A combination of a rotatable pre-drying unit and CO2 recovery.

Abstract

A device for recovering carbon dioxide from a gaseous medium, comprising: a first air passage for the gaseous medium; a second air passage for the discharge air of the device; and at least one rotatable pre-drying unit containing at least one adsorbent for physically adsorbing water. The present invention relates to an apparatus comprising at least one rotatable pre-drying unit that is rotatable around an axis, and a first air passage directed radially toward the at least one rotatable pre-drying unit. Furthermore, methods and apparatus for recovering carbon dioxide and the use of the methods are disclosed.

Description

Technical Field

[0005] ,

[0004] , ,

[0001] The present invention relates to an apparatus for recovering carbon dioxide from a gaseous medium, a method for recovering carbon dioxide from a gaseous medium, and the use of an apparatus and a method for recovering carbon dioxide.

Background Art

[0002] [[ID= twelfth]]The emission of carbon dioxide into the atmosphere is currently regarded as the main cause of climate change. Carbon capture and storage technology (CCS) is an efficient and effective method for reducing carbon dioxide emissions into the atmosphere.

[0003] Known methods for capturing carbon dioxide are absorption, adsorption, membrane-based systems, electrochemical separation, and cryogenic separation.

[0004] A technical application for capturing carbon dioxide is the direct air capture method (DAC). Carbon dioxide is removed from the surrounding air by a separator. Thereby, pure carbon dioxide can be obtained, and this carbon dioxide can be reused in another process.

[0005] International Publications 2016 / 005226, 2015 / 185434, and 2014 / 170184 describe exemplary methods for recovering carbon dioxide using chemiosorbents by a temperature-vacuum swing process. Amine-based chemiosorbents are prone to performance degradation and deterioration when the material combines with oxygen at temperatures higher than approximately 60°C. This performance degradation and deterioration can occur during the desorption phase at 100°C unless measures are taken, for example, to replace the inert atmosphere in the system with water vapor or another gas. These protective measures are laborious and expensive. It is desirable that vapor be introduced during desorption to displace residual oxygen, thereby preventing material damage due to degradation. By exposing the adsorbent material to air, the adsorbent material is cooled to approximately 50°C before the system transitions back to the adsorption phase (i.e., CO2 absorption) after the completion of the desorption phase.

[0006] This means an additional process step that reduces the system's time and energy efficiency.

[0007] Physical adsorbents typically have a greater affinity for water than for CO2. For this reason, these systems should be equipped with a pre-drying device to dry the air. This pre-drying is structurally and energy-intensive.

[0008] International Publication No. 2022 / 109746 describes a method for capturing carbon dioxide using physicoads in polar (low temperature, dry) zones, in which these materials preferably absorb water from the surrounding air.

[0009] When using physical adsorbents, there is an incentive to limit the use of such systems to the Earth's polar regions. This is because, based on the lower temperatures, the air in polar regions contains less water than in temperate, subtropical, or tropical climate zones. Nevertheless, technical pre-drying cannot be completely omitted because it is not certain that dew point temperatures of, for example, -40°C or -60°C will be consistently present throughout the year. Furthermore, the effort required to install and operate equipment in polar regions is enormous compared to the Earth's developed areas.

[0010] "Knox et al., 'Investigation of Desiccants and CO2Sorbents for Exploration Systems,' 2016-2017, ICES-2017-188" discloses the use of physicoads to separate CO2 from cabin air in spacecraft and space stations. Here, the so-called "Four Bed Molecular Sieve (4BMS)" approach is found. This approach specifies the connection of modules that pre-dry the cabin air and separate CO2.

[0011] European Patent Application Publication No. 1142623 discloses a temperature vacuum swing process for isolating carbon dioxide from a wet, hot gas mixture.

[0012] U.S. Patent Application Publication No. 2010251887 describes a method for isolating carbon dioxide from a gaseous mixture, including a temperature swing adsorption step.

[0013] International Publication No. 2014 / 012966 discloses an apparatus for adsorption-desorption swing reactions. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] International Publication No. 2016 / 005226 [Patent Document 2] International Publication No. 2015 / 185434 [Patent Document 3] International Publication No. 2014 / 170184 [Patent Document 4] International Publication No. 2022 / 109746 [Patent Document 5] European Patent Application Publication No. 1142623 [Patent Document 6] U.S. Patent Application Publication No. 2010251887 [Patent Document 7] International Publication No. 2014 / 012966 [Non-patent literature]

[0015] [Non-Patent Document 1] Knox et al., “Investigation of Desiccants and CO2 Sorbents for Exploration Systems”, 2016-2017, ICES-2017-188 [Overview of the project] [Problems that the invention aims to solve]

[0016] The object of the present invention is to improve an apparatus for recovering carbon dioxide from a gaseous medium and a method for recovering carbon dioxide from a gaseous medium, thereby overcoming the above-mentioned drawbacks, at least partially. [Means for solving the problem]

[0017] This problem is solved by the apparatus according to claim 1, the method according to claim 8, and the use according to claim 10.

[0018] Another advantageous configuration of the present invention will become apparent from the dependent claims and the following description of preferred embodiments of the present invention.

[0019] The apparatus according to the present invention for recovering carbon dioxide from a gaseous medium is - a first air flow path for a gaseous medium, - a second air flow path for the exhaust air of the device, - at least one rotatable pre-drying unit containing at least one adsorbent that physically adsorbs water and comprising at least one rotatable pre-drying unit is rotatably drivable about an axis, and the first air flow path is directed radially towards at least one pre-drying unit.

[0020] The gaseous medium may be air, ambient air, for example exhaust gas from an industrial plant, a gas mixture, a point source, etc. The gaseous medium contains, inter alia, carbon dioxide (CO2). In a preferred embodiment, the gaseous medium is ambient air, also referred to herein as air.

[0021] [[ID=十七]]The device according to the invention has a first air flow path for a gaseous medium. The gaseous medium supplied to the first air flow path may be process air.

[0022] The device according to the invention further has a second air flow path for the exhaust air of the device. The exhaust air is preferably a moist gaseous medium from which carbon dioxide has been removed.

[0023] Furthermore, the device according to the invention has at least one rotatable pre-drying unit containing at least one adsorbent that physically adsorbs water, and at least one rotatable pre-drying unit is rotatably drivable about an axis, and the first air flow path is directed radially towards at least one rotatable pre-drying unit.

[0024] Rotatable in the context of the present invention means that the pre-drying unit can rotate about its own axis and is preferably configured to rotate about its own axis during operation.

[0025] The rotatable pre-drying unit is preferably an adsorption wheel or an adsorption heat exchanger. The adsorption wheel is a wheel-shaped component with an adsorbent coated on its outer surface. The adsorption wheel or adsorption heat exchanger can rotate and can be fed with a gaseous medium, from which specific substances can be adsorbed by the adsorbent on the rotatable pre-drying unit.

[0026] The apparatus according to the present invention may include a rotatable pre-drying unit. Alternatively, the apparatus according to this invention may include at least two rotatable pre-drying units. If at least two rotatable pre-drying units are present, these pre-drying units may be arranged in parallel and / or in series.

[0027] At least one rotatable pre-drying unit is rotatably driven around its axis; that is, at least one rotatable pre-drying unit rotates about its own axis. The first air passage is directed radially towards at least one rotatable pre-drying unit. Thus, the direction of flow of the gaseous medium extends radially.

[0028] The adsorbent that physically adsorbs water is preferably placed on the circumferential surface of a rotatable pre-drying unit, so that the first air passage is directed directly to the adsorbent and the gaseous medium flowing through the first air passage comes into direct contact with the adsorbent.

[0029] As the rotatable pre-drying unit rotates, a portion of the rotatable pre-drying unit comes into contact with the gaseous medium, and the adsorbent provided on this portion of the rotatable pre-drying unit can at least partially absorb moisture, i.e., water, from the gaseous medium. Further rotation causes the rotatable pre-drying unit to move, and the moisture-soaked portion of the adsorbent can move further towards a predetermined area, i.e., the regeneration side. In this area, the adsorbent can be dried. The adsorbent can be dried by supplying so-called regeneration air. Continued rotation allows the dried adsorbent to be reused to dry the gaseous medium. Thus, the pre-dried gaseous medium can flow out of the rotatable pre-drying unit.

[0030] The flow direction of process air and regenerated air extends particularly in the radial direction.

[0031] The portion of the rotatable pre-drying unit that comes into contact with the gaseous medium may be up to 50% of the circumferential surface of the rotatable pre-drying unit, preferably up to 30% of the circumferential surface of the rotatable pre-drying unit, and more preferably up to 25% of the circumferential surface of the rotatable pre-drying unit.

[0032] This arrangement in the direction of flow is advantageous because relatively high moisture pressure exists in the radial region outside the circumferential surface on the drying side, which allows for good adsorption of moisture, i.e., water, from the gaseous medium when the flow velocity is relatively low. As the radius decreases, the moisture pressure decreases due to the progression of water adsorption. At the same time, the flow velocity is increased, which supports the dynamics of adsorption, thereby enabling good drying even at relatively low moisture pressures.

[0033] The apparatus according to the present invention may have at least one pre-conditioning unit. The pre-conditioning unit is a component that can supply a gaseous medium in a suitable form to one or more other components, such as at least one rotatable pre-drying unit. The pre-conditioning unit can, for example, cool or heat the gaseous medium to a defined temperature. The pre-conditioning unit can compress or expand the gaseous medium using pressure, either in addition to or as an alternative to temperature control.

[0034] By using a pre-adjustment unit, the apparatus according to the present invention can also be used for a variety of different climatic conditions (e.g., higher H2O content when temperature and / or air humidity are higher).

[0035] In one embodiment, the apparatus according to the present invention includes at least one drying unit and at least one CO2 unit.

[0036] In a drying unit, a pre-dried gaseous medium can be dried to a specified moisture content. Preferably, the drying unit has at least one suitable material that can adjust the moisture content. This material may be uniformly distributed within the drying unit. Alternatively, the material may be distributed in layers within the drying unit. In particular, if the drying unit has a layered structure, the drying unit may have a drying gradient. That is, a first layer can bring about a first drying to a specified moisture content. Another layer of the drying unit can bring about another drying to a specified moisture content. The drying unit may optionally have a number of layers. Ideally, these layers are aligned vertically with each other.

[0037] The drying unit adsorbs preferably 99.0% (corresponding to a dew point of -40°C downstream of the drying unit), more preferably 99.7% (a dew point of -50°C), and even more preferably 99.9% (a dew point of -60°C) of the amount of H2O present in the gaseous medium.

[0038] The drying unit may have at least four modules, at least one of which is a desorption module, at least two of which are heat transfer modules, and at least one of which is an adsorption module. Each module of the drying unit may be made of a different material suitable for drying. Preferably, all modules of the drying unit are identically made of one or more suitable materials.

[0039] The number of modules in the drying unit may be multiple times the number of individual modules as described above.

[0040] A desorption module is understood to be a structural unit that can desorb and, preferably, adsorb a substance. Here, the substance may be H2O. After desorption, the desorption module can be used, for example, as an adsorption module and / or a heat transfer module.

[0041] An adsorption module is understood to be a structural unit that can adsorb and, preferably, desorb a substance. Here, the substance may be H2O. After adsorption, the adsorption module can be used, for example, as a desorption module and / or as a heat transfer module.

[0042] A heat transfer module is understood to be a structural unit capable of releasing or absorbing heat. Depending on the stage of the process the heat transfer module is in, the module can either release or absorb heat. In the heat transfer stage before the desorption stage, the module can absorb heat (from another module that is releasing heat in the heat transfer stage). For example, the heat transfer module may be a previous adsorption module. The adsorption of a substance in the adsorption module may simultaneously cause heat accumulation, i.e., a rise in temperature in the adsorption module. The heat is preferably released and can ideally be used in another module, for example, by allowing the adsorbed substance to be desorbed using the supplied heat. Heat transfer can be carried out, for example, by circulating air.

[0043] The drying unit may have at least four modules. In alternative embodiments, the drying unit may have more than four modules. The number of modules is preferably adjusted so that there is a constant mass flow rate through the apparatus.

[0044] The number of heat transfer modules in a drying unit may correspond to the total number of desorption modules and adsorption modules in the drying unit. For example, the number of modules can be expressed as follows: Number of drying modules = x desorption modules + y adsorption modules + z heat transfer modules Here, z = 2, or an integer multiple of 2.

[0045] Two drying modules may be in the process of heat transfer, in which case one module sends heat and the other receives heat.

[0046] The drying unit may be configured independently of the CO2 unit.

[0047] The apparatus according to the present invention may further have at least one CO2 unit. The CO2 unit is capable of adsorbing a specified amount of carbon dioxide. Preferably, the CO2 unit has at least one material capable of adsorbing carbon dioxide.

[0048] The CO2 unit adsorbs preferably 80%, more preferably 90%, and even more preferably 99% of the amount of carbon dioxide present in the gaseous medium.

[0049] The CO2 unit may include at least one adsorption module and at least one desorption module. The CO2 unit may have one module that can alternately function as either an adsorption module or a desorption module. Preferably, the CO2 unit may be configured to either adsorb CO2 or desorb CO2 depending on the state of the method.

[0050] The CO2 unit may further have at least one heat transfer module.

[0051] Preferably, the CO2 unit module may be configured to adsorb CO2 or desorb CO2 and transfer heat, depending on the state of the method.

[0052] The apparatus contains a specified number of drying unit modules and a specified number of CO2 unit modules. These modules can be operated independently of each other during the main operating phases, "adsorption" and "desorption." This allows for the individual optimization of the drying unit and CO2 unit operations. This system is also referred to as a "separated system." The air mass flow through the apparatus is preferably constant, so that the exact number of drying unit modules required for CO2 adsorption in the CO2 unit modules are operated during the adsorption phase, thereby achieving the necessary dew point-temperature conditions at the CO2 unit inlet.

[0053] In one embodiment, the second air passage is directed radially towards a rotatable pre-drying unit. In such an embodiment, the first and second air passages extend parallel to each other. Thus, the exhaust air supplied to the rotatable pre-drying unit through the second air passage can receive moisture, i.e., water, and dry the adsorbent.

[0054] The rotatable pre-drying unit may have one type of adsorbent that physically adsorbs water.

[0055] In one embodiment, the rotatable pre-drying unit may include at least two adsorbents that physically adsorb moisture.

[0056] At least one adsorbent that physically adsorbs water may be selected from the group consisting of zeolite, graphite, aluminosilicate, MOF (metal-organic frame), or silica gel.

[0057] Preferably, at least one adsorbent is silica gel. Alternatively, at least one adsorbent is zeolite.

[0058] If at least two types of adsorbents are present, these adsorbents may be a combination of silica gel and zeolite. The combination of adsorbents may be arranged in layers. Preferably, the first adsorbent can be used to perform rough drying of the gaseous medium, and the second adsorbent can be used to perform final drying of the gaseous medium.

[0059] Even when air guides are arranged radially, the specified coating patterns may be usable. In the outer radial region, an adsorbent for rough drying (e.g., silica gel) is advantageous, while in the inner radial region, an adsorbent for final drying (e.g., zeolite) is advantageous.

[0060] A combination consisting of at least two adsorbents, i.e., at least two coatings on the rotatable pre-drying unit, is advantageous because it allows the gaseous medium to be dried to an even lower dew point compared to a rotatable pre-drying unit having only one type of adsorbent coating. The ratio between the first and second coatings is preferably 70% / 30% to 90% / 10%, and more preferably 75% / 25% to 80% / 20%.

[0061] The apparatus according to the present invention may further include at least one intercooler.

[0062] Preferably, the intercooler is located downstream of the drying unit. The intercooler may be located upstream of the CO2 unit. In one possible variation, the intercooler is located between the drying unit and the CO2 unit.

[0063] The intercooler cools the incoming (gasic) medium to a defined temperature, preferably below 15°C, more preferably below 10°C, and even more preferably below 6°C. Particularly preferably, the incoming (gasic) medium is cooled to a temperature of 5°C.

[0064] Additional and / or larger air conditioning equipment can be used to further cool the drying unit to even lower temperatures (e.g., -20 to -40°C) downstream of the drying unit.

[0065] The apparatus according to the present invention may have at least one heat exchanger unit. The heat exchanger unit can function particularly for heat recovery. By using the heat exchanger unit, the energy demand supplied by an external energy source can be reduced, thereby increasing the energy efficiency of the apparatus.

[0066] The heat recovered by the heat exchanger unit can be used, for example, for the desorption of H2O from the drying unit and / or carbon dioxide from the CO2 unit.

[0067] The energy demand of the apparatus according to the present invention can be further reduced by the use of at least one heat pump. The heat pump can provide energy for desorption in the drying unit and / or CO2 unit. The cold exhaust air from the heat pump can be used for cooling, for example, in a rotatable pre-drying unit and / or intercooler.

[0068] The apparatus according to the present invention may further include at least one blower. The blower can act to guide a gaseous medium through the apparatus. The blower may be located on the inlet side and / or outlet side of the apparatus. If the blower is located on the inlet side, the gaseous medium is pushed into the apparatus (e.g., into a rotating drying unit). If the blower is located on the outlet side of the apparatus, the gaseous medium is drawn through the apparatus by the suction action generated by the blower.

[0069] There may be multiple blowers, or there may be just one blower.

[0070] For the simplest possible structure, attempts are made to omit multiple blowers and, if possible, use variable throttles to generate airflow distribution, thereby compensating for any additional pressure loss.

[0071] At least one drying unit and / or at least one CO2 unit may similarly contain at least one physicoadsorbent or at least one adsorbent. A physicoadsorbent is a compound that can bind substances (e.g., gases such as carbon dioxide) to itself by physical force. Ideally, a physicoadsorbent desorbs the adsorbed substance under controlled conditions. This desorption can occur, for example, through the action of heat, pressure, or the accumulation of another substance, while releasing the initially adsorbed substance.

[0072] The physical adsorbents used are preferably robust, resistant to performance degradation, and commercially available on a large scale. Compared to chemical adsorbents, they typically do not exhibit performance degradation or degradation phenomena within the temperature range in which they are used.

[0073] The physical adsorbent may be a homogeneous substance or a mixture. Preferably, at least one of the physical adsorbents is solid. The at least one physical adsorbent may be selected from the group consisting of silica gel, zeolite, aluminosilicate, and MOF (metal-organic framework).

[0074] Preferably, the drying unit has a layered structure of physical adsorbents. In one embodiment, the drying unit has at least one layer of silica gel and at least one layer of zeolite. The at least one layer of silica gel is preferably located in the inlet area of ​​the drying unit so that the silica gel can perform initial drying. The thus dried medium is then guided through at least one zeolite layer so that the medium can be further dried.

[0075] Alternatively, the drying unit may include at least one layer of silica gel and at least two layers of zeolite. A layer of zeolite, a so-called protective layer, may be placed in the inlet area of ​​the drying unit. The protective layer can work to remove contaminants from the gaseous medium, thereby protecting the subsequent steps. Following the protective layer, at least one layer of silica gel may be placed so that the silica gel can carry out the initial drying. The partially dried medium is then guided through at least one zeolite layer, which allows for further drying of the partially dried medium.

[0076] The ratio of the first layer (e.g., silica gel) to the second layer (e.g., zeolite) may be in the range of 1.5 to 3.5, preferably in the range of 2.0 to 3.0, and more preferably in the range of 2.3 to 2.5.

[0077] Ideally, one or more adsorbents in the rotatable pre-drying unit are matched to one or more physical adsorbents in the drying unit.

[0078] The apparatus according to the present invention can be operated at a CO2 partial pressure in the range of approximately 380 to 480 ppm, preferably in the range of 400 to 450 ppm, and particularly preferably in the range of 420 ppm. This results in different ratios of CO2 partial pressure and H2O partial pressure. For use under atmospheric conditions, an optimal configuration of the inlet height (Schuetthoehen) of the adsorption unit may be advantageous.

[0079] Preferably, drying is carried out such that the medium flowing out of the drying unit has a moisture content of 0.0196% to 0.007% (dew point -40°C), preferably 0.007% to 0.0022% (dew point -50°C), and more preferably 0.0022% to 0.0006% (dew point -60°C).

[0080] The CO2 unit may similarly have a layered or uniform structure of (one or more types of) physical adsorbents. Preferably, the CO2 unit has a uniform structure of (one or more types of) physical adsorbents. The physical adsorbent may be a zeolite. The physical adsorbent may be a mixture of at least two different types of zeolites.

[0081] The CO2 unit preferably comprises at least two modules. These modules may be identically configured or differently configured from one another. In a preferred embodiment, each module contains a zeolite as a physical adsorbent, and in particular, all modules are identically configured.

[0082] The pouring height or layer thickness within the drying unit and the CO2 unit may similarly have a specified ratio. This ratio may be in the range of 1.2 to 2.5, preferably in the range of 1.5 to 2.0, and more preferably in the range of 1.7 to 1.9. Particularly preferably, the ratio of the pouring height or layer thickness between the drying unit and the CO2 unit is 1.8.

[0083] Furthermore, the present invention relates to a method for recovering carbon dioxide, - The step of providing a gaseous medium to the first air passage, -A step of pre-drying a gaseous medium in a rotating pre-drying unit, -In at least one drying unit, the steps include drying a pre-dried gaseous medium, -In the CO2 unit, CO2 is adsorbed from a dried gaseous medium, and at the same time, CO2 is recovered in the CO2 unit by desorption. The present invention relates to a method having a rotating pre-drying unit that rotates around an axis, and a first air passage directed radially toward the rotating pre-drying unit.

[0084] Preferably, the method according to the present invention is carried out in the apparatus according to the present invention. The features of the apparatus can also be applied to the method accordingly.

[0085] One apparatus can be used to carry out the method according to the present invention. Alternatively, at least two apparatuses can be used. The apparatuses may be arranged in parallel.

[0086] As described above, the gaseous medium may be the atmosphere, ambient air, exhaust gas from an industrial plant, a gas mixture, a point source, etc. The gaseous medium contains carbon dioxide in particular. Preferably, the gaseous medium is ambient air, also referred to as air in this specification.

[0087] One step of the method according to the present invention is to pre-dry a gaseous medium supplied to a first air passage in a rotating pre-drying unit. In this case, the pre-drying unit, which rotates around an axis, is passed through the gaseous medium radially.

[0088] Pre-drying is preferably carried out until the moisture content of the gaseous medium is 0.5% by mass, more preferably 0.25% by mass, and even more preferably 0.1% by mass.

[0089] The rotating pre-drying unit may be an adsorption wheel or an adsorption heat exchanger. An adsorption wheel is a wheel-shaped component whose outer surface is coated with an adsorbent. The adsorption wheel or adsorption heat exchanger can rotate and be passed through a medium from which specific substances can be adsorbed using the adsorbent.

[0090] In one embodiment, a rotating pre-drying unit includes at least one adsorbent that adsorbs water. The adsorbent may be any of the adsorbents listed herein. There may be one adsorbent or a combination of at least two adsorbents.

[0091] In one embodiment, at least one adsorbent is a combination of two adsorbents. The two adsorbents may be a first layer made of silica gel and a second layer made of zeolite.

[0092] The method according to the present invention further includes the step of drying a pre-dried gaseous medium in a drying unit. The drying unit may include a plurality of modules, as described herein with respect to the apparatus.

[0093] The modules of the drying unit may be in various different operating states, in which H2O is adsorbed in at least one module of the drying unit, H2O is desorbed in at least one module of the drying unit, and heat is transferred in at least two modules of the drying unit.

[0094] The number of modules in each operating state of the drying unit may be multiple times the number of individual modules as described above.

[0095] The drying unit may have more than four modules. These modules may similarly be in operating states for adsorbing H2O, desorbing H2O, and transferring heat. The relationships between the individual operating states can be assigned to the individual modules as follows: Number of drying modules = x desorption modules + y adsorption modules + z heat transfer modules Here, z is either 2 or an integer multiple of 2.

[0096] Drying can be carried out with at least one suitable material, and the moisture content can be adjusted by this material or by these materials. The material can exist as a homogeneous material. Alternatively, the material can exist in layers. In particular, when the material exists in layers, a drying gradient can occur. That is, the first layer brings about a first drying to a specified moisture content. Another drying can be carried out in another layer to a specified moisture content. There may be multiple layers as needed. Ideally, these layers are coordinated with each other. One or more layers may be at least one type of physical adsorbent as described herein.

[0097] During drying, a suitable 99.0%, more preferably 99.7%, and even more preferably 99.9% of the amount of H2O present in the gaseous medium can be adsorbed.

[0098] Preferably, the gaseous medium is prepared before drying. This preparation is used, in particular, to supply the gaseous medium to the method with a uniform temperature and / or uniform pressure.

[0099] In one embodiment, the method according to the present invention includes cooling the gaseous medium before adsorption of CO2. Cooling of the gaseous medium can be carried out by an intercooler. Alternatively, another structural component for temperature control of the gaseous medium may be considered. This may be, for example, an air-water heat exchanger, an air-air heat exchanger, and / or an air-air-air heat exchanger.

[0100] The incoming gaseous medium is preferably cooled to a defined temperature. The temperature is preferably below 15°C, more preferably below 10°C, and even more preferably below 6°C. Preferably, the incoming gaseous medium is cooled to a temperature of 5°C.

[0101] The method according to the present invention may include the heat recovery step described above.

[0102] The energy demand of the method according to the present invention can be reduced as described above by using at least one heat pump.

[0103] In one embodiment, the method according to the present invention includes the step of transporting a gaseous medium means using a blower. The blower may correspond to the blower of the apparatus according to the present invention.

[0104] A blower can act to guide a gaseous medium through the device. The blower may be located on the inlet and / or outlet side of the device. If the blower is located on the inlet side, the gaseous medium is pushed into the device (e.g., into the pre-adjustment unit). If the blower is located on the outlet side of the device, the gaseous medium is drawn through the device by the suction action generated by the blower.

[0105] In the method according to the present invention, the desorption of adsorbed CO2 is preferably carried out by heating and under vacuum. The unit on which the CO2 is adsorbed is heated to a defined temperature. This heating allows the CO2 to separate from the unit and preferably be released in high purity.

[0106] In the method according to the present invention, preferably, at the same time, H2O is adsorbed in at least one module of the drying unit, while H2O is desorbed in at least one other module of the drying unit. If CO2 is desorbed in at least one module of the CO2 unit, preferably, at the same time, CO2 is adsorbed in at least one other module of the CO2 unit.

[0107] CO2 can be derived from the apparatus or method with a purity preferably higher than 80%, more preferably higher than 90%, and even more preferably higher than 95%. In some embodiments, CO2 is derived with a purity higher than 99%.

[0108] Desorption of adsorbed CO2 can be carried out by heating to a temperature higher than 50°C, particularly higher than 80°C, preferably higher than 100°C, more preferably higher than 120°C, and even more preferably higher than 140°C. Preferably, in the method according to the present invention, steam is not required for CO2 desorption. Preferably, CO2 desorption is carried out under vacuum at an absolute pressure of 10 millibars.

[0109] The method according to the present invention may further include a step of cooling the gaseous medium before CO2 adsorption. Cooling can be carried out using an intercooler, as described herein.

[0110] The method and apparatus according to the present invention can be used in direct air recovery (DAC) methods.

[0111] Furthermore, the present invention relates to the use of an apparatus or method according to the present invention for recovering carbon dioxide from a gaseous medium.

[0112] The recovered carbon dioxide can be used as a starting material for other compounds. For example, carbon dioxide can be used as a starting material for the manufacture of plastics, synthetic fuels (e-fuels), and the like.

[0113] Furthermore, the air drying equipment for the DAC facility is disclosed. Additionally, the DAC facility and a method for operating the DAC facility are described.

[0114] DAC (Direct Air Capture) systems are used to capture carbon dioxide from the surrounding air. DAC stands for "Direct Air Capture." In a known DAC system, the surrounding air flows through a carbon dioxide capture device, which then captures the carbon dioxide from the air. The captured carbon dioxide can then be used for a variety of purposes.

[0115] Carbon dioxide (CO2) capture devices in DAC (Digital Air Capture) systems, which work to capture carbon dioxide from the surrounding air, may be based on various different mechanisms of action. Therefore, CO2 capture devices in DAC systems based on physical adsorption, chemical adsorption, electrochemical separation principles, membrane separation methods, or cryogenic separation techniques are known from field experience. In particular, when a CO2 capture device in a DAC system is based on physical adsorption or cryogenic separation principles, that is, when a physical adsorbent (also called a molecular sieve) is used as the adsorbent, it is important that the surrounding air is dried beforehand. Therefore, DAC systems whose CO2 capture devices are based on the principle of physical adsorption have air drying devices that can dry the surrounding air before it is supplied to the CO2 capture device, and thus before carbon dioxide is captured.

[0116] Several different methods are known for drying ambient air. For example, water or water vapor can be extracted from ambient air by condensation by cooling it to a temperature below the dew point. Another air drying method utilizes the principle of physical adsorption, which allows for the removal of water from the air, at least partially, through physical adsorption, in order to dry the air.

[0117] In known DAC (Dry Air Conditioning) facilities, drying the ambient air is extremely energy-intensive. This is true even when air drying equipment that utilizes the principle of physical adsorption to remove at least partially water from the ambient air is used to dry the ambient air. Therefore, in known DAC facilities, a great deal of energy is required to regenerate the adsorbent used to physically adsorb water and to enable the desorption of the adsorbent.

[0118] The article “Investigation of Desiccants and CO2Sorbens for Exploration Systems 2016-2017, James C. Knox et al., 47th International Conference on Environmental Systems, July 16-20, 2017, Charleston, South Carolina, USA (ICES-2017-188)” describes equipment for at least partially removing carbon dioxide from air for use in spaceflight. In this equipment, the air from which carbon dioxide should be at least partially removed is first dried and then guided through a carbon dioxide capture device. Both the drying of the air and the separation of carbon dioxide from the air are based on the principle of physicoadsorption. In this case, the drying of the air is based on the use of a solid adsorption bed in the so-called temperature swing method, which is extremely energy-intensive.

[0119] Therefore, in order to operate DAC equipment, particularly the air drying equipment within DAC equipment, efficiently, there is a need to reduce the energy consumption required to dry the air in DAC equipment.

[0120] This serves as a starting point for describing a new type of air drying device for DAC equipment, a DAC equipment equipped with such an air drying device, and a method for operating such DAC equipment.

[0121] This problem is solved by the air drying device for the DAC equipment described in claim 1, the DAC equipment described in claim 6, and the method for operating the DAC equipment described in claim 10.

[0122] In the first configuration, this specification describes an air drying device for a DAC facility, the DAC facility is configured to recover carbon dioxide from the surrounding air, In the carbon dioxide recovery system of the DAC facility, a first air passage for ambient air that should be dried and for which carbon dioxide recovery is desirable, The second air passage for the exhaust air of the carbon dioxide capture device of the DAC facility, A rotating storage unit carrying an adsorbent that physically adsorbs water and Equipped with, The rotating storage body is rotatably driven such that, as it rotates, its segments are temporarily positioned within a first airflow channel and temporarily within a second airflow channel. This allows, when the segments are positioned within the first airflow channel, water to be absorbed from the surrounding air to be dried by the adsorbent of the rotating storage body, and when the segments are positioned within the second airflow channel, water to be released from the adsorbent of the rotating storage body into the exhaust air of the carbon dioxide recovery unit of the DAC facility.

[0123] The air drying apparatus for a DAC facility described herein has a first air passage for ambient air to be dried, from which carbon dioxide is to be recovered in the carbon dioxide recovery apparatus of the DAC facility.

[0124] The air drying apparatus for the DAC equipment described herein further comprises a second air passage for the exhaust air of the carbon dioxide recovery unit of the DAC equipment.

[0125] The air drying apparatus for a DAC facility described herein further comprises a rotating storage body carrying an adsorbent for physically adsorbing water, the rotating storage body is rotatably driven such that, as it rotates, a segment of the storage body is temporarily positioned in a first air passage and temporarily positioned in a second air passage, so that, when the segment is positioned in the first air passage, water can be absorbed from the surrounding air to be dried by the adsorbent of the rotating storage body, and when the segment is positioned in the second air passage, water can be released from the adsorbent of the rotating storage body into the exhaust air of the carbon dioxide recovery device of the DAC facility.

[0126] The air drying apparatus for a DAC (Digital Acquisition Control) system described herein enables particularly efficient drying of ambient air from which carbon dioxide is subsequently to be recovered. During air drying, only minimal energy is required, particularly for the regeneration of the used adsorbent, which absorbs water from the ambient air to be dried via physical adsorption. The energy required for the regeneration or desorption of the used adsorbent during air drying is substantially equal to the kinetic energy required to rotate the rotating storage container. With minimal energy consumption, ambient air from which carbon dioxide is subsequently to be recovered can be efficiently dried.

[0127] Another configuration of an air drying apparatus as described herein is: The first air passage and the second air passage extend parallel to each other, and air flows through them in opposite directions. The rotation axis of the storage unit extends parallel to the longitudinal axis of the air passages, which extends in the direction of flow through both air passages. It is characterized by the following:

[0128] Another configuration of an air drying apparatus as described herein is: Similarly, a third air passage is provided for the exhaust air of the carbon dioxide recovery device of the DAC facility, allowing the exhaust air of the carbon dioxide recovery device to move from the third air passage to the second air passage, and a heating device is provided to heat the exhaust air of the carbon dioxide recovery device of the DAC facility downstream of the third air passage and upstream of the second air passage, and the rotating storage body is rotatably driven so that, as it rotates, the segments of the storage body are temporarily positioned in the first air passage, temporarily in the second air passage, and temporarily in the third air passage, so that when the segments are positioned in the first air passage, water can be absorbed from the surrounding air to be dried by the adsorbent, when the segments are positioned in the second air passage, water can be released from the adsorbent into the heated exhaust air of the carbon dioxide recovery device of the DAC facility, and when the segments are positioned in the third air passage, the segments can be cooled via the exhaust air of the carbon dioxide recovery device of the DAC facility. It is characterized by the following:

[0129] Preferably, the carbon dioxide recovery unit for a DAC facility as described herein has a third air passage for the exhaust air of the carbon dioxide emission unit of the DAC facility. The exhaust air of the carbon dioxide recovery unit is transferable from the third air passage to the second air passage. Accordingly, the air drying unit as described herein has a heating unit to heat the exhaust air of the carbon dioxide recovery unit of the DAC facility downstream of the third air passage and upstream of the second air passage. The rotating storage unit is rotatable such that, as the storage unit rotates, the segments of the storage unit are temporarily positioned in the first air passage, temporarily in the second air passage, and temporarily in the third air passage, so that when the segments are positioned in the first air passage, water can be absorbed from the surrounding air to be dried by the adsorbent; when the segments are positioned in the second air passage, water can be released from the adsorbent to the heated exhaust air of the carbon dioxide recovery unit of the DAC facility; and when the segments are positioned in the third air passage, the segments can be cooled via the exhaust air of the carbon dioxide recovery unit of the DAC facility. This not only makes it possible to efficiently dry the surrounding air, but also to provide the carbon dioxide capture system with dry air at a temperature level that enables efficient carbon dioxide capture.

[0130] Preferably, the first and second air passages extend parallel to each other and are passed through in opposite directions. In this case, the rotation axis of the storage container extends parallel to the longitudinal axis of the air passages, which extends in the direction of airflow through both air passages. This allows for particularly efficient drying of the surrounding air. An optional third air passage preferably extends parallel to the first and second air passages, and the third air passage is passed through in the same direction as the second air passage.

[0131] In another configuration of the air drying apparatus described herein, the air drying apparatus is The storage unit is rotatable such that, as the storage unit rotates, its segments move from the first air passage to the second air passage, from the second air passage to the third air passage, and back to the first air passage. It is characterized by the following:

[0132] Preferably, the adsorbent that physically adsorbs water is zeolite, silica gel, or graphite. This also allows for particularly efficient drying of the surrounding air.

[0133] Furthermore, this specification includes, This is a DAC (Digital Acquisition Control) facility that captures carbon dioxide from the surrounding air. A system for drying the surrounding air where carbon dioxide capture is desirable, A cooling device that cools the dried ambient air, A carbon dioxide capture device that recovers carbon dioxide from the surrounding air that has been dried and cooled. In a DAC system equipped with, A DAC (Dry-Assisted Air Conditioning) system is characterized by having at least one drying device as described herein for drying the surrounding air. It is stated.

[0134] A DAC (Drift Carbon Dioxide Recovery) system described herein for recovering carbon dioxide from ambient air comprises a system for drying ambient air from which carbon dioxide recovery is desired, a cooling device for cooling the dried ambient air, and a carbon dioxide recovery device for recovering carbon dioxide from the dried and cooled ambient air, wherein the system for drying ambient air comprises at least one air drying device as described herein. The DAC system described herein can be operated efficiently with low energy demand for air drying.

[0135] In another configuration of a DAC facility as described herein, the DAC facility is characterized in that the system for drying ambient air has a plurality of parallel-connected air drying devices as described herein, and each of the parallel-connected air drying devices has the same number of air passages.

[0136] In another configuration of a DAC system as described herein, the DAC system is characterized in that the system for drying ambient air has a plurality of air dryers connected in series as described herein, wherein each of the series-connected air dryers has the same number of air passages and a different number of air passages.

[0137] In another configuration of a DAC system as described herein, the DAC system is characterized in that the carbon dioxide recovery unit has an adsorbent that physically adsorbs carbon dioxide, or is operated according to the principle of cryogenic gas separation.

[0138] Furthermore, this specification discloses a method for operating a DAC (Digital Accelerator) system.

[0139] In the operation of the DAC facility, ambient air is sent through at least one air drying device to dry the surrounding air, while exhaust air from the DAC facility's carbon dioxide capture unit is sent through the same device, causing the storage unit to rotate.

[0140] Embodiments of the present invention will be described illustratively with reference to the accompanying drawings. [Brief explanation of the drawing]

[0141] [Figure 1] This is a schematic diagram showing an embodiment of a rotatable pre-drying unit. [Figure 2] This is a schematic diagram showing an example of coating a rotatable pre-drying unit. [Figure 3] This is a schematic diagram showing an example of a carbon dioxide recovery device. [Figure 4a]This is a schematic diagram showing another embodiment of a carbon dioxide capture device. [Figure 4b] This is a schematic diagram showing another embodiment of a carbon dioxide capture device. [Figure 5] This is a schematic diagram illustrating an example of a method for capturing carbon dioxide. [Figure 6] This figure shows a significantly simplified representation of the first air drying apparatus described herein for the DAC equipment. [Figure 7] This figure shows the possible configurations of the air drying apparatus shown in Figure 6. [Figure 8] Figures 6 and 7 are schematic diagrams showing the first DAC facility described herein, equipped with the air drying apparatus described herein. [Figure 9] Figures 6 and 7 are schematic diagrams showing a second DAC facility as described herein, equipped with the air drying apparatus described herein. [Figure 10] This figure shows a significantly simplified representation of the second air drying apparatus described herein for the DAC equipment. [Figure 11] This is a schematic diagram showing a third DAC facility described herein, comprising the air drying apparatus described herein shown in Figures 6 and 7 and the air drying apparatus described herein shown in Figure 10. [Modes for carrying out the invention]

[0142] Figure 1 schematically shows an embodiment of a rotatable pre-drying unit 110. Reference numeral "101" illustrates the air inflow of process air on the drying side. Dried regenerated air 105 flows out on the regeneration side of the rotatable pre-drying unit 110. The rotatable pre-drying unit 110 can rotate about axis 103. Therefore, the rotation axis of the rotatable pre-drying unit extends in the axial direction. The flow direction of the process air 101 and regenerated air 105 extends radially. In the outer radial region on the drying side, there is a relatively high moisture pressure, which allows for good water adsorption even at lower flow velocities. As the radius decreases, the moisture pressure decreases as water adsorption progresses. At the same time, the flow velocity is increased, which supports the dynamics of adsorption, thereby achieving good drying even at relatively low moisture pressures. Reference numeral "104" represents dried process air. Reference numeral "105" represents dried regenerated air. The rotatable pre-drying unit 110 has at least one coating of at least one adsorbent for water on its outer surface to which the flow hits. Reference numeral "102" represents moist exhaust air.

[0143] Alternatively, in this arrangement of radial air guides, a defined coating pattern of adsorbent may be used. In the outer radial region, an adsorbent for rough drying (e.g., silica gel) is preferable, while in the inner radial region, an adsorbent for final drying (e.g., zeolite) is preferable.

[0144] As illustrated in Figure 1, the rotatable pre-drying unit may be an adsorption wheel or an adsorption heat exchanger.

[0145] Figure 2 schematically shows an embodiment of coating on the circumferential outer surface of a rotatable pre-drying unit 210. The air inflow of process air is indicated as "201". The air is guided through the rotatable pre-drying unit 210 and flows out again as dried process air 204. The dried regenerated air 205 flows into the rotatable pre-drying unit 210 and flows out again as moist exhaust air 202. The rotatable pre-drying unit 210 rotates about the indicated axis. Reference numeral "208" represents a coating with a first adsorbent (e.g., silica gel) that is particularly suitable for rough pre-drying of a gaseous medium (e.g., air) at relatively high partial pressures. Reference numeral "209" represents a coating with a second adsorbent (e.g., zeolite) that is particularly suitable for main drying of a gaseous medium (e.g., air) at relatively low partial pressures. Reference numeral "v dot" indicates volumetric flow rate. This means that of the 100% of the volumetric flow rate used, 80% to a maximum of 100% is used for the regeneration of the pre-drying unit. The remaining percentage is required for the de-drying and CO2 unit de-drying steps.

[0146] Such a coating pattern can be advantageous because it allows the dried process air to be dried to an even lower dew point compared to a rotatable pre-drying unit (e.g., an adsorption heat exchanger) that has only one type of coating. The distribution between the first and second coatings is preferably in a ratio of 70 / 30 to 90 / 10%.

[0147] As shown in Figure 2, the rotatable pre-drying unit may be an adsorption wheel or an adsorption heat exchanger.

[0148] Figure 3 schematically shows an embodiment of the carbon dioxide recovery apparatus 300. Pre-drying is performed using a rotatable pre-drying unit 310 (e.g., an adsorption heat exchanger). In this case, a gaseous medium (e.g., air) 301 flows radially into the rotatable pre-drying unit 310, is pre-dried, and then flows into the main drying unit 311. The drying unit 311 includes eight modules. Four modules of the drying unit 311 are in adsorption mode (Ads), while the other four modules are in desorption mode (Des). A portion of the main-dried gaseous medium flows into an intercooler 312. The gaseous medium flowing out of the intercooler 312 is guided to a CO2 unit 313. The CO2 unit 313 includes six modules, four of which are in adsorption mode (Ads) and two modules are in desorption mode (Des). A portion of the medium flowing out of the CO2 unit 313 is guided by the blower 314 to return to the rotatable pre-drying unit 310. The returned medium can be used to dry the rotatable pre-drying unit 310, particularly the adsorbent in the rotatable pre-drying unit 310. The flowing medium flows out of the rotatable pre-drying unit 310 as moist exhaust air 302. Another portion of the gaseous medium flowing out of the drying unit 311 is guided to the heat exchanger unit 315 for heat recovery. The heat is released and can be used to desorb CO2 from the modules of the CO2 unit 313. A portion of the gaseous medium can flow out of the CO2 unit 313 and into the heat exchanger unit 315 for heat recovery. The heat can be used to desorb water from the corresponding modules of the drying unit 311.

[0149] Figure 4 schematically shows another embodiment of the carbon dioxide recovery apparatus 400. Carbon dioxide recovery may be by direct air recovery (DAC) method. The apparatus based on a physical adsorbent mainly includes a rotatable pre-drying unit 410 consisting of one (or more arranged in parallel) adsorption heat exchangers, a drying unit 411 for main-drying a gaseous medium such as air, an intercooler 412, a CO2 adsorption unit 413, several heat exchanger units 416 and 417 for heat recovery, and blowers 414a,b,c arranged to draw air in. Dry regenerated air 405 can be used for pre-drying the rotating pre-drying unit 410.

[0150] In this system, there is a specified number of drying modules in the drying unit 411 and a specified number of CO2 modules in the CO2 unit 413. These drying modules and CO2 modules operate independently of each other during the main operating phases, "adsorption (Ads)" and "desorption (Des)". This allows the drying unit 411 and the CO2 unit 413 to be operated independently and optimized. This system is called a "separated system". Because the air mass flow rate through the system is constant, the exact number of drying modules required for CO2 adsorption in the CO2 modules are operated during the adsorption phase, thereby achieving the dew point temperature conditions required when the CO2 unit 413 flows in.

[0151] The proposed system has eight drying modules and six CO2 modules. Four modules each of the drying unit 411 and the CO2 unit 413 are always in the adsorption stage (air drying and CO2 absorption). The number of modules is determined based on the required process time for the drying unit and the CO2 unit (adsorption time to desorption time is 1:1 for the drying unit; adsorption time to desorption time is 1:0.5 for the CO2 unit). The total process time for one drying module is, for example, 4 hours (2 hours of adsorption, 2 hours of desorption), and the total process time for a CO2 module is, for example, 4.5 hours (3 hours of adsorption, 1.5 hours of desorption).

[0152] However, additional dry modules and CO2 modules may be placed in the system, provided that the total mass flow rate through the adsorption pathway in the system remains constant and the desorption of the dry modules and CO2 modules is completed before the desorption of the dry modules and CO2 modules must be interrupted.

[0153] A gaseous medium (e.g., moist ambient air) 401 is introduced through a rotatable pre-drying unit 410 (e.g., an sorbent heat exchanger) on the supply side. Water contained in the gaseous medium (e.g., air) is adsorbed by an sorbent material (preferably silica gel, zeolite, or a combination of multiple sorbent materials) and exits the rotatable pre-drying unit 410 with ambient air moisture at 80% relative humidity and 5°C, and dew points of 6°C and -10°C.

[0154] For example, for CO2 adsorption in zeolite, the water content in a gaseous medium, such as process air, is too high when the dew point is -10°C. This is because zeolite preferably adsorbs water instead of CO2. For this reason, the gaseous medium, such as process air, is guided to a drying unit 411 that dries the gaseous medium, such as air, to a dew point of at least -50°C, preferably -60°C.

[0155] In the drying unit 411, water is separated from the drawn-in and pre-dried gaseous medium by adsorption, for example, by zeolite (preferably 13X type zeolite). The total flow height in the drying unit 411 is, for example, 135 mm (similar to the CO2 module in the CO2 unit 413).

[0156] When the adsorption volume flow rate through the system is constant, and the average inflow velocity before the adsorbent material in the CO2 unit 413 is preferably 0.2 m / s, the inflow area of ​​the drying unit 411 is preferably configured such that an average inflow velocity of 0.2 m / s is generated before the adsorbent material. The average inflow velocity may be in the range of 0.1 to 0.4 m / s. The ratio between the inflow area of ​​the drying unit 411 and the inflow area of ​​the CO2 unit 413 is 1:1 (0.75 to 1.0 is also possible). The adsorption stage of the drying module is preferably operated until a water breakthrough (Durchbruch) corresponding to a dew point-temperature condition of at most -50°C is achieved. Adsorption heat is released during adsorption (exothermic process). As a result, a dry gaseous medium, such as dry air, exits the drying unit at a temperature approximately 7 K higher than the inflow temperature. If the moisture content of the incoming gaseous medium is higher or lower, the process time of the drying unit 411 can be adjusted so that the dew point-temperature condition of -50°C can be maintained as a water breakthrough at the outlet.

[0157] To achieve the best possible adsorption capacity in the subsequent CO2 unit 413, the dried gaseous medium is guided through the intercooler 412 and cooled to 5°C.

[0158] Next, the dried and cooled gaseous medium is guided through the CO2 unit 413, where CO2 is separated from the gaseous medium by adsorption, for example, by zeolite (preferably 13X type zeolite). Ideally, in this case, the CO2 stage is configured such that it has a flow height of preferably 135 mm. This provides a certain degree of equality between the drying unit 411 and the CO2 unit 413. Flow heights of 67 to 270 mm or 50% to 200% are also possible for direct air recovery applications.

[0159] To ensure the most efficient use of the pre-dried gaseous medium, the CO2 adsorption process is preferably carried out until a CO2 breakthrough of 140–160 ppm is achieved (after 3 hours in the proposed system). To increase the CO2 output at each adsorption stage, a single CO2 adsorption run (when the ambient air concentration is 420 ppm) is still significantly possible up to a CO2 breakthrough of 360 ppm, although this involves energy drawbacks. This is because excessive effort is invested in air drying rather than separating the CO2 from the adsorption stage.

[0160] The dry gaseous medium is used downstream of the CO2 unit 413 for H2O desorption (regeneration) in a rotatable pre-drying unit 410 (e.g., an adsorption heat exchanger) and for the drying stage in the drying unit 411.

[0161] Approximately 80% of the dry, gaseous medium from the CO2 unit 413 is used for regeneration of a rotatable pre-drying unit 410, such as an adsorption heat exchanger. This gaseous medium is led to the regeneration side of the rotatable pre-drying unit 410, such as an adsorption heat exchanger. Due to the partial pressure difference, the extremely dry regenerated air absorbs the moisture stored in the rotatable pre-drying unit 410 and exits the apparatus as moist exhaust air 402. The adsorbent material in the rotatable pre-drying unit 410 is regenerated to a low load state.

[0162] The remaining portion of the dry, gaseous medium from the CO2 unit 413 is used for periodic desorption in the drying and CO2 stages.

[0163] Furthermore, the thermal energy added during the attachment and detachment of the drying module of the drying unit 411 is recovered through two pathways.

[0164] In the first stage of H2O desorption, the heat stored in the sorbing material is transferred from the drying module to the next drying module, by the dry, gaseous medium that has just finished desorption. For this purpose, a mass flow rate of 7.5% of the adsorption mass flow rate is preferably used (0.5-15% is also possible), so that most of the residual heat is transferred within 30 minutes. In this case, the flow is carried out in the opposite direction to the flow direction of the adsorption stage.

[0165] For a separate desorption stage, a mass flow rate of preferably about 1.25% of the adsorption mass flow rate (0.1% to 5% is also possible) is used for purging (reducing partial pressure). Through an internally located heat exchanger, the adsorbent material and the incoming gaseous medium for purging are preferably heated to 150°C (temperatures in the range of 100°C to 200°C are also possible). To reduce the energy demand for heating, the gaseous medium flowing into the drying unit 411 is guided through an air-air heat exchanger 417 and preheated by the hot desorption air flowing out of the drying unit 411. The gaseous medium used for H2O desorption is introduced in the opposite direction to the adsorption flow direction. The desorption process is completed after 1 hour under the above conditions.

[0166] Next comes the third phase of H2O desorption, in which heat is transferred (WVS) from the newly desorbed, still-hot module to the next module where desorption begins, using a transfer mass flow rate of 7.5% (0.5-15% is also possible) of the adsorption mass flow rate. This heat transfer phase also continues for 30 minutes. This cools the adsorbent material in the newly desorbed module, so that it is immediately absorbent at the start of subsequent adsorption.

[0167] In this module, it is possible to operate four drying modules in adsorption mode and four drying modules in desorption mode, essentially in a continuous manner. Each of these modules can operate in adsorption mode for two hours and desorption mode for two hours.

[0168] The gaseous medium from the drying unit 411 can be discharged as exhaust air 420 via the air-to-air heat exchanger 417 and using the blower 414a.

[0169] During the desorption of the CO2 module, the module is evacuated to an absolute pressure of 10 mbar in the first desorption stage. The adsorbent material is then heated to 150°C (120°C to 200°C is also possible) using an internally located heat exchanger. During this process, the CO2 is desorbed and continuously drawn in by a vacuum pump 419. The desorbed CO2, with sufficient purity (higher than 95%, preferably higher than 99%), is introduced into the product pathway 422. This first desorption stage continues for 30 minutes.

[0170] During the adsorption stage, it is impossible to prevent a very small amount of residual moisture from entering the CO2 stage (due to a slight water breakthrough downstream of the drying unit 411). Therefore, to remove residual H2O, H2O desorption continues in the CO2 stage under negative pressure after CO2 desorption. To achieve this, a dry gaseous medium is introduced at a mass flow rate ratio of 3.4% of the adsorption mass flow rate (0.1% to 5% is also possible) while the desorption temperature is preferably raised to 200°C (150°C to 200°C is also possible). This medium is continuously drawn out by a vacuum pump 419, and in this case, an absolute pressure of preferably 100 mbar (10 to 800 mbar is also possible) is maintained ("two-stage desorption"). The dry gaseous medium introduced for desorption is guided through an air-air heat exchanger 416 and preheated by the high-temperature desorption air flowing out from this desorption stage 425. Thus, a portion of the desorption energy is recovered. Before reaching the vacuum pump 419, the desorbed gaseous water is condensed in the condenser 418 (outlet temperature 5°C), thus reducing the compression work of the vacuum pump 419. The desorbed air exits the vacuum pump 419 at a temperature higher than 150°C based on the compression. The high-temperature desorbed air is led to the drying unit 411, where it is used to preheat the purge air for the desorbing stage using the air-to-air heat exchanger 417. The second desorbing stage preferably continues for 35 minutes.

[0171] A heat transfer stage 427 follows to recover the heat stored in the adsorption material. In the heat transfer stage, a dry gaseous medium is introduced through the module at a mass flow rate of 7.5% (0.5-15% is also possible) of the adsorption mass flow rate under atmospheric pressure. This cools the adsorption material, making it immediately absorbent in the subsequent adsorption stage. The hot exhaust air from the heat transfer stage 427 is led to the drying unit 411, where the air from the heat transfer stage can be further heated between the drying modules via the air-to-air heat exchanger 416a. The heat transfer stage 427 of the CO2 module in the CO2 unit 413 continues for 25 minutes.

[0172] This allows for continuous operation of four CO2 modules in adsorption mode and two CO2 modules in desorption mode, with each CO2 module performing 3 hours of adsorption and 1.5 hours of desorption. The modules of CO2 unit 413 can be operated with a time difference of 45 minutes, or with a time difference of 60-30-60-30-60-30 minutes. The drying unit 411 and CO2 unit 413 can be operated with any desired time difference from each other.

[0173] From the CO2 unit 413, a portion of the gaseous medium may be guided by a vacuum pump 419 through a condenser 418 via a desorption path 424, and separated into residual air 421 and CO2 products 422 having a purity of more than 99%.

[0174] For the final drying of the CO2 unit, the H2O stored in the adsorbent material can be desorbed via the desorption path 425, through the air-air heat exchanger 416, condenser 418a, vacuum pump 419a, and air-air-air heat exchanger 417, as moist exhaust air 420.

[0175] A blower 414c is installed downstream of the CO2 unit 413, and the blower 414c draws the gaseous medium through the system. For a good compromise between pressure loss through the adsorption unit and CO2 output, it is advantageous for the average inflow velocity hitting the end face of the CO2 adsorption unit to be 0.2 m / s (0.1 to 0.4 m / s is also possible).

[0176] Figure 5 schematically shows an embodiment of the method according to the present invention for recovering CO2532. First, a gaseous medium is provided into a first air passage 528. Next, the gaseous medium is pre-dried in a rotating pre-drying unit 529, where the rotating pre-drying unit rotates around an axis and the first air passage is directed radially toward the rotating pre-drying unit. Furthermore, the pre-dried gaseous medium is dried in at least one drying unit 530. In another step 531, CO2 is adsorbed from at least the pre-dried gaseous medium in a CO2 unit and simultaneously recovered by desorption of CO2 in the CO2 unit.

[0177] Figure 6 schematically shows the first air drying unit 10 described herein in the DAC equipment 20, which is configured to recover carbon dioxide from the surrounding air. The DAC equipment 20 will be described in more detail below with reference to Figures 8, 9, and 11.

[0178] The air drying apparatus 10 shown in Figure 6 has a housing 11. This housing 11 defines a first air passage 12 and a second air passage 13, and separates these air passages from each other. The first air passage 12 is flowed through by ambient air.

[0179] Ambient air UL1 to be dried flows into the first air passage 12, and the dried ambient air UL2 flows out from the first air passage 12. The dried ambient air UL2 can be sent toward the carbon dioxide recovery device 23 of the DAC equipment 20. The second air passage 13 is flowed through by the exhaust air from the carbon dioxide recovery device 23 of the DAC equipment 20, from which carbon dioxide CO2 has been recovered in the carbon dioxide recovery device 23. The exhaust air AL1 from the carbon dioxide recovery device 23 flows into the second air passage 13, and the exhaust air AL2 from the DAC equipment 20 flows out from the second air passage 13.

[0180] The air drying device 10 further includes a rotating storage body 14. The rotating storage body 14 is rotatably driven. As the rotating storage body 14 rotates, segments of the storage body 14 are temporarily positioned in the first airflow channel 12 and temporarily in the second airflow channel 13. The duration or time interval during which segments of the rotating storage body 14 alternately are positioned in the first airflow channel 12 or the second airflow channel 13 depends on the rotation speed of the rotating storage body 14. The rotation direction of the storage body 14 is visualized by an arrow 18. The rotating storage body 14 carries an adsorbent that physically adsorbs water. When a segment of the rotating storage body 14 is located in the first airflow channel 12, the adsorbent on this segment absorbs water from the surrounding air UL1 to be dried, thereby drying the surrounding air. When each segment is subsequently located within the second airflow channel 13, the adsorbent of this segment releases the water previously absorbed in the region of the first airflow channel 12 into the exhaust air AL1 of the carbon dioxide recovery device 23 of the DAC equipment 20 in the second airflow channel 13 for the desorption of the segment. The exhaust air AL2 contains the water released into the exhaust air Al1.

[0181] The energy required for air drying in the air drying apparatus 10 described herein substantially corresponds to the energy required to rotate the rotating storage body 14. This enables particularly effective air drying of the ambient air.

[0182] The first air passage 12 and the second air passage 13 extend parallel to each other and are passed through in opposite directions by their respective air sources; that is, the first air passage 12 is passed through by ambient air UL1, UL2, and the second air passage 13 is passed through by exhaust air AL1, AL2. From Figure 7, it can be seen that the rotation axis 15 of the storage body 14 extends parallel to the flow directions of the two air passages 12 and 13, and therefore extends parallel to the longitudinal axes of the air passages 12 and 13 that extend in the flow directions of both air passages 12 and 13. In Figures 6 and 7, both air passages 12 and 13 are separated by the inner wall 11a of the housing 11 of the air drying device 10, and the outer wall 11b of the housing 11 defines both air passages 12 and 13 externally. In Figure 7, the rotation axis 15 of the storage body 14 preferably extends in the plane of the inner wall 11a.

[0183] In the embodiments shown in Figures 6 and 7, at each point in time, one half of the rotating storage body 14 is positioned in the first air passage 12, and the other half of the storage body 14 is positioned in the second air passage 13. However, due to the rotation of the storage body 14 around the rotation axis 15, the respective segments positioned in the first air passage 12 or the second air passage 13 change continuously.

[0184] The storage body 14 may be an air-permeable metal disc on which an adsorbent that physically adsorbs water is supported. This adsorbent may be, for example, zeolite, silica gel, or graphite.

[0185] The exhaust air AL1 from the carbon dioxide recovery device 23 of the DAC equipment 20, flowing through the second air channel 13, absorbs water received from the ambient air UL1 to be dried by the storage body 14 in the region of the first air channel 12, thereby forming a partial pressure sink (Partialdrucksenke) in the second air channel 13 for the attachment and detachment of the storage body 14. When one portion or section of the storage body 14 is located in the first air channel 12, this portion or section is passed through by the ambient air UL1, and the adsorbent absorbs water or moisture from the ambient air UL1 to be dried. Through continuous rotation or rotation of the storage body 14, a portion of the storage body 14 that was previously in the region of the first air channel 12 reaches the region of the second air channel 13, where the storage body 14 is then passed through by the exhaust air AL1 from the carbon dioxide recovery device 23 of the DAC equipment 20. Therefore, in the region of the second air passage 13, the adsorbent is desorbed, meaning that the water absorbed by the adsorbent is transferred to the exhaust air AL1 of the carbon dioxide recovery device 23 of the DAC equipment 20. The exhaust air AL1 of the carbon dioxide recovery device 23 of the DAC equipment 20 has an extremely low water vapor partial pressure, which allows it to efficiently absorb water or moisture from the adsorbent on the rotating storage body 14 in order to desorb the storage body 14. Furthermore, temperature equalization can be achieved between the temperature of the storage body 14 and the temperature of the air flowing through each air passage 12 and 13.

[0186] Figure 8 shows an overview of the DAC equipment 20, which has as its main components a system 21 for drying the surrounding air in which carbon dioxide is desirable to be absorbed, a cooling device 22 for cooling the dried surrounding air, and a carbon dioxide recovery device 23 for recovering carbon dioxide from the dried and cooled surrounding air.

[0187] In the DAC equipment 20 shown in Figure 8, the system 21 for drying the ambient air has two air dryers 10 connected in parallel, as shown in Figures 6 and 7. This allows the volumetric flow rate of the ambient air UL1 to be dried to be divided between the two air dryers 10. The dried ambient air UL2 exits both air dryers 10 and is cooled in a cooling device 22 upstream of the carbon dioxide recovery device 23.

[0188] According to Figure 8, the exhaust air AL1 from the carbon dioxide recovery unit 23 is guided through both air drying units 10, as is the ambient air UL1 to be dried.

[0189] In Figure 8, a filter device 24 is positioned upstream of the system 21 that dries the ambient air, allowing the ambient air to be filtered to remove, for example, dust or other particles before drying in the air dryer 10.

[0190] Figure 9 shows an improved version of the DAC equipment 20 shown in Figure 8. In Figure 9, the dried ambient air UL2 exiting both parallel-connected air dryers 10 is collected in a collector 25, which can then guide this ambient air UL2 through an air dryer 26, which may be based on the principle of a solid adsorption bed in, for example, the temperature swing method. If the air drying rate that can be provided by both parallel-connected air dryers 10 shown in Figures 8 and 9 is insufficient to supply the corresponding dried ambient air to the carbon dioxide recovery unit 23, the drying can be carried out in the area of ​​the air dryer 26 based on a solid adsorption bed. However, this is purely optional, as is the collector 25.

[0191] As shown in Figures 8 and 9, when the air drying system 21 has multiple air drying devices 10 connected in parallel, these air drying devices 10 are preferably identically configured and have at least the same number of air passages 12, 13.

[0192] Figure 11 shows an improved version of the DAC apparatus shown in Figure 8, in which two additional air dryers 10' are provided in parallel with the two parallel-connected air dryers 10 shown in Figures 6 and 7, with one air dryer 10' connected in series with each air dryer 10. The series-connected air dryers 10,10' differ in terms of airflow paths in Figure 11.

[0193] Figure 10 shows an overview of the air dryer 10', which has a first air passage 12 for ambient air and a second air passage 13 for the exhaust air AL1 of the carbon dioxide recovery device 23, in addition to another third air passage 16 for the exhaust air AL1 of the carbon dioxide recovery device 23. Therefore, both the third air passage 16 and the second air passage 13 are passed through by the exhaust air AL1 of the carbon dioxide recovery device 23.

[0194] In Figure 10, the exhaust air AL1 from the carbon dioxide recovery device 23 first flows into the third air passage 16, then flows out from this third air passage 16, is guided through the heating device 17 of the air dryer 10', and thereby flows into the second air passage 13, where it can flow out as exhaust air AL2 from the second air passage 13. The rotating storage body 14 is then rotatable such that, as the storage body 14 rotates, its segments are temporarily positioned in the first air passage 12, temporarily in the second air passage 13, and temporarily in the third air passage 16.

[0195] As the storage unit 14 rotates, the segments of the storage unit move from the first air passage 12 to the region of the second air passage 13, from the second air passage 13 to the third air passage 16, and then back to the first air passage 12 from the third air passage 16, as shown in Figure 10.

[0196] Next, when each segment of the rotating storage body 14 is located in the region of the first air channel 12, the adsorbent supported by this segment absorbs water from the surrounding air UL2, which needs to be further dried as shown in Figure 11, via physical adsorption. This surrounding air UL2 then exits the first air channel 12 as dried surrounding air UL3.

[0197] Next, when each segment of the rotating storage body 14 is located in the region of the second airflow channel 13, the adsorbent in this segment releases the moisture or water previously absorbed from the ambient air UL2 to be dried in the region of the first airflow channel 12 into the exhaust air AL1 of the carbon dioxide recovery device, which is heated in the region of the heating device 17 upstream of the second airflow channel 13.

[0198] When each segment of the rotating storage body 14 is located in the region of the third air passage 16, the unheated exhaust air AL1 from the carbon dioxide recovery device 23 cools the corresponding segment of the rotating storage body, thereby preventing each segment from re-entering the first air passage 12 at an excessively high temperature and heating the ambient air UL in the first air passage 12.

[0199] In Figure 11, rough drying is performed in the region of both air drying devices 10, and the main drying of the ambient air UL to be dried is performed in the region of both air drying devices 10'.

[0200] Figure 11 shows another collection unit 27. This additional collection unit 27 collects the exhaust air AL1 from the carbon dioxide recovery unit 23, thereby allowing this exhaust air AL1 to be supplied to the air drying units 10,10'.

[0201] Each carbon dioxide recovery unit 23 of the DAC equipment shown in Figures 8, 9, and 11 recovers carbon dioxide from the dried and cooled ambient air by physical adsorption, that is, via an adsorbent formed as a physical adsorbent. This adsorbent may also be a zeolite. Physical adsorption in the region of the carbon dioxide recovery unit 23 preferably utilizes the principle of a solid adsorption bed in a pressure-temperature swing method.

[0202] Alternative carbon dioxide capture systems can be operated according to known principles of cryogenic gas separation (utilizing the Joule-Thomson effect and adiabatic cooling of gas mixtures), in which the gas mixture containing carbon dioxide is first compressed, but the water vapor contained in the gas mixture is removed by an adsorbent prior to actual expansion.

[0203] The air drying apparatus described herein enables the effective drying of humid ambient air with low energy demand. Assuming that the ambient air UL1 to be dried has an ambient air temperature of 10°C, an air pressure of 1006 mbar, and a relative humidity of 100%, and that the exhaust air AL1 from the carbon dioxide recovery unit 23 of the DAC equipment 20 has a temperature of approximately 6°C, a relative humidity of approximately 0.1%, and a pressure of 1005 mbar, then dried ambient air UL2 having a pressure of 1005 mbar, a relative humidity of approximately 40%, and a temperature of approximately 7.3°C can be provided via the air drying apparatus 10 shown in Figures 6 and 7. In this case, the relative humidity of the dried ambient air UL2 is reduced by only about 60% compared to the ambient air UL1 to be dried. Under humid, warm supply conditions for ambient air UL1, the air drying rate is further improved. The air drying rate can be further increased by connecting air drying apparatuses 10 and 10' in series.

[0204] Therefore, in the DAC equipment 20 described herein, in the region of the air dryers 10, 10' described herein, the exhaust air AL1 from the carbon dioxide recovery unit 23 of the DAC equipment 20, which helps in the recovery of carbon dioxide from the dried and cooled ambient air, is used to dry the ambient air UL1. This allows the moisture removed from the ambient air UL1 to be dried by the adsorbent to be transferred to the exhaust air AL1 from the carbon dioxide recovery unit 23 of the DAC equipment.

[0205] Furthermore, this specification discloses a method for operating the DAC equipment 10 using at least one air drying device 10, 10' described herein. To dry the ambient air, ambient air is sent through the at least one air drying device 10, 10' according to the present invention, and exhaust air from the carbon dioxide collector 23 of the DAC equipment 20 is sent through the at least one air drying device 10, 10' according to the present invention, in which case the storage body 14 of the air drying device 10, 10' rotates. [Explanation of Symbols]

[0206] A device that captures 300,400 units of carbon dioxide. 101,201,301,401 Air inflow 102,202,302,402 Moist exhaust air 103,203 axis 104,204 Dry process air 105,205,405 Dry recycled air 206 Dry recycled air 208 Coating 110, 210, 310, 410 rotatable pre-drying unit 311,411 Drying Units 312,412 Intercoolers 313,413 CO2 units 314,414a,b,c Blower 315 Heat exchanger unit for heat recovery 416, 416a Air-to-air heat exchanger 417 Air-Air-Air Heat Exchanger 418,418a Condenser 419,419a Vacuum pump 420 Moist exhaust air 421 Residual air 422 CO2 production logistics 423 Route Detachable 424 Route Detachable 1 425 Route Detachable 2 426 Heat transfer pathways Drying unit 427 Heat Transfer Pathway CO2 528 Provision of a gaseous medium to the first air passage 529 Pre-drying of gaseous media in a rotating drying unit 530 Drying of pre-dried gaseous medium in the drying unit 531 Simultaneous recovery of CO2 by adsorption of CO2 from at least a pre-dried gaseous medium and desorption of CO2 in a CO2 unit. 532 Methods for capturing CO2 10. Air drying device 10' Air drying device 11 Housing 11a Wall 11b Wall section 12 First air passage 13. Second airflow channel 14 Storage containers 15. Axis of rotation 16. Third air passage 17 Heating device 18. Direction of rotation 20 DAC equipment 21. Air drying system 22 Cooling device 23 Carbon dioxide capture device 24 Filter device 25 Collection device 26. Air drying device 27 Collection device

Claims

1. A device (300, 400) for recovering carbon dioxide from a gaseous medium, A first air passage for a gaseous medium, A second air passage for the exhaust air of the aforementioned device, A rotatable pre-drying unit (110, 210, 310, 410) containing at least one adsorbent that physically adsorbs water and Includes, Apparatus (300, 400) wherein at least one rotatable pre-drying unit (110, 210, 310, 410) is rotatable around an axis, and a first air passage is directed radially toward the at least one rotatable pre-drying unit (110, 210, 310, 410).

2. At least one drying unit (311, 411) and at least one CO ２ The apparatus (300, 400) according to claim 1, comprising units (313, 413).

3. The aforementioned CO ２ The apparatus (300, 400) according to claim 2, wherein the unit (313, 413) includes at least one suction module and at least one detachment module.

4. The apparatus (300, 400) according to claim 2 or 3, wherein the drying unit (311, 411) includes at least four modules, the four modules being at least one desorption module, at least two heat transfer modules, and at least one adsorption module.

5. The apparatus (300, 400) according to at least one of claims 1 to 4, wherein a second air passage is directed axially to the rotatable pre-drying units (110, 210, 310, 410).

6. The apparatus (300, 400) according to at least one of claims 1 to 5, wherein the rotatable pre-drying units (110, 210, 310, 410) include at least two adsorbents that physically adsorb water.

7. The apparatus (300, 400) according to at least one of claims 1 to 6, wherein the adsorbent for physically adsorbing water comprises zeolite, graphite, aluminosilicate, MOF (metal-organic frame), or silica gel.

8. A method for capturing carbon dioxide (532), - Step (528) of providing a gaseous medium to the first air passage, - A step (529) of pre-drying a gaseous medium in a rotating pre-drying unit, - A step (530) of drying a pre-dried gaseous medium in at least one drying unit. and, -CO ２ In the unit, CO2 is extracted from a dried gaseous medium. ２ At the same time as adsorbing CO ２ CO in the unit ２ CO ２ Step (531) to recover and It has, Method (532), wherein the rotating pre-drying unit rotates about an axis, and the first air passage is directed radially toward the rotating pre-drying unit.

9. The method according to claim 8 (532), wherein the rotating pre-drying units (110, 210, 310, 410) include at least one adsorbent that adsorbs water.

10. Use of an apparatus according to at least one of claims 1 to 7 (300, 400) or the method according to claim 8 or 9 (532) for recovering carbon dioxide from a gaseous medium.

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