TWI729963B - Composite adsorbent, method of preparing the same and use thereof - Google Patents

Abstract

A composite adsorbent, a method of preparing the same, and a use thereof are provided. The method includes the steps of: providing a silica raw material and an aluminum slag powder; adding the silica raw material and the aluminum slag powder into a sodium hydroxide solution and mixing, and then performing a microwave-assisted hydrothermal synthesis reaction to obtain a zeolite; and immersing the zeolite and titanium isopropoxide in an ethanol solution and mixing, then adding deionized water and stirring, and then performing the microwave-assisted hydrothermal synthesis reaction to obtain the composite adsorbent. A ratio of zeolite and titanium dioxide photocatalyst in the composite adsorbent is between 3:7 and 7:3 by weight. The composite adsorbent is used for absorbing an air pollutant, and the air pollutant includes carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol or ozone.

Description

Composite material adsorbent, its preparation method and its use

The present invention relates to an adsorbent, especially a composite material; the present invention also relates to a preparation method of an adsorbent, especially a preparation method of a composite material adsorbent; the present invention also relates to the use of an adsorbent, especially a composite The use of material adsorbents.

Research data shows that people spend about 89% and 6% of all activity time indoors and transportation, respectively, while the rest of the time is spent outdoors. Obviously, people spend most of their time indoors. There is a positive correlation between indoor air quality and human health, that is, long-term exposure to an environment with poor indoor air quality will endanger human health. The main factors affecting indoor air quality are indoor air pollutants, including carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol, total volatile organic compounds, bacteria, fungi, suspended particles with a particle size of less than or equal to ten microns, particulates (PM10), and particulates. Suspended particles (PM2.5) with a diameter less than or equal to 2.5 microns, etc. Therefore, the removal of indoor air pollutants will help avoid harm to human health.

The prior art mainly uses porous material adsorbents to adsorb indoor air pollutants including carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol, etc., to remove indoor air pollutants. However, when the adsorbent of the porous material reaches adsorption saturation, the adsorption effect of the adsorbent of the porous material will be reduced and the adsorption capacity will be lost.

In addition, in terms of industrial wastes such as waste glass and waste aluminum slag, waste glass is generally treated by dumping it into landfills or paving roads. However, the space of landfills is limited and the glass cannot be biodegraded, so it is not The recycled waste glass will cause a burden on the environment. In addition, if the waste aluminum slag is not properly treated and comes into contact with water, it is easy to release odorous ammonia gas, which is harmful to the environment. Therefore, based on the principle of environmental protection, if industrial wastes such as waste glass and aluminum slag are not recycled and reused, they will harm the environment and affect human health.

Therefore, industrial wastes such as waste glass and aluminum slag are recycled and reused, and composite adsorbents that can sustainably absorb indoor air pollutants including carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol, etc., are urgently needed in this field. Solve the problem.

In order to solve the above-mentioned problems in the prior art, the purpose of the present invention is to provide a method for preparing a composite adsorbent by using waste glass and waste aluminum slag to prepare silicon dioxide raw material and aluminum slag powder, respectively, and using a microwave-assisted hydrothermal synthesis method A zeolite is prepared, and then the zeolite and titanium isopropoxide are passed through a sol-gel method and a microwave-assisted hydrothermal synthesis method to prepare a composite material adsorbent.

Another object of the present invention is to provide a composite material adsorbent. Based on the total weight of the composite material adsorbent, the weight ratio of the zeolite and the titanium dioxide photocatalyst is between 3:7 and 7:3.

Another object of the present invention is to provide a composite material adsorbent for adsorbing air pollutants, wherein the adsorbed air pollutants include carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol or a combination thereof.

In order to achieve the above objective, the present invention provides a method for preparing a composite adsorbent, which includes the following steps: Provide silicon dioxide raw materials and aluminum slag powder; Add the silicon dioxide raw material and the aluminum slag powder with a molar ratio ranging from 1:1 to 5:1 into a 1 M to 5 M sodium hydroxide solution, and mix them uniformly to obtain a mixture; In a closed microwave digester, microwave-assisted hydrothermal synthesis reaction is performed at 90°C to 250°C for 3 minutes to 60 minutes, and then vacuum filtration is performed to obtain a third solid phase material; Drying to obtain a zeolite; and Dip the zeolite and titanium isopropoxide with a weight ratio ranging from 1:5 to 1:10 in an ethanol solution and stir evenly; then add deionized water and stir to obtain a white gelatinous substance; The gelatinous substance is dried to obtain a crystal; the crystal is placed in the closed microwave digester, and the microwave-assisted hydrothermal synthesis reaction is performed at 90°C to 250°C for 3 minutes to 60 minutes to obtain A composite adsorbent

In a specific embodiment, the step of providing the silicon dioxide raw material includes the following steps: adding a glass powder to a 2M to 4M HCl solution, stirring at 50°C to 70°C, and then performing vacuum filtration to obtain A first solid-phase material; and adding the first solid-phase material to a 3M to 5M H ₂ SO ₄ solution, stirring at 50°C to 70°C, vacuum filtration, and then rinsing with deionized water and drying , In order to obtain the silicon dioxide raw material.

In a specific embodiment, the step of providing the aluminum slag powder includes the following steps: adding a waste aluminum slag to a 0.0001M to 0.01MH ₂ SO ₄ solution, stirring at 50°C to 70°C, and vacuuming Filtering to obtain a second solid phase material; and washing the second solid phase material with deionized water and then drying to obtain the aluminum slag powder.

In a specific embodiment, the microwave-assisted hydrothermal synthesis reaction is performed at 100°C to 220°C for 10 minutes to 50 minutes.

In a specific embodiment, the microwave-assisted hydrothermal synthesis reaction is performed at 100°C to 180°C for 10 minutes to 30 minutes.

In a specific embodiment, the microwave-assisted hydrothermal synthesis reaction is performed at 100°C to 140°C for 10 minutes to 20 minutes.

In a specific embodiment, the microwave-assisted hydrothermal synthesis reaction is carried out at 100°C for 10 minutes.

The present invention also provides a composite material adsorbent prepared by a method for preparing a composite material adsorbent, comprising a zeolite and a titanium dioxide photocatalyst, wherein based on the total weight of the composite material adsorbent, the weight ratio of the zeolite and the titanium dioxide photocatalyst is intermediate Between 3:7 and 7:3.

In a specific embodiment, based on the total weight of the composite adsorbent, the weight ratio of the zeolite and the titanium dioxide photocatalyst is 4:6, 5:5, or 6:4.

The present invention also provides a composite material adsorbent for adsorbing air pollutants, wherein the adsorbed air pollutants include, but are not limited to, carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol or a combination thereof.

The preparation method of the composite adsorbent of the present invention uses waste glass and waste aluminum slag to prepare silicon dioxide raw materials and aluminum slag powder, respectively, so that the glass and waste aluminum slag can be recycled and reused, thereby avoiding environmental damage and achieving environmental protection The purpose. In addition, in the present invention, a zeolite is prepared from the silicon dioxide raw material and aluminum slag powder through the microwave-assisted hydrothermal synthesis method, and then the zeolite and titanium isopropoxide are prepared through the sol-gel method and the microwave-assisted hydrothermal synthesis method to obtain a zeolite. Composite material adsorbent. According to this, the microwave-assisted hydrothermal synthesis method of the present invention can effectively shorten the preparation process of composite material adsorbent and make the titanium dioxide photocatalyst evenly cover the surface of zeolite. The composite material adsorbent can make the titanium dioxide photocatalyst through light. The photocatalytic reaction is carried out so that the composite adsorbent can effectively and continuously adsorb air pollutants without the problem of adsorption saturation. Furthermore, the composite material adsorbent of the present invention is based on the total weight of the composite material adsorbent. The weight ratio of zeolite and titanium dioxide photocatalyst is between 3:7 and 7:3, and the composite material adsorbent can effectively adsorb Carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol, or combinations thereof.

The following is a specific embodiment to illustrate the implementation of the present invention. Those familiar with this technology can understand other advantages and effects of the present invention from the content disclosed in this specification. However, the exemplary embodiments disclosed in the present invention are for illustrative purposes only and should not be construed as limiting the scope of the present invention. In other words, the present invention can also be implemented or applied by other different specific embodiments, and various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the spirit of the present invention.

Unless otherwise stated herein, the singular forms "a" and "the" used in the specification and the appended patent application include plural entities. Unless otherwise stated herein, the term "or" used in the specification and the appended claims includes the meaning of "and/or".

Example 1" Preparation method of composite adsorbent

Referring to Figure 1, the steps of preparing the composite adsorbent include: S1: Use a crusher to crush and siev the broken glassware and beaker to obtain a glass powder, add 10 grams of glass powder to 30 ml of 3M HCl solution After stirring for 2 hours at 60°C and filtering through vacuum, a first solid phase material was obtained; after that, the first solid phase material was added to 30 ml of 4M H ₂ SO ₄ solution at 60°C Stir for 2 hours. After vacuum filtration, the first solid phase material is rinsed with deionized water and placed in an oven at 105°C for drying for 24 hours to obtain a white fine powdered silicon dioxide raw material; S2: 10 One gram of waste aluminum slag was added to 30 ml of 0.001MH ₂ SO ₄ solution, stirred at 60°C for 2 hours, and filtered through vacuum to obtain a second solid phase material; after rinsing the second solid phase material with deionized water , Placed in an oven at 105°C and dried for 24 hours to obtain an aluminum slag powder; S3: Add 18 grams of silicon dioxide raw material and 10 grams of aluminum slag powder to 30 ml of 3 M sodium hydroxide solution, at room temperature Stir for 24 hours to obtain a mixture; place the mixture in a closed microwave digester (model: CEM MARS 6, CEM Company, USA), carry out microwave-assisted hydrothermal synthesis reaction at 150°C for 15 minutes, and Vacuum filtration to obtain a third solid phase material, which is placed in an oven at 105°C for drying for 24 hours to obtain a zeolite; and, S4: through a sol-gel method, 0.5 g The zeolite and 0.5 g of titanium isopropoxide were immersed in 10 ml of ethanol solution and stirred evenly; then 10 ml of deionized water was added, and the mixture was stirred at room temperature for 24 hours to obtain a white gel-like substance; The crystalline substance was placed in an oven at 105°C for drying for 24 hours to obtain a crystal; the crystal was placed in a closed microwave digester and microwaved at 100°C for 10 minutes to obtain a photocatalyst with zeolite and titanium dioxide The composite adsorbent.

Example 2 Analyze the crystal phase and structure of zeolite

Use X-ray diffraction analyzer (XRD, model: Bruker D8) to perform qualitative analysis of the crystal phase of zeolite obtained in step S3. The result is shown in Figure 2. The zeolite has a diffraction angle of 2θ = 6 There are peaks at °, 10°, 12°, 15.5°, 18.5°, 20°, 23.5°, 26.5°, 30°, 30.5°, 31°, 32°, 33.5°, indicating that the zeolite system belongs to type X zeolite.

Use a scanning electron microscope (SEM, model: FEI Quanta 200) to observe the surface structure of the zeolite obtained in step S3 at a magnification of 4000 times. As shown in Figure 3, the result shows that the surface of the zeolite has many particles. Particles with similar diameters, and there are many pores between the particles, so that the specific surface area of the zeolite can be increased.

Example 3 Analyze the elemental composition of the composite adsorbent

Use energy dispersive spectrometer (EDS, model: FEI Quanta 200) to analyze the composition of the elements (Si), aluminum (Al) and titanium (Ti) of the composite adsorbent obtained in step S4, as shown in Figure 4 As shown, the results show that the atomic weight ratio of the elements silicon (Si) and aluminum (Al) contained in the composite adsorbent is about 1:1. Therefore, the composite adsorbent is a zeolite with a low silicon content. Zeolite with low silicon content has quite good cation exchange capacity, and has better electron affinity for polar molecules.

Example 4 Detecting the ability of composite adsorbents to adsorb air pollutants

The air pollutant detected in this embodiment uses formaldehyde as an example to detect the ability of zeolite, photocatalyst, and composite material adsorbent to adsorb formaldehyde. Put 0.5 g of zeolite, photocatalyst and composite material adsorbent (irradiated or unirradiated) in a fume cupboard containing 1.0 ppm initial concentration of formaldehyde and a relative humidity of 45% for 2 hours, and tested at different time points The concentration of formaldehyde in the fume cupboard. As shown in Figure 5, the results show that at the 20th minute, compared with zeolite, photocatalyst, and composite adsorbent without light irradiation, the composite adsorbent irradiated with light has a better ability to adsorb formaldehyde, and After the second hour of adsorption, the formaldehyde removal rates of zeolite, photocatalyst and composite adsorbent (irradiated with light) were 0%, 92.4% and 94.9%, respectively. Obviously, after the second hour of adsorption, the adsorption capacity of zeolite has reached its full capacity and cannot continue to adsorb formaldehyde. The composite adsorbent irradiated by light still has a good formaldehyde adsorption capacity.

Example 5 Detecting the ability of composite adsorbents with different ratios of zeolite and photocatalyst to adsorb air pollutants

The air pollutants tested in this embodiment are based on formaldehyde as an example. The ability of composite adsorbents with different ratios of zeolite and titanium dioxide photocatalyst to adsorb formaldehyde is tested. The total weight of the composite adsorbent is calculated based on the total weight of the composite adsorbent. The weight ratios of zeolite and titanium dioxide photocatalyst in the agent are 3:7, 4:6, 5:5, 6:4 and 7:3, respectively. Put 0.5 g of each composite adsorbent in a fume cabinet containing 1.0 ppm initial concentration of formaldehyde and a relative humidity of 45% for 2 hours, and irradiate light to detect the concentration of formaldehyde in the fume cabinet at different time points. As shown in Figure 6, the results show that after the second hour of adsorption, the formaldehyde removal rates of composite adsorbents with ratios of 3:7, 4:6, 5:5, 6:4 and 7:3 were 94.9. %, 90.5%, 86.0%, 83.1% and 78.7%. Obviously, after the second hour of adsorption, the composite adsorbent with a higher content of titanium dioxide photocatalyst has a better ability to adsorb formaldehyde.

Example 6 "Detecting the ability of different doses of composite adsorbents to adsorb air pollutants

The air pollutants detected in this embodiment are based on formaldehyde, and the ability of different doses of composite material adsorbents to adsorb formaldehyde is tested. The ratio of zeolite and titanium dioxide photocatalyst in the tested composite material adsorbent is 3:7. Put 0.1g, 0.2g, 0.3g, 0.4g and 0.5g of each composite adsorbent in a fume cupboard containing 1.0 ppm initial concentration of formaldehyde and a relative humidity of 45% for 2 hours, and irradiate them with light. Detect the formaldehyde concentration in the ventilation cabinet at the time point. As shown in Figure 7, the results show that after the second hour of adsorption, the formaldehyde removal rate of each composite adsorbent of 0.1 g to 0.5 g was 79.5%, 85.9%, 88.7%, 92.2% and 94.9%, respectively. Obviously, after the second hour of adsorption, the composite adsorbent with higher dosage has better capacity to adsorb formaldehyde.

Example 7 Detecting the influence of different relative temperatures in the chamber on the ability of composite adsorbents to adsorb air pollutants

The air pollutants detected in this embodiment are based on formaldehyde. The effect of different relative temperatures in the room on the ability of the composite adsorbent to adsorb air pollutants is tested, and the ratio of zeolite and titanium dioxide photocatalyst in the detected composite adsorbent It is 3:7. Put 0.5g of composite material adsorbent in a fume cupboard containing 1.0 ppm initial concentration of formaldehyde and relative humidity of 45%, 55%, 65%, 75% and 85% respectively for 2 hours. Detect the formaldehyde concentration in the ventilation cabinet at the time point. As shown in Figure 8, the results show that after the second hour of adsorption, the composite adsorbent has a formaldehyde removal rate of 94.9% for the exhaust cabinets with relative humidity of 45%, 55%, 65%, 75%, and 85%. , 95.2%, 95.5%, 95.8% and 96.2%. Obviously, after the second hour of adsorption, different relative temperatures in the room did not affect the ability of the composite adsorbent to adsorb formaldehyde.

Example 8 Detecting the influence of the initial concentration of different air pollutants in the room on the ability of the composite adsorbent to adsorb air pollutants

The air pollutants tested in this embodiment are based on formaldehyde. The initial concentration of different air pollutants in the room is tested for the effect of the composite adsorbent's ability to adsorb air pollutants. Zeolite in the tested composite adsorbent And the ratio of titanium dioxide photocatalyst is 3:7. Place 0.5 g of composite material adsorbent in a fume cupboard containing 1.0 ppm, 0.9 ppm, 0.8 ppm, 0.7 ppm and 0.6 ppm initial concentrations of formaldehyde and a relative humidity of 45% for 2 hours, and irradiate them at different times Point to detect the concentration of formaldehyde in the ventilation cabinet. As shown in Figure 9, the results show that after the second hour of adsorption, the formaldehyde removal rate of the composite adsorbent for the initial concentrations of 1.0 ppm and 0.6 ppm of formaldehyde were 94.9% and 89.8%, respectively. Obviously, after the second hour of adsorption, the composite adsorbent has a better ability to adsorb formaldehyde in a room containing a higher initial concentration of formaldehyde.

S1: Step 1 S2: Step 2 S3: Step 3 S4: Step 4

Figure 1 is a flow chart of the preparation method of the composite adsorbent of the present invention. Figure 2 is the 2θ peak of the diffraction angle of the crystal phase of the zeolite prepared in the method for preparing the composite adsorbent of the present invention. Figure 3 is a photograph of the surface structure of the zeolite prepared in the method for preparing the composite adsorbent of the present invention. Figure 4 is a diagram showing the elemental composition results of the composite adsorbent of the present invention. Figure 5 is a graph showing the result of adsorption of formaldehyde by the composite adsorbent, zeolite and photocatalyst of the present invention. Figure 6 is a graph showing the results of adsorption of formaldehyde by the composite material adsorbent of the present invention containing different weight ratios of zeolite and titanium dioxide photocatalyst. Figure 7 is a graph showing the results of adsorption of formaldehyde by the composite adsorbent of the present invention under different dosages. Figure 8 is a graph showing the results of adsorption of formaldehyde by the composite adsorbent of the present invention under different humidity. Figure 9 is a graph showing the results of adsorption of formaldehyde by the composite material adsorbent of the present invention under different initial concentrations of formaldehyde.

S1: Step 1

S2: Step 2

S3: Step 3

S4: Step 4

Claims (10)

A preparation method of composite material adsorbent, including the steps: Provide silicon dioxide raw materials and aluminum slag powder; Add the silicon dioxide raw material and the aluminum slag powder with a molar ratio ranging from 1:1 to 5:1 into a 1 M to 5 M sodium hydroxide solution, and mix them uniformly to obtain a mixture; In a closed microwave digester, microwave-assisted hydrothermal synthesis reaction is performed at 90°C to 250°C for 3 minutes to 60 minutes, and then vacuum filtration is performed to obtain a third solid phase material; Drying to obtain a zeolite; and Dip the zeolite and titanium isopropoxide with a weight ratio ranging from 1:5 to 1:10 in an ethanol solution and stir evenly; then add deionized water and stir to obtain a white gelatinous substance; The gelatinous substance is dried to obtain a crystal; the crystal is placed in the closed microwave digester, and the microwave-assisted hydrothermal synthesis reaction is performed at 90°C to 250°C for 3 minutes to 60 minutes to obtain A composite adsorbent. The preparation method according to claim 1, wherein the step of providing the silicon dioxide raw material includes the steps of: adding a glass powder to a 2M to 4M HCl solution, stirring at 50°C to 70°C, and vacuuming Filtering to obtain a first solid phase material; and adding the first solid phase material to a 3M to 5M H ₂ SO ₄ solution, stirring at 50°C to 70°C, vacuum filtration, and then deionized water After rinsing, drying is performed to obtain the silicon dioxide raw material. The preparation method according to claim 1, wherein the step of providing the aluminum slag powder includes the steps of: adding a waste aluminum slag to a 0.0001M to 0.01MH ₂ SO ₄ solution at 50°C to 70°C After stirring, vacuum filtration is performed to obtain a second solid phase material; and the second solid phase material is rinsed with deionized water and then dried to obtain the aluminum slag powder. The preparation method according to claim 1, wherein the microwave-assisted hydrothermal synthesis reaction is carried out at 100°C to 220°C for 10 minutes to 50 minutes. The preparation method according to claim 1, wherein the microwave-assisted hydrothermal synthesis reaction is carried out at 100°C to 180°C for 10 minutes to 30 minutes. The preparation method according to claim 1, wherein the microwave-assisted hydrothermal synthesis reaction is carried out at 100°C to 140°C for 10 minutes to 20 minutes. The preparation method according to claim 1, wherein the microwave-assisted hydrothermal synthesis reaction is carried out at 100°C for 10 minutes. A composite adsorbent prepared by the method for preparing a composite adsorbent according to any one of claims 1 to 7, comprising a zeolite and a titanium dioxide photocatalyst, wherein based on the total weight of the composite adsorbent, the The weight ratio of the zeolite and the titanium dioxide photocatalyst is between 3:7 and 7:3. The composite adsorbent according to claim 8, wherein based on the total weight of the composite adsorbent, the weight ratio of the zeolite and the titanium dioxide photocatalyst is 4:6, 5:5 or 6:4. A composite material adsorbent according to claim 8 for adsorbing air pollutants, wherein the adsorbed air pollutants include carbon dioxide, carbon monoxide, formaldehyde, acetaldehyde, phenol or a combination thereof.

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