Device for the desorption of carbon dioxide

Abstract

The present invention relates to a desorption device for the desorption of carbon dioxide from an adsorption material, the device comprising: a vertical process section having an adsorption material inlet and an adsorption material outlet; a heating device for heating the process section; a vacuum pump, which is arranged in a discharge line, wherein the discharge line branches off from the process section adjacent to the adsorption material inlet and draws carbon dioxide from the process section into the discharge line; a blocking element, which is arranged in the process section adjacent to the adsorption material outlet; and a compressed gas source, which is designed to feed a gas into the vertical process section at a feed means, wherein the feed means is arranged adjacently to the adsorption material outlet between the adsorption material outlet and the blocking element such that gas from the compressed gas source can be guided through the blocking element.

Description

[0001] R.415520

[0002] Description

[0003] title

[0004]

[0005] of carbon dioxide

[0006] State of the art

[0007] The present invention relates to a device for the desorption of carbon dioxide.

[0008] To achieve climate goals, strategies for removing carbon dioxide from the atmosphere are also being discussed. One possible technology is the direct extraction of carbon dioxide from the ambient air, also known as Direct Air Capture (DAC). The extracted carbon dioxide can then be used in other processes or stored underground in caverns. One possibility is to bind the carbon dioxide to an adsorbent such as zeolite or similar materials and then separate the carbon dioxide in a desorption device. For example, US patent 10,279,306 B2 discloses a method for separating carbon dioxide. In this process, an adsorbent material is alternately exposed to carbon dioxide-containing gas and water vapor. However, such a system requires an expensive and complex construction.

[0009] Disclosure of the invention

[0010] The desorption device according to the invention for the desorption of carbon dioxide (CO2) from an adsorption material, in particular a free-flowing one, with the features of claim 1, has the advantage that continuous desorption of CO2 is possible even under difficult conditions. In particular, according to the invention, a continuously operable process section can be provided during the desorption process.

[0011] In particular, a blockage or obstruction in the process path R.415520

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[0013] This must be prevented. Such a blockage or obstruction could completely stop the flow of the adsorption material, especially if the adsorption material has become moist and swells. The adsorption material is a solid, in particular a granular material, e.g., zeolite.

[0014] According to the invention, this is achieved by the desorption device having a process section inclined relative to the horizontal, in particular a vertical section, with an inlet for the adsorption material and an outlet for the adsorption material. Furthermore, the desorption device includes a heating device for heating the process section and a vacuum pump. The vacuum pump is arranged in a discharge line that branches off from the process section, in particular adjacent to the inlet for the adsorption material, and draws material from the process section into the discharge line. The desorption device also includes a shut-off element, which is arranged in the process section, in particular adjacent to the outlet for the adsorption material, and a pressurized gas source. The pressurized gas source is configured to supply gas to the inclined, in particular vertical, process section at a feed point to ensure the free-flowing properties of the adsorption material.The feeder therefore opens into the process section, particularly adjacent to the adsorption material outlet, so that the gas supplied via the feeder from the pressurized gas source flows against the flow direction of the free-flowing adsorption material. The feeder thus opens between the adsorption outlet and the shut-off element. Besides preventing blockages or similar issues, the pressurized gas supplied from the pressurized gas source, which is higher than the pressure in the process section, ensures that a predetermined flow rate can be maintained in the process section towards the adsorption material outlet. The pressure in the process section is defined, in particular, by the vacuum pump and is preferably at ambient pressure. The supplied gas can also be used for additional drying of the adsorption material.

[0015] The dependent claims describe preferred embodiments of the invention.

[0016] Preferably, the shut-off element, in particular a through-opening of the shut-off element, is adjustable. This allows for an R.415520

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[0018] Speed ​​of movement, in particular flow rate or

[0019] The flow rate of the adsorption material, which flows from above from a first reservoir or the like through the process path to a second reservoir, can be adjusted.

[0020] The shut-off element is preferably an adjustable orifice, a valve, or a slide gate. Alternatively, the shut-off element is fixed and non-adjustable, for example, a fixed orifice.

[0021] The desorption device preferably comprises a control unit configured to control a gas flow from the pressurized gas source as a function of a movement speed, in particular the flow rate of the adsorption material in the process section. Thus, if, in particular, an adjustable shut-off element is arranged in the process section, an additional adjustment option for the flow rate of the adsorption material can be provided.

[0022] Preferably, the control unit adjusts the flow rate of the adsorption material in the process section by means of an adjustable valve, which is arranged upstream of the process section in the direction of gas flow from the pressurized gas source.

[0023] Preferably, the control unit is further configured to clear a blockage at the shut-off element by means of a pressure pulse from the pressurized gas source. The control unit can thus briefly increase the pressure to such an extent that the gas flowing in at high pressure from the pressurized gas source clears any obstruction or blockage in the process section.

[0024] Preferably, the pressurized gas source is a nitrogen source. The nitrogen source comprises gaseous nitrogen stored at a higher pressure, for example in cylinders or the like, than the pressure prevailing in the process line. This pressurized gas source can be provided safely and very cost-effectively.

[0025] Preferably, the pressurized gas source includes a carbon dioxide recirculation device. The carbon dioxide recirculation device eliminates the need for a separate pressurized gas source; instead, R.415520

[0026] - 4 -

[0027] Carbon dioxide desorbed from the adsorption material is used as a gas for the pressurized gas source. The carbon dioxide recirculation device comprises a return line that branches off from the discharge line in the direction of flow downstream of the vacuum pump. Preferably, the branch originates from an intermediate carbon dioxide storage tank.

[0028] The desorption device preferably comprises a measuring device for determining the flow velocity, which is configured to detect the flow velocity of the free-flowing adsorption material in the process section. The measuring device is preferably a camera located in the process section or a scale arranged at the end of the process section, which determines the flow velocity based on a weighed quantity of adsorption material passed through. Alternatively, piezoelectric elements or strain gauges arranged at an impact point of the adsorption material after the process section can be provided to detect the quantity of adsorption material passed through.

[0029] The heating device for heating the process section is preferably arranged in a jacket-like shape around the process section.

[0030] Preferably, the process section is designed as a trickle tower, through which the adsorption material trickles solely due to gravity.

[0031] The invention further comprises a carbon dioxide separation device, in particular a direct air capture (DAC) system with an adsorption device and a desorption device of the type described above, which are fluidically connected to each other for the circulation of the adsorption material.

[0032] drawing

[0033] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawing. The drawing shows: R.415520

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[0035] Figure 1 shows a desorption device according to a first embodiment of the invention,

[0036] Figure 2 shows a desorption device according to a second embodiment of the invention and

[0037] Figure 3 shows a desorption device according to a third embodiment of the invention.

[0038] Preferred embodiments of the invention

[0039] A desorption device 1 according to a first preferred embodiment of the invention is described in detail below with reference to Figure 1.

[0040] The desorption device 1 comprises, as shown in Figure 1, a vertical process section 2, which is designed as a vertical trickle tower through which an adsorption material 8 trickles due to gravity. The process section 2 includes an adsorption material inlet 21 and an adsorption material outlet 22 arranged vertically below it.

[0041] Furthermore, the process section 2 can be heated, wherein a heating device 3 in the form of a casing is arranged around the process section 2.

[0042] The desorption device 1 further comprises a vacuum pump 6, which is arranged in a discharge line 7. The discharge line 7 is designed to remove desorbed carbon dioxide from the adsorption material 8. The discharge line 7 branches off from a section of the process line 2 adjacent to the adsorption material inlet 21.

[0043] In process section 2, a shut-off element 4 in the form of an orifice plate is also provided. The orifice plate can be adjustable or non-adjustable with a constant flow cross-section. As can be seen in Figure 1, the shut-off element 4 is arranged in process section 2 adjacent to the adsorption material outlet 22. R.415520

[0044] - 6 -

[0045] The desorption device 1 further comprises a pressurized gas source 5, which is configured to introduce a gas into the vertical process section 2. The gas is supplied via a feeder 50 (arrow G). As can be seen in Figure 1, the feeder 50 opens into the process section 2 between the shut-off element 4 and the adsorption material outlet 22.

[0046] In this embodiment, the pressurized gas source 5 is a nitrogen source 51 from a nitrogen storage device, such as a gas cylinder. A supply line 15 leads from the nitrogen storage device to the feed point 50 in the process section 2. A controllable valve 14 is arranged in the supply line 15. The valve 14 can be controlled by a control unit 10 to open and close.

[0047] The control unit 10 is set up to control a gas flow from the pressurised gas source 5 depending on a flow rate of the adsorption material 8 into the process section.

[0048] Furthermore, the control unit 10 is configured to clear any blockage that may be present at the shut-off element 4 using adsorption material 8. Preferably, the control unit can clear such a blockage at the shut-off element 4 by means of a pressure pulse. For this purpose, the valve 14 can be fully opened so that a high pressure flows into the process section 2 and clears any blockage at the shut-off element 4.

[0049] The control unit 10 also preferentially controls the vacuum pump 6.

[0050] The pressure of the gas in the pressure source 5 is greater than the pressure inside the process section 2, which is very small due to the vacuum pump 6.

[0051] The desorption device 1 comprises a first reservoir 11 in which an adsorption material 8, which has absorbed carbon dioxide, can be stored. The first reservoir 11 is arranged at the upper end of the process section 2 at the adsorption material inlet 21. This allows the adsorption material 8 to trickle through the process section 2 by gravity. At the lower end of the process section 2, a second reservoir 12 is located for receiving R.415520.

[0052] - 7 -

[0053] of the adsorption material 8', from which the carbon dioxide was removed in process section 2.

[0054] During operation of the desorption device 1, the adsorption material 8 is fed into the first reservoir 11, as indicated by arrow A. Due to gravity, the adsorption material 8 flows into the process section 2. The shut-off element 4 determines a flow velocity of the adsorption material 8 through the process section 2. This is indicated by arrows B in Figure 1.

[0055] Furthermore, a vacuum is generated in the process section 2 by means of the vacuum pump 6. The vacuum pump 6 draws in carbon dioxide that has been desorbed in the process section 2. This is indicated by arrows D in Figure 1. A discharge line 7 extends from a branch 70 on the process section 2. The branch 70 is located adjacent to the adsorption material inlet 21. As indicated by arrow E in Figure 1, the carbon dioxide obtained in this way can then be stored, for example, in a storage tank.

[0056] By providing the pressurized gas source 5, a blockage occurring at the shut-off element 4, for example due to moisture causing the adsorption material 8 to swell, can be cleared. This can be achieved by simply opening the valve 14 or by a targeted pressure surge from rapidly opening the valve 14. The operation of the vacuum pump 6 assists in clearing the blockage at the shut-off element 4.

[0057] Furthermore, the adsorption material 8 located in the process section 2 can be loosened by the supply of gas from the pressurized gas source 5. In this case, the valve 14 is constantly open with a predetermined cross-section. The supplied gas from the pressurized gas source 5 can also be used to control the material flow through the process section 2.

[0058] To prevent potential blockages early on, it is also possible to open valve 14 at predetermined intervals, e.g., every minute, to avoid a blockage at the shut-off element 4. R.415520

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[0060] Further preferred embodiments of the invention are described below with reference to Figures 2 and 3, wherein identical or functionally identical parts are designated with the same reference numerals.

[0061] Figure 2 shows a second embodiment of the invention, which essentially corresponds to the first embodiment. In contrast to the first embodiment, in the second embodiment the pressurized gas source 5 includes a carbon dioxide recirculation device 52. For this purpose, a carbon dioxide intermediate storage tank 9 is arranged in the discharge line 7 downstream of the vacuum pump 6. A return line 13 leads from this carbon dioxide intermediate storage tank 9 back to the process section 2. The return line 13 opens at the inlet 50, with a valve 14 arranged upstream of the inlet 50, as in the first embodiment. Thus, a partial flow of the recovered carbon dioxide can be used as the gas for the pressurized gas source and recirculated into the process section 2.

[0062] Figure 3 shows a third embodiment, which essentially corresponds to the second embodiment. In addition, the third embodiment includes a measuring device 16, for example, a camera, arranged in the process section 2. The measuring device 16 is configured to determine the flow velocity of the adsorption material 8 through the process section 2. The measuring device 16 is connected to the control unit 10. Based on the flow velocity of the adsorption material 8 thus determined in the process section 2, the control unit 10 is then configured to actuate the valve 14 and accordingly supply gas to the process section 2, reduce the gas supply, or completely stop it.

Claims

R.415520 - 9 - Claims 1. Desorption device (1) for the desorption of carbon dioxide from an adsorption material (8), in particular a free-flowing one, comprising: - a process section (2) inclined to the horizontal, in particular vertical, with an adsorption material inlet (21) and an adsorption material outlet (22), - a heating device (3) for heating the process section (2), - a vacuum pump (6) which is arranged in a discharge line (7), wherein the discharge line (7) branches off from the process section (2), in particular adjacent to the adsorption material inlet (21), and is further configured to draw carbon dioxide from the process section (2) into the discharge line (7), - a shut-off element (4) which is arranged in the process section (2), in particular adjacent to the adsorption material outlet (22), and - a pressurized gas source (5) which is arranged to supply a gas into the inclined, in particular vertical, process section (2) at a feed (50), wherein the feed (50) is arranged, in particular adjacent to the adsorption material outlet, between the adsorption material outlet (22) and the shut-off element (4), so that gas from the pressurized gas source (5) can pass through the shut-off element (4).

2. Desorption device (1) according to claim 1, wherein the shut-off element (4), in particular a through-opening of the shut-off element (4), is adjustable.

3. Desorption device (1) according to one of the preceding claims, wherein the shut-off element (4) is an orifice or a valve or a slide.

4. Desorption device (1) according to one of the preceding claims, further comprising a control unit (10) configured to control a gas flow from the pressurized gas source (5) depending on a R.415520 - 10 - to control the speed of movement, in particular the flow rate of the adsorption material (8) in the process section (2).

5. Desorption device according to claim 4, wherein the control unit (10) is configured to control the gas flow by means of a valve (14).

6. Desorption device according to claim 4 or 5, wherein the control unit (10) is further configured to release a blockage at the shut-off element (4) by means of a pressure pulse from the pressurized gas source (5).

7. Desorption device according to one of the preceding claims, wherein the pressurised gas source (5) comprises a nitrogen source.

8. Desorption device according to one of claims 1 to 6, wherein the pressurised gas source (5) comprises a carbon dioxide recirculation device (52) which includes a return line (13) between the discharge line (7) and the supply (50).

9. Desorption device according to claim 8, wherein the carbon dioxide recirculation device (52) further comprises a carbon dioxide intermediate storage (9).

10. Desorption device according to one of the preceding claims, further comprising a measuring device (16) which is configured to determine a movement speed, in particular a flow rate of the adsorption material (8) in the process section (2).

11. Desorption device according to claim 10, wherein the measuring device (16) for determining the speed of movement comprises a camera arranged on the process path (2) and / or wherein the measuring device (16) comprises a scale or a piezoelectric element or a strain gauge for determining the weight of material exiting the process path (2).

12. Desorption device according to one of the preceding claims, wherein the process section (2) comprises a trickle tower. R.415520 - 11 - 13. Carbon dioxide separation device comprising an adsorption device and a desorption device according to one of the preceding claims, which are fluidically connected to each other for the circulation of the adsorption material (8).

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