A self-supporting carbon dioxide capture monolith

Abstract

The application discloses a self-supporting carbon dioxide capture monolith structure, belonging to the field of direct air capture (DAC) technology, and solves the problems of large pressure drop, low heat transfer efficiency and the need for additional fixing structure of a traditional powder adsorbent. The monolith structure comprises a composite matrix, the composite matrix containing an adsorbent material, a gradient heat transfer layer and a multi-channel structure: the adsorbent material is composed of clinoptilolite, kaolin and a methyl cellulose binder; the gradient heat transfer layer is formed by depositing copper powder in the adsorbent material, the copper content increasing from the outer wall to the core direction, realizing directional heat transfer of carbon dioxide adsorption-regeneration cycle; and the multi-channel structure penetrates through the composite matrix, providing a low pressure drop air flow path. The monolithic design has self-supporting capability, does not need additional fixing structure, can integrate a heating element to assist regeneration of the adsorbent material, can efficiently complete adsorption-regeneration cycle, provides a low pressure drop carbon dioxide adsorption capture solution for the DAC field, the material is natural, non-toxic and easy to handle, and has outstanding application value.

Description

Technical Field

[0001] This invention relates to direct air capture (DAC) technology, and in particular to a self-supporting monolithic structure for capturing carbon dioxide. Background Technology

[0002] Currently, applied methods for removing carbon dioxide from the air using regenerable (recyclable) direct air capture (DAC) technology include the use of liquid or solid adsorbents with an affinity for carbon dioxide. Adsorbents typically capture carbon dioxide in two ways: chemisorption and physisorption. Chemisorption forms stronger chemical bonds, thus requiring more energy for regeneration; while physisorption typically utilizes weaker forces such as van der Waals forces, requiring less energy for regeneration. In liquid adsorbent systems, the adsorbent is potassium hydroxide (KOH) or sodium hydroxide (NaOH), which works by converting gaseous carbon dioxide into carbonates, followed by high-temperature regeneration (approximately 900°C) to release carbon dioxide for further treatment. Solid adsorbents can be used directly or coated with additional chemicals such as amines. Regeneration of solid adsorbents (to release carbon dioxide) can be achieved through heating (approximately 80°C–above 200°C), pressurization, vacuuming, or a combination of these methods. Liquid adsorbents, due to their inherent properties, are prone to evaporation, thus losing their adsorption capacity and requiring continuous replenishment. Solid adsorbents are typically placed in packed beds and can be in the form of particles, powders, or spheres. They can function independently or serve as a carrier for coating chemicals.

[0003] The main problems with these two methods are: high energy consumption for adsorbent regeneration, adsorbent degradation / oxidation, cost or potential synthesis issues of the adsorbent, toxicity, and end-of-life disposal of the adsorbent (especially when using toxic adsorbents). In the prior art, only solid adsorbents can potentially be molded into a monolithic structure, but such information is not disclosed in applied solutions. It is highly likely that these monolithic structures employ coating designs containing additional chemicals, thus presenting end-of-life disposal issues, rather than the independent material proposed in this invention.

[0004] Effective heating is essential for the periodic regeneration (cycling) of solid adsorbents, and it is particularly challenging for non-uniform designs due to the small contact area between the particles and the coating structure, resulting in low heat transfer efficiency. Traditional heating methods (conduction) may include resistance heaters, which need to transfer heat to the adsorbent. Ideally, the heat transfer should be uniform and should not create hot spots that could lead to degradation, instability, or oxidation of the adsorbent or its coating.

[0005] Because the atmospheric carbon dioxide concentration is low (approximately 425 ppm), a large flow of air is required to capture a certain amount of carbon dioxide through the adsorbent material. The energy demand for this airflow is primarily influenced by the pressure drop of the adsorbent medium; therefore, a denser packing of the adsorbent results in a higher energy demand than an adsorbent with a smaller pressure drop. This presents a significant challenge in balancing the adsorbent's contact area, heat transfer, and pressure drop.

[0006] In existing technologies, the heat exchanger (heating / cooling device) and the adsorbent material are separate components. This requires expensive and complex systems to properly heat or cool (regulate) the adsorbent, which is detrimental to modularity and requires specific engineering implementation. Furthermore, this design can create hot spots, leading to adsorbent degradation, especially for coated solid adsorbents. Additionally, these external heat exchangers occupy space that could be used for the adsorbent, reducing the contact area and volume available for carbon dioxide adsorption within the contactor cavity. However, for efficient heating, the solid particles need to be neatly aligned, resulting in a high pressure drop, leading to pressure loss and higher energy demands. The challenge of facilitating maintenance while simultaneously securing the adsorbent often necessitates additional structures within the contactor, thus occupying space.

[0007] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] The main objective of this invention is to overcome the deficiencies in the aforementioned background technology and provide a self-supporting carbon dioxide capture structure.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A self-supporting monolithic carbon dioxide capture structure includes:

[0011] Composite matrix, comprising:

[0012] -The adsorbent material (1) contains clinoptilolite, kaolin and methylcellulose binder;

[0013] - Gradient heat transfer layer, formed by copper powder deposition in adsorption material, with copper content increasing from the outer wall to the core of the overall structure, to achieve directional heat transfer in carbon dioxide adsorption-regeneration cycle;

[0014] - A multi-channel structure (2) extends through the composite matrix to provide a low-pressure-drop airflow path.

[0015] Furthermore, the gradient heat transfer layer includes:

[0016] The static heat transfer zone includes:

[0017] -The outer wall static region (6) extends continuously or is distributed at intervals along the circumference, located in the outermost boundary region of the overall structure, and has a first constant copper ratio;

[0018] - The intermediate static region (3) extends continuously or is distributed at intervals along the circumference and is located inside the outer wall static region (6), and has a second constant copper ratio;

[0019] - The inner circumferential static region (4) extends continuously or is distributed at intervals along the circumference and is located inside the intermediate static region (3), and has a third constant copper ratio;

[0020] Wherein, the first constant copper ratio < the second constant copper ratio < the third constant copper ratio;

[0021] The dynamic heat transfer zone (5) extends radially from the outer wall static zone (6) toward the center of the overall structure; and includes, in sequence along the radial direction:

[0022] -Outer terminal area (5a), adjacent to the outer wall static area (6);

[0023] - The intermediate sub-region (5b) is adjacent to the intermediate static region (3) and the inner peripheral static region (4);

[0024] -Inner terminal area (5c);

[0025] The copper ratio satisfies the following condition: the outer terminal area (5a) < the inner terminal area (5c) < the intermediate sub-region (5b).

[0026] Furthermore, the radial distance from the inner edge of the outer wall static zone (6) to the center of the overall structure is defined as follows:

[0027] -The intermediate static region (3) is located at 1 / 3 of the radial distance;

[0028] - The inner circumferential static region (4) is located at 2 / 3 of the radial distance.

[0029] Furthermore, the copper powder ratio of the gradient heat transfer layer is: the first constant copper ratio <5%, and the third constant copper ratio ≤20%.

[0030] Furthermore, the raw materials of the composite matrix include, by weight, 70-85 parts of clinoptilolite, 5-20 parts of kaolin, and 1-15 parts of methylcellulose binder solution.

[0031] Furthermore, the cross-sectional shape of the multi-channel structure includes any one of hexagonal, circular, triangular, or organically generated shapes.

[0032] Furthermore, it also includes an integrated heating element (7), which is located inside the outer wall of the overall structure and is thermally coupled to the gradient heat transfer layer.

[0033] Furthermore, the integrated heating element is a nickel-chromium alloy wire with an enamel coating, which is meanderingly embedded in the outer wall of the overall structure, and its terminals extend to the outer wall surface to achieve independent temperature control or daisy chain connection.

[0034] Furthermore, the methylcellulose binder is selected from methylcellulose (MC), carboxymethylcellulose (CMC), or hydroxypropyl methylcellulose (HPMC).

[0035] Furthermore, the overall structure is hexagonal.

[0036] Multiple integral structures can be stacked and rotated in a staggered manner to mix airflow.

[0037] Furthermore, it is manufactured by extrusion molding or 3D printing processes, and the gradient heat transfer layer is achieved by partitioned deposition of copper powder.

[0038] The present invention has the following beneficial effects:

[0039] This invention provides a self-supporting carbon dioxide capture structure that solves the problems of large pressure drop and low heat transfer efficiency in traditional powder adsorbent structures.

[0040] The important innovative design of this invention includes three aspects: First, a stable and self-supporting overall structure capable of capturing carbon dioxide is achieved through a specific combination of materials; second, the materials and internal structure are optimized, significantly enhancing the heating / cooling transfer capability; and third, by setting a gradient heat transfer layer in a precise pattern (e.g., changing the proportion of copper powder added), specific heat transfer behavior is achieved within the structure, giving the material a highly modular characteristic that can be flexibly adjusted for different regions and systems.

[0041] The self-supporting integral structure of the preferred embodiment of the present invention integrates a heat transfer layer and a heating element. By integrating the heat exchange layer into the structure and using specific materials and adhesives, an integrated heating / cooling transfer effect is achieved, effectively overcoming the shortcomings of traditional technologies.

[0042] Compared with traditional technologies, the embodiments of this invention exhibit significant advantages in several aspects: A stable heat transfer channel is constructed by modifying the copper powder ratio in a specific manner, and the copper ratio is adjusted by layering materials in specific areas of the overall structure, thereby enhancing the internal heat transfer (heating / cooling) effect through the metallic lattice properties of copper; the integrated heating element is embedded in the outer wall, simplifying the manufacturing and recycling process; the heat transfer layer is formed by directly depositing metal particles, and the arrangement and treatment of the heating wire avoids the delamination (surface peeling) problem that easily occurs in embedded metal plates or heat sinks, and the solution is simpler with fewer manufacturing processes; the integrated design with channels, combined with multi-shaped channel structures, significantly reduces the pressure drop when airflow passes through the adsorption material, while airflow mixing is achieved through the stacking and rotation of multiple integrated structures; by optimizing the ratio of clinoptilolite, kaolin, and methylcellulose binders in the composite matrix, a significant decrease in carbon dioxide adsorption capacity is avoided while integrating the heat transfer structure; the combination of clinoptilolite, kaolin, and methylcellulose dispersions gives the overall structure self-supporting capabilities, allowing it to withstand weight and airflow impact without additional fixing structures.

[0043] This invention has outstanding value in the field of direct air capture (DAC): its self-supporting integral structure provides a solution for low-pressure-drop carbon dioxide adsorption; the carefully distributed integrated heat transfer layer and heating element for adsorbent material regeneration within the core ensure an efficient carbon dioxide adsorption-regeneration cycle; the selected materials not only guarantee excellent adsorption performance but also reduce environmental impact due to their natural non-toxic properties; and the hexagonal and other structural designs allow for flexible combination of multiple integral structures, integrating them into contactors of different shapes in series, parallel, or series-parallel combinations, greatly improving application flexibility.

[0044] Other beneficial effects of the embodiments of the present invention will be further described below. Attached Figure Description

[0045] Figure 1 This is a hexagonal self-supporting integral structure according to an embodiment of the present invention.

[0046] Figure 2 The hexagonal self-supporting integral structure according to an embodiment of the present invention shows an integrated heating element within the wall.

[0047] Figure 3 This is a view of the copper deposition region within a hexagonal self-supporting monolithic structure according to an embodiment of the present invention.

[0048] Figure 4 This is a view of the copper deposition region within a hexagonal self-supporting monolithic structure according to an embodiment of the present invention, showing an integrated heating element within the wall.

[0049] Figure 5 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 1 .

[0050] Figure 6 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 2 .

[0051] Figure 7 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 3 .

[0052] Figure 8 This is a diagram showing the interval distribution of the static area on the outer wall according to another embodiment of the present invention (copper powder is deposited in part of the outer wall area).

[0053] Figure 9 This is a different view according to another embodiment of the present invention.

[0054] Figure 10 A schematic diagram of a high-density resin mold used for fabricating a hexagonal monolithic structure. Detailed Implementation

[0055] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0056] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0057] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0059] This invention aims to overcome the problems of powder adsorbent structure—high pressure drop and low heat transfer efficiency through the adsorbent. To this end, it provides a self-supporting material with an integral design. The material achieves directional and efficient heat transfer through a gradient heat transfer layer, while significantly reducing pressure drop through a multi-channel structure. It also has self-supporting capabilities and does not require additional fixing structures.

[0060] See Figures 1 to 9 This invention provides a self-supporting carbon dioxide capture structure, including a composite matrix and an optional integrated heating element 7. The composite matrix comprises an adsorbent material 1, a gradient heat transfer layer, and a multi-channel structure 2. The adsorbent material 1 contains clinoptilolite, kaolin, and a methylcellulose binder. The gradient heat transfer layer is formed by depositing copper powder into the adsorbent material 1, with the copper content increasing from the outer wall to the core of the structure to achieve directional heat transfer in the adsorption-regeneration cycle. The multi-channel structure 2 penetrates the composite matrix to provide a low-pressure-drop airflow path. The integrated heating element 7 is disposed within the outer wall of the structure. Optionally, the structure further includes the integrated heating element 7, disposed within the outer wall of the structure, and thermally coupled to the gradient heat transfer layer.

[0061] See Figures 3 to 4 In some embodiments, the gradient heat transfer layer includes a static heat transfer zone and a dynamic heat transfer zone 5. The static heat transfer zone includes an outer wall static zone 6, a middle static zone 3, and an inner circumferential static zone 4. The outer wall static zone 6 extends continuously or is spaced apart along the circumference and is located at the outermost boundary region of the overall structure, having a first constant copper ratio. The middle static zone 3 extends continuously or is spaced apart along the circumference and is located inside the outer wall static zone 6, having a second constant copper ratio. The inner circumferential static zone 4 extends continuously or is spaced apart along the circumference and is located inside the middle static zone 3, having a third constant copper ratio. The first constant copper ratio < the second constant copper ratio < the third constant copper ratio. The dynamic heat transfer zone 5 extends radially from the outer wall static zone 6 toward the center of the overall structure; the dynamic heat transfer zone 5 includes, in radial order, an outer terminal zone 5a, an intermediate sub-zone 5b, and an inner terminal zone 5c, wherein the outer terminal zone 5a is adjacent to the outer wall static zone 6, and the intermediate sub-zone 5b is adjacent to the intermediate static zone 3 and the inner peripheral static zone 4; wherein the copper ratio satisfies: outer terminal zone 5a < inner terminal zone 5c < intermediate sub-zone 5b.

[0062] In some embodiments, the radial distance from the inner edge of the outer wall static area 6 to the center of the overall structure is taken as the reference point, the middle static area 3 is located at 1 / 3 of the radial distance, and the inner peripheral static area 4 is located at 2 / 3 of the radial distance.

[0063] In some embodiments, the copper powder ratio of the gradient heat transfer layer is: the first constant copper ratio < 5%, and the third constant copper ratio ≤ 20%.

[0064] In some embodiments, the raw materials of the composite matrix include, by weight, 70-85 parts of clinoptilolite, 5-20 parts of kaolin, and 1-15 parts of methylcellulose binder solution.

[0065] In some embodiments, the cross-sectional shape of the multi-channel structure 2 includes any one of hexagonal, circular, triangular, or organically generated shapes.

[0066] See Figure 2 and Figure 4 In some embodiments, the integrated heating element 7 is a nickel-chromium alloy wire with an enamel coating, which is meanderingly embedded in the outer wall of the overall structure, and its terminals extend to the outer wall surface to achieve independent temperature control or daisy chain connection.

[0067] In some embodiments, the methylcellulose binder is selected from methylcellulose (MC), carboxymethylcellulose (CMC), or hydroxypropyl methylcellulose (HPMC).

[0068] See Figures 1 to 9 In some embodiments, the overall structure is hexagonal. Hexagonal and other structural designs allow for the flexible combination of multiple overall structures, integrating them into contactors of different shapes in series, parallel, or a combination of series and parallel connections, significantly improving application flexibility.

[0069] In some embodiments, multiple integral structures may be stacked and rotated in a staggered manner to mix airflow.

[0070] In some embodiments, the overall structure is manufactured by extrusion molding or 3D printing, and the gradient heat transfer layer is achieved by partitioned deposition of copper powder.

[0071] Compared with traditional technologies, the significant advantages of the embodiments of the present invention are reflected in the following aspects:

[0072] 1. Enhance the heat transfer (heating / cooling) effect within the overall carbon dioxide adsorption structure.

[0073] This advantage is more pronounced compared to conventional monolithic structures or packed beds that do not employ the materials and structural design of this invention. Adjusting the adsorbent within the monolithic structure is a necessary step to improve its performance during adsorption (cooling) and regeneration cycles (heating). This invention modifies the copper powder ratio in a specific manner to construct different conduction paths, forming stable heat transfer channels. Simultaneously, by performing layered deposition of materials in specific regions of the monolithic structure, primarily altering the copper ratio, higher heat transfer efficiency is achieved by utilizing the metallic lattice properties of copper. Furthermore, by performing specific layered deposition of materials in specific regions of a single block, primarily adjusting the copper ratio, higher heat transfer efficiency can also be achieved, thanks to the metallic lattice of copper and the overall design.

[0074] 2. Integrated heating element

[0075] Integrated heating elements can be mounted on the outer wall of the overall structure to serve as the heat source for the desorption process. The heating element surface is coated with an enamel layer to simplify the manufacturing process and recycling steps, and to facilitate disassembly. The heating element can be integrated into each outer layer and can be adjusted according to its position in the larger system and the condition of adjacent integral structures. It uses an S-shaped enamel-coated nickel-chromium wire placed inside the outer wall.

[0076] 3. Prevent delamination (surface peeling)

[0077] Compared to designs with embedded metal plates or heat sinks, this invention offers advantages such as avoiding these problems, providing a simpler solution, and requiring fewer manufacturing processes. During manufacturing, a heat transfer layer is formed by directly depositing metal particles in a specific shape, making the overall structure a heterogeneous composite material. Unlike internal metal plates or finned heat sinks, it is not subject to the effects of periodic heating and cooling. Simultaneously, the diameter, arrangement, and enamel treatment of the heating wires prevent point stress, achieving uniform expansion throughout the entire structure. This prevents cracking, peeling, and delamination with other carbon dioxide adsorption materials, ensuring long-term stability.

[0078] 4. Minimize voltage drop

[0079] Pressure drop refers to the resistance encountered by airflow as it passes through the adsorbent material, resulting in a decrease in air pressure from the inlet to the outlet. This invention employs a channeled, monolithic design with a low-pressure-drop region, while the pores within the material capture carbon dioxide. Multiple monolithic structures can be stacked sequentially or in series, and further air mixing between stages can be achieved through rotation or offset. The composite matrix can be fabricated into various shapes with channels of different sizes, not limited to hexagonal channels, but also including circular, triangular, and other organically generated shapes.

[0080] 5. Optimize the compound ratio to avoid a significant decrease in carbon dioxide adsorption capacity.

[0081] This goal stems from the space-consuming nature of heat sinks due to size limitations, and is achieved through the development of a specific product formulation referred to in this invention as a composite matrix. The composite matrix primarily consists of the following components: clinoptilolite as the main carbon dioxide adsorption layer, kaolin as the main structural and elastic layer, methyl cellulose (MC, in its basic form, or similar to carboxymethyl cellulose CMC or hydroxypropyl methyl cellulose HPMC) as the main binder layer, collectively forming the adsorption material; and a copper-deposited heat transfer layer, both of which together constitute the composite matrix. Further explanation of the adsorption material follows:

[0082] - Clinoptilolite: A naturally occurring zeolite with a specific pore size in its internal structure, which is advantageous for capturing and trapping carbon dioxide molecules without interfering with nitrogen or oxygen molecules, which are the main components of the air. This material can withstand the temperature rise required during regeneration (carbon dioxide release) and the manufacturing of the overall structure, and will not pose a health hazard when used after its decommissioning. It is also resistant to oxidation and degradation; its high silica-to-alumina ratio gives it better hydrophobicity.

[0083] - Kaolin: A naturally occurring clay that becomes plastic when water is added, and is used as a structural and elastic layer to bind the components together.

[0084] - Methylcellulose (including hydroxypropyl methylcellulose and carboxymethyl cellulose): a polymer derived from plant fibers, used as a binder and gelling agent in the production process for the manufacture of the overall structure and to ensure the uniform distribution of the components.

[0085] 6. Self-supporting capacity of the overall structure

[0086] This capability solves the problem of needing to construct additional structures to fix the powdered adsorbent, resulting in a sufficiently robust overall structure to withstand weight and airflow impact. This structure is not only self-supporting but can also support multiple other integral structures, possessing sufficient strength. This is primarily achieved by combining clinoptilolite, kaolin, and methylcellulose dispersions during the production process.

[0087] The following describes specific embodiments of the present invention.

[0088] Figure 1 and Figure 2 An embodiment of a hexagonal self-supporting monolithic structure is shown, with a side length of, for example, 5 cm. The structure is made of composite material and mainly comprises absorbent material 1 (unshaded area) and different copper deposition layers and areas (highlighted with different shading patterns).

[0089] In some embodiments, the raw materials of adsorbent material 1 comprise, by weight percentage, 70-85% clinoptilolite, 5-20% kaolinite, and 1-15% methylcellulose solution. The proportions of the raw material components of adsorbent material 1 may vary depending on the natural source or composition of the raw materials, but mainly include: clinoptilolite up to 85%, kaolinite up to 20% by dry weight, and methylcellulose aqueous solution or gel solution up to 15%, while also considering the proportion of water used to wet the dry matter—the specific proportion depends on the overall structure size and the particle size of clinoptilolite and kaolinite.

[0090] like Figures 1 to 4 As shown, the adsorbent material 1 constitutes the main part of the overall structure, providing most of the carbon dioxide adsorption capacity; the multi-channel structure 2 is a low-pressure-drop channel with a hexagonal cross-section, used for the circulation of ambient air and forced airflow. The gradient heat transfer layer includes four main copper deposition heat transfer layers / regions: the outer wall static region 6, the intermediate static region 3, the inner circumferential static region 4, and the dynamic heat transfer region 5. The dynamic heat transfer region 5 is further divided into three sub-regions: the outer terminal region 5a, the intermediate sub-region 5b, and the inner terminal region 5c, forming a transition zone. The copper deposition ratio of each static region is in the order of outer wall static region 6 < intermediate static region 3 < inner circumferential static region 4. Among them, the layer with the worst thermal conductivity (outer wall static region 6) has a copper content of less than 5%, while the layer with the best thermal conductivity (inner circumferential static region 4) can have a copper content as high as 20%. This ratio is set to ensure that the copper content of the heat transfer layer increases from the outer wall to the core of the overall structure, in order to meet the circumferential heating requirements of the material. In addition, the particle size of copper powder is much larger than that of zeolite pores / pore size. For example, the particle size of 800-mesh copper powder is about 18.75 micrometers, while the pores of zeolite are below the nanoscale. Therefore, even if the copper content in the inner static zone reaches 20%, the copper powder cannot block the pores of zeolite. Moreover, the size of gas molecules is only a few tenths of a nanometer (10,000 times smaller than a micrometer), which can normally enter the pores of zeolite and be captured by the high quadrupole moment of carbon dioxide and the strong electrostatic interaction between the cations in zeolite. The presence of copper powder will not reduce the carbon dioxide adsorption efficiency.

[0091] The dynamic heat transfer zone 5 consists of regions with a gradient in copper deposition. On its cross-section facing the core of the overall structure, the copper ratio satisfies the following sequence: outer terminal region 5a < inner terminal region 5c < intermediate sub-region 5b. This specific choice of ratio sequence stems from the fact that, due to the shape characteristics of the overall structure, the dynamic heat transfer zone 5 contracts towards the center of the structure, and the distance between each part becomes increasingly closer. Therefore, stronger heat capacity and heat transfer capability can be obtained without further increasing the copper deposition. The dynamic heat transfer zone 5 can efficiently and uniformly achieve heat transfer from the constant copper ratio heat transfer region (outer wall static region 6) at the boundary wall of the overall structure to the intermediate static region 3 and the inner peripheral static region 4; the intermediate static region 3 and the inner peripheral static region 4 can then transmit heat circumferentially. This is because heat can be efficiently transferred from low conductivity regions (low copper content regions) to high conductivity regions (high copper content regions). The copper content of the dynamic heat transfer layer increases along the core or center direction of the overall structure.

[0092] The integrated heating element 7, located within the boundary wall of the integral structure, is made of enamel-coated nickel-chromium heating wire (but the invention is not limited thereto) and is used to assist external heating during the regeneration process; simultaneously, its S-shaped meandering arrangement within the wall prevents cracking during the systemic heating-cooling cycle. By placing wires of different resistances, and by placing wires only on specific walls, the heating area within a system composed of multiple such and similar improved integral structures can be fine-tuned.

[0093] In practical applications, the copper powder used in the gradient heat transfer layer can be protected from oxidation. First, the clinoptilolite in the composite matrix has a selective sieving effect on oxygen molecules, preventing oxygen molecules from penetrating the zeolite pores and contacting the internal copper powder. Meanwhile, carbon dioxide molecules, due to their strong quadrupole moment and strong electrostatic interaction with the cations within the zeolite, can preferentially occupy adsorption sites, thus protecting the copper powder from oxidation. Second, the temperature during the regeneration process of the adsorbent material is always controlled below 200°C, and the system removes a large amount of ambient air (including oxygen) through vacuuming (applying a vacuum environment). Therefore, there are no oxidation conditions for the copper powder during the heating and regeneration process, effectively avoiding the problems of decreased thermal conductivity or structural breakage caused by the formation of copper oxide.

[0094] Figure 3 and Figure 4 The cross-section of the overall structure is shown, including only the copper deposition area (excluding the pure adsorption material area) to more clearly demonstrate the copper deposition design and visually show the transition area of ​​the dynamic heat transfer zone 5. The total amount of copper deposition in the static heat transfer zones (outer wall static zone 6, middle static zone 3, and inner peripheral static zone 4) generally increases towards the center. The copper content varies among the sub-regions of the dynamic heat transfer zone 5, with the middle sub-region 5b having the highest copper content and the outer terminal zone 5a having the lowest copper content. The ratio is: outer terminal zone 5a < inner terminal zone 5c < middle sub-region 5b. Figure 4The embedded heating wire and its terminals extending to the surface were also demonstrated. These terminals enable individual heating control and can also be connected in a daisy-chain manner. The thermal conductivity effectiveness of the improved gradient heat transfer layer (including the dynamic heat transfer zone) design was verified through simulation experiments. Heat transfer simulation was performed using Energy2D software developed by CharlesXie. The simulation results show (based on thermograms and data from multiple detection points at the same location) that the proposed gradient heat transfer layer design has a significantly higher heat transfer efficiency than the unimproved structure, effectively ensuring directional heat transfer.

[0095] Figure 5 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 1 . Figure 6 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 2 . Figure 7 Different views of the self-supporting overall structure according to embodiments of the present invention Figure 3 . Figure 8 This is a diagram showing the interval distribution of the static area on the outer wall according to another embodiment of the present invention (copper powder is deposited in part of the outer wall area). Figure 9 This is a different view according to another embodiment of the present invention.

[0096] In a preferred embodiment, the hexagonal monolithic self-supporting structure includes multiple channels that guide airflow through the adsorbent material layer with minimal pressure drop. The structure primarily consists of natural clinoptilolite (as the main carbon dioxide adsorption layer), natural kaolin (as a binder for structural stability), a methylcellulose mixture, and copper powder heat transfer layers in varying proportions. The proportions of each element and copper in the heat transfer layers gradually increase from the outer corners to the center of the monolithic structure to achieve uniform heating and rapid temperature changes. The hexagonal shape offers excellent structural characteristics, allowing multiple monolithic structures to be well-integrated into spaces of different shapes (e.g., circular cutouts in contactor chambers) with minimal unused space. This is essential because contactors with pressure / vacuum capabilities are typically cylindrical to ensure physical integrity.

[0097] The integrated heating element is primarily made of a nickel-chromium alloy (approximately 80:20 ratio), but is not limited to this material. Its surface is coated with an enamel layer to prevent potential damage or direct contact with copper particles. This alloy possesses sufficient flexibility to prevent damage to the overall structure when the material expands due to gradual heating and cooling. Firstly, within the temperature range involved in this invention, the thermal expansion of both the nickel-chromium alloy wire and the composite matrix is ​​insignificant, preventing severe cracking of the overall structure. Secondly, the electrode / contact area of ​​the integrated heating element acts as an expansion joint, accommodating the slight increase in wire length that may occur due to heating, further avoiding structural problems caused by differences in thermal expansion coefficients during thermal cycling, and ensuring heat transfer efficiency and structural integrity.

[0098] The composite matrix is ​​made by dispersing the material components, which makes the composite material more uniform in heat transfer within the material, thus preventing local overheating damage to the adsorbent material.

[0099] The multi-channel / porous structure of the composite matrix can take on a variety of alternative shapes and sizes, not limited to hexagonal channels, but also including circular, triangular and other arbitrarily organically generated shapes.

[0100] Specific manufacturing systems / methods for self-supporting integral structures:

[0101] Self-supporting monolithic structures can be manufactured in a highly automated and standardized manner using extrusion molding or 3D printing technology, forming micropores / channels inside the monolithic structure.

[0102] The manufacturing process of the overall structure is as follows: First, the adsorbent material is prepared; then, a copper deposition layer is added to specific areas and wires are embedded; next, the above components are placed in a mold or forming mechanism; after further drying and firing, a self-supporting overall structure with an integrated heating and / or cooling system is finally formed, made of clinoptilolite and natural binder. The precise deposition of copper powder in different areas can be achieved through a multi-layer deposition process with a particle spreader. The equipment used in this process has a mature application base; similar equipment has been used in industrial baking, such as powder spreading systems or application devices that can flexibly switch between base material streams and copper-containing material streams. Compared to pure materials in powder form, the heat-treated overall structure absorbs less water vapor from the air while still maintaining a similar or even higher carbon dioxide adsorption capacity.

[0103] More specifically: First, clinoptilolite is added to an aqueous solution of methylcellulose (including MC, CMC, or HPMC, etc.), and kaolin is added and thoroughly mixed to form a homogeneous substance A (the precursor of the adsorbent material, a mixed system containing clinoptilolite, kaolin, and methylcellulose binder); then, substance A is transferred to a mold or extrusion molding column, and according to the thermal conductivity design requirements of different areas of the overall structure (adapting to the copper ratio gradient of the gradient heat transfer layer), different proportions of copper powder are added (the amount of copper powder added varies with the region, corresponding to the copper content differences in the static area and dynamic heat transfer area of ​​the outer wall, etc.), forming a composite B. If an integrated heating system is required, enamel nickel-chromium wire or other heating wires can be embedded into the outer wall of the overall structure simultaneously (i.e., integrated heating element, this step is optional); the formed composite B is dried to remove free moisture, and then the structure is stabilized through a firing process, giving the overall structure mechanical strength and thermal stability. Regarding the thermal stability of the methylcellulose binder in this invention and the related process temperature control: First, the regeneration temperature of the system will not exceed 200°C. If moisture seeps into the system, most of the moisture will be removed at around 80°C, which can prevent the temperature from approaching or exceeding the decomposition temperature of the methylcellulose binder during the regeneration process. Second, the aforementioned firing / drying process can be carried out by extending the time at a lower temperature to achieve sufficient dehydration and structural stability. This invention does not require high-temperature firing to obtain the high strength of ceramic materials, and this low-temperature process also facilitates the later scrapping / retirement disposal of the overall structure. Third, the main function of the methylcellulose binder is to meet the needs of the manufacturing process, such as preparing slurry / gel materials suitable for extrusion molding and other processes. Even if the binder decomposes during long-term use, the main carbon dioxide capture layer in the system—clinocaloite—will not be affected and can still ensure the core carbon dioxide capture performance. The resulting self-supporting integral structure is composed of clinoptilolite and natural binders (kaolin + methylcellulose), and has integrated heating and cooling functions (achieving bidirectional heat transfer by relying on a gradient heat transfer layer). After heat treatment, it absorbs less water vapor from the air than the powdered pure material, while its carbon dioxide adsorption capacity is comparable to or even better than that of the pure material.

[0104] Figure 10 A high-density resin mold for hexagonal monolithic structure experiments is demonstrated in this embodiment of the invention. The mold is designed and manufactured using high-density and temperature-stable resin (capable of withstanding up to 110°C). Its thermal stability improves the curing (drying) speed of the monolithic structure before firing. The mold consists of three parts (containing four components), specifically including a core AF1 with hexagonal channels, a cover AF2, and two walls AF3; this design facilitates disassembly and cleaning of the mold after the monolithic structure has initially dried.

[0105] The important innovative designs of this invention include three aspects: First, a stable and self-supporting overall structure capable of capturing carbon dioxide is achieved through a specific combination of materials; second, the materials and internal structure are optimized, significantly enhancing the heating / cooling transfer capability; and third, by setting a gradient heat transfer layer in a precise mode (e.g., changing the proportion of copper powder added), specific heat transfer behavior is achieved within the structure, giving the material a highly modular characteristic that can be flexibly adjusted for different regions and systems.

[0106] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A self-supporting carbon dioxide capture monolith, characterized by, Comprise: A composite matrix, comprising: - an adsorbent material (1) containing clinoptilolite, kaolin and a methyl cellulose binder; - a gradient heat transfer layer formed by copper powder deposition in the adsorbent material, the proportion of copper content gradually increasing from the outer wall to the core of the overall structure, realizing directional heat transfer in the carbon dioxide adsorption-regeneration cycle; - a multi-channel structure (2) passing through the composite matrix to provide a low pressure drop gas flow path; The gradient heat transfer layer comprises: A static heat transfer zone, comprising: - an outer wall static zone (6) extending continuously or spaced along the circumference, located at the outermost boundary area of the overall structure, having a first constant copper proportion; - an intermediate static zone (3) extending continuously or spaced along the circumference, located inside the outer wall static zone (6), having a second constant copper proportion; - an inner circumferential static zone (4) extending continuously or spaced along the circumference, located inside the intermediate static zone (3), having a third constant copper proportion; Wherein, the first constant copper proportion < the second constant copper proportion < the third constant copper proportion; A dynamic heat transfer zone (5) extending radially from the outer wall static zone (6) to the center of the overall structure; comprising in turn along the radial direction: - an outer terminal zone (5a) adjacent to the outer wall static zone (6); - an intermediate sub-zone (5b) adjacent to the intermediate static zone (3) and the inner circumferential static zone (4); - an inner terminal zone (5c); Wherein, the copper proportion satisfies: the outer terminal zone (5a) < the inner terminal zone (5c) < the intermediate sub-zone (5b).

2. The self-supporting carbon dioxide capture monolithic structure of claim 1, wherein, taking the inner edge of the outer wall static zone (6) as the reference point to the center of the overall structure as the radial full range: - the intermediate static zone (3) is located at 1 / 3 of the radial full range; - the inner circumferential static zone (4) is located at 2 / 3 of the radial full range.

3. The self-supporting carbon dioxide capture monolithic structure of claim 1, wherein, the copper powder proportion of the gradient heat transfer layer is: the first constant copper proportion < 5%, the third constant copper proportion ≤ 20%.

4. The self-supporting carbon dioxide capture monolithic structure of claim 1, wherein, the raw materials of the composite matrix include, by weight: clinoptilolite 70-85 parts, kaolin 5-20 parts, methyl cellulose binder solution 1-15 parts.

5. The self-supporting carbon dioxide capture monolithic structure of claim 1, wherein, the cross-sectional shape of the multi-channel structure includes any one of hexagon, circle, triangle. Further comprising: An integrated heating element (7) provided in the outer wall of the overall structure and thermally coupled with the gradient heat transfer layer.

7. The self-supporting carbon dioxide capture monolithic structure of claim 6, wherein, the integrated heating element is a nichrome wire coated with an enamel layer, which is embedded in the outer wall of the overall structure in a serpentine shape, and the terminals extend to the outer wall surface to realize independent temperature control or daisy chain connection.

8. The self-supporting carbon dioxide capture monolithic structure of claim 1, wherein, 6. The self-supporting carbon dioxide capture monolith of claim 1, wherein, ​ ​ ​ ​ ​ The methylcellulose-based binder is selected from methylcellulose (MC), carboxymethylcellulose (CMC) or hydroxypropylmethylcellulose (HPMC).

9. The self-supporting carbon dioxide capture monolith of claim 1, wherein, The overall structure is hexagonal.

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