Installation and method for separating carbon dioxide from ambient air

Abstract

The invention relates to an installation (10) for separating carbon dioxide from ambient air. The installation (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). Heating means for heating the sorbent (80) are arranged in the desorption chamber (14). The installation (10) also comprises a continuous belt (20), which comprises or supports the sorbent (80), and a drive element (84), which is designed to move the continuous belt (20) through the adsorption chamber (12), the desorption chamber (14), and the cooling chamber (16). According to the invention, air guiding elements (110) are arranged in the adsorption chamber (12), said air guiding elements elongating a flow path through the adsorption chamber (12). The invention additionally relates to a method for separating carbon dioxide from 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 cycling. 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] In addition, plants are known from the state of the art in which the absorption and subsequent desorption of carbon dioxide takes place in a continuous process, with the sorption / desorption taking place through a sorption belt.

[0010] US 2022 / 0212 141 A1 describes a device for separating carbon dioxide from ambient air. The device comprises a housing defining a first zone, a second zone, a third zone, and a fourth zone. The device comprises an inlet, a first outlet, a second outlet, and a conveyor belt. The inlet is configured to receive a carbon dioxide-containing fluid in the first zone. The first outlet is configured to discharge a carbon dioxide-depleted fluid from the first zone. The second outlet is configured to discharge a carbon dioxide-rich fluid from the third zone. The conveyor belt runs through each of the zones. The conveyor belt contains a carbon dioxide sorbent.In the first zone, the carbon dioxide sorbent is configured to adsorb carbon dioxide from the carbon dioxide-containing fluid to produce the carbon dioxide-depleted fluid. In the third zone, the carbon dioxide sorbent is configured to desorb the captured carbon dioxide.

[0011] DE 102020 128 989 A1 discloses a process for the continuous recovery of carbon dioxide from a carbon dioxide-containing atmosphere. A fibrous carrier material loaded with polyethyleneimine is alternately passed through at least one adsorption zone and at least one desorption zone, with the carrier material binding carbon dioxide from the atmosphere in the adsorption zone and releasing it again in the desorption zone. DE 102020 128 989 A1 further discloses a plant for separating carbon dioxide from the atmosphere, wherein the plant comprises an adsorption zone, a desorption zone, and a belt material that is continuously circulated through the adsorption zone and the desorption zone of the plant.

[0012] Furthermore, WO 2019 / 165151 A1 discloses a system and method for the passive collection of atmospheric carbon dioxide. The system comprises a collection chamber with a first opening and a sorbent regeneration system. The system includes a collecting body connected to and movable through a support structure.The capture body contains a sorbent material and is movable by the support structure to be in a collection configuration in which at least a portion of the capture body is in contact with a natural airflow outside the desorption chamber so that atmospheric carbon dioxide is captured by the sorbent material, and in a release configuration in which at least a portion of the capture body containing the captured carbon dioxide is in contact with a natural airflow outside the desorption chamber so that the atmospheric carbon dioxide is captured by the sorbent material.

[0013] The invention is based on the object of reducing the energy requirement in a continuously operating plant for separating carbon dioxide from the ambient air, increasing the yield of carbon dioxide and at least partially overcoming the disadvantages known from the prior art.

[0014] The object is achieved by a system for separating carbon dioxide from the ambient air, which system 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 carbon dioxide bound in the sorbent has been released. The system further comprises an endless belt that surrounds or carries the sorbent and a drive element that is designed to move the endless belt through the adsorption chamber, the desorption chamber, and the cooling chamber. According to the invention, air guiding elements are arranged in the adsorption chamber, which extend a flow path through the adsorption chamber.

[0015] 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 the 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 that subsequently enables optimal adsorption of carbon dioxide. By extending the flow path, the endless belt and the air flow through the adsorption chamber remain in contact for as long as possible, enabling particularly efficient removal of carbon dioxide from the ambient air. Furthermore, the longer residence time of the ambient air in the adsorption chamber compared to known solutions improves the removal efficiency with regard to the carbon dioxide contained in the ambient air, thereby increasing the carbon dioxide yield.The features listed in the dependent claims enable advantageous improvements and further developments of the plant for separating carbon dioxide from the ambient air mentioned in the independent claim.

[0016] In a preferred embodiment of the invention, an ambient air stream is guided substantially parallel to the endless belt. This allows the flow path through the adsorption chamber to be multiplied compared to an air stream perpendicular to the endless belt, thereby increasing the carbon dioxide removal rate and improving the efficiency of the carbon dioxide removal process.

[0017] It is preferred if the air guide elements comprise a first wall and a second wall running substantially parallel to the first wall. Furthermore, the air guide elements comprise first air guide plates running substantially perpendicular to the first wall and second air guide plates running substantially perpendicular to the second wall. The walls and the air guide plates form flow channels in the adsorption chamber, which extend the flow path through the adsorption chamber and thus increase the adsorption rate of carbon dioxide from the ambient air. This allows the efficiency of the process for separating the carbon dioxide to be further improved.

[0018] Particularly preferably, the first air guide plates are fixed to the first wall and the second air guide plates are fixed to the second wall. The first air guide plates and the second air guide plates form a meandering flow channel through the adsorption chamber. This creates a particularly long flow channel, which is at least five times, preferably at least ten times, longer than a known flow guide through the adsorption chamber. This significantly increases the residence time of the ambient air in the adsorption chamber, allowing more carbon dioxide to be separated from the ambient air under otherwise identical conditions. This increases the yield of separated carbon dioxide, so that more carbon dioxide can be separated with the same process time.

[0019] In a further preferred embodiment of the invention, deflection elements for an air flow guided through the adsorption chamber are formed on the walls and / or on the air guide plates. This reduces the flow resistance when flowing through the adsorption chamber, thereby reducing the drive power for the conveying element, in particular for the fan. Furthermore, dead zones in the corners of the flow channels, where vortices form, can be avoided. These vortices are not in contact with the endless belt and thus cannot increase the efficiency of the separation.

[0020] It is particularly preferred if the deflection elements are designed in the shape of a curve, in particular in the shape of a quarter circle or a semicircle, in order to guide the air flow in the region of a deflection element for the endless belt, following the endless belt. This enables a particularly favorable deflection of the ambient air flow.

[0021] According to an advantageous embodiment of the system, the endless belt has a projection in the axial direction of the deflection element relative to a deflection element for guiding and / or driving the endless belt, with a gap formed between the projection and a wall of the adsorption chamber. As a result, the endless belt, as an additional flow element, can prevent flow through the adsorption chamber transversely to the deflection elements. This allows for particularly efficient air flow with a particularly low air leakage.

[0022] In an advantageous embodiment of the system, the endless belt and / or a shaft of a deflection element is guided in a guide rail that is guided along a wall defining the adsorption chamber. This allows for additional sealing of the gap between the endless belt and / or the deflection elements and the walls of the adsorption chamber, thereby achieving a particularly low air leakage and guiding the air flow essentially completely through the flow channels of the adsorption chamber.

[0023] It is particularly preferred if a brush seal is arranged between the guide rail and the shaft and / or between the guide rail and the endless belt. Leakage can be further reduced by one or more brush seals, so that an air flow deviating from the flow path predetermined by the air guide elements is essentially prevented. This makes it possible to achieve a particularly long residence time of the ambient air in the adsorption chamber and, associated with this, a particularly efficient separation of carbon dioxide from the ambient air. According to the invention, a conveying element, in particular a fan, for conveying an air flow through the adsorption chamber is arranged in or on the adsorption chamber.To ensure a consistent flow of ambient air through the adsorption chamber, it is helpful to have a conveying element located on or within the adsorption chamber to generate such a flow. This allows the absorption of carbon dioxide in the adsorption chamber regardless of the wind conditions at the plant site. A blower is a particularly simple and cost-effective conveying device for generating a consistent air flow, which is passed through the adsorption chamber at a moderate speed to adapt the residence time of the ambient air to the adsorption capacity of the sorbent on or in the endless belt.

[0024] In an advantageous embodiment of the system, the endless belt is connected to a deflection element in a force-locking and / or form-locking manner, wherein the deflection element is driven by a drive element, in particular an electric drive motor. This allows for a particularly simple and cost-effective drive of the endless belt. Since the desorption chamber and the cooling chamber can be filled with liquid, driving a deflection element in the adsorption chamber is particularly advantageous, as additional sealing effort is eliminated.

[0025] In a preferred embodiment of the system, a plurality of deflection elements are arranged in the adsorption chamber, with the endless belt being guided in a meandering fashion 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, enabling the absorption of a larger amount of carbon dioxide, preferably up to the saturation of the absorption capacity of the sorbent. This enables particularly efficient removal of carbon dioxide from the ambient air. The orientation of the deflection elements can be determined depending on the endless belt used in the system.In the case of an endless belt which comprises a gas-tight carrier material which is coated with a sorption material, it is advantageous if the gas flow is guided parallel to the endless belt over as long a path as possible, so that the most efficient adsorption of the carbon dioxide can be achieved.

[0026] In an advantageous embodiment of the system, the endless belt comprises a carrier film, in particular a gas-impermeable carrier film, which is coated with a functional layer for the sorption of carbon dioxide. This allows the production of a particularly stable endless belt that can withstand even higher tensile forces as it passes through the system. Furthermore, the carrier material can be designed in such a way that it provides corrosion protection and does not begin to rust upon contact with the heating fluid or cooling liquid. The sorbent of the coating can be designed in such a way that it enables particularly efficient absorption and / or release of carbon dioxide.In addition, a gas-impermeable carrier material can prevent gas from passing through the endless belt, whereby the endless belt can be used as an additional air guiding element to guide the air flow of the ambient air in a meandering manner through the adsorption chamber.

[0027] In a preferred embodiment of the system, 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 heat the endless belt locally and the sorbent in active contact with the endless belt to the desorption temperature.

[0028] 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 for the endless belt and the sorbent in active contact with the endless belt to be heated 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.

[0029] In a particularly preferred embodiment of the system, 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.

[0030] 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.

[0031] 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.A further aspect of the invention relates to a method for separating carbon dioxide using a plant for separating carbon dioxide as described in the preceding sections, which comprises at least the following method steps: conveying an air stream of ambient air with a conveying element through a first inlet opening into the adsorption chamber, wherein the air stream is guided through the air guiding elements as it flows through the adsorption chamber in order to lengthen the flow path through the adsorption chamber, wherein the carbon dioxide from the ambient air is bound in the adsorption chamber in the sorbent of the endless belt, heating the endless belt in the desorption chamber, wherein the carbon dioxide bound in the sorbent is released from the endless belt, and cooling the endless belt in the cooling chamber in order to enable renewed absorption of carbon dioxide in the sorbent of the endless belt.

[0032] 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 carbon dioxide desorption, allowing a corresponding section of the endless belt to be cooled over a short distance to a temperature that subsequently enables optimal adsorption of carbon dioxide. The air guiding elements allow particularly favorable flow conditions to be set in the adsorption chamber, which promote the adsorption of carbon dioxide in the sorbent of the endless belt. In particular, the airflow to the endless belt can be improved and the residence time of the air stream in the adsorption chamber can be extended, thereby increasing the efficiency of adsorbing carbon dioxide from the ambient air.In an advantageous embodiment of the method, the air flow is guided through the adsorption chamber essentially parallel to the endless belt, and gas passage through the endless belt is essentially avoided. This allows for a particularly long residence time of the ambient air in the adsorption chamber and, associated with this, particularly efficient adsorption of carbon dioxide.

[0033] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0034] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show:

[0035] Figure 1 shows a preferred embodiment of a system according to the invention for

[0036] Separation of carbon dioxide from the ambient air,

[0037] Figure 2 shows a further preferred embodiment of an inventive

[0038] Plant for the separation of carbon dioxide from the ambient air,

[0039] Figure 3 shows a further preferred embodiment of an inventive

[0040] Plant for the separation of carbon dioxide from the ambient air,

[0041] Figure 4 shows a further preferred embodiment of an inventive

[0042] Plant for the separation of carbon dioxide from the ambient air,

[0043] Figure 5 shows an embodiment of an endless belt for such a system,

[0044] Figure 6 shows another embodiment of an endless belt for such a system,

[0045] Figure 7 shows another embodiment of an endless belt for such a system,

[0046] Figure 8 shows an alternative embodiment of an endless belt for such a

[0047] facility, and

[0048] Figure 9 shows a flow diagram for carrying out a method according to the invention for separating carbon dioxide from the ambient air. 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 carbon dioxide bound in the sorbent 80 has been released. The system 10 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 16 in this order.

[0049] The adsorption chamber 12 has a first inlet opening 34, through which an air stream 38 from the 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 air stream 38 or a gas stream through the adsorption chamber 12.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 through the adsorption chamber 12 over the longest possible distance and thus to enable the most extensive absorption of carbon dioxide from the ambient air in the sorption agent 80.

[0050] Furthermore, a first wall 102 and a second wall 104 are arranged in the adsorption chamber 12, which define a flow path through the absorption chamber 12. Air guiding elements 100 in the form of first air baffles 106 are arranged on the first wall 102 and extend horizontally and parallel to the endless belt 20 into the adsorption chamber. Further air guiding elements 100 in the form of second air baffles 108 are arranged on the second wall 104, which also extend horizontally and parallel to the endless belt 20. In addition, further air guiding elements 100, in particular deflection elements 110 for guiding the air flow 38, can be arranged in the adsorption chamber 12 in order to reduce the flow resistance as it flows through the adsorption chamber 12.The first air baffles 106 and the second air baffles 108 form a meander that extends the flow path through the adsorption chamber 12 from the first inlet opening 34 to the first outlet opening 36. The air flow 38 essentially follows the endless belt 20 and flows essentially parallel to the endless belt 20 through the adsorption chamber 12. The first wall 102 and the second wall 104 can be the boundary walls of the adsorption chamber 12 or additional walls arranged within the adsorption chamber 12.

[0051] Figure 1 shows a variant embodiment of the adsorption chamber 12 in which the endless belt 20 runs essentially horizontally and is deflected by 180° at each deflection element 22. Alternatively, however, it is also conceivable for the endless belt 20 to run essentially vertically. In this embodiment, the walls 102 and 104 are part of a ceiling wall and a floor wall of the adsorption chamber 12 or run parallel to such a ceiling wall and floor wall. In this exemplary embodiment, the air baffles 106, 108 run essentially vertically and parallel to the endless belt 20 in order to achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0052] 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.

[0053] 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 the desorption chamber 14, at least in sections. 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.

[0054] 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 content 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.

[0055] 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.

[0056] Figure 2 shows a further embodiment of a system 10 according to the invention for separating carbon dioxide from the ambient air. The sectional plane is rotated by 90° compared to the illustration in Figure 1. The system 10 for separating carbon dioxide from the ambient air 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 10 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 16 in this order.

[0057] The endless belt 20 is deflected by deflection elements 22 in the form of deflection rollers 70, so that the endless belt is guided essentially horizontally through the absorption chamber 12 at various levels. The endless belt 20 has a projection relative to the deflection elements 22, so that the endless belt prevents vertical flow through the adsorption chamber 12 except for a narrow gap 68. The deflection elements 22 are designed as deflection rollers 70 and are mounted in a rotationally fixed manner in the housing of the adsorption chamber 12 via shafts 112. The deflection rollers 70 are driven by the drive element 84, in particular an electric motor connected to one of the deflection rollers via the shaft 112. The shafts 112 are guided in a guide rail 114, which prevents the air flow 38 from flowing vertically past the deflection rollers 70.Brush seals 66 can be provided in the guide rails 114 to further reduce vertical air leakage at the shaft 112. In combination with the projection of the endless belt 20, this ensures that the air flow essentially follows the path of the endless belt 20, thus achieving the longest possible flow path through the adsorption chamber 12 in order to achieve the most efficient adsorption of carbon dioxide in the sorbent 80 of the endless belt 20. Additionally, as shown in Figure 1, air guide elements 100, 102, 104, 106, 108, 110 can be provided in the adsorption chamber 12 to guide the air flow 38 and achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0058] Figure 2 shows a variant embodiment of the adsorption chamber 12 in which the endless belt 20 runs essentially horizontally and is deflected by 180° at each deflection element 22. Alternatively, however, it is also conceivable for the endless belt 20 to run essentially vertically. In this embodiment, the shafts 112 and the guide rail are mounted in a ceiling wall and a floor wall of the adsorption chamber 12. Additionally, as shown in Figure 1, air guide elements 100, 102, 104, 106, 108, 110 can be provided in the adsorption chamber 12 to guide the air flow 38 and achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0059] Figure 3 shows a further embodiment of a system 10 according to the invention for separating carbon dioxide from the ambient air. The sectional plane is rotated by 90° compared to the illustration in Figure 1. The system 10 for separating carbon dioxide from the ambient air 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 10 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 16 in this order.

[0060] The endless belt 20 is deflected by deflection elements 22 in the form of deflection rollers 70, so that the endless belt is guided essentially horizontally through the absorption chamber 12 at various levels. In this exemplary embodiment, in contrast to the exemplary embodiment shown in Figure 2, the endless belt 20 does not project beyond the deflection elements 22. A gap 68 remains between the deflection elements 22 and the walls of the adsorption chamber 12. The deflection elements 22 are designed as deflection rollers 70 and are mounted in a rotationally fixed manner in the housing of the adsorption chamber 12 via shafts 112. The deflection rollers 70 are driven by the drive element 84, in particular an electric motor connected to one of the deflection rollers via the shaft 112. The shafts 112 are guided in a guide rail 114, which prevents the air flow 38 from flowing vertically past the deflection rollers 70.Since the seal across the endless belt 20 is omitted, the guide rails 114 in this exemplary embodiment preferably extend across the entire width of the adsorption chamber 12 in order to largely prevent the air flow 38 from flowing vertically past the gap 68. Brush seals 66 can be provided in the guide rails 114 to further reduce a leakage air flow in the vertical direction at the shaft 112. This ensures that the air flow essentially follows the course of the endless belt 20, thus achieving the longest possible flow path through the adsorption chamber 12 in order to achieve the most efficient adsorption of carbon dioxide in the sorbent 80 of the endless belt 20.In addition, as shown in Figure 1, air guide elements 100, 102, 104, 106, 108, 110 can be provided in the adsorption chamber 12 in order to guide the air flow 38 and to achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0061] Figure 3 shows a variant embodiment of the adsorption chamber 12 in which the endless belt 20 runs essentially horizontally and is deflected by 180° at each deflection element 22. Alternatively, however, it is also conceivable for the endless belt 20 to run essentially vertically. In this embodiment, the shafts 112 and the guide rail are mounted in a ceiling wall and a floor wall of the adsorption chamber 12. Additionally, as shown in Figure 1, air guide elements 100, 102, 104, 106, 108, 110 can be provided in the adsorption chamber 12 to guide the air flow 38 and achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0062] Figure 4 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 16 in this order.

[0063] 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. Furthermore, a first wall 102 and a second wall 104 are arranged in the adsorption chamber 12, which define a flow path through the absorption chamber 12. Air guide elements 100 in the form of first air baffles 106 are arranged on the first wall 102, which extend horizontally and parallel to the endless belt 20 into the adsorption chamber 12.On the second wall 104, further air guide elements 100 in the form of second air baffles 108 are arranged, which also extend horizontally and parallel to the endless belt 20. In addition, further air guide elements 100 in the form of deflection elements 110 for guiding the air flow 38 are arranged in the adsorption chamber 12 in order to reduce the flow resistance as it flows through the adsorption chamber 12 and, in particular, to avoid eddies in the corners of the air guide channels formed by the air baffles 106, 108 and walls 102, 104. The first air baffles 106 and the second air baffles 108 form a meander, which extends the flow path through the adsorption chamber 12 from the first inlet opening 34 to the first outlet opening 36. The air flow 38 essentially follows the endless belt 20 and flows essentially parallel to the endless belt 20 through the adsorption chamber 12.The first wall 102 and the second wall 104 may be the boundary walls of the adsorption chamber 12 or additional walls arranged within the adsorption chamber 12.

[0064] Figure 4 shows a variant embodiment of the adsorption chamber 12 in which the endless belt 20 runs essentially horizontally and is deflected by 180° at each deflection element 22. Alternatively, however, it is also conceivable for the endless belt 20 to run essentially vertically. In this embodiment, the walls 102 and 104 are part of a ceiling wall and a floor wall of the adsorption chamber 12 or run parallel to such a ceiling wall and floor wall. In this exemplary embodiment, the air baffles 106, 108 run essentially vertically and parallel to the endless belt 20 in order to achieve a corresponding extension of the flow path through the adsorption chamber 12.

[0065] 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 to a process in which the carbon dioxide serves as the starting material. The desorption chamber 14 is under a carbon dioxide atmosphere 52. Alternatively, the desorption of the carbon dioxide can also be carried out using a desorption chamber 14 with a fluid bath 26, as described in Figure 1.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Figure 5 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.

[0070] Figure 6 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, the carbon dioxide can be bound accordingly in the adsorption chamber 12 and released accordingly from the sorption material 80 in the desorption chamber 14.

[0071] Figure 7 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 appropriate, 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.

[0072] 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.

[0073] 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 <200> An air flow 38 of the ambient air is sucked in by means of a conveying element 18, in particular by means of a fan, and introduced into an adsorption chamber 12 through a first inlet opening 34. The air flow 38 is guided through the adsorption chamber 12 along a flow path defined by the air guiding elements. The flow path is delimited by a first wall 102 and a second wall 104, as well as first air baffles 106 arranged on the first wall 102 and second air baffles 108 attached to the second wall 104, so that the air flow 38 is guided in a meandering manner along the endless belt 20.The endless belt 20 is in a parallel process step <210> by the drive element 84 through the adsorption chamber 12 and thereby binds carbon dioxide from the ambient air in the sorbent 80 in a section of the endless belt 20. In a subsequent process step <220> the corresponding section of the endless belt 20 is drawn into the desorption chamber 14 and heated to a temperature of at least 90°C, preferably to at least 100°C, whereby the carbon dioxide bound in the sorbent 80 is released from the endless belt 20. In a process step <230> 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.

[0074] List of reference symbols

[0075] Attachment

[0076] Adsorption chamber

[0077] Desorption chamber

[0078] Cooling chamber

[0079] Conveying element

[0080] endless belt

[0081] deflection element

[0082] Sealing element hot fluid bath

[0083] coolant

[0084] Water

[0085] Fluid separator first inlet opening first outlet opening

[0086] Air flow second inlet opening second outlet opening first through opening second through opening third through opening

[0087] Outlet

[0088] Carbon dioxide atmosphere

[0089] Infrared emitter

[0090] Microwave emitter

[0091] Partition wall functionalized fabric functionalized film

[0092] Endless bags

[0093] Brush seal

[0094] gap

[0095] pulley

[0096] Overhang

[0097] Carrier film

[0098] Wash coat

[0099] Functional layer

[0100] Sorbents

[0101] Heating medium

[0102] drive element

[0103] Water separator

[0104] tub

[0105] control unit

[0106] storage unit

[0107] Computing unit

[0108] Program code

[0109] Rounding

[0110] Air guide element first wall second wall first air baffle second air baffle

[0111] Deflection element of the air duct

[0112] Wave

[0113] Guide rail first process step second process step 220 third process step

[0114] 230 fourth procedural step

Claims

Patent claims 1. A system (10) for separating carbon dioxide from the ambient air, comprising: an adsorption chamber (12) for binding carbon 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), wherein a first inlet opening (34) is provided on the adsorption chamber (12). designed to allow an air stream to enter the adsorption chamber (12),and wherein a conveying element (18) for conveying an air flow (38) through the adsorption chamber (12) is arranged in or on the adsorption chamber (12), characterized in that air guiding elements (100) are arranged in the adsorption chamber (12), which extend a flow path through the adsorption chamber (12).

2. System (10) according to claim 1, wherein an air flow (38) of the ambient air is guided substantially parallel to the endless belt (20).

3. System (10) according to claim 1 or 2, wherein the air guide elements (100) have a first wall (102) and a second wall (104) running substantially parallel to the first wall (102), as well as first air guide plates (106) running substantially perpendicular to the first wall (102) and second air guide plates (108) running substantially perpendicular to the second wall (104).

4. System (10) according to claim 3, wherein the first air baffles (106) are fixed to the first wall (102) and the second air baffles (108) are fixed to the second wall (104), such that that the first air baffles (106) and the second air baffles (108) form a meandering flow channel through the adsorption chamber (12).

5. System (10) according to claim 2 or 3, wherein deflection elements (110) for an air flow (38) guided through the adsorption chamber (12) are formed on the walls (102, 104) and / or on the air baffles (106, 108).

6. System (10) according to claim 5, wherein the deflection elements (110) are designed in the form of a curve (98) in order to guide the air flow (38) in the region of a deflection element (22) for the endless belt (20) following the endless belt (20).

7. Plant (10) according to one of claims 1 to 6, wherein the endless belt (20) has a projection (72) in the axial direction of the deflection element (22) relative to a deflection element (22) for guiding and / or driving the endless belt (20), wherein a gap (68) is formed between the projection (72) and a wall (102, 104) of the adsorption chamber (12).

8. System (10) according to one of claims 1 to 7, wherein the endless belt (20) and / or a shaft (112) of a deflection element (22) is guided in a guide rail (114) which is guided on a wall (102, 104) that delimits the adsorption chamber (12).

9. System (10) according to claim 8, wherein a brush seal (66) is arranged between the guide rail (114) and the shaft (112) and / or the endless belt (20).

10. System (10) according to one of claims 1 to 9, wherein the endless belt (20) is non-positively and / or positively connected to a deflection element (22), wherein the deflection element (22) is driven by a drive element (84).

11. Plant (10) according to one of claims 1 to 10, wherein 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).

12. Plant according to one of claims 1 to 11, wherein the endless belt (20) comprises a carrier film (74) coated with a functional layer (78) for the sorption of carbon dioxide.

13. A method for separating carbon dioxide from the ambient air with a system (10) according to one of claims 1 to 12, wherein an air stream (38) is conveyed from the ambient air by a conveying element (18) through a first inlet opening (34) into the adsorption chamber (12), wherein the air stream (38) is guided through the air guiding elements (100) as it flows through the adsorption chamber (12) in order to lengthen the flow path through the adsorption chamber (12), wherein the carbon dioxide from the ambient air in the adsorption chamber (12) is bound in the sorbent (80) of the endless belt (20), the endless belt (20) is heated in the desorption chamber (14), wherein the carbon dioxide bound in the sorbent (80) is released from the endless belt (20), and the endless belt (20) is cooled in the cooling chamber (16) is cooled to enable renewed absorption of carbon dioxide in the sorbent (80) of the endless belt (20).

14. A method for separating carbon dioxide from the ambient air according to claim 13, wherein the air flow (38) is guided through the adsorption chamber (12) substantially parallel to the endless belt (20) and gas passage through the endless belt (20) is substantially avoided.

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