Carbon dioxide capture device

Abstract

The carbon dioxide capture device (100) comprises a carbon dioxide adsorbent (101) and a phase change material (102). The phase change material (102) is configured so as to: - store heat generated by the adsorbent (101) during adsorption of carbon dioxide by the adsorbent (101); - release heat to warm the adsorbent (101) so as to enable desorption of carbon dioxide by the adsorbent (101).

Description

Carbon dioxide capture device Technical field of the invention

[0001] The technical field of the invention relates to the adsorption of carbon dioxide. More particularly, the invention relates to a carbon dioxide capture device. Prior art

[0002] Carbon dioxide in the Earth's atmosphere is a greenhouse gas induced by human activities, and it has the particularity of remaining present in the atmosphere for a long time.

[0003] There is a need to reduce the presence of carbon dioxide in the Earth's atmosphere or to reduce its emission caused by human activities. The aim of this reduction is to decrease the carbon footprint of certain activities and / or to contribute to the decarbonization of certain activities and / or to limit the climate impact of industrial activities.

[0004] To this end, it is known to capture carbon dioxide present in the atmosphere or in industrial emissions in order to store or transform it, for example by modifying it to manufacture new products that are currently made from fossil fuels.

[0005] Carbon dioxide capture followed by its storage or transformation allows industries to achieve decarbonization and / or reduce their carbon footprint.

[0006] A process for capturing carbon dioxide using an adsorbent is known. The adsorbent is a material that has the ability to adsorb carbon dioxide and to release, i.e., to desorb, the previously adsorbed carbon dioxide.

[0007] Typically, during adsorption, the adsorbent is subjected to a flow of fluid propagated by forced mechanical ventilation. This mixing reduces the time required for adsorption by forcing transfers between the fluid and the adsorbent. The use of forced mechanical ventilation results in energy consumption, particularly of electricity.

[0008] Desorption is achieved by placing the adsorbent under vacuum at a predetermined absolute pressure while simultaneously heating it with a dedicated heater. This allows the adsorbent to release carbon dioxide, which is then recovered for storage or reuse. The dedicated heater consumes energy, particularly electricity. Alternatively, vacuum sealing is not necessary, but the adsorbent must still be heated sufficiently, which also consumes energy, including electricity.

[0009] The aforementioned energy consumption, particularly of electricity, in addition to having a significant cost, can also be an aggravating factor in carbon dioxide emissions, especially when the electricity required comes from fossil fuels.

[0010] Therefore, there is a need to limit the energy consumption required for carbon dioxide capture. Object of the invention

[0011] The present invention aims to facilitate the capture of carbon dioxide, while limiting the electrical energy consumption for this capture.

[0012] To this end, the invention relates to a carbon dioxide capture device comprising: • a carbon dioxide adsorbent; • a phase-change material; the phase-change material being configured such that: • store heat from the adsorbent during the adsorption of carbon dioxide by the adsorbent; • to release heat to heat the adsorbent in order to allow desorption of carbon dioxide by the adsorbent.

[0013] Such a carbon dioxide capture device makes it possible to prioritize the reduction of energy consumption in electricity during carbon dioxide capture because the supply of calories to allow desorption does not require a means of heating which consumes electrical energy.

[0014] The capture device may also include one or more of the following features.

[0015] According to a feature of the capture device, it comprises beads and the phase-change material is distributed in the beads, with at least some of the beads being in contact with the adsorbent.

[0016] Thus, heat exchange can take place as close as possible to the adsorbent.

[0017] According to a feature of the capture device, the phase-change material is integrated into the mass of the adsorbent. This allows heat exchange to occur as close as possible to the adsorbent.

[0018] According to a feature of the capture device, it includes a reservoir containing the phase-change material, said reservoir being configured to permit heat exchange between the adsorbent and the phase-change material.

[0019] This allows the phase-change material to be contained, while also enabling suitable heat exchange between this material and the adsorbent. The presence of the reservoir ensures better temperature stability within the adsorbent during capture (carbon dioxide adsorption) and regeneration (carbon dioxide desorption).

[0020] According to a feature of the capture device, it includes a tray, said tray comprising a housing in which the adsorbent is arranged at least partly, the housing comprising a bottom delimited at least partly by the reservoir.

[0021] The presence of the tray advantageously allows the adsorbent to be contained while also allowing several carbon dioxide capture devices to be easily stacked.

[0022] According to a characteristic of the capture device, the adsorbent comprises a material chosen from: a metal-organic network (known by the English name "metal-organic framework" (abbreviated as "MOE"), activated carbon, resin, zeolite.

[0023] These materials are perfectly suited to the intended use case.

[0024] According to a characteristic of the capture device, the phase-change material comprises at least one alkane and preferably a mixture of alkanes, also called "paraffin".

[0025] These materials are perfectly suited to the application. In particular, alkanes are the preferred compounds for use as phase-change materials because, depending on temperature and humidity conditions, it is easy to use a mixture of alkanes with a melting point range compatible with the geographical location where the capture device will be used.

[0026] The invention also relates to a carbon dioxide recovery cell, said cell comprising: • a capture assembly comprising at least one carbon dioxide capture device as described; • an enclosure comprising an internal volume suitable for housing the capture assembly, and an opening adapted to allow at least partial passage of the capture assembly through said opening; • a shuttering device configured to adopt a closing configuration in which the shuttering device closes the opening; • a conveyor configured to move the capture assembly between a first position where the capture assembly is in the internal volume and a second position where the capture assembly is at least partly located outside the internal volume; • a vacuum pump configured to reduce the absolute pressure in the chamber.

[0027] Such a recovery cell allows the capture assembly to be positioned either entirely or partially outside the enclosure to allow the adsorption of carbon dioxide, or to be positioned within the enclosure to allow the desorption of carbon dioxide within the enclosure to recover the carbon dioxide or to store the capture assembly in an environment preventing the adsorbent of said at least one capture device from becoming charged with moisture.

[0028] The recovery cell may also include one or more of the following features.

[0029] According to a characteristic of the recovery cell, the conveyor is configured to move the capture assembly in a bidirectional translational motion, preferably substantially horizontal.

[0030] Such a movement is easy to implement while limiting the energy consumption required to achieve it. Indeed, this movement reduces the energy expenditure related to gravity.

[0031] According to a feature of the recovery cell, the capture assembly includes several stacked carbon dioxide capture devices.

[0032] This improves carbon dioxide capture. Furthermore, a stack is easy to move, particularly horizontally, to minimize the energy expenditure due to gravity during this movement.

[0033] According to a feature of the recovery cell, the carbon dioxide capture devices are stacked such that the stack of carbon dioxide capture devices includes at least one passage for a fluid passing through the stack of carbon dioxide capture devices between any two of the carbon dioxide capture devices in that stack, said at least one passage being delimited in part by the adsorbent of one of the carbon dioxide capture devices.

[0034] This passage allows the fluid, such as air, to cooperate with the adsorbent that partially delimits it.

[0035] According to a characteristic of the recovery cell, for each pass, the adsorbents of two adjacent carbon dioxide capture devices within the stack each participate in delimiting a part of said pass.

[0036] This allows for the optimization of exchanges during the passage of the fluid and, where appropriate, it allows for limiting the influence of the fluid on the phase change material by limiting its passage through the stack in regions (i.e. the passages) associated with the adsorbents of two adjacent capture devices.

[0037] The invention also relates to a method for recovering carbon dioxide by a recovery cell as described, this method comprising the following successive steps: a) exposing the capture assembly, at least partially, outside the enclosure in a medium containing carbon dioxide, from which it results: • an adsorption of carbon dioxide by the adsorbent of said at least one carbon dioxide capture device; • heat storage, resulting from adsorption, by the phase change material of said at least one carbon dioxide capture device; b) positioning the capture assembly in its first position and placing the sealing member in its closed configuration; c) acting on the absolute pressure in the enclosure housing the capture assembly by actuation of the vacuum pump to recover carbon dioxide from the adsorbent of said at least one carbon dioxide capture device; the phase change material of said at least one carbon dioxide capture device releasing, during step c), heat to heat the adsorbent of said at least one carbon dioxide capture device.

[0038] Such a process has the advantage of limiting the energy expenditure in electricity during the capture of carbon dioxide by taking advantage of calories accumulated during adsorption to carry out desorption.

[0039] The capture process may include a step of monitoring at least one physical parameter of the medium and a step of choosing an implementation of an adsorption phase or a desorption phase taking into account data from the monitoring step, the adsorption phase consisting of implementing step a), the desorption phase consisting of implementing steps b) and c).

[0040] The capture process can then be controlled precisely to make carbon dioxide capture efficient at opportune times.

[0041] Other advantages and features may emerge from the detailed description that follows. Brief description of the drawings

[0042] The invention will be better understood upon reading the detailed description that follows, given only as a non-limiting example and made with reference to the attached drawings listed below.

[0043] Figure 1 schematically represents a perspective view of a carbon dioxide capture device according to a particular embodiment of the invention.

[0044] Figure 2 shows a cross-sectional view of the capture device of Figure 1.

[0045] Figure 3 schematically represents, in cross-section, a carbon dioxide recovery cell comprising, according to the particular embodiment illustrated, a stack of capture devices as shown in Figure 1. In Figure 3, the recovery cell is in a desorption configuration.

[0046] Figure 4 schematically represents, in cross-section, the recovery cell of Figure 3 but in an adsorption configuration.

[0047] Figure 5 schematically represents a carbon dioxide recovery process using the recovery cell of Figures 3 and 4.

[0048] Figure 6 shows a cross-sectional view of the capture device according to another embodiment.

[0049] Figure 7 schematically represents a side view of a stack of capture devices in a particular arrangement of the latter.

[0050] In these figures, the same references are used to designate the same elements. The elements represented in the different figures are not necessarily drawn to scale in order to facilitate understanding of the figures. Detailed description

[0051] In this detailed description, by substantially horizontal, it is understood to be horizontal or horizontal at plus or minus 10 degrees.

[0052] As illustrated in a particular embodiment in Figures 1 and 2 or in another embodiment in Figure 6, the invention relates to a carbon dioxide capture device 100 (hereinafter referred to as the capture device 100) comprising a carbon dioxide adsorbent 101 and a phase-change material 102. The adsorbent 101 is in particular a solid material.

[0053] The phase-change material 102 is configured such that: • store heat from adsorbent 101 during the adsorption of carbon dioxide by adsorbent 101; • to release heat to heat the adsorbent 101 in order to allow, of course after the adsorbent 101 has adsorbed carbon dioxide, a desorption of carbon dioxide by the adsorbent 101. In other words, the adsorbent 101 and the phase-change material 102 are thermally coupled. The advantage is to limit the consumption of external energy, for example electrical energy, during the desorption of carbon dioxide by utilizing the heat generated by the adsorbent 101 during the adsorption of carbon dioxide.

[0054] The carbon dioxide to be adsorbed by adsorbent 101 is classically in gaseous form.

[0055] Carbon dioxide is also known under stoichiometric conditions under the formulation CO2.

[0056] In order to capture / capture carbon dioxide by the adsorbent 101, it is possible to position the capture device 100 in a medium containing carbon dioxide.

[0057] Any medium containing carbon dioxide and in which the capture device 100 can be exposed can be used. For example, the medium could be: • an atmospheric environment such as the Earth's atmosphere; • a confined space such as an industrial installation emitting carbon dioxide, a chimney, a test bench for an aircraft engine for example.

[0058] In particular, two types of capture are considered: • “point source”, or “at the point source”, where carbon dioxide is captured at the outlet of its emission, for example at the level of the industrial installation, the engine test bench or the chimney (for example, in the case of the engine test bench, the fumes are diluted by air in order to cool the flow sent to the chimney; on the path of these cooled fumes, it is possible to expose the capture device 100 which will capture the carbon dioxide; the phase change material 102 will be chosen for its melting temperature compatible with the temperature of the fumes); • “DAC” (short for “Direct Air Capture”) where capture is achieved by simply exposing the capture device 100 to the Earth’s atmosphere.

[0059] The captured carbon dioxide can then be used to produce methane (CH4).

[0060] The adsorbent 101 may comprise a material, called the "adsorbent material," chosen from: a MOF (short for "Metal-Organic Frameworks"), activated carbon, a resin, or a zeolite. The resin is preferably a weakly basic anionic resin.

[0061] The document "Polycrystalline metal-organic framework (MOF) membranes for molecular separations: Engineering prospects and challenges" by Mohamad Rezi Abdul Hamid et al., published in Journal of Membrane Science 640 (2021) 119802, describes MOFs that can be used to achieve carbon dioxide adsorption in order to capture it.

[0062] The paper "Process-performance of solid sorbents for Direct Air Capture (DAC) of CO2 in optimized temperature-vacuum swing adsorption (TVS A) cycles" by Bhubesh Murugappan Balasubramaniam et al., published in Chemical Engineering Journal 485 (2024) 149568, describes known carbon dioxide adsorbents for DAC that can be used by people skilled in the art.

[0063] For example, adsorbent 101 may include activated carbon pellets impregnated with said adsorbent material, thus forming granules.

[0064] Due to its nature, phase-change material 102 can vary between two physical states such as a solid state and a liquid state.

[0065] The phase-change material 102 is suitable for heat transfer via latent heat, meaning that the phase-change material 102 can absorb or release energy through a change of state. Indeed, during the adsorption phase by the adsorbent 101, the heat of adsorption will be absorbed by the phase-change material 102, which may, if necessary, transition from a solid to a liquid state (storing its latent heat of fusion). During the regeneration phase (desorption by the adsorbent 101), this latent heat of fusion will be released to the adsorbent 101, if necessary during the transition of the phase-change material 102 from a liquid to a solid state.

[0066] The phase-change material 102 may include at least one alkane (also called paraffin). Preferably, the phase-change material 102 may include a mixture of alkanes to extend the operating temperature range of the capture device 100, taking into account the melting points of these alkanes. The alkane(s) comprising the phase-change material 102 may be selected from the table below (the "Name" column gives the names of the different alkanes). The melting temperatures given in the table above are given at atmospheric pressure. For example, when the phase change material 102 comprises an iso-proportional mixture of C14H30, C15H32, C16H34 and C18H12, this covers most situations: this mixture will be preferred for forming the phase change material 102 because it allows good adaptation for a fairly wide target temperature range.

[0067] Of course, a person skilled in the art will be able to choose the appropriate combination of adsorbent 101 and phase-change material 102 according to the desired application, in particular taking into account the environment to be used containing carbon dioxide; the aim being that the adsorption by the adsorbent 101 generates enough heat to be stored within the phase-change material 102 for later release to help / allow the desorption of carbon dioxide from the adsorbent 101. Thus, historical temperature data from the location of use of the capture device 100 can be used to size the capture device 100.

[0068] The capture device 100 may include a plate 105. This plate 105 includes a housing 106 in which the adsorbent 101 is arranged at least in part, and preferably in whole.

[0069] As mentioned above, the phase-change material 102 can vary between two physical states, such as a solid and a liquid state. Therefore, there is a need to contain the phase-change material 102, regardless of its state, while ensuring efficient thermal coupling between this phase-change material 102 and the adsorbent 101.

[0070] For this purpose, the capture device 100 may include a reservoir 103 containing the phase-change material 102. This reservoir 103 is configured to allow heat exchange between the adsorbent 101 and the phase-change material 102. In other words, the reservoir 103 is advantageously thermally coupled to the adsorbent 101 and, in particular, to the phase-change material 102.

[0071] To ensure thermal coupling between the adsorbent 101 and the reservoir 103, and therefore between the adsorbent 101 and the phase change material 102, the adsorbent 101 and the reservoir 103 can be in simple contact, for example, to promote air circulation around the adsorbent 101, just as the phase change material 102 will be in contact with the reservoir 103 in its internal volume.

[0072] The reservoir 103 is preferably made of a thermally conductive material having a thermal conductivity satisfactory for the application. For example, the reservoir 103 includes a wall 104 (Figure 2) made of the thermally conductive material separating, preferably at least locally, the adsorbent 101 from the phase-change material 102, both of which are in contact with this wall 104.

[0073] For example, the tank 103 can be made from a sheet of metal suitable for thermal conductivity. For instance, the tank 103 can be made of aluminum or steel, particularly low-alloy steel, which is preferred for its ideal thermal conductivity and ease of processing (bending / welding). The tank 103 is preferably sealed to prevent any leakage of the phase-change material 102 and thus to contain it within the internal volume of the tank 103.

[0074] It is retained that the use of a reservoir 103 beyond the exact quantity required is preferred (the phase-change material 102 will therefore preferentially be in excess to promote the recovery of thermal energy and its restitution), particularly when the phase-change material 102 is multi-compound (for example, according to the aforementioned mixture). Heat transfer to or from the adsorbent 101 is then enhanced by the large quantity of phase-change material 102 used, especially considering that phase-change materials 102 are inexpensive.

[0075] According to a particular embodiment, the adsorbent 101 can be arranged at least partially in the housing 106. Therefore, the housing 106 includes a base 107 delimited at least partially by the reservoir 103, and in particular by the wall 104 of the reservoir 103. In particular, the tray 105 includes the reservoir 103.

[0076] For example, as illustrated in Figures 1 and 2, the reservoir 103 has / includes on one external face a recess forming said housing 106 in which the entirety of the adsorbent 101 is placed (the adsorbent 101 is contained within the volume of the recess). Alternatively, the adsorbent 101 may, in part, protrude from the volume of the recess.

[0077] An embodiment in which the capture device 100 comprises the reservoir 103 containing the phase-change material 102 has been described above. According to another embodiment, an example of which is illustrated in Figure 6, the capture device 100 may comprise beads 108, and the phase-change material 102 is distributed among the beads 108, with at least some of the beads 108, and in particular each bead 108 as shown in Figure 6, being in contact with the adsorbent 101.

[0078] Preferably, the beads 108 can be distributed throughout the mass of the adsorbent 101. For this purpose, the adsorbent 101 can be formed on the beads 108, for example by gluing to their surface, so as to form a shell around the beads 108. This allows for optimization of the heat exchange between the phase-change material 102 and the adsorbent 101 at the level of each bead 108.

[0079] In fact, each bead 108 forms a closed, so-called "plastic" envelope because it allows the phase-change material 102 to be shaped regardless of whether it is in a solid or liquid state. Thus, the beads 108 prevent the phase-change material 102 from flowing out of the envelopes they form. The material of the beads 108 will, of course, be suitable for its function of conducting heat. For example, the material of the beads 108 could be a plastic, such as polyethylene or polypropylene.

[0080] Thus, it is understood that the 108 balls are hollow and each form a reservoir for a corresponding portion of the phase-change material 102.

[0081] If necessary, the capture device 100 may include the tray 105 comprising the housing 106 in which the adsorbent 101 is arranged, at least in part, in contact with at least a portion of the beads 108 (Figure 6). It is understood here that the tray 105 does not include the reservoir 103 described above.

[0082] It follows from what has been described above that, in general, the phase-change material 102 can be included / integrated into the mass of the adsorbent 101.

[0083] The capture device 100 may include a holding element 109 configured to retain the adsorbent 101 within the capture device 100 (visible, for example, in Figure 6). The retaining element 109 is configured to allow ambient air, including carbon dioxide, to pass through it. Since the adsorbent 101 can be in the form of granules, as mentioned above, also more generally referred to as independent parts of the adsorbent 101, the retaining element 109 prevents the loss of these granules depending on the orientation of the capture device 100 during use. The retaining element 109 may include mesh and be in the form of a wire mesh or a net. In the example illustrated in Figure 6, the retaining element 109 covers the housing 106 and is fixed to its periphery to retain the adsorbent 101 within the housing 106.

[0084] Thus, the mesh can be sized to prevent the passage of granules.

[0085] Although the retaining element 109 is shown only in Figure 6, the capture device 100 in Figures 1 and 2 may just as well include such a retaining element 109.

[0086] Of course, after exposing the adsorbent 101 to the medium containing carbon dioxide, the adsorbed carbon dioxide can be recovered, in whole or in part, in a carbon dioxide recovery cell 1000, also called a desorption cell, a particular embodiment of which is illustrated in Figures 3 and 4. Such a cell 1000 includes a capture assembly 1001 comprising at least one carbon dioxide capture device 100 as described. Preferably, the capture assembly 1001 comprises several capture devices 100 in order to optimize the amount of carbon dioxide captured when the capture assembly 1001 is subjected to the environment.

[0087] The recovery cell 1000 further comprises an enclosure 1002 having an internal volume 1003 suitable for housing the capture assembly 1001. The enclosure 1002 includes an opening 1004 adapted for at least partial passage of the assembly 1001 of capture, and possibly of its entirety, through said opening 1004. Thus, via the opening 1004, the adsorbent 101 of said at least one capture device 100 can be exposed to the medium.

[0088] In order to close the enclosure 1002, in particular in a hermetic manner against air or the environment outside the enclosure 1002, the recovery cell 1000 includes a shuttering element 1005 configured to adopt a closure configuration in which the shuttering element 1005 closes / shuts the opening 1004.

[0089] In particular, the capture assembly 1001 is positioned in the internal volume 1003 of the enclosure 1002 when the closure element 1005 is in its closed configuration in order to implement a desorption of carbon dioxide from the adsorbent 101 of said at least one capture device 100.

[0090] Of course, the shuttering organ 1005 can selectively adopt its closed configuration or an open configuration, the open configuration allowing the capture assembly 1001 to pass at least partially through the opening 1004.

[0091] For example, Figure 3 represents the capture assembly 1001 positioned in the enclosure 1002 with the sealing element 1005 in its closed configuration allowing a desorption phase of the adsorbent 101 to be carried out by said at least one capture device 100.

[0092] For example, Figure 4 represents the capture assembly 1001 positioned outside the enclosure 1002 with the sealing element 1005 in its open configuration allowing an adsorption phase to be carried out by the adsorbent 101 of said at least one capture device 100.

[0093] The 1005 sealing element is, for example, a door.

[0094] In particular, the sealing element 1005 and the enclosure 1002 can cooperate in the closing configuration to ensure a hermetic closure of the enclosure 1002 at its opening 1004. For this purpose, the sealing element 1005 can include an annular seal bearing on the enclosure 1002 at the periphery of the opening 1004 in the closing configuration of the sealing element 1005, conversely the seal can belong to the enclosure 1002 and be arranged at the periphery of the opening 1004.

[0095] In order to expose the adsorbent 101 of said at least one capture device 100 to the middle, there is a need to move the capture assembly 1001 so as to position it at least partly outside the internal volume 1003 of the enclosure 1002, and possibly entirely outside the internal volume 1003 of the enclosure 1002. To satisfy this need, the recovery cell 1000 includes a conveyor 1006 configured to move the capture assembly 1001 between a first position where the capture assembly 1001 is in the internal volume 1003 of the enclosure 1002 (Figure 3) and a second position where the capture assembly 1001 is at least partly (and possibly entirely) located / positioned outside the internal volume 1003 of the enclosure 1002 (Figure 4).

[0096] In particular, the passage from one of the first and second positions to the other of the first and second positions is accompanied by a passage of the capture assembly 1001 through the opening 1004 either partially or totally.

[0097] In general, the recovery cell 1000 includes a vacuum pump 1007 configured to reduce the absolute pressure in the enclosure 1002 to a value that allows the carbon dioxide to be recovered from the adsorbent 101 of said at least one capture device 100. For example, said value is less than or equal to 0.1 mbar in absolute pressure.

[0098] The 1007 vacuum pump can be connected to means of storing the recovered carbon dioxide (not shown).

[0099] Specifically, after the capture assembly 1001 has been subjected to the medium, the adsorbent 101 of said at least one capture device 100 comprises carbon dioxide to be recovered by desorption. Desorption can be carried out when the capture assembly 1001 is positioned in the internal volume 1003 of the enclosure 1002 and the sealing element 1005 is in its closed configuration: the vacuum pump 1007 is then activated so as to reduce the absolute pressure in the enclosure 1002, which has the effect, by using the latent heat stored in the phase change material 102 of said at least one capture device 100, of causing the desorption of carbon dioxide which can then be captured / recovered within the enclosure 1002 by the suction generated by the vacuum pump 1007.

[0100] It follows from what has been described above that the 1000 capture enclosure preferentially comprises: • a first configuration, in particular called adsorption, in which the capture assembly 1001 is positioned (second position) in whole or in part outside the enclosure 1002 and in which the closure element 1005 is in its open configuration; • a second configuration, for example storage or desorption, in which the capture assembly 1001 is positioned (first position) in the enclosure 1002 and in which the sealing element 1005 is in its closed configuration. In the second configuration, the vacuum pump 1007 can be activated. The difference between the first and second configurations involves the passage of the capture assembly 1001 through the opening 1004.

[0101] The capture assembly 1001 is preferably parallelepiped-shaped.

[0102] The enclosure 1002 is preferably in the form of a cylindrical piece of equipment with a horizontal axis Al.

[0103] Preferably, the recovery cell 1000 is free from any additional heating means for the adsorbent 101 of said at least one capture device 100 other than the phase-change material 102 of said at least one capture device 100. In other words, preferably, no electrical energy is used to heat the adsorbent 101 of said at least one capture device 100 within the enclosure 1002.

[0104] The conveyor 1006 can be configured to move the capture assembly 1001 in a bidirectional translational motion, preferably substantially horizontal.

[0105] For this purpose, the conveyor 1006 may include a support 1008 and bearings 1009, the support 1008 being mounted on the bearings 1009, for example, in a sliding joint. Alternatively to the bearings 1009, the conveyor 1006 may include movable rails on which the support 1008 is mounted.

[0106] In Figure 3, the conveyor 1006 is included within the enclosure 1002 when the capture assembly 1001 is positioned in the internal volume 1003 of the enclosure 1002 and the closing device 1005 is in its closed configuration. This particular embodiment is not limiting, as the conveyor 1006 could just as easily be a loading and unloading device (also called a loader) external to the enclosure 1002. In this case, after positioning the capture assembly 1001 within the enclosure 1002, the conveyor is moved out through the opening 1004 to allow the closing device 1005 to move from its open to its closed configuration.

[0107] Preferably, the 1005 obturation organ is such that it varies between its opening configuration and its closing configuration according to a bidirectional translational movement, preferably substantially horizontal: this avoids energy expenditure related to gravity and thus helps to limit the electrical energy consumed by the 1000 recovery cell.

[0108] In particular, the shuttering element 1005 is mechanically linked to the enclosure 1002 in a way that allows it to vary between its open configuration and its closed configuration.

[0109] Although conveyor 1006 allows the capture assembly 1001 to be moved in a bidirectional translational motion to limit power consumption, conveyor 1006 can also alternatively move vertically. In this case, conveyor 1006 can act as an elevator.

[0110] Advantageously, the capture assembly 1001 comprises several stacked carbon dioxide capture devices 100 (i.e. forming a stack of carbon dioxide capture devices 100), for example schematically represented as four in a non-limiting manner in figures 3 and 4. [yes] The formation of the aforementioned stack is facilitated when the capture devices 100 each include a tray 105. The trays 105 can then be shaped to allow their stacking while permitting the passage of air to facilitate the adsorption of carbon dioxide by the adsorbents 101 when the trays 105 are placed in the medium.

[0112] The capture devices 100 can be stacked such that the stack of capture devices 100 includes at least one passage 1010 for a fluid flowing through the stack of capture devices 100, located between / delimited between two of the capture devices 100 in this stack. This at least one passage 1010, and in particular each passage 1010, is partially delimited by the adsorbent 101 of one of the capture devices 100, which contributes to delimiting said passage 1010. Thus, in the presence of several passages 1010, each passage is located between / delimited between two of the capture devices 100 in the stack of capture devices 100. The fluid is, in particular, derived from a medium containing carbon dioxide.

[0113] For example, in figures 3 and 4, three passages 1010 are visible, the adsorbent 101 of the capture device 100 at the top of the stack being directly in contact with the medium in figure 4.

[0114] The capture devices 100 can be stacked, particularly within the recovery cell 1000, either vertically or horizontally. Figures 3 and 4 show a vertical stack of capture devices 100. A horizontal stack would involve rotating the stack 90 degrees around an axis of rotation perpendicular to the plane of Figure 3. In the case of a horizontal stack, the presence of the retaining element 109 is preferred, especially if the adsorbent 101 is in granular form.

[0115] Each passage 1010 can be associated with only one of the adsorbents 101 of the capture devices 100. In this case, the trays 105 can be stacked in the manner for example, crates with one face of an upper tray opposite its housing 106 resting on the corners of a lower tray, said face of the upper tray being turned towards the housing of the lower tray. Although said passage 1010 may be delimited partly by the adsorbent 101 of one of the carbon dioxide capture devices 100 and partly by a portion of another of the capture devices 100 distinct from its adsorbent, this configuration allows, if necessary, the fluid to "lick" the reservoir 103 when it passes through the corresponding passage 1010, resulting in an influence on the state of the phase-change material 102, which is not optimal in terms of operation for the recovery cell 1000.

[0116] Preferably, for each passage 1010, the adsorbents 101 of two adjacent capture devices 100 within the stack each contribute to delimiting a portion of said passage 1010. In other words, the capture devices 100 can be arranged end-to-end within the stack; if necessary, the reservoirs 103 of two adjacent capture devices 100 can be in contact. This allows for better carbon dioxide adsorption and improved thermal management of the phase-change material 102. This embodiment is particularly evident in Figure 7, where the stacking allows a passage 1010 to be delimited, containing the adsorbents of two adjacent capture devices 100. In Figure 7, the stack is shown as a horizontal stack, but it can just as easily be vertical. The stacking in Figure 7 can perfectly well replace the stacking in Figures 3 and 4.Here again, according to Figure 7, the advantage of the presence of the retaining element 109 is understood when the adsorbent 101 is in the form of granules.

[0117] It follows from the foregoing that the invention also relates to a method for recovering carbon dioxide by means of a carbon dioxide recovery cell 1000 as described. This recovery method, for example as illustrated in Figure 5, comprises the following successive steps: a) exposing the capture assembly 1001 at least partially (and possibly entirely) outside the enclosure 1002 in the medium containing carbon dioxide (Figure 4), from which it results: • an adsorption of carbon dioxide by the adsorbent 101 of said at least one capture device 100; • a) heat storage, this heat being derived from adsorption, by the phase-change material 102 of said at least one capture device 100; b) position the capture assembly 1001 in its first position and place the sealing member 1005 in its closed configuration (Figure 3); c) act on the absolute pressure in the enclosure 1002 (in particular by reducing it and more particularly by setting it to a value less than or equal to 0.1 mbar) housing the capture assembly 1001 by actuation of the vacuum pump 1007 to recover carbon dioxide from the adsorbent 101 of said at least one capture device 100; the phase-change material 102 of said at least one capture device 100 releasing, during step c), heat to heat the adsorbent 101 of said at least one capture device 100. In particular, during step a) the capture assembly 1001 is in its second position.

[0118] Of course, when the capture assembly 1001 includes several capture devices 100: • step a) is such that, for each capture device 100, there results in: o an adsorption of carbon dioxide by the adsorbent 101 of said capture device 100; o a storage of heat, resulting from said adsorption, by the phase change material 102 of said capture device 100; • step c) is such that the absolute pressure in the enclosure 1002 allows carbon dioxide to be recovered from the adsorbent 101 of each of the capture devices 100; • for each capture device 100, the phase-change material 102 of said capture device 100 releases, during step c), heat enabling the heating of the adsorbent 101 of said capture device 100.

[0119] Preferably, the carbon dioxide recovery process includes a step El of monitoring at least one physical parameter of the medium, and a step E2 of choosing (in particular implemented several times during step El) whether to implement an adsorption phase phi or a desorption phase ph2 taking into account data from the monitoring step El, the adsorption phase phi consisting of implementing step a), the desorption phase ph2 consisting of implementing steps b) and c).

[0120] Each physical parameter can be chosen from among the following: the temperature of the medium and the water vapor fraction of the medium; the aim being to subject the capture assembly 1001 to the medium when the medium temperatures are low and the medium humidity is suitable. Preferably, during the monitoring step 11, the temperature of the medium and the water vapor fraction of the medium are monitored as physical parameters by sensors. These data on the temperature of the medium and the water vapor fraction of the medium allow for appropriate control, particularly in real time, of the carbon dioxide recovery process.

[0121] According to a degraded, and therefore non-preferential, mode, for example when the sensors are faulty or not present, the temperature curve of a given day and the water vapor fraction curve of the given day, for example established on averages of previous years or possibly on predictions, can be used to deduce the most favorable times for carbon dioxide capture where it will be preferable to carry out adsorption and the least favorable times where it will be preferable to carry out desorption in order to appropriately control the operation of the carbon dioxide recovery process.

[0122] For example, it is chosen to implement the phi phase of adsorption during low temperatures (e.g. below 10°C) and suitable humidity (mornings) and to implement the ph2 phase of desorption when temperatures are higher in the afternoon.

[0123] It is known in the field of carbon dioxide adsorption that an optimal operating range is associated in particular with a relative humidity range between 20% and 60% (corresponding to the aforementioned suitable humidity), or expressed differently associated with a mole fraction (i.e. the water vapor fraction of the medium) between 0.6% and 1.8%.

[0124] High humidity (>80%) presents risks of condensation on adsorbent 101 and degradation of its physical properties.

[0125] Thus, in the case of high humidity, for example above 80%, the capture assembly 1001 is preferentially stored in the enclosure 1002, which is closed by the sealing device 1005. This storage decision can be made during the monitoring step 11 in order to protect the adsorbent 101.

[0126] In the case of relative humidity (also known by the abbreviation HR) between 20% and 60%, the phi phase of adsorption can be chosen if the temperature conditions are rather low (for example below 10°C).

[0127] Typically, temperature conditions can be considered satisfied for choosing the phi phase of adsorption when the temperature is below a reference average temperature corresponding, for example, for a given period (month or year for example), to the average of the minimum daily temperatures.

[0128] Thus, the recovery cell 1000 may include an electronic control module 1011 comprising at least one temperature sensor for measuring the temperature outside the enclosure 1002 and / or a sensor for measuring a representative value of the water vapor fraction or relative humidity outside the enclosure 1002. This electronic control module 1011 is then configured to selectively control, based on the data measured by said at least one temperature sensor and / or by the sensor for measuring a representative value of the water vapor fraction or relative humidity outside the enclosure 1002, the implementation of the first configuration or the second configuration. Thus, steps E1 and E2 can be implemented by the electronic control module 1011.

[0129] A specific example of carbon dioxide capture is now described, in which the medium considered, i.e., the carbon dioxide source, is outside air with a constant carbon dioxide concentration of 430 ppm, corresponding to a partial pressure of carbon dioxide of 0.43 mbar. The medium is such that its temperature is likely to vary between 5 °C and 30 °C and its relative humidity between 10% and 90% during a given month of the year. The psychrometric chart for air at standard atmospheric pressure (101,300 Pa), which is well-known, allows us to understand the changes in temperature and humidity at different points in time. times of day. Indeed, when the air cools, the relative humidity increases (at the same weight of water) and vice versa. The adsorption capacity of the capture device 100 is favored at lower temperatures. The operating mode of the carbon dioxide recovery process can be described according to the following operating rules: RH > threshold (60% in the example), the capture unit 1001 is entered into the recovery cell 1000. When RH < 60%, if the temperature shows a change in its evolution (peak or trough), then the adsorption operation is carried out after temperature troughs and regenerations after temperature peaks.

[0130] In the particular example, adsorbent 101 includes SIESIX-3-Ni as MOL.

[0131] To form the adsorbent 101, the latter comprises a support made of activated carbon pellets impregnated with SIESIX-3-Ni. For this purpose, a solution comprising SIESIX-3-Ni, a solvent (for example an alcohol such as ethanol), and a PVA-type binder (abbreviation for "Polyvinyl Alcohol" in English, corresponding to polyvinyl alcohol in French) is used to impregnate the pellets with activated carbon before drying them.

[0132] The phase-change material 102 is, in the particular example, an iso-proportional mixture of C14H30, C15H32, C16H34, C18H38.

[0133] In this particular example, the vacuum pump 1007 used makes it possible to obtain a limiting vacuum of 0.02 mbar absolute pressure in the chamber 1002 for a flow rate of 100 m 3 / h.

[0134] Preferably, the adsorbent 101 has a height hl (figure 2) less than or equal to 5 cm to minimize resistance to carbon dioxide transfer.

[0135] In this particular example, this height hl is 5 cm. In this case, considering a 105 platform allowing a surface area of ​​1 m 2 of adsorbent 101, the volume of adsorbent 101 will be 50 liters, the apparent density of adsorbent 101 being 750 kg / m³ 3 The mass loading rate of MOL within the adsorbent (including the activated carbon pellet support) is 20%. The mass of MOL is therefore 0.05 x 750 x 0.02 = 0.75 kg.

[0136] In this particular example, the phase-change material 102 is formed from a layer of thickness el equal to 5 mm, resulting in a volume of phase-change material of 5 liters. The walls of the tank 103 are then made of sheet metal with a thickness of 1 mm.

[0137] The tray 105, according to the specific example, comprises the reservoir 103 with a height h2 of 7 mm, an adsorbent bed (i.e., the housing 106) with a thickness of 50 mm (equal to hl), and a free space zl of 13 mm above the adsorbent bed 101 for air circulation. The assembly will therefore have a height h3 of 70 mm.

[0138] The recovery process using the capture device 100, according to the particular example, preferentially takes into account the external temperature conditions and water vapor fraction to control the exposure times of the adsorbent. 101 so that it is in the best conditions for capturing carbon dioxide as mentioned above.

[0139] The specific example described above naturally depends on the context of the carbon dioxide capture, which allows for the characterization and sizing of the adsorbent 101 and the phase-change material 102. In particular, the capture device 100, and therefore the recovery cell 1000, can be sized by taking into account the source medium of the carbon dioxide as the starting point for sizing, considering essential parameters such as the carbon dioxide content, temperature, and humidity of the medium. From these values, it is possible to determine the expected characteristics and performance of the capture system (the recovery cell 1000, or more generally, the capture device 100) and thus optimize it.

[0140] The values ​​typically encountered for carbon dioxide content are in the range between the carbon dioxide content in the air and the carbon dioxide content in boiler fumes, i.e. between 430 ppm by volume and 10% by volume.

[0141] The temperature of the medium determines the adsorption curve used for adsorbent 101. Indeed, the higher the temperature, the flatter the adsorption curve. The main consequence is a lower quantity of carbon dioxide recovered per cycle (adsorption plus desorption). It is therefore important to know the temperature range in which the medium operates to choose an efficient adsorbent 101.

[0142] The temperature range also helps identify the phase-change material 102. Indeed, the melting temperature range of the phase-change material 102 must be chosen below the average low temperature of the medium. The average low temperature of the medium corresponds, for a given period (month or year, for example), to the average of the daily minimum temperatures.

[0143] Regarding humidity, the volume fraction of water vapor in the medium influences the carbon dioxide uptake of adsorbent 101. To simplify, there is competition between carbon dioxide adsorption and water adsorption at high water vapor fractions. Conversely, adsorption is maximized when there is little water vapor.

[0144] In the case of a "point source" type carbon dioxide capture, the temperature and humidity are generally fixed, which allows for more precise sizing adjustment.

[0145] In the case of the DAC, it is the appropriate control of the 1000 recovery cell according to the temperature of the environment and the relative humidity of the environment that ensures that it is in correct operating conditions.

[0146] In general, the 1000 recovery cell is advantageously suited to the DAC in the sense that, unlike industrial devices that impose productivity through the use of machines, the 1000 recovery cell as described is particularly well suited to taking advantage of the long time allowed for the adsorbent. 101 to eliminate the need for machines such as circulation fans or complex heating systems, for example, heat pumps. Furthermore, such a recovery cell 1000 can easily be positioned in locations offering favorable atmospheric conditions, such as wind for air circulation, low relative humidity between 20% and 60%, and day / night temperature variations. Within the context of the DAC (Dynamic Air Conditioning), exposure times can be very long so that equilibrium is reached naturally. Of course, depending on the adsorbent material chosen, the dynamics of mass and heat transfer are not always of the same order of magnitude. In the case of the invention, the adsorbent material is chosen to be saturated with CO2 at the outside temperature.

[0147] In the field of air treatment, it is also possible to use the 100 capture device at the level of air handling units. In this type of installation, implementation is easy because air circulation and temperatures are inherently controlled by the air handling unit.

[0148] In general, the capture device 100 allows, for example, limiting the power supply to the recovery cell 1000 to the mechanical components formed by the sealing component 1005, the vacuum pump 1007, and a control unit allowing the decision to be made regarding which adsorption or desorption phase should be implemented.

[0149] In order to limit the consumption of electrical energy from sources external to the recovery cell 1000, the latter can be equipped with solar (photovoltaic) panels associated with a battery allowing the storage of electrical energy from the solar panels in order to return this energy to the vacuum pump 1007.

[0150] The 100 capture device as described finds an industrial application in the capture of carbon dioxide.

Claims

Demands 1. Carbon dioxide recovery cell (1000), said cell (1000) comprising: • a capture assembly (1001) comprising at least one carbon dioxide capture device (100); • an enclosure (1002) comprising an internal volume (1003) suitable for housing the capture assembly (1001), and an opening (1004) adapted for at least partial passage of the capture assembly (1001) through said opening (1004); • a shuttering element (1005) configured to adopt a closing configuration in which the shuttering element (1005) closes the opening (1004); • a conveyor (1006) configured to move the capture assembly (1001) between a first position where the capture assembly (1001) is in the internal volume (1003) and a second position where the capture assembly (1001) is at least partly located outside the internal volume (1003); • a vacuum pump (1007) configured to reduce the absolute pressure in the enclosure (1002); the carbon dioxide capture device (100) comprising: • a carbon dioxide adsorbent (101); • a phase-change material (102); the phase-change material (102) being configured such that: • store heat from the adsorbent (101) during the adsorption of carbon dioxide by the adsorbent (101); • release heat to heat the adsorbent (101) in order to allow desorption of carbon dioxide by the adsorbent (101).

2. Carbon dioxide recovery cell (1000) according to claim 1, wherein the conveyor (1006) is configured to move the capture assembly (1001) in a bidirectional translational movement, preferably substantially horizontal.

3. Carbon dioxide recovery cell (1000) according to any one of claims 1 to 2, wherein the carbon dioxide capture device (100) comprises beads (108) and the phase change material (102) is distributed in the beads (108), at least a portion of the beads (108) being in contact with the adsorbent (101).

4. Carbon dioxide recovery cell (1000) according to any one of claims 1 to 3, wherein the phase-change material (102) is integrated into the mass of the adsorbent (101).

5. Carbon dioxide recovery cell (1000) according to any one of claims 1 to 2, wherein the carbon dioxide capture device (100) comprises a reservoir (103) containing the phase-change material (102), said reservoir (103) being configured to permit heat exchange between the adsorbent (101) and the phase-change material (102).

6. Carbon dioxide recovery cell (1000) according to claim 5, in which the carbon dioxide capture device (100) comprises a tray (105), said tray (105) comprising a housing (106) in which the adsorbent (101) is arranged at least in part, the housing (106) comprising a bottom (107) delimited at least in part by the reservoir (103).

7. Carbon dioxide recovery cell (1000) according to any one of claims 1 to 6, wherein the adsorbent (101) comprises a material selected from: a metal-organic network, an activated carbon, a resin, a zeolite, and / or wherein the phase-change material (102) comprises at least one alkane and preferably a mixture of alkanes.

8. Carbon dioxide recovery cell (1000) according to any one of claims 1 to 7, wherein the capture assembly (1001) comprises several stacked carbon dioxide capture devices (100).

9. Carbon dioxide recovery cell (1000) according to claim 8, wherein the carbon dioxide capture devices (100) are stacked such that the stack of carbon dioxide capture devices (100) comprises at least one passage (1010) for a fluid passing through the stack of carbon dioxide capture devices (100) between two of the carbon dioxide capture devices (100) of this stack, said at least one passage (1010) being delimited in part by the adsorbent (101) of one of the carbon dioxide capture devices (100).

10. Carbon dioxide recovery cell (1000) according to claim 9, wherein, for each passage (1010), the adsorbents (101) of two adjacent carbon dioxide capture devices (100) within the stack each participate in delimiting a part of said passage (1010).

11. Method for recovering carbon dioxide by a recovery cell (1000) according to any one of claims 1 to 10, comprising the following successive steps: a) exposing the capture assembly (1001) at least partially outside the enclosure (1002) in a medium containing carbon dioxide resulting in: adsorption of carbon dioxide by the adsorbent (101) of said at least one carbon dioxide capture device (100); a) heat storage, resulting from adsorption, by the phase-change material (102) of said at least one carbon dioxide capture device (100); b) positioning the capture assembly (1001) in its first position and placing the sealing member (1005) in its closed configuration; c) acting on the absolute pressure in the enclosure (1002) housing the capture assembly (1001) by actuation of the vacuum pump (1007) to recover carbon dioxide from the adsorbent (101) of said at least one carbon dioxide capture device (100); the phase-change material (102) of said at least one carbon dioxide capture device (100) releasing, during step c), heat to heat the adsorbent (101) of said at least one carbon dioxide capture device (100).

12. A method according to claim 12, characterized in that it comprises a step (El) of monitoring at least one physical parameter of the medium and a step (E2) of choosing an implementation of an adsorption phase (phi) or a desorption phase (ph2) taking into account data from the monitoring step (El), the adsorption phase (phi) consisting of implementing step a), the desorption phase (ph2) consisting of implementing steps b) and c).

13. Carbon dioxide capture device (100) comprising: • a carbon dioxide adsorbent (101); • a phase change material (102); • a reservoir (103) containing the phase-change material (102), said reservoir (103) being configured to allow heat exchange between the adsorbent (101) and the phase-change material (102); the phase-change material (102) being configured such that: • store heat from the adsorbent (101) during the adsorption of carbon dioxide by the adsorbent (101); • to release heat to heat the adsorbent (101) in order to allow desorption of carbon dioxide by the adsorbent (101). characterized in that it comprises a tray (105), said tray (105) comprising a housing (106) in which the adsorbent (101) is arranged at least in part, the housing (106) comprising a bottom (107) delimited at least in part by the reservoir (103).

14. Carbon dioxide capture device (100) according to claim 13, wherein the adsorbent (101) comprises a material selected from: a metallo-organic network, an activated carbon, a resin, a zeolite, and / or wherein the phase-change material (102) comprises at least one alkane and preferably a mixture of alkanes.

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