Apparatus and method for extracting co2 from air

Abstract

The invention relates to an apparatus for extracting CO2 from air, the apparatus comprising at least one extraction reactor (12) through which air (L) can flow in an adsorption operating mode, wherein the at least one extraction reactor (12) comprises: at least one CO2 extraction unit (18), through which air (L') can flow in the adsorption operating mode, for adsorbing CO2 contained in the air (L'); and at least one moisture extraction unit (16), through which air (L) can flow in the adsorption operating mode, for adsorbing water contained in the air (L), wherein the at least one moisture extraction unit (16) is arranged upstream of the at least one CO2 extraction unit (18) with respect to an airflow direction in the adsorption operating mode.

Description

[0001] 68676P WO Purem GmbH / 3307 WO - 1 -Device and Method for Extracting CO2 from Air Description The present invention relates to a device and a method for extracting CO2 from air. To prevent an excessive increase in the CO2 content in the Earth's atmosphere, which promotes climate change, extensive measures are being taken to reduce CO2 emissions. However, these measures cannot contribute to lowering the existing CO2 content, i.e., removing CO2 already contained in the Earth's atmosphere. To achieve this, it is known, for example, to generate natural CO2 storage through extensive reforestation or renaturation measures of peatlands. From German patent application DE 102024120259.9, a device for extracting CO2 as an extraction gas from air as a gas mixture in a DAC (Direct Air Capture) process is known.In this device, an extraction reactor comprises a monolithic substrate with a plurality of channel-like cells through which the gas mixture flows. The substrate is coated with an adsorption material providing an adsorption surface. As the gas mixture (air) flows through the cells, the extraction gas (CO2) contained within it is adsorbed onto the adsorption surface during an adsorption phase and thereby extracted from the gas mixture. In a subsequent desorption phase, the substrate, or rather its adsorption surface, is heated to a temperature above the desorption temperature of the extraction gas adsorbed onto the adsorption surface, and the extracted gas released is directed into an extraction gas storage tank. The object of the present invention is to provide a device and a method for extracting CO2 from air with increased efficiency.According to a first aspect of the present invention, this problem is solved by a device for extracting CO2 from air, comprising at least 68676P WO Purem GmbH / 3307 WO. - 2 -An extraction reactor through which air flows during adsorption operation, wherein the at least one extraction reactor comprises at least one CO2 extraction unit through which air flows during adsorption operation for adsorbing CO2 contained in the air and at least one H2O extraction unit through which air flows during adsorption operation for adsorbing water contained in the air, wherein the at least one H2O extraction unit is arranged upstream of the at least one CO2 extraction unit with respect to an air flow direction during adsorption operation. The device constructed according to the invention is structured such that, during adsorption operation, the air providing a gas mixture from which an extraction gas, i.e., CO2, is to be extracted, first flows through the at least one H2O extraction unit and subsequently through the at least one CO2 extraction unit.Since water contained in the air can be essentially completely adsorbed in the at least one H2O extraction unit, dehydrated or essentially anhydrous air leaves the at least one H2O extraction unit and enters the at least one CO2 extraction unit during adsorption operation. Because this essentially prevents water contained in the air from being adsorbed in the at least one CO2 extraction unit, and thus impairs its ability to adsorb CO2, the efficiency with which CO2 can be adsorbed and thus extracted from the air during adsorption operation is significantly increased. It should be noted that the present invention can be used particularly advantageously for the extraction of CO2 (carbon dioxide) from the Earth's atmosphere, i.e., from air. However, the present invention can also be used in conjunction with other CO2-containing gas mixtures.Therefore, air is merely to be considered as an example or placeholder for such CO2-containing gas mixtures. All aspects of the invention presented below can be applied equally to devices or methods with which CO2 is extracted as an extraction gas from other CO2-containing gas mixtures than air. 68676P WO Purem GmbH / 3307 WO. - 3 -Likewise, CO2 as an extraction gas is only to be considered as an example or placeholder for any other gases contained in a gas mixture and to be extracted from it, which can be extracted from the gas mixture by adsorption and subsequently released again by desorption and directed into a suitable storage container. All aspects of the invention described below can be applied equally to devices or processes with which extraction gases other than CO2 are extracted from air or other gas mixtures containing them.In order to convey the air, which is to be freed from an extraction gas, especially CO2, as a gas mixture during adsorption operation, through the at least one reaction reactor, it is proposed that an air conveying device, preferably a blower or compressor, be provided in association with the at least one extraction reactor for conveying air during adsorption operation through the at least one H2O extraction unit and the at least one CO2 extraction unit following the at least one H2O extraction unit in the direction of airflow. For the removal of adsorbed CO2 or...In a desorption operation, a CO2 conveying device, preferably a CO2 discharge pump, can be provided in association with the at least one CO2 extraction unit for conveying CO2 from the at least one CO2 extraction unit to a CO2 storage unit, and an H2O conveying device, preferably an H2O discharge pump, can be provided in association with the at least one H2O extraction unit for conveying water from the at least one H2O extraction unit to an H2O storage unit in a desorption operation. In order to be able to generate independent and thus unmixed volume flows of water and CO2 in the desorption operation, it is proposed that a shut-off valve be provided for selectively interrupting and releasing a flow connection between the at least one CO2 extraction unit and at least one H2O extraction unit.This prevents desorbed water from entering at least one CO2 extraction unit, and68676P WO Purem GmbH / 3307 WO. - 4 -Desorbed CO2 is prevented from entering the at least one H2O extraction unit. For efficient desorption, a CO2 extraction unit heating arrangement can be provided in association with the at least one CO2 extraction unit for heating the at least one CO2 extraction unit to desorb CO2 adsorbed therein during adsorption operation, and an H2O extraction unit heating arrangement can be provided in association with the at least one H2O extraction unit for heating the at least one H2O extraction unit to desorb water adsorbed therein during adsorption operation. In order to avoid intensive thermal interaction with the water or H2O, the heating arrangement is further enhanced by the presence of a heat pump.To achieve CO2 adsorption, it is proposed that at least one CO2 extraction unit comprises at least one CO2 extraction chamber containing CO2 adsorption granules with an adsorption surface for adsorbing CO2-providing CO2 adsorbents, and / or that at least one H2O extraction unit comprises at least one H2O extraction chamber containing H2O adsorption granules with an adsorption surface for adsorbing water-providing H2O adsorbents. For particularly efficient adsorption of CO2 or water, the CO2 adsorbents can be constructed with zeolite material or organometallic material such as MOF CALF-20, and / or the H2O adsorbents can be constructed with silica gel (silica).The use of such a material for the H2O adsorption bodies is particularly advantageous because this material has a comparatively low adsorption capacity for CO2. As an alternative material for such H2O adsorption bodies, alumina (aluminum oxide) can be used. The CO2 extraction unit heating arrangement can comprise at least one electrically excitable heating element located in the CO2 extraction chamber and surrounded by the CO2 adsorption granules. Furthermore, the H2O-68676P WO Purem GmbH / 3307 WO. - 5 -The extraction unit heating arrangement shall comprise at least one electrically excitable heating element located in the H2O extraction chamber and surrounded by the H2O adsorption granules. For enhanced thermal interaction and a resulting improved heating effect during desorption operation, it is proposed that in the CO2 extraction unit heating arrangement and / or in the H2O extraction unit heating arrangement, the at least one electrically excitable heating element shall comprise at least one coiled heating conductor constructed from flat ribbon material.To prevent water contained in the air during adsorption operation from entering the area of ​​the at least one CO2 extraction unit, a sensor arrangement can be provided to supply information representing the water content in the air supplied to the at least one H2O extraction unit during adsorption operation, and / or a sensor arrangement can be provided to supply information representing the water content in the air leaving the at least one H2O extraction unit during adsorption operation.According to a further aspect, the problem mentioned at the outset is solved by a method for extracting CO2 from air by means of a device according to the invention for extracting CO2 from air, comprising the following measures: a) in an adsorption operation, passing air through the at least one H2O extraction unit of the at least one extraction reactor and subsequently through the at least one CO2 extraction unit of the at least one extraction reactor, b) in a desorption operation, desorbing CO2 adsorbed in the at least one CO2 extraction unit and removing the desorbed CO2 from the at least one CO2 extraction unit, and desorbing water adsorbed in the at least one H2O extraction unit and removing the desorbed water from the at least one H2O extraction unit. 68676P WO Purem GmbH / 3307 WO. - 6 -For efficient operation, measures a) and b) can be carried out repeatedly on an alternating basis. To ensure that, during desorption operation, only the materials to be desorbed are directed, for example, towards designated storage areas, it is proposed that, after carrying out measure a) and before the next carrying out measure b), or / and after carrying out measure b) and before the next carrying out measure a), measure c) be carried out to remove residual gas contained in at least one H₂O extraction unit, or / and to remove residual gas contained in at least one CO₂ extraction unit. With repeated alternating execution of measures a) and b), such measure c) can be carried out at each transition from adsorption operation to desorption operation, or / and at each transition from desorption operation to adsorption operation.To easily obtain separate volume flows of the materials to be desorbed, it is proposed that, after carrying out measure a), a flow connection between the at least one H2O extraction unit and the at least one CO2 extraction unit is interrupted, and, upon carrying out measure b), a volume flow of desorbed H2O is directed to an H2O storage unit, and separately, a volume flow of desorbed CO2 is directed to a CO2 storage unit. The two volume flows are thus kept separate from each other within the extraction reactor and do not mix on the flow path from each extraction unit to its respective storage unit.In order to utilize the available adsorption potential as fully as possible, while simultaneously avoiding the introduction of unadsorbed, water-containing air into the at least one CO2 extraction unit, it is proposed that the duration of adsorption operation be determined based on the relative humidity of the air introduced into the at least one H2O extraction unit during adsorption operation. 68676P WO Purem GmbH / 3307 WO. - 7 -Since the material intended for water adsorption becomes saturated more quickly or earlier with increasing relative humidity, i.e., increasing water content in the air, it is proposed that the duration of adsorption operation decrease with increasing relative humidity. Regardless of whether it is already possible to prevent air with a water content that impairs the adsorption potential for CO2 from being introduced into the at least one CO2 extraction chamber by taking the relative humidity into account, it can be provided that the adsorption operation is terminated when the water content of the air exiting the at least one H2O extraction unit during adsorption operation exceeds an associated threshold value. The present invention is described in detail below with reference to the accompanying figures. Figure 1 shows:Figure 1 shows a device for extracting CO2 from air in principle; Figure 2 shows a longitudinal section through an extraction reactor with an H2O extraction unit and a CO2 extraction unit; Figure 3 shows a diagram illustrating the relationship between relative humidity and the time available for adsorption operation; Figure 4 shows a time diagram illustrating a work cycle consisting of adsorption and desorption operation. In Figure 1, a device for extracting CO2 from air is generally designated by 10. The device 10 comprises as its central component an extraction reactor 12, to which, for example, a blower or compressor is applied. 68676P WO Purem GmbH / 3307 WO. - 8 -Air L is supplied as a gas mixture to the air conveying device 14, from which CO2 is to be extracted as the extraction gas. The extraction reactor 12 comprises – with respect to an airflow direction in adsorption operation – an H2O extraction unit 16 and a CO2 extraction unit 18, arranged successively in the direction of flow. A first shut-off valve 20 is arranged upstream of the extraction reactor 12 or upstream of the H2O extraction unit 16, and a second shut-off valve 22 is arranged downstream of the extraction reactor 12 or downstream of the CO2 extraction unit 18. A third shut-off valve 24 is provided in a flow path from the H2O extraction unit 16 to an H2O storage tank 26.Downstream of the third shut-off valve 24, an H2O conveying device 28, for example an H2O drain pump, is provided, through which gaseous medium contained in the H2O extraction unit 16 can be pumped out and conveyed via a directional control valve 30 either to the H2O storage tank 26 or to the environment. A fourth shut-off valve 32 is provided in association with the CO2 extraction unit 28. The fourth shut-off valve 32 is arranged in a flow path from the CO2 extraction unit 18 to a CO2 storage tank 34. Downstream of the fourth shut-off valve 32, a CO2 conveying device, for example a CO2 emptying pump 36, is arranged, through which gaseous medium contained in the CO2 extraction unit 18 can be conveyed via a directional control valve 38 either into the CO2 storage tank 34 or to the environment.A fifth shut-off valve 40 is arranged between the H2O extraction unit 16 and the CO2 extraction unit 18, through which a flow connection between the H2O extraction unit 16 and the CO2 extraction unit 18 can be established or interrupted. All shut-off valves 20, 22, 24, 32, 40, as well as the air conveying device 14, the H2O conveying device 28, the CO2 conveying device 36, and the two directional control valves 30, 38 are controlled by a control unit 42. Depending on the operating conditions, 68676P WO Purem GmbH / 3307 WO. - 9 -The condition of the various conveying devices puts them into operation or takes them out of operation, or sets the various shut-off valves and directional control valves such that the necessary flow connections exist. Fig. 2 shows a more detailed example of the construction of the extraction reactor 12. It should be emphasized that the H2O extraction unit 16 and the CO2 extraction unit are essentially identical in construction, so that the following description is generally applicable to these two extraction units 16, 18. Each of the two extraction units 16, 18 comprises an extraction chamber 44 or 44', which is bounded between two end walls 46, 48 and a circumferential wall, generally designated 50, of a respective extraction unit housing 52 or 52'. The two end walls 46, 48 are permeable to gaseous media. In the extraction chamber 44, a circuit is created by applying an electrical voltage to one or the other end wall 46, 48.Several connecting elements 54 are arranged in a heating element 56, which is excitable and thus heatable and essentially provides a heating arrangement for an H2O extraction unit. In the illustrated embodiment, the heating element 56 comprises a heating conductor 58 made of metallic flat strip material, which is arranged in the extraction chamber 44 such that its narrow sides are oriented towards the two end walls 46, 48, and which is preferably received in the extraction chamber 44 with a winding-like course, for example a meandering or spiral course. The extraction chamber 44 of the H2O extraction arrangement 18 contains an H2O adsorption granulate, generally designated 60. This includes a variety of, for example, spherically shaped H2O adsorption bodies 62, which essentially completely fill the volume of the extraction chamber 44 and provide the heating element 56 for the H2O extraction unit heating arrangement.The heating conductor 58 is essentially completely embedded. Silica gel can be used as the mounting material for the H2O adsorption bodies 62, which exhibits high selectivity for the adsorption of water or water vapor and only requires a certain amount of water. 68676P WO Purem GmbH / 3307 WO. - 10 -exhibits similarly low selectivity for CO2. Alternatively, the H2O adsorption bodies can be constructed with alumina. Likewise, the extraction chamber 44' of the CO2 extraction unit 18 is filled with CO2 adsorption granules 64. The CO2 adsorption granules 64 comprise a multitude of CO2 adsorption bodies 66, for example, with a spherical shape, which essentially completely embed the heating element 56' or the heating conductor 58' provided in the extraction chamber 44' of the CO2 extraction unit 18 and which essentially constitutes a CO2 extraction unit heating arrangement. Zeolite material or a metal-organic material, such as MOF CALF-20, which exhibits high selectivity for the adsorption of CO2, can be used as the construction material for the CO2 adsorption bodies 66.The two extraction units 16, 18, which are essentially identical in construction and differ only in the type of granules used, are assembled in a mirror-image fashion, so that the connecting flanges 68 and 68' provided on the respective extraction unit housings 52 and 52' for connecting the extraction reactor 12 to upstream and downstream system sections, for example the shut-off valves 20, 22, are oriented, and that funnel-shaped tapered housing sections of the respective extraction unit housings 52 and 52' are in contact with the fifth shut-off valve 40, which is designed, for example, in the form of a control flap. In Fig. 2, a flap 70 forming a valve body of the fifth shut-off valve 44 is in an open position in which a flow connection exists between the two extraction units 16, 18.By pivoting the flap 70, this flow connection can be interrupted, so that gaseous media present in the respective extraction units 16, 18 are prevented from flowing into the other extraction unit. In adsorption operation, the two shut-off valves 20, 22 are set to their open position by means of the control unit 42, so that air L conveyed by the air conveying arrangement 14 can flow through the extraction reactor 12. In this process, both water, i.e., gaseous water or water vapor, and 68676P WO Purem GmbH / 3307 WO. - 11 -Air containing CO2 L enters the H2O extraction unit 16, so that water contained in the air L is adsorbed onto the surfaces of the H2O adsorption plates 62. Since the third shut-off valve 24 is in its closed position during adsorption operation, water-depleted air L', or air containing essentially no water or water vapor, leaves the water extraction unit 16 towards the CO2 extraction unit 18. Because water-depleted air L' is conveyed to the CO2 extraction unit 18, there is no risk of water being adsorbed onto the surfaces of the CO2 adsorption plates 66. The entire surface area provided by the CO2 adsorption plates 66 can therefore be used for the adsorption of CO2. Since the fourth shut-off valve 32 is also in its closed position, the water-depleted and CO2-depleted air L'' leaves the extraction reactor 12 via the second shut-off valve 22 and is, for example, expelled to the environment.During the transition from an adsorption operation to a desorption operation, the shut-off valves 20, 22 are first moved to their closed position, the shut-off valves 24, 32 are moved to their open position, and the directional control valves 30, 36 are set so that, in an emptying operation, the residual air still contained in the extraction units 16, 18 is essentially completely extracted from them and released to the surroundings. This process for pumping out residual air or residual gas R or R' from the extraction units 16, 18 can, for example, be carried out for a predetermined duration. Subsequently, a desorption operation is started in which an electrical voltage is applied to the heating elements 56 or 56' of the two extraction reactors 16, 18, and the resulting heating of the H2O adsorption granules 60 or the CO2 adsorption granules 64 is heated to a temperature above the desorption temperature of water or CO2.This results in the release, i.e., desorbed, of adsorbed water in the H2O extraction unit 16. Similarly, adsorbed CO2 is desorbed in the CO2 extraction unit 18. To prevent mixing of these media during desorption operation, the fifth shut-off valve 40 is closed at the end of the adsorption operation. 68676P WO Purem GmbH / 3307 WO. - 12 -The system is brought into operation, in which it interrupts a flow connection between the two extraction units 16, 18. For example, at the start of desorption operation, the directional control valves 30, 38 are positioned so that they establish a flow connection between the H2O conveying device 28 and the H2O storage 26, as well as a flow connection between the CO2 conveying device 36 and the CO2 storage 34. Subsequently, the two conveying devices 28, 36 are put into operation. Water desorbed in the H2O extraction unit 16 is then conveyed into the H2O storage 26, where it can, for example, condense by cooling and be released as water into the environment or used in further processes, for example, for the production of hydrogen.CO2 pumped from the CO2 extraction unit 18 enters the CO2 storage unit 34, where it can be temporarily stored under pressure, for example, to be used subsequently in further processes, such as the production of synthetic fuels or as a feedstock in the chemical industry, or to be permanently stored, for example, in underground storage facilities. The previously described process of adsorbing and desorbing water on the one hand and CO2 on the other can be carried out repeatedly in successive work cycles, whereby, for example, a process for emptying or desorbing is always carried out during a transition from an adsorption operation to a desorption operation, but also during a transition from a desorption operation to a subsequent adsorption operation.Pumping out the gaseous media still contained in the respective extraction reactors can be carried out, in particular to ensure that essentially no water or water vapor enters the area of ​​the CO2 extraction unit 18. In this way, it can be reliably prevented that water, which would impair the subsequent adsorption of CO2, is adsorbed onto the CO2 adsorption bodies 66. Figure 3 illustrates, using curve K1, that the H2O storage capacity of the H2O adsorption granules 60 generally increases with increasing relative humidity. 68676P WO Purem GmbH / 3307 WO. - 13 -The capacity of the air L introduced into the H2O extraction unit 16 increases. Despite this increasing storage capacity for water L contained in the air with increasing relative humidity, the time available in adsorption operation to essentially completely adsorb water contained in the air in the form of water vapor onto the H2O adsorption granules 60, as illustrated by curve K2, decreases with increasing relative humidity. This means that in adsorption operation, with increasing relative humidity, less time is available to ensure that essentially no water flows with the air L' leaving the H2O extraction unit 16 towards the CO2 extraction unit 18 and can be adsorbed onto the surface of the CO2 adsorption granules 64.To take this into account during the repeated alternating execution of adsorption and desorption operations, a sensor arrangement, generally designated 72, is provided in the device 10, for example, upstream of the H2O extraction unit of the extraction reactor 12, and in particular upstream of the H2O adsorption granules 60. The sensor arrangement 72 comprises a sensor whose output signal represents the water content in the air L conveyed to the extraction reactor 10 by the air conveying device 14 and inputs this information or a corresponding sensor signal into the control unit 42. Based on this information, the duration for each adsorption operation within a work cycle comprising one adsorption operation and one desorption operation can be determined during a DAC process.Since the time until water breaks through the H2O extraction unit 16 decreases with increasing relative humidity, the control unit 42 sets the time specified for each adsorption operation such that it decreases with increasing relative humidity, i.e., increasing water content in the air, thus ensuring that an adsorption operation is terminated and a transition to a desorption operation occurs before water breaks through the H2O extraction unit 16. For this purpose, the information generated by the output of the sensor arrangement 72, representing the water content in the air L, can be combined in the control unit 42 with an assigned 68676P WO Purem GmbH / 3307 WO. - 14 -The values ​​are compared to a very low threshold value. If this threshold value is exceeded, the various conveying devices and valves are controlled accordingly to switch from adsorption to desorption operation. Since the desorption rate of water or CO2 in the respective extraction units 16, 18 is generally known from their structural specifications, a defined time interval can be specified for carrying out a desorption operation, or it can be detected using respective sensor arrangements (not shown in the figures) when essentially no more water or CO2 is being released from the extraction units 16, 18, in order to end a desorption operation based on this information and switch to the next adsorption operation.Alternatively or additionally to measuring the relative humidity of the air L introduced into the extraction reactor 12, the water content of the air L' leaving the H2O extraction unit 16 towards the CO2 extraction unit 18 can also be measured by means of a sensor arrangement 74. The sensor arrangement 74 can, for example, be located downstream of the H2O extraction chamber 44 in the area of ​​the H2O extraction unit 16 and upstream of the fifth shut-off valve 40. If the output signal of the sensor arrangement 74 measuring the water content in the air L' indicates that the air L directed towards the CO2 extraction unit 18 has a water content exceeding an assigned threshold value, this can also be used to terminate the adsorption operation and switch to a desorption operation by means of the control unit 42. Fig.Figure 4 shows the development of the CO2 concentration and the H2O concentration for a working cycle comprising one adsorption and one desorption operation. At time T. S The adsorption operation is terminated and, for example, a desorption operation is initiated via an intermediate emptying phase. The CO2 and H2O concentrations in the air L'' leaving extraction reactor 12 during adsorption operation are measured downstream of the CO2-68676P WO Purem GmbH / 3307 WO - 15 -The extraction unit 18, for example, was measured in the area of ​​the second shut-off valve 22. It can be seen that during the entire adsorption operation, essentially no water and no CO2 are contained in the air L'' leaving the extraction reactor 12. During desorption operation, the CO2 and H2O concentrations shown correspond to the total concentration of CO2 and H2O, respectively, contained in the gas streams separately directed to the two storage tanks 26 and 34. It is clearly evident that an increase in the concentrations of CO2 and H2O contained in the total gas stream occurs when the heating elements 56 and 56' are excited.As previously explained, the time TS at which the adsorption operation is terminated can be determined depending on the relative humidity L of the air introduced into the H2O extraction unit 16, in order to ensure that, while preventing water breakthrough towards the CO2 extraction unit 16, the H2O storage capacity of the H2O adsorption granules 60 is essentially fully utilized and, accordingly, a maximum storage quantity of CO2 is achieved in the CO2 extraction unit 18. It is therefore clear that the amount of CO2 adsorbed and thus stored in the CO2 adsorption unit 18 depends on the duration specified for each adsorption operation. The CO2 storage capacity of the CO2 extraction unit 18 should therefore be dimensioned such that even with the maximum possible duration for adsorption operation, the maximum CO2 storage capacity of the CO2 adsorption granules 64 is not exceeded.Finally, it should be noted that the extraction reactor 12 can be structurally varied in a wide variety of ways. For example, a plurality of H2O extraction units 16 can each be provided with an H2O extraction chamber 44 and H2O adsorption granules 60 arranged therein surrounding a heating conductor 58. These H2O extraction units 16 can be connected to each other in parallel or in series with the air L flowing through them. Likewise, several CO2 extraction units 18 can be provided downstream of the fifth shut-off valve 40 in parallel or in series with each other to increase the CO2 storage capacity. 68676P WO Purem GmbH / 3307 WO. - 16 -To increase the speaking capacity. In principle, the device 10 can also provide several extraction reactors 12 and, for example, operate in phase-shifted mode relative to each other, so that at least one of the extraction reactors 12 is always operating in adsorption mode and at least one of the extraction reactors 12 is operating in desorption mode, thus enabling quasi-continuous operation for extracting CO2 from air.

Claims

68676P WO Purem GmbH / 3307 WO - 17 -Claims 1. Device for extracting CO2 from air, comprising at least one extraction reactor (12) through which air (L) flows during adsorption operation, wherein the at least one extraction reactor (12) comprises at least one CO2 extraction unit (18) through which air (L') flows during adsorption operation for adsorbing CO2 contained in the air (L') and at least one H2O extraction unit (16) through which air (L) flows during adsorption operation for adsorbing water contained in the air (L), wherein at least one H2O extraction unit (16) is arranged upstream of the at least one CO2 extraction unit (18) with respect to an airflow direction during adsorption operation. 2.Device according to claim 1, characterized in that an air conveying device (14), preferably a blower or compressor, is provided in association with the at least one extraction reactor (12) for conveying air (L, L', L'') in adsorption operation through the at least one H2O extraction unit (16) and the at least one CO2 extraction unit (18) following the at least one H2O extraction unit (16) in the direction of airflow.Device according to claim 1 or 2, characterized in that a CO2 conveying device (36), preferably a CO2 discharge pump, is provided in association with the at least one CO2 extraction unit (18) for conveying CO2 in a desorption operation from the at least one CO2 extraction unit (18) to a CO2 storage (34), and that an H2O conveying device (28), preferably an H2O discharge pump, is provided in association with the at least one H2O extraction unit (16) for conveying water in a desorption operation from at least one H2O extraction unit (16) to an H2O storage (26).

4. Device according to claim 3, 68676P WO Purem GmbH / 3307 WO. - 18 -characterized in that a shut-off valve (40) is provided for selectively interrupting and releasing a flow connection between the at least one CO2 extraction unit (18) and the at least one H2O extraction unit (16).

5. Device according to one of claims 1-4, characterized in that a CO2 extraction unit heating arrangement is provided in association with the at least one CO2 extraction unit (18) for heating the at least one CO2 extraction unit (18) for desorbing CO2 adsorbed therein in adsorption operation, and that an H2O extraction unit heating arrangement is provided in association with the at least one H2O extraction unit (16) for heating the at least one H2O extraction unit (16) for desorbing water adsorbed therein in adsorption operation. 6.Device according to any one of claims 1-5, characterized in that the at least one CO2 extraction unit (18) comprises at least one CO2 extraction chamber (44') containing CO2 adsorption granules (64) with an adsorption surface for adsorbing CO2-providing CO2 adsorption bodies (66), or / and that the at least one H2O extraction unit (16) comprises at least one H2O extraction chamber (44) containing H2O adsorption granules (60) with an adsorption surface for adsorbing water-providing H2O adsorption bodies (62).

7. Device according to claim 8, characterized in that the CO2 adsorption bodies (66) are composed of zeolite material or organometallic material, or / and that the H2O adsorption bodies (62) are composed of silica gel or alumina. 8.Device according to claim 5 and claim 6 or 7, characterized in that the CO2 extraction unit heating arrangement includes at least one arranged in the CO2 extraction chamber (44') and by 68676P WO Purem GmbH / 3307 WO. - 19 -9. Device according to claim 8, characterized in that, in the CO2 extraction unit heating arrangement and / or in the H2O extraction unit heating arrangement, the at least one electrically excitable heating element (56, 56') comprises at least one heating conductor (58, 58') constructed of flat ribbon material and extending in a coiling manner. 10.Device according to one of claims 1-9, characterized by a sensor arrangement (72) for providing information representing the water content in the air (L) supplied to the at least one H2O extraction unit (16) during adsorption operation, or / and a sensor arrangement (74) for providing information representing the water content in the air (L') leaving the at least one H2O extraction unit (16) during adsorption operation.11.Method for extracting CO2 from air by means of a device for extracting CO2 from air according to any one of claims 1-10, comprising the measures: a) in an adsorption operation, passing air (L, L', L'') through the at least one H2O extraction unit (16) of the at least one extraction reactor (12) and subsequently through the at least one CO2 extraction unit (18) of the at least one extraction reactor (12), b) in a desorption operation, desorbing CO2 adsorbed in the at least one CO2 extraction unit (18) and draining the desorbed CO2 from the at least one CO2 extraction unit (18) and desorbing CO2 in the at least one H2O extraction unit (16) ad-68676P WO Purem GmbH / 3307 WO. - 20 -12. Method according to claim 11, characterized in that measures a) and b) are carried out alternately.

13. Method according to claim 11 or 12, characterized in that after carrying out measure a) and before the next carrying out measure b) or / and after carrying out measure b) and before the next carrying out measure a), a measure c) is carried out to remove residual gas (R) contained in the at least one H2O extraction unit (16) or / and to remove residual gas (R') contained in the at least one CO2 extraction unit (18). 14.Device according to one of claims 11-13, characterized in that, after carrying out measure a), a flow connection between the at least one H2O extraction unit (16) and the at least one CO2 extraction unit (18) is interrupted, and, upon carrying out measure b), a volume flow of desorbed H2O is directed to an H2O storage (26), and separately, a volume flow of desorbed CO2 is directed to a CO2 storage (34).

15. Method according to one of claims 11-14, characterized in that a duration for adsorption operation is determined as a function of the relative humidity of the air (L) introduced into the at least one H2O extraction unit (16) during adsorption operation.

16. Device according to claim 15, characterized in that the duration for adsorption operation decreases with increasing relative humidity. 68676P WO Purem GmbH / 3307 WO. - 21 -17. Method according to one of claims 11-16 characterized in that the adsorption operation is terminated when the water content of the air (L') leaving the at least one H2O extraction unit (16) in the direction of the at least one CO2 extraction unit (18) during adsorption operation exceeds an associated threshold value.

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