carbonate. These existed in the form of amorphous particles and chemically pure powders. The compound (acid) used to decompose the starting materials could be regenerated in the secondary circuit and reused in new test runs. The acceptor solution could also be regenerated and reused. Thus, it was possible to recycle the inorganic residues using recycled carbon dioxide and renewable energy, while enabling a sustainable cycle of the compounds used.

[0437] [Example 11] Regarding experimental procedure 1), 50 g of shredded aluminum foil is hydrolyzed with 300 ml of 35% HCl solution. Complete conversion occurs at pH 1, resulting in a light gray mass. The mass is completely dissolved in 1 liter of deionized water (1 A). From this, 150 ml is separated and titrated to pH 4 with ammonia solution under stirring. After 10 minutes, the solution is centrifuged and the supernatant is carefully transferred (1 U).

[0438] Regarding Experiment 2), 100 g of aluminum sulfate was completely dissolved in 300 ml of deionized water (2A). 150 ml of this solution was taken and titrated to pH 3 with ammonia solution under stirring. After 10 minutes, the solution was centrifuged and the supernatant was carefully transferred (1U).

[0439] A 2-mol arginine solution (prepared using deionized water) is circulated through a static mixer, and carbon dioxide is added to the solution as a gaseous phase upstream of the static mixer. The gas is applied without pressure until the acceptor solution reaches pH 8.

[0440] The chemical transformation was carried out by mixing the clear and colorless electrolyte solutions 1A, 1U, 2A, and 2U, respectively, with 1000 ml of acceptor solution using a metering pump until the pH reached 7. If the electrolyte solution could not be completely consumed / reacted during preparation, the mixing step was continued with fresh saturated acceptor solution. Fifteen minutes after mixing was complete, the reaction mixture was centrifuged. The supernatant was gently transferred and combined (V1). The centrifugated liquid obtained from each series of investigations was suspended in 1000 ml of deionized water and stirred for 15 minutes. Phase separation was then performed by centrifugation. This procedure was repeated two more times. The centrifuged material was spread onto a mesoporous ceramic membrane and left at room temperature for 24 hours immediately thereafter. The dried material was then weighed, and samples were taken for analysis and used in Example 5 and the Actual Test. This was done according to Example 6. After adding the ninhydrin reagent, the arginine concentration was determined spectroscopically.

[0441] result: A clear solution was prepared from a hydrolysate obtained from aluminum foil (Experimental Procedure 1). The addition of ammonia resulted in aggregation. The resulting solid could be completely separated by centrifugation. Centrifugal body 2 had parts of various colors: a pure white, somewhat glassy mass at the bottom and a grayish-brown solid mass above it. In Experiment 2, aggregation also occurred when ammonia was added to the electrolyte, but the centrifugal body was uniformly white and had a gel-like viscosity.

[0442] Using all electrolyte solutions, a white solid could be produced by mixing with a saturated acceptor solution. Visually, the centrifugation phases were indistinguishable from each other. To mix according to the protocol, the electrolyte solutions that were not pre-treated with ammonia required 1.6 times (Experiment 1) and 1.8 times (Experiment 2) the volume of the acceptor solution to convert the total volume of each electrolyte solution compared to those pre-treated with ammonia. On the other hand, 1A and 2A could only yield 80 wt% and 75 wt% of the solid amount that could be obtained from 1U and 2U, respectively.

[0443] Chemical analysis revealed that the obtained solids were aluminum carbonate and aluminum bicarbonate. The supernatant after the initial centrifugation was purified from the electrolytes present herein by electrodialysis. Subsequently, the volume of the liquid was reduced by membrane distillation, thus re-establishing the initial concentration of the arginine solution. This was used to reabsorb carbon dioxide and then to repeat the experimental procedure. Aluminum carbonate and aluminum bicarbonate were obtained with the same efficiency.

[0444] [Example 12] Investigation of cathode emission in the gaseous phase from aqueous acceptor media. A 2-mol arginine solution was prepared using deionized water. Two liters of this solution were separated and stored under air isolation (A0). The remaining acceptor solution was loaded with a gaseous stream of carbon dioxide according to Example 7. The degree of saturation using carbon dioxide or a water-soluble derivative of carbon dioxide was monitored by conductivity measurements. The acceptor medium was loaded with carbon dioxide until a conductivity of 150 mSi was achieved (A1).

[0445] 20 wt% solutions of KOH(K) and NaOH(N) were prepared as storage solutions. From each of these, 2 liters of a) 1 wt%, b) 2 wt%, c) 3 wt%, and d) 4 wt% solutions were prepared.

[0446] KOH(A1K) and NaOH(AlN) were added and dissolved as solids to each of 2 liters of A1, so that KOH(A1K) and NaOH(AlN) existed as a) 1 wt%, b) 2 wt%, c) 3 wt%, and d) 4 wt% solutions, respectively. A rectangular glass container capable of holding 500 ml of liquid was constructed as a separation device, so that two chambers within the container could be attached to separate them from each other. The separation device was a perforated polycarbonate disc with a diameter of 2 mm and a porosity of 70%. Graphite electrodes were placed in each chamber within a holder that allowed for axial displacement of the electrodes and were positioned parallel to the separation device. The container was airtightly sealed at the top and had outlets in the lids of each chamber. These outlets were connected to gas collectors, respectively, allowing for discharge at the low pressure formed in each chamber. Thus, the amount of each gas could be quantified.

[0447] The container had an inlet and an outlet at both front ends for filling and passing liquid. Electrodes were connected to a rectifier. The container was continuously filled with various test solutions to ensure no air remained inside. In Experiment Series 0), solutions K) and N) were filled into the container at concentrations a) to d), respectively. First, the DC voltage (Smin) at which current began to flow was determined for each solution. Then, the voltage at which bubbles formed at both electrodes was measured, thus resulting in gas formation. In Experiment Series I), solutions A0 and A1, and A1K and A1N were then continuously studied at concentrations a) to d). A constant voltage was applied to each solution for 10 minutes, and the constant voltage was at least 1 volt higher than Smin and a multiple of 2. Every 10 minutes, the voltage was increased by 2 volts up to a voltage of 32 volts. Bubble formation at the electrodes, the current present at each time (mA), and the amount of gas generated during the supply of current were recorded.

[0448] In Experimental Series II), for each solution, the test was repeated using a predetermined voltage for each solution in which gas formation did not occur at the cathode. Here, the containers containing each solution were perfusing, and thus the separation medium was taken from the cathode chamber and flowed into the anode chamber. The gases released in the cathode chamber and collected were analyzed for their chemical composition.

[0449] Results (see Tables 1a and 1b): In Experiment Series I), concentration-dependent electrolysis occurred for solutions K and N, resulting in the initiation of hydrogen and oxygen formation at voltages between 2V and 4V. For solution A0, there was no current up to 24V, and no electrolysis leading to gas phase formation up to 32V. For solution A1, a current was present starting at 12V; gas formation at the cathode began at a voltage of 20V. Gas formation at the anode did not occur even at a voltage of 32V. For solutions A1K and A1N, Smin decreased with increasing concentration. Furthermore, as a function of concentration, the voltage required for gas formation at the cathode decreased. Moreover, using these solutions, no measurable amount of oxygen was formed at the anode. The gas formed at the cathode in solutions A1, A1K, and A1N corresponded to carbon dioxide. Here, the amount of gas available in the same voltage system was considerably greater for A1K and A1N than for A1, and increased with the concentration of the added electrolyte.

[0450] In a series of experiments (II), the amount of carbon dioxide released at the cathode increased by 20 Vol% to 40 Vol% by perfusion of the container with solutions A1, A1K, and A1N.

[0451] [Table 1-1]

[0452] [Table 1-2]

[0453] [Table 2-1]

[0454] [Table 2-2]

Claims

1. A method for selectively binding, transporting, and storing carbon dioxide in an aqueous medium is characterized by the following steps: a) To provide an aqueous acceptor solution comprising at least one acceptor compound having a free guanidino and / or free amidino group. b) Bringing a gas containing carbon dioxide into contact with the acceptor solution from step a), c) Transporting the bound carbon dioxide / carbon dioxide derivative in the acceptor solution in step b) through a separation membrane to an aqueous uptake and release medium; or, Store and / or transport the acceptor solution containing the bound carbon dioxide / carbon dioxide derivative from step b).

2. The method according to claim 1, wherein the acceptor compound is an amino acid, and the pH of the acceptor solution is in the range of 8 to 13.

3. The method according to claim 1 or 2, wherein in step b), the contact is performed without pressurizing the acceptor solution.

4. The method according to any one of claims 1 to 3, wherein step b) or step c) is followed by step c1) or step d1): releasing the carbon dioxide bound in the acceptor solution as a gaseous phase.

5. The method according to any one of claims 1 to 4, wherein the acceptor solution from step b) is placed in or introduced into an acceptor chamber in an electrodialysis apparatus, and the transport of carbon dioxide / carbon dioxide derivative according to step c) is carried out by an electrical gradient established between the acceptor chamber and the intake and release chamber, wherein the acceptor chamber and the intake and release chamber are separated from each other by the separation membrane.

6. The method according to claim 5, wherein the separation membrane is a membrane that is permeable to ions and / or gas molecules.

7. The method according to claim 5, wherein the release of the carbon dioxide / carbon dioxide derivative transported through the separation membrane in the form of pure carbon dioxide gas having 98.5 vol.% carbon dioxide is carried out in the intake and release chambers.

8. The method according to any one of claims 5 to 7, wherein the intake and release chamber includes an intake and release medium comprising at least one compound having at least one acid group and an isoelectric point in the range of 3 to 5.

9. The method according to any one of claims 1 to 8, wherein one or more reaction compounds for the reaction and / or bonding of carbon dioxide and / or carbonate anions / bicarbonate anions are present in the acceptor solution and / or the incorporation and release medium.

10. The method according to any one of claims 1 to 9, wherein, after step b), the bound carbon dioxide in the acceptor solution is converted to a carbon compound by the reaction compound.

11. After step c), the bound carbon dioxide in the intake and release medium, or The method according to any one of claims 1 to 10, wherein the transported and released carbon dioxide is converted into a carbon compound by a reaction compound.

12. A method according to any one of claims 1 to 11, wherein step c) is followed by the following steps c3') and c3): c3') Introducing the aqueous uptake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c) into the release device; and c3) In the release chamber, release carbon dioxide as a gaseous phase from the intake and release medium containing the bound carbon dioxide / carbon dioxide derivative from step c3').

13. The method according to any one of claims 1 to 12, wherein carbon dioxide is cathode-separated from the aqueous acceptor solution as a pure gaseous phase.

14. The method according to any one of claims 1 to 13, wherein, prior to step b), the gas containing carbon dioxide is washed with an acidic solution.

15. The reaction compound is an aluminum salt, preferably aluminum chloride, and is an aluminum carbonate and / or aluminum bicarbonate obtained by the method according to claim 9.

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