Moving bed desorption assembly

Abstract

Aspects of the present invention relate to a moving bed desorption assembly for recovery of sorbent loaded with CO2 from ambient air, comprising: a desorption chamber for removing CO2 from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and at least one first heat exchanger, a pre-heating unit configured to pre-heat the CO2-loaded sorbent and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent and being in communication with the discharge outlet of the desorption chamber.

Description

[0001] MOVING BED DESORPTION ASSEMBLY

[0002] [1] The present disclosure relates to a moving bed desorption assembly for the recovery of sorbent loaded with CO2, specifically captured by direct air capture (DAC) from ambient air.

[0003] BACKGROUND

[0004] [2] Direct air capture (DAC) is a method of capturing carbon dioxide (CO2) directly from the atmosphere that gains significant traction as a potential tool for mitigating greenhouse gas impact.

[0005] [3] Gas separation through adsorption and desorption procedures, particularly the extraction of carbon dioxide from the atmosphere, referred to as direct air capture (DAC), is an increasingly vital area in the effort to mitigate the impact of greenhouse gases.

[0006] [4] DAC process typically involves a step of moving ambient air through a bed of a solid sorbent that is effective at selectively capturing a significant portion of the CO2included therein. Due to the low concentrations (currently a little over 400 parts per million) of CO2in ambient air, high volumes of ambient air need to be moved and processed in a DAC process. Once the sorbent reaches a level of significant saturation of CO2, it needs to be regenerated in a further step. During regeneration, the adsorbent bed is treated with, for example, heat, vacuum, moisture, steam, or some combination thereof to cause the CO2to desorb from the sorbent.

[0007] [5] To optimize CO2capture, diverse configurations of adsorption and desorption units are utilized, each tailored to the specific demands of the process. An innovative alternative is the moving bed configuration, which facilitates the transport of the sorbent between distinct adsorption and desorption units.

[0008] [6] Moving bed systems continuously capture CO2from air. In a moving bed system, the sorbent material, which is capable of selectively adsorbing CO2from the air, may be continuously fed into the top of the adsorption assembly. Fresh sorbent, a material that attracts CO2, enters an adsorption chamber where it continuously meets a stream of air. The carbon dioxide (CO2)-loaded sorbent can then be sent to a separate chamber for CO2release using heat, vacuum, pressure, and / or steam. This regenerated sorbent then may return to the top of the adsorption assembly, restarting the cycle for uninterrupted CO2capture with high efficiency.

[0009] [7] The regeneration of the sorbent where captured CO2is released from the sorbent material dictates the system overall energy requirements, which must be minimized for realistic DAC operations. [8] However, the current desorption methods, predominantly heat-based desorption methods, face challenges such as high energy demands, which escalate operational costs and environmental impact due to increased energy production needs.

[0010] [9] An additional challenge lies in maintaining the sorbent's effectiveness. High temperatures and exposure to oxygen during regeneration can degrade the sorbent material, reducing its capacity to capture CO2. Therefore, optimizing DAC systems requires not only energy efficiency but also careful control of regeneration conditions to ensure the sorbent's longevity.

[0011]

[0010] This situation underscores the need for innovative desorption strategies that address these issues, fostering more sustainable and economically viable direct air capture (DAC) solutions.

[0012]

[0011] It is an object of the present invention to solve, minimize or at least reduce one or more of the above problems.

[0013] BRIEF SUMMARY

[0014]

[0012] The present invention aims to optimize the process of CO2release from a sorbent material, while minimizingthe energy consumption of the process and optimizing the capacity of the desorption system. It relates to moving bed desorption assembly designed for regenerating sorbent material that has absorbed CO2from the ambient air.

[0015]

[0013] According to a first aspect of the present invention, there is provided a moving bed desorption assembly for recovery of sorbent loaded with carbon dioxide (CO2) comprising: a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and at least one first heat exchanger, a pre-heating unit configured to pre-heat the CO2-loaded sorbent and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent and being in communication with the discharge outlet of the desorption chamber.

[0016]

[0014] The pre-heating and cooling units play a crucial role in maintaining the continuous operation of the desorption chamber, enabling it to function without the need for intermittent venting. These two units effectively isolate the desorption chamber from atmospheric pressure, maintaining its critical low-pressure and high-temperature conditions. Additionally, this temperature regulation during the regeneration process helps maintain the sorbent's effectiveness over a longer period. By avoiding extreme temperatures and minimizing exposure to oxygen, the assembly protects the sorbent from rapid degradation, thus enhancing its longevity and performance in capturing CO2.

[0015] Further, the present invention relates to a moving bed cyclic adsorption and desorption system configured for transfer of sorbent material through spatially separated (physically separate zones) adsorption and desorption assemblies, wherein the sorbent is regenerated by thermal desorption using an integrated heat exchanger, such as a pillow plate heat exchanger, to enable efficient heat transfer and enhanced process control. In a moving bed system, the sorbent material, which is capable of selectively adsorbing carbon dioxide (and water) from the air, is continuously fed into the top of the adsorption assembly, that comprises an adsorption chamber. In the adsorption chamber the adsorption process takes place at ambient atmospheric conditions (e.g. at ambient temperatures of -20° C to + 50° C) and at ambient atmospheric pressure. Further, this adsorption and desorption system may allow for both continuous operation, semi-continuous and batch processes. In some embodiments, the moving bed cyclic adsorption and desorption system operates in a non-continuous (batch or semi-batch) mode rather than in a fully continuous operation. The saturated sorbent exits the adsorption chamber and is transferred to the desorption chamber using a transportation system. The constant renewal of sorbent surfaces exposed to the air stream enhances the adsorption capacity and efficiency. The design allows for the sorbent to move dynamically, typically vertically downwards, under the influence of gravity.

[0017]

[0016] As the sorbent descends, it comes into continuous contact with an air stream. This continuous movement ensures that fresh sorbent surfaces are always available for adsorption, maximizing the CO2capture efficiency. The contact between the sorbent and the air is crucial for adsorbing CO2efficiently from the ambient air.

[0018]

[0017] After the sorbent material becomes loaded with CO2, it exits the bottom of the adsorption chamber. It is then transported to a separate desorption assembly, in this case to the pre-heating unit of the desorption assembly through a series of conduits. These conduits ensure the secure and efficient transfer of CO2-laden sorbent to the desorption site without exposing it to the atmosphere, thus preventing any release of the captured CO2.

[0019]

[0018] In the desorption assembly, more specifically in the desorption chamber, the sorbent is exposed to conditions (such as increased temperature and / or reduced pressure, in particular reduced partial pressure of CO2) that cause it to release the adsorbed CO2. This process is critical for regenerating the sorbent, making it ready for reuse in the adsorption chamber, and for concentrating CO2for storage or utilization.

[0020]

[0019] Once the desorption process in the desorption chamber is complete, the regenerated sorbent is transported to a cooling unit and then back to the adsorption chamber, completing the cycle. This cyclic operation allows for a continuous process of CO2capture and release, making it an effective and efficient system for carbon capture and sequestration or utilization.

[0021]

[0020] In some embodiments, the adsorption and desorption chambers in the moving bed system operate at different speeds, resulting in a non-continuous operation.

[0022]

[0021] Advantageously, the desorption chamber can be a low-pressure enclosure, wherein the low- pressure enclosure is a vacuum chamber configured to operate under vacuum conditions.

[0023]

[0022] Advantageously, the at least one first heat-exchanger can be a pillow-plate heat exchanger, more preferably the desorption chamber comprises a plurality of pillow-plate heat exchangers, wherein each pillow plate heat exchanger comprises two plates welded together forming a series of pillow-like indentations on both sides of the plates, wherein the series of pillow-like indentations have internal channels for heat transfer fluid to flowthrough. Further, two adjacent pillow-plate heat exchangers may be conjoined in an offset alignment. The two adjacent pillow-plate heat exchangers may form an external channel for the circulation of the CO2-loaded sorbent.

[0024]

[0023] Advantageously, the pre-heating unit may comprise at least one second heat exchanger configured to pre-heat the CO2-loaded sorbent to a first temperature, wherein the at least one second heat exchanger is a pillow plate heat-exchanger, wherein the first temperature can be in the range of from 40°C to 75°C.

[0025]

[0024] Advantageously, both the pre-heating and the cooling units may be configured to operate at low pressure, ranging from 20 mbar absolute to 400 mbar absolute, as well as at ambient pressure.

[0026]

[0025]

[0027]

[0026] Advantageously, the moving bed desorption assembly may further comprise at least one conduit system, featuring at least one pump, configured to cycle the heat transfer fluid between the pre-heating unit and the cooling unit.

[0028]

[0027] Advantageously, the cooling unit comprises at least one third heat exchanger configured to cool recovered sorbent to a third temperature, wherein the third temperature can be in the range of from 50°C to 70°C, preferably 55°C to 60°C. Further, the third heat exchanger can be a pillow plate heat exchanger.

[0029]

[0028] Advantageously, each of the first, second and third pillow plate heat exchangers comprises two plates welded together forming a series of pillow-like indentations on both sides of the plates, wherein the series of pillow-like indentations have internal channels for heat transfer fluid to flow through. Further, the pre-heating unit, the desorption chamber, and the cooling unit may each comprise a plurality of the first, second, and third heat exchangers, respectively, which are identified respectively as the first, second, and third pillow-plate heat exchangers. Also, two adjacent first, second or third pillow-plate heat exchangers may be configured to form an external channel for the passing of CO2-loaded sorbent. In addition, two adjacent pillow-plate heat exchangers, either from the first, second, or third pillow-plate heat exchangers, may be conjoined in an offset alignment. Thus, in each unit of the desorption assembly, two adjacent pillow-plate heat exchangers (defined respectively as the first, second, or third heat exchangers) are conjoined in a staggered arrangement. This staggered arrangement minimizes the space between two adjacent heat exchangers. Further, the total number of pillow-plate heat exchangers per unit may vary depending on the system scale and operational requirements.

[0030]

[0029] In some embodiments, a pillow plate pitch (d1) defined as distance measured between the welded parts of two adjacent pillow plate heat exchangers, i.e. first, second or third pillow-plate heat exchangers, is between 5 mm and 30 mm. In an embodiment, the thickness (d3) of the welded parts of the pillow plates can be in the range of from 0.5 mm to 20 mm, or of form 0.5 mm to 10 mm.

[0031]

[0030] Further, the desorption chamber may comprise at least one valve configured to regulate the flow rate of the sorbent, i.e. volume of sorbent that passes through a given point within the system per unit of time.

[0032]

[0031] Further, the sorbent can be a polymeric solid sorbent in the form of beads.

[0033]

[0032] In various embodiments, the polymeric solid sorbent is an amine-functionalized polymeric ionexchange resin, preferably a primary amine-functionalized polymeric ion-exchange resin.

[0034]

[0033] In a further aspect, there is provided a method for regenerating carbon dioxide (CO2) -loaded sorbent within a moving bed desorption assembly according to the first aspect, the method comprising the following steps:

[0035]

[0034] a) introducing a CO2-loaded sorbent in a pre-heating unit of the moving bed desorption assembly,

[0036]

[0035] b) heating the CO2- loaded sorbent within the pre-heating unit to elevate its temperature from starting temperature in the range of from -20°C to 50°C to a first temperature through heat exchange with a heat transfer fluid, wherein the first temperature is higher than the starting temperature,

[0037]

[0036] c) transferring the pre-heated sorbent into a desorption chamber, and adjusting the temperature of the CO2loaded sorbent to a second temperature, while applying vacuum of from 20 to 400 mbar absolute, wherein the second temperature is higher than the first temperature,

[0038]

[0037] d) releasing the CO2from the sorbent thereby regenerating the sorbent for subsequent CO2capture cycles,

[0038] e) cooling the regenerated sorbent in a cooling unit to a third temperature through heat exchange with the heat transfer fluid, by transferring heat to the heat transfer fluid, wherein the third temperature is lower than the second temperature and equal or higher than the first temperature,

[0039]

[0039] f) circulating the heat transfer fluid between the cooling and pre-heating units in a closed loop for heat recovery.

[0040]

[0040] The heat transfer fluid circulating in the closed loop may absorb heat from the regenerated sorbent in the cooling unit and subsequently may transfer heat to pre-heat the CO2- loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2-loaded sorbent in the pre-heating unit may be utilized to cool the regenerated sorbent within the cooling unit.

[0041]

[0041] In an embodiment, the starting temperature is in the range of from -10°C to 50 °C, -5°C to 45°C, 0°C to 45°C, 5 °C to 40°C.

[0042]

[0042] In an exemplary embodiment, the starting temperature can be between 0°C to 45°C, 10°C to 40°C, 15°C to 35°C, 15°C to 25°C.

[0043]

[0043] In an embodiment, the first temperature is in the range of from 40°C to 75°C, 40°C to 60°C, more preferably 45°C to 65°C, more preferably 55°C.

[0044]

[0044] In an embodiment, the second temperature is in the range of from 85°C to 130°C, more preferably 90 °C to 120°C, even more preferably 90°C to 110°C.

[0045]

[0045] In an embodiment, the second temperature is in the range of from 85°C to 105°C, even more preferably the second temperature is in the range of from 90°C to 100°C.

[0046]

[0046] In an embodiment, the third temperature is in the range of from 40°C to 70°C, preferably 50°C to 70°C, 50°C to 60°C, more preferably in the range of from 55°C to 60°C.

[0047]

[0047] In an embodiment, the heat transfer fluid is liquid, preferably water.

[0048]

[0048] In an embodiment, the vacuum applied to the desorption chamber is in the range of from 40 mbar absolute to 60 mbar absolute, preferably 50 mbar absolute.

[0049]

[0049] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim, accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. BRIEF DESCRIPTION OFTHE SEVERALVIEWS OFTHE DRAWINGS

[0050]

[0050] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0051]

[0051] FIG. 1 illustrates an aspect of the subject matter in accordance with one embodiment. FIG. 1 shows schematic representation of the desorption assembly, the desorption phase and the heat recovery mechanism as implemented in the present invention. FIG. 1 depicts a pre-heating unit 10, a desorption chamber 20 and a cooling unit 30.

[0052]

[0052] FIG. 2 illustrates an aspect of the subject matter in accordance with one embodiment. FIG. 2 depicts the configuration of pillow plate heat exchangers inside the desorption chamber. The section marked A-A presents a cross-sectional view taken along the longitudinal axis of the chamber, while section B (1 :5) provides a detailed view of the offset arrangement of the pillow plates heat exchangers in the desorption chamber.

[0053]

[0053] FIG. 3 illustrates an aspect of the subject matter in accordance with one embodiment. FIG. 3 is a detailed view of the offset arrangement of the pillow plates heat exchangers in the desorption chamber.

[0054]

[0054] Fig. 4 is a schematic illustration of the moving bed desorption assembly 42, showing the preheating unit 10 along with the pillow-plate heat-exchangers 14, the desorption chamber 10 along with its the pillow-plate heat exchangers 20, the cooling unit 30 along with its pillow-plate heat-exchangers 31 , and transportation system 11 .

[0055]

[0055] Fig. 5 is a schematic illustration of the moving-bed desorption assembly 42 also depicted in Fig. 4, showing pre-heating unit 10, desorption chamber 20, and cooling unit 30, transportation system 11 .Fig. 6 illustrates system 100 for separation of carbon dioxide from ambient air featuring at least one moving bed adsorption assembly 40, and a moving bed desorption assembly 42 comprising a preheating unit 10, a desorption chamber 20, and a colling unit 30.

[0056] DETAILED DESCRIPTION

[0057]

[0056] The present invention relates to a moving bed desorption assembly in a moving bed system for CO2direct air capture to minimize energy consumption by optimizing heat recovery and precisely controlling the temperature of the sorbent. In the moving bed system, the sorbent is circulated from the adsorption assembly to the desorption assembly, and vice versa.

[0058]

[0057] The moving bed desorption assembly (hereinafter the “desorption assembly”) of the present invention is configured to release carbon dioxide from the sorbent, which is loaded with CO2, through the application of thermal energy, specifically, by heating the sorbent material. The moving bed adsorption assembly comprises a pre-heating unit, a desorption chamber and a cooling unit.

[0058] Preferably, the pre-heating unit, the desorption chamber, and the cooling unit, are separate units. Each of the pre-heating unit, desorption chamber and the cooling unit each comprise a separate low-pressure enclosure (a vacuum chamber -a first vacuum chamber, a second vacuum chamber and a third vacuum chamber), while being interconnected to facilitate sorbent movement between the units. Each of the first, second and third vacuum chambers are sealed and independently maintainable at a vacuum level, and the first, second and third vacuum chambers are isolated from one another.

[0059]

[0059] In a first aspect of the present invention, there is provided a moving bed desorption assembly for recovery of sorbent loaded with CO2comprising: a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and at least one first heat exchanger, a pre-heating unit configured to pre-heat the loaded sorbent and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent and being in communication with the discharge outlet of the desorption chamber.

[0060]

[0060] The pre-heating and cooling units may play a crucial role in maintaining the low-pressure environment within the desorption chamber. These units can switch between different pressure levels- ambient pressure and low pressure, the low pressure ranging from 20 mbar absolute to 400 mbar absolute. This operation is synchronized with the loading and unloading cycles of the sorbent material. The pre-heating and cooling units together act as a vacuum lock or buffer, preventing outside air from entering the desorption chamber during sorbent transfers, maintaining the low-pressure environment throughout the entire process cycle.

[0061]

[0061] In another aspect of the present invention, there is provided a method for regenerating CO2loaded sorbent within a moving bed desorption assembly, wherein the moving bed desorption assembly for recovery of sorbent loaded with CO2from ambient air, comprises a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and at least one first heat exchanger, a pre-heating unit configured to pre-heat the CO2-loaded sorbent and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent and being in communication with the discharge outlet of the desorption chamber, the method comprising the following steps: a) introducing a CO2-loaded sorbent in a pre-heating unit of the moving bed desorption assembly, b) heating the CO2-loaded sorbent within the pre-heating unit to elevate its temperature from starting temperature in the range of from -20°C to 50°C to a first temperature through heat exchange with a heat transfer fluid, wherein the first temperature is higher than the starting temperature, c) transferring the pre-heated sorbent into a desorption chamber, and adjusting the temperature of the CO2- loaded sorbent to a second temperature, while applying vacuum of from 20 to 400 mbar absolute, wherein the second temperature is higher than the first temperature, d) releasing the CO2from the sorbent thereby regenerating the sorbent for subsequent CO2capture cycles, e) cooling the regenerated sorbent in a cooling unit to a third temperature through heat exchange with the heat transfer fluid, by transferring heat to the heat transfer fluid, wherein the third temperature is lower than the second temperature and equal or higher than the first temperature, f) circulating the heat transfer fluid between the cooling and pre-heating units in a closed loop for heat recovery.

[0062]

[0062] In a further aspect, there is provided a system for separation of carbon dioxide from ambient air comprising a moving bed adsorption assembly for capturing CO2from ambient air comprising an adsorption chamber configured to capture carbon dioxide from a gas stream, and comprising a plurality of cartridges, at least one air inlet, at least one gas outlet(s), at least one sorbent feed inlet(s), and at least one sorbent discharge outlet(s); and a moving bed desorption assembly comprising a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, a pre-heating unit being in communication with the feed section of the desorption chamber, and a cooling unit being in communication with the discharge outlet of the desorption chamber.

[0063]

[0063] The system described above is preferably a moving bed system, in which CO2-laden sorbent circulates from the adsorption assembly to the desorption assembly for CO2release, then returns to the adsorption assembly once regenerated. Advantageously, the system for CO2 separation described above may further comprise a transportation system configured to transport a CO2-loaded sorbent from the bottom of the adsorption assembly to the top of the desorption assembly and to return the regenerated sorbent from the bottom of the desorption assembly to the top of the adsorption assembly. Examples of transportation system used in the moving bed cyclic adsorption and desorption system may include, for example, vacuum-based, pneumatic, or mechanical systems. Preferably, a mechanical transportation system is employed, which may include components such as screw conveyors, bucket elevators, belt conveyors, or disc-and-chain conveyors. For example, a disc- and-chain conveyor, or bucket conveyor can be particularly effective for transporting solid. A mechanical transportation system is generally preferred over vacuum-based systems due to their lower energy consumption and simpler operational requirements.

[0064] The system for separation of carbon dioxide further may comprises at least one conduit system configured to continuously cycle the adsorbent between the adsorption chamber and the desorption chamber.

[0064]

[0065] Terms and definitions

[0065]

[0066] The term “Direct Air capture” or “DAC” used herein refers to technologies that extract

[0066] CO2directly from the atmosphere or ambient air. The sorbent of the present invention is adapted to capture CO2from the air.

[0067]

[0067] The term “adsorption” refers to a process where molecules from a fluid bind to the surface of a solid material (the adsorbent). Different molecules have varying affinities for adsorbent materials, allowing separation.

[0068]

[0068] The term “desorption” refers to the process where CO2, previously adsorbed by a sorbent material, is released back into a gaseous state, effectively separating it from the sorbent to enable the sorbent's reuse for additional CO2capture cycles.

[0069]

[0069] The term “adsorbent bed” refers herein to a container or channel filled with a adsorbent that captures specific molecules from a gas or liquid stream as it flows through.

[0070]

[0070] The term “sorbent” refers herein to a solid material with a high surface area that attracts and holds (adsorbs) molecules from a gas or liquid on its surface.

[0071]

[0071] The terms “adsorbent”, “sorbent”, or "sorbent material" and “sorbent particles” are used herein interchangeably.

[0072]

[0072] The term “cross-flow” refers to a configuration in which two streams (typically, but not exclusively, fluids) pass by each other moving in perpendicular directions.

[0073]

[0073] The term “desorption” refers is a process of release or removal of carbon dioxide from a solid material or sorbent that has previously adsorbed or captured CO2by heating the sorbent. . This release can be achieved through various methods, such as heating (temperature swing adsorption), applying a vacuum, or a combination of both temperature and vacuum.

[0074]

[0074] The term ""sorbent bed" or “adsorbent bed” refers to a physical arrangement or layer of ad / sorbent material within a system designed for adsorption processes.

[0075]

[0075] The terms “sorbent” and “sorbent material” are used interchangeably herein.

[0076]

[0076] The terms “cartridge”, “metal cartridge”, “metal filter cartridge” are used herein interchangeably.

[0077]

[0077] The terms "plate with openings," "perforated plate," "mesh," and "porous plate" are used interchangeably herein.

[0078] The terms “perforated metal plate” and “metal plate” are used interchangeably herein.

[0078]

[0079] The term “carbon dioxide (CO2)-enriched sorbent" or “carbon dioxide loaded sorbent” refers to a sorbent material that has absorbed carbon dioxide (CO2) from a gas stream but has not necessarily reached its full adsorption capacity.

[0079]

[0080] The term "room temperature" refers to a temperature of 22°C to 25°C.

[0080]

[0081] The terms “ambient temperature “or “ambient conditions” refer to the temperature of the surrounding environment, which can range from -20 degrees Celsius to +50 degrees Celsius.

[0081]

[0082] The term "in communication" refers to the operational and functional connectivity between various system components, enabling the efficient transfer and management of sorbent.

[0082]

[0083] The terms “offset arrangement” or “offset alignment” refers herein to a configuration where elements (pillow plates) are placed in a way that they are not directly aligned or lined up with each other along a common line or axis. Instead, each element is slightly shifted or displaced in position relative to the adjacent elements.

[0083]

[0084] The term "recovered sorbent" or “regenerated sorbent” refers to a sorbent that has been regenerated or restored to its original or usable condition after being used in a process to adsorb CO2.

[0084]

[0085] Desorption chamber

[0085] The moving bed desorption assembly may be in fluid connection with the moving absorption assembly. The pre-heating unit, the desorption chamber and the cooling unit are separate units, while being interconnected, and each with its own dedicated vacuum chamber, wherein each vacuum chamber operates at low pressure ranging from 20 mbar absolute to 400 mbar absolute, as well as at ambient pressure. Each vacuum chamber may have either a rectangular or cylindrical shape. The moving bed desorption assembly may further comprise at least one vacuum pump, preferably two vacuum pumps, configured to create vacuum in the vacuum chambers.

[0086]

[0086] In FIG. 1 , a schematic representation illustrates the arrangement of a pre-heating unit 10, a desorption chamber 20, and a cooling unit 30, and a closed-loop circulation system of the heat transfer fluid.

[0087]

[0087] The moving bed desorption assembly may be configured as a vertically oriented enclosure, as shown in Fig. 5. The desorption assembly comprises a desorption chamber designed to facilitate the process of desorption. The desorption assembly is configured for a moving bed process, where the regenerated sorbent is transported from the desorption chamber back to the adsorption chamber. In a moving bed system, the CO2laden sorbent moves vertically downwards through the desorption chamber, driven by gravity. The desorption chamber is a low-pressure enclosure. Preferably, the low- pressure enclosure is a vacuum chamber configured to operate under vacuum in the range of from ranging from 20 mbar absolute to 400 mbar absolute, more preferably in the range of from 40 mbar absolute to 60 mbar absolute and a second temperature in the range of from 80°C to 150°C.The vacuum chamber is a sealed, rigid enclosure with both top, bottom and side walls. The vacuum chamber may have different shapes such as rectangular, cylindrical, spherical. In some embodiments, the vacuum chamber of the present invention may have a cylindrical shape, preferably the vacuum chamber is a vertical cylindricalvacuum chamber with a circular cross-section. In alternative embodiments, the vacuum chamber has a rectangular shape. Cylindricalvacuum chambers can be equipped with pillow plate heat exchangers by using plates of varying shapes and sizes that conform to the vacuum chamber's curved geometry. The pillow plates can be arranged in segments to create a near-cylindrical inner surface. Cylindricalvacuum chambers can be more cost effective.

[0088]

[0088] With reference to both Figs. 4 and Fig. 5, there is illustrated a moving bed desorption assembly comprising three separate units in communication with each other: a pre-heating unit 10 comprising a vacuum enclosure and pillow-plate heat exchangers 14; a desorption chamber 20 having a vacuum enclosure 20, a sorbent gutter valve, and pillow-plate heat-exchangers 25; a cooling unit 30 including a vacuum enclosure and pillow-plate heat exchangers 31 ; a transportation system 11 and transport desorption outlet 12. Each vacuum chamber (vacuum enclosure) may have a door, such as door 26. Further, all vacuum chambers may be in communication with a vacuum pump. The moving bed desorption assembly comprises a condenser (not shown) in communication with the desorption chamber. Water vapor generated during sorbent regeneration is drawn out of the desorption chamber under vacuum. The condenser provides a cold surface, and when water vapor contacts that surface it condenses it back into liquid.

[0089]

[0089] In an embodiment, the desorption chamber is a cylindricalvacuum chamber adapted to create and maintain a vacuum environment within its interior.

[0090]

[0090] The vauum chamber can be evacuated to a pressure in the range of 20 to 400 mbarabs, more preferably to 40 to 60 mbarabs, for example by using a vacuum pump.

[0091]

[0091] In an embodiment, the vacuum chamber operates at 50 mbara s.

[0092]

[0092] Applyig a vacuum to the desorption chamber can make the desorption of CO2from the loaded sorbent more efficient. In a lower pressure environment, gases tend to desorb more easily because the lower external pressure helps to draw the gas out of the sorbent material. This is particularly useful for regenerating the sorbent so that it can be reused to capture more CO2. The vacuum not only helps in desorbing CO2but also prepares the sorbent for another cycle of CO2capture. Efficiently removing the CO2and returning the sorbent to a state where it can effectively adsorb CO2again is crucial for continuous or repeated processes.

[0093] The CO2-loaded sorbent undergoes heating within the vacuum chamber, elevating its temperature to a range from 80°C to 130°C , more preferably 85°C to 120°C, 90°C to 110°C, 90°C to 105°C, and 95° C to 100°C. Heating the CO2-loaded sorbent within this temperature range facilitates the desorption process, where CO2molecules are released from the sorbent material. This temperature range optimizes the efficiency of CO2desorption, ensuring that a significant portion of the captured CO2is effectively released. The selected temperature range ensures that the sorbent material remains thermally stable during desorption. This helps prevent thermal degradation and maintains the integrity of the sorbent for repeated desorption cycles.

[0093]

[0094] In an embodiment, the vacuum chamber may preferably operate between 40 mbarabs to 60 mbarabs and temperature in the range of from 80°C to 120°C.

[0094]

[0095] In an embodiment, the vacuum chamber may preferably operate between 40 mbarabs to 60 mbara sand temperatures range from 90°C to 110°C.

[0095]

[0096] In an embodiment, the vacuum chamber may preferably operate between 50 mbarabsand temperature in the range of from 90°C to 105°C.

[0096]

[0097] In an embodiment, the vacuum chamber may preferably operate at 50 mbara sand temperature in the range of from 95° C to 100°C.

[0097]

[0098] The desorption chamber may comprise at its bottom at least one valve configured to regulate the flow rate of the CO2-loaded sorbent through the desorption chamber and at least one bottom hopper. More preferably, at least one valve can be a butterfly valve.

[0098]

[0099] The desorption chamber comprises at least one heat exchanger configured to heat the sorbent material. The heat exchangers may include, for example, wire coils, pillow-plate heat exchangers, plate heat exchangers, fin-tube heat exchangers, etc. More preferably, the heat-exchanger for heating the CO2-loaded sorbent can be a pillow-plate heat exchanger.

[0099]

[0100] In an embodiment, the desorption chamber comprises at least one pillow-plate heat exchanger, also referred to herein as a first pillow-plate heat exchanger, or first heat exchanger.

[0100]

[0101] In an embodiment, the desorption chamber 220 comprises a plurality of pillow-plate heat exchangers, as shown in FIG. 2, (section A-A).

[0101]

[0102] The pillow plate heat exchanger may be constructed from two metal plates (or panels), typically stainless steel, welded together at the perimeter to form a sealed envelope. Following the initial welding, strategic spot welds are then applied across the surface in a predetermined pattern that outlines where the inflation will occur, setting the stage for the creation of the pillow-like channels. After welding, the space between these pillow plates is pressurized with a fluid, either liquid or gas, causing the material to expand at the non-welded spots. This inflation process results in the formation of bulged sections or "pillows" (also called dimples) that significantly increase the surface area available for heat exchange and facilitating the flow of heat transfer fluid through the internal channels formed between the pillow plates. A pillow plate heat exchanger comprises two parallel, closely spaced metal sheets that are joined together in a regular or custom-defined pattern, creating a series of internal bulges or dimples between the sheets. The external surfaces of the sheets form the heat exchange interface.

[0102]

[0103] Thus, each pillow-plate heat exchanger may comprise a first and second metal sheets welded about their periphery and hydraulically expanded to define an internal channel and an external dimpled heat-transfer surface, which functions as an external channel or flow path for the passing of CO2-loaded sorbent. The pillow plate heat exchanger further comprises a fluid inlet and a fluid outlet in fluid communication with the internal channel(s);

[0103]

[0104] The heat transfer fluid, such as water, steam, or thermal oil, is circulated through the internal channels of the pillow plates. The heat transfer fluid (water) may utilize recovered heat from another process, Preferably the heat transfer fluid in the second pillow-plate heat exchanger can be water. The internal channels of a pillow plate heat exchanger refer to the pathways or conduits formed between the welded or bonded layers of the pillow plates themselves. These internal channels are designed to facilitate the flow of a heat transfer fluid directly within the pillow plate heat exchanger unit The external (exterior) surface of each pillow-plate heat exchanger is configured to accommodate the sorbent flow, featuring a low-amplitude convex curvature, also referred to as dimpled heat-transfer surface, that forms a continuous domed interface to ensures both smooth flow and continuous contact of the solid sorbent with the heated surface of the pillow plate heat exchanger. The CO2- loaded sorbent, carried through the desorption chamber through gravity, comes into direct contact with the heated surfaces of the pillow plates, where the heat-transfer fluid runs through the internal channels, while the solid sorbent travels over the external surface. This direct contact ensures efficient heat transfer from the pillow plates to the sorbent. The heat absorbed by the sorbent facilitates the desorption process, releasing the captured CO2.

[0104]

[0105] Pillow plate heat exchangers are employed in the moving bed desorption assembly because their embossed surfaces generate turbulence in flowing fluids, enhancing heat transfer by increasing surface area and minimizing the layer of stagnant fluid close to the surface.

[0105]

[0106] Two pillow-plate heat exchangers, positioned adjacently, create a passage or an external channel specifically designed for the flow of CO2-loaded sorbent. The CO2- loaded sorbent comes in contact with the surface of the pillow-plates. The external channels are thus formed by the surface of each pillow-plate heat exchanger between two adjacent pillow plates.

[0107] Each pillow plate heat exchanger is characterized by a maximum inner inflation distance 316, which refers to the peak distance from the original plane of the metal plates to the highest point of expansion achieved by the bulged sections, or 'pillows,' following the pressurization process, and welded parts 315, as shown in FIG. 3. The height d4 of the maximum inner inflation distance within each heat exchanger is between 4 mm and 15 mm, more preferably between 7mm and 13 mm, even more preferably between 7mm and 10 mm.

[0106]

[0108] Two adjacent pillow-plate heat exchangers positioned adjacent to each other may be arranged in a manner that offsets them from one another, thus in an offset alignment. This offset alignment, or staggered arrangement, indicates that each pillow plate within one pillow plate heat exchanger is not in direct alignment with the pillow plates in the adjacent pillow plate heat exchanger, as illustrated in FIG. 3. Instead of aligning the pillow plates directly opposite each other, they are shifted so that each pillow plate is partially overlapped by plates from the adjacent heat exchanger. This offset alignment reduces the space between two neighboring surfaces of two adjacent heat-exchangers forming a narrower and more uniformly sized external channel. This configuration optimizes the use of space within the system and enhances the flow dynamics of the sorbent, improving the overall efficiency of the heat exchange process.

[0107]

[0109] The pillow plates can be made from metal, preferably stainless steel for durability and corrosion resistance.

[0108]

[0110] FIG. 3 depicts a specific but non-limiting embodiment of the present invention, illustrating multiple pillow plate heat exchangers (300) integrated within the desorption chamber. The pillow plate heat exchangers are indicated with A1 and A2. Further, the adjacent pillow plate heat exchangers A1 and A2 are arranged in an offset alignment. In this setup, A1 and A2 are alternately positioned, with A2 slightly shifted relative to A1 . This offset configuration maximizes the effective use of available space, allowing for a more compact arrangement while maintaining efficient heat exchange capabilities.

[0109]

[0111] The pillow plate pitch denoted as d1 is herein defined as the distance measured between the welded parts 315 of two adjacent pillow plate heat exchangers. The pillow plate pitch d1 between two adjacent pillow plate heat exchangers (A1 , A2) can be in the range between 5 mm and 30 mm, preferably 6 mm and 14 mm, even more preferably between 8 mm and 13 mm. Herein pillow plate pitch d1 refers to the distance measured between the corresponding welded sections of two adjacent heat exchangers, as shown in FIG. 3.

[0110]

[0112] Ensuring proper alignment and spacing between adjacent pillow plates in the heat exchanger assembly is crucial for efficient heat transfer and structural integrity. With reference to FIG. 3 , “b2” and "b3" measurement shows the spacing or offset alignment of adjacent pillow plate heat exchangers. The lateral channel pitch b1 , as shown in FIG. 3 in a pillow-plate heat exchanger refers to the distance between adjacent welding points along the lateral (side) edges of the pillow plates.

[0111]

[0113] In pillow plate heat exchangers, the distance d2 as shown in FIG. 3, between the points of maximum inner inflation 316 of two adjacent heat exchangers can be between 1 mm and 10 mm, preferably between 2 mm and 6 mm, more preferably between 3 mm and 6 mm, even more preferably between 3 and 5 mm.

[0112]

[0114] The thickness d3 of the welded parts of the pillow plates is determined by the combined thickness of each individual pillow plate prior to inflation and can be in the range of from 0.5 mm to 20 mm, or of from 0.5 mm to 10 mm, more preferably of from 1 mm to 4 mm, or 1 mm to 2.5 mm, or 1 mm to 2 mm, or 1 .5 mm to 2 mm. The thickness of the pillow plates influences the heat transfer efficiency and mechanical strength of the heat exchanger.

[0113]

[0115] The maximum inner inflation distance d4 representing the distance between the apexes of the inflated sections of two pillow plates constituting the heat exchanger, can range from 6 mm to 18 mm, more preferably 6 mm to 16 mm, 6 mm to 15 mm, 6 mm to 13 mm, 6mm to 10 mm, 7 mm to 9 mm.

[0114]

[0116] The lateral channel pitch b1 can be in the range between 10 and 50 mm, more preferably 15 mm and 40 mm, even more preferably between 20 and 40 mm.

[0115]

[0117] With reference to Fig. 3, in accordance with an embodiment of the present invention, the pillow plate pitch d1 between two adjacent pillow plate heat exchangers (A1 , A2) is 12 mm. Further, the distance d2 between two adjacent pillow plate heat exchangers is 4 mm. The thickness d3 of two pillow plates welded together is 1 .6 mm within a single pillow plate heat exchanger. The maximum inner inflation distance d4 represents the distance between the apexes of the inflated sections of two pillow plates constituting the heat exchanger is 8 mm. The lateral channel pitch b1 is 36 mm.

[0116]

[0118] The sorbent can be heated by a heat exchanger. Although any suitable heat exchanger may be used, pillow plate heat exchangers are preferred due to their low-amplitude convex, dimpled surfaces, which significantly increase the available surface area for heat transfer between the fluid and the solid sorbent. Compared to conventional plate heat exchangers, this geometry significantly enhances thermal efficiency due to its high surface-to-volume ratio. The surface-to-volume ratio (SA / ratio) is a measure of how much surface area is available per unit volume of a material or system. For example, when a pillow plate heat exchanger is employed, the surface-to-volume ratio can achieve approximately 240 m2 / m3of solid sorbent. In comparison, conventional shell-and-tube or standard plate heat exchangers typically offer a lower surface-to-volume ratio, ranging from about 50 to

[0117] 150 m2 / m3. This increase in surface area enhances heat transfer efficiency, making pillow plate heat exchangers particularly well-suited for applications involving bulk solid sorbents. Pillow plate exchangers are cost-effective and can be designed to be modular and scalable.

[0118]

[0119] In an embodiment of the invention, the recovered sorbent may be cooled by heat exchanger, preferably by a pillow-plate heat exchanger.

[0119]

[0120] Preferably, two adjacent pillow-plate heat exchangers are conjoined in offset alignment or a staggered, as shown in FIG. 3. Further, this offset alignment of the pillow plates heat exchangers may apply uniformly across all three units within the desorption assembly: the pre-heating unit, the desorption chamber and the cooling unit.

[0120]

[0121] The heat transfer fluid can be a liquid, such as water, oil, and ethylene glycol, designed to store thermal energy and regulate heat flow. The heat transfer fluid (water) may utilize recovered heat from another process,

[0121]

[0122] The desorption assembly comprises a pre-heating unit configured to elevate the temperature of the CO2-loaded sorbent. Additionally, this pre-heating unit is designed to adjust its internal pressure, reducing it from ambient pressure to a lower level pressure consistent with the desorption chamber’s requirements.

[0122]

[0123] The pre-heating unit can pre-heat the CO2-loaded sorbent from a starting temperature in the range of from -20°C to 50°C (ambient temperature) to a first temperature of 70°C, more preferably from a starting temperature of 5°C to a first temperature of 55°C. This controlled heating prepares the CO2-loaded sorbent by raising its temperature to a level that is optimal for the subsequent desorption process. The advantage of the pre-heating step is that by starting the desorption process at a higher temperature, the energy required to reach the optimal desorption temperature is reduced. This is because the CO2-loaded sorbent is already closer to the target temperature needed for efficient CO2release, minimizingthe additional heat energy needed.

[0123]

[0124] In an embodiment, in the pre-heating unit, the temperature of the sorbent is initially increased from a starting temperature between 15°C and 25°C to a first temperature in the range of from 40°C to 75°C, more preferably to 50°C to 60°C through pre-heating.

[0124]

[0125] Further, the pre-heating step also offers opportunities for energy recovery and reuse within the desorption system. For example, heat recovered from the cooling phase and / or the desorption phase,, or other parts of the process can be used to pre-heat the sorbent, further improving overall energy efficiency and vice versa, the heat recovered from the pre-heating of the sorbent can be used for cooling of the sorbent.

[0125]

[0126] The pre-heating unit may be positioned above the desorption chamber and is connected to it via a valve. The valve is configured to open for the introduction of the pre-heated sorbent into the chamber and to close to maintain the vacuum environment during the desorption process, regulating the flow of the sorbent between the pre-heating unit and the desorption chamber. The pre-heating unit receives CO2-loaded sorbent at ambient pressure and pre-heats it is using either recovered heat from the system or an external heat source, ensuring reduced pressure during the pre-heating process.

[0126]

[0127] Pre-heating the CO2-loaded sorbent reduces the additional energy required to elevate the sorbent's temperature to the desired level within the vacuum chamber which leads to energy savings and improved efficiency. Since the sorbent is already at a relatively high temperature, it requires less time and energy to reach the desired temperature within the vacuum chamber.

[0127]

[0128] The pre-heating unit comprises at least one heat-exchanger, referred to herein as the second heat exchanger. The second heat exchanger is preferably a pillow-plate heat exchanger, also referred to as a second pillow-plate heat exchanger. Preferably the heat transfer fluid in the second pillowplate heat exchanger is liquid, more preferably water. The pre-heating unit also serves as a heat recovery unit. Each of the second pillow-plate heat exchangers comprises two plates, also referred to herein as pillow-plates, welded together forming a series of pillow-like indentations on both sides of the plates, wherein the series of pillow-like indentations have internal channels for heat transfer fluid to flowthrough. The pillow-plates of the second heat exchanger are also made of metal, preferably stainless steel. The pre-heating unit comprises a plurality of second pillow-plate heat exchangers. Adjacent heat exchangers within the pre-heating unit of the desorption assembly can be positioned in an offset configuration.

[0128]

[0129]

[0129]

[0130] The desorption assembly comprises a cooling unit. Hot sorbent exits the desorption chamber and enters the cooling unit. Cooling the hot sorbent after desorption prevents it from reaching excessively high temperatures, which could degrade the sorbent material or reduce its effectiveness in subsequent adsorption cycles. By maintaining optimal temperature conditions, the cooling unit ensures the sorbent remains in a suitable state for efficient CO2capture. The cooling unit is in communication with the desorption chamber positioned beneath the desorption chamber to cool the recovered sorbent. This configuration minimizes transfer distances and heat loss. Before the sorbent can be exposed to ambient conditions or removed from the system, the pressure in the cooling unit is gradually increased to ambient levels, ensuring a stable transition for the sorbent. he cooling unit may comprise a plurality of third pillow-plate heat exchangers. Each of the third pillow-plate heat exchangers comprise two plates, also referred to herein as pillow-plates, welded together forming a series of pillow-like indentations on both sides of the plates, wherein the series of pillow-like indentations have internal channels for heat transfer fluid to flowthrough. Adjacent heat exchangers within the cooling unit of the desorption assembly can be positioned in an offset configuration. Further, each of the third pillow-plate heat-exchanger of the cooling unit may employ water as a heat transfer fluid.

[0130]

[0131] It is important to note that while water is exemplified as a heat transfer fluid, the present invention is not limited to this heat transfer fluid alone.

[0131]

[0132] The cooling unit has a double function: it is configured to cool the recovered sorbent and also as a heat recovery unit. The regenerated sorbent exits the desorption chamber and directly enters the cooling unit for temperature reduction. The cooling unit may comprise at least one third heat exchanger. The third heat exchanger is a pillow-plate heat exchanger, also referred to as a third pillowplate heat exchanger. The regenerated sorbent is cooled in the cooling unit by transferring heat to the heat transfer fluid. This heat transfer fluid absorbs thermal energy from the hot regenerated sorbent.

[0132]

[0133] The cooling unit of the desorption assembly may further optionally comprise a liquid distribution system, preferably a water distribution system, configured to distribute liquid, preferably water, onto the regenerated sorbent to moisturize the sorbent. Preferably the regenerated sorbent is an amine-functionalized polymeric sorbent. More preferably, the sorbent used in the present invention is macroporous, divinylbenzene-crosslinked polymer in spherical bead form, functionalized with primary amine groups.

[0133]

[0134] Without being bound to any theories, it is considered that amine-functionalized polymeric sorbents are tolerant to moisture, and their capacity increases when moisturized, particularly for CO2 adsorption. Thus, CO2adsorption of the polymeric sorbent may increase at higher relative humidity (RH). For example, in the range between 30 % and 70% RH, the sorbent can adsorb significantly more CO2compared to dry conditions. Above 70 % RH, water may start competing for adsorption sites in the sorbent, reducing the efficiency of CO2capture.

[0134]

[0135] The water distribution system may be located within the cooling unit of the desorption assembly. The water distribution system may comprise at least one nozzle, and a liquid (water) distribution channel, and one or more pipeline(s). The liquid distribution system may be a dual -phase system, for both steam and water. In some embodiments, the water distribution system comprises a plurality of nozzles. The water distribution system may comprise at least one sensor, a moisture control mechanism and a feedback control. In some embodiments, the nozzle(s) may be a spray nozzle and may optionally comprise a spray plate. The spray plates may be used for precision jetting of the liquid and / or gases and may be mounted below the nozzle. The spray nozzle may be inserted in the liquid (water) distribution channel. The nozzles further can be selected from atomizing nozzles, fine mist nozzles, ultrasonic spray nozzles.

[0136] The moving bed desorption assembly is preferably incorporated into a system for separation of carbon dioxide from ambient air, as shown in Fig. 6. The system for separation of carbon dioxide from ambient air comprises the moving bed desorption assembly as described above, and at least one moving bed adsorption assembly. In the moving bed desorption assembly, the sorbent, which is preferably solid, particulate sorbent is conveyed through pre-heating unit (where its temperature is raised), desorption zone (for releasing CO2), and cooling unit (for cooling the regenerated sorbent). Further, each of the pre-heating unit, desorption chamber and the cooling unit each comprise a separate low-pressure (vacuum) enclosure, as shown in Fig. 5.

[0135]

[0137] With reference to Fig. 6, the system 100 for separation of carbon dioxide (CO2) from ambient air (hereinafter referred to as “the system”) comprise at least one moving bed adsorption assembly 40 and at least one moving bed desorption assembly 42. All of the components of the moving bed desorption assembly 42 shown in Fig. 4 and Fig. 5 are likewise incorporated into the configuration shown in Fig. 6.The moving bed desorption assembly 42 is configured to regenerate the sorbent by releasing the carbon dioxide from sorbent and comprises a pre-heating unit 10, a desorption chamber 20 for removing CO2from a CO2- enriched (laden) sorbent, and a cooling unit 30. The moving bed desorption assembly 42 also comprises a feed inlet 15 for introduction of CO2-enriched sorbent in communication with the transportation system, and a discharge outlet 12 for removing regenerated sorbent, also in communication with the transportation system 11 , and at least one fluid outlet for release of one or more fluids. Further, the moving bed desorption assembly comprises a condenser 35 for coolingthe watervapor.

[0136]

[0138] Further, the moving bed adsorption assembly 40 and the moving bed desorption assembly 42 are in communication with each other by means of transportation system, preferably a mechanical transportation system. The system 100 for separation of carbon dioxide (CO2) from ambient air comprises at least one moving bed adsorption assembly 40, including an adsorption chamber configured to capture carbon dioxide from a gas stream (air , ambient air), and comprising a plurality cartridges, at least one air inlet, at least one gas outlet(s), at least one sorbent feed inlet(s), and at least one sorbent discharge outlet(s). The system 100 may comprise two or more moving bed adsorption assemblies 40.

[0137]

[0139] The transportation system 11 , as previously described, is a mechanical system, designed to efficiently convey solid sorbent material between the moving bed adsorption assembly 40 and the moving bed desorption assembly 42. The transportation system(s) can be selected from a mechanical conveying system, such as a disc-and-chain conveyor or a bucket conveyor. For example, the mechanical conveying system may comprise a series of containers attached to a belt or chain, which moves in a continuous loop. The present invention may provide a reversible adsorption of the gaseous component (CO2) with a very low-pressure drop of the gas stream and with a very high mass transfer rate between the gas phase and the surface of the sorbent, and release of the CO2 form the sorbent.

[0138]

[0140] The system 100 for separation of carbon dioxide (CO2) may further comprise process equipment which may include one or more of: pumps, sensors, valves, condensers, control units, and conduits.

[0139]

[0141] Each unit within the desorption assembly may comprise a plurality of pillow-plate heat exchangers. Each of the first, second and third pillow-plate heat exchangers comprise two pillow plates attached to each other, preferably by welding, and adjacent heat exchangers within each unit of the desorption assembly are positioned in an offset configuration.

[0140]

[0142] The heat transfer fluid circulating in the closed loop within the desorption assembly absorbs heat from the regenerated sorbent in the cooling unit that is used to pre-heat the CO2-loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2- loaded sorbent in the pre-heating unit is utilized to cool the regenerated sorbent within the cooling unit.

[0141]

[0143] Additionally, the pre-heating and cooling units play a crucial role in maintaining the continuous operation of the desorption chamber, enabling it to function without the need for periodic venting.

[0142]

[0144] In a preferred embodiment, there is provided a moving bed desorption assembly for recovery of sorbent loaded with CO2, where the CO2was captured from ambient air, comprising: a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2- loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and a plurality of first heat exchangers; a pre-heating unit configured to pre-heat the loaded sorbent and comprising a plurality of second heat exchangers, and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent comprising a plurality of third heat exchangers, and being in communication with the discharge outlet of the desorption chamber, wherein the plurality of first, second and third heat exchangers are pillow-plate heat exchangers, wherein within each unit (pre-heating unit, desorption chamber, cooling unit) of the desorption assembly, adjacent pillow-plate heat exchangers are arranged offset from each other. Furthermore, the heat transfer fluid flowing within each of the plurality of first, second and third pillow plate heat exchangers is water. Further, the pillow plate pitch d1 between two adjacent pillow plate heat exchangers (A1, A2) is between 10 mm and 14 mm. In addition, the pillow plates of each of the first, second and third heat exchangers may have a thickness (d3) of the welded parts of the pillow plates in the range of from 0.5 mm to 20 mm, or of from 0.5 mm to 10 mm.

[0145] The heat transfer fluid may circulate within a closed loop, where it initially absorbs heat from the regenerated sorbent in the cooling unit, as shown in FIG. 1 . This heat is then utilized to pre-heat the CO2-loaded sorbent in the pre-heating unit to a first temperature. Following this, the heat transfer fluid, after being cooled by its interaction with the CO2-loaded sorbent in the pre-heating unit, is redirected back to the cooling unit to aid in the cooling of the regenerated sorbent. As the heat transfer fluid flows through the cooling unit, it absorbs thermal energy from the hot regenerated sorbent. This process reduces the temperature of the sorbent, effectively cooling it down for reuse in the CO2capture process. Upon exiting the cooling unit, the heat transfer fluid, which has increased in temperature due to the thermal absorption from the regenerated sorbent, acts as a thermal carrier.

[0143]

[0146] Thus, there is provided method for regenerating CO2-loaded sorbent within the moving bed desorption assembly, the method comprising the following steps: a) introducing a CO2-loaded sorbent in a pre-heating unit of the moving bed desorption assembly, b) heating the CO2-loaded sorbent within the pre-heating unit to elevate its temperature from starting temperature in the range of from -20°C to 50°C to a first temperature through heat exchange with a heat transfer fluid, wherein the first temperature is higher than the starting temperature, c) transferring the pre-heated sorbent into a desorption chamber, and adjusting the temperature of the CO2-loaded sorbent to a second temperature, while applying vacuum of from 20 to 400 mbar absolute, wherein the second temperature is higher than the first temperature, d) releasing the CO2from the sorbent thereby regenerating the sorbent for subsequent CO2capture cycles, e) cooling the regenerated sorbent in a cooling unit to a third temperature through heat exchange with the heat transfer fluid, by transferring heat to the heat transfer fluid, wherein the third temperature is lower than the second temperature and equal or higher than the first temperature, f) circulating the heat transfer fluid between the cooling and pre-heating units in a closed loop for heat recovery. Further, the heat transfer fluid circulating in the closed loop absorbs heat from the regenerated sorbent in the cooling unit and subsequently transfers heat to pre-heat the CO2-loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2-loaded sorbent in the pre-heating unit is utilized to cool the regenerated sorbent within the cooling unit.

[0144]

[0147] The circulation of the heat transfer fluid between the cooling and pre-heating units in a closed loop enables efficient heat recovery. Heat extracted from the pre-heating unit during sorbent preheating is transferred to the cooling unit during sorbent regeneration, reducing energy consumption and enhancing overall system efficiency.

[0145]

[0148] Further, the first temperature can be between 40°C and 75°C, 45°C and 75°C, 45°C and 70°C, 50°C and 70°C, 55°C and 60°C, more preferably 55°C.

[0149] The second temperature can be between 80°C and 150°C, 80°C and 130°C, 85°C and 125°C, 90°C and 120°C, 90°C and 105°C, preferably between 90°C and 100°C.

[0146]

[0150] The third temperature can be between 40°C and 70°C, preferably 50°C and 70°C, more preferably 50°C and 60°C, even more preferably 55°C and 60°C.

[0147]

[0151] In an embodiment, the starting temperature is in the range of from -10°C to 45 °C, -5°C to 40°C, 0°C to 45°C, 5 °C to 45°C, 10°C to 45°C, 10°C to 40°C, 15°C to 35°C, 15°C to 25°C.

[0148]

[0152] In a preferred embodiment, there is provided method for regenerating CO2-loaded sorbent within the moving bed desorption assembly, the method comprising the following steps: a) introducing a CO2-loaded sorbent in a pre-heating unit of the moving bed desorption assembly, b) heating the CO2-loaded sorbent within the pre-heating unit to elevate its temperature from starting temperature in the range of from 10°C to 40°C to a first temperature of from 45°C to 70°C through heat exchange with a heat transfer fluid, c) transferring the pre-heated sorbent into a desorption chamber, and adjusting the temperature of the CO2-loaded sorbent to a second temperature of from 85°C to 105°C, while applying vacuum in the range for from 40 mbar absolute to 60 mbar absolute, d) releasing the CO2from the sorbent thereby regenerating the sorbent for subsequent CO2capture cycles, e) cooling the regenerated sorbent in a cooling unit to a third temperature of from 55°C to 60°C through heat exchange with the heat transfer fluid, by transferring heat to the heat transfer fluid, f) circulating the heat transfer fluid between the cooling and pre-heating units in a closed loop for heat recovery. Further, the heat transfer fluid circulating in the closed loop absorbs heat from the regenerated sorbent in the cooling unit and subsequently transfers heat to pre-heat the CO2-loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2-loaded sorbent in the preheating unit is utilized to cool the regenerated sorbent within the cooling unit.

[0149]

[0153] The heat transfer fluid circulating in the closed loop absorbs heat from the regenerated sorbent in the cooling unit and subsequently transfers heat to pre-heat the CO2-loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2-loaded sorbent in the pre-heating unit is utilized to cool the regenerated sorbent within the cooling unit.

[0150]

[0154] The thermal energy gained by the heat transfer fluid is quantifiable by the specific heat capacity of the fluid and the mass flow rate, according to the equation:

[0151]

[0155] Q=m Cp AT ,

[0152]

[0156] where Q - heat transferred, m - mass flow rate, Cp- specific heat capacity, and AT - temperature change of the heat transfer fluid.

[0153]

[0157] For example, the specific heat capacity of water is approximately 4.18J / g°C at 20 °C.

[0158] The flow rate of the heat transfer fluid can be between 1 l / min to 100 l / min, 1 l / min to 70 l / min, 1 l / min to 50 l / min, 1 l / min to 40 l / min, 2 l / min to 30 l / min, 2 l / min to 20 l / min, 2 l / min to 10 l / min, 2 l / min to 5 l / min, 3 I min to 4 l / min.

[0154]

[0159] In a preferred embodiment the flow rate of the water as a heat transfer fluid can be between 3 l / min to 4 l / min, or between 3 l / min and 3.5 l / min.

[0155]

[0160] Example 1

[0156]

[0161] During use of the desorption assembly of FIG. 3, the heat transfer fluid, i.e., water, in the closed loop absorbed heat from the regenerated sorbent in the cooling unit, raising its temperature to a range between 55°C and 60°C. This hot water was then transferred to the pre-heating unit, where it efficiently transferred thermal energy to the CO2-loaded sorbent, heating it to a temperature between 50°C and 60°C. Then the cooled water, returned to a range of 20°C to 30°C, is pumped back to the cooling unit to complete the closed-loop heat exchange and cool the regenerated sorbent. The flow rate of the water was 3 l / min. The sorbent was an amine- functionalized ion exchange resin sorbent in form of beads.

[0157]

[0162] Example 2

[0158]

[0163] During use of the desorption assembly of FIG. 1 , in the pre-heating unit the starting temperature of the CO2- loaded sorbent was elevated from a range of from 5°C to 30°C to a target first temperature range between 55°C and 60°C. The pre-heating load was 7.11 kW. Subsequently, this pre-heated sorbent was conveyed into the vacuum chamber, where under vacuum of 50 mbar absolute, it was further heated to reach a second temperature between 90°C and 105°C.

[0159]

[0164] The CO2was discharged along with other fluids through the at least one fluid outlet of the desorption chamber. The now regenerated sorbent was then directed to the cooling unit, where its temperature was reduced to fall within the range of 50°C to 60°C (corresponding to the third temperature), thereby preparing it for reuse in the continuous cycle of adsorption and regeneration. The cooling load was 7.11 kW.

[0160]

[0165] Sorbent

[0161]

[0166] Direct Air Capture (DAC) systems typically employ sorbents in either liquid or solid form to capture CO2from the atmosphere. Solid sorbent-based technology offers a versatile solution for carbon dioxide direct air capture, where CO2concentrations range from approximately 400 to 1000 ppm.

[0162]

[0167] Typical sorbents used in this context are solid materials known for their high surface area-to- volume ratios, crucial for efficient adsorption processes. These sorbents include a variety of inorganic and organic polymeric substances such as zeolites, alumina, silica, silica-alumina combinations, and various organic polymers. Specifically designed to maximize interaction with the gas stream, these materials are often formed into lightweight and porous beads or membranes.

[0163]

[0168] Porous sorbents are characterized by large surface areas, but only weak adsorption sites, thereby lacking sufficient capacity for CO2under ultra-low CO-2concentrations. To enhance the sorption potential for low-pressure CO2, amine functional groups have been incorporated into highly porous sorbent materials. Sorbents featuring primary amino groups are particularly potent for efficient CO2capture.

[0164]

[0169] In particular, amine functionalized solid sorbents are used for CO2direct air capture, due to their affinity to CO2, fast kinetics, high selectivity and long-term stability under ultra-low CO2concentration and humid conditions.

[0165]

[0170] Amine-functionalized solid adsorbents for CO2capture are based on support, often having a large surface area to which functional groups are attached by techniques such as amine based functionalization or amination. The adsorbent material may be based on a polystyrene material, preferably cross-linked polystyrene material and most preferably poly(styrene-co-divinylbenzene), which is at least partially functionalized to or contains alkylbenzylamine moieties, preferably a- methylbenzylamine moieties, preferably throughout the material or at least or only on its surface.

[0166]

[0171] Preferably, in the present invention, the sorbent can be a polymeric solid sorbent in form of beads, preferably the sorbent can be an amine-functionalized solid adsorbent, more preferably a primary amine-functionalized polymeric ion-exchange resin.

[0167]

[0172] In a preferred embodiment, the amine-functionalized adsorbent material used for direct CO2capture can be an amine functionalized ion exchange resin and may be in spherical bead form.

[0168]

[0173] The sorbent can have a primary amino functionality at a total capacity of at least 2.0 eq. / I, a surface area (BET) in the range of from 25 to 75 m 2 / g, and an average pore diameter of 1 to 200 nm.

[0169]

[0174] In an embodiment of the present invention, the chosen sorbent may comprise granular or particulate material characterized by a particle size (D50) ranging from approximately 0.1 mm to 5 mm, preferably 0.5 mm to 3 mm, more preferably 0.5 mm to 2 mm. The chosen particle size of the sorbent is generally small enough to provide a large surface area for adsorption but large enough to avoid excessive pressure drops and thus less energy consuming.

[0170]

[0175] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

Claims1 . A moving bed desorption assembly for recovery of sorbent loaded with CO2comprising: a desorption chamber for removing CO2from a CO2-loaded sorbent comprising a feed inlet for introduction of CO2-loaded sorbent, and a discharge outlet for removing regenerated sorbent, and at least one fluid outlet for release of one or more fluids, and at least one first heat exchanger, a pre-heating unit configured to pre-heat the CO2-loaded sorbent and being in communication with the feed inlet of the desorption chamber, and a cooling unit configured to cool the regenerated sorbent and being in communication with the discharge outlet of the desorption chamber.

2. The moving bed desorption assembly according to claim 1 , wherein the desorption chamber is a low-pressure enclosure.

3. The moving bed desorption assembly according to claim 2, wherein the low-pressure enclosure is a vacuum chamber configured to operate under vacuum in the ranging from 20 mbar absolute to 400 mbar absolute, preferably in the range of from 40 mbar absolute to 60 mbar absolute and a second temperature in the range of from 80°C to 150°C.

4. The moving bed desorption assembly according to any one of claims 1 to 3, wherein the at least one first heat-exchanger is a pillow-plate heat exchanger.

5. The moving bed desorption assembly according to any one according to claims 1 to 4, wherein the desorption chamber comprises a plurality of pillow-plate heat exchangers.

6. The moving bed desorption assembly according to any one of claims 1 to 5, wherein the preheating unit comprises at least one second heat exchanger configured to pre-heat the CO2-loaded sorbent to a first temperature.

7. The moving bed desorption assembly according to claim 6, wherein the first temperature is in the range of from 40°C to 75°C.l8. The moving bed desorption assembly according to claim 6 or 7, wherein the at least one second heat exchanger is a pillow plate heat-exchanger.

9. The moving bed desorption assembly of any one of claims 1 to 8, wherein the cooling unit comprises at least one third heat exchanger configured to cool recovered sorbent to a third temperature.

10. The moving bed desorption assembly according to claim 9, wherein the third temperature is in the range of from 40°C to 70°C, preferably 50°C to 60°C.11 . The moving bed desorption assembly according to any one of the preceding claims, wherein each of the pre-heating unit, desorption chamber and the cooling unit each comprise a separate low-pressure enclosure.

12. The moving bed desorption assembly according to any one of the preceding claims, wherein both the pre-heating and the cooling units are configured to operate at low pressure, ranging from 20 mbar absolute to 400 mbar absolute.

13. The moving bed desorption assembly according to any one of claims 9 to 12, wherein the at least one third heat exchanger is a pillow plate heat-exchanger.

14. The moving bed desorption assembly according to any one of the preceding claims, wherein each of the first, second and third pillow plate heat exchangers comprises two plates welded together forming a series of pillow-like indentations on both sides of the plates, wherein the series of pillow-like indentations have internal channels for heat transfer fluid to flow th rough.

15. The moving bed desorption assembly according to any one of the preceding claims, wherein the pre-heating unit, the desorption chamber, and the cooling unit each comprise a plurality of the first, second, and third heat exchangers, respectively.

16. The moving bed desorption assembly according to any one of the preceding claims, wherein two adjacent first, second or third pillow-plate heat exchangers are configured to form an external channel for the passing of CO2-loaded sorbent.

17. The moving bed desorption assembly according to claim 15, wherein two adjacent pillowplate heat exchangers, either from the first, second, or third pillow-plate heat exchangers, are conjoined in an offset alignment.

18. The moving bed desorption assembly according to claim 16, wherein a pillow plate pitch (di ) defined as distance measured between the welded parts of two adjacent pillow plate heat exchangers is between 5 mm and 30 mm.

19. The moving bed desorption assembly according to any one of claims 15 to 17, wherein a thickness (d3) of the welded parts of the pillow plates is in the range of from 0.5 mm to 20 mm.

20. The moving bed desorption assembly according to any one of claims 1 to 18, wherein the desorption chamber comprises at least one valve configured to regulate the flow rate of the sorbent.21 . The moving bed desorption assembly according to any one of claims 1 to 18, wherein the cooling unit further comprises liquid distribution system, preferably water distribution system.

22. The moving bed desorption assembly according to any one of claims 1 to 20, wherein the water distribution system comprises at least one nozzle, preferably spray nozzle.

23. The moving bed desorption assembly according to claim 19, further comprising at least one conduit system, featuring at least one pump, configured to cycle the heat transfer fluid between the pre-heating unit and the cooling unit.

24. The moving bed desorption assembly according to claim 20, wherein the heat transfer fluid is a liquid, preferably water.

25. The moving bed desorption assembly according to any one of the preceding claims, wherein the sorbent is a polymeric solid sorbent in form of beads.

26. The moving bed desorption assembly according to any one of the preceding claims , wherein the polymeric solid sorbent is an amine-functionalized polymeric ion-exchange resin, more preferably a primary amine-functionalized polymeric ion-exchange resin.

27. The moving bed desorption assembly according to any one of the preceding claims, further comprises a transportation system configured to transport a regenerated sorbent from the bottom of the desorption assembly to the top of the adsorption assembly and vice versa.

28. A method for regenerating CO2-loaded sorbent within a moving bed desorption assembly according to any one of claims 1 to 23 comprising the following steps: a) introducing a CO2-loaded sorbent in a pre-heating unit of the moving bed desorption assembly, b) heating the CO2-loaded sorbent within the pre-heating unit to elevate its temperature from starting temperature in the range of from -20°C to 50°C to a first temperature through heat exchange with a heat transfer fluid, wherein the first temperature is higher than the starting temperature, c) transferring the pre-heated sorbent into a desorption chamber, and adjusting the temperature of the CO2-loaded sorbent to a second temperature, while applying vacuum of from 20 to 400 mbar absolute, wherein the second temperature is higher than the first temperature, d) releasing the CO2from the sorbent thereby regenerating the sorbent for subsequent CO2capture cycles, e) cooling the regenerated sorbent in a cooling unit to a third temperature through heat exchange with the heat transfer fluid, by transferring heat to the heat transfer fluid, wherein the third temperature is lower than the second temperature and equal or higher than the first temperature, f) circulating the heat transfer fluid between the cooling and pre-heating units in a closed loop for heat recovery.

29. The method for regenerating CO2-loaded sorbent according to Claim 28, wherein the heat transfer fluid circulating in the closed loop absorbs heat from the regenerated sorbent in the cooling unit and subsequently transfers heat to pre-heat the CO2-loaded sorbent in the pre-heating unit, while the same heat transfer fluid upon cooling by the CO2-loaded sorbent in the pre-heating unit is utilized to cool the regenerated sorbent within the cooling unit.

30. The method for regenerating CO2-loaded sorbent according to claim 28 or 29, wherein the starting temperature is in the range of from 5°C to 50°C, preferably 10°C to 40°C, more preferably 15°C to 35°C.31 . The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 30, wherein the first temperature is in the range of from 40°C to 75°C, more preferably 45°C to 65°C.

32. The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 31 , wherein the second temperature is in the range of from 80°C to 150°C.

33. The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 32, wherein the second temperature is in the range of from 85°C to 130°C, more preferably 90 °C to 120°C, even more preferably 90°C to 110°C.

34. The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 33, wherein the third temperature is in the range of from 40°C to 70°C.

35. The method for regenerating CO2-loaded sorbent according to claim 34, wherein the third temperature is in the range of from 50°C to 60°C.

36. The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 35, wherein the heat transfer fluid is liquid, preferably water.

37. The method for regenerating CO2-loaded sorbent according to any one of claims 28 to 36, wherein the vacuum is in the range of from 40 mbar absolute to 60 mbar absolute.

38. A system for separation of carbon dioxide from ambient air comprising a moving bed adsorption assembly for capturing CO2from ambient air comprising an adsorption chamber configured to capture carbon dioxide from a gas stream, and comprising a plurality of cartridges, at least one air inlet, at least one gas outlet(s), at least one sorbent feed inlet(s), and at least one sorbent discharge outlet(s), and a moving bed desorption assembly according to any one of the preceding claims.

39. The system according to claim 38, further comprising a transportation system configured to transport a CO2-loaded sorbent from the bottom of the adsorption assembly to the top of the desorption assembly and to return the regenerated sorbent from the bottom of the desorption assembly to the top of the adsorption assembly.

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