Adsorbent material, packed bed filter and method for operating the packed bed filter

Abstract

The invention relates to an adsorbent material (1) for adsorbing carbon dioxide from the atmosphere, comprising a mixture of at least one first substance (A) which is designed to adsorb the carbon dioxide, and at least one second substance (B) which is different from the first substance (A) and which is designed to form a free-flowing or pourable adsorbent material (1) together with the at least one first substance (A).

Description

Technical area

[0001] The invention relates to an adsorbent material for adsorbing carbon dioxide from the atmosphere, which, in particular in connection with a packed bed filter, enables a particularly simple and advantageous operation of the packed bed filter. State of the art

[0002] To limit atmospheric warming, there is discussion about actively reducing the carbon dioxide content in the air, which has increased due to industrialization. So-called "direct air capture" (DAC) systems can be used for this purpose. For example, EP 3 725 391 B1 discloses implementing such a process using a container-like separation unit, which has several absorption chambers containing adsorber material (for the carbon dioxide). Furthermore, EP 2 986 357 B1 discloses adsorber materials that are bonded to fibrous support structures or are designed as fibrous structures for use in such separation devices.

[0003] State-of-the-art solutions for reducing carbon dioxide from the atmosphere using adsorbent materials are characterized by the fact that they are designed for use in stationary systems. This means that when the adsorbent material becomes saturated, the corresponding elements must be exchanged or replaced with the adsorbent material, which is relatively complex.

[0004] In addition, cross-flow packed bed filters are known from the prior art, which are used to purify hot exhaust gas streams. In such a cross-flow packed bed filter, the filter material used for exhaust gas purification, which adsorbs pollutants from the exhaust gas, particularly in the form of loose or pourable limestone, is continuously fed into the system or removed after flowing through it with the exhaust gases. Disclosure of the invention

[0005] Active reduction of the carbon dioxide content of the atmosphere on a large scale requires, in particular, adsorbent materials or technologies that enable relatively cost-effective and simple application on an industrial scale. For example, relatively inexpensive adsorbent materials consisting of particles using ion exchange resins or particles from so-called "metallic-organic frameworks" are known. However, the use of such adsorbent materials is problematic: they tend to stick together and form agglomerates when absorbing water from the air, meaning that the adsorbent materials are no longer flowable or free-flowing. In practice, this prevents their use in the aforementioned packed-bed filters, although the use of these materials in stationary systems is certainly possible.

[0006] In light of the above explanations, the adsorbent material according to the invention for adsorbing carbon dioxide from the atmosphere, with the features of claim 1, has the advantage that it does not tend to stick together even over extended use or during exposure to and flow through with atmospheric air, and remains free-flowing or pourable. This enables, in particular, a continuous or discontinuous exchange of the adsorbent materials in a packed-bed filter, in particular a cross-flow packed-bed filter.

[0007] The adsorbent material according to the invention for adsorbing carbon dioxide from the atmosphere with the features of claim 1 comprises a mixture of at least one first substance which is designed to adsorb the carbon dioxide and at least one second substance which is different from the first substance and which is designed to form a free-flowing or pourable adsorbent material together with the at least one first substance.

[0008] In other words, the second substance assumes the function of keeping the adsorbent material free-flowing or pourable, even if the first substance has absorbed water and / or carbon dioxide. Therefore, the second substance is particularly designed to absorb essentially no water and / or carbon dioxide, or less than the first substance.

[0009] Advantageous further developments of the adsorbent material according to the invention for adsorbing carbon dioxide from the atmosphere are listed in the subclaims.

[0010] In view of the relatively low operating and material costs for the first substance, it is intended that the at least one first substance be a polymeric ion exchange resin. In particular, the use of Lewatit® VP OC 1065 is considered.

[0011] With regard to the at least one second substance for forming an overall free-flowing or pourable adsorbent material, the at least one second substance comprises particulate particles. In particular, these are particles consisting of carbon, such as graphite and / or conductive carbon black, or of molybdenum sulfide, SiC, SiO2, Al2O3, ZrO, or a polymer with a melting point higher than a desorption temperature of the adsorbent material, or mixtures of the aforementioned second substances.

[0012] In a further development of the last proposal, it can be provided that the at least one second substance is designed as a fibrous substance and / or as a zeolite and / or metal-organic framework material.

[0013] In particular, the use of polymeric particles is known to lead to charge separation when flowing through devices or lines, thus resulting in high electrical voltages with the risk of, for example, dust explosions. To counteract this risk, it is particularly preferred that the at least one second material be electrically conductive. This is the case, for example, with second materials consisting of carbon, such as graphite or conductive carbon black.

[0014] There are also different options regarding particle or grain size. In a first variant, the at least one first substance comprises particles with a larger average particle diameter than the at least one second substance, and the mass fraction of the at least one second substance is less than 10% of the total mass of the adsorbent material. In practice, it may even be sufficient to limit the mass fraction of the at least one second substance to less than 1%, as is known, for example, from the use of conductive carbon black in battery electrodes, where the conductive carbon black enables excellent electrical conductivity.

[0015] In an alternative embodiment, however, it is also conceivable for the at least one first substance to have particles with a smaller average particle diameter than the at least one second substance. In this case, the at least one second substance may comprise graphite platelets. Such graphite platelets can advantageously serve as spacers between the relatively small particles of the first substance.

[0016] Furthermore, the invention also comprises a packed bed filter, in particular a cross-flow packed bed filter, with an adsorber material designed according to the invention as described so far.

[0017] Preferably, the packed bed filter is arranged in a system that has a device for the continuous or discontinuous exchange of the adsorbent material. In a preferred design, this device is designed in the form of a conveyor device, in particular a conveyor belt, which feeds the adsorbent material into the system and discharges it from the system after it has been charged. This enables, for example, continuous operation of the packed bed filter without interruptions.

[0018] Finally, the invention also includes a method for operating such a packed bed filter arranged in a system, wherein the method is characterized in that adsorbent material removed from the packed bed filter is fed to a desorption device and subsequently processed in order to be fed back to the packed bed filter. As part of the desorption of the carbon dioxide, the material mixture can be conditioned. Conditioning is to be understood as adjusting the material mixture to the atmospheric conditions (temperature, pressure, humidity, etc.) with energy recovery. Conditioning is also to be understood as checking or measuring the proportions of the at least two different substances via their size, conductivity, flow properties, bulk density, etc. and adjusting them to target values ​​and / or a separation of comminuted and / or degenerated material, e.g.takes place via screening and then the discharged losses are supplemented or compensated.

[0019] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings. Short description of the drawings Fig. 1 shows a simplified representation of a plant for adsorbing carbon dioxide from the atmosphere and Fig. 2 a simplified flow diagram to explain the operation of the system according to Fig. 1. Embodiments of the invention

[0020] The Fig. 1, the system 100 shown in a highly simplified manner serves to remove carbon dioxide from the atmosphere or air. For this purpose, the system 100 has, purely by way of example, a silo-shaped housing 10 which, also purely by way of example, is vertically aligned and anchored to a surface by means of a support structure 12. The housing 10 has an inlet area 14 and an outlet area 16. The ambient air is sucked into the housing 10 via the inlet area 14 by means of a suction fan 18 and passed through a packed bed filter 20 in the form of a cross-flow packed bed filter 22, in order to be released back into the atmosphere or environment via the outlet area 16 after flowing through the cross-flow packed bed filter 22.

[0021] The cross-flow packed bed filter 22 comprises, for example, a continuously rotating conveyor device 24 in the form of a conveyor belt 25 for conveying an adsorbent material 1. The conveyor belt 25 has a strand 26, which is designed, for example, as a perforated strand 26, wherein the diameter or size of the perforations is smaller than the size of the particles of the adsorbent material 1. As a result, the air sucked in by the suction device 18 comes into operative connection or contact with the adsorbent material 1 through the strand 26, which is designed to bind or absorb carbon dioxide present in the air.

[0022] For example, a funnel-shaped storage container 28 for the adsorbent material 1 is provided on the side of the housing 10, through which the adsorbent material 1 reaches directly onto the upper side of the run 26 of the conveyor device 24 to be conveyed into the housing 10 via an opening 30 in the housing 10. Likewise, the housing 10 has a further opening 32 on the side facing away from the opening 30, from which the adsorbent material 1 is dispensed or transferred, for example, into a container 34. The conveyor device 24 conveys the adsorbent material 1 either continuously or discontinuously into the cross-sectional area of ​​the housing 10.

[0023] The adsorbent material 1 for adsorbing carbon dioxide consists of a mixture of at least two substances A, B, wherein the at least one first substance A is designed to absorb carbon dioxide. In contrast, the at least one second substance B serves, together with the first substance A, to form the free-flowing or pourable adsorbent material 1.

[0024] The at least one first substance A consists of a polymeric ion exchange resin, in particular Lewatit® VP OC 1065. This material or ion exchange resin tends to stick together when absorbing water from the air or atmosphere, thus reducing the flowability or pourability of the adsorbent material 1. It is therefore necessary for the at least one second substance B to ensure the flowability or pourability of the adsorbent material 1 even when absorbing water and / or after absorbing the carbon dioxide. The at least one second substance B is in particular a second substance B consisting of particles, in particular consisting of carbon. The carbon can be, for example, graphite and / or conductive carbon black. Alternatively, molybdenum sulfide, SiC, SiO2, Al2O3, ZrO or a polymer with a higher melting point than a desorption temperature of the adsorbent material 1 can be considered.Mixtures of the aforementioned second substances B are also conceivable. The at least one second substance B can be in particulate form, as a fibrous substance, and / or as a zeolite and / or metal-organic framework material. Furthermore, it is preferred that the at least one second substance B be electrically conductive.

[0025] The Fig.The flow diagram shown in Figure 2 serves to explain an advantageous mode of operation of the packed bed filter 20. In a first step 101, the adsorbent material 1 is fed to the system 100. This occurs by discharging the adsorbent material 1 into the storage container 28. Subsequently, in a second step 102, the adsorbent material 1 is conveyed into the cross-section of the housing 10 to absorb the carbon dioxide by means of the conveying device 24. In a third step 103, the adsorbent material 1, at least partially saturated with carbon dioxide, is subsequently discharged into the container 34 by means of the conveying device 24. In a fourth step 104, the adsorbent material 1, saturated or enriched with carbon dioxide, is then fed to a desorption device (not shown). In a fifth step 105, desorption is carried out in the desorption device based on a material analysis of the adsorbent material 1.Subsequently, in a sixth step 106, conditioning of the adsorbent material 1 is carried out. The conditioning in the sixth step 106 particularly also includes an enrichment of substances A and / or B in order to subsequently return the conditioned absorption material 1 to the system 100 for recycling purposes, thus enabling a closed cycle of the adsorbent material 1.

[0026] The adsorbent material 1 described so far or the system 100 can be modified in a variety of ways without deviating from the inventive concept. In particular, it is also conceivable to use a plurality of first and / or second substances A, B. It is only essential that the addition of at least one second substance B ensures the flowability or pourability of the adsorbent material 1 during operation of the system 100. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] EP 3 725 391 B1

[0002] EP 2 986 357 B1

[0002]

Claims

[1] Adsorbent material (1) for adsorbing carbon dioxide from the atmosphere, comprising a mixture of at least one first substance (A) which is designed to adsorb the carbon dioxide, and at least one second substance (B) which is different from the first substance (A) and which is designed to form a free-flowing or pourable adsorbent material (1) together with the at least one first substance (A). [2] Adsorbent material according to claim 1, characterized by that the second substance (B) is designed to absorb no water and / or carbon dioxide or less water and / or carbon dioxide than the first substance (A). [3] Adsorber material according to claim 1 or 2, characterized by that the at least one first substance (A) is a polymeric ion exchange resin, in particular Lewatit® VP OC 1065. [4] Adsorber material according to one of the preceding claims, characterized bythat the at least one second substance (B) comprises particulate particles, in particular consisting of carbon, such as graphite and / or conductive carbon black, or of molybdenum sulfide, SiC, SiO2, Al2O3, ZrO or a polymer with a higher melting point than a desorption temperature of the adsorber material (1), or mixtures of said second substances. [5] Adsorbent material according to one of the preceding claims, characterized by that the at least one second substance (B) is formed as a fibrous substance and / or as a zeolite and / or metal-organic framework material. [6] Adsorber material according to one of the preceding claims, characterized by that the at least one second substance (B) is electrically conductive. [7] Adsorber material according to one of claims 1 to 6, characterized bythat the first substance (A) has particles with a larger average particle diameter than the at least one second substance (B), and that the mass fraction of the at least one second substance (B) is less than 10% of the total mass of the adsorbent material (1). [8] Adsorber material according to one of claims 1 to 6, characterized by that the at least one first substance (A) has particles with a smaller average particle diameter than the at least one second substance (B), and that the at least one second substance (B) has graphite platelets. [9] Packed bed filter (20), in particular cross-flow packed bed filter (22), with an adsorber material (1) designed according to one of claims 1 to 8. [10] Plant (100) with a packed bed filter (20) according to claim 9 and a device for the continuous or discontinuous exchange of the adsorbent material (1) with the packed bed filter (20). [11] System (100) according to claim 10, characterized by that the device is a conveying device (24), in particular a conveyor belt (25), which is designed to feed the adsorber material (1) to the system (100), in particular to the packed bed filter (20), and to discharge it from the system (100) after it has been subjected to pressure. [12] Method for operating a packed bed filter (20) according to claim 10 or 11, characterized by that adsorber material (1) removed from the packed bed filter is fed to a desorption device and then processed in order to be fed again to the packed bed filter (20).

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