Combination of rotatable pre-drying unit with CO2 recovery

Abstract

Abstract “Combination of rotatable pre-drying unit with CO2 recovery” Here, there is described a device for recovering carbon dioxide from a gaseous medium, comprising: a first air flow channel for the gaseous medium, a second air flow channel for exhaust air from the device, at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water, wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel controls the at least one rotatable pre- drying unit radially. Furthermore, a method for recovering carbon dioxide and the use of the device and the method are disclosed. Abstract "Combination of rotatable pre-drying unit with CO2 recovery" Here, there is described a device for recovering carbon dioxide from a gaseous medium, comprising: a first air flow channel for the gaseous medium, a second air flow channel for exhaust air from the device, at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water, wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel controls the at least one rotatable pre- drying unit radially. Furthermore, a method for recovering carbon dioxide and the use of the device and the method are disclosed. 20 25 20 08 55 07 F eb 2 02 5 A b s t r a c t 2 0 2 5 2 0 0 8 5 5 0 7 F e b 2 0 2 5 " C o m b i n a t i o n o f r o t a t a b l e p r e - d r y i n g u n i t w i t h C O 2 r e c o v e r y " H e r e , t h e r e i s d e s c r i b e d a d e v i c e f o r r e c o v e r i n g c a r b o n d i o x i d e f r o m a g a s e o u s m e d i u m , c o m p r i s i n g : a f i r s t a i r f l o w c h a n n e l f o r t h e g a s e o u s m e d i u m , a s e c o n d a i r f l o w c h a n n e l f o r e x h a u s t a i r f r o m t h e d e v i c e , a t l e a s t o n e r o t a t a b l e p r e - d r y i n g u n i t , c o m p r i s i n g a t l e a s t o n e s o r b e n t f o r t h e p h y s i s o r p t i o n o f w a t e r , w h e r e i n t h e a t l e a s t o n e r o t a t a b l e p r e - d r y i n g u n i t i s d r i v a b l e i n a n a x i a l l y r o t a t i n g m a n n e r a n d t h e f i r s t a i r f l o w c h a n n e l c o n t r o l s t h e a t l e a s t o n e r o t a t a b l e p r e - d r y i n g u n i t r a d i a l l y . F u r t h e r m o r e , a m e t h o d f o r r e c o v e r i n g c a r b o n d i o x i d e a n d t h e u s e o f t h e d e v i c e a n d t h e m e t h o d a r e d i s c l o s e d .A b s t r a c t 2 0 2 5 2 0 0 8 5 5 0 7 F e b 2 0 2 5 1 / 6 1 / 6 110 105 104 102 103 101 Fig. 1 20 25 20 08 55 07 F eb 2 02 5 1 / 6 F e b 2 0 2 5 1 1 0 1 0 5 1 0 4 1 0 2 2 0 2 5 2 0 0 8 5 5 0 7 1 0 3 1 0 1 F i g . 1 F e b 2 0 2 5 1 0 4 2 0 2 5 2 0 0 8 5 5 0 7 1 0 3

Description

“Combination of rotatable pre-drying unit with CO2 recovery” Cross Reference

[001] The present application claims priority to German patent application no. 10 2024 103 685.0 filed on 9 February 2024, the entire specification of which is incorporated herein by cross reference in its entirety. Field of the Invention

[002] The invention relates to a device for recovering carbon dioxide from a gaseous medium, a method for recovering carbon dioxide from a gaseous medium, and the use of the device and the method for recovering carbon dioxide. Background

[003] The emission of carbon dioxide into the atmosphere is currently considered a major driver of climate change. Carbon capture and storage (CCS) technologies are efficient and effective techniques for reducing carbon dioxide emissions into the atmosphere.

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

[005] One technical application of capturing carbon dioxide is the direct air capture method (DAC). In this method, carbon dioxide is extracted from the ambient air using a separator. This allows pure carbon dioxide to be recovered, which can then be used in further processes.

[006] WO2016 / 005226A1, WO2015 / 185434A1 and WO2014 / 170184A1 describe exemplary methods for recovering carbon dioxide using a chemisorbent in a temperature-vacuum swing process. Amine-based chemisorbents often tend to age and degrade when the material comes into contact with oxygen at temperatures above approx. 60 °C. This can happen during the desorption phase at temperatures around 100 °C if countermeasures are not taken, such as, for example, an inert 2025200855   07 Feb 2025 atmosphere in the system by using steam or other gases. These protective measures are complex and expensive. During desorption, steam is introduced so that the residual oxygen is displaced and thus damage to the material through degradation is supposed to be prevented. Before the system returns to the adsorption phase (i.e. the absorption of CO2) after the desorption phase has ended, by bringing the sorbent material into contact with air, it is cooled down to approx. 50 °C. This means an additional process step, which can reduce the time and energy efficiency of the system.

[007] Physisorbents generally have a greater affinity for water than for CO2. For this reason, such systems have a pre-drying device for drying the air. This pre-drying is structurally and energetically complex.

[008] WO2022 / 109746A1 describes a method for recovering carbon dioxide using physisorbents in polar (cold, dry) regions, since these materials preferentially absorb water from the ambient air.

[009] When using physisorbents, one approach may be to limit the application area of such a system to polar regions of the earth, because the air there contains less water due to the low temperatures compared to temperate, subtropical or tropical climate zones. However, technical pre-drying cannot be completely dispensed with because it is not guaranteed that there will be a dew point temperature of, for example, -40 or -60 °C throughout the year. Furthermore, the effort required to install and operate a system in polar regions is enormous compared to developed regions of the earth.

[010] Knox et al., Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017, ICES-2017-188 disclose the use of physisorbents to separate CO2 from the cabin air of spaceships and space stations. Here one can find a so-called four-bed molecular sieve approach, which provided for connecting modules for pre-drying the cabin air and for CO2 separation.

[011] EP1142623A2 discloses a temperature-vacuum swing process for isolating carbon dioxide from a moist hot gas mixture. 2025200855   30 Sep 2026

[012] US2010251887A1 describes a method for isolating carbon dioxide from a gas mixture comprising a temperature swing adsorption step.

[013] WO2014 / 012966A1 discloses a device for an adsorption-desorption swing reaction.

[014] Any reference to publications cited in this specification is not an admission that the disclosures constitute common general knowledge in Australia.

[015] Disclosed herein is a device for recovering carbon dioxide from a gaseous medium, and a method for recovering carbon dioxide from a gaseous medium, which at least partially overcomes the above-mentioned disadvantages. Summary of the Invention [015a]  According to a first aspect there is provided a device for recovering carbon dioxide from a gaseous medium, comprising: a first air flow channel for the gaseous medium, a second air flow channel for exhaust air from the device, at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water, and at least one drying unit and at least one CO2 unit for adsorbing CO2, wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel flows radially towards the at least one axially rotatable pre-drying unit and wherein the rotatable pre-drying unit comprises at least two sorbents for the physisorption of water. [015b] According to a second aspect there is provided a method for recovering carbon dioxide, comprising the steps of: - providing a gaseous medium in a first air flow channel, - pre-drying the gaseous medium in a rotating pre-drying unit, - drying the pre-dried gaseous medium in at least one drying unit, - adsorbing CO2 from the dried gaseous medium in a CO2 unit and 2025200855   30 Sep 2026 simultaneously recovering CO2 by desorbing CO2 in a CO2 unit, wherein the rotating pre-drying unit rotates axially and the first air flow channel flows radially towards the axially rotating pre-drying unit and wherein the rotatable pre-drying unit comprises at least two sorbents for the physisorption of water.

[016] A device disclosed herein for recovering carbon dioxide from a gaseous medium comprises: -      a first air flow channel for the gaseous medium, -     a second air flow channel for exhaust air from the device, -      at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water,

[017] wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel controls the at least one rotatable predrying unit radially.

[18] The gaseous medium can be the atmosphere, ambient air, exhaust gases, e.g. from industrial plants, gas mixtures, point sources, etc. The gaseous medium comprises, inter alia, carbon dioxide (CO2). In a preferred embodiment, the gaseous medium is ambient air, also referred to herein as air.

[19] The device disclosed herein has a first air flow channel for the gaseous medium. The gaseous medium supplied in the first air flow channel can be process air. 2025200855   07 Feb 2025

[020] The device according to the invention also has a second air flow channel for exhaust air from the device. The exhaust air is preferably a moist gaseous medium from which carbon dioxide has been removed.

[021] Furthermore, a device according to the invention has at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water, wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel controls the at least one rotatable pre-drying unit radially.

[022] Rotatable within the meaning of the present invention means that the predrying unit is installed in such a way that it can rotate about its own axis and preferably rotates about its own axis during operation.

[023] The rotatable pre-drying unit is preferably a sorption wheel or a sorption heat exchanger. A sorption wheel is a wheel-shaped structural component that is coated with a sorbent on the outside. The sorption wheel or the sorption heat exchanger can rotate and a gaseous medium can flow towards it, from which a specific substance can be sorbed by means of the sorbent on the rotatable pre-drying unit.

[024] A device according to the invention can comprise a rotatable pre-drying unit. Alternatively, a device according to the invention can comprise at least two rotatable pre-drying units. If at least two rotatable pre-drying units are present, these can be arranged in parallel and / or in series.

[025] The at least one rotatable pre-drying unit is drivable in an axially rotating manner, i.e. it rotates about its own axis. The first air flow channel controls the at least one rotatable pre-drying unit radially. The gaseous medium thus flows in a radial direction.

[026] The sorbent for the physisorption of water is preferably arranged on the circumferential surface of the rotatable pre-drying unit so that the first air flow channel directly controls the sorbent, and the gaseous medium flowing through the first air flow channel comes into direct contact with the sorbent. 2025200855   07 Feb 2025

[027] As a result of the rotation of the rotatable pre-drying unit, a part of the rotatable pre-drying unit comes into contact with the gaseous medium, and the sorbent on the part of the rotatable pre-drying unit can at least partially absorb the moisture, i.e. the water in the gaseous medium. Due to the rotation, the rotatable pre-drying unit moves further and the portion of the sorbent wetted with moisture can move further to an area, the regeneration side, in which the sorbent can be dried. The sorbent can be dried by supplying so-called regeneration air. Due to the further rotation, the dried sorbent can be used again to dry gaseous medium. As a result, pre-dried gaseous medium can thus exit the rotatable pre-drying unit.

[028] The process and regeneration air flows in particular in a radial direction.

[029] The part of the rotatable pre-drying unit that comes into contact with the gaseous medium can be up to 50% of the circumferential surface of the rotatable predrying unit, preferably up to 30% of the circumferential surface of the rotatable predrying unit, more preferably up to 25% of the circumferential surface of the rotatable pre-drying unit.

[030] This arrangement of the flow direction is advantageous because there is a higher water partial pressure in the outer radial area of the circumferential surface on the drying side and thus the adsorption of moisture, i. e. the water of the gaseous medium, works well at a lower flow rate. As the radius becomes smaller, the water partial pressure drops due to the progressive water adsorption. At the same time, the flow rate is increased so that the kinetics of adsorption is supported and a good drying effect can be achieved even at lower water partial pressures.

[031] A device according to the invention can have at least one pre-conditioning unit. A pre-conditioning unit is a structural component by means of which the gaseous medium can be supplied in a suitable form to the other structural component(s), such as the at least one rotatable pre-drying unit. A pre-conditioning unit can, for example, cool or heat the gaseous medium to a defined temperature. A pre-conditioning unit can compress or expand the gaseous medium by means of pressure in addition to or as an alternative to setting the temperature. 2025200855   07 Feb 2025

[032] By using a pre-conditioning unit, a device according to the invention can also be used for different climatic conditions (e.g. higher H2O contents in the ambient air, at higher temperature and / or air humidity).

[033] In one embodiment, a device according to the invention comprises at least one drying unit and at least one CO2 unit.

[034] In the drying unit, the pre-dried gaseous medium can be dried to a specific moisture content. The drying unit preferably has at least one suitable material by means of which the moisture content can be set. The material can be distributed homogeneously in the drying unit. Alternatively, the material can also be distributed in layers in the drying unit. In particular, when the drying unit is constructed in layers, the drying unit can have a drying gradient. A first layer can therefore lead to a first drying to a specific moisture content. In the further layer of the drying unit, further drying to a specific moisture content can take place. A drying unit can have any number of layers. Ideally, the layers are coordinated.

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

[036] The drying unit can have at least four modules, wherein at least one module of the drying unit is a desorption module, at least two modules of the drying unit are thermal displacement modules, and at least one module of the drying unit is an adsorption module. Each module of the drying unit can be constructed separately with the suitable material for drying. Preferably, all modules of the drying unit are constructed identically with the suitable material or materials.

[037] The number of modules in the drying unit can be a multiple of the stated number of individual modules.

[038] A desorption module is understood to mean a structural unit that can desorb and preferably also adsorb a substance. The substance can be H2O. After desorbing 2025200855   07 Feb 2025 the substance, the desorption module can be utilized, for example, as an adsorption module and / or as a thermal displacement module.

[039] An adsorption module is understood to mean a structural unit that can adsorb and preferably also desorb a substance. The substance can be H2O. After adsorbing the substance, the adsorption module can be used, for example, as a desorption module and / or as a thermal displacement module.

[040] A thermal displacement module is understood to mean a structural unit that can dissipate or absorb heat. Depending on which phase of the method the thermal displacement module is in, the module can dissipate heat or absorb heat. In the thermal displacement phase before the desorption phase, the module can absorb heat (from another module that is in the thermal displacement phase and is giving off heat). For example, a thermal displacement module can be a former adsorption module. The adsorption of a substance in an adsorption module can simultaneously lead to an accumulation of heat, i.e. an increase in temperature in the adsorption module. The heat is preferably dissipated in order to ideally be used in another module, for example by desorbing an adsorbed substance by means of the heat supplied. The heat transfer can take place, for example, by air flowing through.

[041] The drying unit can have at least four modules. In alternative embodiments, the drying unit can also have more than four modules. The number of modules is preferably determined so that there is a constant mass flow through the device.

[042] The number of thermal displacement modules of the drying unit may be equal to the sum of the desorption modules of the drying unit and the adsorption modules of 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 thermal displacement modules, wherein z = 2, or an integer multiple of 2. 2025200855   07 Feb 2025

[043] There can be two drying modules in thermal displacement, with one module sending heat and one module receiving heat.

[044] The drying unit can be designed independently of the CO2 unit.

[045] A device according to the invention can further have at least one CO2 unit. A CO2 unit can adsorb a certain amount of carbon dioxide. The CO2 unit preferably has at least one material that can adsorb carbon dioxide.

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

[047] The CO2 unit can comprise at least one adsorption module and at least one desorption module. The CO2 unit can also have a module that can be used alternately as an adsorption module and as a desorption module. Preferably, the CO2 unit can adsorb CO2 or desorb CO2 depending on the stage of the method and can be designed accordingly.

[048] The CO2 unit may further comprise at least one thermal displacement module.

[049] Depending on the stage of the method, the module of the CO2 unit can preferably adsorb CO2 or desorb CO2 and perform thermal displacement, and thus be designed accordingly.

[050] The device contains a certain number of modules in the drying unit and modules in the CO2 unit, which can be operated independently of one another in the main operating phases "adsorption" and "desorption". This allows the drying unit and the CO2 unit to be operated individually in an optimized manner. This system is referred to as a "decoupled system". The air mass flow through the device is preferably constant, so that exactly as many modules in the drying unit are operated in the adsorption phase as are required for CO2 adsorption in the modules of the CO2 unit in order to represent the required dew point temperature condition at the inlet of the CO2 unit. 2025200855   07 Feb 2025

[051] In one embodiment, the second air flow channel radially controls the rotatable pre-drying unit. In such an embodiment, the first air flow channel and the second air flow channel run parallel. The exhaust air that is fed to the rotatable pre-drying unit through the second air flow channel can thus absorb moisture, i.e. water, and dry the sorbent.

[052] The rotatable pre-drying unit may have some type of sorbent for the physisorption of water.

[053] In one embodiment, the rotatable pre-drying unit may comprise at least two types of sorbents for the physisorption of water.

[054] The at least one sorbent for the physisorption of water can be selected from the group consisting of zeolite, graphite, aluminosilicate, MOF (Metal Organic Framework) or a silica gel.

[055] Preferably, the at least one sorbent is a silica gel. Alternatively, the at least one sorbent is zeolite.

[056] If there are at least two sorbents, this can be a combination of a silica gel and zeolite. The combination of sorbents can be arranged in layers. Preferably, one sorbent can be used to roughly dry the gaseous medium and the second sorbent can be used to finely dry the gaseous medium.

[057] A specific coating pattern can also be applicable for the arrangement of the radial air duct. In the outer radial area, a sorbent for rough drying is advantageous (e.g. silica gel), in the inner radial area, a sorbent for fine drying is advantageous (e.g. zeolite).

[058] A combination of at least two sorbents, i.e. at least two coatings of the rotatable pre-drying unit, is advantageous because it can dry the gaseous medium to an even lower dew point compared to a rotatable pre-drying unit having only one type of coating of sorbent. The distribution between the first and the second coating is 2025200855   07 Feb 2025 preferably in the ratio 70% / 30% to 90% / 10%, more preferably in the range of 75% / 25% to 80% / 20%.

[059] A device according to the invention can further comprise at least one intercooler.

[060] Preferably, an intercooler is arranged downstream of the drying unit. An intercooler can also be arranged upstream of the CO2 unit. In one possible variant, an intercooler is arranged between the drying unit and the CO2 unit.

[061] An intercooler preferably cools the incoming (gaseous) medium down to a defined temperature. The temperature is preferably <15 °C, more preferably <10 °C, even more preferably <6 °C. The incoming (gaseous) medium is particularly preferably cooled to a temperature of 5 °C.

[062] With additional and / or larger air conditioning units, cooling down to even lower temperatures (e.g. to -20 to -40 °C) could be achieved downstream of the drying unit.

[063] A device according to the invention can have at least one heat exchanger unit. The heat exchanger unit can be used in particular for heat recovery. By using a heat exchanger unit, the energy requirement supplied by external energy sources can be reduced and the energy efficiency of the device can thus be increased.

[064] 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.

[065] The energy requirement of the device according to the invention can be further reduced by using at least one heat pump. The heat pump can be used to recover the energy for desorption in the drying unit and / or the CO2 unit. The cold exhaust air from the heat pump can be used for cooling, e.g. in the rotatable pre-drying unit and / or the intercooler.

[066] A device according to the invention can further comprise at least one blower device. The blower can be used to guide the gaseous medium through the device. 2025200855   07 Feb 2025 The blower can be arranged on the inlet side and / or the outlet side of the device. If the blower is arranged on the inlet side, the gaseous medium is pressed into the device (for example into the rotating drying unit). If the blower is arranged on the outlet side of the device, the gaseous medium is drawn through the device by the suction created by the blower.

[067] There may be several blower devices or only one blower device.

[068] To keep the design as simple as possible, an attempt can be made to do without multiple blowers and set the air flow distribution using variable throttles, as long as the additional pressure loss that results is acceptable.

[069] The at least one drying unit and / or the at least one CO2 unit can also comprise at least one physisorbent or at least one sorbent. A physisorbent is a compound that can bind a substance (e.g. a gas such as carbon dioxide) through physical forces. A physisorbent ideally desorbs the adsorbed substance under controlled conditions. This can be done, for example, by the action of heat, pressure, the attachment of other substances with the release of the substance adsorbed first, etc.

[070] The physisorbents used are preferably robust, resistant to aging and commercially available on a large scale. In comparison to chemisorbents, there are generally no signs of aging or degradation in the temperature range used.

[071] The physisorbent can be a homogeneous substance or a mixture. Preferably, the at least one physisorbent is a solid. The at least one physisorbent can be selected from the group consisting of silica gel, zeolite, aluminosilicate and MOF (Metal Organic Framework).

[072] The drying unit preferably has a layered structure of physisorbents. 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 arranged in the inlet area of the drying unit so that the silica gel can carry out a first drying. The medium dried in this way is then guided through the at least one zeolite layer so that further drying of the medium can take place. 2025200855   07 Feb 2025

[073] Alternatively, the drying unit comprises at least one layer of silica gel and at least two layers of zeolite. A layer of zeolite, a so-called protective layer, can be arranged in the inlet area of the drying unit. The protective layer can be used to remove impurities from the gaseous medium in order to protect the following layers. At least one layer of silica gel can be arranged on the protective layer so that the silica gel can carry out a first drying process. The medium partially dried in this way is then guided through the at least one zeolite layer so that further drying of the partially dried medium can take place.

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

[075] Ideally, the sorbent(s) of the rotatable pre-drying unit are matched to the physisorbent(s) of the drying unit.

[076] The device according to the invention can be operated at a CO2 partial pressure in the range of approx. 380 to 480 ppm, preferably in the range of 400 to 450 ppm, particularly preferably 420 ppm. This results in a different ratio of CO2 and H2O partial pressures. For use under atmospheric conditions, an optimal configuration of the bed heights of the adsorption units can be advantageous.

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

[078] The CO2 unit can also have a layered or homogeneous structure of physisorbent(s). The CO2 unit preferably has a homogeneous structure of physisorbent(s). The physisorbent can be zeolite. The physisorbent can also be a mixture of at least two different zeolites. 2025200855   07 Feb 2025

[079] The CO2 unit preferably comprises at least two modules. The modules can each have an identical or different structure. In a preferred embodiment, each module comprises zeolite as a physisorbent, in particular all modules have an identical structure.

[080] The bed heights or the layer thicknesses in the drying unit and the CO2 unit can also have a certain ratio. The ratio can be in the range from 1.2 to 2.5, preferably in the range from 1.5 to 2.0 and more preferably in the range from 1.7 to 1.9. The ratio of the bed heights or the layer thicknesses of the drying unit and the CO2 unit is particularly preferably 1.8.

[081] Furthermore, the present invention relates to a method for recovering carbon dioxide, comprising the steps of: -      providing a gaseous medium in a first air flow channel, -      pre-drying the gaseous medium in a rotating pre-drying unit, -      drying the pre-dried gaseous medium in at least one drying unit, -     adsorbing CO2 from the dried gaseous medium in a CO2 unit and simultaneously recovering CO2 by desorbing CO2 in a CO2 unit, wherein the rotating pre-drying unit rotates axially and the first air flow channel controls the rotating predrying unit radially.

[082] Preferably, a method according to the invention is carried out in a device according to the invention. In doing so, it should also be possible to apply the features of the device to the method accordingly.

[083] One device can be used to carry out a method according to the invention. Alternatively, at least two devices can be used. The devices can be arranged in parallel.

[084] As already mentioned above, the gaseous medium can be the atmosphere, ambient air, exhaust gases, e.g. from industrial plants, gas mixtures, point sources, etc. The gaseous medium has, inter alia, carbon dioxide. The gaseous medium is preferably ambient air, also referred to herein as air. 2025200855   07 Feb 2025

[085] One step of the method according to the invention is the pre-drying of the gaseous medium, which is provided in a first air flow channel, in a rotating pre-drying unit. The gaseous medium flows radially towards the axially rotating pre-drying unit.

[086] The pre-drying is preferably carried out to a moisture content of the gaseous medium of 0.5 mass%, more preferably 0.25 mass%, even more preferably 0.1 mass%.

[087] The rotating pre-drying unit can be a sorption wheel or a sorption heat exchanger. A sorption wheel is a wheel-shaped structural component that is coated with a sorbent on the outside. The sorption wheel or the sorption heat exchanger can rotate and a gaseous medium can flow towards it, from which a specific substance can be sorbed by means of the sorbent.

[088] In one embodiment, the rotating pre-drying unit comprises at least one sorbent for adsorbing water. The sorbent can be the sorbents mentioned herein. There can be one sorbent or a combination of at least two sorbents.

[089] In one embodiment, the at least one sorbent is a combination of two sorbents. The two sorbents may be a first layer of silica gel and a second layer of zeolite.

[090] A method according to the invention further comprises the step of drying the pre-dried gaseous medium in a drying unit. The drying unit can comprise several modules, as described herein for the device.

[091] The modules of the drying unit can be in different operating states, wherein 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 thermal displacement is performed in at least two modules of the drying unit.

[092] The number of modules in the drying unit in the individual operating states can be a multiple of the stated number of individual modules. 2025200855   07 Feb 2025

[093] The drying unit can also have more than four modules. The modules can in turn be in the operating states of adsorption of H2O, desorption of H2O and thermal displacement. The ratio of the individual operating states can be distributed among the individual modules as follows: Number of drying modules = x desorption modules + y adsorption modules + z thermal displacement modules, wherein z = 2, or an integer multiple of 2.

[094] Drying can be carried out using at least one suitable material, by means of which the moisture content can be set. The material can be present as a homogeneous material. Alternatively, the material can also be present in layers. In particular, when present in layers, a drying gradient can be present. This is to say, a first layer can result in a first drying to a certain moisture content. In the next layer, further drying to a certain moisture content can take place. There can be any number of layers. Ideally, the layers are coordinated with each other. The layer(s) may be at least one physisorbent, as described herein.

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

[096] Preferably, the gaseous medium is conditioned before drying. Conditioning is used in particular to supply the gaseous medium to the method at an adequate temperature and / or adequate pressure.

[097] In one embodiment, a method according to the invention comprises cooling the gaseous medium before adsorbing the CO2. The cooling of the gaseous medium can be carried out by an intercooler. Alternatively, other structural components for controlling the temperature of the gaseous medium are also conceivable. For example, it can be an air-water heat exchanger, an air-air heat exchanger and / or an air-air-air heat exchanger. 2025200855   07 Feb 2025

[098] The incoming gaseous medium is preferably cooled down to a defined temperature. The temperature is preferably <15 °C, more preferably <10 °C, even more preferably <6 °C. The incoming gaseous medium is preferably cooled to a temperature of 5 °C.

[099] A method according to the invention may comprise the step of recovering heat, as described above.

[100] The energy requirement of a method according to the invention can be reduced by using at least one heat pump, as described above.

[101] In one embodiment, a method according to the invention comprises the step of transporting the gaseous medium by means of a blower. The blower can correspond to the blower of a device according to the invention.

[102] The blower can be used to guide the gaseous medium through the device. The blower can be arranged on the inlet side and / or the outlet side of the device. If the blower is arranged on the inlet side, the gaseous medium is pressed into the device (for example into the pre-conditioning unit). If the blower is arranged on the outlet side of the device, the gaseous medium is drawn through the device by the suction created by the blower.

[103] In a method according to the invention, the adsorbed CO2 is preferably desorbed by heating and under vacuum. The unit in which the CO2 is adsorbed is heated to a defined temperature. The heating causes the CO2 to be released from the unit and can preferably be discharged with high purity.

[104] In a method according to the invention, the H2O is preferably adsorbed simultaneously in at least one module in the drying unit, while the H2O is desorbed in at least one other module of the drying unit. If the CO2 is desorbed in at least one module of a CO2 unit, the CO2 is preferably adsorbed simultaneously in at least one other module of the CO2 unit. 2025200855   07 Feb 2025

[105] The CO2 can preferably be discharged from the device or the method in a purity of >80%, more preferably in a purity of >90%, even more preferably in a purity of >95%. In some embodiments, the CO2 is discharged in a purity of >99%.

[106] The adsorbed CO2 can be desorbed by heating to a temperature of >50 °C, in particular >80 °C, preferably >100 °C, more preferably >120 °C, even more preferably >140 °C. Preferably, in a method according to the invention, no steam is required for the desorption of the CO2. Preferably, the desorption of the CO2 takes place under vacuum at a pressure of 10 mbar absolute.

[107] A method according to the invention may further comprise the step of cooling the gaseous medium before adsorbing the CO2. Said cooling may be carried out by means of an intercooler, as described herein.

[108] A method according to the invention and a device according to the invention can be used in a direct air capture method.

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

[110] The carbon dioxide recovered can be used as a starting material for other compounds. For example, the carbon dioxide can be used as a starting material for the production of plastics, e-fuels, etc.

[111] Exemplary embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1 shows schematically an exemplary embodiment of a rotatable pre-drying unit, Fig. 2 shows schematically an exemplary embodiment of a coating of a rotatable pre-drying unit, Fig. 3 shows schematically an exemplary embodiment of a device for recovering carbon dioxide, 2025200855   07 Feb 2025 Fig. 4 shows schematically another exemplary embodiment of a device for recovering carbon dioxide, and Fig. 5 shows schematically an exemplary embodiment of a method for recovering carbon dioxide.

[112] Figure 1 shows schematically an exemplary embodiment of a rotatable predrying unit 110. 101 represents the air inlet of process air on the drying side. Dry regeneration air 105 exits on the regeneration side of rotatable pre-drying unit 110. Rotatable pre-drying unit 110 can rotate about axis 103. The axis of rotation of the rotatable pre-drying unit runs therefore axially. Process air 101 and regeneration air 105 flow in a radial direction. In the outer radial area on the drying side there is a higher water partial pressure and thus the adsorption of water works well at a lower flow rate. As the radius becomes smaller, the water partial pressure drops due to the progressive water adsorption. At the same time, the flow rate is increased so that the kinetics of the adsorption is supported and a good drying effect is achieved even at lower water partial pressures. 104 represents the dried process air. 105 represents dry regeneration air. Rotatable pre-drying unit 110 can have at least one coating of at least one sorbent for water on the outer surface towards which the air flows. 102 represents the moist exhaust air.

[113] Alternatively, a specific coating pattern of sorbents can be applicable for this arrangement of the radial air duct. In the outer radial area, a sorbent for rough drying is advantageous (e.g. silica gel), in the inner radial area, a sorbent for fine drying is advantageous (e.g. zeolite).

[114] The rotatable pre-drying unit, as shown in Figure 1, can be a sorption wheel or a sorption heat exchanger.

[115] Figure 2 shows schematically an exemplary embodiment of a coating on the outer circumferential surface of a rotatable pre-drying unit 210. The air inlet of the process air is shown as 201. The air is guided through rotatable pre-drying unit 210 and exits as dry process air 204. Dry regeneration air 205 enters rotatable pre-drying unit 210 and exits as moist exhaust air 202. Rotatable pre-drying unit 210 rotates about the axis shown. 208 represents the coating with a first sorbent, which is 2025200855   07 Feb 2025 particularly suitable for rough pre-drying of the gaseous medium (e.g. air) at higher partial pressures (e.g. silica gel). 209 represents the coating with a second sorbent, which is particularly suitable for fine drying of the gaseous medium (e.g. air) at lower partial pressures (e.g. zeolite). “v” stands for the volume flow. This means that of the 100% of the volume flow used, 80 to a maximum of 100% is used for the regeneration of the pre-drying unit. The remaining portion is required for the desorption steps of the drying and CO2 unit.

[116] Such a coating pattern can be advantageous because it can dry the dry process air to an even lower dew point compared to a rotatable pre-drying unit (e.g. a sorption heat exchanger) with only one type of coating. The distribution between the first and second coating is preferably at a ratio of 70 / 30 to 90 / 10%.

[117] The rotatable pre-drying unit, as shown in Figure 2, can be a sorption wheel or a sorption heat exchanger.

[118] Figure 3 shows schematically of an exemplary embodiment of a device for recovering carbon dioxide 300. Pre-drying is carried out by means of a rotatable predrying unit 310 (e.g. a sorption heat exchanger). Gaseous medium (e.g. air) 301 enters rotatable pre-drying unit 310 radially and enters drying unit 311 in a pre-dried state for fine drying. Drying unit 311 comprises eight modules. Four modules of drying unit 311 are in adsorption mode (Ads) while four other modules are in desorption mode (Des). A portion of the finely dried gaseous medium enters an intercooler 312. The gaseous medium that exits intercooler 312 is fed to CO2 unit 313. CO2 unit 313 comprises six modules, with four modules in adsorption mode (Ads) and two modules in desorption mode (Des). A portion of the medium exiting CO2 unit 313 is returned to rotatable pre-drying unit 310 by means of blower 314. The returned medium can be used to dry rotatable pre-drying unit 310, in particular the sorbent of rotatable pre-drying unit 310. The exiting medium exits rotatable pre-drying unit 310 as moist exhaust air 302. Another portion of the gaseous medium exiting drying unit 311 is led to heat exchanger units for heat recovery 315. The heat is dissipated and can be used to desorb the CO2 from the modules of CO2 unit 313. A portion of the gaseous medium may exit CO2 unit 313 and enter the heat exchanger 2025200855   07 Feb 2025 units for heat recovery 315. The heat may be used to desorb water from the corresponding modules of drying unit 311.

[119] Figure 4 shows schematically another exemplary embodiment of a device for recovering carbon dioxide 400. The carbon dioxide can be recovered using a direct air capture method (DAC method). The device based on physisorbents substantially comprises a rotatable pre-drying unit 410 consisting of one (or several arranged in parallel) sorption heat exchanger(s), one drying unit 411 for fine drying the gaseous medium, such as air, one intercooler 412, one CO2 adsorption unit 413, several heat exchanger units 416 and 417 for heat recovery and a blower 414 a, b, c arranged in suction mode. Dry regeneration air 405 can be used for pre-drying rotating pre-drying unit 410.

[120] The system includes a certain number of drying modules in drying unit 411 and CO2 modules in CO2 unit 413, which are operated independently of one another in the main operating phases "adsorption" (Ads) and "desorption" (Des). This allows drying unit 411 and CO2 unit 413 to be operated in an individually optimized manner. This system is referred to as a "decoupled system". The air mass flow through the system is constant, so that exactly as many drying modules are operated in the adsorption phase as are required for the CO2 adsorption in the CO2 modules in order to represent the required dew point temperature condition at the inlet of CO2 unit 413.

[121] The proposed system consists of 8 drying modules and 6 CO2 modules. Here, 4 modules of drying unit 411 and CO2 unit 413 are always in the adsorption phase (air drying and CO2 absorption). The number of modules is determined by the required process times of the drying and CO2 units (drying unit adsorption to desorption time 1:1; CO2 unit adsorption to desorption time 1:0.5). The total process time of a drying module is, for example, 4 h (2 h adsorption, 2 h desorption), the total process time of a CO2 module is, for example, 4.5 h (3 h adsorption, 1.5 h desorption).

[122] However, a different number of drying and CO2 modules can be arranged in the system, as long as the total mass flow of the adsorption path through the system 2025200855   07 Feb 2025 is constant and the desorption of the drying and CO2 modules is completed before the adsorption phases of the drying and CO2 modules have to be terminated.

[123] Gaseous medium (e.g. the moist ambient air) 401 is passed through rotatable pre-drying unit 410 (e.g. the sorption heat exchanger) on the supply air side. The water contained in the gaseous medium (e.g. in the air) is adsorbed on the sorption material (preferably silica gel or zeolite, or a combination of several sorption materials) and leaves rotatable pre-drying unit 410 at an ambient humidity of 80% relative humidity and 5 °C with a temperature of 6 °C and a dew point of -10 °C.

[124] For the adsorption of CO2, e.g. on zeolites, the water content in the gaseous medium, e.g. process air, is too high at a dew point of -10 °C, since a zeolite preferentially adsorbs water instead of CO2. For this reason, the gaseous medium, e.g. the process air, is guided to a drying unit 411 for fine drying of the gaseous medium, e.g. air, to a dew point of at least -50 °C, preferably -60 °C.

[125] In drying unit 411, the water is separated from the sucked in and pre-dried gaseous medium by means of adsorption, e.g. on a zeolite (preferably a zeolite Type 13X). The total bed height in the drying unit 411 is, for example, 135 mm (as with the CO2 modules in CO2 unit 413).

[126] The inflow area of drying unit 411 is configured such that an average inflow velocity of 0.2 m / s is preferably achieved upstream of the sorption material if, with a constant adsorption volume flow through the system, the average inflow velocity upstream of the sorption material of CO2 unit 413 is preferably 0.2 m / s. The average inflow velocity can also be in the range from 0.1 to 0.4 m / s. The ratio of the inflow areas between drying unit 411 and CO2 unit 413 is 1:1 (0.75 to 1.0 is also possible). The adsorption phase of a drying module is preferably operated until water breakthrough occurs at the latest, corresponding to a dew point temperature condition of -50 °C. Adsorption heat is released during adsorption (exothermic process). As a result, the dry gaseous medium, e.g. the dry air, exists the drying unit with a temperature approx. 7 K higher than the inlet temperature. If the moisture contents of the incoming gaseous medium are higher or lower, the process time of 2025200855   07 Feb 2025 drying unit 411 can be adjusted so that the dew point temperature condition of -50 °C as water breakthrough at the outlet can be maintained.

[127] In order to achieve the best possible adsorption capacity in subsequent CO2 unit 413, the dried gaseous medium is passed through an intercooler 412 and cooled back to 5 °C.

[128] The dry and cooled gaseous medium is then passed through a CO2 unit 413, in which the CO2 is separated from the gaseous medium by adsorption, e.g. on a zeolite (preferably on a zeolite Type 13X). The CO2 stage is ideally configured in such a way that it has a bed height of preferably 135 mm. This ensures a certain degree of equal parts in drying unit 411 and CO2 unit 413. A bed height of 67 to 270 mm or 50% to 200% is also possible for the direct air capture application.

[129] The CO2 adsorption process is carried out up to a CO2 breakthrough of preferably 140 to 160 ppm in order to ensure the most efficient use of the pre-dried gaseous medium (this is achieved after 3 h in the proposed system). Operation of the CO2 adsorption is still reasonably possible up to a CO2 breakthrough of 360 ppm (at a concentration of 420 ppm in the ambient air) in order to increase the CO2 yield per adsorption phase, although this results in an energetic disadvantage, since disproportionately more effort is invested in air drying than CO2 can be separated from the adsorption phase.

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

[131] Approx. 80% of the dry gaseous medium from CO2 unit 413 is used for the regeneration of rotatable pre-drying unit 410, e.g. the sorption heat exchanger. This gaseous medium is passed to the regeneration side of rotatable pre-drying unit 410, e.g. the sorption heat exchanger. Due to the partial pressure difference, the very dry regeneration air absorbs the moisture stored in rotatable pre-drying unit 410 and leaves the device as moist exhaust air 402. The sorption material of rotatable predrying unit 410 is regenerated to a low loading state. 2025200855   07 Feb 2025

[132] The remaining portion of the dry gaseous medium from CO2 unit 413 is used for the cyclic desorption of the drying stage and CO2 stage.

[133] Furthermore, the heat energy applied in the desorption phase of the drying modules in drying unit 411 is recovered in two ways.

[134] In the first phase of H2O desorption, the heat stored in the sorption material is displaced by means of a dry gaseous medium from a drying module that has just finished desorption to a drying module that will go into desorption next. For this purpose, a mass flow to the extent of 7.5 % of the adsorption mass flow is preferably used (0.5 to 15% is also possible), so that a large part of the residual heat is displaced within 30 minutes. The flow is opposite to the flow direction of the adsorption phase.

[135] For the further desorption phase, a mass flow to the extent of preferably 1.25% of the adsorption mass flow (0.1 to 5% is also possible) is used for flushing (reduction of the partial pressure). The sorption material and the inflowing gaseous medium are heated to preferably 150 °C for flushing via the internal heat exchanger (temperatures in the range of 100 to 200 °C are also possible). In order to reduce the energy required for heating, the gaseous medium entering drying unit 411 is passed through an air-air heat exchanger 417 and pre-heated with the hot desorption air exiting drying unit 411. The gaseous medium used for the H2O desorption is introduced in the opposite direction to the direction of flow of the adsorption. The desorption process is completed after a period of one hour under the conditions mentioned.

[136] Next, the third part of the H2O desorption follows including the thermal displacement (WVS) from the just desorbed, still hot module to the next module at the beginning of the desorption with a displacement mass flow of 7.5% of the adsorption mass flow (0.5 to 15% is also possible). This thermal displacement phase also lasts 30 minutes. As a result, the sorption material of the just desorbed module cools down so that it is immediately ready for absorption at the beginning of the subsequent adsorption. 2025200855   07 Feb 2025

[137] This mode enables a quasi-continuous operation of 4 drying modules in adsorption and 4 drying modules in desorption, each of which is operated for 2 hours in adsorption and 2 hours in desorption.

[138] The gaseous medium from drying unit 411 can be discharged as exhaust air 420 via an air-air heat exchanger 417 by means of blower 414a.

[139] During the desorption of the CO2 modules, the module is evacuated to an absolute pressure of 10 mbar in the first desorption phase. The sorption material is then heated to 150 °C by means of the internal heat exchanger (120 to 200 °C are also possible). In doing so, the CO2 is desorbed and continuously sucked off by vacuum pump 419. If the purity is sufficient (>95%, preferably >99%), desorbed CO2 is passed into product path 422. This first desorption phase lasts 30 minutes.

[140] Since it cannot be prevented during the adsorption phase that a very small amount of residual moisture can enter into the CO2 stage (due to a small amount of water breakthrough downstream of drying unit 411), the CO2 desorption is followed by H2O desorption in the CO2 stage under negative pressure in order to remove the residual H2O load. For this purpose, a dry gaseous medium of 3.4% mass flow proportion of the adsorption mass flow (0.1 to 5% is also possible) is introduced while raising the desorption temperature to preferably 200 °C (150 to 200 °C is also possible), which is continuously sucked off by vacuum pump 419, wherein a pressure of preferably 100 mbar absolute (10 to 800 mbar is also possible) is maintained ("2-stage desorption"). The dry gaseous medium introduced for desorption is passed through an air-air heat exchanger 416 and preheated with the hot desorption air exiting this desorption phase 425. In this way, a portion of the desorption energy is recovered. Upstream of vacuum pump 419, the desorbed and gaseous water is condensed at a condenser 418 (outlet temperature 5 °C), so that the compressor work of vacuum pump 419 is reduced. Due to the compression, the desorption air leaves vacuum pump 419 at a temperature of greater than 150 °C. The hot desorption air is passed to drying unit 411 and used there by means of an air-air heat exchanger 417 to preheat the purge air of the desorption phase. The second desorption phase preferably lasts 35 minutes. 2025200855   07 Feb 2025

[141] In order to recover the heat stored in the sorption material, a thermal transfer phase 427 follows, in which dry gaseous medium is passed through the module under atmospheric pressure with a mass flow rate of 7.5% of the adsorption mass flow (0.5 to 15% is also possible). As a result, the sorption material cools down and is immediately ready for absorption in the subsequent adsorption phase. The hot exhaust air from thermal displacement phase 427 is passed to drying unit 411 in order to additionally heat the air from the thermal displacement phase between the drying modules via an air-air heat exchanger 416a. Thermal displacement phase 427 of the CO2 modules in CO2 unit 413 lasts 25 minutes.

[142] This enables a quasi-continuous operation of 4 CO2 modules in adsorption and 2 CO2 modules in desorption, each of which is operated for 3 hours in adsorption and 1.5 hours in desorption. The modules of CO2 unit 413 can be operated with a time offset of 45 minutes each or with an offset of 60-30-60-30-60-30 minutes. Drying unit 411 and CO2 unit 413 can be operated offset from one another as desired.

[143] From CO2 unit 413, a portion of the gaseous medium can be guided via a desorption path 424 through a condenser 418 by means of a vacuum pump 419 and divided into residual air 421 and CO2 product stream 422 with a purity >99%.

[144] For the fine drying of the CO2 unit, the H2O stored in the sorbent material can be discharged as moist exhaust air 420 via a desorption path 425 via an air-air heat exchanger 416, a condenser 418a, a vacuum pump 419a, and an air-air-air heat exchanger 417.

[145] A blower 414c is attached downstream of CO2 unit 413, which sucks the gaseous medium through the system. As a good compromise between pressure loss across the adsorption units and CO2 yield, an average inflow velocity of the front surfaces of the CO2 adsorber units of 0.2 m / s is favorable (0.1 to 0.4 m / s is also possible).

[146] Figure 5 schematically shows an embodiment of a method according to the invention for recovering CO2 532. First, a gaseous medium is provided in a first air 2025200855   07 Feb 2025 flow channel 528. The gaseous medium is then pre-dried in a rotating pre-drying unit 529, wherein the rotating pre-drying unit rotates axially and a first air flow channel controls the rotating pre-drying unit radially. The pre-dried gaseous medium is then dried in at least one drying unit 530. In a further step 531, the CO2 from the at least pre-dried gaseous medium is adsorbed in a CO2 unit and simultaneously CO2 is recovered by desorbing CO2 in a CO2 unit.

[147] Disclosed herein are the following forms: 1.    A device for recovering carbon dioxide (300, 400) from a gaseous medium, comprising: a first air flow channel for the gaseous medium, a second air flow channel for exhaust air from the device, at least one rotatable pre-drying unit (110, 210, 310, 410), comprising at least one sorbent for the physisorption of water, wherein the at least one rotatable pre-drying unit (110, 210, 310, 410) is drivable in an axially rotating manner and the first air flow channel controls the at least one rotatable pre-drying unit (110, 210, 310, 410) radially. 2.    The device (300, 400) according to form 1, comprising at least one drying unit (311, 411) and at least one CO2 unit (313, 413). 3.    The device (300, 400) according to form 2, wherein the CO2 unit (313, 413) comprises at least one adsorption module and at least one desorption module. 4.    The device (300, 400) according to form 2 or 3, wherein the drying unit (311, 411) comprises at least four modules, and wherein the modules are at least one desorption module, at least two thermal displacement modules and at least one adsorption module. 5.    The device (300, 400) according to at least one of forms 1 to 4, wherein the second air flow channel controls the rotatable pre-drying unit (110, 210, 310, 410) axially. 2025200855   07 Feb 2025 6.    The device (300, 400) according to at least one of forms 1 to 5, wherein the rotatable pre-drying unit (110, 210, 310, 410) comprises at least two sorbents for the physisorption of water. 7.    The device (300, 400) according to at least one of forms 1 to 6, wherein the at least one sorbent comprises zeolite, graphite, aluminosilicate, MOF (Metal Organic Framework) or a silica gel for the physisorption of water. 8.    A method for recovering carbon dioxide (532), comprising the steps of: - providing a gaseous medium in a first air flow channel (528), - pre-drying the gaseous medium in a rotating pre-drying unit (529), - drying the pre-dried gaseous medium in at least one drying unit (530), - adsorbing CO2 from the dried gaseous medium in a CO2 unit and simultaneously recovering CO2 by desorbing CO2 in a CO2 unit (531), wherein the rotating pre-drying unit rotates axially and the first air flow channel controls the rotating pre-drying unit radially. 9.    The method (532) according to form 8, wherein the rotating pre-drying unit (110, 210, 310, 410) comprises at least one sorbent for the adsorption of water. 10. Use of a device (300, 400) according to at least one of forms 1 to 7, or of a method (532) according to form 8 or 9 for recovering carbon dioxide from a gaseous medium. 2025200855   07 Feb 2025 List of reference numerals 300, 400 device for recovering carbon dioxide 101, 201, 301, 401 air inlet 102, 202, 302, 402 moist exhaust air 103, 203    axis 104, 204    dried process air 105, 205, 405      dry regeneration air 206 dry regeneration air 208 coating 110, 210, 310, 410 rotatable pre-drying unit 311, 411     drying unit 312, 412    intercooler 313, 413    CO2 unit 314, 414a, b, c    blower 315 heat exchanger units for heat recovery 416, 416a   air-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 product stream 423  path desorption 424  path desorption 1 425  path desorption 2 426  path thermal displacement drying unit 427  path thermal displacement CO2 528 providing a gaseous medium in a first air flow channel 529 pre-drying of the gaseous medium in a rotating drying unit 530 drying the pre-dried gaseous medium in a drying unit 531 adsorbing CO2 from the at least pre-dried gaseous medium and simultaneously recovering CO2 by desorbing CO2 in a CO2 unit 532 method for recovering CO2

Claims

1. A device for recovering carbon dioxide from a gaseous medium, comprising:a first air flow channel for the gaseous medium,a second air flow channel for exhaust air from the device,at least one rotatable pre-drying unit, comprising at least one sorbent for the physisorption of water, andat least one drying unit and at least one CO2 unit for adsorbing CO2,wherein the at least one rotatable pre-drying unit is drivable in an axially rotating manner and the first air flow channel flows radially towards the at least one axially rotatable pre-drying unit andwherein the rotatable pre-drying unit comprises at least two sorbents for the physisorption of water.

2. The device according to claim 1, wherein the CO2 unit comprises at least one adsorption module and at least one desorption module.

3. The device according to claim 1 or 2, wherein the drying unit comprises at least four modules, and wherein the modules are at least one desorption module, at least two thermal displacement modules and at least one adsorption module.

4. The device according to any one of claims 1 to 3, wherein the second air flow channel controls the rotatable pre-drying unit axially.

5. The device according to any one of claims 1 to 4, wherein the at least one sorbent comprises zeolite, graphite, aluminosilicate, MOF (Metal Organic Framework) or a silica gel for the physisorption of water.

6. A method for recovering carbon dioxide, comprising the steps of:- providing a gaseous medium in a first air flow channel,- pre-drying the gaseous medium in a rotating pre-drying unit,- drying the pre-dried gaseous medium in at least one drying unit,- adsorbing CO2 from the dried gaseous medium in a CO2 unit andsimultaneously recovering CO2 by desorbing CO2 in a CO2 unit, wherein2025200855   30 Sep 2026the rotating pre-drying unit rotates axially and the first air flow channel flowsradially towards the axially rotating pre-drying unit andwherein the rotatable pre-drying unit comprises at least two sorbents for the physisorption of water.

7. Use of a device according to any one of claims 1 to 5, or of a method according to claim 6 for recovering carbon dioxide from a gaseous medium.

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