A biomass-based air water-harvesting material, and a preparation method and application thereof

Abstract

The application discloses a biomass-based air water collecting material and a preparation method and application thereof in air water collecting or water production after water collecting and evaporation. The preparation method comprises the following steps: (1) mixing clean biomass material powder with a phytic acid solution and performing a hydrothermal reaction at 120-200 DEG C, and after the reaction, washing and drying the solid product to obtain a black powder; and (2) immersing the black powder in a hygroscopic salt solution, and after the immersion, performing solid-liquid separation to obtain the biomass-based air water collecting material. The application can solve the problems of the existing water collecting material, such as non-renewable raw materials, high production cost, complex production process and the like, the water collecting material has high water absorption of the hygroscopic salt per unit mass, the hygroscopic salt consumption can be reduced, the raw material cost is reduced, the photo-thermal evaporation effect is good, and the water collecting material is beneficial to water reuse after water collecting and evaporation.

Description

Technical Field

[0001] This invention relates to the field of air water collection technology, specifically to a biomass-based air water collection material, its preparation method, and its application. Background Technology

[0002] The atmosphere is rich in water resources, with a water reserve six times the total amount of rivers worldwide. For regions lacking liquid water, air-based water harvesting is undoubtedly an excellent solution. Among them, adsorption-based solar-powered air-based water harvesting technology can utilize low-grade solar energy to drive regeneration. Its equipment structure is simple and its energy consumption is low.

[0003] Patent specification CN116874699A discloses a COFs material based on porphyrin and thiadiazole derivatives, its preparation method, and its applications, belonging to the field of covalent organic framework materials technology. The COFs material based on porphyrin and thiadiazole derivatives is synthesized by reacting tetraaldehyde phenylporphyrin with 1,3,4-thiadiazole-2,5-diamine. The COFs material based on porphyrin and thiadiazole derivatives simultaneously possesses excellent photothermal properties and water absorption capacity, making it suitable for atmospheric water collection and solving the problem of insufficient photothermal properties in traditional atmospheric water collection materials.

[0004] Currently, solar-powered air-to-water extraction technology based on adsorption faces challenges in its widespread application due to the complex manufacturing process of water collection materials, the non-renewable nature of raw materials, and the high production costs. The market urgently needs an adsorption material that can solve these problems.

[0005] Patent specification CN111496964A discloses a moisture-absorbing power-generating material based on ink and corn stalks and its preparation method. This patented technology uses corn stalks as a substrate, and the resulting material can collect water molecules from the air and obtain clean water through solar evaporation. Under one solar light intensity, its surface temperature rises to approximately 45°C after 1800 seconds of irradiation. Summary of the Invention

[0006] This invention provides a method for preparing biomass-based air water collection materials to solve the problems of non-renewable raw materials, high production costs, and complex manufacturing processes of existing water collection materials. The resulting water collection material has a high water absorption capacity per unit mass of hygroscopic salt, which can reduce the amount of hygroscopic salt used and lower the raw material cost. In addition, it has good photothermal evaporation effect, which is beneficial for the reuse of water produced by evaporation after water collection.

[0007] The specific technical solution is as follows:

[0008] A method for preparing a biomass-based air-collecting water material includes the following steps:

[0009] (1) The clean biomass material powder is mixed with phytic acid solution and subjected to hydrothermal reaction at 120-200℃. After the reaction is completed, the solid product is washed and dried to obtain black powder.

[0010] (2) The black powder is immersed in a hygroscopic salt solution. After immersion, the solid and liquid are separated, and the solid is dried to obtain the biomass-based air-collecting water material.

[0011] The preparation method of the biomass-based air-collecting water material of the present invention involves placing biomass material powder in a phytic acid solution for hydrothermal treatment, which can increase the specific surface area of ​​the material and achieve strong water collection performance under low hygroscopic salt load. At the same time, the material turns black, which enhances its photothermal performance and enables the rapid evaporation and release of absorbed water using solar energy.

[0012] In the preparation method of the biomass-based air-collecting water material, in step (1), the biomass material may include at least one of rice straw, corn straw, rapeseed straw, bamboo, balsa wood, pine wood, poplar wood, etc.

[0013] In the preparation method of the biomass-based air-collecting water material, in step (1), the mesh size of the biomass material powder can be 10 to 200 mesh.

[0014] In the preparation method of the biomass-based air-collecting water material, in step (1), the ratio of the amount of biomass material powder to the amount of phytic acid solution can be 1-5 g: 40 mL, and the mass concentration of the phytic acid solution can be 5%-40%.

[0015] In the preparation method of the biomass-based air-collecting water material, in step (1), the hydrothermal reaction time can be 4 to 8 hours.

[0016] In the preparation method of the biomass-based air-collecting water material, step (1) specifically includes washing the solid product repeatedly by soaking it in deionized water and ethanol until it is neutral.

[0017] In the preparation method of the biomass-based air-collecting water material, in step (1), the drying temperature can be 100-120℃.

[0018] In the preparation method of the biomass-based air-collecting water material, in step (2), the ratio of the amount of black powder to the amount of the hygroscopic salt solution can be 1g:15-25mL, and the concentration of the hygroscopic salt solution can be 0.1-5mol / L.

[0019] In the preparation method of the biomass-based air-collecting water material, in step (2), the hygroscopic salt may include at least one of lithium chloride, calcium chloride, magnesium chloride, etc.

[0020] In the preparation method of the biomass-based air-collecting water material, in step (2), the impregnation time can be 4 to 12 hours.

[0021] In the preparation method of the biomass-based air-collecting water material, in step (2), after impregnation, the solid-liquid separation can be completed, and the liquid can be taken directly or after adding hygroscopic salt for reuse.

[0022] In the preparation method of the biomass-based air-collecting water material, in step (2), the drying temperature can be 80-120℃.

[0023] The present invention also provides a method for preparing the biomass-based air-collecting material and the resulting biomass-based air-collecting material.

[0024] This invention also provides the application of the aforementioned biomass-based air-collecting material in air-collecting water or in water produced by evaporation after water collection. The evaporation water can be produced by photothermal evaporation.

[0025] Compared with the prior art, the beneficial effects of this invention are as follows:

[0026] This invention uses biomass materials as raw materials and performs simple hydrothermal modification with phytic acid to increase the porosity and enhance the photothermal properties of the materials. After phytic acid modification, hygroscopic salts are embedded to obtain a biomass-based water-collecting material. The low moisture absorption and high water absorption capacity of the hygroscopic salts, combined with the high porosity and high photothermal properties of the material, result in a water-collecting material with high water collection efficiency and high photothermal conversion performance. Furthermore, the raw materials used in this invention are renewable, low-cost, and the production process is simple with a high yield, making it suitable for large-scale production. Attached Figure Description

[0027] Figure 1 The graph shows the moisture absorption performance test results of the biomass-based air-collecting material at 25°C in Example 1 of this invention.

[0028] Figure 2 This is a graph showing the moisture absorption performance test results of the biomass-based air-collecting material at 25°C in Example 2 of the present invention;

[0029] Figure 3 This is a graph showing the moisture absorption performance test results of the biomass-based air-collecting material at 25°C in Example 3 of the present invention.

[0030] Figure 4 The graph shows the moisture absorption performance test results of the biomass-based air-collecting material of the present invention at 25°C, which is a comparative example of the present invention.

[0031] Figure 5 This is a comparison chart of the salt loading of biomass-based air-collecting materials in Examples 1, 2, 3, and the comparative examples of the present invention;

[0032] Figure 6The images show the surface temperature change curves and infrared thermal images of the biomass-based air-collecting water materials of Embodiment 1 and the comparative example of the present invention under sunlight. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] Unless otherwise specified, the operating methods in the following examples are generally performed under conventional conditions or as recommended by the manufacturer.

[0035] Example 1

[0036] 1) Preparation of biomass-based air-collecting water materials

[0037] At room temperature, rice straw is simply washed with water and dried. The washed and dried rice straw is then crushed using a crusher and sieved to obtain 60-80 mesh rice straw powder.

[0038] Subsequently, 3g of rice straw powder was placed in 40mL of 5% phytic acid solution at room temperature, stirred evenly, and then placed in a 160℃ oven for hydrothermal reaction for 6h. After naturally cooling to room temperature, the solid product was washed three times with deionized water and ethanol until neutral and dried at 100-120℃ to obtain a black powder.

[0039] Next, 1g of the black powder, after being washed by hydrothermal treatment, was immersed in 20mL of 2mol / L LiCl solution for 8 hours. After filtration, the resulting solid was dried in an oven at 80℃ to obtain a biomass-based air-collecting water material. The resulting liquid can be reused directly or after adding LiCl.

[0040] 2) Water collection performance test of biomass-based air-collecting materials

[0041] The water collection performance of the biomass-based air-collecting material of this embodiment was tested in a constant temperature and humidity chamber. (See attached text.) Figure 1 The results showed that, under conditions of 25℃ and relative humidity of 30%, 50%, 70%, and 90%, the adsorption capacity of the biomass-based air-collecting material in Example 1 after 8 hours was 0.36 g / L. -1 0.65gg -1 0.90gg -1 1.01gg -1 .

[0042] Example 2

[0043] 1) Preparation of biomass-based air-collecting water materials

[0044] At room temperature, the wheat straw is simply washed with water and dried. The washed and dried wheat straw is then crushed using a crusher to obtain 50-70 mesh wheat straw powder.

[0045] Subsequently, 3g of wheat straw powder was placed in 40mL of 10% phytic acid solution at room temperature, stirred evenly, and then placed in a 120℃ oven for hydrothermal reaction for 6h. After naturally cooling to room temperature, the solid product was washed three times with deionized water and ethanol until neutral and dried at 100-120℃ to obtain a black powder.

[0046] Next, 1g of the black powder, after being hydrothermally washed, was immersed in 20mL of 2mol / L LiCl solution for 8 hours, filtered, and the resulting solid was dried in an oven at 100℃ to obtain a biomass-based air-collecting water material. The resulting liquid can be reused directly or after adding LiCl.

[0047] 2) Water collection performance test of biomass-based air-collecting materials

[0048] The water collection performance of the biomass-based air-collecting material of this embodiment was tested in a constant temperature and humidity chamber. (See attached text.) Figure 2 The results showed that, under conditions of 25℃ and relative humidity of 30%, 50%, 70%, and 90%, the adsorption capacity of the biomass-based air-collecting material in Example 2 after 8 hours was 0.29 g g. -1 0.52gg -1 0.73gg -1 0.83gg -1 .

[0049] Example 3

[0050] 1) Preparation of biomass-based air-collecting water materials

[0051] At room temperature, the corn stalks are simply washed with water and dried. The washed and dried corn stalks are then crushed using a crusher to obtain corn stalk powder of 140-160 mesh.

[0052] Subsequently, 3g of corn stalk powder was placed in 40mL of 15% phytic acid solution at room temperature, stirred evenly, and then placed in an oven at 180℃ for hydrothermal reaction for 6h. After naturally cooling to room temperature, the solid product was washed three times with deionized water and ethanol until neutral and dried at 100-120℃ to obtain a black powder.

[0053] Next, 1g of the black powder, after being hydrothermally washed, was immersed in 20mL of 2mol / L LiCl solution for 8 hours, filtered, and the resulting solid was dried in an oven at 110℃ to obtain a biomass-based air-collecting water material. The resulting liquid can be reused directly or after adding LiCl.

[0054] 2) Water collection performance test of biomass-based air-collecting materials

[0055] The water collection performance of the biomass-based air-collecting material of this embodiment was tested in a constant temperature and humidity chamber. (See attached text.) Figure 3 The results showed that, under conditions of 25℃ and relative humidity of 30%, 50%, 70%, and 90%, the adsorption capacity of the biomass-based air-collecting material in Example 3 after 8 hours was 0.36 g g, respectively. -1 0.61gg -1 0.84gg -1 0.94gg -1 .

[0056] Comparative Example

[0057] 1) Preparation of biomass-based air-collecting water materials

[0058] At room temperature, rice straw is simply washed with water and dried. The washed and dried rice straw is then crushed using a crusher to obtain 60-80 mesh rice straw powder. The rice straw powder is washed three times with deionized water and ethanol until neutral and then dried at 100-120℃. Next, 1g of the washed product is immersed in 20mL of 2mol / L LiCl solution for 8h, filtered, and the resulting solid is dried in an oven at 80℃ to obtain a biomass-based air-collecting water material. The resulting liquid can be reused directly or after adding LiCl.

[0059] 2) Water collection performance test of biomass-based air-collecting materials

[0060] The water collection performance of the biomass-based air-collecting material in this comparative example was tested in a constant temperature and humidity chamber. (See attached text.) Figure 4 The results showed that, under conditions of 25℃ and relative humidity of 30%, 50%, 70%, and 90%, the comparative biomass-based air-collecting material could achieve an adsorption capacity of 0.32 g / L after 8 hours. -1 0.57gg -1 0.80gg -1 0.87gg -1 Under the same test conditions, all were inferior to Example 1.

[0061] Comparing the salt loading of each embodiment and the comparative example, it was found that the hygroscopic salt loading of the comparative example was 1.5 times that of Example 1. Figure 5 As shown, the biomass-based air-collecting material prepared by the method of the present invention can achieve better water collection performance while reducing the amount of hygroscopic salt and lowering the raw material cost.

[0062] For a further comparison of the surface temperature changes of the biomass-based air-collecting materials in Example 1 and the comparative example under sunlight, see [link to relevant documentation]. Figure 6 It was found that the heating rate of the biomass-based air-collecting material in Example 1 was higher than that of the comparative biomass-based air-collecting material, and the surface temperature of the biomass-based air-collecting material in Example 1 reached 64.9°C after 1800 seconds of irradiation, which was 13.9°C higher than that of the comparative biomass-based air-collecting material. These results demonstrate that the biomass-based air-collecting material prepared by the method of this invention possesses excellent photothermal properties.

[0063] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing a biomass-based air-collecting water material, characterized in that, Including the following steps: (1) A clean biomass material powder is mixed with a phytic acid solution and subjected to a hydrothermal reaction at 120~200℃. After the reaction is completed, the solid product is washed and dried to obtain a black powder. The ratio of the biomass material powder to the phytic acid solution is 1~5g:40mL, and the mass concentration of the phytic acid solution is 5%~40%. (2) The black powder is immersed in a hygroscopic salt solution. After immersion, the solid and liquid are separated, and the solid is dried to obtain the biomass-based air-collecting water material.

2. The preparation method according to claim 1, characterized in that, In step (1), the biomass material includes at least one of rice straw, corn straw, rapeseed straw, bamboo, balsa wood, pine wood, and poplar wood.

3. The preparation method according to claim 1, characterized in that, In step (1), the biomass material powder has a mesh size of 10 to 200 mesh.

4. The preparation method according to claim 1, characterized in that, In step (1), the hydrothermal reaction takes 4 to 8 hours.

5. The preparation method according to claim 1, characterized in that, In step (1): The washing process specifically includes: repeatedly soaking and washing the solid product with deionized water and ethanol until it is neutral; The drying temperature is 100~120℃.

6. The preparation method according to claim 1, characterized in that, In step (2): The ratio of the black powder to the hygroscopic salt solution is 1 g: 15~25 mL, and the concentration of the hygroscopic salt solution is 0.1~5 mol / L; The hygroscopic salt includes at least one of lithium chloride, calcium chloride, and magnesium chloride; The soaking time is 4 to 12 hours.

7. The preparation method according to claim 1, characterized in that, In step (2): After impregnation, the solid and liquid are separated, and the liquid can be reused directly or after adding hygroscopic salt. The drying temperature is 80~120℃.

8. The biomass-based air-collecting water material prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the biomass-based air-collecting material according to claim 8 in air-collecting water or water produced by evaporation after water collection.

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