Installation and method for separation of carbon dioxide from the ambient air

Abstract

The invention relates to an installation (10) for separation of carbon dioxide from the ambient air. The installation (10) comprises an adsorption chamber (12) for binding of carbon dioxide from the ambient air in a sorbent (80), a desorption chamber (14) for release of the carbon dioxide bound in the sorbent (80), and a cooling chamber (16) for cooling of the sorbent (80) after the release of the carbon dioxide bound in the sorbent (80). Heating means for heating of the sorbent (80) are disposed in the desorption chamber (14). The installation (10) further comprises a continuous belt (20) which encompasses or bears the sorbent (80), and a drive element (84) set up to move the conveyor belt (20) through the adsorption chamber (12), the desorption chamber (14) and the cooling chamber (16). The invention further relates to a method for separation of carbon dioxide from the ambient air using such an installation (10).

Description

[0001] Description

[0002] Plant and process for separating carbon dioxide from the ambient air

[0003] The invention relates to a plant for separating carbon dioxide from the ambient air and to a method for separating carbon dioxide from the ambient air using such a plant according to the preamble of the independent patent claims.

[0004] The need to slow global climate change, which is being accelerated by greenhouse gas emissions, is extremely urgent. Above all, the increase in atmospheric carbon dioxide levels must be sustainably reduced. To reduce the carbon dioxide content in the ambient air and achieve climate neutrality, not only must carbon dioxide emissions be reduced, but unavoidable carbon dioxide emissions must also be compensated accordingly. A well-known method for separating carbon dioxide from the ambient air is the so-called "direct air capture process," in which ambient air is passed through an adsorption chamber, and the carbon dioxide contained in the ambient air is at least partially separated from the ambient air. Such processes are suitable for reducing the carbon dioxide content of the atmosphere and thus counteracting climate change.The development of powerful and efficient processes for separating carbon dioxide from the atmosphere is essential. One possible approach is the use of chemisorption for carbon dioxide capture. In this process, the carbon dioxide is chemically bound and subsequently released from the sorption material by heating and reducing the pressure level. This concentrates the released carbon dioxide and feeds it into an intermediate storage facility or a subsequent process step that requires carbon dioxide as a feedstock.

[0005] The energy efficiency of the sorption material during the heating and cooling phases is crucial for the amount of energy required and thus for the acceptance of the technology. Generally, a large portion of the system is thermally involved in the sorption and subsequent desorption of carbon dioxide, which negatively impacts the energy balance of the process. In addition, the sorbent is subjected to negative pressure during the desorption phase, which further increases the energy demand in state-of-the-art processes.

[0006] Most known processes for separating carbon dioxide from ambient air employ a cyclic process using a combination of pressure and temperature changes. In a first process step, carbon dioxide present in the atmospheric air is bound in a sorption element, thereby reducing the carbon dioxide content in the atmospheric air. The carbon dioxide bound in the sorption element can be released again in a second process step and either stored or fed into another process in which the released carbon dioxide is required as a feedstock. The development of suitable adsorption materials and their technical implementation in appropriate adsorption systems should enable efficient and energetically effective carbon dioxide capture.

[0007] One challenge is the development of efficient adsorption systems in which the sorption elements are technically arranged and / or designed in such a way that, on the one hand, the adsorption and desorption of carbon dioxide proceeds optimally and, on the other hand, a comparatively cost-effective plant concept can be implemented. In particular, the heating and cooling phases influence the process costs, while the design of the sorption element and the process chamber influence the plant costs.

[0008] A disadvantage of such discontinuously operating systems, however, is their high complexity. Sealing and heating the sorption chamber, as well as generating a vacuum, require considerable design effort. Furthermore, cyclical temperature changes and the high heat capacity of the system lead to low energy efficiency.

[0009] WO 2020 / 148460 A1 discloses a system and a method for capturing carbon dioxide from ambient air. The system comprises an at least partially air-permeable membrane containing a solid sorbent for absorbing carbon dioxide; at least one sorption chamber; at least one regeneration chamber; means for transporting the membrane from the sorption chamber to the regeneration chamber; and an inlet for absorbing air located at one end of the membrane and an outlet for discharging carbon dioxide-enriched air located at the other end of the membrane in the sorption chamber. The system is configured to allow air to flow through the membrane from the inlet to the outlet.The system further comprises means for stripping gas through the membrane into the regeneration chamber; at least one outlet for venting carbon dioxide located in the regeneration chamber; and heating means for heating the regeneration chamber.

[0010] WO 2020 / 046864 A1 describes a carbon dioxide scrubber for a building comprising an adsorption chamber through which an adsorption air stream is passed, a regeneration chamber through which a regeneration air stream is passed, and a partition wall separating the adsorption chamber from the regeneration chamber. A carbon dioxide sorbent bed extends across the adsorption chamber and the regeneration chamber. The carbon dioxide sorbent bed is configured to adsorb carbon dioxide from the adsorption air stream into the sorbent bed and to release carbon dioxide from the carbon dioxide sorbent bed into the regeneration air stream.

[0011] WO 2019 / 165 151 A1 discloses a system and method for passively collecting atmospheric carbon dioxide. The system comprises a collection chamber having a first opening and a sorbent regeneration system. The system also comprises a collection body connected to and movable through a support structure. The collection body contains a sorbent material and is movable through the support structure to be in a collection configuration in which at least a portion of the collection body is in contact with a natural airflow outside the harvesting chamber such that atmospheric carbon dioxide is captured by the sorbent material, and in a release configuration in which at least a portion of the collection body containing captured carbon dioxide is processed by the regeneration system within the harvesting chamber such that captured carbon dioxide is released to form an enriched gas.

[0012] The invention is based on the object of increasing the energy efficiency of a plant for separating carbon dioxide from the ambient air and overcoming the disadvantages known from the prior art.

[0013] This object is achieved by a system for separating carbon dioxide from the ambient air, which comprises an adsorption chamber for binding carbon dioxide from the ambient air in a sorbent, a desorption chamber for releasing the carbon dioxide bound in the sorbent, and a cooling chamber for cooling the sorbent after the release of the carbon dioxide bound in the sorbent, as well as an endless belt that encloses or carries the sorbent and a drive element that is configured to move the endless belt through the adsorption chamber, the desorption chamber, and the cooling chamber. Heating means for heating the sorbent are arranged in the desorption chamber.

[0014] The system according to the invention enables a comparatively simple and cost-effective separation of carbon dioxide from the ambient air. In particular, the continuous circulation of the endless belt ensures that the absorption, desorption, and cooling of the endless belt as a carrier of the sorbent occur simultaneously in corresponding sections of the endless belt, thus avoiding the constant heating, evacuation, and cooling of a sorption chamber. Rather, ideal conditions for the adsorption and subsequent desorption of carbon dioxide can be set in the adsorption chamber and the desorption chamber, respectively. Furthermore, the energy requirement can be drastically reduced compared to known solutions, since not the entire sorption chamber needs to be heated and cooled, but only the endless belt and the sorbent.The cooling chamber enables rapid cooling of the endless belt after desorption of the carbon dioxide, so that a corresponding section of the endless belt can be cooled over a short distance to a temperature which subsequently enables optimal adsorption of carbon dioxide.

[0015] The additional features listed in the dependent claims enable advantageous improvements and further developments of the plant for separating carbon dioxide from the ambient air listed in the independent claim.

[0016] In a preferred embodiment of the invention, the heating means in the desorption chamber comprise an infrared emitter. An infrared emitter can be used to specifically introduce high-energy radiation into the endless belt to heat the sorbent to a desorption temperature of at least 90°C. It is not necessary to heat the entire desorption chamber to the desorption temperature; it is sufficient to locally heat the endless belt and the sorbent operatively connected to the endless belt to the desorption temperature.

[0017] Alternatively or additionally, it is advantageous for the heating means in the desorption chamber to comprise a microwave emitter. A microwave emitter can be used to introduce high-energy radiation into the endless belt in a targeted manner to heat the sorbent to a desorption temperature of at least 90°C. It is not necessary to heat the entire desorption chamber to the desorption temperature; it is sufficient to locally heat the endless belt and the sorbent in active contact with the endless belt to the desorption temperature. Microwave radiation is particularly suitable for exciting water molecules on or in the endless belt and thus heating the endless belt to the desorption temperature.Infrared radiation is suitable for selectively exciting carbon dioxide, thus providing a particularly energy-efficient way to release the carbon dioxide bound in the endless belt in the desorption chamber.

[0018] In a particularly preferred embodiment of the invention, the heating means in the desorption chamber comprise a hot fluid bath with which the endless belt and / or the sorbent can be heated to a temperature of at least 90°C. A temperature of 95°C - 110°C represents a good compromise with regard to the removal of carbon dioxide from the sorbent and the necessary energy consumption. Furthermore, the risk of thermal decomposition and degradation of the sorbent is kept low in this temperature range. Immersing the endless belt in a hot fluid bath with a temperature of at least 90°C enables the necessary partial pressure to release the carbon dioxide bound in the sorbent.Since the solubility of carbon dioxide in a liquid, especially in water, decreases with increasing liquid temperature, the carbon dioxide dissolves from the sorption material of the endless belt and is not absorbed by the liquid but released in the desorption chamber. Furthermore, the liquid protects the sorption material from absorbing oxygen at the desorption temperature, so that the sorption material is not damaged and essentially retains its full absorption capacity for storing carbon dioxide. As an alternative to a liquid, the endless belt in the desorption chamber can also be heated to the desorption temperature by a gas or vapor, especially water vapor. Gases or vapors that can be easily separated from the carbon dioxide due to their condensation temperature and / or density are preferred.Water vapor is a preferred vapor because, as an inert gas, it does not react with carbon dioxide and can be easily separated from the carbon dioxide-water vapor mixture in a subsequent condensation step, leaving concentrated carbon dioxide.

[0019] In an advantageous embodiment of the system, a cooling liquid is filled into the cooling chamber, with the endless belt being guided through the cooling liquid to cool the sorbent. The cooling liquid should be such that preferably no cooling liquid or only small amounts of cooling liquid penetrate the sorbent to avoid impairing its ability to absorb carbon dioxide. A cooling liquid can dissipate a correspondingly high amount of heat from the endless belt, enabling rapid cooling of the endless belt and the sorbent material over a short distance.

[0020] It is particularly preferred if a liquid wiper for removing the cooling liquid from the endless belt is arranged on or in a through-opening connecting the cooling chamber to the adsorption chamber. This prevents the cooling liquid from being transported out of the cooling chamber. Furthermore, the moisture in the endless belt can be reduced, thereby promoting the reabsorption of carbon dioxide in the adsorption chamber.

[0021] In an advantageous embodiment of the system, a conveying element, in particular a fan, is arranged in or on the adsorption chamber to convey an air flow through the adsorption chamber. To ensure a uniform gas flow of ambient air through the adsorption chamber, it is helpful to arrange a conveying element on or in the adsorption chamber to generate such a gas flow. This allows the absorption of carbon dioxide in the adsorption chamber regardless of the wind conditions at the site of the system.

[0022] According to an advantageous embodiment of the system, a plurality of deflection elements are arranged in the adsorption chamber, wherein the endless belt is guided in a meandering manner through the adsorption chamber by the deflection elements. This allows the endless belt to be guided through the adsorption chamber over a correspondingly large length, whereby the absorption of a larger amount of carbon dioxide is possible, preferably up to the saturation of the absorption capacity of the sorbent. This enables particularly efficient separation of carbon dioxide from the ambient air. The orientation of the deflection elements can be dependent on the endless bath used in the system. In the case of an endless belt with a gas-permeable carrier material, it is particularly advantageous if the gas stream flows through the adsorption chamber several times through the endless belt.In the case of an endless belt which comprises a gas-tight carrier material coated with a sorption material, it is advantageous if the gas flow is guided parallel to the endless belt over as long a distance as possible along the endless belt. Alternatively, a gas-permeable carrier material can also be used for the endless belt. The ambient air can flow through the porous carrier structure and is bound in the sorption material of the endless belt. Alternatively, a combination is also possible in which a partial flow of the ambient air flows through a porous carrier structure of the endless belt and a second partial flow flows along the endless belt. Furthermore, it is possible for the endless belt to be gas-tight in sections, particularly in the edge sections, to increase its mechanical strength and gas-permeable in the central region, so that a combination of flow along and flow through the endless belt is also possible.

[0023] In a preferred embodiment of the system, means for supplying a carbon dioxide atmosphere to the desorption chamber are arranged at the desorption chamber. A carbon dioxide atmosphere in the desorption chamber allows a particularly high carbon dioxide concentration to be achieved in a gas stream discharged from the desorption chamber. Furthermore, the carbon dioxide atmosphere protects the sorption material from absorbing oxygen and, consequently, from a decrease in its sorption capacity during the next cycle of the endless belt.

[0024] To remove the desorbed carbon dioxide, it is advantageous if an outlet for removing a carbon dioxide-containing gas stream is provided on the desorption chamber. A carbon dioxide-containing gas stream in this context is understood to mean a gas stream with a carbon dioxide concentration of at least 15%, preferably of at least 35%. This allows the carbon dioxide separated during the process to be specifically fed to a storage facility or a process, in particular to a process for producing a synthetic fuel in which carbon dioxide is used as a starting material. Lower concentrations of carbon dioxide are particularly possible and useful if water vapor is used to expel carbon dioxide from the sorption material, and this water vapor is removed again from the expelled gas stream by condensation in a subsequent process step.

[0025] It is particularly preferred if a water separator for separating water, in particular water vapor, from the carbon dioxide-containing gas stream is arranged at the outlet or downstream of the outlet. In order to generate a carbon dioxide gas stream with the highest possible concentration, it can be helpful to flood the desorption chamber with an inert gas such as water vapor. Furthermore, the ambient air contains a certain amount of humidity, which must be removed from the separated carbon dioxide in order to produce the purest possible carbon dioxide gas. To separate the humidity from the gas stream, it is therefore advantageous to arrange a water separator at the outlet or downstream of the outlet to reduce the humidity of the carbon dioxide gas.

[0026] In a preferred embodiment of the system, the endless belt is designed as a continuous bag filled with a sorbent. This allows a larger amount of sorbent material to be easily introduced into the endless belt. The continuous bag is made of a gas-permeable material, which facilitates the absorption of carbon dioxide from the ambient air into the sorbent material and improves gas passage through the continuous bag.

[0027] Alternatively, it is advantageously provided that the endless belt is designed as a functional fabric or a functionalized film in which a sorbent is bound. This allows for the production of a particularly durable endless belt that has sufficient absorption capacity for the sorbent. Alternatively, the endless belt can also be designed as a fleece, net, gauze, or filter material in which a sorbent is bound. The functional fabric or the functionalized film is permeable to an air flow in order to easily bind carbon dioxide from the ambient air in the absorption chamber.

[0028] In an alternative embodiment, the endless belt comprises a carrier film coated with a functional layer for carbon dioxide sorption. This allows for the production of a particularly stable endless belt that can withstand even higher tensile forces when passing through the system. Furthermore, the carrier material can be designed to provide corrosion protection and prevent rusting upon contact with the heating fluid or cooling liquid. The sorbent of the coating can be designed to enable particularly efficient absorption and / or release of carbon dioxide.

[0029] It is particularly preferred if a washcoat is applied between the carrier film and the functional layer. A washcoat can facilitate the application of the functional layer or even make it possible in the first place. Furthermore, a washcoat increases the surface area of ​​the functional layer, which can improve the absorption of carbon dioxide in the functional layer of the sorbent. Furthermore, the bond between the functional layer and the carrier film can be increased to prevent flaking of the functional layer and increase the service life of the endless belt.

[0030] A further aspect of the invention relates to a process for separating carbon dioxide from the ambient air using such a system. Carbon dioxide from the ambient air is bound in the sorbent of the endless belt in the adsorption chamber, and the endless belt is heated in the desorption chamber to a temperature of at least 90°C, preferably from 95°C to 110°C, whereby the carbon dioxide bound in the sorbent is released from the endless belt. The endless belt is then cooled in the cooling chamber, whereby the endless belt is cooled to a temperature of less than 50°C, preferably to a temperature of less than 35°C, in order to enable renewed absorption of carbon dioxide into the sorbent of the endless belt.

[0031] The process according to the invention enables a comparatively simple and cost-effective separation of carbon dioxide from the ambient air. In particular, the continuous circulation of the endless belt ensures that the absorption, desorption, and cooling of the endless belt as a carrier of the sorbent occur simultaneously in corresponding sections of the endless belt, thus avoiding the constant heating, evacuation, and cooling of a sorption chamber. Rather, ideal conditions for the adsorption and subsequent desorption of carbon dioxide can be set in the adsorption chamber and the desorption chamber, respectively. Furthermore, the energy requirement can be drastically reduced compared to known solutions, since not the entire sorption chamber needs to be heated and cooled, but only the endless belt and the sorbent.The cooling chamber enables rapid cooling of the endless belt after desorption of the carbon dioxide, so that a corresponding section of the endless belt can be cooled over a short distance to a temperature which subsequently enables optimal adsorption of carbon dioxide.

[0032] In an advantageous embodiment of the method, the temperature in the desorption chamber is kept constant within a range of 90°C to 110°C. This means that the desorption chamber only needs to be heated once, so that energy consumption can be kept comparatively low and the atmosphere in the desorption chamber always has a temperature above the desorption temperature of carbon dioxide from the sorption material. Alternatively or additionally, it is advantageously provided that the endless belt or the sorbent bound in the endless bath is heated by electromagnetic radiation. Electromagnetic radiation can be used to specifically introduce energy into the endless belt in order to heat the sorbent to a desorption temperature of at least 90°C.It is not necessary to heat the entire desorption chamber to the desorption temperature, but it is sufficient if the endless belt and the sorbent in active contact with the endless belt are heated locally to the desorption temperature.

[0033] The electromagnetic radiation used to heat the endless belt and / or the sorbent can be microwave radiation. Alternatively, the electromagnetic radiation used to heat the endless belt and / or the sorbent can be infrared radiation.

[0034] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0035] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show:

[0036] Figure 1 shows a preferred embodiment of a system according to the invention for

[0037] Separation of carbon dioxide from the ambient air,

[0038] Figure 2 shows a further preferred embodiment of an inventive

[0039] Plant for the separation of carbon dioxide from the ambient air,

[0040] Figure 3 shows an embodiment of an endless belt for such a system,

[0041] Figure 4 shows another embodiment of an endless belt for such a system,

[0042] Figure 5 shows another embodiment of an endless belt for such a system,

[0043] Figure 6 is a schematic representation of the structure of a preferred

[0044] Embodiment of such an endless belt,

[0045] Figure 7 shows a further embodiment of such an endless belt, Figure 8 shows an alternative embodiment of an endless belt for such

[0046] facility, and

[0047] Figure 9 is a flow chart for carrying out a method according to the invention for separating carbon dioxide from the ambient air.

[0048] Figure 1 shows a preferred embodiment of a system according to the invention for separating carbon dioxide from the ambient air 10. The system 10 comprises an adsorption chamber 12 for binding carbon dioxide from the ambient air in a sorbent 80, a desorption chamber 14 for releasing the carbon dioxide bound in the sorbent 80, and a cooling chamber 16 for cooling the sorbent 80 after the release of the carbon dioxide bound in the sorbent 80. The system further comprises an endless belt 20, which surrounds or carries the sorbent 80, and a drive element 84, which is configured to move the endless belt 20 through the adsorption chamber 12, the desorption chamber 14, and the cooling chamber in this order.

[0049] The adsorption chamber 12 has a first inlet opening 34, through which an air stream 38 of ambient air with a carbon dioxide content of 400-500 ppm enters the adsorption chamber 12. Alternatively, ambient air with an increased carbon dioxide concentration can also enter the adsorption chamber 12. The absorption chamber 12 further has a first outlet opening 36, through which the air stream 38 exits the adsorption chamber 12. Furthermore, a conveying element 18, in particular a fan, is arranged on or in the adsorption chamber 12 to convey the gas flow through the adsorption chamber.A plurality of deflection elements 22 are arranged in the adsorption chamber 12, which guide the endless belt 20 in a meandering manner through the adsorption chamber 12 in order to guide the endless belt 20 over the longest possible path through the adsorption chamber 12 and thus enable the most extensive absorption of carbon dioxide from the ambient air in the sorbent 80. In addition, additional support elements, in particular support rollers, can be arranged in the adsorption chamber 12 between the deflection elements 22 in order to support the endless belt 20 and improve the guidance of the endless belt 20 through the adsorption chamber 12. The adsorption chamber 12 further has a second inlet opening 40 through which the endless belt 20 enters the adsorption chamber 12. Furthermore, the adsorption chamber 12 has a second outlet opening 42 through which the endless belt 20 is guided out of the adsorption chamber 12.At a first through-opening 44, which connects the adsorption chamber 12 to the desorption chamber 14, a sealing element 24 is arranged in order to minimize gas exchange between the adsorption chamber 12 and the desorption chamber 14.

[0050] The desorption chamber 14 comprises a trough 88 in which a hot fluid bath 26 is stored. The desorption chamber 14, and in particular the trough 88 for receiving the fluid bath 26, can be heated via heating means 82 in order to achieve a desorption temperature of at least 90°C in at least some sections of the desorption chamber 14. The desorption chamber 14 has an outlet 50 through which a carbon dioxide-rich gas stream is discharged from the desorption chamber 14 and fed to a storage device (not shown) or a process in which the carbon dioxide serves as a starting material. A water separator 86 can be arranged at the outlet 50 or downstream of the outlet 50 to separate water vapor from the carbon dioxide-rich gas stream. The desorption chamber 14 is under a carbon dioxide atmosphere 52.The aim is to maintain a constant temperature in the desorption chamber 14 between 90°C and 120°C, preferably between 95°C and 105°C, in order to avoid constant heating and cooling of the desorption chamber 14 and thus minimize energy consumption. The endless belt 20 is immersed in the fluid bath 26, whereby the sorbent 80 reaches a temperature and partial pressure at which the carbon dioxide bound in the sorbent 80 releases from the sorbent 80 and rises from the fluid bath 26 into the atmosphere of the desorption chamber 14. Via further deflection elements 22, the endless belt 20 is guided from the desorption chamber 14 into the cooling chamber 16 at a second through-opening 46 in a partition wall 58.

[0051] In the cooling chamber 16, the endless belt 20 is immersed in a cooling liquid 28, for example, water 30, to dissipate the heat from the endless belt 20 and cool the sorbent 80. A fluid separator 32 is arranged at a third through-opening 48, which connects the cooling chamber 16 to the adsorption chamber 12, to strip the cooling liquid 28 from the endless belt 20 and reduce the moisture of the sorbent 80 before the endless belt 20 with the sorbent 80 is returned to the adsorption chamber 12. Water 30 is ideal as a cooling liquid when the sorbent 80 itself absorbs no water 30 or only a small amount of water 30, or when its carbon dioxide storage capacity is only slightly restricted despite absorbing water. Alternatively, a different cooling liquid can be used that does not restrict, or only slightly restricts, the absorption of carbon dioxide by the sorbent 80.The system 10 further comprises a control unit 90 with a memory unit 92 and a computing unit 94. A machine-readable program code 96 is stored in the memory unit 92, which, when executed by the computing unit 94, controls or regulates the system for separating carbon dioxide from the ambient air.

[0052] Figure 2 shows a further preferred embodiment of a system 10 according to the invention for separating carbon dioxide from the ambient air. The system 10 comprises an adsorption chamber 12 for binding carbon dioxide from the ambient air in a sorbent 80, a desorption chamber 14 for releasing the carbon dioxide bound in the sorbent 80, and a cooling chamber 16 for cooling the sorbent 80 after the carbon dioxide bound in the sorbent 80 has been released. The system further comprises an endless belt 20, which surrounds or carries the sorbent 80, and a drive element 84, which is configured to move the endless belt 20 through the adsorption chamber 12, the desorption chamber 14, and the cooling chamber in this order.

[0053] The adsorption chamber 12 has a first inlet opening 34, through which an air stream 38 from ambient air with a carbon dioxide content of 400-500 ppm enters the adsorption chamber 12. The absorption chamber 12 further has a first outlet opening 36, through which the air stream 38 exits the adsorption chamber 12. Furthermore, a conveying element 18, in particular a fan, is arranged on or in the adsorption chamber 12 to convey the gas flow through the adsorption chamber. A plurality of deflection elements 22 are arranged in the adsorption chamber 12, which guide the endless belt 20 in a meandering manner through the adsorption chamber 12 in order to guide the endless belt 20 over the longest possible path through the adsorption chamber 12 and thus enable the most extensive absorption of carbon dioxide from the ambient air in the sorbent 80.The adsorption chamber 12 further has a second inlet opening 40 through which the endless belt 20 enters the adsorption chamber 12. Furthermore, the adsorption chamber 12 has a second outlet opening 42 through which the endless belt 20 is guided out of the adsorption chamber 12. A sealing element 24 is arranged at a first through-opening 44, which connects the adsorption chamber 12 to the desorption chamber 14, in order to minimize gas exchange between the adsorption chamber 12 and the desorption chamber 14. In order to release the carbon dioxide bound in the sorbent 80 in the desorption chamber 14, heating means 82 in the form of an infrared emitter 54 and / or a microwave emitter 56 are arranged in the desorption chamber 14, with which the endless belt 20 can be heated at least in sections above a desorption temperature.Carbon dioxide dissolves from the sorbent 80 and can be discharged via an outlet 50 and fed to a storage device (not shown) or a process in which the carbon dioxide serves as a starting material. The desorption chamber 14 is under a carbon dioxide atmosphere 52.

[0054] Furthermore, means for reducing the pressure in the desorption chamber 14, in particular a vacuum pump, can be arranged at the desorption chamber 14 in order to reduce the partial pressure in the desorption chamber 14 and promote the release of carbon dioxide from the sorbent 80. Via further deflection elements 22, the endless belt 20 is guided from the desorption chamber 14 into the cooling chamber 16 at a second through-opening 46 in a partition wall 58.

[0055] In the cooling chamber 16, the endless belt 20 is immersed in a cooling liquid 28, in particular water 30, to dissipate the heat from the endless belt 20 and cool the sorbent 80. A fluid separator 32 is arranged at a third through-opening 48, which connects the cooling chamber 16 to the adsorption chamber 12, to strip the cooling liquid 28 from the endless belt 20 and reduce the moisture in the sorbent 80 before the endless belt 20, together with the sorbent 80, is returned to the adsorption chamber 12. Alternatively, the endless belt 20 can also be cooled by blowing a cold gas stream into the cooling chamber 16, thereby eliminating the need for a cooling circuit with a cooling liquid 28 and allowing the endless belt 20 to be fed to the adsorption chamber 12 essentially dry.

[0056] The system 10 further comprises a control unit 90 with a memory unit 92 and a computing unit 94. A machine-readable program code 96 is stored in the memory unit 92, which, when executed by the computing unit 94, controls or regulates the system for separating carbon dioxide from the ambient air.

[0057] Figure 3 shows an exemplary embodiment of an endless belt 20 for such a system 10. In this exemplary embodiment, the endless belt 20 is designed as an endless bag 64 filled with a sorption material 80. The endless bag 64 has a gas-permeable structure through which a gas stream can pass, allowing the carbon dioxide to be bound in the adsorption chamber 12 and released from the sorption material 80 in the desorption chamber 14.

[0058] Figure 4 shows a further exemplary embodiment of an endless belt 20 for such a system 10. In this exemplary embodiment, the endless belt 20 is designed as a functionalized fabric 60, which comprises the sorption material 80 and has a gas-permeable structure through which a gas stream can pass and the carbon dioxide can be bound accordingly in the adsorption chamber 12 and released accordingly from the sorption agent 80 in the desorption chamber 14.

[0059] Figure 5 shows a further exemplary embodiment of an endless belt 20 for such a system 10. In this exemplary embodiment, the endless belt 20 is designed as a functionalized film 62 to which a sorption material 80 adheres. The functionalized film 62 can be gas-permeable or, as shown in Figure 5, essentially gas-impermeable. In this case, the carbon dioxide from the ambient air is bound when an air stream passes along a surface of the functionalized film 62. In this embodiment, the desorption of the carbon dioxide in the desorption chamber 14 also occurs by increasing the temperature and, if necessary, simultaneously reducing the partial pressure.Alternatively, in the case of a gas-permeable film 62, the sorbent can also be arranged between different layers of the film 62, through which a gas stream can pass and the carbon dioxide can be bound accordingly in the adsorption chamber 12 and released accordingly from the sorbent 80 in the desorption chamber 14.

[0060] Figure 6 shows a schematic representation of the structure of a preferred embodiment of such an endless belt 20. The endless belt 20 is designed as a gauze, fleece 66, net 68, or similar fabric 72 made of a gas-permeable material, with the sorbent 80 stored between the layers of the endless belt 20.

[0061] Figure 7 shows a further schematic representation of the structure of a preferred embodiment of such an endless belt 20. The endless belt 20 is designed as a filter medium 70 and can have several pockets in which the sorption material 80 is stored.

[0062] Figure 8 shows an alternative embodiment of an endless belt 20 for such a system 10. The endless belt 20 comprises a preferably gas-impermeable, tear-resistant carrier film 74, which is coated with a washcoat 76 and a functional layer 78, wherein the functional layer 78 comprises a sorbent 80. The coating can increase the surface area of ​​the endless belt 20 in order to optimize the adsorption or subsequent desorption of carbon dioxide. In this embodiment, the carbon dioxide is bound in the absorption chamber 12 when the air stream comes into contact with a reactive surface of the functional layer 78. The desorption of the carbon dioxide in the desorption chamber 14 also occurs in this embodiment by increasing the temperature and, if necessary, simultaneously reducing the partial pressure.

[0063] Figure 9 shows a flow diagram for carrying out a method according to the invention for separating carbon dioxide from the ambient air using such a system 10. In one process step <100> The endless belt 20 is pulled through the adsorption chamber 12 by the drive element 84, and carbon dioxide from the ambient air is bound in the sorbent 80 in a section of the endless belt 20. In a subsequent process step <110> the corresponding section of the endless belt 20 is pulled into the desorption chamber 14 and heated to a temperature of at least 90°C, whereby the carbon dioxide bound in the sorbent 80 is released from the endless belt 20.In one process step <120> the endless belt 20 is pulled into the cooling chamber 16 for cooling, wherein the corresponding section of the endless belt 20 is cooled to a temperature of less than 50°C, preferably to a temperature of 0°C to 30°C, in order to enable a renewed absorption of carbon dioxide into the sorbent 80 of the endless belt 20.

[0064] List of reference symbols

[0065] Attachment

[0066] Adsorption chamber

[0067] Desorption chamber cooling chamber

[0068] Conveying element

[0069] endless belt

[0070] deflection element

[0071] Sealing element hot fluid bath

[0072] coolant

[0073] Water

[0074] Fluid separator first inlet opening first outlet opening air flow second inlet opening second outlet opening first through opening second through opening third through opening

[0075] Outlet

[0076] Carbon dioxide atmosphere

[0077] Infrared emitter

[0078] Microwave emitter

[0079] Partition - I8 functional fabric functionalized film endless bag fleece net

[0080] Filter material fabric carrier film washcoat functional layer

[0081] Sorbent Heating medium Drive element Water separator Tank

[0082] Control unit Storage unit Computing unit Program code

Claims

Patent claims System (10) for separating carbon dioxide from the ambient air, comprising: an adsorption chamber (12) for binding carbon dioxide from the ambient air in a sorbent (80), a desorption chamber (14) for releasing the carbon dioxide bound in the sorbent (80), wherein heating means (82) for heating the sorbent (80) are arranged in the desorption chamber (14), a cooling chamber (16) for cooling the sorbent (80) after the release of the carbon dioxide bound in the sorbent (80), an endless belt (20) which comprises or carries the sorbent (80), and a drive element (84) which is designed to move the endless belt (20) through the adsorption chamber (12), the desorption chamber (14) and the cooling chamber (16).System (10) according to claim 1, characterized in that the heating means (82) in the desorption chamber (14) comprise an infrared emitter (54) and / or a microwave emitter (56). System (10) according to claim 1 or 2, characterized in that the heating means (82) in the desorption chamber (14) comprise a hot fluid bath (26) with a temperature of at least 90°C. System (10) according to one of claims 1 to 3, characterized in that a cooling liquid (28) is filled into the cooling chamber (16), wherein the endless belt (20) is guided through the cooling liquid (28) to cool the sorbent. Plant (10) according to claim 4, characterized in that a fluid separator (32) for stripping the cooling liquid (28) from the endless belt (20) is arranged on or in a through opening (48) which connects the cooling chamber (16) to the adsorption chamber (12). System (10) according to one of claims 1 to 5, characterized in that a conveying element (18) for conveying an air flow through the adsorption chamber (12) is arranged in or on the adsorption chamber (12). System (10) according to one of claims 1 to 6, characterized in that a plurality of deflection elements (22) are arranged in the adsorption chamber (12), wherein the endless belt (20) is guided in a meandering manner through the adsorption chamber (12) by the deflection elements (22). System (10) according to one of claims 1 to 7, characterized in that the desorption chamber (14) is supplied with a carbon dioxide atmosphere. Plant (10) according to one of claims 1 to 8, characterized in that an outlet (50) for discharging a carbon dioxide-containing gas stream with a carbon dioxide concentration of at least 25% is formed on the desorption chamber (14).System (10) according to claim 9, characterized in that a water separator (86) for separating water from the carbon dioxide-containing gas stream is arranged at the outlet (50) or downstream of the outlet (50). System (10) according to one of claims 1 to 10, characterized in that the endless belt (20) is designed as an endless bag (64), functional fabric (60), functionalized film (62), filter material (70), nonwoven fabric (66), or net (68), wherein the sorption material (80) is bound in the endless belt (20). System according to one of claims 1 to 10, characterized in that the endless belt (20) comprises a carrier film (74) coated with a functional layer (78) for sorbing carbon dioxide. Method for separating carbon dioxide from the ambient air with a plant (10) according to one of claims 1 to 12, wherein. Carbon dioxide from the ambient air is bound in the adsorption chamber (12) in the sorbent (80) of the endless belt (20), the endless belt (20) is heated in the desorption chamber (14) to a temperature of at least 90°C, whereby the carbon dioxide bound in the sorbent (80) is released from the endless belt (20), and Cooling the endless belt (20) in the cooling chamber (16), wherein the endless belt (20) is cooled to a temperature of less than 50°C to enable renewed absorption of carbon dioxide into the sorbent (80) of the endless belt (20). A method for separating carbon dioxide from the ambient air according to claim 13, wherein the temperature in the desorption chamber (14) is maintained in a range from 90°C to 110°C. A method for separating carbon dioxide from the ambient air according to claim 13 or 14, wherein the sorbent (80) in the endless belt (20) and / or the sorbent bound in the endless belt is heated by electromagnetic radiation.

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