Gas separation cell having two adsorption electrodes, with feed-side membrane

Abstract

The invention relates to an electrochemical gas separation cell (10) for separating a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture containing the Lewis acid, in particular a gas mixture. In order to provide a new type of gas separation cell (10) for separating a gaseous Lewis acid, in particular one which can be used for an electrochemical (potential) swing adsorption process or an electro(chemical) swing adsorption (ESA) process, such process being in particular quasi-continuous, the cell (10) comprises a first (20) and a second (20') adsorption electrode each having at least one electrochemically active material for the reversible electrochemical adsorption of the Lewis acid, and a separator (30) between the first (20) and second (20') adsorption electrodes, and a first membrane (60) is placed between the first adsorption electrode (20) and a first feed chamber (50) for feeding the fluid mixture. The invention also relates to such a gas separation system and to a method for operating same.

Description

[0001] R. 409539

[0002] - 1 -

[0003] Description

[0004] title

[0005] Gas separation cell with two adsorption electrodes and supply-side membrane

[0006] The present invention relates to an electrochemical gas separation cell for separating a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture containing the Lewis acid, a gas separation system therein and an operating method therefor.

[0007] State of the art

[0008] Carbon dioxide is an electrophilic electron pair acceptor and is therefore a Lewis acid.

[0009] The separation of carbon dioxide from process gas streams or atmospheric air is also known as carbon capture.

[0010] Hatton et al. describe a gas separation cell for carbon dioxide capture in the scientific publication Energy Environ, Vol. 2019, 12, 3530. This cell can be operated using electrochemical swing adsorption (ESA). The gas separation cell comprises a gas separation electrode based on para-anthraquinone-functionalized carbon nanotubes (PAQ-CNTs) and a counter electrode based on polyvinylene-ferrocene-functionalized carbon nanotubes (PVFc-CNTs). R. 409539

[0011] - 2 -

[0012] At the gas separation electrode, carbon dioxide is bound by reacting with electrons. The necessary electrical charge equalization takes place via the counter electrode, which is based on polyvinylene-ferrocene-functionalized carbon nanotubes and supplies electrons from the ferrocene. Charge equalization between the adsorption electrode and the counter electrode occurs via the ion mobility of an ionic liquid with which both electrodes are impregnated. A separator in the form of a porous membrane made of an insulating material, impregnated with the ionic liquid, is positioned between the electrodes. This separator both isolates the electron conduction between the two electrode compartments and simultaneously connects them via diffusion of the ionic liquid through its pores, thus creating an ion-conducting connection.

[0013] Publication US 2022 / 0339579 A1 describes a method for the electrochemical deposition of a gaseous Lewis acid from a fluid mixture containing the Lewis acid.

[0014] Document US 2021 / 0387139 A1 describes a gas separation cell for electrochemical (potential) swing adsorption or electro-swing adsorption (ESA).

[0015] Disclosure of the invention

[0016] The present invention relates to an electrochemical gas separation cell for the, in particular electrochemical, separation of a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture, in particular a gas mixture, containing the Lewis acid.

[0017] A Lewis acid can be understood in particular as an electrophilic electron pair acceptor, i.e., a compound to which an electron pair from an electron pair donor can attach, for example, if the compound has an empty orbital that is energetically accessible to the electron pair of the electron pair donor. R. 409539

[0018] - 3 -

[0019] The gas separation cell comprises a first adsorption electrode with at least one electrochemically active material for the reversible electrochemical adsorption of the Lewis acid, for example carbon dioxide, and a second adsorption electrode with at least one electrochemically active material for the reversible electrochemical adsorption of the Lewis acid, in particular carbon dioxide, and a separator arranged between the first adsorption electrode and the second adsorption electrode.

[0020] In particular, a first membrane is arranged between the first adsorption electrode and a first supply chamber for supplying the fluid mixture, in particular the Lewis acid, in particular the gas mixture, in particular the Lewis acid, to the first adsorption electrode.

[0021] Because the gas separation cell has a first adsorption electrode with a first membrane and a second adsorption electrode, it can advantageously be operated quasi-continuously in the sense that, during normal operation, particularly after initial preconditioning of both electrodes, one of the two electrodes is always being charged and the other discharged. At the end of each charging or discharging cycle, the operating modes of the two electrodes can then be switched.

[0022] Furthermore, this advantageously allows the conventional counter electrode, for example based on ferrocene, which serves only for charge compensation, to be omitted in favor of a second productive electrode, which can have a beneficial effect on overall efficiency. In conventional gas separation cells with conventional counter electrodes serving only for charge compensation, ideally—that is, at a current efficiency of 100%—two electrons must be transported through the cell or system, for example a stack, per Lewis acid molecule, for example, per CO2 molecule: one electron for charging and one electron for discharging. In contrast, with an R. 409539

[0023] - 4 - In the gas separation cell according to the invention, ideally only one electron per Lewis acid molecule, for example per 1 CCh molecule, needs to be transported, because each flowing electron binds (loading) one Lewis acid molecule, for example per 1 CO2 molecule, and releases (discharging) another Lewis acid molecule, for example per 1 CCh molecule. This offers a significant advantage, as it halves the ohmic losses of the overall system.

[0024] The membrane also advantageously makes it possible to equip and / or operate the cell with gas separation chambers that are spatially separated from the supply chambers, in particular via which the gaseous Lewis acid can be removed, in particular spatially separated from the fluid mixture, in particular gas mixture, for example raw gas.

[0025] The first membrane allows the cell to be equipped and / or operated with a first gas separation chamber, in particular spatially, separated from the first supply chamber of the first adsorption cell, in particular via which the gaseous Lewis acid can be discharged, in particular spatially, separately from the fluid mixture, in particular gas mixture, for example raw gas, in particular from the first adsorption electrode.

[0026] This avoids mixing the fluid mixture, especially the gas mixture, for example raw gas, and the gaseous Lewis acid, which in particular has been separated. This makes it advantageous to reduce, at least to a tolerable level, and in particular even to avoid, the evacuation and / or purging processes required to separate the gaseous Lewis acid from the raw gas in conventional gas separation cells with only a single chamber for supply and separation and / or removal, thereby reducing the energy consumption of the cell.

[0027] The membrane also advantageously prevents particle contamination of the adsorption electrode and / or the electrolyte for the electrochemical reaction of the cell, which is conventionally an ionic liquid, which is generally unavoidable in conventional gas separation cells, R. 409539

[0028] - 5 - at least to reduce or, if necessary, even to avoid. In addition, the membrane advantageously allows the feed chambers to be flushed with a suitable medium in order to remove particles introduced into the feed chambers.

[0029] Furthermore, the membrane advantageously also allows, conversely, the contamination of the fluid mixture, in particular gas mixture, for example raw gas, with the electrolyte for the electrochemical reaction of the cell, for example an ionic liquid, or the carryover of the electrolyte by the fluid mixture or gas mixture flow, which is associated with electrolyte loss and thus also loss of function of the cell, to at least reduce or possibly even avoid.

[0030] Furthermore, the membrane can advantageously prevent the electrolyte from flowing out of the cell for the electrochemical reaction, which advantageously allows the cell – in contrast to conventional gas separation cells, where gravity-induced electrolyte outflow is usually prevented by a special orientation and / or structure of the cell with respect to gravity, for example by a horizontal orientation of the cell planes – to be oriented and / or constructed differently, for example without considering the influence of gravity on this, for example with a vertical orientation of the cell planes, and thereby achieve advantageous effects.

[0031] The gas capture cell can be used particularly advantageously for carbon dioxide capture and / or for electrochemical swing adsorption (ESA).

[0032] Overall, this can provide a new type of gas capture cell for the capture of a gaseous Lewis acid, in particular for the, especially quasi-continuous, capture of, for example, carbon dioxide (carbon capture), and / or for, especially quasi-continuous, electrochemical (potential) alternating adsorption or electrochemical alternating adsorption (ESA; R. 409539).

[0033] - 6 -

[0034] Electro(chemical) Swing Adsorption) can be used and / or may exhibit the advantages described.

[0035] In one embodiment, a second membrane is arranged between the second adsorption electrode and a second feed chamber for supplying the fluid mixture, particularly the gas mixture containing the Lewis acid, to the second adsorption electrode. This advantageously increases the efficiency of the cell. For example, it can increase the yield of deposited Lewis acid.

[0036] The second membrane allows the cell to be equipped and / or operated with a second gas separation chamber, in particular spatially separated from the second supply chamber of the second adsorption cell, in particular via which the gaseous Lewis acid can be discharged, in particular spatially separated from the fluid mixture, in particular gas mixture, for example raw gas, in particular from the first adsorption electrode.

[0037] Furthermore, the advantages described in connection with the first membrane can be achieved through the second membrane.

[0038] In a further embodiment, the first membrane and / or the second membrane is permeable to the Lewis acid in a liquid and / or electrolyte-soluble state under the operating conditions of the cell, and / or the first membrane and / or the second membrane is impermeable to the Lewis acid in the gaseous state under the operating conditions of the cell.

[0039] The operating conditions of the cell can be understood in particular as the conditions under which the cell can be used and / or operated for gas separation, or is used and / or operated.

[0040] In particular, the operating conditions may include specific pressures and / or pressure ranges and / or specific pressure differentials and / or pressure differential ranges during cell operation. Other parameters may also be included in the operating conditions, R. 409539.

[0041] - 7 - for example, certain temperatures and / or temperature ranges and / or liquid and / or electrolyte levels, for example, the presence of, for example, in the case of impregnation with, liquid and / or electrolyte, et cetera during the operation of the cell.

[0042] Under the operating conditions of the cell, the first and / or second membrane can, for example, prevent the passage of gases or gaseous substances, such as the fluid mixture, the gas mixture, in particular the gaseous Lewis acid, and / or be impermeable to gases or gaseous substances, such as the fluid mixture, the gas mixture, in particular the Lewis acid in the gaseous state, and also to other gases, for example, be gas-impermeable.

[0043] In particular, the first membrane and / or the second membrane can be permeable to the Lewis acid in a liquid and / or electrolyte solution and impermeable to the Lewis acid in a gaseous state under the cell's operating conditions. Thus, the first membrane and / or the second membrane can also be described as a semipermeable and / or selective membrane, specifically permeable to the Lewis acid in a liquid and / or electrolyte solution and impermeable to the Lewis acid in a gaseous state under the cell's operating conditions.

[0044] For example, under the operating conditions of the cell, the first membrane and / or the second membrane may be permeable to the Lewis acid in a liquid and / or electrolyte-soluble state and impermeable to the Lewis acid in the gaseous state - and, for example, also to other gaseous substances, such as those in the fluid mixture or the gas mixture.

[0045] In a further embodiment, the first membrane and / or the second membrane is porous, in particular open-porous. In particular, both the first membrane and the second membrane can be porous, in particular open-porous. R. 409539

[0046] - 8 -

[0047] In a further embodiment, the first membrane and / or the second membrane is impregnated with liquid and / or electrolyte under the operating conditions of the cell. In particular, the pores of the first membrane and / or the second membrane can be filled and / or impregnated with a liquid and / or an electrolyte. Specifically, both the first membrane and the second membrane can be impregnated with liquid and / or electrolyte under the operating conditions of the cell.

[0048] In a further embodiment, the first membrane and / or the second membrane is a porous, liquid- and / or electrolyte-impregnated membrane under the operating conditions of the cell. In particular, under the operating conditions of the cell, the first membrane and the second membrane can both be porous, liquid- and / or electrolyte-impregnated membranes.

[0049] Advantageously, such a membrane or such membranes allow Lewis acid to diffuse through in a liquid and / or electrolyte solution while preventing the passage of gaseous substances, for example, of the fluid mixture, particularly of the gas mixture, such as gaseous Lewis acid. In particular, the first and second membranes can be permeable to Lewis acid in a liquid and / or electrolyte solution and impermeable to gaseous substances, for example, of the fluid mixture, particularly of the gas mixture, such as gaseous Lewis acid, and especially also to other gaseous components of the fluid mixture, particularly of the gas mixture.

[0050] The first membrane and / or the second membrane can each be designed, for example, with a narrow pore structure, such that under the operating conditions of the cell, for example, also under the pressures and / or pressure differences expected and / or occurring under the operating conditions of the cell, liquid and / or electrolyte is retained in the pores of the membrane, for example by capillary forces. R. 409539

[0051] - 9 -

[0052] For example, the first membrane, or the first and second membranes, can be designed to have a specific capillary inlet pressure that is greater than the pressures and / or pressure differences expected and / or occurring under the cell's operating conditions. Capillary inlet pressure is also used, for instance, in process engineering for dehumidifying filter cakes, where a certain gas pressure is required to at least partially dehumidify a liquid-saturated filter cake. No gas enters the filter cake if the capillary inlet pressure is not reached, as capillary forces retain the liquid within the filter cake.

[0053] For example, it is possible to equip the cell, for instance directly during its assembly or manufacturing, with a porous, liquid- and / or electrolyte-impregnated first membrane and, optionally, with a porous, liquid- and / or electrolyte-impregnated second membrane. This advantageously allows for the provision of a cell that is ready for immediate use.In combination with a suitable design of the first membrane and, if applicable, the optional second membrane with a sufficiently high capillary inlet pressure for the cell's operating conditions, a directly operational cell can thus be advantageously provided which, under the cell's operating conditions – particularly insofar as the capillary inlet pressure is not exceeded – is permeable to the Lewis acid in a liquid and / or electrolyte-soluble state and impermeable to the Lewis acid in the gaseous state – and, for example, also to other gaseous substances, such as those of the fluid mixture, particularly the gas mixture – for example, is gas-impermeable.

[0054] However, it is also possible to initially equip the cell during its construction or manufacture with only a porous first membrane, for example, a dry porous first membrane, and optionally with a second porous membrane, for example, a dry porous second membrane. The first porous membrane (e.g., dry) and the optional second porous membrane (e.g., dry) can initially be gas-permeable. R. 409539

[0055] - 10 - be. Only later, for example, at a location designated for cell operation, can the initially dry, porous first membrane and, if applicable, the optional, initially dry, porous second membrane, in particular its pores, be impregnated with liquid and / or electrolyte. In combination with a suitable design of the first membrane and, if applicable, the optional second membrane with a sufficiently high capillary inlet pressure for the cell's operating conditions, the cell can thus advantageously be made ready for operation only after its manufacture, for example, after transport to a location designated for cell operation, by introducing liquid and / or electrolyte, and the initially dry and gas-permeable porous first or second membrane be transformed into a liquid- and / or electrolyte-impregnated membrane.which is then, under the operating conditions of the cell – in particular insofar as the capillary inlet pressure is not exceeded – permeable to the Lewis acid in a liquid and / or electrolyte-soluble state and impermeable to the Lewis acid in the gaseous state – and, for example, also to other gaseous substances, for example of the fluid mixture, in particular of the gas mixture – for example, gas-impermeable.

[0056] In particular, the first membrane and / or the second membrane can be impregnated with at least one liquid electrolyte and / or at least one ionic liquid. The at least one liquid electrolyte and / or the at least one ionic liquid can, for example, be at least partially similar to, or possibly identical with, an electrolyte used for the electrochemical reaction of the cell, for example in the adsorption electrode, such as an ionic liquid and / or liquid electrolyte. In particular, the porosity of the membrane can be set so fine that the capillary inlet pressure of the electrolyte used for the electrochemical reaction of the cell, for example in the adsorption electrode, is significantly higher than the expected pressure differences between the supply chamber and the gas separation chamber.

[0057] In a further embodiment, on the side of the first membrane facing away from the first membrane and / or facing the separator, R. 409539

[0058] - 11 -

[0059] The first gas separation chamber is formed on the adsorption electrode, and / or a second gas separation chamber is formed on the side of the second adsorption electrode facing away from the second membrane and / or facing the separator. The first and / or second gas separation chamber can, in particular, also be designed for the removal of the gaseous Lewis acid. Specifically, the first and / or second gas separation chamber can be designed to remove the gaseous Lewis acid, in particular spatially, separately from the fluid mixture, in particular gas mixture, for example, raw gas.

[0060] The separator can be, in particular, ion-conducting and electrically insulating. Thus, the separator can electrically isolate the adsorption electrode from the counter electrode, or prevent electron conduction between the electrodes, and simultaneously connect the adsorption electrode and the counter electrode ionically through its ion-conducting property.

[0061] In another embodiment, the separator is arranged between the first gas separation chamber and the second gas separation chamber.

[0062] In one embodiment, the separator separates the first gas separation chamber from the second gas separation chamber and / or is impermeable to the Lewis acid in the gaseous state. Thus, in addition to its ion-conducting and electrically insulating functions, the separator can also have the secondary function of minimizing diffusive mass transport of the Lewis acid, for example carbon dioxide, between the two electrodes.

[0063] In another embodiment, the first gas separation chamber and the second gas separation chamber are connected to each other by at least one gas passage opening in the separator. This allows for a reduction in the cross-sectional area and / or the installation space by sharing the gas separation channels. R. 409539

[0064] - 12 -

[0065] In a further embodiment, the first gas separation chamber and / or the second gas separation chamber are at least partially formed by means of the separator. For this purpose, the separator can be structured in particular.

[0066] In one embodiment of this design, the separator has corrugations and / or a wave-like shape and / or a wave-like cross-section to at least partially form the first gas separation chamber and / or the second gas separation chamber. For example, the separator can be corrugated sheet-like. The gas separation chamber can be at least partially formed by cavities on the side of the adsorption electrodes.

[0067] In another, alternative, or additional embodiment of this design, gas separation channels are formed in the separator, in particular extending in a direction parallel to the plane of the separator. The gas separation channels of the separator can be located, for example, on the outer surface of the separator facing the first adsorption electrode and / or on the outer surface of the separator facing the second adsorption electrode and / or in an interior region of the separator. For example, the gas separation channels of the separator can be labyrinthine. In the case of gas separation channels located on the outer surface of the separator facing the first or second adsorption electrode, gaseous Lewis acid can be separated and, in particular, discharged from the adsorption electrode side.In the case of gas separation channels formed in an interior area of ​​the separator, gaseous Lewis acid can be separated and, in particular, removed by the separator.

[0068] In another, alternative, or additional embodiment of this design, gas passage openings are formed in the separator, in particular extending in a direction perpendicular to the plane of the separator, and especially through the separator. These gas passage openings can, for example, connect the first gas separation chamber and the second gas separation chamber. R. 409539

[0069] - 13 -

[0070] In a further embodiment, the first gas separation chamber is at least partially formed by means of the first adsorption electrode and / or the second gas separation chamber is at least partially formed by means of the second adsorption electrode. For this purpose, the first adsorption electrode and / or the second adsorption electrode can be structured in particular.

[0071] In one embodiment of this device, gas separation channels are formed in the first adsorption electrode and / or the second adsorption electrode, in particular extending in a direction parallel to the plane of the adsorption electrode. For example, the gas separation channels of the first adsorption electrode can be located on the side of the first adsorption electrode facing the separator, and / or the gas separation channels of the second adsorption electrode can be located on the side of the second adsorption electrode facing the separator. For example, the gas separation channels of the first adsorption electrode and / or the second adsorption electrode can be concave and / or have a concave cross-section and / or be grooved. Optionally, the gas separation channels of the first adsorption electrode and / or the second adsorption electrode can also be labyrinthine.

[0072] In a further embodiment, the first gas separation chamber is at least partially formed by first spacers arranged between the first adsorption electrode and the separator, in particular for distancing the separator from the first adsorption electrode, and / or the second gas separation chamber is at least partially formed by second spacers arranged between the second adsorption electrode and the separator, in particular for distancing the separator from the second adsorption electrode. For example, the first spacers can be arranged and / or formed in the gas separation channels of the first adsorption electrode and / or the second spacers in the gas separation channels of the second adsorption electrode. R. 409539

[0073] - 14 -

[0074] In another embodiment, the first and / or second spacers are formed on the separator or integrally with the separator and / or are part of the separator.

[0075] In a further embodiment, the gas separation cell has a horizontal or horizontal structure. In this configuration, the first adsorption electrodes and / or the second adsorption electrodes and / or the separator and / or the first feed chamber and / or the second feed chamber and / or the first membrane and / or the second gas separation chamber and / or the gas separation channels and / or the bipolar plate, which will be explained in more detail later, can have a substantially horizontal or horizontal extent or form horizontal or horizontal planes, in particular planes that are substantially parallel to each other.

[0076] As already explained, the first and / or second membrane also enables other advantageous cell structures.

[0077] In another embodiment, the gas separation cell has a vertical or perpendicular structure. In this configuration, the first adsorption electrode and / or the second adsorption electrode and / or the separator and / or the first feed chamber and / or the second feed chamber and / or the first membrane and / or the second gas separation chamber and / or the gas separation channels and / or the bipolar plate, which will be explained in more detail later, can have a substantially vertical or perpendicular extent or form vertical or perpendicular planes, particularly planes that are substantially parallel to each other. This can promote and / or accelerate the separation of the gaseous Lewis acid by the gas separation chamber, since the gaseous Lewis acid can escape upwards due to its vertical extent.

[0078] In a further embodiment, the first gas separation chamber and / or the second gas separation chamber O'each) is equipped with at least one R. 409539

[0079] - 15 -

[0080] Liquid electrolytes and / or fillable with at least one ionic liquid and / or filled with it. In this way, ion conduction between the electrodes through the gas separation chambers can be ensured. The gaseous Lewis acid released from the electrode in release mode can form bubbles in the at least one liquid electrolyte and / or in the at least one ionic liquid in the gas separation chamber, which can rise through the at least one liquid electrolyte and / or the at least one ionic liquid, in particular upwards.

[0081] In one embodiment of this system, the first gas separation chamber and / or the second gas separation chamber (each) are configured such that the at least one liquid electrolyte and / or the at least one ionic liquid can be circulated or are circulated. In particular, the at least one liquid electrolyte and / or the at least one ionic liquid can be circulated or moved in a closed loop, for example, by convection. This allows for improved mixing and, consequently, improved diffusive mass transport of the gas to be separated, for example, carbon dioxide, and thus an increase in the charging and discharging rates, and therefore in the performance of the cell or system.

[0082] The vertical structure of the cell can be particularly advantageous in this regard.

[0083] The at least one electrochemically active material of the adsorption electrode can be capable, in at least one reduced state, of binding and / or adsorbing the Lewis acid, for example, carbon dioxide, and releasing it again by oxidation to an oxidized state. Charges formed during the binding and / or adsorption of the Lewis acid can be balanced, in particular, by the counter electrode. For example, the at least one electrochemically active material of the adsorption electrode can comprise or be at least one para-anthraquinone-functionalized carbon material, for example, para-anthraquinone-functionalized carbon nanotubes (PAQ-CNTs). R. 409539

[0084] - 16 -

[0085] In addition to at least one electrochemically active material, the adsorption electrode may in particular comprise at least one electrolyte, for example at least one liquid electrolyte and / or at least one ionic liquid.

[0086] As part of the training process, gas bubble-promoting nucleation structures, such as boiling-stone-like structures, are introduced or formed in the adsorption electrode. This accelerates the deposition of gaseous Lewis acid.

[0087] In a further embodiment, the Lewis acid, particularly in its gaseous form, is carbon dioxide (CO2), carbonyl sulfide (COS), a sulfur oxide such as sulfur dioxide (SO2) or sulfur trioxide (SO3), a sulfuric acid ester, for example with the general chemical formula R2SO4, for example dimethyl sulfate, a nitrogen oxide such as nitrogen dioxide (NO2) or nitrogen trioxide (NO3), a phosphoric acid ester, for example with the general chemical formula: R3PO4, for example trimethyl phosphate, a sulfide, for example with the general chemical formula R2S, a carboxylic acid ester, for example with the general chemical formula: RCOOR', such as methyl formate or methyl acrylic, an aldehyde, for example with the general chemical formula: RCHO, such as formaldehyde or acrolein, a ketone, for example with the general chemical formula: R'2CO, such as acetone, an isocyanate, for example with the general chemical formula: R'NCO,such as methyl isocyanate, an isothiocyanate, for example with the general chemical formula: R'NCS, a borane, for example with the general chemical formula: BR"3, such as trimethylborane, or a borate, for example with the general chemical formula: R'sBOs, such as trimethylborate, or a combination thereof. Here, R, in particular each R independently, can represent a hydrogen atom, an alkyl group, in particular with 1 to 12 carbon atoms, a cycloalkyl group, in particular with 3 to 12 carbon atoms, a heterocycloalkyl group, in particular with 1 to 12 carbon atoms, an aryl group, in particular with 6 to 20 carbon atoms, or a heteroaryl group, in particular with 1 to 12 carbon atoms. R', R. 409539,

[0088] - 17 - in particular each R' independently of one another, can represent an alkyl group, in particular with 1 to 12 carbon atoms, a cycloalkyl group, in particular with 3 to 12 carbon atoms, a heterocycloalkyl group, in particular with 1 to 12 carbon atoms, an aryl group, in particular with 6 to 20 carbon atoms, or a heteroaryl group, in particular with 1 to 12 carbon atoms. R", in particular each R" independently of one another, can represent a hydrogen atom, a halogen atom, an alkyl group, in particular with 1 to 12 carbon atoms, a cycloalkyl group, in particular with 3 to 12 carbon atoms, a heterocycloalkyl group, in particular with 1 to 12 carbon atoms, an aryl group, in particular with 6 to 20 carbon atoms, or a heteroaryl group, in particular with 1 to 12 carbon atoms.

[0089] In one embodiment of this design, the Lewis acid, in particular gaseous, is carbon dioxide (CO2), carbonyl sulfide (COS), sulfur dioxide (SO2), sulfur trioxide (SO3), nitrogen dioxide (NO2) or nitrogen trioxide (NO3) or a combination thereof.

[0090] In a preferred embodiment of this system, the Lewis acid, particularly in its gaseous form, is carbon dioxide (CO2). The gas capture cell can be used particularly advantageously for carbon dioxide capture.

[0091] In particular, the gas separation cell can be designed for the separation of carbon dioxide and / or the adsorption electrode can be designed for the reversible electrochemical adsorption of carbon dioxide and / or the at least one electrochemically active material of the adsorption electrode can be capable of binding and / or adsorbing carbon dioxide in at least one reduced state and releasing it again by oxidation to an oxidized state and / or the at least one electrochemically active material of the adsorption electrode can have carboxylic acid groups in at least one reduced, carbon dioxide-binding state.

[0092] Regarding further technical features and advantages of the gas separation cell according to the invention, explicit reference is made to the explanations in R. 409539.

[0093] - 18 -

[0094] Reference is made to the gas separation system and the operating method according to the invention, as well as to the figure and the figure description.

[0095] Another object of the invention is an electrochemical gas separation system for the, in particular electrochemical, separation of a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture containing the Lewis acid, in particular a gas mixture, which comprises at least two gas separation cells according to the invention, for example a plurality of gas separation cells according to the invention.

[0096] In one embodiment, a bipolar plate is arranged between each pair of adjacent gas separation cells, particularly for electrically conductive connection and / or for ionic insulating separation and / or for spatial separation of adjacent gas separation cells. In particular, a bipolar plate can be arranged between the first membrane of a gas separation cell and the second adsorption electrode and / or the second membrane, especially the second membrane, of an adjacent gas separation cell.

[0097] In a further embodiment, the first feed chamber and / or the second feed chamber (O'each) are at least partially formed by means of the bipolar plate. For example, a feed chamber, in particular the first, of a gas separation cell can be at least partially formed by means of a bipolar plate, by means of which a feed chamber, in particular the second, of an adjacent cell is also at least partially formed. In particular, the feed chamber, in particular the first, of a cell and the feed chamber, in particular the second, of an adjacent cell can be formed by means of a bipolar plate. For this purpose, the bipolar plate(s) can, for example, be structured.

[0098] In one embodiment of this design, the bipolar plate(s) have beads and / or R. 409539 to form at least a partial supply chamber, in particular the first and / or second.

[0099] - 19 - a wave-like shape and / or a wave-like cross-section. For example, the bipolar plate(s) can be corrugated. For example, the first feed chamber and, in particular, the second feed chamber can be formed by the corrugations and / or the wave-like shape and / or the wave-like cross-section of the bipolar plate. The first feed chamber can, for example, be formed at least partially by cavities on the side of the bipolar plate facing the first adsorption electrode. The second feed chamber can, for example, be formed at least partially by cavities on the side of the bipolar plate facing the second adsorption electrode.

[0100] In another, alternative, or additional embodiment of this design, feed channels are formed in the bipolar plate(s), in particular extending in a direction parallel to the plane of the bipolar plate. The feed channels can be located, for example, on the side of the bipolar plate(s) facing the first adsorption electrode and / or on the side of the bipolar plate(s) facing the second adsorption electrode. For example, the feed channels of the bipolar plate(s) can be configured in a labyrinthine manner.

[0101] In one embodiment, the bipolar plate(s) separate the first supply chamber from the second supply chamber and / or the bipolar plate(s) are impermeable to the fluid mixture, in particular the gas mixture, for example the raw gas. Thus, in addition to its electrical connection function and / or ionic insulation function and / or space separation function, the bipolar plate can also have the secondary function of minimizing the mixing of different fluid / gas mixture flows (or raw gas flows).

[0102] In another embodiment, the first supply chamber and the second supply chamber are connected to each other by at least one through-hole in the bipolar plate(s), and / or the bipolar plate(s) is / are designed as an open structure. This is possible with two adsorption electrodes, optionally also with two membranes, R. 409539

[0103] - 20 - Bifunctionally designed cells enable the mixing of different fluid / gas mixture flows (or raw gas flows). Such mixing can be advantageous because the bifunctional design eliminates the need for temporarily passive channels (during regeneration of the associated electrode). Furthermore, sharing the supply channels can advantageously reduce the cross-sectional area and / or the installation space.

[0104] In a further embodiment, the first feed chamber is at least partially formed by means of a gas-conducting, in particular gas-conducting and electrically conductive, intermediate layer between the first membrane and an adjacent bipolar plate, and / or the second feed chamber is at least partially formed by means of a gas-conducting, in particular gas-conducting and electrically conductive, intermediate layer between the second adsorption electrode and / or the second membrane, in particular the second membrane, and an adjacent bipolar plate. This embodiment allows the bipolar plate(s) to be made flat. This advantageously reduces manufacturing costs. The intermediate layer can, for example, be expanded metal, a metallic fabric, a metallic nonwoven, or be porous and / or gas-conducting and, in particular, electrically conductive, i.e., electron-conducting, in another form.

[0105] In one embodiment of this design, the intermediate layer is porous.

[0106] In another, alternative, or additional embodiment of this design, feed channels are formed in the intermediate layer, in particular those extending in a direction parallel to the plane of the intermediate layer. For example, the feed channels of the intermediate layer can be labyrinthine.

[0107] In another embodiment, the gas separation cells are arranged in a stack. R. 409539

[0108] - 21 -

[0109] In one embodiment of this design, the gas separation cells are arranged in the form of a horizontal stack or a stack with horizontal planes.

[0110] In another preferred embodiment of this design, the gas separation cells are arranged in the form of a vertical stack or a stack with vertical planes. This allows the separation of the gaseous Lewis acid by the gas separation chamber to be promoted and / or accelerated, since the gaseous Lewis acid can escape through its vertical extension.

[0111] In a further embodiment, the first membrane and / or the second membrane is at least partially, and optionally completely, electrically conductive, i.e., electron-conducting. For example, the first membrane and / or the second membrane can comprise electrically conductive particles. In this way, the adsorption electrodes can be electrically connected to a bipolar plate via the respective membrane.

[0112] In another embodiment, the bipolar plate has contact points that penetrate the first membrane and / or the second membrane. This allows the adsorption electrodes to be electrically connected to the bipolar plate through the respective membrane.

[0113] In a further embodiment, the first membrane comprises through-holes through which the bipolar plate extends partially to the first adsorption electrode, and / or the second membrane comprises through-holes through which the bipolar plate extends partially to the second adsorption electrode. These through-holes can be formed in the first and / or second membrane before assembly or created during assembly by piercing, for example, points, into the bipolar plate. The bipolar plate can, in particular, close and / or seal the through-holes. For example, the grooves of the bipolar plate can extend partially through the through-holes, thereby closing and / or sealing them, particularly through high surface pressures. R. 409539

[0114] - 22 -

[0115] In this way, the adsorption electrodes can be electrically connected to a bipolar plate through the recesses in the respective membrane.

[0116] In a further embodiment, the first adsorption electrode and / or the second adsorption electrode, for example secondary ones, have metallic structures for electrically contacting the bipolar plate. In this way, the adsorption electrodes can be electrically connected to a bipolar plate via these metallic structures.

[0117] The gas separation system and / or the gas separation cell according to the invention can be used, for example, to clean exhaust gas of Lewis acid, in particular carbon dioxide, especially from a ship or, for example, a locomotive or other vehicle with sufficient installation space for this purpose, or from a stationary plant, for example, a heating system and / or a fuel cell system and / or a generator and / or a heat engine and / or an industrial plant and / or a chemical plant, for example, in which carbon dioxide is produced as a by-product, for example, during the burning of lime in cement production (CaCOa CaO + CO2), and / or for carbon dioxide capture from air (DAC; English: Direct Air Capture).

[0118] With regard to further technical features and advantages of the gas separation system according to the invention, explicit reference is hereby made to the explanations in connection with the gas separation cell according to the invention and the operating method according to the invention, as well as to the figure and the figure description.

[0119] Furthermore, the invention relates to a method for operating a gas separation cell and / or a gas separation system according to the invention for the, in particular electrochemical, separation of a gaseous Lewis acid, especially carbon dioxide, from a fluid mixture, in particular a gas mixture, containing the Lewis acid. R. 409539

[0120] - 23 -

[0121] In this process, the gas separation cell or cells are operated in particular by means of electrochemical (potential) swing adsorption or electro-swing adsorption (ESA), in particular quasi-continuously.

[0122] In one embodiment, during a first adsorption and gas release operation of the gas separation cell(s), the fluid mixture, in particular a gas mixture, containing the Lewis acid is passed through the first feed chamber over the first membrane. The Lewis acid can dissolve, or be dissolved, in the first membrane, particularly in the liquid and / or electrolyte of the first membrane. In the liquid and / or electrolyte-soluble state, the Lewis acid can diffuse through the first membrane to the first adsorption electrode.In the first adsorption and gas release operation, a potential or voltage is set between the first adsorption electrode and the second adsorption electrode of the cell such that the at least one electrochemically active material of the first adsorption electrode is reduced by absorbing electrons and by binding and / or adsorption of the Lewis acid, and the at least one electrochemically active material of the second adsorption electrode is oxidized by releasing electrons and by releasing the gaseous Lewis acid, in particular into the second gas separation chamber.

[0123] The gas separation cell can, for example, be operated in the first adsorption and gas release operation up to a certain saturation, for example up to complete saturation, of the at least one electrochemically active material of the first adsorption electrode with the Lewis acid and / or up to a certain degree of desorption, for example up to complete desorption, of the at least one electrochemically active material of the second adsorption electrode by the Lewis acid.

[0124] After reaching the specified saturation and / or a specific degree of desorption in the first adsorption and gas release operation, R. 409539

[0125] - 24 -

[0126] The gas separation cell can then be switched to and / or operated in a second adsorption and gas release mode.

[0127] In a further embodiment, during the second adsorption and gas release operation of the gas separation cell(s), the fluid mixture, particularly a gas mixture, containing the Lewis acid is passed through the second feed chamber over the second adsorption electrode and / or over the second membrane. The Lewis acid can dissolve, or become dissolved, particularly in the second adsorption electrode and / or in the second membrane, for example, in the liquid and / or electrolyte. In the liquid and / or electrolyte-soluble state, the Lewis acid can diffuse through the second adsorption electrode and / or through the second membrane, particularly through the second membrane to the second adsorption electrode.In the second adsorption and gas release operation, the potential (or voltage) between the first and second adsorption electrodes of the cell is reversed, particularly compared to the first adsorption and gas release operation. This reverses the polarity such that the at least one electrochemically active material of the second adsorption electrode is reduced by accepting electrons and binding and / or adsorbing the Lewis acid, while the at least one electrochemically active material of the first adsorption electrode is oxidized by releasing electrons and releasing the gaseous Lewis acid, particularly into the first gas separation chamber. With identical designs of the first and second adsorption electrodes, this can be achieved by reversing the polarity and changing the sign.With extremely different designs of the first and second adsorption electrodes, the current can reverse even without a change in voltage sign. R. 409539.

[0128] - 25 -

[0129] The gaseous Lewis acid released in the first and / or second adsorption and gas release operation, in particular carbon dioxide, can be separated or captured.

[0130] The gas separation cell can, for example, be operated in the second adsorption and gas release operation up to a certain saturation, for example up to complete saturation, of the at least one electrochemically active material of the second adsorption electrode with the Lewis acid and / or up to a certain degree of desorption, for example up to complete desorption, of the at least one electrochemically active material of the first adsorption electrode by the Lewis acid.

[0131] After reaching a certain saturation and / or a certain degree of desorption in the second adsorption and gas release operation, the gas separation cell can then be switched to and / or operated in a first adsorption and gas release operation.

[0132] The operating process can be carried out in cycles, with each cycle comprising a first adsorption and gas release phase and a second adsorption and gas release phase. The Lewis acid can be separated, in particular, by repeatedly performing these cycles.

[0133] During operation of the gas separation cell(s), the pressure in the supply chambers and in the gas separation chambers may be at different levels.

[0134] In a further embodiment, during the first adsorption and gas release operation of the gas separation cell(s), the pressure in the second gas separation chamber is reduced, and / or during the second adsorption and gas release operation of the gas separation cell(s), the pressure in the first gas separation chamber is reduced. This advantageously promotes and / or accelerates the release of the Lewis acid. R. 409539

[0135] - 26 -

[0136] In a further embodiment, during the first adsorption and gas release operation of the gas separation cell(s), the pressure in the first gas separation chamber is increased, and / or during the second adsorption and gas release operation of the gas separation cell(s), the pressure in the second gas separation chamber is increased. This advantageously promotes and / or accelerates the dissolution of the Lewis acid in the membrane, particularly in the liquid and / or electrolyte of the membrane.

[0137] In a further embodiment, before the first adsorption and gas release operation and / or before the second adsorption and gas release operation, for example, between the first and second adsorption and gas release operations and / or between the second and first adsorption and gas release operations, the first and / or second feed chamber of the gas separation cell(s) is partially or completely evacuated. Partial evacuation can be understood, in particular, as a reduction in pressure to an average pressure level, for example, to approximately 500 mbar, and / or merely as the evacuation of certain channels of the system.This advantageously prevents the potential dissolution of other gases from the fluid mixture, particularly gas mixtures, besides the Lewis acid to be deposited, into the membrane, especially into the liquid and / or electrolyte of the membrane, without affecting or removing the Lewis acid bound to the at least one electrochemically active material of the adsorption electrode, for example, carbon dioxide. In this way, it can advantageously be achieved that the volume evacuated from the gas separation chamber is usable product gas.

[0138] In a further embodiment, before the first adsorption and gas release operation and / or before the second adsorption and gas release operation, for example between the first adsorption and gas release operation and the second adsorption and gas release operation and / or between the second adsorption and gas release operation and the first adsorption and gas release operation, the first and / or second R. 409539 gas separation cell(s) is installed.

[0139] - 27 -

[0140] The gas separation chamber is partially or completely evacuated. Gas, particularly gaseous Lewis acid, evacuated from the first and / or second gas separation chamber of a cell can be returned to a gas separation chamber, for example, of the same cell or another, such as an adjacent, cell. This advantageously allows further gaseous Lewis acid to be desorbed, released, and / or removed, thereby achieving an improved yield of the gaseous Lewis acid.

[0141] In a further embodiment, adsorptive fine purification of the gaseous Lewis acid is carried out at the end of the first and / or second gas separation chamber. For this purpose, a fine purification device can be provided at the end of the first and / or gas separation chamber of the gas separation cell(s).

[0142] With regard to further technical features and advantages of the operating method according to the invention, explicit reference is hereby made to the explanations in connection with the gas separation cell and the gas separation system according to the invention, as well as to the figure and the description of the figures.

[0143] drawing

[0144] Further advantages and advantageous embodiments of the objects according to the invention are illustrated by the drawing and explained in the following description. It should be noted that the drawing is for descriptive purposes only and is not intended to limit the invention in any way. It shows

[0145] Fig. 1 shows a schematic cross-section through an embodiment of an electrochemical gas separation cell according to the invention for an electrochemical gas separation system according to the invention. R. 409539

[0146] - 28 -

[0147] Figure 1 shows that the electrochemical gas separation cell 10 for the electrochemical separation of a gaseous Lewis acid, for example carbon dioxide, from a fluid mixture containing the Lewis acid, in particular a gas mixture, in the embodiment shown therein, comprises a first adsorption electrode 20 with at least one electrochemically active material for the reversible electrochemical adsorption of the Lewis acid, for example para-anthraquinone (PAQ), and a second adsorption electrode 20' with at least one electrochemically active material for the reversible electrochemical adsorption of the Lewis acid, for example para-anthraquinone (PAQ). A separator 30 is arranged between the first adsorption electrode 20 and the second adsorption electrode 20'.

[0148] A first membrane 60 is arranged between the first adsorption electrode 20 and a first feed chamber 50 for supplying the fluid mixture, in particular to the first adsorption electrode 20. A second membrane 60' is arranged between the second adsorption electrode 20' and a second feed chamber 50' for supplying the fluid mixture, in particular to the second adsorption electrode 20'. Under the operating conditions of the cell 10, the first and second membranes 60 and 60' can each be permeable to the Lewis acid in a liquid and / or electrolyte-soluble state and impermeable to the Lewis acid in a gaseous state. For example, under the operating conditions of the cell 10, the first and second membranes 60 and 60' can be porous, liquid- and / or electrolyte-impregnated membranes.The first and second membrane 60,60' advantageously separate the first and second feed chamber 50,50' and thus the raw gas from the separated Lewis acid (CO2), which can be released in a first and second gas separation chamber 80,80'.

[0149] Figure 1 further shows that the first gas separation chamber 80 is formed on the side of the first adsorption electrode 20 facing away from the first membrane 60 (and towards the separator 30), and the second gas separation chamber 80' is formed on the side of the second adsorption electrode 20' facing away from the second membrane 60' (and towards the separator 30). R. 409539

[0150] - 29 -

[0151] Separator 30 is arranged between the first gas separation chamber 80 and the second gas separation chamber 80'.

[0152] In the embodiment shown in Figure 1, the first and second gas separation chambers 80, 80' are formed at least partially by means of the separator 30, in particular by means of corrugations and / or a wave-like shape and / or a wave-like cross-section of the separator 30, and at least partially by means of gas separation channels formed in the first and second adsorption electrodes 20, 20', in particular with a concave shape and / or with a concave cross-section, and at least partially by means of first spacers 40 arranged between the first adsorption electrode 20 and the separator 30, in particular in gas separation channels, and by means of second spacers 40' arranged between the second adsorption electrode 20' and the separator 30, in particular in gas separation channels.

[0153] Figure 1 illustrates that the first and second gas separation chambers 80, 80' can be filled with at least one liquid electrolyte and / or at least one ionic liquid. The first and second gas separation chambers 80, 80' can, in particular, be configured such that the at least one liquid electrolyte and / or the at least one ionic liquid can be circulated or is circulated in a circuit (not shown).

[0154] Figure 1 indicates that the cell 10 shown therein can be connected to other such cells (not shown) via bipolar plates 70, 70' to form a gas separation system 100, wherein a bipolar plate 70, 70' can be arranged between each pair of adjacent gas separation cells 10, in particular for electrically conductive connection and / or for ionic insulating separation and / or for spatial separation of adjacent gas separation cells 10. In particular, a bipolar plate 70, 70' can be arranged between the first membrane 60 of a gas separation cell 10 and the adsorption electrode 20' and / or the second membrane 60', in particular the second membrane 60', of an adjacent gas separation cell (not shown). R. 409539

[0155] - 30 -

[0156] Figure 1 shows that the first and second feed chambers 50, 50' are each at least partially formed by means of a bipolar plate 70, 70'. In particular, a feed chamber 50 of a cell 10 and a feed chamber 50' of an adjacent cell can be formed by means of a bipolar plate 70, 70'. In the embodiment shown in Figure 1, the bipolar plates 70, 70' have grooves and / or a wave-like shape and / or a wave-like cross-section for at least partially forming the feed chamber 50, 50'.

[0157] Figure 1 also indicates, by means of the bipolar plates 70,70', that the gas separation cell 10 can be arranged in a stacked manner.

[0158] In principle, the gas separation cells 10 and the gas separation system 100 can have a horizontal or horizontal structure, in particular in the form of a stack with horizontal or horizontal planes, where Figure 1 would show a side view - similar to a side view of a stack of books on a table.

[0159] Preferably, however, the gas separation cells 10 and the gas separation system 100 have a vertical or perpendicular structure, in particular in the form of a stack with vertical or perpendicular planes, which is why Figure 1 preferably shows a top view – similar to a top view of vertically stacked books in a bookshelf. Due to the vertical structure, CO2 can flow upwards along the spacers 40, 40' and, for example, be collected and extracted in a suitable area of ​​the system 100.

[0160] The gas separation cell 10 shown in Figure 1 and the gas separation system 100 based thereon can advantageously be operated quasi-continuously by means of electrochemical (potential) alternating adsorption, for example in two, in particular alternating, phases, namely in a first adsorption and gas release operation and in a second first adsorption and gas release operation. R. 409539

[0161] - 31 -

[0162] In the first adsorption and gas release operation of the gas separation cell 10, the fluid mixture, in particular the gas mixture, containing the Lewis acid (CO2) can be passed through the first feed chamber 50 over the first membrane 60. The Lewis acid can dissolve, or become dissolved, in the first membrane 60, particularly in the liquid and / or electrolyte of the first membrane 60. In the liquid and / or electrolyte dissolved state, the Lewis acid can then diffuse through the first membrane 60 to the first adsorption electrode 20.In the first adsorption and gas release operation, a potential is set between the first adsorption electrode 20 and the second adsorption electrode 20' of the cell 10 such that the at least one electrochemically active material of the first adsorption electrode 20 is reduced by taking up electrons and by binding and / or adsorption of the Lewis acid, and the at least one electrochemically active material of the second.

[0163] The adsorption electrode 20' is oxidized by releasing electrons and gaseous Lewis acid, particularly into the second gas separation chamber 80'. The gas bubbles labeled CO2 in the second gas separation chamber 80' and the absence of these gas bubbles in the first gas separation chamber 80 in Figure 1 indicate that the cell in Figure 1 is in the first adsorption and gas release phase. During the first adsorption and gas release phase, the fluid mixture can flow, in particular, through the first feed chamber 50 and the Lewis acid can be adsorbed at the first adsorption electrode 20.

[0164] In a second adsorption and gas release operation of the gas separation cell 10 (not shown), the fluid mixture, in particular a gas mixture, containing the Lewis acid can then be passed through the second feed chamber 50' over the second adsorption electrode 20' and / or over the second membrane 60'. The Lewis acid can dissolve, or be dissolved, particularly in the second adsorption electrode 20' and / or in the second membrane 60', for example in the liquid and / or in the electrolyte. In the liquid and / or electrolyte-soluble state, the Lewis acid can be released through the second adsorption electrode 20' and / or through the second membrane 60'.

[0165] - 32 - through the second membrane 60' to the second adsorption electrode 20', diffuse. In the second adsorption and gas release operation, the potential set between the first and second adsorption electrode 20,20' is then reversed or polarized, particularly in comparison to the first adsorption and gas release operation, such that the at least one electrochemically active material of the second adsorption electrode 20' is reduced by accepting electrons and by binding and / or adsorption of the Lewis acid, and the at least one electrochemically active material of the first adsorption electrode 20 is oxidized by releasing electrons and by releasing the gaseous Lewis acid, particularly into the first gas separation chamber 80.

[0166] In both the first and second adsorption and gas release operation, the Lewis acid carbon dioxide (CO2) can be adsorbed from the fluid mixture, in particular the gas mixture, thereby reducing its carbon dioxide content, so that the fluid mixture, in particular the gas mixture, after passing through / over the first or second feed chamber 50,50', may have a reduced carbon dioxide content or may even be essentially carbon dioxide-free.

Claims

R. 409539 - 33 - Claims 1. Electrochemical gas separation cell (10) for separating a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture, in particular a gas mixture, containing the Lewis acid. - a first adsorption electrode (20) with at least one electrochemically active material for reversible electrochemical adsorption of the Lewis acid, - a second adsorption electrode (20') with at least one electrochemically active material for reversible electrochemical adsorption of the Lewis acid and - a separator (30) arranged between the first adsorption electrode (20) and the second adsorption electrode (20'), wherein a first membrane (60) is arranged between the first adsorption electrode (20) and a first feed chamber (50) for supplying the fluid mixture 2. Gas separation cell (10) according to claim 1, wherein a second membrane (60') is arranged between the second adsorption electrode (20') and a second supply chamber (50') for supplying the fluid mixture.

3. Gas separation cell (10) according to claim 1 or 2, wherein the first membrane (60) and / or the second membrane (60'), in particular the first membrane (60) and the second membrane (60'), is permeable to the Lewis acid in a liquid and / or electrolyte-soluble state under the operating conditions of the cell (10), and wherein the first membrane (60) and / or the second membrane (60'), in particular the first membrane (60) and the second membrane (60'), is impermeable to the Lewis acid in the gaseous state under the operating conditions of the cell (10), in particular R. 409539 - 34 - wherein the first membrane (60) and / or the second membrane (60'), in particular the first membrane (60) and the second membrane (60'), is porous as such, and / or wherein the first membrane (60) and / or the second membrane (60'), in particular the first membrane (60) and the second membrane (60'), is liquid- and / or electrolyte-impregnated under the operating conditions of the cell (10), and / or wherein the first membrane (60) and / or the second membrane (60'), in particular the first membrane (60) and the second membrane (60'), is a porous, liquid- and / or electrolyte-impregnated membrane under the operating conditions of the cell (10).

4. Gas separation cell (10) according to one of claims 1 to 3, wherein a first gas separation chamber (80) is formed on the side of the first adsorption electrode (20) facing away from the first membrane (60') and / or facing the separator (30), and / or wherein a second gas separation chamber (80') is formed on the side of the second adsorption electrode (20') facing away from the second membrane (60') and / or facing the separator (30), and / or wherein the separator (30) is arranged between the first gas separation chamber (80) and the second gas separation chamber (80').

5. Gas separation cell (10) according to claim 4, wherein the first gas separation chamber (80) and / or the second gas separation chamber (80') is at least partially formed by means of the separator (30), in particular wherein the separator (30) has grooves and / or a wave-like shape and / or a wave-like cross-section for at least partially forming the first gas separation chamber (80) and / or the second gas separation chamber (80'), and / or wherein gas separation channels are formed in the separator (30) which extend in a direction parallel to the plane of the separator (30), and / or wherein gas passage openings are formed in the separator (30) which extend in a direction perpendicular to the plane of the separator (30). R. 409539 - 35 - extend through the separator (30), in particular wherein the gas passage openings connect the first gas separation chamber (80) and the second gas separation chamber (80').

6. Gas separation cell (10) according to claim 4 or 5, wherein the first gas separation chamber (80) is formed at least partially by means of the first adsorption electrode (20) and / or the second gas separation chamber (80') is formed at least partially by means of the second adsorption electrode (20'), in particular wherein gas separation channels are formed in the first adsorption electrode (20) and / or in the second adsorption electrode (20'), in particular which extend in a direction parallel to the plane of the adsorption electrode (20, 20'), in particular wherein the gas separation channels of the first adsorption electrode (20) and / or the second adsorption electrode (20') are formed with a concave shape and / or with a concave cross-section and / or are groove-like.

7. Gas separation cell (10) according to one of claims 4 to 6, wherein the first gas separation chamber (80) is formed at least partially by first spacers (40) arranged between the first adsorption electrode (20) and the separator (30), in particular for separating the separator (30) from the first adsorption electrode (20), and / or wherein the second gas separation chamber (80') is formed at least partially by second spacers (40') arranged between the second adsorption electrode (20') and the separator (30), in particular for separating the separator (30) from the second adsorption electrode (20'), and / or wherein the first spacers (40) are arranged and / or formed in the gas separation channels of the first adsorption electrode (20) and / or the second spacers (40') are arranged and / or formed in the gas separation channels of the second adsorption electrode (20').

8. Gas separation cell (10) according to one of claims 1 to 7, R. 409539 - 36 - wherein the gas separation cell (10) has a vertical structure, in particular wherein the first adsorption electrodes (20) and / or the second adsorption electrodes (20') and / or the separator (30) and / or the first feed chamber (50) and / or the second feed chamber (50') and / or the first membrane (60) and / or the second membrane (60') and / or the first gas separation chamber (80) and / or the second gas separation chamber (80') and / or the gas separation channels have a substantially vertical extension, or wherein the gas separation cell (10) has a horizontal structure,in particular wherein the first adsorption electrodes (20) and / or the second adsorption electrodes (20') and / or the separator (30) and / or the first feed chamber (50) and / or the second feed chamber (50') and / or the first membrane (60) and / or the second membrane (60') and / or the first gas separation chamber (80) and / or the second gas separation chamber (80') and / or the gas separation channels have a substantially horizontal extent.

9. Gas separation cell (10) according to one of claims 4 to 8, wherein the first gas separation chamber (80) and / or the second gas separation chamber (80') can be filled and / or is filled with at least one liquid electrolyte and / or with at least one ionic liquid, in particular wherein the first gas separation chamber (80) and / or the second gas separation chamber (80') is configured such that the at least one liquid electrolyte and / or the at least one ionic liquid can be circulated or is circulated.

10. Gas separation cell (10) according to any one of claims 1 to 9, wherein the Lewis acid is carbon dioxide, carbonyl sulfide, sulfur dioxide, sulfur trioxide, a sulfuric acid ester, nitrogen dioxide, nitrogen trioxide, a phosphoric acid ester, a sulfide, a carboxylic acid ester, an aldehyde, a ketone, an isocyanate, an isothiocyanate, a borane or a borate or a combination thereof, in particular wherein the Lewis acid is carbon dioxide (CO2). R. 409539 - 37 - 11. Gas separation system (100) for separating a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture, in particular a gas mixture, containing the Lewis acid, comprising at least two electrochemical gas separation cells (10) according to any one of claims 1 to 10.

12. Gas separation system (100) according to claim 11, wherein a bipolar plate (70, 70') is arranged between two adjacent gas separation cells (10), and / or wherein a bipolar plate (70) is arranged between the first membrane (60) of a gas separation cell (10) and the second adsorption electrode (20') and / or the second membrane (60'), in particular the second membrane (60'), of a gas separation cell adjacent thereto, and / or wherein the first feed chamber (50) and / or the second feed chamber (50') is formed at least partially by means of the bipolar plate (70, 70'), and / or wherein a feed chamber (50) of a cell (10) and a feed chamber (50') of a cell adjacent thereto is formed by means of a bipolar plate (70, 70'), and / or wherein the bipolar plate (70, 70') is used to form at least part of the feed chamber (50,50') grooves and / or a wave-like shape and / or a wave-like cross-section, and / or wherein in the bipolar plate (70,70') supply channels are formed which extend in a direction parallel to the plane of the bipolar plate (70,70').

13. Gas separation system (100) according to claim 11 or 12, wherein the first feed chamber (50) is formed at least partially by means of a gas-conducting, in particular gas-conducting and electrically conductive, intermediate layer between the first membrane (60) and an adjacent bipolar plate (70') and / or wherein the second feed chamber (50') is formed at least partially by means of a gas-conducting, in particular gas-conducting and electrically conductive, intermediate layer between the second adsorption electrode (20') and / or R. 409539 - 38 - the second membrane (60'), in particular the second membrane (60'), and a bipolar plate (70') adjacent to it.

14. Gas separation system (100) according to one of claims 11 to 13, wherein the gas separation cells (10) are arranged in a stack, wherein the gas separation cells (10) are arranged in the form of a vertical stack or in the form of a horizontal stack, in particular in the form of a vertical stack, and / or wherein the first membrane (60) and / or the second membrane (60') is at least partially electrically conductive;and / or wherein the bipolar plate (70, 70') has contact points which penetrate the first membrane (60) and / or the second membrane (60'), and / or wherein the first membrane (60) has through-holes through which the bipolar plate (70') extends partially to the first adsorption electrode (20), and / or wherein the second membrane (60') has through-holes through which the bipolar plate (70) extends partially to the second adsorption electrode (20'), in particular wherein the bipolar plate (70, 70') closes and / or seals the holes, and / or wherein the first adsorption electrode (20) and / or the second adsorption electrode (20') have metallic structures for electrical contacting the bipolar plate (70, 70').

15. Operating method for operating a gas separation cell (10) according to one of claims 1 to 10 and / or a gas separation system (100) according to one of claims 11 to 14 for separating a gaseous Lewis acid, in particular carbon dioxide, from a fluid mixture, in particular a gas mixture, containing the Lewis acid, in which the gas separation cell (10) or the gas separation cells (10) are operated by means of electrochemical alternating adsorption, in particular potential-swiveling adsorption, in particular quasi-continuously, in particular R. 409539 - 39 - wherein in a first adsorption and gas release operation of the gas separation cell (10) the fluid mixture containing the Lewis acid, in particular a gas mixture, is passed through the first feed chamber (50) over the first membrane (60) and a potential is set between the first adsorption electrode (20) and the second adsorption electrode (20') of the cell (10) such that the at least one electrochemically active material of the first adsorption electrode (20) is reduced by accepting electrons and by binding and / or adsorption of the Lewis acid and the at least one electrochemically active material of the second adsorption electrode (20') is oxidized by releasing electrons and by releasing the gaseous Lewis acid, in particular into the second gas separation chamber (80'), and / or wherein in a second adsorption and gas release operation of the gas separation cell (10) the fluid mixture containing the Lewis acid, in particular a gas mixture,through the second feed chamber (50') via the second adsorption electrode (20') and / or via the second membrane (60'), in particular via the second membrane (60'), and the potential set between the first adsorption electrode (20) and the second adsorption electrode (20') of the cell (10), in particular compared to the first adsorption and gas release operation, is reversed or polarized such that the at least one electrochemically active material of the second adsorption electrode (20') is reduced by taking up electrons and by binding and / or adsorption of the Lewis acid, and the at least one electrochemically active material of the first adsorption electrode (20) is oxidized by giving up electrons and by releasing the gaseous Lewis acid, in particular into the first gas separation chamber (80).

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