NL2025044B1

NL2025044B1 - Electrochemical device, system and method for electrochemically recovery and/or regeneration of carbon dioxide from a stream

Info

Publication number: NL2025044B1
Application number: NL2025044A
Authority: NL
Inventors: Alessandro Tedesco Michele; Shu Qingdian; Victor Marie Hamelers Hubertus
Original assignee: Stichting Wetsus European Centre Of Excellence For Sustainable Water Tech
Priority date: 2020-03-04
Filing date: 2020-03-04
Publication date: 2021-10-14
Also published as: WO2021177823A1

Abstract

The invention relates to an electrochemical device, system and method for electrochemically recovery and/or regeneration of carbon dioxide (C02) from a stream, such as a regeneration solution from an ion exchange resin bed. The electrochemical device according to the invention comprises: ? an electrochemical device housing comprising: ? an anode compartment, provided With at least one anode compartment inlet that is configured for providing a liquid and/or gas to the anode compartment; ? a cathode compartment, provided With at least one cathode compartment inlet that is configured for providing a liquid and/or gas to the cathode compartment, and provided With at least one cathode compartment outlet that is configured for removing a liquid and/or gas from the cathode compartment; and ? an intermediate compartment, provided between the anode compartment and the cathode compartment, provided With at least one intermediate compartment inlet that is configured to provide the stream to the intermediate compartment, and at least one intermediate compartment outlet; ? an electrode assembly operatively connecting the anode compartment and the cathode compartment, and comprising at least one anode and one cathode; ? a power supply, to provide electricity to the electrode assembly; and ? a C02 gas-liquid separator, Wherein the C02 gas-liquid separator is operatively coupled With the intermediate compartment outlet and the cathode compartment inlet.

Description

ELECTROCHEMICAL DEVICE, SYSTEM AND METHOD FOR ELECTROCHEMICALLY RECOVERY AND/OR REGENERATION OF CARBON DIOXIDE FROM A STREAM The present invention relates to an electrochemical device, system and method for electrochemically recovery and/or regeneration of carbon dioxide (CO») from a stream, such as a regeneration stream from an ion exchange resin bed.

Recovery and/or regeneration of CO, from a stream is often performed using temperature swings, pressure swings, moisture swings and/or pH swings. Especially in case of recovery and/or regeneration from an ion exchange resin bed, the resin is treated too harsh and therefore a limited life time is achieved.

Conventional devices, systems, and/or methods using for example temperature swings, pressure swings, moisture swings and/or pH swings for the recovery and/or regeneration of CO, show degradation of the used resin as the resins are not stable at high temperatures. In practical applications this significantly reduces efficiency and purity opportunities, thereby increasing the {5 operating costs.

Additional problems occur for so-called degraded resins that may block the ion exchange resin bed and/or contaminate the stream, such as a fluid stream, thereby optionally leading to (additional) fouling of the ion exchange resin bed.

These problems prevent an efficient and effective recovery and/or regeneration of CO, from a stream, such as a regeneration stream from an ion exchange resin bed. This problem is even bigger for large scale applications.

The present invention aims at obviating or at least reducing one or more of the aforementioned problems and to enable efficient and effective recovery and/or regeneration of CO,.

This objective is achieved with the electrochemical device for electrochemically recovery and/or regeneration of carbon dioxide (CO:) from a stream, such as a regeneration solution from an ion exchange resin bed, comprising: ~ an electrochemical device housing comprising: — an anode compartment, provided with at least one anode compartment inlet that is configured for providing a liquid and/or gas to the anode compartment; -— a cathode compartment, provided with at least one cathode compartment inlet that is configured for providing a liquid and/or gas to the cathode compartment, and provided with at least one cathode compartment outlet that is configured for removing a liquid and/or gas from the cathode compartment; and

— an intermediate compartment, provided between the anode compartment and the cathode compartment, provided with at least one intermediate compartment inlet that is configured to provide the stream to the intermediate compartment, and at least one intermediate compartment outlet; — an electrode assembly operatively connecting the anode compartment and the cathode compartment, and comprising at least one anode and one cathode; — a power supply, to provide electricity to the electrode assembly; and — a CO: gas-liquid separator, wherein the CO, gas-liquid separator is operatively coupled with the intermediate compartment outlet and the cathode compartment inlet.

In the case of component recovery, for example carbon dioxide recovery and/or regeneration, involving the electrochemical device according to the present invention, the term “carbon dioxide” will be understood as CO: (for example in the gas phase (g) or in solution {ag)). The term “hydrogen (H,) recovery and/or regeneration” will be understood as the recovery and/or regeneration of hydrogen.

For the sake of clarity, in this invention the regeneration solution can also be an electrolyte.

Streams, such as a regeneration stream from an ion exchange resin bed comprises CO., for example dissolved CO: and/or CO, analogues, such as (bi)carbonate ions, more specific sodium bicarbonate (NaHCO; (aq)) and/or sodium carbonate (NaCO: (ag)).

The electrochemical device according to the present invention comprises an electrochemical device housing, wherein the electrochemical device housing comprises a number of compartments. In one of the presently preferred embodiments the electrochemical device housing comprises at least three compartments, i.e. an anode compartment that is provided with at least one anode compartment inlet, a cathode compartment that is provided with at least one cathode compartment inlet and at least one cathode compartment outlet, and an intermediate compartment that is provided between the anode compartment and the cathode compartment and is provided with at least one intermediate compartment inlet and with at least one intermediate compartment outlet.

The at least one anode compartment inlet is configured for providing a liquid and/or a gas to the anode compartment. In a presently preferred embodiment of the invention the at least one anode compartment inlet is operatively connected to the cathode compartment. This connection enables introduction of Ha that is produced in the other compartment(s) into the anode compartment, more specifically this connection allows for H; recycling. In such presently preferred embodiments the at least one anode compartment inlet is operatively coupled with the at least one cathode compartment outlet, preferably via a coupling, pipe and/or tubing.

The at least one cathode compartment inlet is configured for providing a liquid and/or gas to the cathode compartment and operatively connects the cathode compartment with the intermediate compartment. This connection between the intermediate compartment and the cathode compartment preferably enables the recycling of washing liquid. Furthermore, the at least one cathode compartment outlet is configured for removing a liquid and/or gas from the cathode compartment. In a further presently preferred embodiment, in operation the at least one cathode compartment outlet can be operatively coupled with the ion exchange resin bed, preferably via a coupling, pipe and/or tubing. It will be understood that the same outlet can be operatively coupled with the anode compartment inlet as well as with the ion exchange resin bed by separating the liquid and/or gas removed via the at least one cathode compartment outlet from the cathode compartment. For example, the cathode compartment outlet is configured for providing a washing solution and/or including the aforementioned recycling of washing liquid.

The at least one intermediate compartment inlet is configured for providing a liquid and/or gas to the intermediate compartment. Furthermore, the at least one intermediate compartment outlet is configured for removing a liquid and/or gas from the intermediate compartment. In one of the presently preferred embodiments the at least one intermediate compartment inlet can be operatively coupled with the ion exchange resin bed, preferably via a coupling, pipe and/or tabing. This enables supply of washing liquid to the intermediate compartment, for example. In a further presently preferred embodiment the at least one intermediate compartment outlet can be operatively coupled with the cathode compartment outlet, preferably via a coupling, pipe and/or tubing.

The electrode assembly is operatively connected with the anode compartment and the cathode compartment. The electrode assembly comprises at least one anode and at least one cathode, wherein in use the at least one anode and the at least one cathode are connected in a circuit. The circuit comprises a power supply to provide electricity to the electrode assembly. It will be understood the presently preferred embodiments could be provided with, but not limited to, capacitive electrodes, platinum electrodes, copper electrodes, and the like or a combination thereof.

The CO, gas-liquid separator is operatively coupled with the intermediate compartment outlet and the cathode compartment outlet. This separates the CO: from the liquid and can be recovered. Preferably, the CO, gas-liquid separator is configured between the at least one intermediate compartment outlet and the at least one cathode compartment inlet.

In a presently preferred embodiment the electrochemical device housing comprises at least one ion-exchange membrane. The at least one ion-exchange membrane is configured for separating at least two of the compartments.

The at least one ion-exchange membrane separating at least two compartments is preferably one or more of the following: a cation exchange membrane (CEM), an anion exchange membrane (AEM), a bipolar exchange membrane (BEM), hydrophobic membrane, a charge mosaic membrane (CMM), a membrane electrode assembly, or a gas diffusion electrode.

In such preferred embodiment, dependent of the type of membranes, different ions are being transported between the compartments. For example, through the membrane assembly this may involve H* (CEM may be involved) that is transferred from anode compartment to intermediate compartment and/or OH (AEM may be involved) that is transferred from cathode (compartment) to an adjacent compartment or at least transferred away from the cathode. Through the CEM metal ions (Lit, Na’, K*, Mg”, Ca?*) or H', are transferred from the anode (compartment) to an adjacent compartment or at least transferred away from the anode.

In a preferred embodiment the intermediate compartment and/or cathode compartment can be referred to as an acidic compartment. An acidic compartment comprises an environment below IO apHof7.

In one of the presently preferred embodiments, the cathode compartment and the intermediate compartment are separated with one or more CEM’s. This enables transport of protons and alkali metals, such as lithium, sodium and potassium between the different compartments. It will be understood that other configurations for the compartments are possible, {5 and some examples of embodiments of the invention having another configuration will be discussed.

In one of the presently preferred embodiments water is reduced to hydrogen at the cathode, and hydrogen is oxidized at the anode. This achieves a stable operation of the electrochemical device according to this embodiment of the invention. Furthermore, the rate of recovery and/or regeneration of CO: can be controlled with a current.

Below, an example of the cathode reaction (hydrogen formation reaction), the anode reaction (hydrogen oxidation reaction) and replacement of the CO; analogues in the intermediate compartment are included.

Cathode reaction - Hydrogen evolution reaction (HER) 2H0 + 2¢" — 20H + H, Anode reaction - Hydrogen oxidation reaction H, — 2H" + 2¢’ Intermediate compartment reaction — replacement of CO, analogues H" + HCO; © H;CO: © H,0 + CO: In this embodiment of the invention, the electrochemical device is used for recovery and/or regeneration of CO, via using a regeneration stream from an ion exchange resin bed. The electrochemical device according to the invention has the advantage that it can provide CO; on demand. For example, horticulture requires specific amounts in order to achieve maximum growth.

The electrochemical device according to the invention comprises a power supply which can supply electricity to the electrochemical device. As a result, the electrochemical device 5 according to the invention provides in-situ generation of hydrogen and (on demand) carbon dioxide gas with a high purity. An advantage is that the hydrogen can be consumed by the anode.

The electrochemical device is preferred over conventional systems. It obviates or at least reduces the reliance on temperature, pressure, moisture and/or pH. In addition, using electricity enables an efficient recovery of CO,, optionally using electricity from sustainable sources, such as solar panels. Furthermore, the device according to the invention enables simultaneous production of CO, and H,. Furthermore, the electrochemical device according to the invention does not rely on the application of a strong base and/or acid which are harmful and hazardous for the environment.

In a preferred embodiment according to the invention, CO, (gas) is adsorbed by the ion exchange resin bed. The adsorbed gas can be recovered and/or regenerated by regeneration with a washing solution. The washing solution enables desorption of CO, and/or CO: analogues from the ion exchange resin bed and becomes regeneration solution. After recovery of CO: (gas) from the regeneration solution, the regeneration solution can be regenerated/recycled.

In a further preferred embodiment according to the invention CO, (dissolved in an appropriate solvent) is adsorbed by the ion exchange resin bed. The adsorbed CO, can be recovered and/or regenerated by regeneration with a washing solution. The washing solution enables desorption of CO: and/or CO, analogues from the ion exchange resin bed and becomes regeneration solution. After recovery of CO: (gas) from the regeneration solution, the regeneration solution can be regenerated/recycled.

In a presently preferred embodiment according to the present invention, the electrode assembly comprises a membrane-electrode assembly and/or a gas-diffusion electrode assembly.

By providing such an electrode assembly it is possible to achieve a diffusion pathway that is as short as possible. As a result the protons (H") are readily availably to diffuse away from the anode compartment. Furthermore, such an electrode assembly reduces the leaking of undesired ions, due to the fact that the transport of hydrogen ions is reduced to the minimal distance and the desired reactivity per mole hydrogen is increased. Therefore, the desorption process, and thus the CO, recovery and/or regeneration, benefits from an increased efficiency and effectiveness.

In a further presently preferred embodiment according to the present invention, the intermediate compartment and the anode compartment are separated by the membrane-electrode assembly or the gas-diffusion electrode assembly and/or the intermediate compartment and the cathode compartment are separated by the membrane-electrode assembly or a gas-diffusion electrode assembly.

Providing such an electrode assemble to separate the different compartments, results in an effective transfer of ions and enables an efficient process.

In a further presently preferred embodiment according to the present invention, the electrochemical device further comprises a gas-liquid separator, wherein the gas-liquid separator is operatively coupled with the cathode compartment outlet and the anode compartment inlet, and wherein the separated gas flows to the anode compartment.

In the cathode compartment hydrogen is produced and removed from the cathode compartment. The removed hydrogen is to a large extent dissolved in the washing solution. Preferably, the hydrogen that is produced is to a large extent recycled to the anode compartment.

The gas-liquid separator according to the invention enables an efficient recycling of washing solution. This results in in-situ regeneration of hydrogen and reduces the operating costs of the electrochemical device according to the invention. Furthermore, this enhances the possibility for a modular and flexible device that is relatively easy to upscale to match different capacities.

In a further presently preferred embodiment according to the present invention, the CO, gas-liquid separator further comprises a CO; gas release, wherein the CO, is recovered from the CO, gas-liquid separator as a gas stream with a purity of at least 85%, preferably of at least 90%, and more preferably of at least 95%.

Separating the CO: gas from the stream provides a CO: gas stream at high purity. The gas stream can be collected from the release. The collected gas can be directly and/or indirectly used for {high end) applications such as steel production, plant growth and the like. This renders the electrochemical system according to the invention even more effective. For example, an electrochemical device according to the invention could be provided on site, close to the where the CQO, is needed. Furthermore, operating such an electrochemical device comprises providing a stream comprising CO, or CO, analogues and electricity. Therefore, to operate the electrochemical device requires limited operating handlings.

In a further presently preferred embodiment according to the present invention, the anode compartment of the electrochemical device housing further comprises at least one anode compartment outlet that is configured for removing a liquid and/or gas from the anode compartment.

Providing at least one anode compartment outlet results in that an overload of gas and/or liquid in the anode compartment can be removed from the electrochemical device. This enhances the safety as a safe release of build up pressure is achieved.

In a further presently preferred embodiment according to the present invention, the intermediate compartment comprises an ion exchange resin bed, wherein the ion exchange resin bed preferably is an anion exchange resin bed and/or size exclusion ion exchange resin bed.

The use of an intermediate compartment comprising an ion exchange resin bed enables recovery and/or regeneration of CO: directly from the intermediate compartment. It is shown that this significantly improves the overall efficiency of the reactions that take place in the electrochemical device according to the present invention. Therefore, the efficiency of such electrochemical device is improved due to the use of one or more ion exchange resin beds.

In particularly, the direct contact with the OH generating cathode to release HCO; from the resin, the H" generating anode to convert HCO; in CO, and water, and the additional barrier preventing H loss due to reaction with OH’ improves the efficiency of the electrochemical device.

Furthermore, the efficiency of such an electrochemical device is even further improved due to the use of one ore more anion exchange resin beds. It will be understood it is also possible to use a combination of anion and cation exchange resin beds. Furthermore, this allows for a compact and cost-sensitive device.

In a preferred embodiment the anionic exchange resin comprises a polymeric material. Preferably the anion exchange resin comprises amine functionalized groups, and may be used as solid amine sorbent for CO: capture. Such CO, capture may be performed when a gas stream comprising CO, is provided to the resin. Reaction under dry conditions between amine group and CO, 2R‚R:NH + CO; © (RiR:NH;")(R;R;NCOO) Reaction under humid conditions between amine group and CO, RiR:NH + CO: + H,0 © (R;R.NH, Y(HCO3) RiR:NCOO™ + H;0 > R{R,NH + HCO5 An advantage of a size exclusion ion exchange resin bed is that certain particles/molecules are excluded from binding with the resin depending on the size of the particle/molecule. This prevents contamination of the resin with undesired particles. Such size exclusion ion exchange resin is known from WO 2004011141 AL.

The ion exchange resin bed further is more effective and efficient as compared to most conventional recovery and/or regeneration ion exchange resin beds due to the fact that the provided ion exchange resin bed is exposed to ambient conditions, such as ambient temperature, ambient pressure, ambient pH and the like. Therefore, the degradation rate of the ion exchange resin bed is lower compared to conventionally used ion exchange resin beds.

In a preferred embodiment the compartment comprising the resin and/or ion exchange resin bed is different to the compartment comprising an acidic solution.

In a further presently preferred embodiment according to the present invention, the electrochemical device further comprising at least one bipolar membrane, configured for separating the intermediate compartment into at least two intermediate sub-compartments, wherein the ion exchange resin bed is configured in at least one of the at least two intermediate sub-compartments, and wherein a liquid compartment is configured in at least an other one of the at least two intermediate sub compartments.

Providing at least one bipolar membrane for separating the intermediate compartment results in at least two intermediate sub-compartments and enables to provide a modular and scalable electrochemical device, wherein, for example, multiple sub-compartments perform the intermediate compartment reaction as mentioned above. It is shown that this significantly improves the overall efficiency of the reactions that take place in the electrochemical device according to the present invention. Therefore, the efficiency of such electrochemical device is improved due to the use of one or more bipolar membranes defining at least two intermediate sub-compartments.

In a further presently preferred embodiment according to the present invention, the electrochemical device further comprising an additional hydrogen (Hb) gas and/or nitrogen (N,) gas input, wherein the gas input is configured for providing hydrogen (H,) gas and/or nitrogen (N,) gas to the anode compartment.

The use of additional hydrogen gas and/or nitrogen gas which is provided to the anode compartment results in an increased supply of hydrogen to the anode. The advantage is that hydrogen oxidation at the anode increases. It is shown that this significantly improves the overall efficiency of the reactions that take place in the electrochemical device according to the present invention. It will be understood that the nitrogen gas is inert and acts as a carrier gas. The nitrogen gas and, in the case of an overload, hydrogen can be removed from the anode compartment by the anode compartment outlet.

In a further presently preferred embodiment according to the invention, the stream, such as the regeneration solution, of the electrochemical device comprises a buffer, wherein the buffer is one or more selected from the group of aqueous sodium chloride, aqueous potassium chloride, aqueous potassium phosphate, aqueous sodium phosphate, aqueous sodium acetate, aqueous acetic acid, aqueous boric acid, aqueous citric acid, aqueous phosphoric acid.

An advantage of providing a buffer is that the buffer prevents limitation of the conductivity of the regeneration solution. As a result the conductivity is increased and an efficient and effective electrochemical device is achieved. In order to prevent saturation of the resin by the buffer, a buffer with a large particle size is preferred.

Another advantage is that a buffer influences the pH in both the anode and cathode compartments, thus allowing to increase the current applied to the electrochemical cell.

Furthermore, aqueous sodium chloride may increase the conductivity of the electrochemical device according to the invention. Such conductivity improvement results in a more {energy) efficient electrochemical device.

In a preferred embodiment a weak acid is used as buffer. The buffer has preferably a pKa which is lower than the pKa of HCO; (pKa is approximately 6.37). For example, acetic acid can be used as buffer, as the pKa value is approximately 4.76.

In a further presently preferred embodiment according to the invention, the cathode compartment of the electrochemical device comprises a catalyst, wherein the catalyst is one or more selected from the group of electrochemical catalysts, chemical catalyst, and microbial catalyst.

The use of a catalyst in the cathode compartment results in an increase of the reaction rate of the reaction within the cathode compartment. Therefore, the efficiency of the electrochemical device is increased. Such catalyst can produce hydrocarbons from the captured CO: and the H, from the cathode.

For example, the catalyst can provide a reaction wherein the hydrocarbon is methane. To produce 1 mole of formate, 1 mole of H, and 1 mole of CO, are preferred. To produce 1 mole of methane, 4 mole of H, and 1 mole of CO, are preferred. It becomes clear that the gas-liquid separator is redundant.

The chemical catalyst and/or electrochemical catalyst may be based on transition metals, such as Cu, Fe, Co, Ni, Zn, and Pd. Biocatalysts may be acetogenic bacteria, for example selected from the group of Clostridium carboxydivorans, Acetobacterium woodii, or a mixture thereof.

The invention also relates to a system for electrochemically recovery and/or regeneration of carbon dioxide (CO») from a stream, such as a regeneration solution from an ion exchange resin bed, comprising: — an electrochemical device according to the invention; and — an ion exchange resin bed housing, comprising: — anion exchange resin bed; ~ at least one ion exchange resin bed fluid inlet that is configured for providing a fluid to the ion exchange resin bed, such as a washing solution and/or solvent comprising CO:; — at least one ion exchange resin bed gas inlet that is configured for providing a gas comprising CO, such as CO; rich gas, to the ion exchange resin bed; — at least one ion exchange resin bed fluid outlet that is configured for removing a solvent, such as CO; lean solvent and/or regeneration solution, from the ion exchange resin bed; and ~ at least one ion exchange resin bed gas outlet that is configured for removing a gas, such as CO, lean gas, from the ion exchange resin bed.

The system provides the same effects and advantages as those described for the electrochemical device.

The ion exchange resin bed housing comprises an ion exchange resin bed. The ion exchange resin bed housing can be configured outside the electrochemical device in a first embodiment of the invention as well as within an intermediate compartment of the electrochemical device in another embodiment of the invention. For example, in such other embodiment, at least two membranes, preferably at least two anion exchange membranes form side walls of the ion exchange resin bed.

In one of the presently preferred embodiments of the system according to the invention, the system comprises two modules. The first module comprises an electrochemical device according to the invention and the second module comprises an ion exchange resin bed housing that together constitute the system.

The liquid and/or gas stream, for example over the ion exchange resin bed, is flowing preferably from top to bottom. The advantage is that gas bubbles are excluded from the electrochemical device and/or ion exchange resin bed housing. Providing hydrogen to the anode compartment inlet is a stream which flows preferably from bottom to top. This has the advantage that anode compartment is not emptied unexpectedly.

Providing a system comprising at least two modules results in a system wherein the modules can operate independently. This has the advantage that the system is easily scalable and can be adapted to the preferred demand.

Furthermore, a regeneration solution from an ion exchange resin bed can be regenerated by the system according to the invention and used to wash and regenerate the ion exchange resin bed. In a presently preferred embodiment no external sodium hydroxide (NaOH) is supplied to the system while in use. It is shown that this significantly improves the overall efficiency of the reactions that take place in the system according to the present invention. Therefore, the efficiency of such system is improved and operating costs are lowered.

A further advantage is that harsh conditions in respect to the ion exchange resin bed are avoided. It is well known that the degradation rate of ion exchange resin increases with higher temperatures, higher pressures and fluxing pH.

In one of the presently preferred embodiments according to the invention, the ion exchange resin bed comprises an anion exchange resin bed and/or size exclusion ion exchange resin bed.

The use of an anion exchange resin bed shows that the adsorption of carbon dioxide improves the overall efficiency of the reactions that take place in the ion exchange resin.

The use of a size exclusion ion exchange resin bed shows that the adsorption of particles or molecules can be tuned. Particles with a diameter which exceeds the diameter of the pores of the resin are prevented from binding to the resin. As a result, the resin binds the desired particles and the overall efficiency of the reaction that takes place in the ion exchange resin improves compared. to the weight of the resin.

In a further presently preferred embodiment according to the invention, the system further comprises switching means that are configured for switching between a CO; adsorption state and a regeneration state, wherein the system further preferably comprises at least one sensor that is configured for measuring the CO, input and/or H; input and/or CO: output and/or H, output and/or CO, purity.

The use of switching means enables switching between the adsorption state and the desorption state. This has the advantage that the system can be switched between the different states. Furthermore, this enables a modular system, wherein multiple modules are present.

Measuring the CO, input/output and H, input/output enables to monitor the adsorption and IO desorption accurately and had the advantage that switching between the different processes and/or different modules is performed at the best moment, wherein the maximum yield is achieved.

The invention relates to a method for electrochemically recovery and/or regeneration of carbon dioxide (CO,) from a stream, such as a regeneration solution from an ion exchange resin bed, comprising the steps of: — providing an electrochemical device according to the invention and/or system according to the invention; — electrifying the electrochemical device; — providing an regeneration solution to an intermediate compartment; — forming protons (H") in the anode compartment which can be provided to the intermediate compartment; — desorbing CO»; — separating CO, and regeneration solution; — in-situ regenerating of the regeneration solution, preferably forming the washing solution; — separating the regenerated solution and build up hydrogen (Hy) gas: and — in-situ recovering the washing solution.

The method provides the same effects and advantages as those described for the electrochemical device and system.

In one of the presently preferred embodiments according to the method according to the invention, an electrochemical device and/or system according to the invention is provided. The electrochemical device is electrified in order to perform a hydrogen formation reaction at the cathode and hydrogen oxidation reaction at the anode. H' can be formed in the anode compartment, which can be provided to the (adjacent) intermediate compartment. It will be understood that H* formation in the compartment also includes H* formation at the anode.

An advantage of the method according to the invention is that the resin bed may be regenerated via a caustic wash, wherein the caustic solution may be regenerated electrochemically to recover the solvent and pure CO..

In an alternative embodiment the ion exchange resin is provided or loaded/charged within the intermediate compartment of the electrochemical device according to the invention, wherein the formed H© can be provided to the ion exchange resin in the intermediate compartment.

Furthermore, desorbing of CO; in the intermediate compartment is performed to form free CO, and regeneration solution. The (dissolved) CO, and regeneration solution are separated by the CO, gas-liquid separator. The regeneration solution is provided to the cathode compartment, wherein in-situ regenerating of the regeneration solution, preferably forming the washing solution is performed.

Hydrogen gas can be formed in the cathode compartment by the hydrogen formation reaction. An advantage of the hydrogen formation is the formation of hydroxide ions. The hydroxide ions provide in-situ regeneration of the regeneration solution, preferably in-situ recovering of the washing solution in the cathode compartment. The regeneration solution and/or washing solution can be separated by a gas-liquid separator which is operatively connected to the outlet of the cathode compartment.

In one of the presently preferred embodiments according to the invention, the CO, is recovered as gas stream with a purity of at least 85%, preferably of at least 90%, and more preferably of at least 95%.

By recovering CO: as gas stream with a purity of at least 85%, preferably of at least 90%, and more preferably of at least 95% has the advantage that the gas can be used for high end applications, such as steel production, plant growth and the like.

In a further presently preferred embodiment according to the invention, the regeneration solution comprises a wet regeneration solution comprising adsorbed CO,.

Adsorbed CO, comprises bound CO, for example CO, bound to a resin and CO, analogues such as (bi)carbonate ions, more specific sodium bicarbonate (NaHCO; (ag)) and/or sodium carbonate (Na,CO3 (ag)).

An advantage of a wet regeneration solution is that the solution and resin can contain water and drying with for example chemicals such as sodium sulphate and magnesium sulphate or heat is avoided.

In a further presently preferred embodiment according to the invention, the method further comprises the step of providing a gas comprising CO,, such as CO: rich gas, to the system according to the invention, wherein the gas comprising CO, is also referred to as a wet gas comprising COs. The method further comprises the step of removing gas comprising COs, such as CO; lean gas, from the ion exchange resin bed housing from the system according to the invention.

Providing a gas comprising CO; to and removing a gas from the system according to the invention, preferably a gas comprising CO; to an ion exchange resin bed and removing a gas from an ion exchange resin bed enables the electrochemical device and/or system according to the invention to recover and/or regenerate carbon dioxide.

In a further presently preferred embodiment according to the invention, the method further comprises the steps of: ~ flushing the washing solution over the ion exchange resin bed; — regenerating the ion exchange resin bed; and ~ flushing the regeneration solution to the electrochemical device according to the invention.

By flushing the washing solution over the ion exchange resin bed the adsorbed CO, and/or CO, analogue such as carbonate and bicarbonate ions are replaced with anions which are present in the washing solution. Preferably, these anions are hydroxide (OH"). By flushing the washing solution over the ion exchange resin bed, the ion exchange resin bed is simultaneously regenerated.

As a result the ion exchange resin bed can be used multiple times and therefore the operating costs are lowered. Furthermore, performing this method wherein the washing solution is flushed over the ion exchange resin bed and regenerating the ion exchange resin bed provides a method which is more efficient and effective.

In a further presently preferred embodiment according to the invention, the method further comprises the step of providing a fluid through a fluid channel in the intermediate compartment.

Providing a fluid through a fluid channel in the intermediate compartment has shown that the method to operate the electrochemical device and/or system according to the invention enhances the efficiency and effectiveness.

In one of the presently preferred embodiments according to the invention, H; is recycled.

More specifically, H, is recycled between the cathode and anode compartment(s). This provides an effective recovery and/or regeneration of CO,.

In a further presently preferred embodiment of the invention the method comprises the steps of switching switching means and/or measuring the CO, input/output and/or H, input/output and/or CO, purity.

In experiments it was shown that an effective recovery and/or regeneration of CO, is possible, especially from a stream such as a regeneration solution from an ion exchange resin bed.

The electrochemical device, system and method achieve high recovery and/or regeneration rates at low power inputs as compared to conventional carbon dioxide removal processes.

Furthermore, results showed that the electrochemical system with the hydrophobic membrane and recycling system can be used advantageously. Features from one or more of the preferred embodiments of the electrochemical system and/or method that were described earlier can also be applied in the electrochemical system with hydrophobic membrane and recovery system.

In a further presently preferred embodiment of the invention, the method comprises the steps of providing a buffer to the regeneration solution and/or providing a catalyst to the cathode compartment.

Providing a buffer to the regeneration solution is that the buffer prevents limitation of the conductivity of the regeneration solution. As a result the conductivity is increased and an efficient and effective method is achieved. In order to prevent saturation of the resin by the buffer, a buffer with a large particle size is preferred.

Furthermore, providing a catalyst to the cathode compartment results in an increase of the reaction rate of the reaction within the cathode compartment.

Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which: ~ Figure 1 shows a system according to the invention with an electrochemical device; — Figure 2 shows an electrochemical device in an alternative embodiment according to the invention, wherein the electrochemical device comprises an ion exchange resin bed; — Figure 3 shows a further alternative embodiment of the electrochemical device according to the invention, wherein the electrochemical device comprises a bipolar membrane separating the intermediate compartment into at least two intermediate sub- compartments; — Figure 4 shows a schematic overview of the method according to the invention; and — Figure 5 shows experimental results of CO, desorption in the electrochemical device according to the invention, wherein Figure 4 comprises four sub-figures: — SA is cell voltage (V) versus time (h); ~ SB is acidity (pH) versus time (h); — SC is conductivity (mS/cm) versus time {h); and — 5D is CO, flow rate (min/s) versus time (h).

System 2 (Figure 1) comprises electrochemical device 4 and ion exchange resin bed housing 6. In the illustrated embodiment electrochemical device 4 comprises three compartments, anode compartment 8, cathode compartment 12 and intermediate compartment 18.

Anode compartment 8 comprises anode compartment inlet 10 and anode compartment outlet 46. Anode compartment 8 is separated from intermediate compartment 18 with membrane assembly 24. Membrane assembly 24 comprises a membrane and an electrode (not shown and preferably an anode). Assembly 24 enables transfer of protons, or other ions, preferably cations, from anode compartment 8 to intermediate compartment 18.

In a preferred embodiment membrane assembly 24 is a membrane-electrode assembly or a gas diffusion electrode wherein, in use, hydrogen gas can be oxidized and protons are released in compartment 18.

Intermediate compartment 18 comprises intermediate compartment inlet 20 and intermediate compartment outlet 22. Intermediate compartment 18 is separated from cathode compartment 12 with membrane 36. Membrane 36 enables transfer of cations from intermediate compartment 18 to cathode compartment 12.

Cathode compartment 12 comprises cathode compartment inlet 14, cathode outlet 16 and cathode 26. Membrane assembly 24 and cathode 26 connect anode compartment 8 and cathode compartment 12 and enabling transfer of electrons.

In order to generate the hydrogen formation and hydrogen oxidation reaction, in use membrane assembly 24 and cathode 26 are provided with a current via power supply 28.

In the illustrated embodiment an ion exchange resin regeneration solution is provided to intermediate compartment 18 via intermediate compartment inlet 20. Intermediate compartment 18 is configured for regeneration and/or recovery of CO. The obtained solution is removed from intermediate compartment 18 via intermediated compartment outlet 22 and provided to CO: gas- liquid separator 30 via connector 32. CO, gas-liquid separator 30 provides CO; to CO: gas release 44 and regeneration solution to cathode compartment 12 via cathode compartment inlet 14 which is operatively connected with CO» gas-liquid separator 30 via connector 34. Cathode compartment 12 is configured for regeneration of the regeneration solution. The obtained washing solution and dissolved hydrogen is provided to gas-liquid separator 38 via cathode compartment outlet 16. Cathode compartment outlet 16 and gas-liquid separator 38 are operatively connected via connector 40. Gas-liquid separator 38 separates the washing solution and hydrogen, wherein the hydrogen is provided to anode compartment 8 via connector 42. Anode compartment 8 and connector 42 are operatively coupled via anode compartment inlet 10. Connector 42 can comprise additional hydrogen (H,) gas and/or nitrogen (N,) gas input 90.

In the illustrated embodiment of system 2, the washing solution can be provided to ion exchange resin bed housing 6 via connector 96. Connector 96 is operatively coupled with ion exchange resin bed fluid inlet 52 that is configured for providing a fluid to ion exchange resin bed 50, such as a washing solution and/or solvent comprising CO,, such as CO, rich solvent and/or CO: rich washing solution. Ion exchange resin bed 50, comprising beads 48, is able to adsorb and release CO, and/or CO; analogues. Jon exchange resin bed 50 can be charged/loaded via ion exchange resin bed gas inlet 58 that is configured for providing a gas comprising CO», such as CO; rich gas, to the ion exchange resin bed. Furthermore, ion exchange resin bed 50 comprises ion exchange resin bed fluid outlet 56 that is configured for removing a solvent, such as CO: lean solvent and/or regeneration solution, and ion exchange resin bed gas outlet 54, that is configured for removing a gas, such as CO, lean gas. Connector 94 is operatively connected with intermediate compartment inlet 20; to enable the ion exchange resin bed regeneration solution to be provided to intermediate compartment 18 via connector 94, preferably via connector 94 and pump 64.

It will be understood that connector 32, 34, 40, 42, 94 and 96 can be tubing, line, coupling and the like. In a presently preferred embodiment membrane 36 and cathode 26 form a membrane assembly.

System 2 further comprises switching means 60 that are configured for switching between a CO: adsorption state and a regeneration state, and sensor 62 that is configured for measuring the CO: input and/or H; input and/or CO, output and/or H, output and/or CO, purity. In the illustrated embodiment sensor 62 is used for the switching between the states with switching means 60.

In an alternative embodiment electrochemical device 66 (Figure 2) comprises three compartments, anode compartment 8, cathode compartment 12 and intermediate compartment 18. Anode compartment 8 comprises anode 92 and is separated from intermediate compartment 18 with membrane 70, wherein membrane 70 is preferably an AEM. Intermediate compartment 18 comprises ion exchange resin bed 50 and is separated from cathode compartment 12 with membrane 68, wherein membrane 68 is preferably an AEM. Cathode compartment 12 comprises cathode 26, which is operatively coupled with anode 92 via power supply 28. The flow direction through electrochemical device 66 is upstream and shown by arrow 72.

In another alternative embodiment electrochemical device 74 (Figure 3) comprises three compartments, anode compartment 8, cathode compartment 12 and intermediate compartment 18. Anode compartment 8 comprises anode 92 and is separated from intermediate compartment 18 with membrane 70, wherein membrane 70 is preferably an AEM. Intermediate compartment 18 comprises ion exchange resin bed 50 and 51, bipolar membrane 76 and membrane 86, wherein membrane 86 is preferably an AEM. Intermediate compartment 18 is separated from cathode compartment 12 with membrane 68, wherein membrane 68 is preferably an AEM. Bipolar membrane 76 and membrane 86 enable the separation of intermediate compartment 18 into intermediate sub-compartments 78, 80, 82 and 84. In the illustrated embodiment intermediate sub- compartment 80 and 82 comprises ion exchange resin bed 50, compartment 78 comprises a fluid enabling the recovery and/or regeneration 88 of CO,. Cathode compartment 12 comprises cathode 26, which is operatively coupled with anode 92 via power supply 28.

Method 100 {Figure 4) comprises providing an electrochemical device and/or system according to the invention 102. To operate the electrochemical device and/or system, the method comprises electrifying the electrochemical device 104 and providing a regeneration solution to an intermediate compartment 106. Method 100 further comprises forming protons (H") in the anode compartment which can be provided to the intermediate compartment 108, desorbing CO, 110, and separating CO; and regeneration solution 112. Separating CO: and regeneration solution 112 results in recovering CO; as a gas stream 114, wherein the purity of the recovered CO is at least 85%, preferably of at least 90%, and more preferably of at least 95%.

Furthermore, method 100 comprises in-situ regenerating of the regeneration solution 116, wherein regenerating preferably comprises forming the washing solution. Step 116 is followed by separating the regenerated solution and build up hydrogen (H,) gas 118 and in-situ recovering the washing solution 124. The build up hydrogen (H.) gas can be provided to the anode compartment by providing build up hydrogen (H,) gas to the anode compartment 120.

In order to enable the system according to the invention to recover and/or regenerate COs, method 100 comprises providing a gas comprising CO, 122, such as CO, rich gas, to the system according to the invention. Method 100 further comprises removing gas comprising CO,, such as CO, lean gas, from the ion exchange resin bed housing from the system according to the invention

126.

The ion exchange resin bed is treated by the following steps according the method of the invention, flushing the washing solution over the ion exchange resin bed 128, regenerating the ion exchange resin bed 130, and flushing the regeneration solution to the electrochemical device according to the invention 132. Method 100 further comprises providing a fluid through a fluid channel in the intermediate compartment 134, Figure 5 shows experimental results of the electrochemical device according to the invention. In the experiments the anode compartment of the electrochemical device according to the invention was continuously fed with hydrogen gas. The intermediate compartment was fed with an aqueous solution containing 0.15 M NaHCO; and 0.175 M Na,CO; and recirculated at a flow rate of 80 mL/min. The cathode compartment was charged with a 0.5 M NaOH solution, and recirculated at a flow rate of 80 mL/min. The pH and conductivity were measured at the outlet of the intermediate compartment. The amount of CO: produced was measured with a CO; mass flow meter. After an initial transition time, the applied voltage reaches a steady-state value (Figure 5A). In the intermediate compartment, the pH decreases due to the transport of H’ from the anode (Figure 5B). At the same time, the solution conductivity decreases due to transport of Na” towards the cathode (Figure 5C). When the pH drops lower than pH = 6.8, CO; is desorbed from the solution and detected in the CO: gas-liquid separator (Figure 5D). The results show the opportunities of the electrochemical device according to the invention for regeneration and/or recovery of CO, and/or regenerating the regeneration solution to washing liquid.

The present invention is by no means limited to the above described preferred embodiments and/or experiments thereof. The rights sought are defined by the following claims within the scope of which many modifications can be envisaged.

CLAUSES {. Electrochemical device for electrochemically recovery and/or regeneration of carbon dioxide (CO:) from a stream, such as a regeneration solution from an ion exchange resin bed, comprising: - an electrochemical device housing comprising: - an anode compartment, provided with at least one anode compartment inlet that is configured for providing a liquid and/or gas to the anode compartment; — a cathode compartment, provided with at least one cathode compartment inlet that is configured for providing a liquid and/or gas to the cathode compartment, and provided with at least one cathode compartment outlet that is configured for removing a liquid and/or gas from the cathode compartment; and — an intermediate compartment, provided between the anode compartment and the cathode compartment, provided with at least one intermediate compartment inlet that is configured to provide the stream to the intermediate compartment, and at least one intermediate compartment outlet; -— an electrode assembly operatively connecting the anode compartment and the cathode compartment, and comprising at least one anode and one cathode; — a power supply, to provide electricity to the electrode assembly; and -— a CO: gas-liquid separator, wherein the CO: gas-liquid separator is operatively coupled with the intermediate compartment outlet and the cathode compartment inlet.

2. Electrochemical device according to clause 1, wherein the electrode assembly comprises a membrane-electrode assembly and/or a gas-diffusion electrode assembly.

3. Electrochemical device according to clause 2, wherein the intermediate compartment and the anode compartment are separated by the membrane-electrode assembly or the gas-diffusion electrode assembly and/or the intermediate compartment and the cathode compartment are separated by the membrane-clectrode assembly or a gas-diffusion electrode assembly.

4. Electrochemical device according to any one of the preceding clauses, further comprising a gas-liquid separator, wherein the gas-liquid separator is operatively coupled with the cathode compartment outlet and the anode compartment inlet, and wherein the separated gas flows to the anode compartment.

5. Electrochemical device according to any one of the preceding clauses, wherein the CO, gas-liquid separator farther comprises a CO, gas release.

6. Electrochemical device according to any one of the preceding clauses, wherein the CO: is recovered from the CO, gas-liquid separator as a gas stream with a purity of at least 85%, preferably of at least 90%, and more preferably of at least 95%.

7. Electrochemical device according to any one of the preceding clauses, wherein the anode compartment further comprises at least one anode compartment outlet that is configured for removing a liquid and/or gas from the anode compartment.

8. Electrochemical device according to any one of the preceding clauses, wherein the intermediate compartment comprises an ion exchange resin bed.

9. Electrochemical device according to clause 8, wherein the ion exchange resin bed is an anion exchange resin bed and/or size exclusion ion exchange resin bed.

10. Electrochemical device according to any one of the preceding clauses, further comprising at least one bipolar membrane, configured for separating the intermediate compartment into at least two intermediate sub-compartments.

11. Electrochemical device according to clause 10, wherein the ion exchange resin bed is provided in at least one of the at least two intermediate sub-compartments, and wherein a liquid compartment is provided in at least an other one of the at least two intermediate sub-compartments.

12. Electrochemical device according to any one of the preceding clauses, further comprising an additional hydrogen (H;) gas and/or nitrogen (N,) gas input, wherein the gas input is configured for providing hydrogen (H;) gas and/or nitrogen (N;) gas to the anode compartment.

13. Electrochemical device according to any one of the preceding clauses, wherein the stream comprises a buffer.

14. Electrochemical device according to clause 13, wherein the buffer is one or more selected from the group of aqueous sodium chloride, aqueous potassium chloride, aqueous potassium phosphate, aqueous sodium phosphate, aqueous sodium acetate, aqueous acetic acid, aqueous boric acid, aqueous citric acid, aqueous phosphoric acid.

15. Electrochemical device according to any one of the preceding clauses, wherein the cathode compartment further comprises a catalyst, wherein the catalyst is one or more selected from the group of electrochemical catalysts, chemical catalyst, and microbial catalyst.

16. System for electrochemically recovery and/or regeneration of carbon dioxide (CO) from a stream, such as a regeneration solution from an ion exchange resin bed, comprising: ~ an electrochemical device according to any one of the preceding clauses; and — an ion exchange resin bed housing, comprising: — an ion exchange resin bed; — at least one ion exchange resin bed fluid inlet that is configured for providing a fluid to the ion exchange resin bed, such as a washing solution and/or solvent comprising CO; — at least one ion exchange resin bed gas inlet that is configured for providing a gas comprising CO», such as CO: rich gas, to the ion exchange resin bed; — at least one ion exchange resin bed fluid outlet that is configured for removing a solvent, such as CO, lean solvent and/or regeneration solution, from the ion exchange resin bed; and — at least one ion exchange resin bed gas outlet that is configured for removing a gas, such as CO; lean gas, from the ion exchange resin bed.

17. System according to clause 16, wherein the ion exchange resin bed comprises an anion exchange resin bed and/or size exclusion ion exchange resin bed.

18. System according to clause 16 or 17, further comprising switching means that are configured for switching between a CO, adsorption state and a regeneration state.

19. System according to any one of the clauses 16 — 18, further comprising at least one sensor that is configured for measuring the CO, input and/or H: input and/or CO, output and/or H, output and/or CO; purity.

20. Method for clectrochemically recovery and/or regeneration of carbon dioxide (CO) from a stream, such as a regeneration solution from an ion exchange resin bed, comprising the steps of: ~ providing an electrochemical device according to any one of the clauses | - 15 and/or system according to any one of the clauses 16 — 19; ~ electrifying the electrochemical device; — providing an regeneration solution to an intermediate compartment; — forming protons (H") in the anode compartment which can be provided to the intermediate compartment; — desorbing CO:; — separating CO, and regeneration solution; ~ in-situ regenerating of the regeneration solution, preferably forming the washing solution; — separating the regenerated solution and build up hydrogen (H;) gas; and ~ in-situ recovering the washing solution.

21. Method according to clause 20, wherein CO: is recovered as gas stream with a purity of at least 85%, preferably of at least 90%, and more preferably of at least 95%.

22. Method according to clause 20 or 21, wherein the regeneration solution comprises a wet regeneration solution comprising adsorbed COs.

23. Method according to any one of the clauses 20, 21 or 22, further comprising the step of providing a gas comprising CO,, such as CO; rich gas, to the system according to any one of the clauses 16 — 19.

24, Method according to clause 23, wherein the gas comprising CO, is a wet gas comprising CO».

25. Method according to any one of the clauses 20 — 24, further comprising the step of removing gas comprising CO,, such as CO; lean gas, from the ion exchange resin bed housing from the system according to any one of the clauses 16 ~ 19.

26. Method according to any one of the clauses 20 — 25, further comprising the steps of: ~ flushing the washing solution over the ion exchange resin bed; — regenerating the ion exchange resin bed; and — flushing the regeneration solution to the electrochemical device according to any one of the clauses 1 — 15.

27. Method according to any one of the clauses 20 — 26, further comprising the step of providing a fluid through a fluid channel in the intermediate compartment,

28. Method according to any one of the clauses 20 — 27, further comprising the step of providing a buffer to the regeneration solution.

29. Method according to any one of the clauses 20 — 28, further comprising the step of providing a catalyst to the cathode compartment.

Claims

CONCLUSIONS i. Electrochemical device for electrochemical recovery and/or regeneration of carbon dioxide (CO) from a stream, such as an ion exchange resin bed regeneration solution, comprising: - an electrochemical device housing comprising: - an anode compartment provided with at least one anode compartment inlet adapted to providing a liquid and/or gas to the anode compartment; - a cathode compartment provided with at least one cathode compartment inlet adapted to supply a liquid and/or gas to the cathode compartment, and provided with at least one cathode compartment outlet adapted to remove a liquid and/or gas from the cathode compartment; and - an intermediate compartment provided between the anode compartment and the cathode compartment, provided with at least one intermediate compartment inlet arranged to supply power to the intermediate compartment, and at least one intermediate compartment outlet; -- an electrode assembly operatively connecting the anode compartment and the cathode compartment, comprising at least one anode and one cathode; - a power supply for supplying electricity to the electrode assembly; and - a CO:gas-liquid separator, wherein the CO:gas-liquid separator is operably connected to the intermediate compartment outlet and the cathode compartment inlet.

The electrochemical device of claim 1, wherein the electrode assembly comprises a membrane electrode assembly and/or a gas diffusion electrode assembly.

The electrochemical device of claim 2, wherein the intermediate compartment and the anode compartment are separated by the membrane electrode assembly or the gas diffusion electrode assembly and/or the intermediate compartment and the cathode compartment are separated by the membrane electrode assembly or the gas diffusion electrode assembly.

An electrochemical device according to any preceding claim, further comprising a gas-liquid separator, wherein the gas-liquid separator is operatively connected to the cathode compartment outlet and the anode compartment inlet, and wherein the separated gas flows to the anode compartment.

An electrochemical device according to any one of the preceding claims, wherein the CO 2 gas-liquid separator further comprises a CO 2 gas outlet.

An electrochemical device according to any one of the preceding claims, wherein the CO 1 is recovered from a CO; gas-liquid separator as a gas stream with a purity of at least 85%. preferably at least 90%, and more preferably at least 95%.

An electrochemical device according to any one of the preceding claims, wherein the anode compartment further comprises at least one anode compartment outlet adapted to remove a liquid and/or gas from the anode compartment.

An electrochemical device according to any one of the preceding claims, wherein the intermediate compartment comprises an ion exchange resin bed.

The electrochemical device of claim 8, wherein the ion exchange resin bed is an anion exchange resin bed and/or high exclusion ion exchange resin bed.

An electrochemical device according to any one of the preceding claims, further comprising at least one bipolar membrane adapted to separate the intermediate compartment into at least two intermediate sub-compartments.

The electrochemical device of claim 10, wherein the ion exchange resin bed is provided in at least one of the at least intermediate sub-compartments, and wherein a liquid is provided in at least one other of the two intermediate sub-compartments.

An electrochemical device according to any one of the preceding claims, further comprising an additional hydrogen (H 2 ) gas and/or nitrogen (N 2 ) gas inlet, wherein the gas inlet is arranged to supply hydrogen (H 2 ) gas and/or nitrogen (N 2 ) to the anode compartment.

An electrochemical device according to any preceding claim, wherein the current comprises a buffer.

The electrochemical device of claim 13, wherein the buffer is one or more selected from the group of aqueous sodium chloride, aqueous potassium chloride, aqueous potassium phosphate, aqueous sodium phosphate, aqueous sodium acetate, aqueous acetic acid, aqueous boric acid, aqueous citric acid, aqueous phosphoric acid.

The electrochemical device of any preceding claim, wherein the cathode compartment further comprises a catalyst, the catalyst being one or more selected from the group of electrochemical catalyst, chemical catalyst, and microbial catalyst.

A system for electrochemically recovering and/or regenerating carbon dioxide (CO 2 ) from a stream, such as an ion exchange resin bed regeneration solution, comprising: an electrochemical device according to any one of the preceding claims, and an ion exchange resin bed housing, comprising: — an ion exchange resin bed; ~ at least one ion exchange resin bed fluid inlet configured to supply a fluid to the ion exchange resin bed, such as a wash solution and/or a CO containing solvent; — at least one ion exchange resin bed gas inlet arranged to supply a gas comprising CO), such as CO:rich gas, to the ion exchange resin bed; — at least one ion exchange resin bed fluid outlet configured to remove a solvent, such as CO 2 depleted solvent and/or regenerating solution, from the ion exchange resin bed; and — at least one ion-exchange resin bed gas outlet configured to remove a gas, such as CO2 lean gas, from the ion-exchange resin bed.

The system of claim 16, wherein the ion exchange resin bed comprises an anion exchange resin bed and/or high exclusion ion exchange resin bed.

A system according to claim 16 or 17, further comprising switching means adapted to switch between a CO, adsorption state and a regeneration state.

A system according to any one of claims 16 - 18, further comprising at least one sensor adapted to measure the CO, input and/or H, input and/or CO, output and/or H, output and/or CO : purity.

A method for electrochemically recovering and/or regenerating carbon dioxide {CO2) from a stream, such as an ion exchange resin bed regeneration solution, comprising the steps of: - providing an electrochemical device according to any one of claims 1 to 15 and/ or system according to any one of claims 16-19; ~ electrifying the electrochemical device; - providing a regeneration solution to an intermediate compartment; — the formation of protons (H*) in the anode compartment that can be provided to the intermediate compartment; — desorbing CO:; — separating CO, and regeneration solution; ~ regenerating the regenerating solution in-situ, preferably forming the wash solution; — separating the regenerated solution and built-up hydrogen (H 2 ) gas; and — recovering the wash solution in-situ.

A process according to claim 20, wherein CO 1 is recovered as a gas stream with a purity of at least 85%, preferably at least 90%, and more preferably at least 95%.

The method of claim 20 or 21, wherein the regeneration solution comprises a wet regeneration solution comprising absorbed CO: .

A method according to any one of claims 20, 21 or 22, further comprising the step of providing a gas comprising CO, such as CO 2 -rich gas, to the system according to any one of claims 16-19.

The method of claim 23, wherein the gas comprising CO is a wet gas comprising CO.

The method of any one of claims 20 to 24, further comprising the step of removing gas comprising CO, such as CO2 lean gas, from the ion exchange resin bed housing of the system as claimed in any one of claims 16 to 19.

A method according to any one of claims 20 to 25, further comprising the steps of: - flowing the wash solution over the ion exchange resin bed; — regenerating the ion exchange resin bed; and & o> ~ flowing the regenerating solution to the electrochemical device according to any one of claims 1 to 15.

A method according to any one of claims 20 to 26, further comprising the step of providing a flow through a flow channel in the intermediate compartment,

A method according to any one of claims 20 to 27, further comprising the step of providing a buffer to the regeneration solution.

A method according to any one of claims 20 to 28, further comprising the step of providing a catalyst to the cathode compartment.