Process and apparatus for capturing co 2 from a co 2-containing gas mixture

Abstract

Disclosed herein is a process of capturing CO2 from a CO2-containing gas mixture, the method comprising the steps of: a) Contacting the CO2-containing gas mixture in a contactor (2) with a liquid capture solvent, thereby obtaining a CO2-depleted gas stream and a CO2-loaded capture solvent comprising bicarbonate ions and / or carbonate ions; b) Supplying the CO2-loaded capture solvent to an electrodialysis unit (4); c) Subjecting the CO2-loaded capture solvent to an electrodialysis treatment in the electrodialysis unit (4), comprising contacting the CO2-loaded capture solvent with an ion exchange membrane, thereby obtaining a regenerated liquid capture solvent; and d) Supplying the regenerated liquid capture solvent from the electrodialysis unit (4) to the contactor (2) for being contacted with the CO2-containing gas mixture according to step a).

Description

[0001] P29247PC00 March 2026

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[0003] Process and Apparatus for Capturing CO2 from a CO2-containing Gas Mixture

[0004] FIELD OF THE INVENTION

[0005] The present disclosure relates to a process of capturing CO2from a C02-containing gas mixture, and an apparatus for capturing CO2from a C02-containing gas mixture.

[0006] BACKGROUND OF THE INVENTION

[0007] To meet the world's climate goals, it is not enough to reduce emissions, but carbon dioxide must be actively removed from the atmosphere. As an example, to meet the 1.5-degree target, climate scenarios show that ~2-3 Gt of carbon dioxide per year will need to be captured by 2030 and up to 10 Gt by 2050.

[0008] Carbon dioxide removal (CDR) approaches have been developed to achieve net negative carbon dioxide emissions. Some of these approaches rely on capture from air, which is particularly challenging because of the low concentration of carbon dioxide in the air (about 0.04%, 419 ppm).

[0009] A particularly promising technological approach relies on a combination of air contactors to capture carbon dioxide in a sorbent, and electrochemical-based desorption processes. For example, electrochemical processes may be used to acidify a loaded solvent to release carbon dioxide. After release of carbon dioxide, the sorbent is typically recycled back to the air contactor. These approaches hold the promise of high scalability, modularity and high energy efficiency. Furthermore, electrochemical systems would allow fully electric operations, aligning better with decarbonized energy grids and reducing the need for heat production.

[0010] However, the known capture processes suffer from a range of disadvantages. For example, overall process efficiency is still low and there is room for improvement. Eventually, it would be desirable to minimize the energy consumption required for carbon dioxide capture. However, this requires optimized process control and balancing competing process requirements to achieve high overall process efficiency. A further challenge isP29247PC00 March 2026

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[0012] to find a compatible and mutually beneficial combination of absorption technology, sorbent material and desorption technology. For example, optimizing desorption alone often leads to process requirements which impede efficient absorption and therefore decrease overall process efficiency. Solving this multi-dimensional challenge is difficult. Consequently, there is a need to advance the state of the art in the field of carbon capture. There is a particular need to improve the known capture technologies relying on air capture and electrochemical carbon dioxide release.

[0013] SUMMARY OF THE DISCLOSURE

[0014] It is the general object of the present disclosure to advance the state of the art in the field of capturing CO2 from a CCh-containing gas mixture, and preferably to overcome at least some of the disadvantages of the prior art, such as the ones discussed above, fully or at least partly. In advantageous embodiments, the present disclosure provides a carbon capture process with high overall process efficiency. Ideally, energy consumption per ton of captured carbon dioxide would be minimized. In particular, at least in some embodiments, the process would balance the competing needs of the absorption step and of the desorption step such that a maximum overall process efficiency would be achieved. Further objects of at least some embodiments include to provide a process which is easy to perform, easy to control and / or scalable. A further object in at least some embodiments is to minimize the cost, especially operating expenditure, associated with the carbon capture process.

[0015] The general object is achieved by the subject-matter of the independent claims. Further favorable embodiments follow from the dependent claims and the overall disclosure. In a first aspect, the present invention provides a process of capturing CO2 from a CO2-containing gas mixture, the method comprising the steps of:

[0016] a) Contacting the C02-containing gas mixture in a contactor with a liquid capture solvent, thereby obtaining a CO2-depleted gas stream and a C02-loaded capture solvent comprising bicarbonate ions and / or carbonate ions;

[0017] b) Supplying the C02-loaded capture solvent to an electrodialysis unit;P29247PC00 March 2026

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[0019] c) Subjecting the C02-loaded capture solvent to an electrodialysis treatment in the electrodialysis unit, comprising contacting the C02-loaded capture solvent with an ion exchange membrane, thereby obtaining a regenerated liquid capture solvent; and d) Supplying the regenerated liquid capture solvent from the electrodialysis unit to the contactor for being contacted with the C02-containing gas mixture according to step a).

[0020] This general process was found to be highly scalable and efficient for removal of carbon dioxide, especially from gases with low carbon dioxide concentrations such as air. In particular, the use of electrodialysis over alternative options for removal of bicarbonate and / or carbonate ions enables high energy efficiency. The inventors have made various further improvements to this general process which will be described herein.

[0021] It is understood that the steps of the process described herein (in particular including steps a)-d)) are typically sequentially repeated multiple times. In other words, the steps of the method described herein may be described to form a repetition cycle which is repeated multiple times, e.g. at least 10 times, preferably at least 100 times. In still other words, in a typical embodiment, the method comprises continuously repeating a sequence of steps described herein (including in particular steps a)-d)).

[0022] To facilitate understanding of the disclosure, the following description includes certain headings for specific sections. However, despite the inclusion of headings, all sections are nevertheless part of a unified disclosure.

[0023] Load Level Checkpoint

[0024] The inventors have realized that while the process requirements for optimization of some of the different steps of the process may be aligned, certain steps may have specific needs or requirements which may be non-aligned with or even contradictory to the needs or requirements of other steps. As an example, in embodiments in which the liquid capture solvent comprises bicarbonate (e.g. in the form of potassium bicarbonate), carbon dioxide capture is usually most efficient at low initial bicarbonate concentrations, but for the electrodialysis, it would be advantageous to have a high bicarbonate concentration. Balancing these non-aligned needs requires process optimization. A possible solution could be to increase the contact time during the contacting step a). However, becauseP29247PC00 March 2026

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[0026] the rate of carbon dioxide capture typically also depends on the bicarbonate concentration, there will again be an optimal window to be achieved. Thus, more broadly, the contacting step and the electrodialysis treatment step may impose different requirements on the load level.

[0027] In some embodiments, the process further comprises between steps a) and b), the step of determining a load level of the C02-loaded capture solvent at a load level checkpoint, - Wherein if the determined load level exceeds a target minimum load level, the C02-loaded capture solvent is supplied to the electrodialysis unit according to step b) for the subsequent electrodialysis treatment according to step c);

[0028] - Wherein if the determined load level does not exceed the target minimum load level, at least a bypass portion of the C02-loaded capture solvent is recycled to the contactor, bypassing the electrodialysis unit.

[0029] These embodiments are particularly advantageous as they allow reaching the target minimum load level with high efficiency. In particular, by bypassing the electrodialysis treatment, which is typically energy intensive, the overall energy efficiency of the process is improved. For example, the embodiments may be used to ensure that the typically energy intensive electrodialysis treatment is only performed if the solvent has a minimum load level, thereby avoiding inefficient cycles in which the solvent is loaded only minimally, which would make the electrodialysis treatment inefficient. More broadly, the embodiments allow the overall system to be operated with high efficiency by balancing the competing needs of the electrodialysis and of the contactor.

[0030] If the determined load level does not exceed the target minimum load level, at least the bypass portion is recycled to the contactor, bypassing the electrodialysis unit. It is understood that the bypass portion is recycled to the contactor for being contacted with the C02-containing gas mixture according to step a). It is further understood that the bypass portion bypasses the electrodialysis unit, i.e. is not supplied to the electrodialysis unit but instead is supplied to the contactor. Furthermore, in a typical embodiment, the CO2-loaded capture solvent is supplied to the electrodialysis unit from the load level checkpoint. Furthermore, in a typical embodiment, the bypass portion of the C02-loaded capture solvent is recycled to the contactor from the load level checkpoint.P29247PC00 March 2026

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[0032] Typically, the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint is carried out by a load level checkpoint unit. The load level checkpoint unit is arranged at the load level checkpoint.

[0033] The load level checkpoint may be arranged in different positions. In a typical embodiment, the load level checkpoint is arranged with respect to a direction of flow of the capture solvent between the contactor and the electrodialysis unit. In other words, the load level checkpoint may be said to be arranged downstream of the contactor and upstream of the electrodialysis unit.

[0034] Furthermore, in a typical embodiment, the load level checkpoint (respectively the load level checkpoint unit) is fluidically interconnected with an inlet (e.g. a second inlet) of the contactor by a bypass conduit bypassing the electrodialysis unit.

[0035] Depending on the application, the load level checkpoint (respectively the load level checkpoint unit) may optionally be arranged inside a housing in which the contactor may optionally also be arranged. For example, the load level checkpoint (respectively the load level checkpoint unit) may optionally be arranged at a first outlet of the contactor and inside the housing in which the contactor is also arranged.

[0036] The load level of the C02-loaded capture solvent generally relates to the amount of carbon dioxide with which the capture solvent is loaded. As the skilled person understands, although the capture solvent could be loaded literally with the molecule carbon dioxide (e.g. through solubilized amounts of carbon dioxide in the solvent), more preferably, the capture solvent is loaded with carbon dioxide in a different form, preferably in the form of bicarbonate and / or carbonate ions. Other forms of carbon dioxide are also conceivable.

[0037] The load level of the C02-loaded capture solvent may be determined in different ways. In some embodiments, the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint comprises one or more of the following:

[0038] - determining a total inorganic carbon (TIC) concentration of the C02-loaded capture solvent;

[0039] - determining a bicarbonate concentration of the C02-loaded capture solvent; - determining a carbonate concentration of the C02-loaded capture solvent;P29247PC00 March 2026

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[0041] - determining a pH of the C02-loaded capture solvent;

[0042] - determining a conductivity of the C02-loaded capture solvent;

[0043] - determining a volume of the C02-loaded capture solvent;

[0044] - determining a flow rate of the C02-loaded capture solvent.

[0045] As the skilled person knows, depending on the determination of the load level, the load level checkpoint unit may comprise appropriate instruments or tools to determine the load level. As an example, the load level checkpoint unit may comprise a pH meter and / or a conductivity meter.

[0046] The different variants listed above were found to be advantageous because they allow easy and reliable determination of the load level. TIC concentration measurement, pH measurement and conductivity measurement were found to be particularly advantageous. Thus, in preferred embodiments, the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint comprises one or more of the following:

[0047] - determining a total inorganic carbon concentration of the C02-loaded capture solvent;

[0048] - determining a pH of the C02-loaded capture solvent;

[0049] - determining a conductivity of the C02-loaded capture solvent.

[0050] As the skilled person knows, total inorganic carbon refers to the sum of all inorganic carbon species. The total inorganic carbon includes in particular the chemical species bicarbonate (HCO3“), carbonate (CO32-), carbonic acid (H2CO3) and (dissolved) carbon dioxide. As the skilled person also knows, at least some of the TIC species, when dissolved in water, are typically in a chemical equilibrium with each other. This equilibrium tends to be pH dependent. Depending on the application, it may be more advantageous to measure the TIC concentration as a whole, or to measure the bicarbonate concentration in particular, or even both.

[0051] Depending on the application, it can be useful to observe certain parameters in absolute terms, e.g. to monitor the absolute pH or conductivity of the capture solvent overtime.P29247PC00 March 2026

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[0053] However, it can also be useful to determine a change of a certain parameter overtime, e.g. in the sense of a first derivative of a graph of a measurement parameter over time. In some embodiments, the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint comprises one or more of the following:

[0054] - Determining a change of a total inorganic carbon concentration of the C02-loaded capture solvent overtime;

[0055] - Determining a change in a pH of the C02-loaded capture solvent overtime; - Determining a change in a conductivity of the C02-loaded capture solvent over time.

[0056] For example, determining a change in any of these parameters over time can make it easier to determine if the minimum load level has been reached or not. In particular, the influence of certain interfering effects on the measurement can be minimized by determining the first derivative.

[0057] The target minimum load level is a minimum load level of the C02-loaded capture solvent that is targeted, i.e. intended or envisioned. This target minimum load level must be exceeded for the C02-loaded capture solvent to be supplied to the electrodialysis unit for electrodialysis treatment. Depending on how the load level is determined, the target minimum load level may be expressed by way of different parameters and / or units. As an example, the target minimum load level may be a target minimum TIC concentration (and / or a target minimum bicarbonate concentration). Alternatively or in combination, the target minimum load level may be expressed by way of a target threshold pH. If the determined pH is lower than the target threshold pH, the target minimum load level is exceeded (because increased loading typically leads to a decrease in pH).

[0058] Regardless of whether absolute numbers or derivatives are determined, depending on the application, one or more of the parameters mentioned above can be determined. A particularly easy process control is achieved when determining the load level only on the basis of a determined conductivity as the sole parameter measured for determining the load level. It was found, surprisingly, that the conductivity as the sole parameter can still be used for determining the load level. This is surprising because many different factors influence conductivity, including e.g. ionic composition, ionic concentration, etc.P29247PC00 March 2026

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[0060] It would therefore be expected that multiple parameters would need to be determined to accurately determine the load level. However, surprisingly, it was found that only determining conductivity is sufficient to then determine the load level accurately.

[0061] Accordingly, in some embodiments, the step of determining the load level of the CO2-loaded capture solvent at the load level checkpoint comprises measuring the conductivity of the C02-loaded capture solvent and then determining the load-level based only on the measured conductivity as the sole measured parameter for determining the load level. In other words, the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint comprises measuring the conductivity of the C02-loaded capture solvent as the only parameter measured for determining the load level of the C02-loaded capture solvent.

[0062] In further embodiments, however, a pH of the capture solvent is measured. Thus, for example, the target minimum load level may be:

[0063] - Exceeded if the pH of the C02-loaded capture solvent is determined to be lower than a target threshold pH; and

[0064] - Not exceeded if the pH of the C02-loaded capture solvent is determined to be equal to or higher than the target threshold pH.

[0065] An advantage of using a target threshold pH is that pH measurements are highly accurate and easy to perform, making the process efficient, cheap and precise.

[0066] The inventors have found that a target threshold pH of less than 11.0, preferably less than 10.5, particularly less than 10.0, e.g. in a range from 8.5 to 9.9, preferably in a range from 9.1 to 9.9, more preferably in a range from 9.3 to 9.7, is particularly advantageous to achieve high overall process efficiency. In particular, the energy required for each ton of captured carbon dioxide was found to be minimal when using a target threshold pH in these ranges. The target threshold pH is a solution to a complex multi-dimensional optimization problem, which balances several aligned and non-aligned process requirements.

[0067] Thus, in some embodiments, the target threshold pH is selected to be less than 11.0, e.g. less than 10.0. Preferably, in some embodiments, the target threshold pH is selected to be less than 10.5, such as in a range from 8.5 to 9.9. In some embodiments, the targetP29247PC00 March 2026

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[0069] threshold pH is selected to be in a range from 9.1 to 9.9, more preferably in a range from 9.3 to 9.7. In some embodiments, the target threshold pH is 9.5.

[0070] Irrespective of the specific target minimum load level, as was described above, at least a bypass portion of the C02-loaded capture solvent may be recycled to the contactor, bypassing the electrodialysis unit, if the determined load level does not exceed the target minimum load level. In some embodiments, the bypass portion makes up at least 10 vol. -% of the C02-loaded capture solvent whose load level was determined at the load-level checkpoint. Optionally, the bypass portion may make up at least 50 vol.-% of the CO2-loaded capture solvent whose load level was determined at the load-level checkpoint. In some embodiments, the bypass portion makes up essentially all of the C02-loaded capture solvent whose load level was determined at the load-level checkpoint. In other words, in these embodiments, if the determined load level does not exceed the target minimum load level, the C02-loaded capture solvent is recycled to the contactor, bypassing the electrodialysis unit.

[0071] Irrespective of the size or fraction of the bypass portion, depending on the application, the bypass portion may be recycled to the contactor either directly or indirectly. Furthermore, the bypass portion may optionally be merged with other streams. For example, in some embodiments, the bypass portion is combined with the regenerated capture solvent at a recycling merge point, thereby forming a combined recycling stream which is supplied to the contactor. The merge point may e.g. be arranged in a direction of flow of the regenerated liquid capture solvent between the electrodialysis unit and the contactor. In other words, the merge point may e.g. be arranged downstream of the electrodialysis unit and upstream of the contactor.

[0072] In some embodiments, the merge point is arranged at the upgrading unit or the merge point is arranged upstream of the upgrading unit. One advantage of these embodiments is that they allow the recycling stream and the regenerated liquid capture solvent to be subjected to the upgrading jointly.

[0073] In some embodiments, the bypass portion is recycled to the contactor separately from the regenerated capture solvent. One advantage of these embodiments is that they facilitate process control and that the bypass portion can optionally be injected at different positions of the contactor than the regenerated capture solvent, thereby increasing flexibility and allowing higher overall process efficiency. More broadly, because the bypassP29247PC00 March 2026

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[0075] portion may have a different composition (e.g. different load level) than the regenerated capture solvent, separately recycling them allows to treat them according to their respective compositions (e.g. load levels).

[0076] In some embodiments, as described above, the load level determined at the load level checkpoint may be checked with respect to a target minimum load level. Alternatively or in combination, the determined load level may also be checked with respect to a target maximum load level. The target maximum load level may e.g. be used to provide feedback instructions to the contactor to make sure that the subsequent C02-loaded capture solvent will lie closer in a target range. As an illustrative example, if the load level is determined to be too high, the contactor could be instructed to take appropriate measures (e.g. reduce carbon dioxide-capture solvent contact time, etc.) to make sure that the subsequently obtained C02-loaded capture solvent will have a lower load level. In some embodiments, if the determined load level exceeds a target maximum load level, at least one control parameter for the contacting step a) is changed, such that the load level of the C02-loaded capture solvent obtained from the contactor in a subsequent repetition of step a) is reduced.

[0077] In some embodiments, if the determined load level exceeds a target maximum load level, at least one control parameter for the contacting step a) is changed as follows:

[0078] - A flow rate of the C02-containing gas mixture through the contactor in step a) is increased; and / or

[0079] - A flow rate of the liquid capture solvent through the contactor in step a) is increased; and / or

[0080] - An average time of contact between the C02-containing gas mixture and the liquid capture solvent in the contactor in step a) is decreased; and / or

[0081] - A pH of the liquid capture solvent with which the C02-containing gas mixture is contacted in the contactor in step a) is decreased.

[0082] It was found to be particularly advantageous to decrease an average time of contact between the C02-containing gas mixture and the liquid capture solvent in the contactor in step a).P29247PC00 March 2026

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[0084] The embodiments described in the previous paragraphs are advantageous because they increase overall process efficiency by allowing the C02-loaded capture solvent to maintain an efficient load level. Once again, non-aligned process needs can thereby be reconciled with each other in a way that the overall process efficiency is maximized.

[0085] In several further embodiments, it was found to be advantageous to use a contactor having at least a first contactor section and a second contactor section. The C02-con-taining gas mixture can be contacted with the liquid capture in the different contactor sections, and subsequently, the recycling can be optimized. Eventually, the different embodiments that will be described in the following contribute to increased overall process efficiency.

[0086] In some embodiments, the contactor comprises at least a first contactor section and a second contactor section, wherein in step a) the C02-containing gas mixture is contacted with the liquid capture solvent in the first contactor section and in the second contactor section. The step of determining the load level of the C02-loaded capture solvent at the load level checkpoint may comprise:

[0087] - determining a first load level of a first C02-loaded capture solvent fraction obtained from the first contactor section, and a second load level of a second CO2- loaded capture solvent fraction obtained from the second contactor section; and - determining, by comparing the first load level and the second load level, a lower loading efficiency contactor section corresponding to one of the first and second contactor section, and a higher loading efficiency contactor section corresponding to the other of the first and second contactor section.

[0088] Depending on the application, the first contactor section and the second contactor section may have different arrangements with respect to each other. In some embodiments, the first contactor section and the second contactor section are arranged with respect to a direction of flow of the liquid capture solvent next to each other (e.g. parallel to each other) or behind each other. For example, where the first contactor section and the second contactor section are arranged behind each other with respect to a direction of flow of the liquid capture solvent, the liquid capture solvent may e.g. first pass through the first contactor section and then through the second contactor section (or vice versa). Where the first contactor section and the second contactor section are arranged withP29247PC00 March 2026

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[0090] respect to a direction of flow of the liquid capture solvent next to each other, a first portion of the liquid capture solvent could pass through the first contactor section, and a second portion of the liquid capture solvent could pass through the second contactor section. In some embodiments, the first contactor section and the second contactor section are separate from each other, e.g. separated by a wall. In preferred embodiments, however, the first contactor section and the second contactor section may be fluidically interconnected with each other. For example, the first contactor section and the second contactor section may contact each other.

[0091] Knowledge about which contactor section has higher loading efficiency and which has lower loading efficiency can be used in multiple ways to increase process efficiency. For example, at least one control parameter for the lower loading efficiency contactor section may be changed, such that the load level of the C02-loaded capture solvent obtained from the lower loading efficiency contactor section in a subsequent repetition of step a) is increased.

[0092] In some embodiments, if the determined first load level and the determined second load level do not exceed the target minimum load level,

[0093] - The C02-loaded capture solvent fraction for which a lower load level was determined is recycled to the higher loading efficiency contactor section, bypassing the electrodialysis unit; and

[0094] - The other of the first and second C02-loaded capture solvent fraction for which a higher load level was determined is recycled to the lower loading efficiency contactor section, bypassing the electrodialysis unit.

[0095] These embodiments increase overall process efficiency by ensuring that after recycling of the first and second C02-loaded capture solvent fraction, the fractions will have more similar and more controlled load levels.

[0096] In some embodiments, if the determined first load level does not exceed the target minimum load level and the determined second load level exceeds the target minimum load level, at least a first bypass portion of the first C02-loaded capture solvent fraction is recycled to the higher loading efficiency contactor section, bypassing the electrodialysis unit. Preferably, the second C02-loaded capture solvent fraction may be supplied to theP29247PC00 March 2026

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[0098] electrodialysis unit according to step b) for the electrodialysis treatment according to step c).

[0099] Alternatively or in combination, if the determined second load level does not exceed the target minimum load level and the determined first load level exceeds the target minimum load level, at least a second bypass portion of the second C02-loaded capture solvent fraction is recycled to the higher loading efficiency contactor section, bypassing the electrodialysis unit. Preferably, the first C02-loaded capture solvent fraction may be supplied to the electrodialysis unit according to step b) for the electrodialysis treatment according to step c).

[0100] It is understood that the term “second bypass portion” of the second C02-loaded capture solvent is used to distinguish is more clearly from the “first bypass portion” of the first C02-loaded capture solvent. The term “second bypass portion of the second C02-loaded capture solvent” does not necessarily imply that there is also a “first bypass portion of the second C02-loaded capture solvent”.

[0101] Depending on the application and on the solvent, different target maximum load levels may be chosen. However, it was found to be particularly advantageous for the target maximum load level to be below a saturation load level of the C02-loaded capture solvent. The reason for this is that optimal energy efficiency of the overall process can be achieved if the C02-loaded capture solvent has a load level below the saturation load level.

[0102] In some embodiments, the target maximum load level is below a saturation load level of the capture solvent. For example, the target maximum load level may be at least 1%, e.g. at least 2%, e.g. at least 3%, e.g. at least 4%, e.g. at least 5%, e.g. at least 6%, e.g. at least 7%, e.g. at least 8%, e.g. at least 9%, e.g. at least 10%, below the saturation load level of the capture solvent.

[0103] In some embodiments, the step of contacting the C02-containing gas mixture in the contactor with the liquid capture solvent is performed such that the obtained C02-loaded capture solvent has a load level below a saturation load level of the capture solvent (for example, at least 1%, e.g. at least 2%, e.g. at least 3%, e.g. at least 4%, e.g. at least 5%, e.g. at least 6%, e.g. at least 7%, e.g. at least 8%, e.g. at least 9%, e.g. at least 10%, e.g. at least 15%, below the saturation load level of the capture solvent).P29247PC00 March 2026

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[0105] In other words, in some embodiments, the step of contacting the C02-containing gas mixture in the contactor with the liquid capture solvent is performed such that the obtained C02-loaded capture solvent has a load level below saturation of the C02-loaded capture solvent (for example, at least 1%, e.g. at least 2%, e.g. at least 3%, e.g. at least 4%, e.g. at least 5%, e.g. at least 6%, e.g. at least 7%, e.g. at least 8%, e.g. at least 9%, e.g. at least 10%, e.g. at least 15%, below saturation of the C02-loaded capture solvent). In some embodiments, the C02-loaded capture solvent that is supplied to the electrodialysis unit in step b) has a load level below a saturation load level of the capture solvent (for example, at least 1%, e.g. at least 2%, e.g. at least 3%, e.g. at least 4%, e.g. at least 5%, e.g. at least 6%, e.g. at least 7%, e.g. at least 8%, e.g. at least 9%, e.g. at least 10%, e.g. at least 15%, below the saturation load level of the capture solvent).

[0106] In other words, in some embodiments, the C02-loaded capture solvent that is supplied to the electrodialysis unit in step b) has a load level below saturation of the C02-loaded capture solvent (for example, at least 1%, e.g. at least 2%, e.g. at least 3%, e.g. at least 4%, e.g. at least 5%, e.g. at least 6%, e.g. at least 7%, e.g. at least 8%, e.g. at least 9%, e.g. at least 10%, e.g. at least 15%, below saturation of the C02-loaded capture solvent). It is understood that the saturation load level of the capture solvent refers to CO2, i.e. to a CO2loading of the capture solvent (typically in the form of bicarbonate and / or carbonate ions). The saturation load level of the capture solvent is a maximum load level of the capture solvent. In other words, the saturation load level of the capture solvent corresponds to the highest (CO2) load level that the capture solvent can have under the process conditions. In still other words, the saturation load level corresponds to the (CO2) load level at which the capture solvent is saturated with carbon dioxide, i.e. it cannot take up, retain and then transport to the electrodialysis unit any additional carbon dioxide. It is understood that “saturated with carbon dioxide” does not imply that the carbon dioxide is bound in the form of CO2. Rather, it may for example be bound in the capture solvent in the form of chemical equivalents of carbon dioxide, in particular in the form of bicarbonate and / or carbonate ions.

[0107] The load level (e.g. the saturation load level) as used herein refers to a level of carbon dioxide loading by the capture solvent. The load level may for example be determined in absolute terms, e.g. as an amount (e.g. in mol) of loaded carbon dioxide (respectivelyP29247PC00 March 2026

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[0109] carbon dioxide equivalents) divided by an amount of the capture solvent (e.g. in mol or in ml_). Thus, the load level may for example be a concentration of loaded carbon dioxide in the capture solvent.

[0110] Capture Solvent

[0111] The process described herein makes use of a liquid capture solvent. It is understood that the capture solvent is typically liquid at standard conditions, e.g. at 25 °C and 1 bar. It is also understood that the capture solvent undergoes different chemical processes and, as such, changes its compositions and properties over the course of the process. To reflect this in the terminology used, the present disclosure distinguishes at least between the liquid capture solvent, the C02-loaded capture solvent and the regenerated liquid capture solvent.

[0112] The liquid capture solvent generally refers to the capture solvent with which the CO2-containing gas mixture is contacted in the contactor. Whenever the liquid capture solvent is described in further detail herein (e.g. regarding its components, their concentrations, etc.), the details generally refer to the liquid capture solvent before it has been contacted with the C02-containing gas mixture, unless clearly indicated otherwise or unless the context dictates otherwise.

[0113] The C02-loaded capture solvent is formed from the liquid capture solvent in the contactor upon loading of carbon dioxide. As explained herein, carbon dioxide is typically not loaded in the form of the molecule carbon dioxide, but rather in related forms. Typically, the C02-loaded capture solvent comprises bicarbonate ions and / or carbonate ions. As the skilled person knows, bicarbonate ions and carbonate ions are convertible into carbon dioxide, e.g. through acidification.

[0114] The regenerated liquid capture solvent is formed in the electrodialysis unit. It is subsequently supplied to the contactor for being contacted with the C02-containing gas mixture. Thus, the regenerated liquid capture solvent may in some embodiments be essentially identical to the liquid capture solvent. However, there may also be slight deviations or differences, e.g. slightly different concentrations, the presence of other byproducts e.g. form the electrodialysis, etc.P29247PC00 March 2026

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[0116] In some embodiments, the regenerated liquid capture solvent is upgraded in an upgrading unit before being supplied to the contactor for being contacted with the C02-contain-ing gas mixture. The upgrading unit is typically arranged in a direction of flow between the first outlet of the electrodialysis unit and the first inlet of the contactor.

[0117] In preferred embodiments, the upgrading comprises adjusting a pH of the regenerated liquid capture solvent. For example, the pH of the regenerated liquid capture solvent may be adjusted to the pH of the liquid capture solvent. For example, the pH of the regenerated liquid capture solvent may be adjusted to a pH of 10.0 or higher, preferably from 10.0 to 12.0, more preferably from 10.0 to 11.0.

[0118] In some embodiments, the upgrading comprises removing one or more impurities from the regenerated liquid capture solvent.

[0119] As used herein, the terms “upstream” and “downstream” generally refer to a direction of flow of the capture solvent, unless specifically indicated otherwise or unless the context clearly dictates otherwise.

[0120] Depending on the application, the liquid capture solvent may have a different pH. In some embodiments, the liquid capture solvent has a pH of 10.0 or higher, preferably from 10.0 to 12.0, more preferably from 10.0 to 11.0. It is understood that this pH refers to the liquid capture solvent before being contacted with the C02-containing gas mixture in step a). These pH ranges were found to be particularly advantageous to achieve high overall process efficiency and to minimize the energy required for each ton of captured carbon dioxide. More specifically, the inventors have found that for the process described herein which employs electrodialysis treatment, the indicated pH ranges strike an optimal balance between the different non-aligned needs and requirements of the different process steps.

[0121] In some embodiments, the liquid capture solvent comprises an amine. Preferably, the liquid capture solvent comprises the amine in an amount of at least 1 wt.-%, more preferably from 2 wt.-% to 20 wt.-%, even more preferably from 3 wt.-% to 10 wt.-%. One advantage of using an amine in the liquid capture solvent is to accelerate capture of carbon dioxide.

[0122] Depending on the application, different amines can be chosen, including mixtures of different amines.P29247PC00 March 2026

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[0124] In some embodiments, the amine is a tertiary amine such as N-methyldiethanolamine. In some embodiments, the amine is a secondary amine such as 2-(ethylamine) ethanol. In some embodiments, the amine is a primary amine such as monoethanolamine and / or 2-amino-2-methyl-1-propanol.

[0125] It was found to be particularly advantageous to use polymeric amines, such as polyethylene imine. Thus, in some embodiments, the amine is a polymeric amine, preferably polyethylene imine (PEI). One advantage of these polymeric amines, particularly PEI, is that they greatly accelerate bicarbonate formation. Without wishing to be bound to a theory, it is believed the PEI does not form significant amounts of carbamate but instead primarily leads to bicarbonate formation, which is advantageous for the process described herein as well, particularly for those variants in which the bicarbonate and or carbonate ions are removed through an anion-exchange membrane.

[0126] Depending on the application, different PEI sources may be used. Particularly good results were realized when the polyethylene imine has a molecular weight in a range from 500 Da to 5’000 Da, preferably from 800 Da to 3’000 Da, more preferably a molecular weight of 800 Da or 3’000 Da. In some embodiments, the PEI has a molecular weight in a range from 500 Da to 2500 Da, preferably from 500 Da to 1500 Da, more preferably from 500 Da to 1100 Da, such as 800 Da. However, in some embodiments, the PEI has a molecular weight in a range from 1500 Da to 4000 Da, preferably from 2000 Da to 4000 Da, more preferably from 2500 Da to 3500 Da, such as 3000 Da.

[0127] Whenever reference is made in the present disclosure (hereinbefore and hereinafter) to a molecular weight or a molecular weight range of PEI, the indicated molecular weight or molecular weight range preferably refers to weight average molecular weight (Mw). Furthermore, whenever reference is made in the present disclosure (hereinbefore and hereinafter) to PEI, the respective PEI can preferably be branched PEI, e.g. randomly branched PEI.

[0128] The inventors have also found that it is advantageous for the liquid capture solvent (before being contacted with the C02-containing gas mixture) to comprise bicarbonate and / or carbonate ions, preferably in the form of metal bicarbonate and / or metal carbonate. For example, enhanced carbon dioxide capture was observed and the metalP29247PC00 March 2026

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[0130] bicarbonate and / or metal carbonate was also useful to realize an advantageous target pH.

[0131] In some embodiments, the liquid capture solvent comprises a metal carbonate and / or a metal bicarbonate. For example, in some embodiments, the liquid capture solvent comprises the metal carbonate and / or the metal bicarbonate in a combined concentration of at least 0.1 M, more preferably in a combined concentration from 0.3 M to 3.0 M, even more preferably in a combined concentration from 0.4 M to 2.0 M, such as in a combined concentration from 0.5 M to 0.7 M. It is understood that the combined concentration of the previous sentence refers to the concentration of both the metal bicarbonate and the metal carbonate.

[0132] In preferred embodiments, the liquid capture solvent comprises at least a metal bicarbonate, preferably in a metal bicarbonate concentration from 0.3 M to 3.0 M, more preferably in a metal bicarbonate concentration from 0.4 M to 2.0 M, even more preferably in a metal bicarbonate concentration from 0.5 M to 0.7 M. Optionally, the liquid capture solvent may additionally comprise a metal carbonate.

[0133] In the embodiments described in the previous two paragraphs, the metal of the metal bicarbonate is preferably potassium. Irrespective of the choice of metal for the metal bicarbonate, in the embodiments described in the previous two paragraphs, the metal of the metal carbonate is preferably potassium. The use of potassium was found to be particularly advantageous for facilitating carbon dioxide capture, as well as unloading. Without wishing to be bound to a theory, it is believed that the potassium ion destabilizes carbamate intermediates in favor of bicarbonate ion formation.

[0134] In some embodiments, the liquid capture solvent comprises at least potassium bicarbonate, preferably in a potassium bicarbonate concentration of at least 0.1 M, e.g. in a potassium bicarbonate concentration from 0.3 M to 3.0 M, more preferably in a potassium bicarbonate concentration from 0.4 M to 1.0 M, even more preferably in a potassium bicarbonate concentration from 0.5 M to 0.7 M. Once again, as outlined above, it is understood that this concentration range refers to the liquid capture solvent, i.e. before being contacted with the C02-containing gas mixture in step a).P29247PC00 March 2026

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[0136] Contactor

[0137] The contactor is configured for contacting the C02-containing gas mixture with the liquid capture solvent. In some embodiments, the contactor comprises a packed column, which may e.g. comprise a structured packing material. The use of structured packing material allows to increase the surface area and thereby increase contact efficiency.

[0138] The contactor typically also comprises an irrigation system for distributing the liquid capture solvent across the packed column.

[0139] In some embodiment, the contactor further comprises a drift eliminator.

[0140] In some embodiments, the contactor is configured to contact the C02-containing gas mixture and the liquid capture solvent in a cross-flow orientation. For example, a first stream formed by the C02-containing gas mixture and a second stream formed by the liquid capture solvent may be contacted with each other at an angle of at least 20°, preferably at least 45 °C, for example from 50° to 130°, particularly from 80° to 100°. These embodiments allow optimal contact and minimal energy consumption.

[0141] Depending on the application, the contactor may have different inlets. For example, the contactor may have a first inlet for entry of the regenerated liquid capture solvent into the contactor. The contactor may also have a second inlet for entry of the bypass portion into the contactor. The first inlet and the second inlet may be different inlets, or they may be the same inlet.

[0142] The contactor typically has a first outlet for outlet of the C02-loaded capture solvent. The contactor typically also has a second outlet for outlet of the CO2-depleted gas stream. The first outlet and the second outlet of the contactor are typically different from each other. Namely, the first outlet is typically a liquid outlet, and the second outlet is typically a gas outlet.

[0143] Electrodialysis Unit

[0144] The C02-loaded capture solvent is subjected to the electrodialysis treatment in the electrodialysis unit. As the skilled person knows, the electrodialysis unit typically comprises a cathode, an anode and an electrodialysis stack arranged in stack direction between the cathode and the anode.P29247PC00 March 2026

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[0146] The electrodialysis treatment comprises contacting the C02-loaded capture solvent with an ion exchange membrane, thereby obtaining the regenerated liquid capture solvent. It is understood that the regenerated liquid capture solvent has a lower bicarbonate concentration and / or a lower carbonate concentration than the C02-loaded capture solvent. In typical embodiments, the electrodialysis treatment leads to formation of the regenerated liquid capture solvent and a separate solution comprising bicarbonate and / or carbonate ions.

[0147] In typical embodiments, the C02-loaded capture solvent is subjected to the electrodialysis treatment, thereby removing at least some of the bicarbonate ions and / or carbonate ions from the C02-loaded capture solvent, thereby obtaining the regenerated liquid capture solvent. As an example, during the electrodialysis treatment, at least some of the bicarbonate ions and / or at least some of the carbonate ions may be transferred through an anion-exchange membrane into a release solution, thereby obtaining the regenerated liquid capture solvent. Alternatively or in combination, during the electrodialysis treatment, at least some of the bicarbonate ions and / or carbonate ions may be removed from the C02-loaded capture solvent by transferring components of the C02-loaded capture solvent other than bicarbonate and / or carbonate ions through the ion-exchange membrane, e.g. components of a capture species. Thereby, the C02-loaded capture solvent could effectively be (re-)generated on an opposite side of the respective membrane, which also amounts to a net removal of at least some of the bicarbonate ions and / or carbonate ions from the C02-loaded capture solvent.

[0148] In some embodiments, the electrodialysis stack of the electrodialysis unit comprises at least one anion-exchange membrane (AEM). When the C02-loaded capture solvent contacts this AEM in step c), at least some of the bicarbonate ions and / or the carbonate ions may be transferred across the AEM and thereby removed from the C02-loaded capture solvent. Thus, the AEM may be configured to transfer at least some of the bicarbonate ions and / or carbonate ions from the C02-loaded capture solvent through the AEM into a release solution. It is understood that the C02-loaded capture solvent and the release solution are arranged on opposite sides of the AEM.

[0149] One advantage of using an electrodialysis stack comprising at least one AEM is that this allows the bicarbonate ions and / or carbonate ions to be transferred between two separate solvent streams, thereby avoiding modifying the pH of a single bulk solvent, whichP29247PC00 March 2026

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[0151] would be energy intensive due to the need to first acidify the bulk of the solvent, following by basification.

[0152] In preferred embodiments, the electrodialysis unit is a bipolar membrane (BPM) electrodialysis unit. These embodiments were found to display particularly high energy efficiency in the process described herein, especially when used in combination with the load level checkpoint (respectively the load level checkpoint unit) described herein. The bipolar membrane electrodialysis unit may optionally be abbreviated as BPMED unit. As the skilled person knows, a BPMED unit typically comprises a cathode, an anode and a bipolar membrane electrodialysis (BPMED) stack arranged in stack direction between the cathode and the anode. The BPMED stack typically comprises at least one bipolar membrane. In preferred embodiments, the BPMED stack comprises a plurality of a least two bipolar membranes. In at least some embodiments, the BPMED stack comprises a plurality of at least two bipolar membranes, wherein at least one bipolar membrane of the plurality of bipolar membranes faces the cathode and at least one bipolar membrane of the plurality of bipolar membranes faces the anode.

[0153] In some embodiments, a two-compartment BPMED unit or a three-compartment BPMED unit may be used. Depending on the application, either a three-compartment BPMED unit or a two-compartment BPMED unit may be more desirable. The inventors have found that using a two-compartment BPMED unit is particularly advantageous in the process described herein because it was found to minimize electrical resistance and energy consumption, thereby enhancing energy efficiency. In particular, the energy required for pH adjustments could be reduced.

[0154] As the skilled person knows, three-compartment BPMED units include an anion-exchange membrane and a cation-exchange membrane arranged between two consecutive bipolar membranes in the stacking direction, thereby forming three compartments between the respective two consecutive bipolar membranes. In at least some embodiments, the three-compartment BPMED unit comprises a BPMED stack having the following configuration in the stack direction: [BPM-AEM-CEM]n-BPM, wherein BPM is a bipolar membrane, AEM is an anion-exchange membrane, CEM is a cationic exchange membrane and n is an integer selected from 1 or more. It is understood that the expression [,..]nindicates a repeating unit which is repeated n times in the stack direction. It isP29247PC00 March 2026

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[0156] also understood that the BPMED stack may include further components, such as spacers, sealing gaskets, etc.

[0157] As the skilled person knows, two-compartment BPMED units include either an anion-exchange membrane or a cation-exchange membrane arranged between two consecutive bipolar membranes in the stacking direction, thereby forming two compartments between the respective two consecutive bipolar membranes. In preferred embodiments, the two-compartment BPMED unit as used in the process or apparatus disclosed herein includes an anion-exchange membrane arranged between two consecutive bipolar membranes in the stacking direction, thereby forming two compartments between the respective two consecutive bipolar membranes. In at least some embodiments, the two-compartment BPMED unit comprises a BPMED stack having the following configuration in the stack direction: [BPM-AEM]n-BPM, wherein BPM is a bipolar membrane, AEM is an anion-exchange membrane and n is an integer selected from 1 or more. It is understood that the expression [,..]nindicates a repeating unit which is repeated n times in the stack direction. It is also understood that the BPMED stack may include further components, such as spacers, sealing gaskets, etc.

[0158] In a further optimization of the process described herein, the inventors found that performing the electrodialysis treatment at a current density in a range from 10 mA / cm2to 30 mA / cm2, preferably from 10 mA / cm2to 22 mA / cm2is particularly advantageous, e.g. because it leads to high levels of carbon dioxide removal and high energy efficiency. Thus, in some embodiments, the electrodialysis treatment is performed at a current density in a range from 10 mA / cm2to 22 mA / cm2. In certain embodiments, it may be beneficial to perform the electrodialysis treatment at a current density in a range from 12 to 30 mA / cm2, e.g. from 12 to 22 mA / cm2, preferably from 15 to 22 mA / cm2.

[0159] The current densities described yield particularly good results when used in combination with a three-compartment BPMED unit. Thus, in some embodiments, the electrodialysis treatment is performed using a three-compartment BPMED unit and at a current density in a range from 10 mA / cm2to 30 mA / cm2, preferably from 10 mA / cm2to 22 mA / cm2. In certain embodiments, it may be advantageous to use the described current densities in combination with a two-compartment BPMED unit. For example, in some embodiments, the electrodialysis treatment is performed using a two-compartment BPMED unit and at a current density in a range from 10 mA / cm2to 30 mA / cm2, preferably from 12P29247PC00 March 2026

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[0161] mA / cm2to 22 mA / cm2, more preferably from 15 mA / cm2to 22 mA / cm2. These embodiments are particularly advantageous when also using a liquid capture solvent comprising PEI, preferably PEI having a molecular weight in a range from 1000 Da to 5000 Da, particularly from 1500 Da to 4000 Da, more particularly from 2500 Da to 3500 Da. In some embodiments, the C02-loaded capture solvent is passed through the electrodialysis unit at a flow rate in a range from 10 l / h to 200 l / h, preferably in a range from 30 l / h to 100 l / h, more preferably in a range from 30 l / h to 50 l / h.

[0162] Depending on the application, different current densities may be used. For example, in some embodiments, the electrodialysis treatment is performed at a current density in a range from 10 mA / cm2to 30 mA / cm2. However, in other embodiments, the electrodialysis treatment may be performed at a current density up to 300 mA / cm2, e.g. from 10 to 300 mA / cm2, for example from 100 to 200 mA / cm2. Depending on the application and on a membrane surface area of the ion exchange membrane (e.g. in particular AEM), the current densities may differ for different scales. Thus, in at least some embodiments, a current density applied during the electrodialysis treatment is in a range from 10 mA / cm2to 30 mA / cm2per m2of membrane surface area of the ion exchange membrane. However, in other embodiments, a current density applied during the electrodialysis treatment is in a range up to 300 mA / cm2, e.g. from 10 to 300 mA / cm2, for example from 100 to 200 mA / cm2, per m2of membrane surface area of the ion exchange membrane.

[0163] Carbon Dioxide Release Unit

[0164] In preferred embodiments, the method disclosed herein further comprises the step of releasing, in a carbon dioxide release unit, carbon dioxide from the release solution. For example, the release solution may continuously cycle between the electrodialysis unit and the carbon dioxide release unit.

[0165] Preferably, the carbon dioxide release unit comprises a hydrophobic hollow fiber membrane. It is understood that the hydrophobic hollow fibre membrane is gas permeable, in particular carbon dioxide permeable. The use of a hollow fiber membrane ensures efficient CO2release while enabling solvent reuse and maintaining thermodynamic equilibrium.P29247PC00 March 2026

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[0167] In preferred embodiments, the step of releasing the carbon dioxide from the release solution is performed at a pH of less than 8.0, preferably from 4.0 to 7.5. Alternatively or in combination, in some embodiments, the step of releasing the carbon dioxide from the release solution is performed at a pressure of less than 500 mbar, preferably at a pressure of less than 200 mbar, e.g. at a pressure from 60 mbar to 120 mbar. These conditions were found optimal for efficient carbon dioxide removal at reasonable energy consumption.

[0168] Apparatus

[0169] In a second aspect, the present invention provides an apparatus for capturing CO2from a C02-containing gas mixture. The assembly comprises:

[0170] - a contactor configured to contact the C02-containing gas mixture with a liquid capture solvent;

[0171] - a first conduit fluidically interconnecting a first outlet of the contactor with a first inlet of an electrodialysis unit;

[0172] - an electrodialysis unit configured for subjecting a C02-loaded capture solvent to an electrodialysis treatment, thereby obtaining a regenerated liquid capture solvent;

[0173] - A second conduit fluidically interconnecting a first outlet of the electrodialysis unit with a first inlet of the contactor and configured for supplying the regenerated liquid capture solvent from the electrodialysis unit to the contactor.

[0174] The electrodialysis unit typically comprises an ion exchange membrane configured to be contacted with the C02-loaded capture solvent during the electrodialysis treatment. For example, the electrodialysis unit may comprise an anion-exchange membrane.

[0175] The term conduit as used herein generally refers to a guiding structure for guiding liquids, in particular for guiding the capture solvent. A given conduit may for example comprise piping, but other liquid guiding structures may also be used.

[0176] In preferred embodiments, the apparatus is configured to perform the process according to any of the embodiments described herein.P29247PC00 March 2026

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[0178] In preferred embodiments, the method disclosed herein is performed using the apparatus disclosed herein.

[0179] The embodiments described herein in the context of the process of the first aspect are also embodiments of the apparatus of the second aspect. In particular, among other embodiments, the embodiments of the contactor, the first conduit, the electrodialysis unit, the capture solvent and the upgrading unit, which are described herein in the context of the process of the first aspect, are also embodiments of the apparatus of the second aspect. The same applies vice versa, i.e. the embodiments described herein in the context of the apparatus of the second aspect are also embodiments of the process of the first aspect.

[0180] As described above, the electrodialysis unit is configured for subjecting a C02-loaded capture solvent to an electrodialysis treatment. It is understood that this C02-loaded capture solvent is obtained in the contactor by contacting the C02-containing gas mixture with the liquid capture solvent. It is also understood that this C02-loaded capture solvent comprises bicarbonate ions and / or carbonate ions. It is also understood that, in addition to the C02-loaded capture solvent, a CO2-depleted gas stream is also obtained in the contactor.

[0181] The contactor therefore typically comprises a second contactor outlet for outlet of the CO2-depleted gas stream.

[0182] In preferred embodiments, the apparatus further comprises a load level checkpoint unit arranged with respect to a direction of flow of the capture solvent between the contactor and the electrodialysis unit. The load level checkpoint unit may further be fluidically interconnected through a bypass conduit with a second inlet of the contactor. The bypass conduit bypasses the electrodialysis unit.

[0183] In some embodiments, for example, the first conduit may fluidically interconnect the first outlet of the contactor with the first inlet of the electrodialysis unit through intermediacy of the load level checkpoint unit. As an example, at least a section of the first conduit may e.g. fluidically interconnect a first outlet of the load level checkpoint unit with the first inlet of the electrodialysis unit. The load level checkpoint unit may then e.g. be arranged at the first outlet of the contactor, or a further section of the first conduit may fluidically interconnect the first outlet of the contactor with an inlet of the load level checkpoint unit.P29247PC00 March 2026

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[0185] In some embodiments, the apparatus comprises a bypass conduit fluidically interconnecting a second outlet of the load level checkpoint unit with a second inlet of the contactor. The bypass conduit bypasses the electrodialysis unit. Preferably, the bypass conduit fluidically interconnects the second outlet of the load level checkpoint unit with the second inlet of the contactor directly.

[0186] The load level checkpoint unit is configured for determining a load level of the CO2-loaded capture solvent. The load level checkpoint unit is further configured to:

[0187] - Supply the C02-loaded capture solvent to the electrodialysis unit (e.g. through at least a section of the first conduit) for electrodialysis treatment if the determined load level exceeds a target minimum load level;

[0188] - Recycle at least a bypass portion of the C02-loaded capture solvent to the contactor (preferably through the bypass conduit), bypassing the electrodialysis unit, if the determined load level does not exceed the target minimum load level. Further embodiments of the target minimum load level and of the load level checkpoint respectively the load level checkpoint unit are described above and are also embodiments of the apparatus.

[0189] In some embodiments, the contactor comprises at least a first contactor section and a second contactor section, each configured for contacting the C02-containing gas mixture with the liquid capture solvent. In these embodiments, the load level checkpoint unit is preferably configured for:

[0190] - determining a first load level of a first C02-loaded capture solvent fraction obtained from the first contactor section, and a second load level of a second CO2- loaded capture solvent fraction obtained from the second contactor section; and for

[0191] - determining, by comparing the first load level and the second load level, a lower loading efficiency contactor section corresponding to one of the first and second contactor section, and a higher loading efficiency contactor section corresponding to the other of the first and second contactor section.P29247PC00 March 2026

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[0193] In some embodiments, the load level checkpoint unit is further configured, if the determined first load level and the determined second load level do not exceed the target minimum load level, for:

[0194] - Recycling the C02-loaded capture solvent fraction for which a lower load level was determined to the higher loading efficiency contactor section, bypassing the electrodialysis unit; and

[0195] - Recycling the other of the first and second C02-loaded capture solvent fraction for which a higher load level was determined to the lower loading efficiency contactor section, bypassing the electrodialysis unit.

[0196] Additionally or alternatively to the embodiments described in the previous sentence, in some embodiments, the load level checkpoint unit is further configured, if the determined first load level does not exceed the target minimum load level and the determined second load level exceeds the target minimum load level, for:

[0197] - Recycling at least a first bypass portion of the first C02-loaded capture solvent fraction to the higher loading efficiency contactor section (e.g. through the bypass conduit), bypassing the electrodialysis unit; and

[0198] - Supplying the second C02-loaded capture solvent fraction to the electrodialysis unit for electrodialysis treatment.

[0199] It is to be understood that both the foregoing general description and the following detailed description present embodiments and are intended to provide an overview or framework for understanding the nature and character of the disclosure. In the description, reference is made to the accompanying drawings, which form a part hereof and in which there is shown byway of illustration, not limitation, embodiments of the disclosure. The description of preferred embodiments is not intended to limit the disclosure to cover all modifications, equivalents and alternatives. Reference should therefore be made to the claims recited herein for interpreting the scope of the disclosure.P29247PC00 March 2026

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[0201] BRIEF DESCRIPTION OF THE DRAWINGS

[0202] The present disclosure will be more fully understood from the detailed description provided hereinbelow and the accompanying figures, which should not be considered limiting to the disclosure described in the appended claims.

[0203] Fig. 1 an embodiment of the apparatus described herein;

[0204] Fig. 2 an embodiment of an electrodialysis unit that may be used in the process and apparatus described herein;

[0205] Fig. 3 shows a comparison of the time dependent pH curve of absorption of pure carbon dioxide into different capture solvents;

[0206] Fig. 4 shows a comparison of the time dependent pH curve of absorption of carbon dioxide from air into different capture solvents;

[0207] Fig. 5 show a comparison of the time dependent carbon dioxide absorption curves of pure carbon dioxide for different capture solvents;

[0208] Fig. 6 show a comparison of the time dependent carbon dioxide absorption curves of carbon dioxide from air for different capture solvents;

[0209] Fig. 7 shows a comparison of the carbon dioxide loading at different pH values for different capture solvents;

[0210] Fig. 8 illustrates the energy consumption in dependence of the load level of the capture solvent for the electrodialysis unit (top graph), the conctactor (middle graph) and the overall process (bottom graph).

[0211] DETAILED DESCRIPTION

[0212] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, theseP29247PC00 March 2026

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[0214] embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0215] Process Diagram and Apparatus

[0216] Figure 1 shows an embodiment of the apparatus 1 described herein. It highlights the key components and their interactions, including the liquid air contactor, cell stacks, and supporting systems.

[0217] The main equipment of the apparatus includes an air contactor 2, an electrodialysis unit 4, and a carbon dioxide release unit (degasser) 101.

[0218] Air Contactor 2: An air fan directs the atmospheric air stream (optionally pressurized through pressurizer 8) into a structured contactor 2, ensuring sufficient pressure to overcome the contactor pressure drop. Inside the contactor 2, the air encounters an evenly distributed liquid capture solvent delivered by a liquid distribution system. The structured packing material is designed to maximize the liquid film surface area while minimizing airflow resistance. As the air passes through, the continuously recirculating alkaline solvent reacts with CO2, forming bicarbonate and carbonate compounds.

[0219] Electrodialysis unit 4: The purpose of the electrodialysis (ED) unit 4 is to transfer ions of interest from the basic loop to the acidic loop. This is achieved by applying an electric voltage, which drives ions through selectively permeable stacked membranes, called BPMED, based on their charge. The BPMED (Bipolar Membrane Electrodialysis) unit comprises a cathode chamber and an anode chamber.

[0220] Furthermore, two compartments are arranged between the first electrode 431 and the second electrode 432. More specifically, an acid compartment and an alkaline compartment are formed.

[0221] The anode and cathode chambers are isolated from the main process flow. To protect the electrodes, an Electrode Rinse Solution (ERS) from circulates through these chambers (not shown). This solution, typically composed of K2SO4, is used for electrode protection.P29247PC00 March 2026

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[0223] The acid and base compartments are separated by ion exchange membranes. A polymeric amine, which may e.g. be too large to pass through the Anion-Exchange Membrane (AEM), is directed into the base chamber for pH regeneration. The BPMED stack features multiple chambers separated by bipolar membranes. In a two-compartment setup, as illustrated, the carbon dioxide loaded capture solvent flows through a first inlet 411 of the electrodialysis unit 4 into the basic chamber, while a desorption buffer solution enters the acid chamber of the electrodialysis unit through a second inlet 412.

[0224] On the acidic side, the H+ ions lower the pH, converting bicarbonate (HCO3“) into dissolved CO2by shifting the equilibrium:

[0225] HCO3- + H+^CO2(,g) + H2O

[0226] Simultaneously, the alkaline side accumulates OH“ ions, maintaining a high pH for regenerating bicarbonate in the solution.

[0227] Degasser 101: The degasser 101 is responsible for extracting pure CO2from the acidic loop for subsequent storage or utilization (which may e.g. involve pressurization in a carbon dioxide pressurizer 9 followed by bottling of the carbon dioxide). This process relies on the principle of gas-liquid equilibrium, where dissolved CO2in the acidic solution is released when exposed to a lower pressure environment. To achieve this, a gas-liquid degassing contactor 101 is installed, downstream of the ED stack. The contactor provides a large surface area for mass transfer, allowing dissolved CO2to escape from the liquid phase into the gas phase. This separation is enhanced by a vacuum pump, which reduces the pressure inside the contactor, driving CO2desorption from the acid stream. By maintaining a controlled vacuum level, the system ensures efficient CO2removal while minimizing energy consumption. The extracted CO2is then directed for storage or further utilization, while the degassed liquid continues through the process.

[0228] The CO2is retrieved by leveraging a gas-permeable, hydrophobic hollow fiber membrane to remove dissolved gases from liquids in combination of mild vacuum (60-100 mbar). The mechanism relies on Henry's Law: gases in the liquid phase pass through the membrane pores under a pressure gradient created by a vacuum, while the liquid is retained.P29247PC00 March 2026

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[0230] Bipolar Membrane Electrodialysis Unit

[0231] Figure 2 showsan embodiment of an electrodialysis unit that may be used in the process and apparatus described herein. The electrodialysis unit is a two-compartment (i.e. two-chamber) electrodialysis unit. It comprises two oppositely arranged electrodes and a stack of membranes arranged in stacking direction between the electrodes. More specifically, it comprises a first bipolar membrane (BPM) facing a first electrode and a second bipolar membrane (BPM) facing a second electrode. Furthermore, an anion-exchange membrane (AEM) is arranged between the first and second BPM. As illustrated in Fig. 2, the electrodialysis unit may include a repeat unit, i.e. it may arranged multiple BPM-AEM pairs behind each other in stacking direction.

[0232] During the process described herein, the carbon dioxide loaded capture solvent may be supplied to a first compartment arranged between the first BPM and the AEM. More specifically, the first compartment is arranged on a side of the AEM that faces the negatively charged electrode. Concurrently, a release solution is supplied during operation to a second compartment arranged on an opposite side of the AEM, i.e. between the AEM and the subsequent BPM. During operation, bicarbonate ions pass in direction of the applied electric potential from the first compartment through the AEM into the second compartment, i.e. from the carbon dioxide loaded capture solvent to the release solution. Concurrently, hydroxide anions pass from the first BPM into the first compartment, thereby compensating the departing bicarbonate ions and increasingly basifying the carbon dioxide loaded capture solvent. Importantly, the non-ionic components of the carbon dioxide loaded capture solvent stay inside the first compartment and thus in the capture solvent. Thereby, the liquid capture solvent is increasingly regenerated and ultimately flows out of the electrodialysis unit, to be supplied to the contactor again. At the same time, the release solution is increasingly loaded with bicarbonate ions and / or carbon dioxide (in a pH-dependent equilibrium) and is finally cycled from the electrodialysis unit to a carbon dioxide release unit (e.g. a degasser), as illustrated in Fig. 1.P29247PC00 March 2026

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[0234] Study of Absorption Step

[0235] Figures 3-7 show the results of a study of the absorption step in which different capture solvents were analyzed. The different analyzed capture solvents are water based and include:

[0236] - 1 M KOH;

[0237] - 5 wt.-% polyethylene imine (PEI) having a weight average molecular weight (Mw) of 800 g / mol;

[0238] - 5 wt.-% PEI having a molecular weight of 3000 g / mol;

[0239] - A mixture of 5 wt.-% PEI having a molecular weight of 800 g / mol and 0.5 M KOH; - A mixture of 5 wt.-% PEI having a molecular weight of 3000 g / mol and 0.5 M KOH.

[0240] In Figs. 3-4, the capture step was tracked over time by monitoring the change pH of the different capture solvents over time. In Fig. 3, pure carbon dioxide was used, while in Fig. 4, air was used.

[0241] Unsurprisingly, changes in pH were observed more rapidly when using pure carbon dioxide compared to air. Interestingly, the drop in pH appeared to occur more quickly when using 800 Da PEI compared to 3000 Da PEI when used in the presence of KOH and together with pure carbon dioxide, but this difference vanished in the absence of KOH (Fig. 3). Turning to capturing carbon dioxide from air (Fig. 4), 3000 Da PEI showed a slightly lower pH overtime than 800 Da PEI, which could possibly be due to a slight initial difference in pH between 800 Da and 3000 Da PEI. Fig. 4 demonstrates that using 3000 Da PEI allows reaching more acidic pH values more quickly compared to using 800 Da PEI. This is advantageous also when considering that the electrodialysis step performs better at more acidic pH values.

[0242] The differences between the solvents in carbon dioxide loading over time were more pronounced (Figs.5 and 6). More specifically, the loading profile was measured for loading from pure carbon dioxide (Fig. 5) and from air (Fig. 6). For loading from pure carbon dioxide (Fig. 5), the purely PEI-based capture solvents (i.e. in the absence of additional KOH) demonstrated both slower loading over time and reached a lower plateau moreP29247PC00 March 2026

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[0244] quickly compared to those capture solvents which also contain KOH. For the KOH-con-taining capture solvents, the molecular weight of PEI did not have a great influence, possibly due to the fact that the properties of the capture solvent are dominated by KOH. However, in the absence of KOH, it was surprising to find that using 800 Da PEI demonstrated quicker carbon dioxide loading and higher loading levels at each point in time than using 3000 Da PEI. The superior capture performance of 800 Da PEI was also observed when capturing carbon dioxide from air (Fig. 6).

[0245] On the face of it, these results may be read as suggesting that a KOH-containing capture solvent including 800 Da PEI is best for absorption. However, simply optimizing for the absorption step in isolation may be misguided and may not lead to optimal overall process conditions. Specifically, for example, while KOH may be advantageous for the capture step, adding KOH would also significantly increase the pH. This means that if a given target pH is to be reached for the subsequent electrodialysis step, the KOH-based capture solvent would need to be passed through the contactor for a significantly longer time until it finally reaches the desired target pH for the electrodialysis step.

[0246] For example, Fig. 7 illustrates the carbon loading of the different capture solvents at different pH values. The figure illustrates that the carbon loadings are significantly higher at each given pH for a KOH-based capture solvent. However, this also means that it takes significantly longer until the KOH-based capture solvents, which typically have an initial pH of above 13.5, reach a pH of 11 or less, or even 10 or less. Crucially, on the way to reaching a pH of 11 or less, the KOH-based capture solvents need to pass through a plateau (ca. pH 11-13) in which no additional carbon dioxide is captured but in which essentially only acidification takes place.

[0247] By contrast, the PEI-based capture solvents display a much more favorable pH profile: To start with, the PEI-based capture solvents have a more favorable initial pH range. Additionally, the envisioned pH range within which the PEI-based capture solvents would cycle lies in the steepest part of the curve. In other words, the most capture-efficient pH range of the PEI-based solvents would be exploited (cf. dashed box in Fig. 7). Within this window, surprisingly, using 3000 Da PEI was found to be more advantageous when optimizing for rapidly achieving a lower pH. By contrast, 800 Da PEI could be used for achieving higher carbon dioxide loadings at a given pH. Thus, the molecular weight of PEI can be tailored for the specific needs of a given process.P29247PC00 March 2026

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[0249] Figure 8 illustrates the results of measurements concerning the energy efficiency of the process of the present disclosure. Specifically, the figure shows the energy consumption (per mol of CO2) in dependence of the load level of the capture solvent for the electrodialysis unit (top graph), the conctactor (middle graph) and the overall process (bottom graph). It is understood that the same x-axis (i.e. load level) applies to all three graphs, which is why the graphs are illustrated stacked on top of each other.

[0250] The x axis commences at a load level of 0 (i.e. fresh capture solvent) and spans to a saturation point (abbreviated in Fig. 8 as “satur.”) at which the C02-loaded capture solvent is fully saturated and cannot be loaded with any more CO2.

[0251] The energy consumption of two different components of the process were measured in isolation (namely the electrodialysis unit and the contactor), and then the energy consumption of the overall process was measured.

[0252] The measurements showed that the electrodialysis step is energy inefficient at low load levels, and gradually becomes increasingly energy efficient as the capture solvent is increasingly loaded. The highest energy efficiency is reached when the C02-loaded capture solvent is fully saturated.

[0253] By contrast, the contactor has a competing, non-aligned energy efficiency profile: The contactor operates with the highest energy efficiency at low load levels, and the energy inefficiency increasingly drops (i.e. the energy consumption increasingly rises) as the load level increases.

[0254] Finally, the energy efficiency of the overall process was measured. It should be noted that the overall process energy profile is not simply a sum of the electrodialysis unit and the contactor, in part because there are also other components to the overall process. The measurements for the overall process showed that the energy consumption initially drops as the solvent becomes increasingly saturated. Interestingly, however, the energy consumption does not steadily decrease towards the saturation point. Instead, a local minimum is reached (i.e. a window of lowest energy consumption, i.e. highest energy efficiency), and once the C02-loaded capture solvent is almost fully saturated, the energy efficiency increases again towards full saturation. In other words, the measurements showed that there is an optimal window within which the overall process operates mostP29247PC00 March 2026

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[0256] energy-efficiently, and this window is located between a target minimum load level (abbreviated in Fig. 8 as “Target(min)”) and a target maximum load level (abbreviated in Fig.

[0257] 8 as “Target(max)”).

[0258] The measurement results are considered surprising because it may have been expected that the electrodialysis step itself dictates the energy efficiency of the overall process because electrodialysis is traditionally thought of as being relatively energy intensive compared to e.g. the contacting step or other steps in carbon capture processes.

[0259] The measurement findings can be used to operate the process of the present disclosure with high energy efficiency, as explained in the present disclosure. For example, the target minimum load level may be ensured by only passing the C02-loaded capture solvent to the electrodialysis unit once it has reached the target minimum load level as described herein.

[0260] Furthermore, the target maximum load level may be implemented by operating the contactor such that the C02-loaded capture solvent leaving the contactor is not fully satu-rated but instead has a load level up to the target maximum load level. Should the measured load level of the C02-loaded capture solvent leaving the contactor exceed the target maximum load level, at least one control parameter for the contacting step may be changed, such that the load level of the C02-loaded capture solvent obtained from the contactor in a subsequent repetition of step is reduced.P29247PC00 March 2026

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[0262] LIST OF DESIGNATIONS 101 carbon dioxide release unit

[0263] 1 Apparatus

[0264] 2 Contactor

[0265] 21 first inlet of contactor

[0266] 22 second inlet of contactor

[0267] 23 third inlet of contactor

[0268] 24 first outlet of contactor

[0269] 25 second outlet of contactor

[0270] 3 first conduit

[0271] 4 electrodialysis unit

[0272] 411 first inlet of electrodialysis unit

[0273] 412 second inlet of electrodialysis

[0274] unit

[0275] 421 first outlet of electrodialysis unit

[0276] 422 second outlet of electrodialysis

[0277] unit

[0278] 431 first electrode

[0279] 432 second electrode

[0280] 441 bipolar membrane

[0281] 442 anion-exchange membrane

[0282] 5 second conduit

[0283] 6 load level checkpoint

[0284] 61 load level checkpoint unit

[0285] 7 bypass conduit

[0286] 8 air inlet pressurizer

[0287] 9 carbon dioxide pressurizer

[0288] 10 upgrading unit

Claims

P29247PC00 March 202637 / 42PATENT CLAIMS1. A process of capturing CO2from a C02-containing gas mixture, the method comprising the steps of:a) Contacting the C02-containing gas mixture in a contactor (2) with a liquid capture solvent, thereby obtaining a CO2-depleted gas stream and a C02-loaded capture solvent comprising bicarbonate ions and / or carbonate ions;b) Supplying the C02-loaded capture solvent to an electrodialysis unit (4); c) Subjecting the C02-loaded capture solvent to an electrodialysis treatment in the electrodialysis unit (4), comprising contacting the C02-loaded capture solvent with an ion exchange membrane, thereby obtaining a regenerated liquid capture solvent; andd) Supplying the regenerated liquid capture solvent from the electrodialysis unit (4) to the contactor (2) for being contacted with the C02-containing gas mixture according to step a).

2. The process of claim 1, further comprising between steps a) and b), the step of determining a load level of the C02-loaded capture solvent at a load level checkpoint (6),Wherein if the determined load level exceeds a target minimum load level, the CO2- loaded capture solvent is supplied to the electrodialysis unit (4) according to step b) for the subsequent electrodialysis treatment according to step c);Wherein if the determined load level does not exceed the target minimum load level, at least a bypass portion of the C02-loaded capture solvent is recycled to the contactor (2), bypassing the electrodialysis unit (4).

3. The process of claim 2, wherein the step of determining the load level of the CO2- loaded capture solvent at the load level checkpoint (6) comprises one or more of the following:determining a total inorganic carbon concentration of the C02-loaded capture solvent;P29247PC00 March 202638 / 42determining a pH of the C02-loaded capture solvent;determining a conductivity of the C02-loaded capture solvent.

4. The process of claim 3, wherein the step of determining the load level of the CO2- loaded capture solvent at the load level checkpoint (6) comprises measuring the conductivity of the C02-loaded capture solvent and then determining the load-level of the C02-loaded capture solvent based only on the measured conductivity as the sole measured parameter for determining the load level.

5. The process of claim 3, wherein the target minimum load level is:Exceeded if the pH of the C02-loaded capture solvent is determined to be lower than a target threshold pH; andNot exceeded if the pH of the C02-loaded capture solvent is determined to be equal to or higher than the target threshold pH;Wherein the target threshold pH is selected to be less than 10.5, preferably in a range from 9.1 to 9.9, more preferably in a range from 9.3 to 9.7.

6. The process of any one of claims 2-5, wherein the bypass portion is recycled to the contactor (2) separately from the regenerated capture solvent.

7. The process of any one of claims 2-6, wherein if the determined load level exceeds a target maximum load level, at least one control parameter for the contacting step a) is changed, such that the load level of the C02-loaded capture solvent obtained from the contactor (2) in a subsequent repetition of step a) is reduced.

8. The process of claim 7, wherein if the determined load level exceeds a target maximum load level, at least one control parameter for the contacting step a) is changed as follows:A flow rate of the C02-containing gas mixture through the contactor (2) in step a) is increased; and / orA flow rate of the liquid capture solvent through the contactor (2) in step a) is increased; and / orP29247PC00 March 202639 / 42An average time of contact between the C02-containing gas mixture and the liquid capture solvent in the contactor (2) in step a) is decreased; and / or A pH of the liquid capture solvent with which the C02-containing gas mixture is contacted in the contactor (2) in step a) is decreased.

9. The process of any one of claims 2-8, wherein the contactor (2) comprises at least a first contactor section and a second contactor section, wherein in step a) the C02-containing gas mixture is contacted with the liquid capture solvent in the first contactor section and in the second contactor section;Wherein the step of determining the load level of the C02-loaded capture solvent at the load level checkpoint (6) comprises:determining a first load level of a first C02-loaded capture solvent fraction obtained from the first contactor section, and a second load level of a second C02-loaded capture solvent fraction obtained from the second contactor section; anddetermining, by comparing the first load level and the second load level, a lower loading efficiency contactor section corresponding to one of the first and second contactor section, and a higher loading efficiency contactor section corresponding to the other of the first and second contactor section.

10. The process of claim 9, wherein if the determined first load level and the determined second load level do not exceed the target minimum load level:The C02-loaded capture solvent fraction for which a lower load level was determined is recycled to the higher loading efficiency contactor section, bypassing the electrodialysis unit (4); andThe other of the first and second C02-loaded capture solvent fraction for which a higher load level was determined is recycled to the lower loading efficiency contactor section, bypassing the electrodialysis unit (4).P29247PC00 March 202640 / 4211. The process of any one of the previous claims, wherein the step of contacting the C02-containing gas mixture in the contactor with the liquid capture solvent is performed such that the obtained C02-loaded capture solvent has a load level below saturation.

12. The process of any one of the previous claims, wherein the C02-loaded capture solvent that is supplied to the electrodialysis unit in step b) has a load level below saturation.

13. The process of any one of the previous claims, wherein the liquid capture solvent has a pH of 10.0 or higher, preferably from 10.0 to 12.0, more preferably from 10.0 to 11.0, before being contacted with the C02-containing gas mixture in step a).

14. The process of any one of the previous claims, wherein the liquid capture solvent comprises an amine, preferably in an amount of at least 1 wt.-%, more preferably from 2 wt.-% to 20 wt.-%, even more preferably from 3 wt.-% to 10 wt.-%.

15. The process of claim 14, wherein the amine is a polymeric amine, preferably polyethylene imine.

16. The process of claim 15, wherein the polyethylene imine has a molecular weight in a range from 500 Da to 5’000 Da, preferably from 800 Da to 3’000 Da, more preferably a molecular weight of 800 Da or 3’000 Da.

17. The process of any one of the previous claims, wherein the liquid capture solvent comprises a metal carbonate and / or a metal bicarbonate, preferably in a combined concentration of at least 0.1 M, more preferably in a combined concentration from 0.3 M to 3.0 M, even more preferably in a combined concentration from 0.4 M to 2.0 M, such as in a combined concentration from 0.5 M to 0.7 M.

18. The process of claim 17, wherein the liquid capture solvent comprises potassium bicarbonate, preferably in a potassium bicarbonate concentration of at least 0.1 M, more preferably in a potassium bicarbonate concentration from 0.3 M to 3.0 M, even more preferably in a potassium bicarbonate concentration from 0.4 M to 2.0 M, even more preferably in a potassium bicarbonate concentration from 0.5 M to 0.7 M.P29247PC00 March 202641 / 4219. The process of any one of the previous claims, wherein the electrodialysis treatment in step c) comprises contacting the C02-loaded capture solvent with an anion-exchange membrane, to transfer at least some of the bicarbonate ions and / or carbonate ions from the C02-loaded capture solvent through the anion-exchange membrane into a release solution.

20. The process according to any one of the previous claims, wherein the electrodialysis unit (4) is a bipolar membrane electrodialysis (BPMED) unit.

21. The process according to claim 20, wherein the bipolar membrane electrodialysis unit is a two-compartment BPMED unit.

22. The process according to claim 20, wherein the bipolar membrane electrodialysis unit is a three-compartment BPMED unit.

23. The process according to any one of claims 20-22, wherein the electrodialysis treatment is performed at a current density in a range from 10 mA / cm2to 30 mA / cm2, preferably from 10 mA / cm2to 22 mA / cm2.

24. The process according to any one of claims 20-23, wherein the C02-loaded capture solvent is passed through the electrodialysis unit (4) at a flow rate in a range from 10 l / h to 200 l / h, preferably in a range from 30 l / h to 100 l / h, more preferably in a range from 30 l / h to 50 l / h.

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