Direct capture of carbon dioxide from air

Abstract

The present invention relates to an apparatus and method for capturing CO2 directly from air. The apparatus comprises: (a) an at least partially air-permeable membrane comprising a solid CO2 adsorbent; (b) at least one adsorption chamber; (c) at least one regeneration chamber; (d) means for transferring the membrane from the adsorption chamber to the regeneration chamber and back; (e) an inlet for receiving air at one end of the membrane and an outlet for discharging CO2-depleted air at the other end of the membrane in the adsorption chamber, wherein the apparatus is configured to allow air to flow from the inlet through the membrane to the outlet; (f) means for allowing stripping gas to flow through the membrane into the regeneration chamber; (g) at least one outlet in the regeneration chamber for discharging CO2; and (h) heating means for heating the regeneration chamber. The apparatus according to the present invention provides an efficient and low-cost solution for capturing CO2 directly from air.

Description

Technical Field

[0001] The present invention is in the field of carbon dioxide capture, in particular capturing carbon dioxide directly from air. The present invention relates to an apparatus and a method for capturing carbon dioxide from air. Background Art

[0002] Recently, the desire to reduce the human carbon dioxide footprint has led to the development of many methods or processes in which CO2 (the main greenhouse gas causing global warming) is used as a raw material for useful products. Ironically, these emerging technologies are hindered by the limited availability of CO2. Methods for capturing CO2 from CO2-rich gases (such as industrial flue gases) have been developed, but cannot meet the demand for CO2. In addition, such methods can reduce CO2 emissions into the environment, and the concentration of CO2 already present in the environment is not affected. Therefore, it is necessary to capture CO2 directly from the air, which will reduce the CO2 concentration in the environment and provide a further renewable CO2 source.

[0003] Currently known devices and methods for capturing CO2 from air have very low efficiencies, as the low CO2 concentrations in the air are highly detrimental to the economic viability of such methods. An overview of existing methods is provided in Direct air capture of CO2 with chemicals - A technology assessment for the AP Spanel on public affairs, June 1, 2011, APS Physics (https: / / www.aps.org / policy / reports / assessments / upload / dac2011.pdf) and Sanz-Pérez et al., Chem. Rev. 2016, 116, 11840-11876.

[0004] Carbon Engineering has developed a system in which the CO2 adsorbent is dissolved in an aqueous membrane. Air passes through the membrane (thickness 50 μm) and is then passed to a regeneration unit where CO2 is desorbed from the adsorbent in solution. The membrane ensures that only a small pressure difference is required to achieve contact between the air and the CO2 adsorbent. However, a big disadvantage of this system is the energy-intensive regeneration of the dissolved adsorbent. High temperatures are required, which leads to high operating costs.

[0005] Fluidized bed reactors are also known, see, for example, Zhang et al., Chemical Engineering Science, 2014, 116, pp. 306-316. Air is purged through a bed containing porous particles, in which the pores have been coated with a CO2 adsorbent. Since air will be more easily transferred between particles than through the interior of the particles, the effective contact time between the air and the adsorbent will be much lower than the actual residence time of the air in the bed. In order to ensure sufficient contact time between the air and the CO2 adsorbent, a bed height of about 7 meters is typically required, which means that efforts are needed to force the air through this large column, i.e., a high pressure difference is required to allow the air to pass through the column, which is energy intensive.

[0006] Also known is the Veloxotherm system, which is not used to capture CO2 from air but from flue gases, which have an increased CO2 content. This system comprises a rotating disc (thickness 40 cm) with a solid CO2 content. At one point, CO2-rich gas flows through the disc, where CO2 is adsorbed and CO2-lean gas is discharged to the environment. The loaded adsorbent rotates away to a different point, where stripping gas (steam) flows through the disc. A mixture of CO2 and steam is obtained.

[0007] FR2826877 relates to a device for adsorbing molecules transported in ambient air, comprising a hollow cylindrical drum rotating about its axis and having a circumferential wall made of two concentric perforated metal plates (22, 23) enclosing a layer of adsorbent material (24). The device can be used to dehumidify or purify air. The adsorbent material can include silica, activated carbon or zeolite.

[0008] WO2015 / 103401 describes a system for removing carbon dioxide from a gas mixture, the system comprising two groups of carbon dioxide removal structures, each removal structure within each group comprising a porous solid substrate supported on the structure, each porous substrate having an adsorbent supported on its surface, the adsorbent being capable of adsorbing or binding to carbon dioxide to remove carbon dioxide from the gas mixture.

[0009] WO2015 / 006259 describes a method for separating CO2 from a gas stream, the method comprising passing the gas stream through an adsorbent that adsorbs CO2 and recovering the CO2 by concentration swing adsorption and adsorption displacement. The method does not rely on temperature swing adsorption. The adsorbent may include an alkalized substrate.

[0010] The present invention addresses the need for an efficient and economically viable device for capturing CO2 directly from air, which avoids the large pressure differential of a fluidized bed reactor and the energy-consuming regeneration of a loaded sorbent dissolved in water. The advantages of the low pressure differential of a membrane are combined with the advantages of a solid sorbent requiring reduced energy for regeneration. Thus, the present invention provides an energy-efficient solution for capturing CO2 directly from air. Summary of the invention

[0011] The inventors have developed an apparatus and method for capturing CO2 directly from air. The invention can be defined according to the following list of preferred embodiments:

[0012] 1. Use of a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent, for capturing CO2 from air.

[0013] 2. The use according to embodiment 1, wherein the membrane comprises a stack of thin films comprising pores having a diameter in the range of 50 μm-500 μm in diameter, and each thin film is covered with a macroporous material comprising the adsorbent.

[0014] 3. The use according to embodiment 1 or 2, wherein the use involves air flow through the membrane, the air flow preferably passing through the membrane perpendicularly to the membrane.

[0015] 4. A device for capturing CO2 from air, comprising:

[0016] (a) an at least partially air-permeable membrane, said membrane consisting of a macroporous layer, wherein the pores of said macroporous layer are coated with a solid CO2 adsorbent;

[0017] (b) at least one adsorption chamber;

[0018] (c) at least one regeneration chamber;

[0019] (d) means for transferring the membrane from the adsorption chamber to the regeneration chamber and back;

[0020] (e) an inlet located on one side of the membrane for receiving air, and an outlet located on the other side of the membrane in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow through the membrane from the inlet to the outlet;

[0021] (f) means for flowing a stripping gas through the membrane into the regeneration chamber;

[0022] (g) at least one outlet in the regeneration chamber for exhausting CO2; and

[0023] (h) A heating device for heating the regeneration chamber.

[0024] 5. The device of use according to embodiment 4, wherein the membrane comprises a stack of thin films comprising pores having a diameter in the range of 50 μm-500 μm in diameter, and each thin film is covered with a macroporous material comprising the adsorbent.

[0025] 6. The device according to embodiment 4 or 5, wherein the membrane has the form of a ring, preferably a cylinder or a conveyor belt.

[0026] 7. The apparatus of any one of embodiments 4-6, wherein the apparatus further comprises:

[0027] (a) a cylinder including the membrane, the membrane being in the shape of a circumferential wall centered around a vertical central axis;

[0028] wherein the device (d) is used to rotate the cylinder around the vertical axis, and wherein one or more of the adsorption chambers are delimited by a portion of the circumferential wall and a partition wall; and wherein one or more of the regeneration chambers are delimited by another portion of the circumferential wall and a partition wall.

[0029] 8. The apparatus of any one of embodiments 4-6, wherein the apparatus further comprises:

[0030] (a) a tape body comprising the film as a separate layer;

[0031] wherein the device (d) is used to transport the belt through one or more of the adsorption chambers and one or more of the regeneration chambers; and wherein one or more of the adsorption chambers are delimited by a portion of the membrane and a partition wall, and wherein one or more of the regeneration chambers are delimited by another portion of the membrane and a partition wall.

[0032] 9. The device according to any one of embodiments 4-8, wherein the membrane consists of a microporous backing layer and a macroporous top layer, wherein the pores of the macroporous top layer are coated with a solid CO2 adsorbent.

[0033] 10. The device according to any one of Examples 4-9 further includes a CO2 recycling device (j), wherein the CO2 recycling device (j) is configured to allow the stripping gas to flow through the membrane into the regeneration chamber (c), wherein the recycling device includes a device for separating a product CO2 stream from a recycling stream, wherein the product CO2 stream can be discharged through the outlet (g) for discharging CO2, and the recycling stream is returned to the regeneration chamber (c).

[0034] 11. An apparatus according to any one of embodiments 4-10, wherein the heating device (h) is capable of heating the solid CO2 adsorbent to a temperature in the range of 50°C-100°C, preferably to a temperature in the range of 60°C-85°C, and most preferably to a temperature in the range of 67°C-75°C when positioned adjacent to or within the regeneration chamber.

[0035] 12. The apparatus of any one of embodiments 4-11, wherein the heating device is capable of heating a stripping gas that flows through the membrane into the regeneration chamber.

[0036] 13. The device according to any one of embodiments 4-12, comprising 1-20 adsorption chambers and 1-20 regeneration chambers.

[0037] 14. The device according to any one of embodiments 4-13, wherein the CO2 adsorbent is selected from the group consisting of bicarbonate-based adsorbents, amine-based adsorbents and metal-organic frameworks.

[0038] 15. The device of any one of embodiments 4-14, wherein the junction between the adsorption chamber and the regeneration chamber is gas-tight.

[0039] 16. The apparatus according to any one of embodiments 4-15, wherein the heating device (h) is capable of heating the regeneration chamber to a temperature higher than a temperature of the adsorption chamber.

[0040] 17. A method for capturing CO2 from air, comprising:

[0041] (i) moving a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent, from an adsorption section to a regeneration section;

[0042] (ii) providing an air flow through the membrane at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent;

[0043] (iii) providing a stripping gas stream through the membrane at the regeneration section at an elevated temperature to obtain a product stream comprising CO2 and a regenerated solid CO2 adsorbent;

[0044] Wherein, adsorption of CO2 by the solid CO2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO2 adsorbent.

[0045] 18. The method of embodiment 17, wherein the moving of step (i) involves rotating a cylinder having a circumferential wall about a central vertical axis, wherein the circumferential wall comprises the membrane.

[0046] 19. The method of embodiment 17, wherein the moving of step (i) involves conveying a belt through the adsorption chamber and the regeneration chamber, wherein the belt includes the membrane.

[0047] 20. A method according to any one of embodiments 17-19, wherein the stripping gas is provided by recycling from the product stream, wherein the product stream comprising CO2 obtained in (ii) is separated into a product CO2 stream and a recycle stream comprising the stripping gas, and the recycle stream is recycled to (ii).

[0048] 21. The method of any one of embodiments 17-20, further comprising:

[0049] (iv) during (ii), heating the stripping gas to the elevated temperature before the stripping gas passes through the film.

[0050] 22. The method of any one of embodiments 17-21, wherein the method is performed using the apparatus of any one of embodiments 4-15.

[0051] 23. Use of a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid adsorbent, for capturing gaseous substances from air, wherein the adsorbent is selected for the gaseous substances.

[0052] 24. The use according to embodiment 23, wherein the gaseous substance is selected from carbon oxides, sulfur oxides and nitrogen oxides, preferably SO x and / or NO x .

[0053] 25. The use according to embodiment 23 or 24, wherein the membrane is incorporated into a device according to any one of embodiments 4-16.

[0054] In alternative aspects, the invention may be defined according to the following list of preferred embodiments:

[0055] 1. A device for capturing CO2 from air, comprising:

[0056] (a) a cylinder having a circumferential wall centered about a vertical central axis, wherein the circumferential wall is at least partially permeable to air and comprises a solid CO2 sorbent;

[0057] (b) means for rotating said cylinder about said vertical axis;

[0058] (c) at least one adsorption chamber, the at least one adsorption chamber being delimited by a portion of the circumferential wall and a partition wall;

[0059] (d) at least one regeneration chamber, the at least one regeneration chamber being delimited by another portion of the circumferential wall and the partition wall;

[0060] (e) an inlet at one end of the circumferential wall for receiving air, and an outlet at the other end of the circumferential wall in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow from the inlet through the circumferential wall to the outlet;

[0061] (f) means for flowing stripping gas through said circumferential wall into said regeneration chamber;

[0062] (g) at least one outlet in the regeneration chamber for exhausting CO2; and

[0063] (h) A heating device for heating the regeneration chamber.

[0064] 2. The device according to embodiment 1, wherein the circumferential wall is composed of a microporous cushion layer and a macroporous top layer, wherein the pores of the macroporous top layer are coated with a solid CO2 adsorbent.

[0065] 3. The device according to embodiment 1 or 2 further includes a CO2 recycling device (i), wherein the CO2 recycling device (i) is configured to allow the stripping gas to flow through the circumferential wall into the regeneration chamber (d), wherein the recycling device includes a device for separating a product CO2 stream from a recycling stream, wherein the product CO2 stream is capable of being discharged through the outlet (g) for discharging CO2, and the recycling stream is returned to the regeneration chamber (d).

[0066] 4. The apparatus according to any one of the preceding embodiments, wherein the heating device (h) is capable of heating the solid CO2 adsorbent to a temperature in the range of 50°C-100°C, preferably to a temperature in the range of 60°C-85°C, most preferably to a temperature in the range of 67°C-75°C when positioned adjacent to or within the regeneration chamber.

[0067] 5. The device according to any of the preceding embodiments, wherein the heating device is capable of heating a stripping gas that flows through the circumferential wall into the regeneration chamber.

[0068] 6. The device according to any one of the preceding embodiments, comprising 1-20 adsorption chambers and 1-20 regeneration chambers, wherein the adsorption chambers and the regeneration chambers are alternately positioned in the cylinder.

[0069] 7. The device according to any one of the preceding embodiments, wherein the CO2 adsorbent is selected from the group consisting of bicarbonate-based adsorbents, amine-based adsorbents, and metal-organic frameworks.

[0070] 8. A method for capturing CO2 from air, comprising:

[0071] (iv) rotating a cylinder having a circumferential wall about a vertical central axis, wherein the circumferential wall is at least partially permeable to air and comprises a solid CO2 sorbent;

[0072] (v) providing an air flow through the circumferential wall at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent;

[0073] (vi) providing a stripping gas flow through the circumferential wall at the regeneration section at an elevated temperature to obtain a product stream comprising CO2 and a regenerated solid CO2 sorbent;

[0074] Wherein adsorption of CO2 by the solid CO2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO2 adsorbent.

[0075] 9. A method according to embodiment 8, wherein the stripping gas is provided by recycling from the product stream, wherein the product stream comprising CO2 obtained in (iii) is separated into a product CO2 stream and a recycling stream comprising the stripping gas, and the recycling stream is recycled to (iii).

[0076] 10. The method according to embodiment 8 or 9, further comprising:

[0077] (iv) heating the stripping gas to the elevated temperature prior to passing through the circumferential wall during (iii).

[0078] 11. The method according to any one of embodiments 8-10, wherein the method is performed using the apparatus according to any one of embodiments 1-7. DETAILED DESCRIPTION

[0079] The present invention provides a device and a method for capturing CO2 directly from the air. The device according to the invention is intended to be used by the method according to the invention. Likewise, the method according to the invention is intended to be performed in the device according to the invention. The device and method according to the invention employ a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent. Therefore, the present invention also relates to the use of such a membrane for capturing CO2 from the air. Anything disclosed herein for the method according to the invention applies equally to the device according to the invention and to the use according to the invention, and anything disclosed for the device according to the invention applies equally to the method according to the invention and to the use according to the invention.

[0080] The invention also relates to the use of a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid adsorbent for capturing gaseous substances other than carbon dioxide from the air.

[0081] The device

[0082] The device for capturing CO2 from air according to the present invention comprises:

[0083] (a) an at least partially air permeable membrane comprising a solid CO2 sorbent coated in the pores of the membrane;

[0084] (b) at least one adsorption chamber;

[0085] (c) at least one regeneration chamber;

[0086] (d) means for transferring the membrane from the adsorption chamber to the regeneration chamber and back;

[0087] (e) an inlet located on one side of the membrane for receiving air, and an outlet located on the other side of the membrane in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow from the inlet through the membrane to the outlet;

[0088] (f) means for flowing a stripping gas across the membrane into the regeneration chamber;

[0089] (g) at least one outlet in the regeneration chamber for exhausting CO2; and

[0090] (h) A heating device for heating the regeneration chamber.

[0091] "Device" may also be referred to as "system" or "apparatus". The core of the device according to the invention is a membrane consisting of a macroporous layer, the pores of which are coated with a solid CO2 adsorbent. Gases such as air and CO2 can flow through the membrane, and while other gaseous substances will permeate the membrane, CO2 molecules will be absorbed by the adsorbent. The membrane typically has an annular form, preferably a cylindrical or conveyor form.

[0092] Solid CO2 adsorbents are known in the art. Any material capable of adsorbing CO2 molecules at room temperature is suitable as a solid CO2 adsorbent. The adsorbent may also be referred to as an adsorbent. The adsorbent is capable of releasing the adsorbed CO2 molecules at an elevated temperature, preferably in the range of 50-100°C, preferably in the range of 60-85°C, and most preferably in the range of 67-75°C. The technician also found that Sanz-Pérez et al. teach the selection of suitable adsorbents in Chem. Rev. 2016, 116, 11840-11876, which is incorporated herein by reference. Preferably, the adsorbent is amine-based and / or bicarbonate-based. Such adsorbents are known in the art and include polyethyleneimine (PEI) and potassium bicarbonate (KHCO3). In addition, metal organic frameworks (MOFs) are suitable adsorbents for CO2.

[0093] The membrane is porous so that the gas flow can pass through the membrane. In the context of the present invention, the membrane may also be referred to as a "thin layer". The membrane suitable for use in the present invention can be prepared in any manner known in the art, for example, by growing the macroporous layer on a backing layer, such as a microporous layer or another porous layer. A suitable technique is plasma enhanced chemical vapor deposition (PEVCD), see, for example, WO2016 / 163878. In a preferred embodiment, the average pore size is in the range of 5nm-250nm, more preferably in the range of 10nm-50nm. The membrane typically includes an inert porous material, such as amorphous silicon, on which the adsorbent is coated. In this way, a thin film is formed, and air can flow through the thin film with a minimum pressure difference on the membrane. In a preferred embodiment, the macroporous layer is deposited on or covered on a backing layer. In one embodiment, the pad layer is a porous layer comprising small pores, for example having a diameter in the range of 50 μm-500 μm, preferably in the range of 100 μm-250 μm. In an alternative embodiment, the membrane consists of a microporous pad layer and a macroporous top layer, wherein the pores of the macroporous top layer are coated with a solid CO2 adsorbent. The pad layer serves as a support for the macroporous top layer, which can be grown on top of the pad layer. The pad layer is preferably formed by an inert metal mesh, such as a mesh formed by copper wire.

[0094] Preferably, the total thickness of the thin layer is in the range of 10 μm-250 μm, more preferably in the range of 15 μm-100 μm, most preferably in the range of 20 μm-50 μm. Such a thickness of the thin layer allows efficient passage of gases (air during adsorption, CO2 during regeneration) with minimal pressure drop across the membrane, while still being able to provide efficient adsorption of CO2 molecules contained in the air onto the adsorbent. An additional advantage of the thin layer is that the thin layer can be heated and cooled in a relatively short amount of time, which allows for rapid adsorption and regeneration cycles. Where a cushion layer is present, the cushion layer is preferably very thin, such as in the range of 1 μm-25 μm, preferably in the range of 5 μm-15 μm. The top layer may be slightly thicker, such as in the range of 5 μm-200 μm, preferably in the range of 10 μm-75 μm, most preferably in the range of 20 μm-50 μm.

[0095] Arranging the solid CO2 adsorbent into a thin layer forces the air to pass through the covered pores of the thin layer, thus maximizing the interaction between the CO2 molecules contained in the air and the adsorbent. This provides a significant advantage over a granular adsorbent bed (fluidized bed reactor) where the air can flow without contacting the adsorbent, thus reducing the interaction and lowering the adsorption efficiency. Furthermore, flowing air through a granular adsorbent bed requires more energy, typically in the form of a pressure difference between the inlet side of the bed and the outlet side of the bed.

[0096] Although the thin layer requires only a minimal pressure drop across the membrane, preferably the device also includes means to facilitate the flow of air through the membrane. Such means may, for example, take the form of a decompressor that can reduce the pressure within the membrane (e.g. the space confined within a cylinder or belt) on the permeate side of the membrane, i.e. within the adsorption chamber and preferably also within the regeneration chamber.

[0097] The thin layer can be positioned on a support layer having large holes in the side wall, such as a mechanical device (such as a rotating drum). Such a support layer can be made of stainless steel, and / or can be provided with holes with a diameter in the range of 0.1mm-50mm (such as 0.5mm-20mm). Multiple thin layers are stacked on top of each other. In this way, the air is forced to pass through multiple layers, thereby increasing the capacity of the membrane. The inventors have found that this can be achieved without compromising the low pressure drop required to achieve membrane permeation. Each of the layers can include a cushion layer and a top layer as defined herein. Preferably 1-5 thin layers are so positioned, more preferably, there are 1 or 2 thin layers. The size of the membrane is not critical for operating the present invention, and the size of the membrane can range from centimeters (for small devices) to several meters (for large industrial devices). For example, the diameter of a cylindrical membrane can range from 0.5cm to 100m, preferably from 1cm to 10m, more preferably from 5cm to 5m. The height of the membrane is also not critical to the present invention and can range from millimeters to several meters. For example, the height can range from 0.1 cm to 25 m, preferably from 0.5 cm to 10 m. These parameters can be adjusted entirely depending on the desired size of the device and the scale of the CO2 capture process.

[0098] The device according to the present invention comprises a device for conveying or moving the membrane through the various zones. The membrane typically takes the form of a closed loop, which rotates continuously when the device is in use. When the membrane moves, the membrane follows the trajectory of the loop. The various zones are located on the trajectory of the loop, and the various zones include at least one adsorption chamber and at least one regeneration chamber, as further defined below. In one embodiment further described below, the membrane ring has a cylindrical form, wherein the membrane is located on a circumferential wall, and the circumferential wall can be rotated to convey the membrane from one zone to the next. In another embodiment further described below, the membrane ring has the form of a belt that moves from one zone to another, much like a conveyor belt.

[0099] When moving, the membrane passes through at least two chambers, one adsorption chamber and one regeneration chamber. There may be more than one chamber of each type, such as 1-20 adsorption chambers and 1-20 regeneration chambers. Typically, the number of adsorption chambers and regeneration chambers is the same. In a preferred embodiment, the adsorption chambers and the regeneration chambers are alternately positioned around the trajectory of the membrane ring so that when the membrane is transported, the membrane passes through alternating adsorption chambers and regeneration chambers. In a particularly preferred embodiment, there is one adsorption chamber and one regeneration chamber.

[0100] The adsorption chamber and the regeneration chamber are zones through which the membrane passes. The chambers are delimited by partition walls that divide the volume around the moving membrane into multiple chambers or zones. The partition walls should allow the membrane to pass through when the membrane passes through them. Typically, the segment of the partition wall extends beyond the membrane and contains an opening for the membrane to pass through during the movement of the membrane. When passing through in this way, the connection between the moving membrane and the partition wall is preferably substantially airtight to avoid gas leakage between the adsorption chamber and the regeneration chamber as much as possible. In a preferred embodiment, at least CO2 is substantially avoided from leaking from the regeneration chamber to the adsorption chamber. In addition, more preferably, air is substantially avoided from leaking from the regeneration chamber to the adsorption chamber. CO2 leakage to the adsorption chamber will directly hinder the adsorbent from capturing CO2 from the air. On the other hand, air leakage to the regeneration chamber will lead to contamination of the CO2 stream (especially the CO2 product stream), which is disadvantageous for the current method, but can be solved by properly treating the product stream.

[0101] Thus, preferably, the device according to the present invention comprises a device for substantially airtightly sealing the adsorption chamber and the regeneration chamber during the passage of the membrane. Typically, such a device is arranged at an opening in the partition wall extending beyond the membrane for the passage of the membrane. Devices for airtight sealing are known in the art. In one embodiment, the airtight seal is achieved by a gas curtain, preferably an active nitrogen curtain, in which nitrogen is blown through the opening during rotation. Alternatively or additionally, the device is configured so that the regeneration chamber operates at a (slightly) reduced pressure compared to the adsorption chamber, so that any CO2 leakage from the regeneration chamber to the adsorption chamber is avoided. Gas leakage between the adsorption chamber and the regeneration chamber can also be avoided by providing a space between two adjacent chambers. CO2 leaking from the regeneration chamber will not contaminate the CO2-poor air in the adsorption chamber, but will eventually be located in the open space between the chambers and can be collected separately if desired.

[0102] Adsorption of CO2 molecules onto the adsorbent occurs at the adsorption chamber. During operation, the conditions within the adsorption chamber should be favorable for CO2 adsorption. The optimal conditions for CO2 adsorption may vary from adsorbent to adsorbent, and these optimal conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the present invention. Thus, air enters through the inlet and is allowed to flow through the membrane into the adsorption chamber. Since adsorption occurs during passage through the membrane, the air entering the adsorption chamber is depleted in CO2 (or CO2-poor). In other words, the CO2 concentration in the air is reduced compared to the incoming air received via the inlet. The CO2-poor air is discharged from the device according to the present invention through the outlet. The outlet is positioned in the adsorption chamber, on the opposite side of the membrane compared to the inlet. Typically, the outlet is positioned in the top of the bottom of the adsorption chamber so as not to interfere with the moving membrane. In a preferred embodiment, the number of inlets for receiving air and the number of outlets for discharging CO2-poor air are both equal to the number of adsorption chambers.

[0103] Regeneration of the loaded adsorbent (i.e., loaded with CO2 molecules) occurs at the regeneration chamber. Regeneration or desorption occurs by passing a stripping gas through the loaded adsorbent. Any known stripping gas for regenerating a loaded solid CO2 adsorbent can be used. The stripping gas preferably comprises one or more of CO2, steam, and an inert gas (such as nitrogen and helium). In one embodiment, the stripping gas is selected from the group consisting of nitrogen, steam, helium and CO2, preferably from the group consisting of steam and CO2. In the context of the present invention, the stripping gas preferably comprises CO2, preferably at least 80% by volume of CO2 (based on the total volume) or even at least 95% by volume of CO2 (based on the total volume), most preferably, the stripping gas is essentially composed of CO2, or in other words, most preferably, the stripping gas is CO2. During operation, the conditions in the regeneration chamber should be conducive to CO2 desorption. Optimal conditions for CO2 desorption may vary from adsorbent to adsorbent, these optimal conditions typically include ambient pressure and elevated temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at elevated temperature, whereby the device according to the invention comprises heating means capable of heating the regeneration chamber, the regeneration chamber being typically heated to a temperature in the range of 50°C-100°C, preferably in the range of 60°C-85°C, most preferably in the range of 67°C-75°C.

[0104] Thus, the stripping gas enters via the inlet and travels through the membrane into the regeneration chamber. Due to the desorption that occurs during passage through the membrane, the gas entering the regeneration chamber is enriched in CO2. In other words, the CO2 content in the gas is increased compared to the incoming stripping gas. In the case where pure CO2 is preferably used as stripping gas, the concentration of CO2 therein typically remains the same (about 100% by volume), but the absolute amount of CO2 molecules entering the regeneration chamber is increased. A product stream comprising CO2, typically consisting essentially of said CO2, is discharged from the device according to the invention through an outlet.

[0105] Alternative stripping gases may also be used. For example, steam and inert gases such as nitrogen and helium are known to be efficient stripping gases. In that case, preferably, the device includes a device for separating the spent stripping gas, which includes, for example, nitrogen and / or steam and desorbed CO2, into a CO2 stream and a stripping gas stream. Since CO2 is able to strip the loaded CO2 adsorbent, the incomplete separation where some CO2 remains in the stripping gas does not hinder the method. Methods for achieving such separation are known in the art. For example, CO2 can be removed from the steam by condensing the steam, after which the gaseous CO2 is discharged as a product stream, and the steam can be reused as a stripping gas after evaporation.

[0106] Preferably, a recycle is provided, wherein the stripping gas is circulated through the device. This is particularly advantageous in the case where the stripping gas consists essentially of CO2. In this case, the stripping gas still consists essentially only of CO2 after being used for regeneration. This used stripping gas is easily divided into a recycle stream that is reused for regeneration, and a product stream discharged from the device. This product stream consists essentially of CO2 that has been captured from the air. Preferably, the scale of the recycle is constant and sufficient to keep the loaded adsorbent regenerated so that all CO2 captured from the air is ultimately located in the product stream. This product stream then consists of CO2 captured from the air, which is a key product according to the method of the invention.

[0107] In a preferred embodiment, the heating means for heating the regeneration chamber is configured so that the stripping gas is heated before passing through the loaded adsorbent. The heated stripping gas will then ensure the appropriate conditions for desorption to occur. In the presence of CO2 recycle, preferably, the heating occurs after separation of the product stream, so that a smaller volume of gas needs to be heated.

[0108] In view of the low CO2 concentration in the air, typically a large amount of air should be blown through the device according to the invention to achieve a high yield of captured CO2. In order to ensure that such a large amount of air is introduced into the device, it is preferably implemented in an existing ventilation system or at a location where air flow naturally exists. This is the case, for example, in industrial processes where large temperature differences provide air flow, such as large-scale cooling processes.

[0109] In one embodiment, the device according to the invention further comprises a suction device for sucking air into the device, in particular into the adsorption chamber. Such suction devices are known in the art and include, for example, a ventilator or a fan. Such a suction device is arranged so that air can be sucked into the adsorption chamber.

[0110] The advantages of the invention are fully utilized in two preferred embodiments. The device according to the first preferred embodiment is in the form of a rotating cylinder, wherein the membrane is in the form of a cylindrical wall. The device according to the second preferred embodiment is in the form of a moving belt, wherein the membrane is in the form of a belt body. The devices according to these two embodiments are described in more detail below.

[0111] The device in the form of a rotating cylinder comprises:

[0112] (a) a cylinder having a circumferential wall centered about a vertical central axis, wherein the circumferential wall is at least partially permeable to air and comprises a solid CO2 sorbent;

[0113] (b) at least one adsorption chamber, the at least one adsorption chamber being delimited by a portion of the circumferential wall and a partition wall;

[0114] (c) at least one regeneration chamber, the at least one regeneration chamber being delimited by another portion of the circumferential wall and the partition wall;

[0115] (d) means for rotating said cylinder about said vertical axis;

[0116] (e) an inlet at one end of the circumferential wall for receiving air, and an outlet at the other end of the circumferential wall in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow from the inlet through the circumferential wall to the outlet;

[0117] (f) means for flowing stripping gas through said circumferential wall into said regeneration chamber;

[0118] (g) at least one outlet in the regeneration chamber for exhausting CO2; and

[0119] (h) A heating device for heating the regeneration chamber.

[0120] The core of the rotating cylinder device is a cylinder with a circumferential wall centered around a vertical axis. The circumferential wall of the cylinder includes a solid CO2 adsorbent. Gases (such as air and CO2) can flow through the circumferential wall. All of the above definitions of the membrane apply to the cylinder wall. The circumferential wall is porous to allow gas flow to pass through the wall. In a preferred embodiment, the average pore size is in the range of 5nm-250nm, more preferably in the range of 10nm-50nm.

[0121] The thin layer can be positioned on a mechanical device such as a rotating drum having large holes in the side wall. Such a drum can be made of stainless steel and / or can be provided with holes with a diameter in the range of 0.1mm-50mm (such as 0.5mm-20mm). A plurality of thin layers can be positioned on the rotating drum, each thin layer comprising a cushion layer and a top layer as defined herein. Preferably 1-5 thin layers are so positioned, more preferably there are 1 or 2 thin layers. In order to increase the contact area of ​​the air, preferably, the thin layer is positioned outside the rotating drum. The diameter of the circumferential wall is not critical for operating the present invention, and the diameter of the circumferential wall can range from centimeters (for small devices) to several meters (for large industrial devices). For example, the diameter can range from 0.5cm to 100m, preferably from 1cm to 10m, more preferably from 5cm to 5m. The height of the cylinder (i.e., the circumferential wall) is also not critical for the present invention, and the height can range from millimeters to several meters. For example, the height may range from 0.1 cm to 25 m, preferably from 0.5 cm to 10 m. These parameters can be adjusted entirely depending on the desired size of the device and the scale of the CO2 capture process.

[0122] The circumferential wall of the cylinder is centered around a vertical axis about which the circumferential wall can rotate. Thus, the central axis is located at the midpoint of the circle formed by the circumferential wall. The device according to the invention comprises means for rotating the cylinder around this vertical axis. Such devices are well known in the art.

[0123] When rotating, the circumferential wall passes through at least two chambers, one adsorption chamber and one regeneration chamber. There may be more than one chamber of each type, such as 1-20 adsorption chambers and 1-20 regeneration chambers. Typically, the number of adsorption chambers and regeneration chambers is the same. In a preferred embodiment, the adsorption chambers and the regeneration chambers are alternately positioned in the circumferential wall so that when the circumferential wall rotates, the circumferential wall passes through alternating adsorption chambers and regeneration chambers. In a particularly preferred embodiment, there is one adsorption chamber and one regeneration chamber.

[0124] The adsorption chamber and the regeneration chamber are located in the cylinder, and each is delimited by the circumferential wall and the partition wall, and the partition wall divides the internal space of the cylinder into a plurality of chambers. Typically, the partition wall has a plurality of segments extending radially from the central axis toward the circumferential wall, so that a wedge-shaped chamber is formed. Although the top of each wedge-shaped chamber located at the center of the cylinder (the segments of the partition wall are connected at the center) (i.e., the angle at which the two segments of the partition wall are connected) may be different, preferably, the tops of all adsorption chambers are equal and the tops of all regeneration chambers are equal. Most preferably, the tops of all chambers are equal. In a particularly preferred embodiment, there is one adsorption chamber and one regeneration chamber, and the top of each chamber is about 180°. An adjacent pair of adsorption chambers and regeneration chambers can share a common partition wall, but there may also be space between the partition wall delimiting the adsorption chamber and the partition wall delimiting the regeneration chamber.

[0125] The partition wall should allow the circumferential wall to pass through when the circumferential wall rotates. Typically, the segment of the partition wall extends beyond the circumferential wall and includes an opening for the circumferential wall to pass through during the rotation of the circumferential wall. When passing through in this way, the connection between the moving circumferential wall and the partition wall is preferably substantially airtight to avoid gas leakage between the adsorption chamber and the regeneration chamber as much as possible. In a preferred embodiment, CO2 is at least substantially avoided from leaking from the regeneration chamber to the adsorption chamber. In addition, more preferably, air is also substantially avoided from leaking from the adsorption chamber to the regeneration chamber. CO2 leakage to the adsorption chamber will directly hinder the adsorbent from capturing CO2 from the air. On the other hand, air leakage to the regeneration chamber will lead to contamination of the CO2 flow (especially the CO2 product flow), which is disadvantageous for the current method, but can be solved by properly treating the product flow.

[0126] Thus, preferably, the device according to the invention comprises means for substantially airtightly sealing the adsorption chamber and the regeneration chamber during rotation of the circumferential wall. Typically, such means are arranged in an opening in a partition wall extending beyond the circumferential wall, through which the circumferential wall moves during rotation. Means for airtight sealing are known in the art. In one embodiment the airtight sealing is achieved by a gas curtain, preferably an active nitrogen curtain, wherein nitrogen is blown through the opening during rotation. Alternatively or additionally, the device is configured so that the regeneration chamber operates at a (slightly) reduced pressure compared to the adsorption chamber, thereby avoiding any CO2 leakage from the regeneration chamber to the adsorption chamber. Gas leakage between the adsorption chamber and the regeneration chamber can also be avoided by providing a space between two adjacent chambers. Leakage of CO2 from the regeneration chamber will not contaminate the CO2-depleted air in the adsorption chamber, but will end up in the open space between the chambers and can be collected separately if desired.

[0127] Adsorption of CO2 molecules onto the adsorbent occurs at the adsorption chamber. During operation, the conditions within the adsorption chamber should be favorable for CO2 adsorption. The optimal conditions for CO2 adsorption may vary from adsorbent to adsorbent, and these optimal conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Thus, air enters through the inlet and is allowed to flow through the circumferential wall into the adsorption chamber. Since adsorption occurs during passage through the circumferential wall, the air entering the adsorption chamber is depleted in CO2 (or CO2-poor). In other words, the CO2 concentration in the air is reduced compared to the incoming air received via the inlet. The CO2-poor air is discharged from the device according to the invention through the outlet. The outlet is located in the adsorption chamber on the opposite side of the circumferential wall compared to the inlet. Typically, the outlet is located in the top of the bottom of the adsorption chamber so as not to interfere with the rotating circumferential wall. In a preferred embodiment, the number of inlets for receiving air and the number of outlets for discharging CO2-poor air are both equal to the number of adsorption chambers.

[0128] Regeneration of the loaded adsorbent (i.e., loaded with CO2 molecules) occurs at the regeneration chamber. Regeneration or desorption occurs by passing a stripping gas through the loaded adsorbent. Any known stripping gas for regenerating a loaded solid CO2 adsorbent may be used. The stripping gas preferably comprises one or more of CO2, steam and an inert gas (such as nitrogen and helium). In one embodiment, the stripping gas is selected from the group consisting of nitrogen, steam, helium and CO2, preferably from the group consisting of steam and CO2. In the context of the present invention, the stripping gas preferably comprises CO2, preferably at least 80% by volume of CO2 (based on the total volume) or even at least 95% by volume of CO2 (based on the total volume), most preferably, the stripping gas consists essentially of CO2, or in other words, most preferably, the stripping gas is CO2. During operation, the conditions within the regeneration chamber should be conducive to CO2 desorption. Optimal conditions for CO2 desorption may vary from adsorbent to adsorbent, these optimal conditions typically include ambient pressure and elevated temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at elevated temperature, whereby the device according to the invention comprises heating means capable of heating the regeneration chamber, typically to a temperature in the range of 50°C-100°C, preferably to a temperature in the range of 60°C-85°C, most preferably to a temperature in the range of 67°C-75°C.

[0129] In this way, the stripping gas passes through the circumferential wall into the regeneration chamber. Due to the desorption that occurs during the passage through the circumferential wall, the gas entering the regeneration chamber is enriched in CO2. In other words, the CO2 content in the gas is increased compared to the incoming stripping gas. In the case where pure CO2 is preferably used as stripping gas, the concentration of CO2 therein typically remains the same (about 100% by volume), but the absolute amount of CO2 molecules entering the regeneration chamber is increased. A product stream comprising CO2, typically consisting essentially of said CO2, is discharged from the device according to the invention through an outlet.

[0130] The device in the form of a conveyor belt comprises:

[0131] (a) a strip comprising a membrane as a separate layer, wherein the membrane is at least partially permeable to air and comprises a solid CO2 sorbent;

[0132] (b) at least one adsorption chamber;

[0133] (c) at least one regeneration chamber;

[0134] (d) means for conveying the strip through the adsorption chamber and the regeneration chamber;

[0135] (e) an inlet located on one side of the membrane for receiving air, and an outlet located on the other side of the membrane in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow from the inlet through the membrane to the outlet;

[0136] (f) means for flowing a stripping gas across the membrane into the regeneration chamber;

[0137] (g) at least one outlet in the regeneration chamber for exhausting CO2; and

[0138] (h) A heating device for heating the regeneration chamber.

[0139] The device according to this preferred embodiment comprises a membrane positioned on a mechanical device, a belt, which can be moved in a rotatable manner much like a conveyor belt. The belt comprises the membrane as a separate layer. The membrane is positioned on a support layer, wherein the pores of the macroporous layer comprise the solid CO2 adsorbent coated within the pores. Gases (such as air and CO2) can flow through the belt. All the above definitions of the membrane apply to the belt of this embodiment. In a preferred embodiment, the average pore size of the membrane is in the range of 5nm-250nm, more preferably in the range of 10nm-50nm.

[0140] The support layer of the strip (on which the membrane is positioned) may be made of stainless steel and / or may have holes with a diameter in the range of 0.1 mm-50 mm (such as 0.5 mm-20 mm). A plurality of thin layers may be positioned on the strip, each thin layer comprising a cushion layer and a top layer as defined herein. Preferably, 1-5 thin layers are so positioned, more preferably, there are 1 or 2 thin layers. In order to increase the contact area of ​​the air, preferably, the thin layers are positioned on the outside of the strip. The diameter of the strip is not critical for operating the present invention, and the diameter of the strip may range from centimeters (for small devices) to several meters (for large industrial devices). For example, the diameter may range from 0.5 cm to 100 m, preferably from 1 cm to 10 m, more preferably from 5 cm to 5 m. The width of the strip (i.e., of the membrane) is also not critical for the present invention, and the width may range from millimeters to several meters. For example, the height ranges from 0.1 cm to 25 m, preferably from 0.5 cm to 10 m. These parameters can be adjusted entirely depending on the desired size of the plant and the scale of the CO2 capture process.

[0141] The belt is capable of moving or conveying. The device according to the present invention includes a device for conveying the belt. Such devices are well known in the art. When being conveyed, the belt passes through at least two chambers, an adsorption chamber and a regeneration chamber. There may be more than one chamber of each type, such as 1-20 adsorption chambers and 1-20 regeneration chambers. Typically, the number of adsorption chambers and regeneration chambers is the same. In a preferred embodiment, the adsorption chambers and the regeneration chambers are alternately positioned around the belt so that when the belt moves, the belt passes through alternating adsorption chambers and regeneration chambers. In a particularly preferred embodiment, there is one adsorption chamber and one regeneration chamber.

[0142] The adsorption chamber and the regeneration chamber are located adjacent to the belt body and are each delimited by a portion of the belt body and a partition wall, the partition wall dividing the space around the belt body into a plurality of chambers. The chambers may be located inside or outside the belt body. An adjacent pair of adsorption chambers and regeneration chambers may share a common partition wall, but there may also be space between the partition wall delimiting the adsorption chamber and the partition wall delimiting the regeneration chamber.

[0143] The partition wall should allow the belt to pass through while it is being conveyed. Typically, a segment of the partition wall extends beyond the belt and includes an opening for the belt to pass through during the rotation of the belt. During such passage, the connection between the conveyor belt and the partition wall is preferably substantially airtight to avoid gas leakage between the adsorption chamber and the regeneration chamber as much as possible. In a preferred embodiment, CO2 leakage from the regeneration chamber to the adsorption chamber is at least substantially avoided. In addition, more preferably, air leakage from the adsorption chamber to the regeneration chamber is also substantially avoided. CO2 leakage to the adsorption chamber will directly hinder the capture of CO2 from the air by the adsorbent. On the other hand, air leakage to the regeneration chamber will lead to contamination of the CO2 flow (especially the CO2 product flow), which is disadvantageous for the current method, but can be solved by properly treating the product flow.

[0144] Thus, preferably, the device according to the invention comprises means for substantially airtightly sealing the adsorption chamber and the regeneration chamber during rotation of the belt. Typically, such means are arranged in an opening in a partition wall extending beyond the belt, through which the belt moves during rotation. Means for airtight sealing are known in the art. In one embodiment the airtight sealing is achieved by a gas curtain, preferably an active nitrogen curtain, wherein nitrogen is blown through the opening during rotation. Alternatively or in addition, the device is configured such that the regeneration chamber operates at a (slightly) reduced pressure compared to the adsorption chamber, thereby avoiding any CO2 leakage from the regeneration chamber to the adsorption chamber. Gas leakage between the adsorption chamber and the regeneration chamber can also be avoided by providing a space between two adjacent chambers. Leakage of CO2 from the regeneration chamber will not contaminate the CO2-depleted air in the adsorption chamber, but will end up in the open space between the chambers and can be collected separately if desired.

[0145] Adsorption of CO2 molecules onto the adsorbent occurs at the adsorption chamber. During operation, the conditions within the adsorption chamber should be favorable for CO2 adsorption. The optimal conditions for CO2 adsorption may vary from adsorbent to adsorbent, and these optimal conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Thus, air enters through an inlet and is allowed to flow through the membrane deposited on the strip into the adsorption chamber. Since adsorption occurs during passage through the strip, the air entering the adsorption chamber is depleted in CO2 (or CO2-poor). In other words, the CO2 concentration in the air is reduced compared to the incoming air received via the inlet. The CO2-poor air is discharged from the device according to the invention through an outlet. The outlet is located in the adsorption chamber on the opposite side of the strip compared to the inlet. Typically, the outlet is located in the top of the bottom of the adsorption chamber so as not to interfere with the moving strip. In a preferred embodiment, the number of inlets for receiving air and the number of outlets for discharging CO2-poor air are both equal to the number of adsorption chambers.

[0146] Regeneration of the loaded adsorbent (i.e., loaded with CO2 molecules) occurs at the regeneration chamber. Regeneration or desorption occurs by passing a stripping gas through the loaded adsorbent. Any known stripping gas for regenerating a loaded solid CO2 adsorbent can be used. The stripping gas preferably comprises one or more of CO2, steam and an inert gas (such as nitrogen and helium). In one embodiment, the stripping gas is selected from the group consisting of nitrogen, steam, helium and CO2, preferably from the group consisting of steam and CO2. In the context of the present invention, the stripping gas preferably comprises CO2, preferably at least 80% by volume of CO2 (based on the total volume) or even at least 95% by volume of CO2 (based on the total volume), most preferably, the stripping gas is essentially composed of CO2, or in other words, most preferably, the stripping gas is CO2. During operation, the conditions in the regeneration chamber should be conducive to CO2 desorption. Optimal conditions for CO2 desorption may vary from adsorbent to adsorbent, these optimal conditions typically include ambient pressure and elevated temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at elevated temperature, whereby the device according to the invention comprises heating means capable of heating the regeneration chamber, the regeneration chamber being typically heated to a temperature in the range of 50°C-100°C, preferably in the range of 60°C-85°C, most preferably in the range of 67°C-75°C.

[0147] In this way, the stripping gas travels through the belt into the regeneration chamber. Due to the desorption that takes place during the passage through the belt, the gas entering the regeneration chamber is enriched in CO2. In other words, the CO2 content in the gas is increased compared to the incoming stripping gas. In the case where pure CO2 is preferably used as stripping gas, the concentration of CO2 therein typically remains the same (about 100% by volume), but the absolute amount of CO2 molecules entering the regeneration chamber is increased. A product stream comprising CO2, typically consisting essentially of said CO2, is discharged from the device according to the invention through the outlet.

[0148] method

[0149] The method according to the invention is for capturing CO2 from air and comprises:

[0150] (i) moving a membrane comprising a macroporous layer from an adsorption section to a regeneration section, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent;

[0151] (ii) providing an air flow through the membrane at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent;

[0152] (iii) providing a stripping gas stream through the membrane at the regeneration section at an elevated temperature to obtain a product stream comprising CO 2 and a regenerated solid CO 2 adsorbent.

[0153] Herein, the adsorption of CO2 by the solid CO2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and the regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO2 adsorbent. Thus, the adsorption section corresponds to the adsorption chamber in the device according to the present invention, and the regeneration section corresponds to the regeneration chamber in the device according to the present invention.

[0154] It is noteworthy that (i), (ii) and (iii) occur simultaneously rather than successively, so that a continuous process can be performed. During (ii), adsorption occurs, i.e., CO2 molecules present in the air are adsorbed by the solid CO2 adsorbent, so that the air that has passed through the membrane is depleted of CO2 (or is CO2-lean) and the adsorbent is loaded with CO2. The movement of (i) ensures that the loaded adsorbent is transferred from the adsorption section to the regeneration section. During (iii), regeneration occurs, i.e., CO2 molecules adsorbed to the solid CO2 adsorbent are desorbed by the stripping gas, so that the stripping gas that has passed through the membrane is enriched in CO2, and the adsorbent is regenerated and can be used for another adsorption stage in (ii).

[0155] The conditions during (ii) allow adsorption to occur, which conditions may vary from one adsorbent to another. These conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the method according to the invention. The conditions during (iii) allow adsorption to occur, which conditions include elevated temperature. Elevated temperature herein refers to a temperature that is higher than the temperature during (ii). The optimal conditions for regeneration or CO2 desorption may vary from one adsorbent to another, and these optimal conditions typically include ambient pressure, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at an elevated temperature in the range of 50°C-100°C, preferably in the range of 60°C-85°C, and most preferably in the range of 67°C-75°C. For operation of the method according to the invention, the solid CO2 adsorbent positioned on the membrane should be at the elevated temperature, and it is unimportant whether its surroundings are also at the elevated temperature. After all, desorption occurs within the solid CO2 adsorbent. The elevated temperature is preferably provided by a stripping gas at the desired elevated temperature, and this warm stripping gas subsequently heats the solid CO2 sorbent during (iii). The method according to the invention preferably further comprises a step (iv), wherein the stripping gas is heated to the elevated temperature before passing through the membrane during (iii).

[0156] During operation, the membrane moves so that the adsorbent travels from the adsorption chamber to the regeneration chamber, to the adsorption chamber to the regeneration chamber, and so on. Thus, the adsorbent migrates from an adsorption environment (i.e., the adsorption section) at a reduced temperature (typically ambient temperature) to a regeneration environment (i.e., the regeneration section) at an increased temperature. Thus, when the portion of the membrane is located in the adsorption chamber, the adsorbent is loaded with CO2. The adsorbent loaded with CO2 is then conveyed toward the regeneration chamber, where the CO2 molecules are desorbed and the adsorbent is regenerated. The regenerated adsorbent is then rotated toward the adsorption chamber and used again to capture CO2 from the air. In this article, a sequence of an adsorption phase and a regeneration phase is referred to as a cycle. This multi-step sequence can continue for an extended period of time, during which CO2 is captured from the air in the adsorption chamber, desorbed in the regeneration chamber, and finally enters the CO2 product stream.

[0157] During a complete cycle, the membrane passes through at least one adsorption section and one regeneration section. A plurality of such sections is also possible, consistent with the adsorption chamber and regeneration chamber defined for the device according to the invention. The speed at which the membrane moves depends very much on the size of the membrane, the size (length) of the adsorption section and the regeneration section, and the number of adsorption sections and regeneration sections arranged around the membrane. For example, the speed may be such that the residence time of the solid adsorbent in a single adsorption section is 0.05s-1min, preferably 0.1s-10s, more preferably 0.5s-5s. Thus, having more sections means that the membrane can move slower. Due to the thinness of the adsorption layer in the membrane, the adsorbent may reach saturation with CO2 molecules within 0.1s-60s, preferably 0.1s-10s, more preferably 0.5s-5s. Regeneration typically occurs on the same time scale. In view of rapid saturation, the residence time of the adsorbent in each of the chambers is preferably short, preferably 0.1 second to 60 seconds, more preferably 0.1 second to 10 seconds, most preferably 0.5 second to 5 seconds.

[0158] In a preferred embodiment, the stripping gas is provided by recycling from the product stream, wherein the product stream comprising CO2 obtained in (iii) is divided into a product CO2 stream, and a recycling stream comprising stripping gas, and the recycling stream is recycled to (iii). Thus, the method according to the present invention preferably further comprises a step (v), wherein the product stream comprising CO2 obtained in (iii) is divided into a product CO2 stream, and a recycling stream comprising stripping gas.

[0159] For a preferred embodiment of the device in the form of a rotating cylinder, the method according to the invention comprises:

[0160] (i) rotating a cylinder having a circumferential wall about a vertical central axis, wherein the circumferential wall is at least partially permeable to air and is a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent;

[0161] (ii) providing an air flow through the circumferential wall at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent;

[0162] (iii) providing a stripping gas flow through the circumferential wall at the regeneration section at an elevated temperature to obtain a product stream comprising CO 2 and a regenerated solid CO 2 sorbent.

[0163] Herein, adsorption of CO 2 by the solid CO 2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO 2 adsorbent.

[0164] It is noteworthy that (i), (ii) and (iii) occur simultaneously rather than successively, so that a continuous process can be performed. During (ii), adsorption occurs, i.e., CO2 molecules present in the air are adsorbed by the solid CO2 adsorbent, so that the air that has passed through the circumferential wall is depleted of CO2 (or is CO2-lean) and the adsorbent is loaded with CO2. During (iii), regeneration occurs, i.e., CO2 molecules adsorbed to the solid CO2 adsorbent are desorbed by the stripping gas, so that the stripping gas that has passed through the circumferential wall is enriched in CO2, and the adsorbent is regenerated and can be used for another adsorption stage in (ii).

[0165] The conditions during (ii) allow adsorption to occur, which conditions may vary from one adsorbent to another. These conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the method according to the invention. The conditions during (iii) allow adsorption to occur, which conditions include elevated temperature. Elevated temperature herein refers to a temperature that is higher than the temperature during (ii). The optimal conditions for regeneration or CO2 desorption may vary from one adsorbent to another, and these optimal conditions typically include ambient pressure, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at an elevated temperature in the range of 50°C-100°C, preferably in the range of 60°C-85°C, most preferably in the range of 67°C-75°C. For operation of the method according to the invention, the solid CO2 adsorbent positioned on the circumferential wall should be at the elevated temperature, and it is unimportant whether its surroundings are also at an elevated temperature. After all, desorption occurs within the solid CO2 adsorbent. The elevated temperature is preferably provided by a stripping gas at the desired elevated temperature, and this warm stripping gas subsequently heats the solid CO2 sorbent during (iii). The method according to the invention here preferably also comprises a step (iv), wherein the stripping gas is heated to the elevated temperature before passing through the circumferential wall during (iii).

[0166] During operation, the circumferential wall rotates so that the adsorbent travels from the adsorption chamber to the regeneration chamber, to the adsorption chamber to the regeneration chamber, and so on. Thus, the adsorbent migrates from an adsorption environment (i.e., the adsorption section) at a reduced temperature (typically ambient temperature) to a regeneration environment (i.e., the regeneration section) at an increased temperature. Thus, the adsorbent is loaded with CO2 when the portion of the circumferential wall is located in the adsorption chamber. The adsorbent loaded with CO2 is then rotated toward the regeneration chamber, where the CO2 molecules are desorbed and the adsorbent is regenerated. The regenerated adsorbent is then rotated toward the adsorption chamber and is used again to capture CO2 from the air. In this article, a sequence of an adsorption phase and a regeneration phase is referred to as a cycle. This multi-step sequence can last for an extended period of time, during which CO2 is captured from the air in the adsorption chamber, desorbed in the regeneration chamber, and finally enters the CO2 product stream.

[0167] During a complete rotation, the circumferential wall passes through at least one adsorption section and one regeneration section. A plurality of such sections is also possible, in accordance with the adsorption chamber and the regeneration chamber defined for the device according to the invention. The speed at which the circumferential wall rotates depends strongly on the diameter of the circumferential wall, the size (length) of the adsorption section and the regeneration section, and the number of adsorption sections and regeneration sections arranged around the circumferential wall. For example, the rotation speed may be such that the residence time of the solid adsorbent in a single adsorption section is 0.05s-1min, preferably 0.1s-10s, more preferably 0.5s-5s. Thus, having more sections means that the circumferential wall can rotate more slowly.

[0168] Due to the thinness of the adsorption layer on the circumferential wall, the adsorbent can reach saturation with CO2 molecules within 0.1 second to 60 seconds, preferably 0.1 second to 10 seconds, more preferably 0.5 second to 5 seconds. Regeneration typically occurs on the same time scale. In view of the rapid saturation, the residence time of the adsorbent in each of the chambers should be short, preferably 0.1 second to 60 seconds, more preferably 0.1 second to 10 seconds, most preferably 0.5 second to 5 seconds.

[0169] For a preferred embodiment of the device in the form of a conveyor belt, the method according to the invention comprises:

[0170] (i) conveying a belt which is at least partially permeable to air and on which is located a membrane consisting of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent, through an adsorption section and a regeneration section;

[0171] (ii) providing an air flow through the belt body at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent;

[0172] (iii) providing a stripping gas stream through the belt at the regeneration section at an elevated temperature to obtain a product stream comprising CO 2 and a regenerated solid CO 2 sorbent.

[0173] Herein, adsorption of CO 2 by the solid CO 2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO 2 adsorbent.

[0174] It is noteworthy that (i), (ii) and (iii) occur simultaneously rather than successively, so that a continuous process can be performed. During (ii), adsorption occurs, i.e., CO2 molecules present in the air are adsorbed by the solid CO2 adsorbent, so that the air that has passed through the strip is depleted of CO2 (or is CO2-lean) and the adsorbent is loaded with CO2. During (iii), regeneration occurs, i.e., CO2 molecules adsorbed to the solid CO2 adsorbent are desorbed by the stripping gas, so that the stripping gas that has passed through the strip is enriched in CO2, and the adsorbent is regenerated and can be used for another adsorption stage in (ii).

[0175] The conditions during (ii) allow adsorption to occur, which conditions may vary depending on the adsorbent. These conditions typically include ambient pressure and temperature, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the method according to the invention. The conditions during (iii) allow adsorption to occur, which conditions include elevated temperature. Elevated temperature herein refers to a temperature that is higher than the temperature during (ii). The optimal conditions for regeneration or CO2 desorption may vary from adsorbent to adsorbent, and these optimal conditions typically include ambient pressure, although deviations from the optimal conditions may occur without significantly impairing the adsorption efficiency of the device according to the invention. Optimal results are obtained by carrying out the desorption at an elevated temperature in the range of 50°C-100°C, preferably in the range of 60°C-85°C, and most preferably in the range of 67°C-75°C. For operation of the method according to the invention, the solid CO2 adsorbent positioned on the strip should be at the elevated temperature, and it is unimportant whether its surroundings are also at an elevated temperature. After all, desorption occurs within the solid CO2 adsorbent. The elevated temperature is preferably provided by a stripping gas at the desired elevated temperature, and this warm stripping gas subsequently heats the solid CO2 sorbent during (iii). The method according to the invention preferably also comprises a step (iv) in which the stripping gas is heated to the elevated temperature before passing through the strip during (iii).

[0176] During operation, the belt is moved so that the adsorbent travels from the adsorption chamber to the regeneration chamber, to the adsorption chamber to the regeneration chamber, and so on. Thus, the adsorbent migrates from an adsorption environment (i.e., the adsorption section) at a reduced temperature (typically ambient temperature) to a regeneration environment (i.e., the regeneration section) at an increased temperature. Thus, the adsorbent is loaded with CO2 when the portion of the belt is located in the adsorption chamber. The adsorbent equipped with CO2 is then rotated toward the regeneration chamber, where the CO2 molecules are desorbed and the adsorbent is regenerated. The regenerated adsorbent is then rotated toward the adsorption chamber and is used again to capture CO2 from the air. In this article, a sequence of an adsorption phase and a regeneration phase is referred to as a cycle. This multi-step sequence can last for an extended period of time, during which CO2 is captured from the air in the adsorption chamber, desorbed in the regeneration chamber, and finally enters the CO2 product stream.

[0177] During a complete cycle, the belt passes through at least one adsorption section and one regeneration section. A plurality of such sections is also possible, in accordance with the adsorption chamber and the regeneration chamber defined for the device according to the invention. The speed at which the belt moves depends very much on the length of the trajectory of the loop (or the length of the belt), the size (length) of the adsorption and regeneration sections, and the number of adsorption and regeneration sections arranged around the belt. For example, the speed may be such that the residence time of the solid adsorbent in a single adsorption section is 0.05s-1min, preferably 0.1s-10s, more preferably 0.5s-5s. Thus, having more sections means that the belt can move more slowly.

[0178] Due to the thinness of the adsorption layer, the adsorbent can reach saturation with CO2 molecules within 0.1 seconds to 10 seconds, preferably within 0.5 seconds to 5 seconds. Regeneration typically occurs on the same time scale. In view of the rapid saturation, the residence time of the adsorbent in each of the chambers should be short, preferably 0.1 seconds to 10 seconds, preferably 0.5 seconds to 5 seconds.

[0179] use

[0180] As explained above, the present invention focuses on the use of a membrane consisting of a porous layer (also referred to herein as a "thin layer") for capturing gaseous molecules, in particular CO2, from air, wherein the pores of the porous layer are coated with a solid CO2 adsorbent. Herein, the membrane refers to a macroporous layer as further defined herein. In one embodiment, the membrane comprises a porous layer instead of a macroporous layer. Thus, the present invention also relates to the use of a membrane consisting of a porous layer (typically a macroporous layer), wherein the pores of the layer are coated with a solid adsorbent, to capture gaseous substances from air. Herein, the adsorbent is selectable with respect to the gaseous substance to be captured. The skilled person is aware of such adsorbents and understands how to select an adsorbent.

[0181] Although it is particularly preferred to use the membrane to capture CO2, as explained above, other gaseous substances may also be captured using the membrane according to the invention. Preferred substances include sulfur oxides and nitrogen oxides, preferably SO x and / or NO x Adsorbents of choice for these materials are known in the art and include calcium and copper oxides (e.g., CaO x , CuO x ).

[0182] The membrane is porous so that the gas flow can pass through the membrane. Preferably, the gas flow is perpendicular to the membrane. In a preferred embodiment, the average pore size is in the range of 5nm-250nm, more preferably in the range of 10nm-50nm. In a preferred embodiment, the membrane consists of a porous thin film membrane layer, wherein the pores of the layer are covered with a solid CO2 adsorbent. The membrane may include a pad, such as a microporous backing layer, which can be used as a support for the macroporous top layer. The microporous pad can be grown on top of the microporous pad. The pad is preferably formed by an inert metal mesh, such as a mesh formed by copper wire. The membrane typically includes an inert porous material, such as amorphous silicon, on which the adsorbent is coated. In this way, a thin film is formed, and air can flow through the thin film with a minimum pressure difference across the membrane.

[0183] In even further embodiments, the membrane is used to capture gaseous molecules from a gas mixture other than air. The molecules to be captured may be present in small or large amounts, such as up to 15% by volume or up to 10% by volume. In a preferred embodiment, the gas mixture is characterized by a low content of gaseous molecules to be captured, the content being typically less than 0.5% by volume, or even less than 0.1% by volume. The present invention is suitable for removing such gaseous molecules present in low amounts, as illustrated by CO2 removal from air (air having a CO2 content of only 0.04% by volume). In a preferred embodiment, CO2 is captured from the gas mixture.

[0184] The use according to the invention is preferably carried out with the device according to the invention. Likewise, the use according to the invention preferably employs the method according to the invention.

[0185] The device according to the present invention is a great improvement over known devices for capturing CO2 from air. First, due to its high efficiency, enough CO2 can be captured to provide an economically viable method. In other words, the operating cost (OPEX) of the device according to the present invention is significantly reduced compared to the known device. In addition, the device according to the present invention provides a pure CO2 product stream, so that no further separation technology is required. The OPEX of the present invention has been compared with the OPEX of the prior art system for capturing CO2 from air using an aqueous solution of sodium hydroxide (see Keith et al., A process for capturing CO2 from thermasphere, Volume 2, 2018, Pages 1573–1594). Among them, the prior art device is estimated to operate at $172 per ton of CO2 for the first plant, reduced to $134 per ton of CO2 for the nth plant, and the present device is estimated to operate at $75 per ton of CO2 for the first plant, reduced to $58 per ton of CO2 for the nth plant. The energy cost is estimated to be reduced from $33 / ton of CO2 for the prior art device to $15 / ton of CO2 for the device according to the present invention.

[0186] In addition, the capital expenditure (CAPEX) of the device according to the present invention is significantly reduced relative to the prior art device. See Keith et al., for example, a prior art system for capturing CO2 from air using aqueous sodium hydroxide is calculated to be $1.1 billion for a plant that captures 1 megaton of CO2 per year ($700 million to build the plant and $400 million in indirect costs). The CAPEX of the device according to the present invention is calculated to be $480 million, which includes $300 million for construction and $180 million in indirect costs. In contrast to the device of Keith et al., the device according to the present invention essentially requires an air contactor unit.

[0187] A further advantage of the device according to the invention is that it is fully scalable to the needs of the user. The parameters that can be adjusted for a specific situation include the size of the membrane (e.g. the diameter of the circumferential wall, the height of the cylinder, the width and length of the belt), the speed of the movement (e.g. the rotation speed of the cylinder, the conveying speed of the belt), the amount of chambers and the amount of membranes superimposed on each other. Especially for its application during the energy transition (where society is slowly turning to renewable energy sources), the scalable system can be implemented and adapted to the requirements of many situations, including industrial-scale devices for capturing millions of tons of CO2 per year, and small-scale civilian devices for capturing exponentially smaller amounts of CO2. BRIEF DESCRIPTION OF THE DRAWINGS

[0188] Figure 1-Figure 5 Preferred embodiments of the device and method according to the invention are depicted.

[0189] Figure 1 A cylindrical device is depicted, wherein a membrane (a) in the form of a circumferential wall is positioned around a vertical axis (a2). Within the circumferential wall, an adsorption chamber (b) and a regeneration chamber (c) separated by a dividing wall (solid black) are positioned. On the adsorption side, the device comprises an inlet (e7) for receiving air (A), and on the other side of the circumferential wall (a), in the bottom of the adsorption chamber (b), the device comprises an outlet (e2) for discharging CO2-depleted air. On the regeneration side, the device comprises an inlet (f1) for receiving stripping gas (B), and on the other side of the circumferential wall (a), in the bottom of the regeneration chamber (c), the device comprises an outlet (g) for discharging a product stream containing CO2.

[0190] Figure 2 A device is depicted having a number of adsorption chambers (b) and regeneration chambers (c) arranged around a membrane (a), the membrane (a) being in the form of a circumferential wall positioned around a vertical axis (a2). Each adsorption chamber (b) has an inlet (e1) for receiving air (A) and an outlet (e2) on the other side of the circumferential wall (a) for discharging CO2-depleted air. Each regeneration chamber (c) has an inlet (f1) for receiving stripping gas (B) and an outlet (g) on ​​the other side of the circumferential wall (a) for discharging a product stream containing CO2.

[0191] Figure 3A belt (a) is depicted on which a membrane is positioned. The belt houses a conveyor (d) for circulating the belt through the adsorption chamber (b) and the regeneration chamber (c). An adsorption chamber (b) and a regeneration chamber (c) are positioned, the adsorption chamber (b) and the regeneration chamber (c) being separated by a partition wall (solid black). On the adsorption side, the device comprises an inlet (e7) for receiving air and an outlet (e2) for discharging CO2-depleted air on the other side of the membrane (a). On the regeneration side, the device comprises an inlet (f1) for receiving the stripping gas (B) and an outlet (g) for discharging a product stream containing CO2 on the other side of the membrane (a).

[0192] Figure 4 A schematic diagram showing an embodiment of the method of the present invention is shown. Figure 4 The CO2 extractor depicted in is a combined representation of the membrane, the adsorption section and the regeneration section, which is typically formed by the device according to the present invention. At a certain temperature (e.g., 20°C), air enters the CO2 extractor. CO2 adsorption occurs at the adsorption section, thereby obtaining a membrane with a loaded solid CO2 adsorbent, and CO2-lean air (e.g., at a temperature of 30°C), which is discharged from the CO2 extractor. The stripping gas at an elevated temperature (e.g., at 70°C) is directed through the membrane at the regeneration section of the CO2 extractor to regenerate the adsorbent, thereby obtaining a product stream containing CO2 (net CO2 outflow), typically at a slightly reduced temperature, for example, at 60°C. A portion of the product stream is recycled and reused as stripping gas after heating to the desired stripping temperature.

[0193] Figure 5 A membrane consisting of a stack of thin films (lower layer, cross-shaped shading) is shown, each having small holes (e.g., 100μm-200μm diameter) that allow air to pass through. Each film is covered with a porous cover (upper layer, line-shaped shading) in the pores of which the adsorbent is coated. The rectangular shape at the bottom represents a support layer on which the thin films are positioned. Such a support layer can be, for example, a rotating drum or a moving belt. The support layer has large holes (spaces between the rectangular shapes), e.g., 0.1mm-5mm. Arrows represent air flow or stripping gas flow through the membrane to load or regenerate the adsorbent in the porous top layer.

Claims

1. A device for capturing CO2 from air, comprising: (a) a cylinder comprising a membrane in the form of a circumferential wall centered around a central axis, wherein the membrane is at least partially permeable to air, wherein the membrane consists of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent, and wherein the central axis is located at the midpoint of a circle formed by the circumferential wall; (b) at least one adsorption chamber, the at least one adsorption chamber being delimited by a portion of the circumferential wall and a partition wall; (c) at least one regeneration chamber, the at least one regeneration chamber being delimited by another portion of the circumferential wall and the partition wall; (d) means for rotating the cylinder about the central axis to transfer the membrane from the adsorption chamber to the regeneration chamber and back; (e) an inlet located on one side of the circumferential wall for receiving air, and an outlet located in the adsorption chamber on the other side of the circumferential wall for discharging CO2-lean air, wherein the device is configured to allow air to flow from the inlet to the outlet through the circumferential wall; (f) means for flowing stripping gas through said circumferential wall into said regeneration chamber; (g) at least one outlet in the regeneration chamber for exhausting CO2; and (h) a heating device for heating the regeneration chamber; Wherein, the adsorption chamber and the regeneration chamber are alternately positioned in the circumferential wall.

2. A device for capturing CO2 from air, comprising: (a) a tape body comprising a membrane as a separate layer, wherein the membrane is at least partially permeable to air, wherein the membrane consists of a macroporous layer, wherein the pores of the macroporous layer are coated with a solid CO2 adsorbent; (b) at least one adsorption chamber, the at least one adsorption chamber being delimited by a portion of the membrane and a partition wall; (c) at least one regeneration chamber, wherein the at least one regeneration chamber is bounded by another portion of the membrane and a dividing wall; (d) means for conveying said belt through said at least one adsorption chamber and said at least one regeneration chamber; (e) an inlet located on one side of the membrane for receiving air, and an outlet located on the other side of the membrane in the adsorption chamber for discharging CO2-lean air, wherein the device is configured to allow air to flow through the membrane from the inlet to the outlet; (f) means for flowing a stripping gas through the membrane into the regeneration chamber; (g) at least one outlet in the regeneration chamber for exhausting CO2; and (h) a heating device for heating the regeneration chamber; Wherein, the adsorption chamber and the regeneration chamber are alternately positioned around the belt body.

3. The device according to claim 1 or 2, wherein: The membrane takes the form of a closed ring which is arranged to rotate continuously when the device is in use.

4. The device according to claim 1 or 2, wherein: The membrane comprises a stack of thin films comprising pores having a diameter in the range of 50 μm - 500 μm in diameter, and each thin film is covered with a macroporous material comprising the adsorbent.

5. The device according to claim 1 or 2, further comprising a CO2 recycling device (j), wherein the CO2 recycling device (j) is configured to flow the stripping gas through the membrane into the regeneration chamber (c), wherein The CO 2 recycle device (j) comprises means for separating a product CO 2 stream from a recycle stream, wherein the product CO 2 stream can be discharged through the outlet (g) for discharging CO 2 , and the recycle stream is returned to the regeneration chamber (c).

6. The device according to claim 1 or 2, wherein: The heating device is capable of heating the solid CO2 sorbent to a temperature in the range of 50°C-100°C when positioned adjacent to or within the regeneration chamber.

7. The device according to claim 6, wherein: The heating device is capable of heating the solid CO2 sorbent to a temperature in the range of 60°C-85°C when positioned adjacent to or within the regeneration chamber.

8. The device according to claim 6, wherein: The heating device is capable of heating the solid CO2 sorbent to a temperature in the range of 67°C-75°C when positioned adjacent to or within the regeneration chamber.

9. The device according to claim 1 or 2, wherein: The heating device is capable of heating a stripping gas that flows through the membrane into the regeneration chamber.

10. The device according to claim 1 or 2, comprising 1 to 20 adsorption chambers and 1 to 20 regeneration chambers.

11. The device according to claim 1 or 2, wherein: The CO2 adsorbent is selected from the group consisting of bicarbonate-based adsorbents, amine-based adsorbents and metal-organic frameworks.

12. The device according to claim 1 or 2, wherein: The junction between the adsorption chamber and the regeneration chamber is gas-tight.

13. The device according to claim 1 or 2, wherein: The heating device is capable of heating the regeneration chamber to a temperature higher than the temperature of the adsorption chamber.

14. A method for capturing CO2 from air, comprising: (i) moving a membrane consisting of a macroporous layer, the pores of which are coated with a solid CO2 adsorbent, from an adsorption section to a regeneration section, wherein the membrane is at least partially permeable to air; (ii) providing an air flow through the membrane at the adsorption section to obtain CO2-lean air and loaded solid CO2 adsorbent; (iii) providing a stripping gas stream through the membrane at the regeneration section at an elevated temperature to obtain a product stream comprising CO2 and a regenerated solid CO2 adsorbent; wherein adsorption of CO2 by the solid CO2 adsorbent occurs at the adsorption section to obtain a loaded adsorbent, and regeneration of the loaded adsorbent occurs at the regeneration section to obtain a regenerated solid CO2 adsorbent, wherein the method is performed using an apparatus according to any one of claims 1 to 13, and wherein steps (i), (ii) and (iii) occur simultaneously so that a continuous process can be performed.

15. The method according to claim 14, wherein: The moving of step (i) involves rotating a cylinder having a circumferential wall about a central axis, wherein the circumferential wall comprises the membrane, and wherein the central axis is located at the midpoint of a circle formed by the circumferential wall.

16. The method according to claim 14, wherein: The moving of step (i) involves conveying a belt through the adsorption chamber and the regeneration chamber, wherein the belt comprises the membrane.

17. The method according to claim 14 or 15, wherein: The stripping gas is provided by recycling from the product stream, wherein the product stream comprising CO2 obtained in (iii) is separated into a product CO2 stream and a recycle stream comprising the stripping gas, and the recycle stream is recycled to (ii).

18. The method according to claim 14 or 15, further comprising: (iv) during (iii), heating the stripping gas to the elevated temperature before the stripping gas passes through the membrane.

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