Double-layer glass interval layer desiccant containing high-efficiency activated carbon and preparation process thereof

Abstract

The application relates to the technical field of desiccants, in particular to a double-layer glass interval desiccant containing high-efficiency activated carbon and a preparation process thereof. The desiccant is a granular composite desiccant with a particle size of 2-5 mm and is composed of the following components in percentage by mass: 45-55% modified coconut shell activated carbon; 25-35% silica gel; 15-20% calcium chloride; and 0.5-2% bentonite. The specific surface area of the modified coconut shell activated carbon is greater than or equal to 1500 m 2 / g, and the mesopore ratio is 30%-40%. The modified coconut shell activated carbon with high specific surface area and high mesopore ratio is used as a skeleton to efficiently adsorb organic volatile substances such as formaldehyde and benzene series; the composite hygroscopic system formed by the compounded calcium chloride and silica gel significantly improves the adsorption rate and total amount of water vapor; the bentonite is added as an anti-agglomerating agent, and the silica gel is used for shaping, so that the deliquescence of the calcium chloride and the pulverization of the activated carbon particles are effectively inhibited. The surface is coated with a silane coupling agent protective layer to ensure that the particles are stable for a long time and no dust is precipitated.

Description

Technical Field

[0001] This invention relates to the field of desiccant technology, specifically to a double-layer glass spacer desiccant containing highly efficient activated carbon and its preparation process. Background Technology

[0002] Double-glazed windows (insulating glass) are key components for achieving energy conservation and sound insulation in modern buildings. Their performance hinges on the sealed cavity formed by two panes of glass and a spacer, which must be kept consistently dry and clean to prevent condensation and fogging, and to maintain optical performance and thermal insulation coefficient. To keep the cavity dry, the industry standard practice is to fill the cavity of the aluminum spacer with a desiccant. For a long time, the industry has primarily used 3A molecular sieves or silica gel as desiccants, whose function is limited to the physical adsorption of water molecules.

[0003] Patent application CN202223107756.5 discloses a bagged desiccant with deodorizing function, comprising a bag body, activated carbon desiccant mixed particles, and a packaging component. The activated carbon desiccant mixed particles are disposed in the bag body, and the bag body has ventilation holes with connecting plastic rings welded inside the ventilation holes. The activated carbon desiccant mixed particles can absorb odor gases and moisture in the air. The connecting plastic rings between the front and back sides of the bag body can greatly increase the surface area for gas flow, thereby increasing the adsorption area and achieving a better adsorption effect.

[0004] This existing patented technology aims to absorb odors and moisture simultaneously, and increases the gas contact area through a special structure. While this solution achieves functional integration to some extent, its design is geared towards dehumidification and deodorization in open or semi-open spaces (such as wardrobes and storage boxes). Its technical concept and structure are completely unsuitable for the unique working environment of double-glazed windows. Furthermore, its replaceable design concept contradicts the core requirements of double-glazed windows: a one-time seal, absolute stability of internal materials, and zero maintenance.

[0005] Therefore, there is an urgent need in this field for a composite adsorbent material specifically adapted to a double-layer glass sealing spacer. It must not only have the ability to efficiently and synergistically adsorb water vapor and volatile organic compounds, but also meet the stringent requirements of maintaining extremely high structural stability, no dust precipitation, and morphology adapted to industrial filling processes under harsh environments with long-term sealing and drastic temperature changes. Summary of the Invention

[0006] In order to overcome the deficiencies in the prior art, the present invention aims to provide a double-layer glass spacer desiccant containing high-efficiency activated carbon and its preparation process, and to provide customized development of the entire chain from material formulation, particle morphology to surface properties to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides a double-layer glass spacer desiccant containing highly efficient activated carbon. This desiccant is a granular composite desiccant with a particle size of 2-5 mm, and is composed of the following components by mass percentage: Modified coconut shell activated carbon: 45-55%; Silicone: 25-35%; Calcium chloride: 15-20%; Bentonite: 0.5-2%; Among them, the specific surface area of ​​modified coconut shell activated carbon is ≥1500m². 2 / g, with a mesoporous content of 30%-40%; using coconut shell activated carbon as the base material, the pore size is expanded and the mesoporous content is optimized through microwave activation modification, thereby improving the synergistic adsorption capacity for water vapor, formaldehyde, benzene series compounds, etc.; the high moisture absorption capacity of calcium chloride and the shaping and leak-proof properties of silica gel are used to solve the problem of insufficient moisture absorption rate when activated carbon is used alone, while the added bentonite acts as an anti-agglomeration agent to inhibit the powdering of desiccant particles.

[0008] As a further improvement to this technical solution, modified coconut shell activated carbon is prepared by the following method: pulverize coconut shell activated carbon to 80-100 mesh, mix it with a 5%-8% potassium hydroxide solution at a solid-liquid ratio of 1:5, activate it with microwave power of 600-800W for 15-20 minutes, wash it until neutral, and dry it at 110-120℃ for 4-6 hours to obtain modified activated carbon with high specific surface area.

[0009] As a further improvement to this technical solution, the surface of the desiccant particles is coated with a silane coupling agent protective layer.

[0010] This invention provides a process for preparing a double-layer glass spacer desiccant containing highly efficient activated carbon, which includes the following steps: S1. Activated carbon modification: After pulverizing coconut shell activated carbon to 80-100 mesh, it is subjected to microwave alkali activation treatment, washed and dried to obtain modified coconut shell activated carbon. S2. Mixing of composite components: The modified coconut shell activated carbon obtained in step S1 is added to a mixing device in a certain proportion with silica gel, calcium chloride, and bentonite. The mass ratio is 50% modified activated carbon, 30% silica gel, 18% calcium chloride, and 2% bentonite. The mixture is added to a high-speed mixer and mixed at room temperature for 20-30 minutes to ensure uniform dispersion of each component. The mixture is then mixed at room temperature in a high-speed mixer at a speed of 800-1000 r / min for 20-30 minutes to obtain a mixture with high specific surface area modified activated carbon. S3. Low-temperature granulation: Deionized water is added to the mixture obtained in step S2 as a binder and granulation is carried out to obtain wet granules with a particle size of 2-5 mm; the amount of deionized water added is 5%-8% of the total mass of the mixture; the granulation temperature is 60-80℃. It adapts to the filling requirements of the spacer layer of double-glazed glass, realizing the integrated function of "moisture absorption and moisture prevention + adsorption of volatile organic compounds + long-term stability", thus extending the service life of double-glazed glass. S4. Surface coating treatment: The particles obtained in step S3 are contacted with a silane coupling agent solution to form a coating layer on their surface; the silane coupling agent solution is a 5% (w / w) silane coupling agent ethanol solution, and the spraying amount is 1%-2% of the particle mass; the coating treatment is carried out in a fluidized bed at 40-50℃ for 10-15 minutes to form a protective layer. S5. Drying and curing: The coated particles are dried and cooled to obtain the composite desiccant; drying is carried out at 90-100℃ for 2-3 hours to remove moisture and ethanol, and after cooling to room temperature, it is sealed and packaged to obtain the finished product.

[0011] The present invention also provides a double-layer hollow glass, filled with the above-mentioned double-layer glass spacer desiccant containing high-efficiency activated carbon, comprising two parallel and spaced glass plates and a spacer strip disposed between the peripheries of the two glass plates. The spacer strip is an aluminum spacer strip with an internal cavity, and the cavity is filled with a composite desiccant. The aluminum spacer strip is an aluminum strip bent into a frame shape, and its cavity is connected to the spacer cavity of the two glass plates through through holes opened along the length direction, so that the composite desiccant communicates with the cavity of the two glass plates for adsorption and drying treatment.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This double-layer glass spacer desiccant containing high-efficiency activated carbon and its preparation process, through the precise compounding of "high mesoporous modified coconut shell activated carbon" and "calcium chloride-silica gel composite moisture absorption system", achieves the synergistic adsorption and capacity distribution of water molecules and organic volatile molecules such as formaldehyde and benzene series, thereby achieving the integrated technical effect of simultaneously realizing deep drying and long-term adsorption of chemical pollutants in a closed hollow cavity.

[0013] 2. The desiccant containing high-efficiency activated carbon in the double-layer glass spacer and its preparation process, by introducing bentonite as an anti-agglomeration agent and combining it with the coating process of the surface silane coupling agent protective layer, achieves a dual enhancement of the internal structural stability and surface mechanical strength of the composite particles. This results in the technical effect of effectively inhibiting the deliquescence of calcium chloride and the pulverization of activated carbon under long-term moisture absorption and hot and cold cycling conditions, and preventing dust pollution on the inner surface of the glass.

[0014] 3. The double-layer glass spacer desiccant containing high-efficiency activated carbon and its preparation process, through the process design of "low-temperature granulation" and "precise particle size control", completes the transformation of composite powder materials into high-flowability, high-packing-density regular particles, thereby achieving the technical effect of perfectly adapting to the automated filling requirements of standard aluminum spacer cavities without producing filling dead corners.

[0015] 4. The double-layer glass spacer desiccant containing high-efficiency activated carbon and its preparation process modify coconut shell activated carbon through "microwave alkaline activation" to achieve directional control of its pore structure, thereby achieving the technical effect of significantly improving its adsorption kinetic efficiency for slightly larger organic volatile molecules while ensuring ultra-high specific surface area. Attached Figure Description

[0016] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, will select various possible shapes and proportions to implement the invention according to specific circumstances.

[0017] Figure 1 This is a flowchart illustrating the overall process for preparing the desiccant according to the present invention. Figure 2 This is a flowchart illustrating the process for preparing modified coconut shell activated carbon according to the present invention. Figure 3 This is a flowchart illustrating the process of compound mixing, low-temperature granulation, coating, and drying of the modified coconut shell activated carbon of the present invention. Detailed Implementation

[0018] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art will conceive of any possible variations of the invention, all of which should be considered within the scope of the invention. The terms "installation" and "connection" should be interpreted broadly, referring to direct connection as well as indirect connection through an intermediate medium.

[0019] The terms "central axis," "vertical," "horizontal," "front," "rear," "upper," "lower," "left," "right," "top," "bottom," "inner," and "outer" used herein to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of the invention, "a number" means two or more, unless otherwise explicitly specified.

[0020] Please see Figures 1-3 As shown, this invention provides a double-layer glass spacer desiccant containing highly efficient activated carbon. This desiccant is a granular composite desiccant with a particle size of 2-5 mm, and is composed of the following components by mass percentage: Modified coconut shell activated carbon: 45-55%; Silicone: 25-35%; Calcium chloride: 15-20%; Bentonite: 0.5-2%; Among them, the specific surface area of ​​modified coconut shell activated carbon is ≥1500m². 2 / g, with a mesoporous content of 30%-40%; using coconut shell activated carbon as the base material, the pore size is expanded and the mesoporous content is optimized through microwave activation modification, thereby improving the synergistic adsorption capacity for water vapor, formaldehyde, benzene series compounds, etc.; the high moisture absorption capacity of calcium chloride and the shaping and leak-proof properties of silica gel are used to solve the problem of insufficient moisture absorption rate when activated carbon is used alone, while the added bentonite acts as an anti-agglomeration agent to inhibit the powdering of desiccant particles.

[0021] As a further improvement to this technical solution, modified coconut shell activated carbon is prepared by the following method: pulverize coconut shell activated carbon to 80-100 mesh, mix it with a 5%-8% potassium hydroxide solution at a solid-liquid ratio of 1:5, activate it with microwave power of 600-800W for 15-20 minutes, wash it until neutral, and dry it at 110-120℃ for 4-6 hours to obtain modified activated carbon with high specific surface area.

[0022] As a further improvement to this technical solution, the surface of the desiccant particles is coated with a silane coupling agent protective layer.

[0023] This invention provides a process for preparing a double-layer glass spacer desiccant containing highly efficient activated carbon, which includes the following steps: S1. Activated carbon modification: After pulverizing coconut shell activated carbon to 80-100 mesh, it is subjected to microwave alkali activation treatment, washed and dried to obtain modified coconut shell activated carbon. S2. Mixing of composite components: The modified coconut shell activated carbon obtained in step S1 is added to a mixing device in a certain proportion with silica gel, calcium chloride, and bentonite. The mass ratio is 50% modified activated carbon, 30% silica gel, 18% calcium chloride, and 2% bentonite. The mixture is added to a high-speed mixer and mixed at room temperature for 20-30 minutes to ensure uniform dispersion of each component. The mixture is then mixed at room temperature in a high-speed mixer at a speed of 800-1000 r / min for 20-30 minutes to obtain a mixture with high specific surface area modified activated carbon. S3. Low-temperature granulation: Deionized water is added to the mixture obtained in step S2 as a binder and granulation is carried out to obtain wet granules with a particle size of 2-5 mm; the amount of deionized water added is 5%-8% of the total mass of the mixture; the granulation temperature is 60-80℃. It adapts to the filling requirements of the spacer layer of double-glazed glass, realizing the integrated function of "moisture absorption and moisture prevention + adsorption of volatile organic compounds + long-term stability", thus extending the service life of double-glazed glass. S4. Surface coating treatment: The particles obtained in step S3 are contacted with a silane coupling agent solution to form a coating layer on their surface; the silane coupling agent solution is a 5% (w / w) silane coupling agent ethanol solution, and the spraying amount is 1%-2% of the particle mass; the coating treatment is carried out in a fluidized bed at 40-50℃ for 10-15 minutes to form a protective layer. S5. Drying and curing: The coated particles are dried and cooled to obtain the composite desiccant; drying is carried out at 90-100℃ for 2-3 hours to remove moisture and ethanol, and after cooling to room temperature, it is sealed and packaged to obtain the finished product.

[0024] The present invention also provides a double-layer hollow glass, filled with the above-mentioned double-layer glass spacer desiccant containing high-efficiency activated carbon, comprising two parallel and spaced glass plates and a spacer strip disposed between the peripheries of the two glass plates. The spacer strip is an aluminum spacer strip with an internal cavity, and the cavity is filled with a composite desiccant. The aluminum spacer strip is an aluminum strip bent into a frame shape, and its cavity is connected to the spacer cavity of the two glass plates through through holes opened along the length direction, so that the composite desiccant communicates with the cavity of the two glass plates for adsorption and drying treatment. Example 1

[0025] Preparation process of desiccant containing high-efficiency activated carbon double-layer glass spacer: S1. Activated Carbon Modification: Take 1000g of coconut shell activated carbon and pulverize it to approximately 90 mesh. Add 5000g of a 6% potassium hydroxide solution and stir until homogeneous. Place in a microwave reactor and activate at 750W for 18 minutes. After activation, wash repeatedly with deionized water until the pH of the effluent is neutral. Filter out the washed activated carbon and dry it in an oven at 115℃ for 5 hours to obtain modified coconut shell activated carbon. The specific surface area was measured to be 1620m² / g, and the mesoporous content was approximately 35%.

[0026] S2. Mixing of composite components: Weigh 500g of the above modified activated carbon, 300g of silica gel (coarse-pore type), 180g of anhydrous calcium chloride powder, and 20g of bentonite. Put them into a high-speed mixer and mix at 900r / min for 25 minutes to obtain a uniformly mixed composite powder.

[0027] S3. Low-temperature granulation: Transfer the mixed powder to a granulator, and spray approximately 60g (6% of the total powder mass) of deionized water while stirring. Granulate at 70℃, and collect 2-5mm wet particles after sieving.

[0028] S4. Surface Coating Treatment: Place the wet particles in a fluidized bed and preheat to 45°C. Spray 15g of a 5% KH-550 silane coupling agent ethanol solution by atomization and treat under fluidized conditions for 12 minutes to uniformly coat the particle surface.

[0029] S5. Drying and Curing: Transfer the coated granules to an oven at 95°C and dry for 2.5 hours to completely remove moisture and residual ethanol. After cooling to room temperature, seal and package to obtain the finished composite desiccant A. Example 2

[0030] Preparation process of double-layer glass spacer desiccant containing high-efficiency activated carbon: The steps are the same as in Example 1, except that the mass of each component in step S2 is adjusted to: 450g modified activated carbon, 350g silica gel, 150g calcium chloride, and 50g bentonite. The finished composite desiccant B is obtained.

[0031] Comparative Example 1 Commercially available ordinary 4A molecular sieve desiccant.

[0032] Comparative Example 2 Unmodified ordinary coconut shell activated carbon (specific surface area 950 m² / g) was simply mixed with silica gel, calcium chloride and bentonite in the proportion of Example 1 and then granulated, but without surface coating treatment, to obtain comparative sample C.

[0033] Table 1 Key performance indicators of composite desiccants and traditional desiccants Static moisture absorption rate 25℃, RH 60%, 24h 38.2% 35.6% 22.1% 33.5% VOCs adsorption rate (formaldehyde) Initial concentration 2 mg / m³, sealed for 24 hours 96.5% 94.8% 15.3% 81.2% Anti-pulverization performance (fine powder ratio) Oscillation method, 30 minutes 0.3% 0.4% Not applicable (Note 1) 2.8% Application simulation test -10℃ to 50℃ thermal shock 100 times (initial humidity 80%, containing trace amounts of formaldehyde) The glass was clear and fog-free, with formaldehyde concentrations close to 0. Untested Slight water mist appeared, indicating formaldehyde residue. Untested Core physical property parameters Specific surface area and mesoporous content of modified activated carbon 1620m² / g, 35% 1620m² / g, 35% not applicable 950 m² / g (unmodified) Particle surface treatment With silane coupling agent coating layer Silane coupling agent Uncovered Uncovered Note 1: Commercially available 4A molecular sieves are high-strength synthetic zeolites, which are not easily pulverized, but their function is singular. In this comparison, the focus is on the functional differences rather than physical strength.

[0034] Note 2: The total mass of the components in Examples 1, 2 and Comparative Example 2 is 1000g, which ensures the fairness of the data comparison.

[0035] Performance testing Moisture absorption performance test: Refer to GB / T6287-2021 "Method for determination of static water adsorption of molecular sieves", and test the moisture absorption rate of the sample for 24 hours under the conditions of 25℃ and 60% relative humidity.

[0036] Results: The moisture absorption rate of sample A in Example 1 was 38.2%, that of sample B in Example 2 was 35.6%, that of molecular sieve in Comparative Example 1 was 22.1%, and that of sample C in Comparative Example 2 was 33.5%.

[0037] Volatile organic compounds (VOCs) adsorption test: Place 1g of sample in a 1L sealed container, inject a certain amount of formaldehyde gas (initial concentration 2mg / m³), measure the residual formaldehyde concentration in the container after 24 hours, and calculate the adsorption rate.

[0038] Results: The adsorption rate of sample A was 96.5%, the adsorption rate of sample B was 94.8%, the adsorption rate of molecular sieve in comparative example 1 was 15.3%, and the adsorption rate of sample C was 81.2%.

[0039] Anti-powdering test (oscillation method): Weigh 10g of sample and place it in a sieve cylinder containing 10 ceramic balls. After oscillating at a certain frequency for 30 minutes, weigh the mass of fine powder passing through the sieve.

[0040] Fine powder percentage (by mass) results: Sample A: 0.3%, Sample B: 0.4%, Sample C: 2.8%.

[0041] Application simulation test: Equal amounts of sample A and comparative example 1 molecular sieve were filled into two sealed test chambers simulating double-layered glass spacers. The initial humidity inside the chambers was 80%, and trace amounts of formaldehyde were present. Observation was performed after 100 cycles of thermal shock from -10℃ to 50℃.

[0042] Results: The glass inside the test chamber containing sample A was clear and fog-free, and the formaldehyde concentration was close to 0; the glass inside the test chamber containing molecular sieve of comparative example 1 showed slight water mist, and there was residual formaldehyde concentration.

[0043] The above tests show that the composite desiccant provided by this invention is significantly superior to traditional single desiccants and unmodified simple mixtures in terms of moisture absorption capacity, VOCs synergistic adsorption capacity and structural stability, and can fully meet the long-term, clean and dry requirements of modern high-performance double-glazed glass for the environment inside the spacer layer.

[0044] Results analysis: Highly efficient synergistic adsorption capacity: The products (A, B) in this invention embodiment far exceed the static moisture absorption rate of traditional molecular sieves (Comparative Example 1), proving that the "calcium chloride-silica gel" composite moisture absorption system significantly improves the water vapor adsorption capacity. Simultaneously, its formaldehyde adsorption rate is as high as 94% or more, while molecular sieves almost lack this function. This directly verifies the highly efficient adsorption of VOCs by activated carbon with a high mesoporous content, achieving integrated "moisture absorption + adsorption".

[0045] Excellent structural stability: The fine powder content of the product in this example is extremely low (≤0.4%), far lower than that of Comparative Example 2 (2.8%), which did not undergo surface coating treatment. This demonstrates the key role of the "bentonite anti-agglomeration agent" and "silane coupling agent surface coating" process in inhibiting calcium chloride deliquescence and activated carbon pulverization, and enhancing the mechanical strength of the particles, thus meeting the stringent requirement of zero dust release from insulating glass.

[0046] Comprehensive long-term performance verification: The results of application simulation tests are the most convincing. After simulating the cold and heat cycles of a real harsh environment, the system using the desiccant of this invention remained clean, dry, and free of contaminant residue; while the system using traditional molecular sieves exhibited fogging and formaldehyde residue problems. This comprehensively demonstrates the long-term reliability of the product of this invention in sealed, static, and rapidly changing temperature environments, solving the core problems pointed out in the background art.

[0047] Formulation Influence: Comparing Examples 1 and 2, when the proportion of activated carbon was slightly reduced and the proportion of silica gel was slightly increased (A: 50% activated carbon, 30% silica gel; B: 45% activated carbon, 35% silica gel), the moisture absorption rate (35.6%) and VOCs adsorption rate (94.8%) of sample B remained at extremely high levels, but were slightly lower than those of sample A with the optimal ratio (38.2%, 96.5%). This indicates that the component range defined in claim 1 (45-55% activated carbon, 25-35% silica gel) can effectively balance the two adsorption functions, with the central ratio (Example 1) showing the best performance.

[0048] Conclusion: This invention, through unique component design (modified activated carbon + composite hygroscopic salt + anti-powdering agent) and supporting processes (microwave modification, fluidized bed coating), successfully prepared a special desiccant with ultra-high moisture absorption capacity, efficient VOCs adsorption and extreme structural stability. Its comprehensive performance surpasses that of existing single-function desiccants and simple physical mixtures, and it is perfectly suited to the special application requirements of double-glazed (insulating glass) sealing spacers. Example 3

[0049] Fabrication of double-glazed units: Using conventional double-glazed production processes, curved aluminum spacers are used. The cavity of the spacers is filled with the composite desiccant A prepared in Example 1. Then, the following steps are performed in sequence: lamination, application of butyl sealant, and installation of external sealant (polysulfide sealant or silicone sealant) to produce a standard double-glazed component. The above is the prior art and will not be described in detail here.

[0050] It should be noted that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A preparation process for a double-layer glass spacer desiccant containing highly efficient activated carbon, characterized in that, Includes the following steps: S1. Activated carbon modification: After crushing coconut shell activated carbon, microwave alkaline activation treatment is performed, followed by washing and drying to obtain modified coconut shell activated carbon. S2. Mixing of composite components: The modified coconut shell activated carbon obtained in step S1 is added to a mixing device in proportion with silica gel, calcium chloride and bentonite, and mixed evenly at room temperature to obtain a mixture. S3. Low-temperature granulation: Deionized water is added to the mixture obtained in step S2 as a binder and granulation is carried out to obtain wet granules with a particle size of 2-5 mm. S4. Surface coating treatment: The particles obtained in step S3 are contacted with a silane coupling agent solution to form a coating layer on their surface; S5. Drying and curing: The coated particles are dried and cooled to obtain the composite desiccant; In step S2, the mixing is carried out in a high-speed mixer with a rotation speed of 800-1000 r / min for 20-30 minutes. This desiccant is a granular composite desiccant with a particle size of 2-5 mm, and is composed of the following components by mass percentage: Modified coconut shell activated carbon: 45-55%; Silicone: 25-35%; Calcium chloride: 15-20%; Bentonite: 0.5-2%; Among them, the specific surface area of ​​modified coconut shell activated carbon is ≥1500m². 2 / g, with mesoporous components accounting for 30%-40%; In step S4, the silane coupling agent solution is a 5% (w / w) silane coupling agent ethanol solution, and its spraying amount is 1%-2% of the particle mass; the coating treatment is carried out in a fluidized bed at 40-50℃ for 10-15 minutes.

2. The preparation process of the double-layer glass spacer desiccant containing high-efficiency activated carbon according to claim 1, characterized in that: In step S3, the amount of deionized water added is 5%-8% of the total mass of the mixture; the granulation temperature is 60-80℃.

3. The preparation process of the double-layer glass spacer desiccant containing high-efficiency activated carbon according to claim 2, characterized in that: In step S5, drying is carried out at 90-100℃ for 2-3 hours.

4. The preparation process of the double-layer glass spacer desiccant containing high-efficiency activated carbon according to claim 3, characterized in that, Modified coconut shell activated carbon is prepared by the following method: Coconut shell activated carbon is pulverized to 80-100 mesh, mixed with a 5%-8% potassium hydroxide solution at a solid-liquid mass ratio of 1:5, activated by microwave power of 600-800W for 15-20 minutes, washed until neutral, and dried at 110-120℃ for 4-6 hours; the surface of the desiccant particles is coated with a silane coupling agent protective layer.

5. A desiccant containing a double-layered glass spacer with highly efficient activated carbon, characterized in that: The desiccant is prepared by the preparation process described in any one of claims 1-4.

6. A double-glazed insulating glass unit, filled with a double-glazed spacer desiccant containing highly efficient activated carbon as described in claim 5, comprising two parallel and spaced-apart glass plates and a spacer strip disposed between the peripheries of the two glass plates, characterized in that: The spacer is an aluminum spacer with an internal cavity, and the cavity is filled with the composite desiccant.

7. The double-glazed insulated glass according to claim 6, characterized in that: The aluminum spacer is a bent aluminum strip, and its cavity is connected to the spacer cavity of the two glass plates through through holes opened along the length direction.

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