Sorbent, CO2 separation plant and method for operating the same

Abstract

The present invention relates to a sorbent (1) for the reversible adsorption of CO2, comprising a) a rollable sorbent carrier (8) and b) a sorbent (6), wherein the sorbent (6) is arranged on a surface (3) of the sorbent carrier (8) and is designed to reversibly adsorb CO2 and wherein the sorbent carrier (8) has a diameter (D) in a range from 0.5 cm to 20 cm.

Description

State of the art

[0001] The present invention relates to a sorbent with which CO2 can be reversibly bound, a CO2 separation plant and a method for operating the same.

[0002] One greenhouse gas responsible for global warming is carbon dioxide (CO2). There is therefore a worldwide effort to isolate CO2 from the air and then either convert it into other products through synthesis, or to store it permanently in liquid or solid form, for example in underground storage facilities. There are systems that can remove and isolate CO2 from the air on a large scale. Such systems are known as direct air capture systems (DAC systems) and comprise an adsorption or desorption chamber (ADC) into which ambient air is introduced, from which CO2 is selectively chemically or physically bound to a liquid or solid sorbent (also called an adsorbent), thus removing it from the air. When the adsorbed CO2 is needed, it is desorbed from the sorbent by heating and, if necessary, negative pressure, and can then either be stored or reused.

[0003] The disadvantage of conventional sorbents is that they are stationary, supported on a carrier and present as an adsorption bed in the ADC, with the ADC being permanently installed in the DAC system. While this makes it possible to carry out CO2 adsorption and CO2 desorption in the same chamber and thus stationary at the same location, they cannot be carried out at the same time or at any independent points in time. This can result in energy losses because the sorption processes are difficult to control over time. Furthermore, replacing the sorbents, consisting of carrier and sorbent, is only possible as a whole. In other words, the entire adsorption bed must be replaced. Disclosure of the invention

[0004] The sorbent according to the invention, on the other hand, is characterized by its high mobility and can be easily moved or transported (independently) from one location to another. This also makes it easy to replace a defective sorbent.

[0005] The sorbent according to the invention is designed for the reversible adsorption of CO2 and comprises a sorbent carrier and a sorbent. For the purposes of the present invention, a sorbent refers to a single sorbent, i.e., a unit consisting of a single sorbent carrier and a sorbent arranged on the surface of the sorbent carrier. The sorbent carrier therefore does not consist of individual particles that are aggregated to form an agglomerate, but is, in a figurative sense, a single particle. The sorbent carrier has a diameter in a range of 0.5 cm to 20 cm, where the diameter is understood to be the longest distance between two points on the sorbent carrier. The sorbent can be arranged on the surface of the sorbent carrier using conventional processes, for example, by impregnation.

[0006] Essential to the invention is that the sorbent carrier is rollable. For the purposes of the present invention, rollable refers to a sorbent carrier that has at least one curved surface. The sorbent carrier can be easily moved over this curved surface, which is convex toward the surroundings, without significant frictional resistance.

[0007] The sorbent is not specifically limited, as long as it is designed to reversibly adsorb and / or absorb CO2. For the sake of simplicity, adsorption in the context of the present invention refers to both adsorption of CO2 and absorption of CO2. Both types of binding of CO2 to the sorbent are expressly possible.

[0008] The rolling ability of the sorbent carrier according to the invention allows the sorbent to be selectively moved and transported. This is advantageous when the adsorption of CO2 and the desorption of CO2 are to be carried out in spatially separated areas. The sorbent carrier is thus easily transportable without high energy expenditure, so that the adsorption and desorption of CO2 can also be carried out independently of each other in time, which is only possible if the loaded sorbent can be stored separately from the unloaded sorbent. The temporal equalization of the sorption processes is advantageous because it allows access to energy reserves that are available for a limited time.

[0009] For example, the desorption process of CO2 from the sorbent requires high temperatures and the application of negative pressure. These processes require high energy loads. These processes are best performed when there is a surplus of energy and can be suspended during periods when energy is needed for other purposes, is scarce, or is only available at high prices. The sorbent can therefore be stored sufficiently in both the discharged and the charged state, allowing it to wait for appropriately energetically favorable times for the upcoming sorption process.

[0010] The diameter of 0.5 cm to 20 cm represents a very good compromise between excellent rollability and CO2 sorption capacity. These are also handy shapes, allowing multiple sorbents to be easily differentiated and separated from one another, for example, if a sorbent exhibits damage that can be detected by reduced rollability. Furthermore, the sorbent carrier is small enough to provide sufficient surface area for the sorbent.

[0011] The subclaims show preferred developments of the invention.

[0012] According to a preferred embodiment, the sorbent carrier is round, cylindrical, or ellipsoidal. These carrier shapes all have the advantage of being characterized by particularly good rolling ability, which is somewhat better for a round and cylindrical shape than for an ellipsoidal shape, which exhibits a more wobbly movement pattern, but is nevertheless sufficient to move the sorbent carrier within a short period of time.

[0013] Further preferably, in light of a compromise between rollability and large surface area for absorbing sorbent, the sorbent carrier has a diameter in a range of 0.7 cm to 10 cm and in particular of 0.8 cm to 5 cm.

[0014] Preferably, the carrier material of the sorbent carrier is selected from zeolites, polymer-based ion exchange resins and mixtures thereof, since these materials can be easily synthesized in the desired size.

[0015] More preferably, the sorbent (adsorbent / absorbent) is selected from AEATPMS ([N-(2-aminoethyl)-3-aminopropyl]trimethoxysilane), APDES (3-aminopropylmethyldiethoxysilane), NFC (nanofibrillated cellulose) and mixtures thereof, since these sorbents are characterized by a high sorption capacity of CO2.

[0016] According to a further advantageous development, the sorbent carrier has indentations (depressions) on its surface, and the sorbent is located in the indentations. The indentations increase the surface area of the sorbent carrier, allowing it to absorb more sorbent. This improves the efficiency of the sorbent. It is advantageous if the sorbent is located in the indentations in such a way that the indentations are not completely filled with the sorbent, as this gives the CO2 a larger contact surface with the sorbent and allows it to bind more effectively to it. In addition, CO2 bound in the indentations can remain better bound to the sorbent during transport of the sorbent without being loosened and released by mechanical action.

[0017] Further advantageously, the diameter of the invaginations is 50 to 1000 µm, in particular 100 to 800 µm, and especially 200 to 500 µm. The diameter of the invaginations is understood to be the greatest distance between two points of an invagination. If the diameter is in the range of 50 to 1000 µm, a large amount of sorbent can be applied to the surface of the invaginations. If the diameter is in the range of 100 to 800 µm or even 200 to 500 µm, this has the additional effect of improving the flow of CO2 through the invaginations, thus binding more CO2 in the same unit of time. A sorbent designed in this way is characterized by further increased efficiency.

[0018] To desorb CO2 from the sorbent of the sorbent, the sorbent must be heated to a high temperature. This is best achieved when the sorbent is characterized by even, good heat distribution. This heat distribution can be particularly well improved by incorporating a hollow space inside the sorbent carrier and at least partially filling the cavity with a heat transfer medium. Materials that heat up quickly and release heat very quickly are suitable as heat transfer media. Water is particularly suitable for this purpose because the use of water has another advantageous effect: the water becomes at least partially gaseous at the intended desorption temperature. In the gaseous state, the water is very well distributed inside the sorbent carrier and, when condensed, releases its energy to the condensation site of the sorbent carrier.A so-called "heat-pipe" effect is observed. Since the desorption temperature is around the boiling point of water, water is particularly preferred due to its particularly good heat redistribution.

[0019] According to a further advantageous development, the sorbent carrier has an identification code. This allows each individual sorbent carrier to be distinguished from another, which is advantageous should one of the sorbent carriers be identified due to a defect or reduced efficiency. This allows the sorbent carrier to be easily located using its identification code and removed from the sorption process.

[0020] Also described according to the invention is a CO2 separation system, which is designed in particular as a DAC system and comprises an adsorption chamber (hereinafter: AK) and a desorption chamber (hereinafter: DK). The CO2 separation system according to the invention differs from the DAC system according to the invention only in the CO2-containing gas, which in a CO2 separation system originates from any CO2-containing gas, such as the exhaust gas from a gas fuel cell, whereas in a DAC system it originates from air. Otherwise, however, the systems are essentially structurally identical.

[0021] The AK is connected to the DK via a desorption conveying channel (hereinafter: DK), and the DK is connected to the AK via an adsorption conveying channel (hereinafter: AFK). The AK and the DK are spatially separated from one another. The DFK leads from the AK to the DK, and the AFK leads from the DK to the AK. The CO2 separation system serves to sorb CO2 from any CO2-containing gas, such as exhaust gas from another plant or air, and for this purpose comprises at least one sorbent as described above. It goes without saying that the CO2 separation system also comprises two or more sorbents and, advantageously, a plurality of sorbents that are identical or differ in terms of the sorbent carrier and / or sorbent, since this allows CO2 adsorption from the CO2-containing gas to be carried out more efficiently.

[0022] Preferably, the AC or the DK, or both the AC and the DK, can be operated in a countercurrent fashion. In the AC, this has the advantage of maximizing the absorption of incoming CO2. In the DK, this has the advantage that the loaded sorbent introduced into the DK is preheated by the unloaded sorbent discharged from the DK. Both designs have energy advantages.

[0023] The advantages, advantageous effects and further developments described for the sorbent according to the invention also apply to the CO2 separation plant according to the invention.

[0024] In order to avoid pressure losses, a vacuum lock is advantageously provided at an inlet of the DK and / or at an outlet of the DK.

[0025] To further improve the CO2 sorption processes, the DK advantageously comprises a heating element, a vacuum device, and a CO2 outlet, while the AK comprises a gas inlet and a gas outlet. In the case of a DAC system, the gas inlet is designed as an air inlet and the gas outlet as an air outlet. Structurally, this results in essentially no difference.

[0026] The heating element serves to bring the sorbent to the necessary desorption temperature of CO2 from the sorbent, whereby the released CO2 can be sucked out of the DK by the vacuum device.

[0027] The CO2 obtained after desorption and any water separation can be fed into further processes or simply stored. The gas inlet and outlet of the AC are used to introduce CO2-containing gas (including ambient air, as in the case of a DAC system) into the AC for CO2 adsorption. A blower or pump can be advantageous for this purpose.

[0028] A further advantageous development provides that one or more intermediate storage devices are provided in the DFK and / or in the AFK for storing the sorbent loaded with CO2 and / or for storing the discharged sorbent.

[0029] According to a further advantageous development, the CO2 separation system can comprise a scanning device. This embodiment is particularly advantageous if the sorbent carrier has an identification code, which is in particular in the form of a barcode or QR code.

[0030] According to a further advantageous embodiment, the CO2 separation system can also include a weighing device for weighing the sorbent. The weighing can be used to determine the amount of CO2 adsorbed per sorbent. The weighing process can be carried out over several sorption cycles, allowing the efficiency of each sorbent to be monitored. Sorbents characterized by a decreasing CO2 adsorption capacity can be removed from the CO2 separation system and replaced.

[0031] Furthermore, the invention also describes a method for operating a CO2 separation plant. The method is suitable for operating the CO2 separation plant disclosed above. For this purpose, the CO2 separation plant comprises an AK and a DK, which are connected to one another via a DFK from the AK to the DK and via an AFK from the DK to the AK. The DK comprises a heating element, a vacuum device, and a CO2 outlet, and the AK comprises a gas inlet and a gas outlet. The CO2 separation plant further comprises at least one sorbent as described above.

[0032] The process is characterized by the following process steps: a) flow of CO2-containing gas into the AC, b) adsorption of CO2 from the gas onto the sorbent of the sorbent, c) conveying the CO2-laden sorbent via the DK into the DK, d) desorbing CO2 from the sorbent in the DK, and e) conveying the discharged sorbent to the AC. It is also self-evident that two or more identical or different sorbents according to the invention can be used in the process in order to increase efficiency. Advantageously, a large number of sorbents are used, and among these, in particular identical sorbents (same sorbent, same sorbent carrier, same size and shape), since the adsorption and desorption conditions (e.g. temperature in the DK, flow rate of CO2-containing gas in the AC, and negative pressure in the DK) can then be optimized for the corresponding sorbent.

[0033] By spatially separating the AK from the DK and providing a sorbent with a rollable sorbent carrier, a temporal equalization between the adsorption process and the desorption process can be achieved. The two sorption processes can therefore be carried out at different times. This has advantages in terms of energy costs, since the energy-intensive desorption can be carried out at a time when, firstly, sufficient energy is available and, secondly, the energy is available more cheaply (in the event of an energy surplus in the system), and this is independent of the adsorption process. The sorbent can also be stored temporarily, either in a loaded or unloaded state. This means that, if necessary, more CO2 can be adsorbed from the CO2-containing gas than can be desorbed at the same time.

[0034] Particularly preferred is the sorbent circulating between the AC and the DK, including any intermediate storage steps. This circulation further increases the efficiency of the CO2 separation plant.

[0035] Preferably, the AC or the DK, or both the AC and the DK, can be operated in a countercurrent fashion. In the AC, this has the advantage of maximizing the absorption of incoming CO2. In the DK, this has the advantage that the loaded sorbent introduced into the DK is preheated by the unloaded sorbent discharged from the DK. Both designs have energy advantages.

[0036] One or more intermediate storage devices for storing the CO2-laden sorbent and / or for storing the discharged sorbent can also be provided in the circulation circuit described above. The method thus preferably also comprises a step of storing the CO2-laden sorbent and / or a step of storing the discharged sorbent. According to this embodiment, the CO2 sorption processes can be carried out even more effectively independently of one another.

[0037] The method also advantageously includes a step of weighing the loaded sorbent and the unloaded sorbent. This allows the amount of adsorbed CO2 to be monitored. This allows conclusions to be drawn about the efficiency of the process and, based on this, process parameters to be optimized. Furthermore, each individual sorbent can be tested for its effectiveness, and any less functional sorbents can be removed from the process.

[0038] Further advantageously, the method includes a step of identifying the sorbent via its identification code. This enables more precise monitoring of the sorbent's efficiency.

[0039] Particularly preferred is a combination of the two above steps—weighing the loaded sorbent and the unloaded sorbent and identifying the sorbent via its identification code—and the method comprises a further step of removing a defective sorbent from the CO2 separation system. Defective sorbents can be identified, for example, by a reduced CO2 release content. Short description of the drawings

[0040] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 a sorbent according to a first embodiment, Fig. 2 a section of the sorbent from Fig. 1 and Fig. 3 a DAC system according to a second embodiment. Embodiments of the invention

[0041] Only the essential elements and components of the present invention are illustrated in the figures. All other elements and components have been omitted for clarity. Preferably, all identical components, elements, and / or units are provided with the same reference numerals in all figures.

[0042] Fig. Figure 1 shows a detailed cross-sectional view of a sorbent 1 according to a first embodiment. The sorbent 1 comprises a sorbent carrier 8 with a surface 3 surrounding a cavity 2.

[0043] The surface 3 of the sorbent carrier 8 has depressions, i.e., indentations 4, which enlarge the surface 3 of the sorbent carrier 8. The indentations 4 have, in particular, a diameter Dd of 200 to 500 µm, which is measured at the widest point, i.e., the distance connecting the furthest apart points. A sorbent 6 is present on the surface 3 of the sorbent carrier 8, and thus in particular on the surface of the indentations 4. The sorbent 6 can be deposited on the surface 3 of the sorbent carrier 8 or impregnated thereon. The sorbent 6 is one that can reversibly bind CO2 from the air. If the sorbent 6 is present in the invaginations 4, CO2 bound in the invaginations 4 can also remain better bound to the sorbent 6 during the transport of the sorbent 1 without being dissolved and released by mechanical action.

[0044] The sorbent carrier 8 has a rollable shape and is, as shown here, spherical, i.e., round. However, it can also be ellipsoidal or cylindrical. Rather, the sorbent carrier 8 always has at least one curved surface, which appears as a rounded shape that is convex toward its surroundings. Due to the curved, round surface 3, the sorbent carrier 8 is characterized by a high rollability, which determines its mobility and thus also its transportability.

[0045] The sorbent carrier 8 has a diameter D in a range of 0.5 to 20 cm, with the diameter D being determined between the two most distant points of the sorbent carrier 8. This provides the largest possible surface 3 on which the sorbent 6 can be present, while ensuring good rollability and identifiability, so that as much CO2 as possible can be bound per sorbent 1.

[0046] As already explained above, the surface 3 of the sorbent carrier 8 surrounds the cavity 2. The cavity 2 can be partially filled with a heat transfer medium, so that the desorption of CO2 can be improved by evenly distributing the required temperature in the sorbent 1. This is particularly the case when water is used as the heat transfer medium, since the water evaporates due to the applied temperature and condenses at colder points of the sorbent carrier 8, whereby condensation heat is released to the sorbent carrier 8 and the sorbent carrier 8 heats up at the location of the water condensation. This effect is called the heat pipe effect.

[0047] The sorbent carrier 8 may additionally have an identification mark to distinguish it from other sorbent carriers 8.

[0048] Fig. 2 shows a section of the sorbent 1 from Fig. 1. Shown in detail is an indentation 4 on the surface 3 of the sorption carrier 1. Reference numeral 6, in turn, designates the sorbent present on the surface of the indentation. Arrows indicate passing air from which CO2 is to be adsorbed onto the sorbent 6. The shape of the indentation 4 results in a further advantage: the air is drawn into the indentation by vortex flow, allowing for more efficient adsorption of CO2 from the air. This also works particularly well when the diameter Dd of the indentation is in the range of 100 to 800 µm, and in particular in the range of 200 to 500 µm.

[0049] Fig. 3 shows a CO2 separation plant, which is designed here as an example in the form of a DAC plant 10, according to a second embodiment, which also illustrates a method for operating the CO2 separation plant designed as a DAC plant 10.

[0050] The DAC system 10 comprises an AK 11 and a DK 12, which are connected via a DFK 13 from the AK 11 to the DK 12 and via an AFK 14 from the DK 12 to the AK 11.

[0051] This results in a type of circulation circuit in which the sorbent 1 according to the invention can circulate. One or more intermediate storage devices can also be provided for storing the CO2-laden sorbent 1 and / or for storing the discharged sorbent 1. If such intermediate storage devices are provided, the method outlined here can thus preferably also include a step of storing the CO2-laden sorbent 1 and / or a step of storing the discharged sorbent 1, resulting in energy-related advantages.

[0052] The AK 11 comprises an air inlet 15 and an air outlet 16, with air without CO2 or at least with a reduced CO2 content exiting the air outlet 16. Ambient air serves as the air that is fed to the air inlet 15 via a fan 17.

[0053] The DK 12 is equipped with a heating element 18 and a vacuum device (not shown) so that, as illustrated by the arrow at the top of the DK 12, CO2 can be removed from the DK.

[0054] Vacuum locks 19 may be provided at the inlet of the DK 12 and at the outlet of the DK 12.

[0055] The DAC system 10 further comprises a plurality of sorbents 1, which, as in Fig. 1 and Fig. 2, and comprise a rollable sorbent carrier and a sorbent for the reversible adsorption (and absorption) of CO2. The sorbents 1 circulate through the DAC system via circulation lines 20a and 20b.

[0056] When air in AK 11 encounters discharged sorbent 1, the sorbent of sorbent 1 adsorbs CO2 from the air. Residual air (without or with reduced CO2 content) is discharged from AK 11 through air outlet 16. The loaded sorbents 1a are conveyed via DFK 13 to DK 12, where they enter DK 12 via vacuum lock 19 and are heated to desorption temperature. Released CO2 can be discharged from DK 12 and is available for further processes.

[0057] Discharged sorbent 1 exits the DK 12 via the vacuum lock 19 and returns to the AK 11 via AFK 14, where it is again available for CO2 adsorption after circulation.

[0058] The DAC system shown here is not only characterized by the spatial separation of the DK 12 and the AK 11, but also by the fact that the desorption and adsorption processes can be carried out separately in time, ideally when sufficient energy is available for desorption. This is made possible by the specifically designed sorbent 1, so that the DAC system 10 is distinguished by excellent energy management combined with very good CO2 filter capacity and efficiency.

[0059] Preferably, AK 11 or DK 12, or AK 11 and DK 12, can be operated in a countercurrent fashion. In AK 11, this has the advantage that incoming CO2 can be absorbed as effectively as possible. In DK 12, this has the advantage that the loaded sorbent introduced into DK 12 is preheated by the discharged sorbent 1 discharged from DK 12. This results in further energy-saving advantages.

Claims

[1] Sorbent (1) for the reversible adsorption of CO2, comprising: - a rollable sorbent carrier (8) and - a sorbent (6), wherein the sorbent (6) is arranged on a surface (3) of the sorbent carrier (8) and is designed to reversibly adsorb CO2 and wherein the sorbent carrier (8) has a diameter (D) in a range from 0.5 cm to 20 cm. [2] Sorbent (1) according to claim 1, wherein the sorbent carrier (8) is round or cylindrical or ellipsoidal. [3] Sorbent (1) according to claim 1 or 2, wherein the sorbent carrier (8) has a diameter (D) in a range from 0.7 cm to 10 cm and in particular from 0.8 cm to 5 cm. [4] Sorbent (1) according to one of the preceding claims, wherein a carrier material of the sorbent carrier (8) is selected from zeolites, polymer-based ion exchange resins and mixtures thereof. [5] Sorbent (1) according to one of the preceding claims, wherein the sorbent (6) is selected from AEATPMS ([N-(2-aminoethyl)-3-aminopropyl]trimethoxysilane), APDES (3-aminopropylmethyldiethoxysilane), NFC (nanofibrillated cellulose) and mixtures thereof. [6] Sorbent (1) according to one of the preceding claims, wherein the sorbent carrier (8) has indentations (4) on its surface (3) and the sorbent (6) is arranged in the indentations (4). [7] Sorbent (1) according to claim 6, wherein a diameter (Dd) of the invaginations (4) is 50 to 1000 µm, in particular 100 to 800 µm and in particular 200 to 500 µm. [8] Sorbent (1) according to one of the preceding claims, wherein the sorbent carrier (8) has a cavity (2) in the interior and the cavity (2) is at least partially filled with a heat transfer medium, in particular with water. [9] Sorbent (1) according to one of the preceding claims, wherein the sorbent carrier (8) has an identification mark. [10] CO2 separation plant, comprising an adsorption chamber (11) and a desorption chamber (12) which are connected to one another via a desorption conveying channel (13) from the adsorption chamber (11) to the desorption chamber (12) and via an adsorption conveying channel (14) from the desorption chamber (12) to the adsorption chamber (11), wherein the CO2 separation plant further comprises at least one sorbent (1) according to one of the preceding claims. [11] CO2 separation plant according to claim 10, wherein a vacuum lock (19) is present at an inlet of the desorption chamber (12) and / or at an outlet of the desorption chamber (12). [12] CO2 separation plant according to claim 10 or 11, wherein the desorption chamber (12) comprises a heating element (18), a vacuum device and a CO2 outlet and wherein the adsorption chamber (11) comprises a gas inlet. [13] CO2 separation system according to one of claims 10 to 12, designed as a direct air capture system, wherein the adsorption chamber (11) comprises an air inlet (15) and an air outlet (16). [14] CO2 separation plant according to one of claims 10 to 13, further comprising a scanning device for detecting an identification code of the sorbent (1) and / or a weighing device for weighing the sorbent (1). [15] A method for operating a CO2 separation plant, comprising an adsorption chamber (11) and a desorption chamber (12), which are connected to one another via a desorption conveying channel (13) from the adsorption chamber (11) to the desorption chamber (12) and via an adsorption conveying channel (14) from the desorption chamber (12) to the adsorption chamber (11), wherein the desorption chamber (12) comprises a heating element (18), a vacuum device and a CO2 outlet and the adsorption chamber (11) comprises a gas inlet and a gas outlet and wherein the CO2 separation plant further comprises at least one sorbent (1) according to one of claims 1 to 9, the method comprising the steps: - Inflow of CO2-containing gas into the adsorption chamber (11) - Adsorption of CO2 from the gas to the sorbent (6) of the sorbent (1) - conveying the sorbent (1a) loaded with CO2 via the desorption conveying channel (13) into the desorption chamber (12), - Desorbing CO2 from the sorbent (1) in the desorption chamber (12) and - Conveying the discharged sorbent (1) to the adsorption chamber (11). [16] The method according to claim 15, wherein the sorbent (1) circulates between the adsorption chamber (11) and the desorption chamber (12). [17] The method of claim 15 or 16, further comprising a step of storing the CO2-loaded sorbent and / or a step of storing the discharged sorbent. [18] Method according to one of claims 15 to 17, further comprising a step of weighing the loaded sorbent (1a) and the unloaded sorbent (1). [19] Method according to one of claims 15 to 18, comprising a step of identifying the sorbent (1) via its identification code. [20] Method according to one of claims 15 to 19 comprising the steps: - Weighing the loaded sorbent (1a) and the unloaded sorbent (1) - Identifying the sorbent (1) via its identification code and - Removing a defective sorbent (1) from the CO2 separation plant.

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