Direct air carbon capture device

Abstract

The utility model discloses a direct air carbon capture device which comprises a light-transmitting flexible bag body, the flexible bag body comprises a substrate polymer layer on the outer layer and a spectrum regulation and control layer on the inner layer, and the flexible bag body is provided with a sealable air inlet and a sealable air outlet; a photo-thermal adsorbent composed of a porous carbon material and a CO2 adsorbent is arranged in the flexible bag body, and the spectrum regulation and control layer can reflect infrared light generated by the photo-thermal adsorbent; the air outlet is connected with a negative pressure device; the device can adsorb CO2, realizes regeneration and reutilization of the adsorbent by utilizing solar energy, and is light and easy to arrange.

Description

Technical Field

[0001] This utility model relates to carbon capture devices, and more particularly to a direct air carbon capture device. Background Technology

[0002] With the intensification of global climate change, carbon emission reduction and carbon capture have become key technologies for addressing the climate crisis. Traditional carbon capture technologies are mainly applied to industrial point sources (such as thermal power plants and steel mills), while direct air capture (DAC) technology, which can directly capture low concentrations of CO2 (approximately 0.04%) from ambient air and is not limited by emission sources, has become an important technological supplement for building a comprehensive carbon neutrality system. Currently, DAC technology faces challenges in practical applications, including high energy consumption and inflexible equipment.

[0003] High Energy Consumption: The high regeneration energy consumption of existing DAC technologies severely restricts their commercialization. Liquid absorption methods (such as potassium hydroxide / amine solution) require high-temperature regeneration (120-150℃), with steam accounting for over 70% of energy consumption; solid adsorption methods (such as MOFs and zeolite molecular sieves) typically consume 1800-2500 kJ / mol for regeneration. Carbon Engineering's technology in the US consumes 5.6 GJ / tCO2 for regeneration, and while Climeworks' "Orca" plant in Switzerland has achieved a capture capacity of 4000 tons / year, its energy consumption remains high, significantly weakening the net carbon emission reduction benefits of DACs. Solar energy, as a zero-carbon clean energy source, can be directly used for adsorbent regeneration, completely avoiding secondary carbon emissions and significantly improving the carbon yield of DACs, making it an ideal choice for solving the energy consumption problem.

[0004] Inflexible Device Design: Existing DAC devices are mostly large, fixed structures, bulky, and costly, making them difficult to adapt to distributed scenarios. Traditional DAC equipment (such as Carbon Engineering's million-ton-scale unit) has a large footprint, limiting deployment and making it inflexible in dealing with dispersed emission sources such as transportation and agriculture. Furthermore, existing devices typically separate adsorption and regeneration designs, requiring the transfer of adsorbent between the two systems, increasing operational complexity and energy consumption. Currently, the market lacks efficient DAC solutions that integrate adsorption and regeneration functions, are energy-saving, and have a flexible, easily deployable structure. Summary of the Invention

[0005] Purpose of the utility model: The purpose of this utility model is to provide a direct air carbon capture device that can adsorb CO2, regenerate and reuse the adsorbent using solar energy, and is lightweight and easy to install.

[0006] Technical solution: The direct air carbon capture device of this utility model includes a light-transmitting flexible bag, which includes an outer base polymer layer and an inner spectral control layer. The flexible bag is provided with a sealable air inlet and an air outlet. The flexible bag contains a photothermal adsorbent composed of porous carbon material and CO2 adsorbent. The spectral control layer can reflect the infrared light generated by the photothermal adsorbent. The air outlet is connected to a negative pressure device.

[0007] Based on the above technical solution, the entire device uses a flexible bag containing a photothermal adsorbent. It is soft, lightweight, and easy to arrange. The photothermal adsorbent contains a CO2 adsorbent that absorbs CO2 from the air. The flexible bag is translucent, allowing external light to enter and heat the photothermal adsorbent, separating the adsorbed CO2 and enabling its regeneration and reuse. The inner layer of the flexible bag, the spectral control layer, reflects the infrared light generated by the photothermal adsorbent, effectively preventing heat loss due to infrared radiation. This creates a "greenhouse effect" within the bag, more effectively utilizing solar energy for rapid and efficient heating inside. Furthermore, the photothermal adsorbent contains porous carbon material as its main material. Carbon has excellent heat absorption properties. When combined with a CO2 adsorbent, it forms a photothermal adsorbent, which effectively absorbs light inside the bag, achieving rapid local heating of the adsorbent and further improving the efficiency of CO2 separation and regeneration. Furthermore, a negative pressure device at the outlet guides air into the bag. After the CO2 adsorbent becomes saturated, a vacuum can be created inside the bag. In a vacuum environment, the temperature required for CO2 separation and regeneration is reduced, further lowering energy consumption. In summary, this device integrates CO2 adsorption materials and enables their regeneration. The entire process is energy-efficient, and the device is lightweight and easy to install.

[0008] Preferably, the substrate polymer layer has a light transmittance in the 400-2500 nm wavelength band. 85% polyimide, PDMS, fluorinated ethylene propylene copolymer, polyethylene or polytetrafluoroethylene material.

[0009] Light in the 400-2500nm wavelength range concentrates most of the energy of natural light, and the transmittance of the substrate polymer layer in this wavelength range is... 85% ensures that the light entering the bag has enough energy to heat the photothermal adsorbent.

[0010] Preferably, the spectral modulation layer is made of photonic crystal, polymer film, ultrathin metal film or nanocomposite material with a light transmittance greater than 85% in the 400-2500nm band and a light reflectance greater than 85% in the 3-20μm band.

[0011] The spectral control layer has a light transmittance of more than 85% in the 400-2500nm wavelength band to ensure that the light entering the bag has sufficient energy. The light reflectance in the 3-20μm wavelength band is also greater than 85% because the heat generated by the photothermal adsorbent is mainly infrared light in this wavelength band. This setting can effectively prevent the heat inside the bag from being lost due to infrared radiation.

[0012] Preferably, the porous carbon material has an absorption rate of >90% in the 400-2500nm wavelength band and a thermal conductivity greater than 50W / m·K.

[0013] The porous carbon material, arranged as described above, ensures sufficient absorption of light in the main wavelength bands inside the bag. Furthermore, its thermal conductivity meets the aforementioned conditions, ensuring that it can effectively transfer heat to the CO2 adsorbent, enabling CO2 separation and regeneration.

[0014] Preferably, the porous carbon material has a specific surface area greater than 800 m². 2 / g, porosity ranges from [50%, 80%], and pore size ranges from [2nm, 100nm].

[0015] The porous carbon material, as described above, has a sufficiently large surface area to facilitate uniform loading of the CO2 adsorbent and gas mass transfer.

[0016] Preferably, the air inlet is provided with a one-way valve that only allows gas to enter the flexible bag.

[0017] The air inlet is equipped with a one-way valve that only allows air to enter, which can prevent air from flowing out of the air inlet before the CO2 is absorbed by the photothermal adsorbent, thus ensuring the adsorption effect.

[0018] Beneficial Effects: Compared with the prior art, the beneficial effects of this utility model are as follows: By adopting a flexible and light-transmitting bag, the device is lightweight and easy to arrange, and allows light to enter the interior to regenerate the carbon absorbent material using only solar energy, thus saving energy; the reflective design of the inner layer of the flexible bag improves the utilization efficiency of solar energy, making it both energy-saving and efficient; the bag is equipped with a photothermal adsorbent composed of porous carbon material and CO2 adsorbent, enabling the device to combine the functions of CO2 absorption and regeneration; the porous carbon material achieves rapid local heating, improving separation efficiency; and the negative pressure device lowers the temperature required for separation, further improving the energy-saving effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the device. Detailed Implementation

[0020] As shown in the figure, the direct air carbon capture device of this utility model includes a light-transmitting flexible bag. The flexible bag includes an outer base polymer layer 1 and an inner spectral control layer 2. The flexible bag is provided with a sealable air inlet 3 and an air outlet 4. The flexible bag contains a photothermal adsorbent 5 composed of porous carbon material and CO2 adsorbent. The spectral control layer 2 can reflect the infrared light generated by the photothermal adsorbent 5. The air outlet 4 is connected to a negative pressure device.

[0021] The substrate polymer layer 1 has a light transmittance of 400-2500nm wavelength. It contains 85% polyimide, PDMS, fluorinated ethylene propylene copolymer, polyethylene or polytetrafluoroethylene. These materials are soft and heat-resistant, and the thickness can be set to 0.05-0.5 mm. The tensile strength is not less than 10 MPa, giving it good airtightness, folding performance and weather resistance.

[0022] The spectral modulation layer 2 employs materials such as photonic crystals (e.g., multi-level periodic film structures composed of TiO2 / MgF2 / SiO2, etc.) with light transmittance greater than 85% in the 400-2500nm wavelength band and light reflectance greater than 85% in the 3-20μm wavelength band, polymer films (e.g., polystyrene (PS), polymethyl methacrylate (PMMA) microspheres self-assembled into three-dimensional ordered structures or multilayer polymer interference films), ultrathin metal films (e.g., gold / silver films with a thickness <20 nm), metal-dielectric multilayer films (e.g., Ag / TiO2 stacked design broadband high-reflectivity films), metal / polymer composite films (e.g., gold / silver nanoparticles-polydimethylsiloxane (PDMS), thin film metal nanowire networks-polyethylene terephthalate (PET) films), and metal oxide films (e.g., indium tin oxide (ITO) or aluminum-doped zinc oxide (AZO) films). This design ensures efficient solar energy input while preventing internal heat loss through infrared radiation, forming a heat-insulating structure similar to a "greenhouse effect."

[0023] The spectral modulation layer 2 can be uniformly coated onto the inner surface of the substrate polymer layer 1 using various methods, including magnetron sputtering, spin coating, spraying, chemical vapor deposition, or dip coating. The specific method can be flexibly selected based on performance requirements, material type, production scale, and cost budget.

[0024] The porous carbon material is made of porous activated carbon, carbon aerogel, or mesoporous carbon; the CO2 adsorbent is made of activated carbon, amine-functionalized materials (such as polyethyleneimine, tetraethylenepentamine, etc.), metal-organic framework materials (such as MOFs, such as MOF-74, UiO-66), covalent organic framework materials, or zeolite molecular sieve materials, etc. The porous carbon material is configured to have a light absorption rate >90% in the 400-2500nm wavelength band and a thermal conductivity greater than 50 W / m·K, enabling efficient solar-driven regeneration; the specific surface area of ​​the porous carbon material is greater than 800 m². 2 / g, with a porosity range of [50%, 80%] and a pore size range of [2nm, 100nm], which facilitates uniform loading of CO2 adsorbent and gas mass transfer.

[0025] Photothermal adsorbent 5 aims to achieve the synergistic effect of photothermal regeneration and CO2 capture using porous carbon materials. The CO2 adsorbent is loaded into the pores of porous carbon through physical loading (such as dispersing porous carbon in CO2 adsorbent solution and then drying) or chemical bonding (such as surface functionalization grafting). The surface is selectively hydrophobically treated with hydrophobic materials (such as fluorinated polymers or siloxanes) to form moisture-resistant channels.

[0026] The photothermal adsorbent 5 can be placed in the flexible bag in any form, such as being fixed to the inner wall of the bag, or being filled in the bag, either partially or completely.

[0027] The air inlet 3 and air outlet 4 are located at opposite ends of the flexible bag. The air inlet 3 is equipped with a one-way valve that allows only gas to enter the flexible bag, and the air outlet 4 is equipped with a negative pressure device. When the CO2 adsorbent is not saturated, air can be introduced into the bag through the negative pressure device. When the CO2 adsorbent is saturated, the air inlet 3 can be closed, and the negative pressure device can be used to create a vacuum inside the bag. Under vacuum conditions, the temperature required for the CO2 adsorbent to separate CO2 can be reduced, and the negative pressure device can also draw the separated CO2 out of the bag. After the CO2 adsorbent has been regenerated, the air inlet 3 can be opened.

[0028] The negative pressure device can also be connected to a CO2 collection device to store the extracted CO2 during the separation and regeneration process for other uses, realizing the integration of CO2 capture and utilization and enhancing the practical value of the device.

[0029] A temperature sensor can also be installed on the photothermal adsorbent 5 and connected to an external controller 6. The controller 6 is connected to a negative pressure device to adjust the vacuum level or gas flow rate based on temperature feedback, thereby optimizing the adsorption-regeneration cycle efficiency.

[0030] All materials used in this device are existing materials, or the required materials can be prepared using existing processes and raw materials. This device has the following beneficial effects:

[0031] High-efficiency energy utilization: Solar energy is directly converted into thermal energy through spectral selective design, avoiding the traditional multi-stage conversion of light-electricity-heat, and improving energy utilization efficiency by more than 70%; Local photothermal effect concentrates thermal energy on the surface of the adsorbent, and the thermal energy utilization rate exceeds 80% (significantly improved compared to the 30% of traditional bulk heating); Vacuum-assisted desorption reduces the desorption temperature to 80-100℃ (traditionally 120-150℃), and the regeneration energy consumption is reduced to 1.2 GJ / tCO2.

[0032] Flexible, portable, and environmentally adaptable: The flexible polymer bag structure has excellent folding performance (can be folded to 1 / 5 of its original volume) and lightweight characteristics (less than 2.5 kg per square meter), making it easy to transport, install, and store. It is suitable for various application scenarios (such as field operations, building roofs, rural areas, and mobile devices), overcoming the limitations of traditional rigid devices that are large in size and inconvenient to deploy, and improving the practicality of direct air carbon capture technology.

[0033] Excellent cycling stability: Porous carbon materials enable localized photothermal heating of the photothermal adsorbent, reducing the overall thermal stress of the material and avoiding structural damage during cycling. Experiments have shown that the adsorption capacity retention rate exceeds 90% after 5000 cycles, far exceeding the upper limit of 3000 cycles for traditional materials.

[0034] Low cost advantage: Using low-cost porous carbon materials as the photothermal substrate, efficient capture can be achieved by loading CO2 adsorption materials or directly modifying adsorption functional groups, reducing material costs by more than 60% compared to traditional amine solution systems; the flexible substrate uses industrially available polymer materials, with mass production costs of less than $5 per square meter; the overall system cost is reduced by 50%, significantly improving economic efficiency.

[0035] High carbon yield and green benefits: Utilizing solar energy as an input energy source is clean and produces no secondary carbon emissions. Compared to traditional carbon capture technologies that rely on fossil fuels, carbon yield is significantly improved. Combining efficient capture with low-energy regeneration, the net carbon reduction per ton of CO2 captured is even higher, meeting the needs of green and low-carbon development.

[0036] To better illustrate this device, two embodiments are provided below for further explanation.

[0037] Implementation Case 1: Portable Field Carbon Capture Device

[0038] Application scenarios: Used for carbon capture experiments in field research or remote areas.

[0039] Device specifications:

[0040] Flexible bag dimensions: 1 m × 0.5 m × 0.2 m (approximately 0.02 m³ after folding) 3 ).

[0041] Base polymer layer: polyimide (thickness 0.1 mm, tensile strength 20 MPa).

[0042] Spectral modulation layer: Indium tin oxide (ITO) coating, applied to the inner surface of the substrate polymer layer.

[0043] Photothermal adsorbent: porous activated carbon supported with polyethyleneimine (PEI), 5 mm thick.

[0044] Work process:

[0045] Adsorption stage: Ambient air is introduced through the air inlet, and the air is driven to flow through the adsorbent layer by the fan connected to the air outlet.

[0046] Desorption stage: During the day, the adsorbent is heated to 90°C using sunlight. A portable vacuum pump is connected to the outlet (or a fan can be used instead of a vacuum pump, as long as it can create a vacuum inside the bag) to reduce the pressure to 10 kPa, thereby releasing CO2 from the CO2 adsorbent (PEI) in the photothermal adsorbent.

[0047] Data Records:

[0048] Photothermal adsorbent temperature rise curve: at 800 W / m 2 Under natural light, the temperature of the photothermal adsorbent rises from 25℃ to 90℃ in about 10 minutes, with a heating rate of about 8.6℃ / min.

[0049] CO2 concentration change curves at the inlet and outlet: CO2 concentration at the inlet was 400 ppm, the initial concentration at the outlet dropped to 50 ppm, and recovered to 350 ppm after adsorption saturation.

[0050] Cyclic stability results: The initial adsorbent adsorption capacity was 1 mol / kg, and the capacity retention rate was 90% (0.9 mol / kg) after 500 cycles.

[0051] Spectral data: The polyimide substrate has a transmittance of >85% in the 400-2500 nm range, and the spectral modulation layer has a reflectance of >85% in the mid-to-far infrared range (3-20 μm).

[0052] The daily CO2 capture is approximately 0.5 kg, and the device weighs approximately 2 kg.

[0053] This device is solar-powered and requires no external power source, making it suitable for areas without grid access.

[0054] Implementation Case 2: Small-scale carbon capture and utilization station in rural areas

[0055] Application scenario: Deployed in rural areas, it captures CO2 and uses it directly for greenhouse cultivation to increase crop yield.

[0056] Device specifications:

[0057] Flexible bag dimensions: 3 m × 2 m × 0.5 m, single-piece design.

[0058] Base polymer layer: polyethylene (thickness 0.15 mm, tensile strength 12 MPa).

[0059] Spectral modulation layer: a multilayer dielectric film structure coated on the inner surface of the substrate polymer layer.

[0060] Photothermal adsorbent: Carbon aerogel directly modified with amine functional groups, with a thickness of 8 mm.

[0061] Additional feature: The CO2 collection unit is connected to the greenhouse piping.

[0062] Work process:

[0063] Adsorption stage: Rural air is introduced through the air inlet, and the airflow is controlled by a one-way valve to capture CO2 in the environment.

[0064] Desorption stage: During the day, solar energy is used to heat the adsorbent to 85°C, the vacuum pressure is reduced to 20 kPa, and the released CO2 is directly transported to the greenhouse through pipelines for plant photosynthesis to promote crop growth.

[0065] Data Records:

[0066] Temperature rise curve of photothermal adsorbent: at 900 W / m 2 Under natural light, the temperature of the photothermal adsorbent rose from 25℃ to 85℃ in about 18 minutes, with a heating rate of about 3.3℃ / min.

[0067] CO2 concentration change curves at the inlet and outlet: CO2 concentration at the inlet was 400 ppm, the initial concentration at the outlet dropped to 60 ppm, and recovered to 380 ppm after adsorption saturation.

[0068] Cyclic stability results: The initial adsorption capacity was 1 mol / kg, and the capacity retention rate was 85% (0.85 mol / kg) after 5000 cycles.

[0069] Spectral data: The polyethylene substrate has a transmittance of >85% in the 400-2500 nm range, and the spectral modulation layer has a reflectance of >85% in the mid-far infrared (3-20 μm) range.

[0070] Approximately 5 kg of CO2 is captured daily and directly transported to the greenhouse, increasing the CO2 concentration inside the greenhouse to 800-1000 ppm (the suitable range for crop growth). Crop yields (such as tomatoes and cucumbers) increase by 15%-20%, and the cost of capturing each ton of CO2 is approximately US$50.

[0071] This device utilizes solar energy for green operation, and the captured CO2 is used on-site for greenhouse cultivation, which not only reduces carbon emissions but also improves agricultural economic benefits, resulting in high carbon returns.

Claims

1. A direct air carbon capture device, characterized by: The bag includes a light-transmitting flexible bag body, which includes an outer base polymer layer (1) and an inner spectral control layer (2). The flexible bag body is provided with a sealable air inlet (3) and an air outlet (4). The flexible bag body is provided with a photothermal adsorbent (5) composed of porous carbon material and CO2 adsorbent. The spectral control layer (2) can reflect the infrared light generated by the photothermal adsorbent (5). The air outlet (4) is connected to a negative pressure device.

2. The direct air carbon capture device of claim 1, wherein: The substrate polymer layer (1) is made of polyimide, PDMS, fluorinated ethylene propylene copolymer, polyethylene or polytetrafluoroethylene with a light transmittance of ≥85% in the 400-2500nm wavelength band.

3. The direct air carbon capture device of claim 1, wherein: The spectral modulation layer (2) is made of photonic crystal, polymer film, ultrathin metal film or nanocomposite material with a light transmittance greater than 85% for the 400-2500nm band and a light reflectance greater than 85% for the 3-20μm band.

4. The direct air carbon capture device of claim 1, wherein: The porous carbon material is porous activated carbon, carbon aerogel, or mesoporous carbon; the CO2 adsorbent is activated carbon, amine functionalized material, metal-organic framework material, covalent organic framework material, or zeolite molecular sieve material.

5. The direct air carbon capture device of claim 1, wherein: The porous carbon material has an absorption rate of >90% in the 400-2500nm wavelength band and a thermal conductivity greater than 50 W / m·K.

6. The direct air carbon capture device of claim 1, wherein: The porous carbon material has a specific surface area greater than 800 m 2 / g, a porosity ranging from [50%, 80%], and a pore size ranging from [2 nm, 100 nm].

7. The direct air carbon capture device of claim 1, wherein: The air inlet (3) is equipped with a one-way valve that only allows gas to enter the flexible bag.

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