Device and method for reducing carbon dioxide in an environmental atmosphere

Abstract

Device for reducing carbon dioxide in an environmental atmosphere, comprising means for adsorbing and desorbing carbon dioxide on an adsorption material, in particular a free-flowing and / or pourable material, comprising a reaction chamber (2) which acts at least temporarily as a desorption section (3) and wherein the adsorption material is arranged at least temporarily in the reaction chamber (2), comprising a gas line unit (4) which is fluidly connected or connectable to the reaction chamber (2), in particular the desorption section (3), by means of a gas inlet line (5) and gas outlet line (6), wherein a gas stream (7) can be introduced into the reaction chamber (2) via the gas inlet line (5) and discharged via the gas outlet line (6), wherein the gas stream (7) can be enriched with desorbed carbon dioxide in the reaction chamber (2) and wherein the gas line unit (4) has heating means (9) by which the gas stream (7) can be heated.

Description

Technical field

[0001] The invention relates to a device for reducing carbon dioxide in a gas, in particular air of an environmental atmosphere, and a method for reducing carbon dioxide in a gas, in particular air of an environmental atmosphere, preferably with a system according to the invention. State of the art

[0002] To limit the warming of the Earth's atmosphere, it is already known that the CO2 concentration in the atmosphere, which has increased due to industrialization, must be actively reduced. So-called "Direct Air Capture" (DAC) systems can be used for this purpose. These systems are characterized by the fact that, in a first step, carbon dioxide is actively separated from the ambient air by adsorption onto an adsorbent material. In a second step, the carbon dioxide is removed from the carbon dioxide-enriched adsorbent material in a desorption process, so that the carbon dioxide can subsequently be permanently bound, for example, by injecting it into geological cavities.

[0003] Since the binding of carbon dioxide to the adsorption material depends on pressure, temperature, and concentration, DAC systems typically consist of either multiple chambers with differently set process conditions or a single chamber in which different process conditions are cyclically applied. In particular, the adsorption of carbon dioxide to the adsorption material occurs at a lower temperature than the desorption of carbon dioxide from the adsorption material. To enable desorption at an elevated temperature, the adsorption material must therefore be heated. This is achieved, for example, in WO 21239748 A1 by passing steam over the adsorption material. The desorbed carbon dioxide is then separated from the water by condensation of the steam, and the condensed water is subsequently re-evaporated into steam and passed over the adsorption material.

[0004] A disadvantage of the current state of the art is that, due to the separation of the desorbed carbon dioxide from the flue gas stream, only heat transfer fluids that allow for easy separation from the desorbed carbon dioxide can be used. Furthermore, the separation process, particularly through condensation, is associated with high energy losses and requires additional equipment for cooling the desorbed carbon dioxide and heating the flue gas stream. Disclosure of the invention

[0005] The object of the present invention is therefore to enable a particularly energy-efficient heating of the adsorption material.

[0006] This problem is solved with regard to the device by the features of claim 1. With regard to the method, this problem is solved by the features of claim 9.

[0007] Advantageous embodiments of the device and method according to the invention are the subject of the following description and description of figures, as well as the dependent claims.

[0008] The features described and claimed in relation to the device shall also be deemed to be disclosed and claimable in accordance with the procedure, and vice versa.

[0009] The device for reducing carbon dioxide in a gas, in particular air of an environmental atmosphere, comprises means for adsorbing and desorbing carbon dioxide on an adsorption material, in particular a free-flowing and / or pourable material, and comprises a reaction chamber for at least temporary absorption of the adsorption material, wherein the reaction chamber acts at least temporarily as a desorption section, wherein a gas line unit is included which is fluidly connected or connectable to the reaction chamber, in particular the desorption section, by means of a gas inlet line and a gas outlet line, wherein a gas stream can be introduced into the reaction chamber via the gas inlet line and discharged via the gas outlet line, wherein the gas stream in the reaction chamber can be enriched with desorbed carbon dioxide, and wherein the gas line unit in particular has heating means by which the gas stream can be heated.

[0010] According to the invention, the gas line unit has a side path which branches off from the gas outlet line and leads into the gas inlet line, wherein recirculation means are assigned to the gas line unit, in particular to the side path, by means of which the gas stream enriched with desorbed carbon dioxide can be at least partially recirculated into the reaction space, in particular the desorption section.

[0011] In other words, the carbon dioxide desorbed by the adsorption material is absorbed into the gas stream and recirculated as part of it. This results in reduced energy consumption, particularly because the energy required to regulate the gas stream temperature is reduced. A particularly advantageous aspect is that the initial gas stream only needs to be fully heated once at the beginning of the desorption process. During the desorption process itself, only the energy lost through energy transfer to the adsorption material needs to be supplied back to the gas stream. Furthermore, the heat transfer fluid used in the gas stream can be selected independently of its separability from the desorbed carbon dioxide, allowing the use of nitrogen, for example, as a heat transfer fluid in addition to water vapor.

[0012] A heat exchanger, for example, can be used as the heating medium. Recirculation can be achieved, for example, by a fan or blower. The adsorption material can be, for example, Lewatit VP OC 1065.

[0013] According to a first advantageous embodiment, the gas line unit can include a steam source with which water vapor can be introduced into the gas stream and, via the gas inlet line, into the reaction chamber, in particular the desorption section. It is particularly advantageous for the gas stream to be initially formed from water vapor from the steam source, especially once, at the start of the desorption process, wherein, at least during the ongoing desorption process, the gas stream is fed by the absorption of desorbed carbon dioxide and / or water vapor released by the adsorption material.

[0014] According to a further advantageous embodiment, flow-generating means can be assigned to the reaction chamber such that the adsorption material can be moved through the reaction chamber, in particular the desorption section, in a particle stream. The flow-generating means are preferably designed and arranged such that the particle stream is oriented as a crossflow and / or counterflow to the gas stream. This advantageously homogenizes the heat transfer to the adsorption material and / or creates temperature zones that enable continuous adsorption and desorption of carbon dioxide. Alternatively, it is also possible for the particle stream to be configured as a parallel flow to the gas stream.

[0015] According to a further advantageous embodiment, the heating medium can be configured to transfer a sufficient amount of heat to the gas stream to achieve a temperature of 10 to 150 °C, particularly preferably 15 to 120 °C, and most preferably 20 to 100 °C, in the reaction chamber. A temperature gradient of 20 to 50 °C and 90 to 110 °C is particularly advantageous in the reaction chamber. The desorption process is especially efficient within this temperature range.

[0016] According to a further advantageous embodiment, the gas piping unit may include a branch section, in particular a steam diverter, wherein the gas outlet line is connected via the branch section to the side path and a processing device. The branch section may advantageously separate desorbed carbon dioxide and / or excess water from the gas stream and supply it to the processing device for further processing and, if necessary, separation from the heat transfer fluid.

[0017] According to a further advantageous embodiment, the gas piping unit can include a liquid source, in particular a water injection nozzle, which is arranged between the recirculation media and the heating media, such that an introduced liquid, in particular water, can be vaporized by the heating media. This advantageously allows the amount of water vapor and / or another or alternative heat transfer fluid in the gas stream to be regulated independently of the vapor source, in order to adapt the gas stream, for example, to a specific loading quantity of the adsorption material with carbon dioxide.

[0018] According to a further advantageous embodiment, a conditioning unit may be included which is operatively connected to the reaction chamber, in particular the desorption section, in such a way that a reduction of the oxygen content, in particular inerting of the atmosphere, is possible. This is advantageous because the adsorption material degrades at elevated temperatures and in contact with air and / or oxygen, and this degradation is prevented or at least reduced by the reduction of the oxygen content.

[0019] According to a further advantageous embodiment, the gas piping unit may include control means for controlling the gas flow. The control means are advantageously connected to the gas piping unit, in particular to the branch section and / or the heating elements and / or the steam source and / or the recirculation elements and / or the liquid source. Particularly preferably, the gas flow can be adjusted to a specific loading quantity of the adsorption material with carbon dioxide and / or a specific loading quantity of the reaction chamber with adsorption material. Control measures can include, for example, increasing and / or decreasing the temperature of the gas flow by activating or deactivating the heating elements, as well as increasing and / or decreasing the proportion of heat transfer fluid and / or heat transfer fluid vapor in the gas flow by activating or deactivating the steam source and / or the liquid source and / or the branch section.

[0020] The above-mentioned problem is also solved by a method for reducing carbon dioxide in a gas, in particular air of an environmental atmosphere, in particular by a device according to one of the embodiments described above, comprising the following process steps: - Providing an adsorption material, in particular a free-flowing and / or pourable material, which is designed for the adsorption and desorption of carbon dioxide, in a reaction space which at least temporarily acts as a desorption section, - Heating the gas flow by means of heating elements enclosed within a gas pipeline unit - Introducing a gas flow through a gas inlet pipe encompassed by the gas piping unit - Enriching the gas stream with desorbed carbon dioxide - Diverting the gas flow through a gas outlet pipe encompassed by the gas pipeline unit.

[0021] According to the invention, the gas stream enriched with carbon dioxide is recirculated into the reaction chamber, in particular the desorption section, by means of recirculation means which transfer the gas stream at least partially via a side path of the gas line unit from the gas outlet line to the gas inlet line.

[0022] To avoid unnecessary repetition, reference is made to the device described above regarding the advantageous effects and the advantageous embodiments of the method.

[0023] In summary, the present invention enables the proposal of a method for reducing carbon dioxide in a gas, in particular air from an environmental atmosphere, which provides a particularly energy-efficient heating of the adsorption material.

[0024] According to a first advantageous embodiment of the method, steam can be introduced from a steam source via the gas inlet line into the reaction chamber, in particular the desorption section.

[0025] Particularly advantageously, the gas stream for initiating the desorption process is formed, preferably once, from water vapor from the steam source, wherein at least during the ongoing desorption the gas stream is fed by the absorption of desorbed carbon dioxide and / or water vapor released by the adsorption material.

[0026] According to a further advantageous embodiment of the method, the evaporation of liquid by the heating medium can be provided, wherein a liquid source encompassed by the gas line unit, in particular a water injection nozzle, introduces the liquid into the gas line unit between the heating medium and the recirculating medium. This advantageously allows the amount of water vapor and / or an alternative or additional heat transfer fluid in the gas stream to be regulated independently of the vapor source, in order to adapt the gas stream, for example, to a specific loading quantity of the adsorption material with carbon dioxide.

[0027] According to a further advantageous embodiment, a reduction of the oxygen content in the reaction chamber, particularly the desorption section, can be provided, especially by inerting the atmosphere, through a conditioning unit connected to the reaction chamber. This is advantageous because the adsorption material degrades at elevated temperatures and in contact with air and / or oxygen, and this degradation is prevented or at least reduced by the reduction of the oxygen content.

[0028] The device and method according to the invention are explained below by way of example using purely schematic figures showing exemplary embodiments. Brief description of the drawings Fig. Figure 1 shows a schematic representation of a device for reducing carbon dioxide in an environmental atmosphere according to a first embodiment. Embodiments of the invention

[0029] Identical elements or elements with the same function are marked with the same reference symbols in the figures.

[0030] In the Fig. Figure 1 shows a schematic representation of a device 1 for reducing carbon dioxide from ambient air, comprising a reaction chamber 2. The reaction chamber 2 is configured at least temporarily as a desorption section 3, and advantageously also at least temporarily as an adsorption section. The desorption section 3 and the advantageous adsorption section can be located in one chamber, for example, alternating over time or in different regions of the chamber, or in several chambers. An adsorption material, particularly a free-flowing or pourable material, is arranged at least temporarily in the reaction chamber 2 and in the desorption section 3, and is preferably a macroporous polymer.

[0031] In the embodiment of the Fig. 1. The adsorption material is moved, for example by a flow medium, in a particle stream 13, which is moved continuously from top to bottom or fluidized in a fluidized bed. Alternatively, the adsorption material can also be arranged stationary in the reaction chamber 2 and / or in the desorption section 3 and / or transported between sections of the reaction chamber 2, for example between an adsorption section and a desorption section 3.

[0032] A gas line unit 4 is arranged at the reaction chamber 2, which guides a gas stream 7. The gas stream 7 is advantageously formed by steam supplied from a steam source 12 to initiate the desorption process. Alternatively, the initial gas stream 7 is formed by heat transfer fluid, in particular water, evaporated from a liquid source 10 and by a heating medium 9. The gas stream 7 is introduced into the reaction chamber 2, in particular the desorption section 3, through a gas inlet line 5 and heats the reaction chamber 2, and in particular the adsorption material arranged therein, advantageously such that a temperature gradient is created in the reaction chamber 2 between a temperature of 10 to 50 °C and 90 to 110 °C.This allows for the advantageous creation of different temperature zones, which, for example, can serve as preheating sections to preheat the adsorption material without significant carbon dioxide desorbing, and / or as cooling sections to cool the adsorption material after desorption to enable further carbon dioxide adsorption. Heating the adsorption material causes previously adsorbed carbon dioxide to be desorbed from the adsorption material and absorbed by the gas stream 7. In this embodiment, the gas stream 7 flows countercurrently to the particle stream 13, although a cross-flow or cocurrent configuration is also conceivable. A continuous adsorption and desorption section is particularly preferred within the reaction chamber 2, in which the adsorption material is moved through different temperature zones, and advantageously pressure zones, within the particle stream 13.

[0033] The gas stream 7 enriched with desorbed carbon dioxide is discharged from the reaction chamber 2 and / or the desorption section 3 via a gas discharge line 6. A side path 11 is arranged in the gas line unit 4 such that the carbon dioxide-enriched gas stream 7 is reintroduced into the reaction chamber 2 via the gas inlet line 6 by means of recirculation media 8. The heating media 9 replenish the energy lost by heating the adsorption material in the gas stream 7, thereby achieving energy savings compared to complete vaporization and / or reheating of the gas stream 7.

[0034] The gas piping unit 4 comprises a branch section 14, which is designed in particular as a steam diverter. Through the branch section 14, partially desorbed carbon dioxide and / or excess water from the gas stream 7 can be transferred from the gas piping unit 4 to a treatment device 15.

[0035] The device 1 for reducing carbon dioxide from ambient air advantageously comprises control means for controlling the gas flow 7. The control means are advantageously connected to the gas line unit 4, in particular the branch section 14 and / or the heating elements 9 and / or the steam source 12 and / or the recirculation elements 8 and / or the liquid source 10. This advantageously allows the gas flow 7 to be adapted to a specific loading quantity of the adsorption material with carbon dioxide or a specific loading quantity of the reaction chamber 2 with adsorption material.Control can be achieved, for example, by increasing and / or decreasing the temperature of the gas flow 7 by activating or deactivating the heating medium 9, as well as by increasing and / or decreasing the water and / or water vapor content of the gas flow 7 by activating or deactivating the steam source 12 and / or the liquid source 10 and / or the branch piece 14. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 21239748 A1

[0003]

Claims

[1] Device for reducing carbon dioxide in a gas, in particular air of an environmental atmosphere, comprising means for adsorption and desorption of carbon dioxide on an adsorption material, in particular a free-flowing and / or pourable material, comprising a reaction chamber (2) for at least temporary absorption of the adsorption material, wherein the reaction chamber (2) acts at least temporarily as a desorption section (3), comprising a gas line unit (4) which is fluidly connected or connectable to the reaction chamber (2), in particular the desorption section (3), by means of a gas inlet line (5) and gas outlet line (6), wherein a gas stream (7) can be introduced into the reaction chamber (2) via the gas inlet line (5) and discharged via the gas outlet line (6), wherein the gas stream (7) can be enriched with desorbed carbon dioxide in the reaction chamber (2), and wherein the gas line unit (4) in particular comprises heating means (9) by which the gas stream (7) can be heated. characterized by , that the gas line unit (4) has a side path (11) which branches off from the gas outlet line (6) and leads into the gas inlet line (5), wherein the gas line unit (4), in particular the side path (11), is assigned recirculation means (8) by means of which the gas stream (7) enriched with desorbed carbon dioxide can be at least partially recirculated into the reaction space (2), in particular the desorption section (3). [2] Device according to claim 1, characterized by , that the gas line unit (4) comprises a steam source (12) with which water vapor can be introduced into the gas stream (7) and via the gas inlet line (5) into the reaction chamber (2), in particular the desorption section (3). [3] Device according to one of claims 1 or 2, characterized by, that flow-generating means (11) are assigned to the reaction chamber (2) such that the adsorption material can be moved through the reaction chamber (2), in particular the desorption section (3), in a particle stream (13), wherein the flow-generating means (11) are preferably designed and arranged such that the particle stream (13) is oriented as a cross-flow and / or counter-flow to the gas stream (7). [4] Device according to any one of the preceding claims, characterized by that the heating means (9) are arranged to transfer an amount of heat to the gas stream (7) sufficient to achieve a temperature of 10 to 150 °C, particularly preferably 15 to 120 °C, particularly preferably 20 to 100 °C in the reaction chamber (2). [5] Device according to any one of the preceding claims, characterized by, that the gas piping unit (4) comprises a branch piece (14), in particular a steam diverter, wherein the gas discharge line (6) is connected or connectable through the branch piece (14) to the side path (11) and a processing device (15). [6] Device according to any one of the preceding claims, characterized by , that the gas piping unit (4) comprises a liquid source (10), in particular a water injection nozzle, which is arranged between the recirculation means (8) and the heating means (9), such that an introduced liquid can be evaporated by the heating means (9). [7] Device according to any one of the preceding claims, characterized by , that a conditioning unit is included which is connected to the reaction space (2), in particular the desorption section (3), in such a way that a reduction of an oxygen content, in particular an inerting of the atmosphere, is possible. [8] Device according to any one of the preceding claims, characterized by , that the gas pipeline unit (4) includes control means designed to control the gas flow. [9] A method for reducing carbon dioxide in a gas, in particular air from an environmental atmosphere, in particular with a device according to one of the preceding claims, comprising the following process steps: - Providing an adsorption material, in particular a free-flowing and / or pourable material, which is designed for the adsorption and desorption of carbon dioxide, in a reaction chamber (2) which acts at least temporarily as a desorption section (3); - Heating the gas flow (7) by means of heating medium (9) encompassed by a gas piping unit (4); - Introducing a gas flow (7) through a gas inlet pipe (5) encompassed by the gas piping unit (4); - Enriching the gas stream (7) with desorbed carbon dioxide; - Discharge of the gas flow (7) through a gas discharge line (6) encompassed by the gas line unit (4); characterized by a recirculation of the carbon dioxide-enriched gas stream (7) into the reaction chamber (2), in particular the desorption section (3), by means of recirculation means (8), which transfer the gas stream (7) at least partially via a side path (11) of the gas line unit (4) from the gas outlet line (6) to the gas inlet line (5). [10] Method according to claim 9, characterized by an introduction of water vapor from a steam source (12) via the gas inlet line (5) into the reaction chamber (2), in particular the desorption section (3). [11] Method according to one of claims 9 or 10, characterized byan evaporation of liquid by the heating means (9), wherein a liquid source (10) encompassed by the gas line unit (4), in particular a water injection nozzle, introduces the liquid into the gas line unit (4) between the heating means (9) and the recirculation means (8). [12] Method according to one of claims 10 or 11, characterized by a reduction of the oxygen content, an inerting of the atmosphere, in the reaction chamber (2), in particular the desorption section (3) by a conditioning unit connected to the reaction chamber (2).

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