Combination of a stationary air drying system with direct air capture

Abstract

The present invention relates to a device for extracting carbon dioxide from a gaseous medium, said device comprising at least one stationary drying unit having at least one air dryer and at least one CO2 unit. The invention also relates to a method for extracting carbon dioxide, as well as to the use of the device and of the method.

Description

[0001] Description

[0002] “Combination of a stationary air drying system with direct air capture”

[0003] The invention relates to a device for obtaining carbon dioxide from a gaseous medium, a method for obtaining carbon dioxide from a gaseous medium, and the use of the device and the method for obtaining carbon dioxide.

[0004] WG2016 / 005226A1, WO2015 / 185434A1, and WG2014 / 170184A1 describe exemplary processes for the recovery of carbon dioxide using a chemisorbent following a temperature-vacuum cycling process. Amine-based chemisorbents are often prone to aging and degradation when the material comes into contact with oxygen at temperatures above approximately 60°C. This can occur during the desorption phase at temperatures around 100°C if countermeasures are not taken, such as creating an inert atmosphere in the system using steam or other gases. These protective measures are complex and expensive. During desorption, steam is introduced to displace the residual oxygen, thus preventing damage to the material through degradation.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 approximately 50 °C.

[0005] WO2022 / 109746A1 describes a process for the recovery of carbon dioxide using physisorbents in polar (cold, dry) regions.

[0006] Knox et al., Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017 ICES-2017-188, discloses the use of physisorbents to separate CO2 from the cabin air of spacecraft and space stations. This study uses a so-called four-bed molecular sieve approach, which involves interconnecting modules for pre-drying the cabin air and for CO2 separation.

[0007] EP1142623A2 discloses a temperature-vacuum cycling process for isolating carbon dioxide from a moist, hot gas mixture. US2010251887A1 describes a method for isolating carbon dioxide from a gas mixture comprising a temperature-swing adsorption step.

[0008] WO2014 / 012966A1 discloses a device for an adsorption-desorption alternating reaction.

[0009] W02021 / 004730A1 discloses the use of a zeolite wheel for the purification of exhaust gases loaded with organic pollutants.

[0010] The object of the present invention is to provide a device for obtaining carbon dioxide from a gaseous medium, as well as a method for obtaining carbon dioxide from a gaseous medium, which at least partially overcomes the above-mentioned disadvantages.

[0011] This object is achieved by the device according to the invention according to claim 1 and the method according to the invention according to claim 11.

[0012] Further advantageous embodiments of the invention emerge from the subclaims and the following description of preferred embodiments of the present invention.

[0013] A device according to the invention for obtaining carbon dioxide from a gaseous medium comprises:

[0014] - at least one stationary drying unit comprising at least one air dryer and

[0015] - at least one CO2 unit.

[0016] The gaseous medium can be the atmosphere, ambient air, exhaust gases (e.g., from industrial plants), gas mixtures, point sources, etc. The gaseous medium includes, among other things, carbon dioxide.

[0017] A device according to the invention has at least one stationary drying unit comprising an air dryer. The air dryer can be a zeolite wheel. A zeolite wheel is a rotatable component comprising zeolite. A zeolite wheel can adsorb a substance, e.g. H2O, in one moving position and desorb the substance again in another moving position. Due to the circular movement of the zeolite wheel, the zeolite wheel can alternate between the moving positions. The drying unit or the air dryer preferably has at least one suitable material by means of which the moisture content can be adjusted. The material can be homogeneously distributed in the drying unit or the air dryer. Alternatively, the material can also be distributed in layers in the drying unit or the air dryer. In particular, when the drying unit or the air dryer is constructed in layers, the drying unit orThe air dryer has a drying gradient. A first layer can therefore lead to initial drying down to a specific moisture content. In the next layer of the drying unit or air dryer, further drying can take place down to a specific moisture content. A drying unit or air dryer can have any number of layers. Ideally, the layers are coordinated with one another.

[0018] In one embodiment, the air dryer comprises at least one layer of zeolite. In another embodiment, the drying material of the air dryer consists of zeolite.

[0019] In one embodiment, the air dryer comprises at least one layer of silica gel and at least one layer of zeolite. A layer of silica gel can be arranged in the inlet area of ​​the air dryer to perform pre-drying. The pre-dried medium can then be passed through a layer of zeolite, where further drying can take place.

[0020] In an alternative embodiment of the air dryer, it comprises at least one layer of silica gel and at least two layers of zeolite. A layer of zeolite, a so-called barrier layer, can be arranged in the inlet area of ​​the air dryer. The barrier layer can serve to remove impurities from the gaseous medium, thus protecting the subsequent layers. At least one layer of silica gel can be arranged on the barrier layer so that the silica gel can carry out an initial drying process. The thus pre-dried medium is then passed through the at least one zeolite layer, allowing further drying of the pre-dried medium to take place.

[0021] The zeolite can be 13X zeolite, 5A zeolite, 4A zeolite, 3A zeolite, etc.

[0022] The stationary drying unit preferably adsorbs 99.0%, more preferably 99.7%, even more preferably 99.9% of the amount of water present in the gaseous medium.

[0023] In one embodiment, the air dryer can cool the gaseous medium to a dew point

[0024] < -30°C, preferably to a dew point < -50°C. The temperature of the dried gaseous medium exiting the air dryer preferably has a temperature in the range between 10°C and 40°C, more preferably in the range between 20°C and 30°C.

[0025] A device according to the invention further comprises at least one CCH unit. A CO2 unit can adsorb a certain amount of carbon dioxide. The CCH unit preferably comprises at least one material that can adsorb carbon dioxide.

[0026] The CC>2 unit preferably adsorbs 80%, more preferably 90%, even more preferably 99% of the amount of carbon dioxide present in the gaseous medium.

[0027] A CCh unit can comprise at least two modules.

[0028] In a further embodiment, the CCh unit comprises at least one adsorption module and at least one desorption module. The CCh unit can also have a module that can alternately serve as an adsorption module and a desorption module. Depending on the process stage, the CCh unit can preferably adsorb CO2 or desorb CO2 and be configured accordingly.

[0029] A device according to the invention can have at least one air filter unit. The at least one air filter unit can be part of the stationary drying unit. An air filter unit is a component by means of which the gaseous medium can be supplied in a suitable form to the further component(s). An air filter unit can, for example, remove contaminants such as particles or components from the gaseous medium. If moist supply air is supplied to the air filter unit, the air filter unit can also, for example, remove moisture from the air and thus dry the air to a specific humidity level.

[0030] In one embodiment, the gaseous medium dried in the air dryer is cooled to a specific temperature in a cooler. For example, the dried gaseous medium can be cooled to a temperature <15°C, preferably <10°C, more preferably <8°C. The thus cooled and dried gaseous medium can be fed to the at least one CCh unit.

[0031] Cooling down (e.g., to -20 to -40 °C) after the air dryer in a cooler would require the use of additional or larger air conditioning units. The cooler can be operated via an ice cistern, thus cooling down the dried gaseous medium.

[0032] The at least one cooler can be part of the stationary drying unit.

[0033] The cooler or ice cistern can meet their energy needs from a heat pump. The energy for the heat pump can be provided by conventional energy sources or supplied by renewable energy sources.

[0034] In one embodiment, a device according to the invention comprises 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 required by external energy sources can be reduced, thus increasing the energy efficiency of the device.

[0035] The heat recovered by the heat exchanger unit can be used, for example, for the desorption of carbon dioxide from the CCh unit.

[0036] 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 generate the energy for desorption in the CCh unit. The cold exhaust air from the heat pump can be used for cooling, for example, in the cooler.

[0037] A device according to the invention can further comprise at least one blower device. The blower can serve 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 forced into the device. If the blower is arranged on the outlet side of the device, the suction created by the blower draws the gaseous medium through the device. Preferably, the at least one blower device is part of the stationary drying unit.

[0038] There may be multiple blower units or just one. For the simplest possible design, you can try to avoid multiple blowers and adjust the airflow distribution using variable throttles, as long as the resulting additional pressure loss is acceptable.

[0039] The at least one CCh unit or the respective module within the CCh unit can comprise at least one physisorbent. A physisorbent is a compound that can bind a substance (e.g., a gas such as carbon dioxide) to itself through physical forces. Ideally, a physisorbent desorbs the adsorbed substance under controlled conditions. This can occur, for example, through the effects of heat, pressure, the addition of other substances with the release of the first adsorbed substance, etc.

[0040] The physisorbents used are preferably robust, age-resistant, and commercially available on a large scale. Compared to chemisorbents, there are generally no signs of aging or degradation within the temperature range used.

[0041] 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).

[0042] Preferably, the CO2 unit or each module has a layered structure of physisorbents.

[0043] The CO2 unit or each module can have a layered or homogeneous structure of physisorbent(s). Preferably, the CO2 unit has a homogeneous structure of physisorbent(s). The physisorbent can be zeolite. The physisorbents can also be a mixture of at least two different zeolites.

[0044] Preferably, the drying is carried out such that the medium emerging from the stationary drying unit has a moisture content of 0.0196% to 0.007% (dew point -40 °C), preferably of 0.007% to 0.0022% (dew point -50 °C), more preferably of 0.0022% to 0.0006% (dew point -60 °C).

[0045] Furthermore, the present invention relates to a process for obtaining carbon dioxide comprising the steps of: - drying a gaseous medium in a stationary air drying unit comprising at least one air dryer,

[0046] - Adsorbing CO2 from the gaseous medium, and

[0047] - Extracting CO2 by desorbing the adsorbed CO2.

[0048] Preferably, a method according to the invention is carried out in a device according to the invention. The features of the device should also be applicable to the method.

[0049] The gaseous medium can be the atmosphere, ambient air, exhaust gases (e.g., from industrial plants), gas mixtures, point sources, etc. The gaseous medium includes, among other things, carbon dioxide.

[0050] A method according to the invention comprises the step of drying a gaseous medium in a stationary air drying unit comprising at least one air dryer. The gaseous medium can thus be dried to a specific moisture content.

[0051] Drying can be achieved using at least one suitable material, by means of which the moisture content can be adjusted. The material can be present as a homogeneous material. Alternatively, the material can also be present in layers. A drying gradient can be present, particularly in layered forms. Thus, a first layer can lead to an initial drying process down to a specific moisture content. Further drying can take place in the subsequent layer down to a specific moisture content. Any number of layers can be present. Ideally, the layers are coordinated with one another.

[0052] The air dryer can be a zeolite wheel. As explained above, the zeolite wheel can adsorb water in one state of motion and desorb water in another state of motion.

[0053] During drying, preferably 99.0%, more preferably 99.7%, even more preferably 99.9% of the amount of water present in the gaseous medium can be adsorbed.

[0054] In one embodiment, a method according to the invention comprises cooling the gaseous medium prior to adsorbing the CO2. Cooling of the gaseous medium can be achieved by a cooler. Alternatively, other components for controlling the temperature of the gaseous medium are also conceivable. For example, this could be an air-water heat exchanger. Cooling preferably takes place in the stationary drying unit.

[0055] The incoming gaseous medium is preferably cooled to a defined temperature. The temperature is preferably <15°C, more preferably <10°C, and even more preferably <6°C. The incoming gaseous medium is preferably cooled to a temperature of 5°C.

[0056] A method according to the invention may further comprise the step of heat recovery, in particular the step of heat recovery by means of a heat exchanger unit. Heat recovery can reduce the energy consumption of a method according to the invention compared to prior art methods, thereby increasing energy efficiency.

[0057] The heat recovered from heat recovery can be used, for example, for the desorption of water from the stationary drying unit and / or CO2 from the CCh unit.

[0058] 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 generate the energy for desorption in the stationary drying unit and / or the CCh unit. The cold exhaust air from the heat pump can be used for cooling, for example, in the cooler.

[0059] 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.

[0060] The blower can serve 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 forced into the device. If the blower is arranged on the outlet side of the device, the suction created by the blower draws the gaseous medium through the device. The blower can be part of the stationary drying unit. 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 releases the CO2 from the unit and can preferably be discharged with a high level of purity.

[0061] The CO2 can preferably be discharged at a purity of >80%, more preferably at a purity of >90%, and even more preferably at a purity of >95%. In some embodiments, the CO2 is discharged at a purity of >99%.

[0062] The desorption of the adsorbed CO2 can be carried out by heating to a temperature of >80°C, preferably >100°C, more preferably >120°C, even more preferably >140°C.

[0063] Furthermore, the present invention relates to the use of a device according to the invention or a method according to the invention for obtaining carbon dioxide from a gaseous medium.

[0064] The resulting carbon dioxide 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 basic chemicals, plastics, e-fuels, etc.

[0065] A device according to the invention or a method according to the invention can be part of a direct air capture (DAC) process.

[0066] Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0067] Fig. 1 schematically shows an embodiment of a device according to the invention,

[0068] Fig. 2 schematically shows an embodiment of a device according to the invention, and Fig. 3 schematically shows an embodiment of a method according to the invention.

[0069] An embodiment of a device 100 according to the invention is shown in Fig. 1. The stationary drying unit 101 has an air filter 104, a blower 105, an air dryer (e.g., a zeolite wheel) 106, a heater 110, which is operated, for example, by an electric heater 111, a blower 109, and a cooler 107, which is operated, for example, by an electric cooling device 108. Humid air 103 is fed to the air filter 104 and, by means of the blower 105, to the air dryer 106. The air dryer 106 preferably has a physisorbent, such as zeolite, which at least partially adsorbs the moisture from the supplied humid air. The air exiting the air dryer 106 has a temperature of 1, which, for example, has a dew point of -60°C and a temperature of 20-30°C. The air with temperature 1 is passed through the cooler 107 and cooled to a temperature of 2 (e.g., 7°C). Air with temperature2 exits the stationary drying unit 101 into the CCh unit 102. The CC>2 unit 102 has several modules, each containing at least one physisorbent capable of adsorbing CO2. A portion of the air exiting the CCh unit 102 exits the device 100, at least in part, as exhaust air 114. A partial flow of the residual air 113 re-enters the stationary drying unit 101 and is guided into the heater 110 by means of a fan 109. The air exiting the heater 110 has a temperature of 3 (e.g., 60-120°C). The air thus heated is preferably used for drying the air dryer 106, and the exiting air exits the stationary drying unit 101 as moist exhaust air 112.If the air dryer 106 is a zeolite wheel, for example, the air dryer 106 can rotate on its own axis, and the side of the zeolite wheel that has absorbed the moisture from the moist supply air 103 can be dried by the air from the heater 110. The CO2 can be desorbed from the CCh unit 102 and thus recovered. The desorption of the CO2 can be achieved, for example, by heating the CCh unit 102.

[0070] Fig. 2 schematically shows an embodiment of a device 200 according to the invention. Temp. 1 (dew point -60°C; temperature 20-30°C), Temp. 2 (temperature 7°C), Temp. 3 (temperature 60-120°C), stationary drying unit 201, CCh unit 202, moist supply air 203, air filtration 204, fan 205, air dryer 206, cooler 207, fan 209, heater 210, heater 211, moist exhaust air 212, regeneration air (partial flow) 213 and exhaust air 214 can correspond to the respective embodiments in Fig. 1. The cooler 207 can be operated by an ice cistern 215 instead of by an air conditioning unit, as in Fig. 1. The energy for the ice cistern 215 can be supplied by a heat pump 216. The energy for operating the heat pump 216 can come from the surplus energy from renewable energy sources 217.

[0071] Fig. 3 schematically shows an embodiment of a method 318 according to the invention. In a first step 319, a gaseous medium is dried in a stationary air drying unit comprising at least one air dryer. In a further step 320, CO2 is adsorbed from the gaseous medium, and in step 321, the CO2 is recovered by desorbing the adsorbed CO2. List of Reference Symbols

[0072] 100, 200 device

[0073] 101 , 201 stationary drying unit

[0074] 102, 202 CCh unit

[0075] 103, 203 Humid supply air

[0076] 104, 204 Air filtration

[0077] 105, 205 blower

[0078] 106, 206 air dryers

[0079] 107, 207 Radiator

[0080] 108 air conditioner

[0081] 109, 209 blower

[0082] 110, 210 heaters

[0083] 111 , 211 heater

[0084] 112, 212 humid exhaust air

[0085] 113, 213 Regeneration air

[0086] 114, 214 exhaust air

[0087] 215 Ice Cistern

[0088] 216 heat pump

[0089] 217 renewable energy sources

[0090] 318 Processes for the production of carbon dioxide

[0091] 319 drying a gaseous medium in a stationary

[0092] Air drying unit comprising at least one air dryer

[0093] 320 adsorbing CO2 from the gaseous medium

[0094] 321 Extraction of CO2 by desorbing the adsorbed CO2

Claims

Patent claims 1. Device (100, 200) for obtaining carbon dioxide from a gaseous medium, comprising: - at least one stationary drying unit (101, 201) comprising at least one air dryer (106, 206) and - at least one CCh unit (102, 202).

2. Device (100, 200) according to claim 1, wherein the air dryer (106, 206) is a zeolite wheel.

3. Device (100, 200) according to claim 1 or 2, wherein the air dryer (106, 206) cools the gaseous medium to a dew point < -30°C, preferably to a dew point < -50°C, conditioned.

4. Device (100, 200) according to at least one of claims 1 to 3, wherein the CO2 unit (102, 202) comprises at least one adsorption module and at least one desorption module.

5. Device (100, 200) according to at least one of claims 1 to 4, wherein the stationary drying unit (101, 201) comprises at least one air filter unit (104, 204).

6. Device (100, 200) according to at least one of claims 1 to 5, wherein the stationary drying unit (101, 201) comprises at least one cooler (107, 207).

7. Device (100, 200) according to at least one of claims 1 to 6, further comprising at least one heat pump (216).

8. Device (100, 200) according to at least one of claims 1 to 7, further comprising at least one blower device (109, 209).

9. Device (100, 200) according to at least one of claims 1 to 8, wherein the at least one CCh unit (102, 202) comprises at least one physisorbent.

10. The device (100, 200) of claim 9, wherein the at least one physisorbent is selected from the group consisting of silica gel, zeolite, aluminosilicate and MOF (Metal Organic Framework).

11. A process for producing carbon dioxide (318), comprising the steps of: - drying a gaseous medium in a stationary air drying unit comprising at least one air dryer (319), - adsorbing CO2 from the gaseous medium (320), and - Extraction of CO2 by desorbing the adsorbed CO2 (321).

12. The method (318) of claim 11, wherein the at least one air dryer is a zeolite wheel.

13. The method (318) according to at least one of claims 10 to 12, further comprising the step of transporting the gaseous medium by means of a blower.

14. The method (318) according to at least one of claims 10 to 13, wherein the desorption of the adsorbed CO2 is carried out by heating.

15. Use of a device according to at least one of claims 1 to 10, or of a process according to at least one of claims 11 to 14 for obtaining carbon dioxide from a gaseous medium.

Images