Co2 separation device for separating co2 from a supplied air flow
Patent Information
- Application Number
- EP2024790856
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-11-03
- Filing Date
- 2024-10-14
- Publication Date
- 2026-09-09
AI Technical Summary
Existing CO2 separation technologies face inefficiencies due to large water vapor capacitors, high energy requirements, and mechanical stress on chamber walls, which increase costs and reduce operational efficiency.
A CO2 separation device with two adjacent separating chambers separated by a common partition, where a section of the CO2 absorption channel runs through the partition and can be cooled from the adjacent separation chamber, allowing for internal passive cooling and efficient separation of CO2 and steam-shaped water.
This approach reduces the size and cost of water vapor capacitors, lowers total energy requirements, and decreases mechanical stress on chamber walls, resulting in a more efficient and cost-effective CO2 separation process.
Smart Images
Figure EP2024078831_08052025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] title
[0003] C02-Abtr for separating CO2 from a
[0004] Airflow
[0005] State of the art
[0006] The invention relates to a CO2 separation device for separating CO2 (carbon dioxide) from a supplied air stream, comprising two adjacent separation chambers which are separated from one another by means of a common partition wall and can be operated in parallel in a CO2 separation mode and a CO2 release mode, and a CO2 discharge channel for selectively discharging separated CO2 and vaporous water from the separation chambers.The invention further relates to a method for separating CO2 from a supplied air stream by means of a CO2 separation device having two adjacently arranged separation chambers which are separated from one another by a common partition wall, wherein one of the two separation chambers is operated in parallel in a CO2 separation mode and the other separation chamber is operated in parallel in a CO2 release mode, and separated CO2 and vaporous water are discharged from the separation chamber in the CO2 release mode by means of a CO2 discharge channel.
[0007] In order to limit the warming of the Earth's atmosphere, so-called DAC systems (Direct Air Capture) are used to separate or remove CO2 (carbon dioxide) from the air.
[0008] Since the binding of CO2 and possibly water (H2O) to an adsorbent material depends on temperature, pressure, concentration, humidity, etc., all adsorption and desorption systems cyclically adjust different conditions to capture CO2 through the resulting hysteresis. To adjust the desorption conditions, the adsorbent material must be temporarily sealed off from the environment and is therefore located in a chamber.
[0009] The chamber usually goes through the following steps cyclically:
[0010] (1) Adsorption of ambient air with the chamber open;
[0011] (2) Closing the chamber and heating the adsorber material and inevitably also the metallic chamber structure;
[0012] (3) Desorption of CO2 and bound water by supplying heat at reduced pressure (e.g. 200 to 400 mbar) and pumping out the CO2 and the vaporous water by means of a vacuum pump;
[0013] (4) Cooling the adsorber material and the chamber and optionally drying the adsorber material to below a critical temperature below which contact with ambient air no longer leads to increased degeneration of the adsorber material by atmospheric oxygen;
[0014] (5) Opening the chamber to the environment, cooling to ambient temperature and thus resuming adsorption of CO2 and water from the ambient air.
[0015] Even cold, dry air contains more water molecules than CO2 molecules, so water is always adsorbed. During desorption in low pressure, approximately three water molecules are released in the form of water vapor for every one molecule of CO2 gas. Thus, three out of four volume fractions are water vapor.
[0016] WO 2020 / 212146 A1 discloses a DAC (Direct Air Capture) system with a containerized solution, with six separation chambers arranged in series and separated by partition walls inside the container. During operation, adsorption phases with an adsorption time of, for example, 5 hours and desorption phases with a desorption time, including heating and cooling, of approximately 1 hour can be carried out cyclically and in a staggered / staggered manner.
[0017] This results in the following disadvantages:
[0018] - Cooling is achieved according to the state of the art using a condenser outside the chamber. This means that the CO2 to be pumped out is passed through a cold trap after leaving the chamber to precipitate as much desorbed water as possible before reaching the vacuum pump. As a result, the pipe cross-section must now be designed for 1 mol CO2 + 3 mol water, which is significantly larger than for 1 mol CO2.
[0019] - In large systems, a vacuum-resistant steam condenser for water is installed upstream of the vacuum pump. This condenser is cooled by cooling water or cold water. The condenser, like the chamber itself, is constructed of corrosion-resistant material, e.g., expensive special stainless steel such as nickel-based steel.
[0020] - Since the chambers are subjected to negative pressure during desorption, the mechanical stress on the chamber surfaces is high, requiring thick chamber walls. These are expensive and heavy and have a high heat capacity, which in turn is disadvantageous because the chamber walls must be heated up during each cycle and cooled down before the next cycle.
[0021] - Since the cyclic process for adsorption can typically take 5 hours, but desorption is very fast and can be shortened to 1 hour with other downtimes, for example in the DAC system according to WO 2020 / 212146 A1 only one chamber is operated in the desorption phase at an elevated temperature of e.g. 100 °C to 110 °C and vacuum, while the other chambers are operated in parallel in the adsorption phase at ambient temperature, e.g. 10 °C on average for Hamburg.
[0022] Disclosure of the invention
[0023] The present invention relates to a CO2 separation device according to independent claim 1, wherein a channel section of the CO2 discharge channel runs through the common partition wall and can be cooled by the separation chamber operated in the CO2 separation mode at the respective time, wherein a channel section inlet of the channel section can be selectively fluidically connected to the separation chamber operated in the CO2 release mode at the respective time in order to separate the vaporous water from the separated CO2 by condensation on the cooled channel section during discharge from the separation chamber.The present invention further relates to a method according to independent claim 12, wherein the separated CO2 and vaporous water are guided during discharge through a channel section of the CO2 discharge channel which runs through the common partition wall and are cooled by the separation chamber operated in the CO2 separation mode in order to separate the vaporous water from the separated CO2 by condensation.
[0024] The approach presented eliminates the disadvantages of the prior art, as "passive" and internal cooling is achieved using the already available cooling energy from the adjacent separation chamber(s). This means that the water vapor condenser upstream of the vacuum pump can be dimensioned much smaller or, if an inexpensive water ring pump is used, can even be eliminated completely. This significantly reduces the investment required for the system hardware, as well as the assembly and piping costs on site. Furthermore, the overall energy requirement for operating the CO2 separation device is much lower, as although energy is released in the condenser during the cooling and condensation of water, this energy must be fed back into the system, e.g., into a separation chamber that needs to be heated, by means of a second heat exchanger.This results in transmission losses in the second heat exchanger, for example, and pumping energy is also required.
[0025] If the adjacent separation chamber is next intended for desorption, the shared partition wall between the two separation chambers heats up because the warm desorption air flow from the separation chamber operating in CO2 desorption mode is guided through the partition wall for at least part of the desorption process time, where water condenses, since the separation chamber operating in CO2 separation mode is still cold or is cooled by the adsorption air flow. Simply put, the wall temperature will adjust to an average temperature between the temperatures of the two separation chambers.On the one hand, part of the separation chamber operated in CO2 desorption mode, namely the wall of the separation chamber operated in CO2 separation mode, has already cooled down somewhat at the end of desorption, so that adsorber degradation is reduced by increased wall temperature, and on the other hand, the wall of the separation chamber operated in CO2 separation mode at the respective time is already preheated, so that the heating requirement for heating is lower.
[0026] It cannot be ruled out that the partition wall or the discharge duct are actively tempered in addition to the pressure, temperature and humidity conditions prevailing in the adjacent separation chambers, e.g. by heating or cooling coils, electrical resistance heating elements or Peltier elements.
[0027] In addition, the modularity of the overall system can be further simplified.
[0028] The CO2 separation device is designed to separate CO2 from a supplied air stream using a separation process. Within the scope of the present invention, the term "separation" encompasses any reasonable method of separating or capturing CO2 (carbon dioxide) from the air, whereby CO2 molecules bind and / or adhere and / or are stored and / or absorbed by a CO2 separation body.
[0029] In this case, the CO2 separation device can be designed, in particular, to separate the CO2 from the supplied air stream using a separation process in which the separation occurs with the release of energy or heat to the air stream. The separation process is preferably a sorption process, in particular an adsorption process and / or an absorption process. Accordingly, the CO2 can be separated, in particular, using at least one of the following processes or combinations thereof:
[0030] - chemical adsorption process
[0031] - physical adsorption process
[0032] - chemical absorption process
[0033] - physical absorption process The CO2 separation device is further designed to release CO2 from the CO2 separation body by means of a release process The term “release” in the context of the present invention includes any sensible type of release or expulsion of CO2 (carbon dioxide) from the CO2 separation body, wherein a solution and / or release and / or release of CO2 molecules from the CO2 separation body takes place.
[0034] In this case, the CO2 separation device is particularly designed to release or dissolve the CO2 from the CO2 separation body by means of a release process in which energy is introduced or
[0035] Heat is introduced into the CO2 separation body and the CO2 is released from it.
[0036] The separation process is preferably a desorption process. Accordingly, the CO2 can be released using at least one of the following processes or combinations thereof:
[0037] - chemical desorption process
[0038] - physical desorption process
[0039] Preferably, the CO2 separation device is designed to perform the separation process and the release process cyclically. In particular, the CO2 separation device is designed to perform the sorption process and the desorption process cyclically. The basic functionality of the CO2 separation device can be analogous, for example, to the aforementioned WO 2020 / 212146 A1.
[0040] The term “supply” or “supplied” in the context of the present invention primarily encompasses an actively carried out or initiated and thus technically controlled or regulated supply of the air flow by means of a blower unit or fan unit of the CO2 separation device. However, the term “supply” or “supplied” can also encompass a passively carried out or initiated supply of the air flow, without thereby departing from the scope of the present invention. Consequently, the air flow can be supplied in any desired manner, for example in a natural manner (as wind). The CO2 separation body is preferably solid. The CO2 separation body can in particular comprise a solid (appropriately functionalized) sorbent, for example a solid adsorbent and / or a solid absorbent. Accordingly, the CO2 separation body can, for example,a fibrous or nonwoven solid as a support structure with a base material selected from the group consisting of: resins, polymers, ceramics, zeolites, silicates, organometallic compounds, organic materials such as cellulose or activated carbon, and combinations thereof. The base material can in turn be specifically functionalized with amines, potassium carbonate, or other components designed to chemically or physically bind CO2.
[0041] An example is the CO2 adsorption / absorption on amine compounds, e.g. Lewatit VP OC 1065, in which CO2 and water initially adhere to molecules and then CO2 forms a strong bond through chemical reaction with the cooperation of water in order to be effective even at low CO2 concentrations.
[0042] The CO2 separation device comprises (at least) two adjacent separation chambers. The two separation chambers are separated from each other by a common partition wall. The common partition wall can, for example, be arranged vertically. The CO2 separation device preferably comprises several separation chambers arranged adjacently in series, each of which is separated from each other by a common partition wall.
[0043] The adjacent separation chambers can be operated in parallel in a CO2 separation mode and a CO2 release mode. In other words, if one of the separation chambers is operating in CO2 separation mode, the other separation chamber can be operated in CO2 release mode, and vice versa.
[0044] The CO2 separation device further comprises a CO2 discharge channel for selectively discharging separated CO2 and water vapor from the separation chambers. In other words, separated CO2 and water vapor can be selectively discharged from a separation chamber currently operating in CO2 release mode via the CO2 discharge channel. Preferably, the CO2 separation mode comprises a CO2 sorption process, and the CO2 release mode comprises a CO2 desorption process.
[0045] The CO2 separation device can comprise a valve unit with a plurality of, in particular controllable, valves for closing the separation chambers for the CO2 release mode. The valve unit can comprise an inlet valve for each separation chamber, which is arranged in an inlet channel for the drawn-in air flow and is configured to close the inlet channel and isolate the respective separation chamber upstream. The valve unit can further comprise an outlet valve for each separation chamber, which is arranged in an outlet channel for the CO2-reduced air flow and is configured to close the outlet channel and isolate the respective separation chamber downstream.The valve unit can also have a CO2 valve (for each separation chamber) which is arranged in the CO2 discharge channel and is designed to open the CO2 discharge channel in order to specifically discharge the separated / bound and released CO2 and the vaporous water from the separation chamber.
[0046] According to the invention, a channel section of the CO2 discharge channel runs through the common partition wall. Due to the adjacent arrangement of the two separation chambers, the channel section can be cooled by the separation chamber currently operating in CO2 separation mode. Furthermore, a channel section inlet of the channel section can be selectively fluidically connected to the separation chamber currently operating in CO2 release mode, in order to separate the vaporous water from the separated CO2 during discharge from the separation chamber by condensation on the cooled channel section.
[0047] The channel section preferably comprises at least two, in particular a plurality of sub-channels, which are arranged in particular parallel to one another. The sub-channels can be arranged or aligned vertically. Advantageously, the common partition wall is designed as a hollow wall in which the channel section or the plurality of sub-channels is arranged. In this case, the hollow wall can have two interconnected corrugated sheet elements or trapezoidal sheet elements, wherein wave crests of one corrugated sheet element are connected to wave troughs of the other corrugated sheet element, or trapezoidal crests of one trapezoidal sheet element are connected to trapezoidal troughs of the other trapezoidal sheet element, in order to form the plurality of sub-channels.
[0048] Furthermore, it is advantageous if the channel section inlet is / are arranged on a bottom side of the CO2 separation device and / or a channel section outlet of the channel section is / are arranged on a top side of the CO2 separation device. In this case, it is particularly advantageous if
[0049] - the channel section inlet has a hollow profile tube which is designed as a cross member, in particular a floor cross member; and / or
[0050] - the duct section outlet has a hollow profile pipe which is designed as a cross member, in particular a roof cross member.
[0051] It is also advantageous if the CO2 separation device comprises a freight container according to ISO 668, in which the separation chambers and the CO2 discharge duct are arranged, or if the container has the dimensions of a freight container according to ISO 668. The CO2 separation device can be designed according to the as yet unpublished DE 10 2023 202 143. In this case, the cross members already present in ISO containers, i.e., the floor cross members and the roof cross members, can be additionally utilized as (air) ducts. Furthermore, the intermediate frames, which are also present, can be used to stabilize the partition wall, making it compressively rigid.
[0052] Advantageously, the channel section inlet of the channel section can be fluidically connected to the separation chambers by means of the valve unit.
[0053] Furthermore, it is advantageous if a water drainage system is provided for the removal, in particular for the collection, of the water condensed in the common partition wall. The collected condensed water can be sprayed into the separation chambers via spray nozzles after optional heating.
[0054] Furthermore, it is advantageous if a cooling unit is provided for additional active cooling of the common partition wall, in particular wherein the active cooling unit has cooling channels and / or cooling elements on and / or in the channel section. The cooling channels and / or cooling elements can be arranged in the sub-channels.
[0055] The CO2 separation device may further comprise at least one of the following units:
[0056] - blower unit, in particular with a plurality of fans for supplying the air flow;
[0057] - Pump unit or vacuum pump for providing an overpressure and / or negative pressure for the release process or desorption process;
[0058] - Steam generator to provide steam for the CO2 release process or desorption process;
[0059] - electric heating unit for additional heating of the separation agent for the release or desorption process;
[0060] - Sensor unit for the separation and release process;
[0061] - Control unit for controlling and / or regulating the separation and release process.
[0062] The control unit can be designed to be connected to other control units and / or a central control unit of the CO2 separation device or a higher-level system by means of radio transmission such as Wi-Fi, Bluetooth, near-field communication, etc.
[0063] The CO2 separation device is preferably designed to be stationary. In particular, the CO2 separation device can be part of a building's air conditioning system, particularly integrated into an air conditioning system within a building. The separation chambers of the CO2 separation device can be integrated into the building's air conditioning circuit. Drawings
[0064] The invention is explained in more detail below with reference to the accompanying drawings. They show:
[0065] Fig. 1 shows a basic structure of a CO2 separation device according to the prior art;
[0066] Fig. 2 a (partially shown) C02-
[0067] separation device;
[0068] Fig. 3 is a sectional view AA of the CO2 separation device from
[0069] Fig. 2; and
[0070] Fig. 4 a sectional view BB of the CO2 separation device from
[0071] Fig. 2.
[0072] In the following description of the prior art and preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of the elements is omitted.
[0073] Fig. 1 shows the basic structure of a CO2 separation device 100 according to the prior art. The CO2 separation device 100 is designed to separate CO2 (carbon dioxide) from an air stream 104 supplied by a blower unit 102 using a cyclic adsorption-desorption process.
[0074] For this purpose, the CO2 separation device 100 has separation chambers 106 (for illustrative purposes, only one is shown here) for accommodating a separation agent or sorbent (not shown). The separation chambers 106 have an inlet valve 108 on an inlet channel 110 for the drawn-in air stream 104, which is designed to close the inlet channel 110 and isolate the separation chambers 106 upstream. The separation chambers 106 further have an outlet valve 112 on an outlet channel 114 for the CO2-reduced air stream 104', which is designed to close the outlet channel 114 and isolate the separation chambers 106 downstream. The separation chambers 106 also have a CO2 valve 116, which is arranged in a CO2 discharge channel 118 and is designed to open the CO2 discharge channel 118 in order to adsorb, ie bound / filtered and desorbed again, iereleased CO2 and vaporous water from the separation chambers 106.
[0075] The separated CO2 and vaporous water are pumped out of the separation chambers 106 by means of a pump unit 120 or vacuum pump 120, wherein a water vapor condenser 122 arranged outside the separation chambers 106 is connected upstream of the vacuum pump.
[0076] The CO2 separation device 100 also has a heating unit 124 for additional heating of the sorbent for the release process or desorption process and a water vapor generator 126 for providing water vapor for the CO2 release process or desorption process.
[0077] Fig. 2 shows (partially) a CO2 separation device 10 according to the invention, which can basically be operated analogously to the CO2 separation device 100 according to Fig. 1.
[0078] The CO2 separation device 10 has adjacent separation chambers 12a, b, which are separated from each other by a common partition wall 14. The separation chambers 12a, b can be operated in parallel in a CO2 separation mode, which includes a CO2 sorption process, and a CO2 release mode, which includes a CO2 desorption process.
[0079] The CO2 separation device 10 further comprises a CO2 discharge channel 16, shown in more detail in Fig. 4, for selectively discharging separated CO2 and water vapor from the separation chambers 12a, b. At the time shown, the separation chamber 12a is operated in the CO2 separation mode, and the separation chamber 12b is operated in the CO2 release mode.
[0080] The CO2 separation device 10 also has a freight container or the dimensions of a freight container according to ISO 668, in which the separation chambers 12a, b and the CO2 discharge channel 16 are arranged.
[0081] As can be seen from the sectional views AA and BB of the CO2 separation device 10 shown in Fig. 3 and Fig. 4, according to the invention a channel section 18 of the CO2 discharge channel 16 runs through the common partition wall 14. The partition wall 14 is surrounded by an intermediate frame of the freight container having a hollow profile-shaped floor support 32, a hollow profile-shaped roof cross member 34 and an intermediate post 36 or is arranged and fastened therein.
[0082] The channel section 18 comprises a plurality of sub-channels 20 arranged vertically and parallel to one another. In the illustrated embodiment, the common partition wall 14 is designed as a hollow wall 14 in which the channel section 18 or the plurality of sub-channels 20 are arranged. The hollow wall 14 comprises two interconnected trapezoidal sheet elements 22a, 22b, with the trapezoidal peaks of one trapezoidal sheet element 22a being connected to the trapezoidal valleys of the other trapezoidal sheet element 22b to form the plurality of sub-channels 20.
[0083] The channel section 18 is cooled by the separation chamber 12a, which is operating in CO2 separation mode at the time shown. The trapezoidal sheet metal element 22a cools, on the one hand, the sub-channels 20 via first cooling sections 24 and, on the other hand, the separation chamber 12b via second cooling section 26. In parallel, the separated CO2 and vaporous water from the separation chamber 12b, which is operating in CO2 release mode at the time shown, are guided through the sub-channels 20 via a channel section inlet 28 of the channel section 18. The channel section inlet 28 is arranged on an underside of the CO2 separation device 10, and analogously, a channel section outlet 30 of the channel section 18 is arranged on an upper side of the CO2 separation device 10. Due to the cooled sub-channels 20, the vaporous water is separated from the separated CO2 by condensation as it is discharged through the channel section 18.The CO2 separation device 10 therefore further comprises a water drainage (not shown) for discharging, in particular for collecting, the condensed water.
[0084] If an embodiment includes an “and / or” link between a first feature and a second feature, this should be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature and according to another embodiment has either only the first feature or only the second feature.
Claims
Claims 1 . CO2 separation device (10) for separating CO2 from a supplied air stream (12), comprising two adjacent separation chambers (12a, b) which are separated from one another by means of a common partition wall (14) and operable in parallel in a CO2 separation mode and a CO2 release mode, and a CO2 discharge channel (16) for selectively discharging separated CO2 and vaporous water from the separation chambers (12a, b), characterized in that a channel section (18) of the CO2 discharge channel (16) extends through the common partition wall (14) and can be cooled by the separation chamber (12a) operated in the CO2 separation mode at the respective time, wherein a channel section inlet (28) of the channel section (18) is selectively fluidically connectable to the separation chamber (12b) operated in the CO2 release mode at the respective time,to separate the vaporous water from the separated CO2 by condensation on the cooled channel section (18) as it is discharged from the separation chamber (12b).
2. CO2 separation device (10) according to claim 1, characterized in that the CO2 separation mode comprises a CO2 sorption process and the CO2 release mode comprises a CO2 desorption process.
3. CO2 separation device (10) according to claim 1 or 2, characterized in that the channel section (18) comprises at least two, in particular a plurality of sub-channels (20), which are arranged in particular parallel to one another.
4. CO2 separation device (10) according to one of the preceding claims, characterized in that the common partition wall (14) is designed as a hollow wall (14) in which the channel section (18) is arranged.
5. CO2 separation device (10) according to claim 4, characterized in that the hollow wall (14) has two interconnected corrugated sheet elements or trapezoidal sheet elements, wherein wave crests of one corrugated sheet element are connected to wave troughs of the other corrugated sheet element or trapezoidal crests of one trapezoidal sheet element are connected to trapezoidal valleys of the other trapezoidal sheet element in order to form the plurality of sub-channels.
6. CO2 separation device (10) according to one of the preceding claims, characterized in that the channel section inlet (28) is / are arranged on a bottom side of the CO2 separation device (10) and / or a channel section outlet (30) of the channel section (18) is / are arranged on a top side of the CO2 separation device (10).
7. CO2 separation device (10) according to claim 6, characterized in that - the channel section inlet (28) has a hollow profile tube (32) which is designed as a cross member (32), in particular a floor cross member (32); and / or - the channel section outlet (30) has a hollow profile tube (34) which is designed as a cross member (34), in particular a roof cross member (34).
8. CO2 separation device (10) according to one of the preceding claims, characterized in that the channel section inlet (28) of the channel section (18) can be fluidically connected selectively to the separation chambers (12a, b) by means of a valve unit.
9. CO2 separation device (10) according to one of the preceding claims, characterized by a water drainage for discharging, in particular further for receiving, the water condensed in the common partition wall (14).
10. CO2 separation device (10) according to one of the preceding Claims, characterized by a cooling unit for additional active cooling of the common partition wall (14), in particular wherein the active cooling unit has cooling channels and / or cooling elements on and / or in the channel section (18).
11. CO2 separation device (10) according to one of the preceding claims, characterized by a freight container according to ISO 668, in which the separation chambers (12a, b) and the CO2 discharge channel (16) are arranged.
12. A method (100) for separating CO2 from a supplied air stream (12) by means of a CO2 separation device (10) with two adjacently arranged separation chambers (12a, b), which are separated from one another by a common partition wall (14), in particular according to one of the preceding claims, wherein one of the two separation chambers (12a) is operated in parallel in a CO2 separation mode and the other separation chamber (12b) is operated in parallel in a CO2 release mode, and separated CO2 and vaporous water are removed from the separation chamber (12b) in the CO2 release mode by means of a CO2 removal channel (16), characterized in that the separated CO2 and vaporous water are guided through a channel section (18) of the CO2 removal channel (16), which runs through the common partition wall (14), and are removed from the CO2 separation chamber operated in the CO2 separation mode. Separation chamber (12a) is cooled,to separate the vaporous water from the separated CO2 by condensation.