Method for solvent regeneration used in carbon capture and / or sulphur capture, membrane device, membrane stack, and system to perform said method

Abstract

The invention relates to a method for solvent regeneration used in carbon capture and / or sulphur capture, a membrane device, a membrane stack, and a system to perform said method. The method comprises the steps of: - providing a membrane device, comprising: - two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode; and - at least one membrane between the two or more compartments; - providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent comprises a dissolved carbon-based gas and / or a dissolved sulphur-based gas; - feeding hydrogen gas to the compartment comprising the anode; - applying an electrical potential difference between the anode and the cathode; - degassing the aqueous solvent stream; and - releasing the carbon-based gas and / or the sulphur-based gas from the membrane device.

Description

[0001] METHOD FOR SOLVENT REGENERATION USED IN CARBON CAPTURE AND / OR

[0002] SULPHUR CAPTURE, MEMBRANE DEVICE, MEMBRANE STACK, AND SYSTEM TO

[0003] PERFORM SAID METHOD

[0004] The present invention relates to a method for solvent regeneration used in carbon capture and / or sulphur capture, a membrane device, a membrane stack, and a system to perform said method.

[0005] Conventional methods and / or systems for solvent regeneration used in carbon capture and / or sulphur capture use alkaline solutions as absorbent. The regeneration of said alkaline absorbent includes temperature swings. Conventionally, the alkaline, for example NaOH, is regenerated by exchanging sodium and calcium ions by dosing calcium hydroxide. Subsequently, the resulting calcite (CaCOs) precipitate is thermally treated at 700 °C to produce CO2 and calcium oxide. Finally, calcium hydroxide can be regenerated by rehydration of calcium oxide. Therefore, the subsequent regeneration of the alkaline solution is highly energy-demanding.

[0006] These problems prevent an efficient and effective solvent regeneration used in carbon capture and / or sulphur capture, as the conventional methods and systems require a large amount of energy. This problem is even bigger for large scale regeneration of solvents used in carbon capture and / or sulphur capture. Thus, conventional methods and systems are not suitable for high throughput.

[0007] An objective of the present invention is to provide a method for solvent regeneration used in carbon capture and / or sulphur capture that obviates or at least reduces one or more of the aforementioned problems and / or is more effective as compared to conventional methods and systems.

[0008] This objective is achieved with the method for solvent regeneration used in carbon capture and / or sulphur capture, comprising the steps of: providing a membrane device, comprising: two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode; and at least one membrane between the two or more compartments; providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent stream comprises a dissolved carbon-based gas and / or a dissolved sulphur-based gas; feeding hydrogen gas to the compartment comprising the anode; applying an electrical potential difference between the anode and the cathode; degassing the aqueous solvent stream; and releasing the carbon-based gas and / or the sulphur-based gas from the membrane device.

[0009] It is noted that carbon capture relates to capturing carbon, for example carbon in a gaseous waste stream. Furthermore, the carbon capture relates to capturing carbon moieties. Said carbon moieties may also be referred to as molecules comprising carbon, wherein said molecules are preferably in a gas state at ambient conditions.

[0010] It is also noted that sulphur capture relates to capturing sulphur, for example sulphur in a gaseous waste stream. Furthermore, the sulphur capture relates to capturing sulphur moieties. Said sulphur moieties may also be referred to as molecules comprising sulphur, wherein said molecules are preferably in a gas state at ambient conditions.

[0011] It is also noted that releasing in this application relates to removing the carbon-based gas and / or the sulphur based-gas from the membrane device. In other words, the carbon-based gas and / or the sulphur based-gas may be captured, for example in the aqueous solvent stream, followed by setting said gas free.

[0012] It is also noted that, throughout this application unless otherwise stated, an aqueous solvent stream refers to a solvent stream comprising water.

[0013] It is also noted that throughout this application an electrical potential difference may include providing an electric current.

[0014] The method according to the invention may start with the step of providing a membrane device. Said membrane device comprises two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode. Furthermore, at least one membrane is assembled between the two or more compartments.

[0015] It is noted that, throughout this application, the compartment comprising the cathode may also be referred to as cathode compartment comprising a cathode. Furthermore, the compartment comprising the anode may also be referred to as anode compartment comprising an anode.

[0016] The two or more compartments extend at least partially between the anode and the cathode, wherein the two or more compartments are separated by the at least one membrane. Thus, the at least one membrane is configured to define two or more compartments.

[0017] The step of providing may than be followed by the step of providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent stream comprises a dissolved carbon-based gas and / or a dissolved sulphur-based gas, and followed by the steps of feeding hydrogen gas to the compartment and applying an electrical potential difference between the anode and the cathode. The step of applying an electrical potential difference may be followed by the steps of degassing the aqueous solvent stream, and releasing the carbon-based gas and / or the sulphur-based gas from the membrane device. It is noted that throughout this application an aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas may refer to an enriched aqueous solvent stream, wherein the aqueous solvent stream is enriched with a carbon-based gas and / or sulphurbased gas.

[0018] In a preferred embodiment, the aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas is solely provided to the compartment comprising the cathode.

[0019] In a further preferred embodiment, the carbon-based gas and / or sulphur-based gas is dissolved in the aqueous solvent stream outside the membrane device. For example, waste carbonbased gas and / or waste sulphur-based gas may be dissolved in the aqueous solvent stream.

[0020] Without being bound to theory, the aqueous solvent may absorb the carbon-based gas and / or the sulphur-based gas, wherein bicarbonate and / or carbonate, and / or bisulphide and / or sulphide respectively are formed. Alternatively, or in addition to, the aqueous solvent may act as nucleophile that bind to the electrophilic carbon centre of the carbon-based gas and / or the electrophilic sulphur centre of the sulphur-based gas.

[0021] Degassing / desorption and thus releasing may occur by introducing excessive protons, such that bicarbonate (HCO3 ) and / or carbonate (CO32), and / or bisulphide (HS ) and / or sulphide (S2) react with said protons. Alternatively, or in addition to, a H+ / 0H pair and / or a redox couple can be applied to regenerate the aqueous solvent stream.

[0022] Capturing a carbon-based gas and / or a sulphur-based gas may be a multi-step process, comprising absorption and desorption. Furthermore, capturing a carbon-based gas and / or a sulphur-based gas may also include dissolving said gasses in the aqueous solvent. The method according to the invention enables to selectively capture the carbon-based gas and / or the sulphurbased gas from other gasses. In particular, the method according to the invention enables selective adsorption and desorption. This enables a pure carbon-based gas and / or sulphur-based gas release from the aqueous solvent.

[0023] The potential difference comprises an overall voltage, which comprises four parts: equilibrium potential, activation overpotential, ohmic resistance, and mass transport overpotential.

[0024] The equilibrium potential Eeqis defined by the reactant concentration and the product concentration. Said equilibrium potential is provided by the Gibbs standard energy of the reaction, for example the hydrogen oxidation process and hydrogen evolution reaction. Furthermore, the additional potential supplied to the membrane device is the overpotential. It is noted that in the low current density region (< 10 A nr2), the applied potential difference is mainly attributed by the activation overpotential (activation energy) of the electrodes. Therefore, the relation between the potential difference and the current density may be defined by the Butler-Volmer equation (see Equation 1).

[0025] Equation 1

[0026] In Equation 1 j is the electrode current density (A m2). jo is the exchange current density (A m2), rf is the activation overpotential (V), F is the Faraday constant, R is the universal gas constant, T is the absolute temperature (K), aais the anodic charge transfer coefficient, and acis the cathodic charge transfer coefficient.

[0027] For higher current density, the potential difference is mainly attributed by the ohmic resistance, it has a linear relationship with the current density supplied to the electrodes. The ohmic resistance is comprised from ion resistance, membrane resistance and overall contact resistance of the setup (see Equation 2).

[0028] Equation 2

[0029] In Equation 2 and in equation 3 Rxis the ohmic resistance of each compartment and i is the current.

[0030] Furthermore, high current density relates to mass transport overpotentials need to be considered. This term becomes significant when reaction kinetic became the limit of the process. In the desired current density operated with this invention, mass transport overpotential is not a limiting factor, thus we only consider the ohmic overpotential and activation overpotential at this stage (see Equation 3).

[0031] Veen = Eeq+ a + b - log(t) + ^ Rx ■ i Equation 3

[0032] In Equation 3 Vceii is the cell voltage, Eeqis the equilibrium potential for the redox reaction, and a + b • log(z) is the activation energy required as described in the Tafel equation.

[0033] An advantage of the method according to the invention is that an aqueous solvent comprising a carbon-based gas and / or a sulphur-based gas may be efficiently and effectively recovered, wherein the carbon-based gas and / or sulphur-based is released or stripped from said aqueous solvent. Furthermore, a carbon-based gas and / or sulphur-based gas may be obtained with a high purity. It was found that the method according to the invention provides an efficient (aqueous) solvent regeneration using a current of about 2 mA cm2, wherein an energy consumption of 60 kJ mol1CO2 could be reached. Conventional systems include an energy consumption of about 150 kJ mol Thus, the method according to the invention is more efficient and effective compared to conventional methods for solvent regeneration used in carbon capture and / or sulphur capture.

[0034] A further advantage of the method according to the invention is that said method enables a pH-swing. As a result, the energy consumption for solvent regeneration used in carbon capture and / or sulphur capture may be reduced compared to conventional methods.

[0035] For example, the method according to the invention may be performed using aqueous methyl diethanolamine (CHsWCLlLOHb). The amine group may react with CO2 to produce bicarbonate ions.

[0036] It is noted that a pH-swing may refer to a method used in CO2 capture technologies, specifically in processes involving the absorption and desorption of CO2 from a flue gas stream. A pH-swing is employed in processes such as amine-based absorption.

[0037] In amine-based absorption, a liquid solvent, typically an amine solution, is used to absorb CO2 from the flue gas, forming a rich solvent. The absorption occurs at a relatively high pH, typically above 9. The rich solvent, containing the absorbed CO2, is then subjected to a desorption process to release the captured CO2 for further use or storage. During desorption, the pH of the solvent is lowered, often below 7, to promote the release of CO2.

[0038] The pH-swing technique involves adjusting the pH of the solvent between high and low values during the absorption and desorption stages. By raising the pH during absorption, the CO2 absorption efficiency is enhanced, allowing for greater capture of CO2 from the flue gas. Lowering the pH during desorption helps to facilitate the release of CO2 from the solvent, enabling its subsequent capture or utilization.

[0039] In addition, in an electrochemical process, a pH-swing refers to the pH difference established across the ion exchange membrane (anion exchange membrane in our invention), the pH-swing also affect the energy consumption of an electrochemical solvent regeneration process. The bigger the pH-swing, the higher the required voltage, which is described by 0.0592-ApH (as stated in eq.7) resulting in an increase energy demand for the process. With a buffer (such as MDEA, DEA, MEA) as the solvent, the advantage is that both compartments will stay in the mild pH zones and thus a smaller pH gap is achieved.

[0040] The pH-swing management in carbon capture aims to optimize the overall efficiency of the process by manipulating the pH of the solvent at different stages. It helps to improve CO2 absorption rates during absorption and reduce energy requirements during desorption, leading to a more effective carbon capture system. It is noted that in Equation 4 for CPENlCTIROHb Ri represents CH3 and R2 and R3 represents C2H4OH.

[0041] Equation 4

[0042] Feeding hydrogen gas to the compartment comprising the anode accelerates the proton formation. Therefore, the equilibrium in Equation 4 lays on the left side. In other words, the equilibrium lays in the formation of carbon dioxide (CO2) and / or hydrogen sulphide (H2S).

[0043] Furthermore, the mechanism explained in Equation 4 may include that the aqueous methyl diethanolamine may be provided to the compartment comprising the cathode. In said aqueous stream HCO3 ions will be formed and transported through the membrane, for example an anion exchange membrane (AEM), to the compartment comprising the anode. Said transport of the bicarbonate may be due to the electric potential applied between the anode and the cathode. In addition to, or alternatively, said transport of the bicarbonate may be due to the concentration gradient across the at least one membrane. At the anode, hydrogen may be oxidized on the membrane electrode assembly to form protons. Protons may further bind with the HCO3 ions transported from the compartment comprising the cathode and form H2CO3, said reaction is explained in Equation 5.

[0044] H2CO3 CO2+ H2O

[0045] Equation 5

[0046] Furthermore, at the cathode water may be reduced to form hydrogen and hydroxyl. The protonated amine may react with the hydroxyl ion and regain alkalinity (see Equation 6). Equation 6

[0047] Alternatively, protons may be transported through the membrane, for example a proton exchange membrane, to the compartment comprising the anode. Said protons may than react with HCO ; ions instead of forming CO2 directly in a compartment closest to the anode and delineated by the at least one membrane and / or membrane electrode assembly.

[0048] In a preferred embodiment, the anode and / or cathode comprises one or more element selected from the group of platinum, titanium, nickel, gold. For example, the anode and / or cathode may be a platinum-coated titanium electrode.

[0049] In a presently preferred embodiment according to the invention, the method according to the invention further comprises the step of providing a membrane electrode assembly comprising the compartment comprising the anode and one of the at least one membrane.

[0050] An advantage of a membrane electrode assembly is that the carbon-based gas and / or the sulphur-based gas is released from said membrane assembly. As a result, the carbon-based gas and / or the sulphur-based gas can be efficiently and effectively collected. Furthermore, said membrane assembly enables that the carbon-based gas and / or the sulphur-based gas is at least 80% pure, preferably at least 90% pure, more preferably at least 92% pure, even more preferably at least 95% pure, wherein the purity of said gas stream is defined as a gas stream wherein at least 80% of the volume, preferably at least 90% of the volume, more preferably at least 92% of the volume, even more preferably at least 95% of the volume, is a gas comprising carbon and / or sulphur.

[0051] The membrane electrode assembly according to the invention may comprise a gas diffusion layer, a catalyst layer, and a membrane. Preferably, the gas diffusion layer is a separated from the catalyst layer. The gas diffusion layer enables to optimize / maximize the hydrogen contact with the catalyst. Preferably, the gas diffusion layer comprises carbon and / or titanium. After the gas diffuses through the gas diffusion layer, the gas is contacted with a catalyst layer, preferably comprising platinum and / or nickel. Ions may be transported from the catalyst layer via a membrane away from the catalyst layer.

[0052] In a further presently preferred embodiment according to the invention, the membrane electrode assembly comprises a catalyst.

[0053] An advantage of the catalyst present in the membrane electrode assembly is that the energy demands for the solvent regeneration used in carbon capture and / or sulphur capture are reduced. Therefore, a more energy efficient and effective method is achieved.

[0054] In a preferred embodiment, the catalyst comprises one or more selected from the group of ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, rhenium, gold, titanium, nickel, iron. Preferably, the catalyst comprises nickel and / or platinum.

[0055] In a preferred embodiment, the catalyst is a layer, such as a platinum carbon-based gas diffusion layer, wherein said layer is assembled in the membrane electrode assembly.

[0056] An advantage of a membrane electrode assembly comprising a catalyst is that the solvent regeneration is increased. As a result, the method according to the invention may be used to process large volumes and becomes more cost effective. In a further presently preferred embodiment according to the invention, the membrane electrode assembly may be an anion exchange membrane electrode assembly. In addition to, or alternatively, the membrane electrode assembly may be a proton exchange membrane electrode assembly.

[0057] It was found that an anion exchange membrane electrode assembly and / or proton exchange membrane electrode assembly enables an efficient and effective method for solvent regeneration used in carbon capture and / or sulphur capture.

[0058] In a further presently preferred embodiment according to the invention, the step of degassing comprises the step of regenerating the aqueous solvent stream.

[0059] It was found that degassing the aqueous solvent stream enables to regenerate the aqueous solvent stream. As a result, a circular aqueous solvent used in carbon capture and / or sulphur capture is achieved.

[0060] In a further presently preferred embodiment according to the invention, the method according to the invention further comprises the step of providing the membrane device with at least two membranes between the compartment comprising the cathode and the compartment comprising the anode, wherein a second membrane partly delineates the compartment comprising the cathode, and providing at least three or more compartments.

[0061] The at least two membranes provide one or more intermediate compartments, wherein said compartments are delineated by the two or more membranes.

[0062] An advantage of at least three or more compartments is that the step of releasing the carbonbased gas and / or the sulphur-based gas from the membrane device is more efficient as the carbonbased gas and / or the sulphur-based gas may be released from the compartment not comprising an electrode. As a result, the throughput of the aqueous stream enriched with the carbon-based gas and / or the sulphur-based gas is increased as the equilibrium of releasing the carbon-based gas and / or the sulphur-based gas does not lay in a compartment with an electrode.

[0063] In a further presently preferred embodiment according to the invention, the method according to the invention further comprises the step of conducting a pH-swing in the another of the two or more compartments comprises an anode and / or conducting a pH-swing in the compartment delineated by the at least two membranes, wherein the pH-swing may be between pH 0 and pH 14, preferably pH 2 and pH 10, more preferably pH 3 and pH 9, even more preferably pH 4 and pH 8.

[0064] It is noted that a pH-swing includes a swing, also referred to as oscillation, of the pH in a compartment, wherein the pH in a compartment goes from low to high and vice versa. In other words, the pH in the compartment delineated by the at least two membranes may swing / oscillate between pH 2 and pH 10 and back to pH 2. The minimum potential to establish a pH-swing may be determined by the pH difference between the anode and the cathode. It was found that the minimal potential drop per pH unit was 59.2 mV per pH unit to achieve an efficient and effective method according to the invention. The potential drop could be determined by Equation 7.

[0065] / R • T\ VpH= 2.303 • ( -^ ) • pH = 0.0592 • Ap / 7 Equation 7

[0066] It is noted that R refers to the gas constant, T refers to the temperature in Kelvin, and F refers to the Faraday constant.

[0067] The pH-swing of the method according to the invention enables an efficient and effective carbon capture and / or sulphur capture. For example, the pH-swing enables a method according to the invention used in carbon dioxide (CO2) capture technologies, such as methods involving the absorption and desorption of CO2 from a flue gas stream. The pH-swing is employed in processes such as amine-based absorption.

[0068] In amine-based absorption, a liquid solvent, for example an amine solution, is provided to absorb CO2 from the flue gas, forming a rich solvent (carbon gas enriched solvent). The absorption may occur at a relatively high pH, for example a pH of 9 or higher. The rich solvent, comprising the absorbed CO2, may be subjected to a desorption process (such as degassing the aqueous solvent stream) to release the captured CO2 for further use or storage. During desorption, the pH of the solvent is lowered, for example to a pH of 7 or lower, to promote the release of CO2.

[0069] The pH-swing technique includes adjusting the pH of the solvent between high and low values during the absorption and desorption (degassing) stages. By raising the pH during absorption, the CO2 absorption efficiency is enhanced, allowing for greater capture of CO2 from the flue gas. Towering the pH during desorption helps to facilitate the release of CO2 from the solvent, enabling its subsequent capture or utilization.

[0070] It is noted that the pH-swing refers to the pH difference established across the ion exchange membrane (such as an anion exchange membrane).

[0071] Without being bound to theory, the pH-swing also affect the energy consumption of a (electrochemical) solvent regeneration. The bigger the pH-swing, the higher the required voltage, which is described by 0.0592 • ApH (see equation 7) resulting in an increase energy demand for the method according to the invention. Using a buffer, preferably an aqueous buffer, (like MDEA, DEA, MEA) as the solvent, both compartments may stay between the mild pH zones and thus a smaller pH gap.

[0072] It is noted that that the abovementioned example may also be applicable for other gasses. An advantage of a pH-swing is that in the compartment delineated by the at least two membranes is that the solution in the compartment delineated by the at least two membranes is that the amount of energy used to apply a potential difference between the anode and the cathode is reduced compared to a conventional method for solvent regeneration used in carbon capture and / or sulphur capture.

[0073] In a further presently preferred embodiment according to the invention, the second membrane may be an anion exchange membrane.

[0074] It was found that the second membrane being an anion exchange membrane enables an efficient and effective method according to the invention. In fact, an efficient and effective anion transport is achieved, for example an efficient (bi)carbonate transport is achieved.

[0075] In a further presently preferred embodiment according to the invention, the method according to the invention further comprises the step of providing the compartment delineated by the at least two membranes with conductive media.

[0076] The conductive media enables an efficient and effective for solvent regeneration used in carbon capture and / or sulphur capture. Furthermore, an advantage of the conductive media is that a pH-swing in the compartment comprising the conductive media is efficiently achieved.

[0077] For example, conductive media may be provided to a compartment delineated by at least two membranes, wherein said compartment(s) may also be referred to as intermediate compartment(s).

[0078] In a further presently preferred embodiment according to the invention, the conductive media may be one a conductive resin and / or and ionic liquid, preferably the conductive resin is an anion exchange resin.

[0079] It was found that an anion exchange resin increased the regeneration of the solvent used in carbon capture and / or sulphur capture compared to a method without said anion exchange resin.

[0080] In a further presently preferred embodiment according to the invention, the aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas comprises 0.001 mol L1to 10 mol L1carbon-based gas and / or sulphur-based gas, preferably 0.1 mol L1to 5 mol L ', more preferably 0.5 mol L1to 4 mol L ', even more preferably 0.5 mol L1to 2 mol L ', most preferably 1 mol L1to 1.5 mol L '.

[0081] In a further presently preferred embodiment according to the invention, the carbon-based gas may be substantially carbon dioxide and / or the sulphur-based gas may be substantially hydrogen sulphide.

[0082] It is noted that small concentrations of other carbon-based gasses and / or sulphur-based gasses may be dissolved in the aqueous solvent stream.

[0083] In a preferred embodiment, the step of providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas, comprises the step of providing an aqueous solvent stream comprising dissolved carbon dioxide to the compartment comprising the cathode.

[0084] In a further presently preferred embodiment according to the invention, the aqueous solvent stream comprises an amine. Preferably, the amine comprises one or more selected from the group of monoethanolamine, diglycolamine, diethanolamine, diisopropanolamine, triethanolamine, methyldiethanolamine, methyl diethanolamine, piperazine, aminomethyl propanol, aminoethylethanolamine, 2-(diethylamino)-ethanol, / V, / V-dimcthylcthanolaminc, triethylene diamine, diisopropanolamine.

[0085] It was found that the aqueous solvent stream comprising one or more of the abovementioned amines provides an efficient and effective method for solvent regeneration used in carbon capture and / or sulphur capture.

[0086] Yet another advantage of the method according to the invention is that the method according to the invention requires less energy compared to conventional solvent regeneration used in carbon capture and / or sulphur capture.

[0087] In a further presently preferred embodiment according to the invention, the amine may be present in a concentration in the range of 0.25 mol L1to 4 mol L ', preferably in the range of 0.25 mol L1to 3 mol L ', more preferably in the range of 0.25 mol L1to 2 mol L ', even more preferably in the range of 0.5 mol L1to 2 mol L '.

[0088] It was found that the abovementioned amine concentrations were sufficient to achieve a low energy demand.

[0089] In a further presently preferred embodiment according to the invention, the aqueous solvent stream comprises one or more selected from the group of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium hydroxide, lithium carbonate, lithium bicarbonate, ammonium.

[0090] An advantage of one or more selected from the group of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium bicarbonate, lithium hydroxide, lithium carbonate, ammonium is that bicarbonate or carbonate, or bisulphide or sulphide ions are more efficiently formed in the membrane device and / or aqueous solvent stream.

[0091] In a further presently preferred embodiment according to the invention, the aqueous solvent stream comprises one or more selected from the group of calcium carbonate, magnesium carbonate, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, forming an aqueous suspension.

[0092] In a further presently preferred embodiment according to the invention, the method further comprises the step of providing at least one bipolar membrane to the membrane device.

[0093] An advantage of at least one bipolar membrane is that a membrane stack may be achieved. As a result, the capacity if the membrane device is increased and the rate of regeneration of the aqueous solvent stream is increased. Therefore, the aqueous solvent may efficiently and effectively regenerated and used to capture carbon-based gas and / or capture sulphur-based gas.

[0094] In a further presently preferred embodiment according to the invention, the method according to the invention further comprises the step of capturing a carbon-based gas and / or a sulphur-based gas in the aqueous solvent stream.

[0095] The invention also relates to a membrane device for solvent regeneration used in carbon capture and / or sulphur capture, comprising: two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode; at least one membrane between the two or more compartments; an aqueous solvent stream inlet which is operatively coupled with the compartment comprising the cathode, and is configured to provide an aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas; an aqueous solvent stream outlet which is operatively coupled with the compartment comprising the cathode, and is configured to remove an aqueous solvent stream; a gas inlet which is operatively couped with the compartment comprising the anode; and means for applying an electrical potential difference between the anode and the cathode, wherein the compartment comprising the cathode is configured to, during use, be provided with an aqueous solvent stream, wherein the aqueous solvent stream comprises a dissolved carbonbased gas and / or a dissolved sulphur-based gas.

[0096] The membrane device for solvent regeneration used in carbon capture and / or sulphur capture according to the invention provides the same effects and advantages as those described for the method for solvent regeneration used in carbon capture and / or sulphur capture.

[0097] Preferably, the membrane device is configured to perform the method according to the invention.

[0098] In a presently preferred embodiment according to the invention, one of the at least one membrane is a membrane electrode assembly, preferably an anion exchange membrane electrode assembly and / or proton exchange membrane electrode assembly.

[0099] In a further presently preferred embodiment according to the invention, the at least one membrane are at least two membranes, assembled between the compartment comprising the cathode and the compartment comprising the anode. Preferably, the second membrane is an anion exchange membrane.

[0100] In a further presently preferred embodiment according to the invention, the membrane device further comprises at least one bipolar membrane. The invention also relates to a membrane stack for solvent regeneration used in carbon capture and / or sulphur capture, the stack comprises a number of cells which are configured to perform the method according to the invention.

[0101] The membrane stack for solvent regeneration used in carbon capture and / or sulphur capture according to the invention provides the same effects and advantages as those described for the method for solvent regeneration used in carbon capture and / or sulphur capture according to the invention, and the membrane device for solvent regeneration used in carbon capture and / or sulphur capture according to the invention.

[0102] The invention also relates to a system for solvent regeneration used in carbon capture and / or sulphur capture, comprising: a membrane device according to the invention; an aqueous solvent comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas supply that is operatively coupled to the compartment comprising the cathode; and an outlet that is configured to discharge a carbon-based gas and / or a sulphur-based gas from the device.

[0103] The system for solvent regeneration used in carbon capture and / or sulphur capture according to the invention provides the same effects and advantages as those described for the method for solvent regeneration used in carbon capture and / or sulphur capture according to the invention, the membrane device for solvent regeneration used in carbon capture and / or sulphur capture according to the invention, and the membrane stack for solvent regeneration used in carbon capture and / or sulphur capture according to the invention.

[0104] In a preferred embodiment, the system according to the invention further comprises an outlet that is configured to discharge a carbon-based gas and / or a sulphur-based gas stripped aqueous solvent from the device.

[0105] In a presently preferred embodiment according to the invention, the system further comprises a capturing device, wherein the capturing device is configured to capture a carbon-based gas and / or a sulphur-based gas, and is operatively coupled with membrane device.

[0106] It is noted that capturing a carbon-based gas and / or a sulphur-based gas includes dissolving a carbon-based gas and / or a sulphur-based gas in an aqueous solvent.

[0107] Said capturing device may be operatively coupled with a gas outlet of a factory, house, or office building.

[0108] An advantage is that the (environmental) hazardous carbon-based gasses and / or sulphurbased gasses may be trapped on side. Therefore, emissions of said gasses is reduced and less pollution is emitted in the open air. 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:

[0109] - Figure 1A shows a schematic overview of the method according to the invention;

[0110] - Figure IB shows a schematic overview of the method for solvent regeneration;

[0111] - Figure 2 shows a schematic overview of the membrane device according to the invention comprising an anion exchange membrane electrode assembly;

[0112] - Figure 3 shows a schematic overview of the membrane device according to the invention comprising a proton exchange membrane electrode assembly;

[0113] - Figure 4 shows a schematic overview of the membrane stack according to the invention;

[0114] - Figure 5 shows a voltage versus current (UI) response and energy consumption (EC) response for the method according to the invention, using the membrane device according to the invention;

[0115] - Figure 6 shows the energy consumption for the method according to the invention using different configurations of the membrane device according to the invention;

[0116] - Figure 7 shows a UI response for the method according to the invention using a membrane device comprising a proton exchange membrane electrode assembly and a methyl diethanolamine buffered aqueous solvent stream;

[0117] - Figure 8 shows the percentage of the CO2 in a production stream in downstream processes for different CO2 to H2 ratios;

[0118] - Figure 9 shows the system performance with ten absorption-desorption cycles at 50 A / m2;

[0119] - Figure 10 shows the contact angle measurement before (A) and after (B) 10 cyclic operations;

[0120] - Figure 11 shows the MDEA concentration during ten cyclic operations for reference and experimental groups;

[0121] - Figure 12 shows the polarization curves of two cell designs: triangles (AEMEA), dots (PEMEA), upper curve represents anode potential, lower curve represents cathode potential;

[0122] - Figure 13 shows a cathode with a coating of ion exchange resin; and

[0123] - Figure 14 shows a voltage response and carbon dioxide content under different current densities.

[0124] Method 10 (Figure 1A) for solvent regeneration used in carbon capture and / or sulphur capture follows a sequence of steps.

[0125] In the illustrated embodiment method 10 may start with the step 12 of providing a membrane device. Step 12 may be followed by step 14 of providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent stream comprises a dissolved a carbon-based gas and / or a dissolved sulphur-based gas.

[0126] In a preferred embodiment, step 12 may be followed by step 13 of providing a membrane electrode assembly comprising the compartment comprising the anode and one of the at least one membrane and / or step 15 of providing the membrane device with at least two membranes between the compartment comprising the cathode and the compartment comprising the anode, wherein a second membrane partly delineates the compartment comprising the cathode, and providing at least three or more compartments. Preferably, step 15 may comprise step 19 of providing the compartment delineated by the at least two membranes with conductive media

[0127] In a further preferred embodiment, step 12 may be followed by step 21 of providing at least one bipolar membrane to the membrane device.

[0128] Step 14 may be followed by step 16 of applying an electrical potential difference between the anode and the cathode.

[0129] In a preferred embodiment, step 14 may be followed by step 20 of feeding hydrogen gas to the compartment comprising the anode. Furthermore, before step 14 step 22 of capturing a carbonbased gas and / or a sulphur-based gas in the aqueous solvent stream may be performed.

[0130] In the preferred embodiment that method 10 comprises step 15, step 16 may be followed by step 17 of conducting a pH-swing in the compartment delineated by the at least two membranes, wherein the pH-swing is between pH 2 and pH 10, preferably pH 3 and pH 9, more preferably pH 4 and pH 8.

[0131] Furthermore, step 16 and / or step 17 may be followed by step 18 of degassing the aqueous solvent stream and step 24 of releasing the carbon-based gas and / or the sulphur-based gas from the membrane device.

[0132] Method 1 (Figure IB) for solvent regeneration used in carbon capture and / or sulphur capture follows a sequence of steps.

[0133] In the illustrated embodiment method 1 may start with step 2 of providing a carbon-based gas and / or a sulphur-based gas to a capturing device. Step 2 may be followed by step 3 of capturing the carbon-based gas and / or sulphur-based gas in an aqueous solvent. It is noted that capturing may include dissolving the carbon-based gas and / or sulphur-based gas in the aqueous solvent.

[0134] Furthermore, method 1 may comprise step 4 of providing the aqueous solvent comprising dissolved carbon-based gas and / or sulphur-based gas to the system according to the invention. Step 4 may be followed by step 5 of stripping the dissolved carbon-based gas and / or the dissolved sulphur-based from the aqueous solvent. The aqueous solvent may than be recycled in step 6 of recycling the aqueous solvent to the capturing device. Step 5 mat be followed by step 7 of releasing the carbon-based gas and / or sulphur-based gas. Membrane device 30 (Figure 2) comprises compartments 32 and 34, an anode 36, and a cathode 38. Said compartments are separated by membrane 40. Preferably, membrane 40 is membrane electrode assembly 42, more preferably membrane electrode assembly 42 is an anion exchange membrane electrode assembly.

[0135] Compartment 34 is provided with aqueous solvent stream 44. Preferably, aqueous solvent stream 44 is an enriched carbon-based gas and / or a sulphur-based gas aqueous solvent stream. More preferably, said aqueous solvent stream comprises an amine.

[0136] Anode 36 and cathode 38 are operatively coupled via means 46 which are configured to apply an electrical potential.

[0137] Furthermore, membrane device 30 comprises aqueous solvent stream 48 which is lean in carbon-based gas and / or a sulphur-based. Said electrical potential enables to release a gas from membrane device 30 via gas release 50.

[0138] Membrane device 52 (Figure 3) comprises compartments 32, 34, and 58, an anode 36, and a cathode 38. Furthermore, membrane device 52 further comprises membranes 56 and 62, wherein membrane 56 partly delineates compartments 34 and 58, membrane 62 partly delineates compartments 32 and 58. Thus, compartments 32 and 58 are separated by membrane 62, and compartments 34 and 58 are separated by membrane 56.

[0139] Membrane 62 is preferably a membrane electrode assembly, more preferably a proton exchange membrane electrode assembly. Furthermore, membrane 56 is preferably an anion exchange membrane.

[0140] Compartment 34 is provided with aqueous solvent stream 44. Preferably, aqueous solvent stream 44 is an enriched carbon-based gas and / or a sulphur-based gas aqueous solvent stream. More preferably, said aqueous solvent stream comprises an amine. Compartment 58 may be provided with conductive media 64.

[0141] Anode 36 and cathode 38 are operatively coupled via means 46 which are configured to apply an electrical potential.

[0142] Furthermore, membrane device 52 comprises aqueous solvent stream 48 which is lean in carbon-based gas and / or a sulphur-based. Said electrical potential enables to release a gas from membrane device 52 via gas release 60.

[0143] Membrane stack 70 (Figure 4) comprises anode 72 and cathode 74, wherein anode 72 and cathode 74 are operatively coupled via means 76 configured for applying a potential difference between anode 72 and cathode 74.

[0144] Furthermore, membrane stack 70 comprises membranes 78 and 80, delineating one or more of compartments 82, 84, 86, 88, and 90. In addition, compartments 86 and 90 are provided via inlet 92 with an aqueous solvent stream which is enriched with a carbon-based gas and / or sulphur-based gas. Preferably, said aqueous solvent stream comprises an amine. An aqueous solvent stream lean in carbon-based gas and / or sulphur-based gas may be withdrawn from membrane stack 70 via outlet 96. Carbon-based gas and / or sulphur-based gas may be removed from compartments 84 and 88 from membrane stack 70 via outlet 98.

[0145] In a preferred embodiment, hydrogen gas is provided to electrode 72 via hydrogen inlet 94.

[0146] In an experiment, anion exchange membrane electrode assembly was configured with an anion exchange membrane, for example a Fujifilm anion exchange membrane type I / II, and / or Fumasep FAA, FAB, and FAS series, and a gas diffusion layer, for example carbon layer or titanium layer, with a catalyst, for example platinum and / or nickel. (E.g. carbon-FAA-3 anion exchange membrane electrode assembly preparation: Vulcan® XC72 gas diffusion layer, provided with a platinum catalyst ink, and further integrated with the FAA-3 Fumasep membrane. The ink was prepared by dissolving Fumion (ionomer of FAA) in ethanol, mixed with Pt / C particles, and PTFE. The anion exchange membrane electrode assembly can be assembled either with hot pressing, solvent welding or physical compression). For the CCF-loadcd aqueous solvent regenerated such as ethanolamine (ME A), diethanolamine (DEA), methyl diethanolamine (MDEA), potassium (bi)carbonate, and other alkaline solvents.

[0147] CCE-loaded / enriched aqueous solvent comprising MDEA was regenerated using a membrane device comprising a proton exchange membrane electrode assembly at room temperature, and under a current density of 100 A m2. The energy consumption of the membrane device was measured, being 115 kJ mol1and resulted in a >95% pure CO2 stream.

[0148] CCE-loaded / enriched aqueous solvent comprising MDEA was regenerated using a membrane device comprising a proton exchange membrane electrode assembly and a (saturated) anion exchange resin in the middle compartment (the compartment delineated by at least two membranes) at room temperature, and under a current density of 20 A m2. The energy consumption of the membrane device was measured, being 63 kJ mol1at a current density of 20 A m2and resulted in a >95% pure CO2 stream (Figure 5). It is noted that the left bar of each triplet of bars refers to MDEA, the middle bar of each triplet of bars refers to DEA, and the left bar of each triplet of bars refers to MEA. In addition, the bottom line at a current density of 80 A m2refers to MDEA, the middle line at a current density of 80 A m2refers to DEA, and the top line at a current density of 80 A m2refers to MEA.

[0149] In a further experiment, it was found that, a current efficiency during experiments with CCE- loaded / enriched aqueous solvent stream comprising MDEA is almost 100%, regardless of the (commercially available) used membranes.

[0150] In an even further experiment (see Figure 6), the energy consumption of a conventional method using a membrane device comprising a cation exchange membrane and an aqueous solvent comprising potassium hydroxide (top line at a current density of 100 A m2) was tested alongside the method according to the invention comprising an anion exchange membrane electrode assembly and an aqueous solvent comprising MDEA (middle line at a current density of 100 A m2) and a proton exchange membrane electrode assembly and an aqueous solvent comprising MDEA (bottom line at a current density of 100 A m2).

[0151] It was found that under 100 A m2, the method according to the invention provides at least 15% reduction in energy consumption for the method according to the invention using an anion exchange membrane electrode assembly, and provides at least a 55% reduction in energy consumption for the method according to the invention using a proton exchange membrane electrode assembly.

[0152] In a further experiment, the method according to the invention comprises a membrane device comprising a proton exchange membrane electrode assembly. The method according to the invention provided to the compartment comprising the anode a solution of 0.4 mol L1formic acid and 0.05 mol L1sulfuric acid. The compartment comprising the cathode was provided with 0.5 mol L1MDEA. The UI response is shown in Figure 7. It was found that the method according to the invention using a membrane device comprising a proton exchange membrane electrode assembly retains a significant designability in the electrolyte applied.

[0153] In a further experiment it was found that introducing MDEA buffer to the aqueous solvent stream and / or as electrolyte on the anode side, a high proton concentration (low pH) on the anode was prevented. As a result, (cheaper) catalysts, such as nickel based catalysts (which are usually unstable in an acidic condition), can be used in the method according to the invention. Furthermore, it was found that providing a buffer, for example a MDEA buffer, on both sides of the one or more membranes is that the pH difference on both sides of the one or more membranes may be adjusted, such that excessive pH swings are avoided.

[0154] Said experiments showed an efficient and effective regeneration of the solvent used in carbon capture and / or sulphur capture.

[0155] In a further experiment (figure 8) the flexibility and reliability for further integration for carbon conversion was tested. In the experiment a membrane device according to figure 2 was used. Said membrane device has an additional advantages, being that the output of the produced gas stream is tuneable. By adjusting the hydrogen input, it was found that precise control of the production gas composition can be achieved. In the experiments, a current density of 50 A / m2was maintained. By varying the H2 input rates (33 mL / min, 28 mL / min, 18 mL / min, and 11 mL / min), each for one hour and the CO2 percentage in the production stream is recorded by an infrared sensor, are supplied to produce different hydrogen-to-carbon dioxide ratios of 1:4, 1:3, 1:2 and 1:1 for downstream carbon conversion. In addition, in a further experiment the hydrogen input was kept at 20mL / min, each for one hour and the CO2 percentage in the production stream is recorded by an infrared sensor, and current densities of 32 A / m2, 41 A / m2, 57 A / m2, 96 A / m2were supplied to produce different hydrogen-to-carbon dioxide ratios (1:1, 1:2, 1:3, 1:4) for potential downstream carbon conversion. This tunability allows for the direct use of the product gas in various downstream processing applications. Table 1 summarizes the potential downstream processes for different CO2:H2 ratios.

[0156] Table 1: Downstream processes for different CO2:H2 ratios.

[0157] In a further experiment, the reliability of the carbon capture procedures according to the invention was explored by applying 10 cycles of absorption and desorption using a membrane device according to figure 2. In each cycle, 70% of the carbon loading capacity was regenerated, and CO2 was replenished to saturate the solution for the next cycle. The MDEA solution was not renewed between experiments. At the end of the experiment, the MDEA solution was sampled and analyzed by ion chromatography to assess any potential degradation. Additionally, a reference group with MDEA solution under ambient air (1 atm, 298K) was set up to identify any degradation unrelated to the electrochemical process. Contact angle measurements were conducted before and after the experiments to assess potential wetting on the membrane electrode assembly.

[0158] The 10 cycles of absorption-desorption experiments demonstrated a notably high repeatability in performance (figure 9), underscoring the robustness of the process. For example, it was found that the process showed high stability across multiple cycles, with consistent regeneration and replenishment of CO2, the average energy consumption was measured at 74.2 kJ / mol at 50 A / m2, indicating an efficient process, the pH levels remained within the optimal range of 8 to 9.5 throughout the experiments, the CO2 percentage in the production stream ranged from 15% to 25%, demonstrating reliable performance. In addition, ion chromatography analysis indicated minimal degradation of the MDEA solution over multiple cycles, and contact angle measurements (figure 10, table 2) showed that the membrane electrode assembly maintained its performance without significant wetting issues.

[0159] Table 2: Contact angle measurements.

[0160] The stability tests confirmed the reliability and efficiency of the carbon capture process. The experiments highlighted the robustness and repeatability of the electrochemical pH swing process. The consistent performance across multiple cycles, efficient energy consumption, and minimal degradation of the MDEA solution underscore the potential of this process for practical applications (figure 11).

[0161] In a further experiment, it was shown that an electrochemical pH swing can regulate the absorption-desorption of CO2 in the solvent. By utilizing the hydrogen oxidation / evolution reaction (HER / HOR) as a symmetric redox reaction, the method facilitated the establishment of two distinct pH zones: low pH for CO2 depletion and high pH for solvent regeneration. The minimum energy consumption in this approach is determined by the pH swing created, which can reach up to 14 in a pH swing established by unbuffered HER / HOR. By utilizing amine as the carbon capture solution, which also acts as a chemical buffer at the cathode, the local pH at the cathode can be decreased during regeneration process with the HER.

[0162] With the AEMEA design as mentioned in figure 2, it was found that the anodic potential can be reduced with a buffer. In addition, the design according to figure 2 (AEMEA design) was compared with the design according to figure 3 (PEMEA design). In the PEMEA design, proton production occurs on the catalyst layer (i.e. Pt catalyst), resulting in a local pH as low as 0 - 1. Conversely, in the AEM-based MEA utilizing Fumion as the ionomer, bicarbonate can be transported to the catalyst layer and act as a chemical buffer.

[0163] Equation 8

[0164] The bicarbonate buffer will effectively regulate the pH to a milder state (pH 5-6). Introducing the carbonic acid (H2CO3) reaction (eq 8) in the catalyst increases the local pH (from pH 0-1 (HER) to pH 5-6 (buffered HER)), subsequently lowering the anodic potential of the hydrogen oxidation reaction. This is also visible in figure 12, the anodic potential shifted downward.

[0165] In a further experiment, are a class of room temperature molten salts composed of an anion and a cation. Compared to other liquids, ionic liquids offer several specific advantages, such as excellent chemical stability and a wide electrochemical window. Most importantly, ionic liquids can be tailored by modification of functional groups, enabling the design of functional and environmentally friendly ionic liquids.

[0166] The ionic liquids of interest for the study are amino-based cations (for example but not limited to l-ethyl-3-methylimidazolium [EMIM], l-butyl-3-methyl-imidazolium [BMIM]) and typical anions (for example but not limited to hydroxide [OH], methanesulfonate [MeSOs]). These ionic liquids can also be used in aqueous solution at various concentrations (up to 10%).

[0167] The amino-based ionic liquids mentioned above use their amine groups to capture CO2. Amino-based ionic liquids exhibit conductivities similar to other amines and alkaline solvents tested in the electrochemical system, typically in the range of 10 mS / cm to 50 mS / cm, resulting in comparable low ohmic resistance and UI curves. Certain ionic liquids also promise advantages in terms of lowering the activation energy for water splitting. It was found that a reduction in activation energy of 10 kJ / mol for the hydrogen evolution reaction when using [EMIM JfMeSOs], resulting in a reduction in energy consumption for carbon capture of approximately 0.22 GJ / ton.

[0168] An intriguing development is the usage of multi-amino functionalized ionic liquids. These ionic liquids can increase carbon loading due to the presence of multiple amino groups, enhancing the efficiency of CO2 capture. Additionally, when the ionic liquid is only partially regenerated, it remains positively charged. This positive charge can potentially inhibit undesired diffusion processes, further improving the performance of the ionic liquids in CO2 capture applications.

[0169] In summary, amino-based ionic liquids, particularly those with dual-amino functionality, hold significant potential for efficient CO2 capture. Their ability to be tailored through functional group modifications, combined with their advantageous electrochemical properties, enables them for reducing energy consumption and improving the overall efficiency of CO2 capture systems.

[0170] In a further experiment, the feasibility of using ion exchange resin (“AMBERLITE™” HPR4800 OH Ion Exchange Resin, an anion exchange resin) as a solid solvent in the cathodic chamber was investigated. Instead of supplying a liquid solvent, the ion exchange resin is coated and pressed onto the cathode as shown in figure 13.

[0171] To ensure that the resin is saturated with CO2, the cathodic compartment is supplied with CO2 overnight prior to the experiment. During the experiment, an infrared CO2 sensor is placed at the outlet of the anode to measure the percentage of CO2. Hydrogen is supplied to the anode at a rate of 20 mL / min. Different current densities (10, 20, 30 and 40 A / m2) are applied, with each step lasting 30 minutes. CO2 is continuously fed to the cathode to maintain resin saturation. The gas mixture, consisting of the CO2 produced and the excess H2, was analysed using an infrared CO2 sensor (SmartGAS Flow EVO, Germany).

[0172] As shown in figure 14, the production of CO2 is reflected in the increased CO2 content in the mixed stream (H2 / CO2 mixture). The percentage of CO2 in the outlet stream increases with increasing current densities. In the control group (no current applied, 0 A / m2) the CO2 percentage remains low (~ 2%). However, a significant increase in CO2 is observed with increasing current density. Voltage increases with increasing current due to ohmic resistance. In particular, higher current densities lead to fluctuations throughout the experiment, indicating more significant gas formation at the electrodes (H2 in the cathode and CO2 in the anode).

[0173] These results confirm the viability of using ion exchange resin as a solid solvent for the invented CO2 capture device and demonstrate a clear correlation between current density and CO2 production.

[0174] 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.

Claims

CLAIMS1. Method for solvent regeneration used in carbon capture and / or sulphur capture, comprising the steps of: providing a membrane device, comprising: two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode; and at least one membrane between the two or more compartments; providing an aqueous solvent stream to the compartment comprising the cathode, wherein the aqueous solvent stream comprises a dissolved carbon-based gas and / or a dissolved sulphur-based gas; feeding hydrogen gas to the compartment comprising the anode; applying an electrical potential difference between the anode and the cathode; degassing the aqueous solvent stream; and releasing the carbon-based gas and / or the sulphur-based gas from the membrane device.

2. Method according to claim 1 , further comprising the step of providing a membrane electrode assembly comprising the compartment comprising the anode and one of the at least one membrane.

3. Method according to claim 2, wherein the membrane electrode assembly comprises a catalyst, preferably wherein the catalyst comprises nickel and / or platinum.

4. Method according to claim 2 or 3, wherein the membrane electrode assembly is an anion exchange membrane electrode assembly.

5. Method according to claim 2, 3, or 4, wherein the membrane electrode assembly is a proton exchange membrane electrode assembly.

6. Method according to any one of the preceding claims, wherein the step of degassing comprises the step of regenerating the aqueous solvent stream.

7. Method according to any one of the preceding claims, further comprising the step of providing the membrane device with at least two membranes between the compartment comprisingthe cathode and the compartment comprising the anode, wherein a second membrane partly delineates the compartment comprising the cathode, and providing at least three or more compartments.

8. Method according to any one of the preceding claims, further comprising the step of conducting a pH-swing in the another of the two or more compartments comprising an anode, and / or when dependent on claim 7 conducting a pH-swing in the compartment delineated by the at least two membranes, wherein the pH-swing is between pH 0 and pH 14, preferably pH 2 and pH 10, more preferably pH 3 and pH 9, even more preferably pH 4 and pH 8.

9. Method according to claim 7 or 8, wherein the second membrane is an anion exchange membrane.

10. Method according to claim 7, 8, or 9, further comprising the step of providing the compartment delineated by the at least two membranes with conductive media.

11. Method according to claim 10, wherein the conductive media is a conductive resin and / or an ionic liquid, preferably the conductive resin is an anion exchange resin.

12. Method according to any one of the preceding claims, wherein the aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas comprises 0.001 mol L1to 10 mol L1carbon-based gas and / or sulphur-based gas, preferably 0.1 mol L1to 5 mol L ', more preferably 0.5 mol L1to 4 mol L ', even more preferably 0.5 mol L1to 2 mol L ', most preferably 1 mol L1to 1.5 mol L '.

13. Method according to any one of the preceding claims, wherein the carbon-based gas is substantially carbon dioxide and / or the sulphur-based gas is substantially hydrogen sulphide.

14. Method according to any one of the preceding claims, wherein the aqueous solvent stream comprises an amine.

15. Method according to claim 14, wherein the amine comprises one or more selected from the group of monoethanolamine, diglycolamine, diethanolamine, diisopropanolamine, triethanolamine, methyldiethanolamine, methyl diethanolamine, piperazine, aminomethyl propanol, aminoethylethanolamine, 2-(diethylamino)-ethanol, / V, / V-dimcthylcthanolaminc, triethylene diamine, diisopropanolamine.

16. Method according to claim 14 or 15, wherein the amine is present in a concentration in the range of 0.25 mol L1to 4 mol L ', preferably in the range of 0.25 mol L1to 3 mol L ', more preferably in the range of 0.25 mol L1to 2 mol L ', even more preferably in the range of 0.5 mol L1to 2 mol L '.

17. Method according to any one of the preceding claims, wherein the aqueous solvent stream comprises one or more selected from the group of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium hydroxide, lithium carbonate, lithium bicarbonate, ammonium.

18. Method according to any one of the preceding claims, wherein the aqueous solvent stream comprises one or more selected from the group of calcium carbonate, magnesium carbonate, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, forming an aqueous suspension.

19. Method according to any one of the preceding claims, further comprising the step of providing at least one bipolar membrane to the membrane device.

20. Method according to any one of the preceding claims, further comprising the step of capturing a carbon-based gas and / or a sulphur-based gas in the aqueous solvent stream.

21. Membrane device for solvent regeneration used in carbon capture and / or sulphur capture, comprising: two or more compartments, wherein one of the two or more compartments comprises a cathode and wherein another of the two or more compartments comprises an anode; at least one membrane between the two or more compartments; an aqueous solvent stream inlet which is operatively coupled with the compartment comprising the cathode, and is configured to provide an aqueous solvent stream comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas; an aqueous solvent stream outlet which is operatively coupled with the compartment comprising the cathode, and is configured to remove an aqueous solvent stream; a gas inlet which is operatively couped with the compartment comprising the anode; and means for applying an electrical potential difference between the anode and the cathode,wherein the compartment comprising the cathode is configured to, during use, be provided with an aqueous solvent stream, wherein the aqueous solvent stream comprises a dissolved carbonbased gas and / or a dissolved sulphur-based gas.

22. Membrane device according to claim 21, wherein one of the at least one membrane is a membrane electrode assembly, preferably an anion exchange membrane electrode assembly and / or proton exchange membrane electrode assembly.

23. Membrane device according to claim 21 or 22, wherein the at least one membrane are at least two membranes, assembled between the compartment comprising the cathode and the compartment comprising the anode.

24. Membrane device according to claim 23, wherein the second membrane is an anion exchange membrane.

25. Membrane device according to any one of the claims 21 to 24, further comprising at least one bipolar membrane.

26. System for solvent regeneration used in carbon capture and / or sulphur capture, comprising: a membrane device according to any one of the claims 21 to 25; an aqueous solvent comprising a dissolved carbon-based gas and / or a dissolved sulphur-based gas supply that is operatively coupled to the compartment comprising the cathode; and an outlet that is configured to discharge a carbon-based gas and / or a sulphur-based gas from the membrane device.

27. System according to claim 26, further comprising a capturing device, wherein the capturing device is configured to capture a carbon-based gas and / or a sulphur-based gas, and is operatively coupled with membrane device.

28. Use of the system according to claim 26 or 27 for solvent regeneration used in carbon capture and / or sulphur capture.

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