ZSM molecular sieve, method for synthesizing ZSM molecular sieve by using retired fan blade and application of ZSM molecular sieve

Abstract

The invention discloses a ZSM molecular sieve, a method for synthesizing the ZSM molecular sieve by using a decommissioned fan blade and application, and belongs to the technical field of solid waste recycling and high-valued.The decommissioned fan blade is subjected to pyrolysis and then subjected to primary calcination, and glass fibers are obtained; the preparation method comprises the following steps: grinding, crushing, mixing with alkali, carrying out secondary calcination, grinding, uniformly mixing with water, and carrying out solid-liquid separation to obtain a precursor solution containing silicon and aluminum elements; mixing with a template agent aqueous solution, and aging to obtain initial gel; and carrying out hydrothermal reaction, solid-liquid separation, drying, three times of calcination and grinding to obtain the ZSM type mesoporous molecular sieve. The glass fibers in the retired fan blades are used as silicon and aluminum sources, so that the dependence on high-cost raw materials in the traditional ZSM molecular sieve production process is reduced, and the production cost is remarkably reduced. The high-value utilization of the glass fiber in the retired fan blade is effectively realized, the glass fiber is converted into the ZSM molecular sieve with economic and industrial values, and the utilization rate of waste resources is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste resource utilization and high value creation, and specifically relates to a ZSM molecular sieve and a method and application of synthesizing the ZSM molecular sieve by using retired fan blades. Background Art

[0002] The use of structured organic compounds in the zeolite synthesis process can adjust the material porosity, increase the silicon content, direct the synthesis of specific structures, and even discover new zeolite topologies. In 1972, Mobil Oil Company obtained a patent for ZSM-5 by adding tetrapropylammonium hydroxide (TPAOH) in hydrothermal synthesis. This molecular sieve contains a large amount of silicon and has direct channels and sinusoidal channels with dimensions of 0.53×0.56nm. 2 and 0.51×0.55nm 2 , usually used as a catalyst and adsorbent, with excellent selectivity and activity. ZSM-11 molecular sieve belongs to the Pentasil molecular sieve family. It was first successfully synthesized by Kokotail GT in 1978. Its pore structure is a cross-shaped pore. It has been used in traditional chemical industry and some new application fields with its unique structure and performance and has good reaction effect. However, ZSM molecular sieves are generally synthesized by silicon precursors through template method. However, the template used to form the precursor solution has the disadvantages of high cost and high energy consumption. The dependence on the template during synthesis puts it at a disadvantage in cost reduction and environmental protection, which weakens its wide application and competitiveness in the market. Only by solving the cost and environmental protection problems of ZSM molecular sieve synthesis can its wider application in the industrial field be accelerated. Therefore, for many years, researchers have focused their research on finding cheap silicon and aluminum sources.

[0003] Wind turbine blades are the core components of wind turbines, and their shells are mainly composed of composite materials made of glass fiber and thermosetting resin. With the continuous increase in the scale of the wind power industry, more and more wind turbine blades will be retired one after another. In order to effectively utilize the resources in these retired blades, pyrolysis has gradually become the focus of attention for recycling glass fibers. However, due to the short size and reduced mechanical properties of recycled glass fibers, there is currently a lack of suitable utilization channels. Studies have found that the main components of recycled glass fibers are silicon oxide and aluminum oxide, and they mainly exist in an amorphous form, which is easy to extract and has the potential to be used as a cheap silicon and aluminum source to synthesize high-performance silicon-aluminum ZSM molecular sieves. This provides a new way to high-value utilization of glass fibers in retired wind turbine blades.

[0004] The synthesis of traditional ZSM molecular sieves relies on the template method of silicon precursors, but the template used is expensive and energy-intensive to produce, resulting in high synthesis costs. After the glass fibers in retired wind turbine blades are recycled by pyrolysis, they lack suitable utilization channels due to their short size and reduced mechanical properties. It is necessary to find an effective way to make high-value use of these recycled glass fibers to reduce resource waste and increase their economic value. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a ZSM molecular sieve and a method and application for synthesizing ZSM molecular sieve using retired fan blades, so as to solve the technical problems of high raw material cost of existing ZSM molecular sieves and insufficient high-value utilization of retired fan blades.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The invention discloses a method for synthesizing ZSM molecular sieve by using retired fan blades, comprising: pyrolyzing the retired fan blades, and then calcining them once to obtain glass fibers; grinding and crushing them, mixing them with alkali, calcining them twice, grinding them, mixing them evenly with water, and separating the solid from the liquid to obtain a precursor solution containing silicon and aluminum elements; mixing them with a template aqueous solution, and aging to obtain an initial gel; separating the solid from the liquid, drying, calcining them three times, and grinding them to obtain the ZSM molecular sieve.

[0007] Preferably, the pyrolysis temperature is 500-600° C.; the pyrolysis time is 20-40 min; and the pyrolysis atmosphere is nitrogen or argon.

[0008] Preferably, the temperature of the primary calcination is 500-600° C.; the time of the primary calcination is 20-40 min; and the atmosphere of the primary calcination is an oxygen-containing atmosphere or air.

[0009] Preferably, the alkali is at least one of sodium hydroxide, potassium hydroxide and sodium carbonate; and the mass ratio of the glass fiber to the alkali is (1-3):1.

[0010] Preferably, the temperature of the secondary calcination is 550-650° C.; and the time of the secondary calcination is 40-80 min.

[0011] Preferably, the aging time is 8-24 hours; the template aqueous solution is a mixture of tetrapropylammonium hydroxide or tetraethyl orthosilicate drops and tetrabutylammonium hydroxide.

[0012] Preferably, the temperature of the three calcinations is 500-700° C.; the time of the three calcinations is 3-9 hours; and the heating rate is 10° C. / min.

[0013] Preferably, the retired wind turbine blades contain 20-30wt% resin, 60-70wt% glass fiber and a small amount of structural adhesive; the glass fiber contains silicon dioxide, aluminum oxide and calcium oxide.

[0014] The invention also discloses a ZSM molecular sieve which is prepared by adopting the preparation method.

[0015] The invention also discloses the use of the ZSM molecular sieve prepared by the method of synthesizing the ZSM molecular sieve by using retired fan blades in preparing an adsorbent.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for synthesizing ZSM molecular sieves using retired fan blades. The method not only realizes the resource utilization and high-value utilization of retired fan blades by recycling the glass fibers in the retired fan blades, but also provides a cheap and environmentally friendly source of raw materials for the production of molecular sieve materials. By using the glass fibers in retired fan blades as silicon and aluminum sources, the dependence on high-cost raw materials in the traditional ZSM molecular sieve production process is reduced, thereby significantly reducing production costs. The high-value utilization of glass fibers in retired fan blades is effectively realized, and they are converted into ZSM molecular sieves with economic and industrial value, thereby improving the utilization rate of waste resources. By recycling and reusing materials in retired fan blades, the present invention reduces the burden of waste blades on the environment and supports the circular economy and sustainable development goals.

[0017] The present invention also discloses a ZSM molecular sieve obtained by the above-mentioned preparation method, which realizes high-value utilization of resources and significantly reduces production costs by recycling glass fibers in retired fan blades. The prepared ZSM molecular sieve has uniform particle size, typical MFI or MEL type topological structure, and coexistence of micropores and mesopores, which give it broad application prospects in the fields of adsorption and catalysis. Compared with traditional methods, the present invention not only provides a cheap and environmentally friendly source of raw materials for the production of molecular sieve materials, but also effectively improves the utilization rate of waste resources, supporting the circular economy and sustainable development goals.

[0018] The present invention also discloses the use of the ZSM molecular sieve prepared by the above-mentioned method of synthesizing ZSM molecular sieve using retired fan blades in the preparation of adsorbents; the prepared ZSM molecular sieve exhibits significant advantages. Its microporous and mesoporous structure enables the molecular sieve to have excellent adsorption performance and selectivity, and can efficiently adsorb and separate molecules of different sizes and properties. In addition, due to the environmental protection of its raw material source and the reduction of production costs, this adsorbent has higher economy and practicality in the fields of environmental protection, chemical industry, energy, etc. Therefore, the ZSM molecular sieve prepared by the present invention has broad application prospects in the preparation of efficient and environmentally friendly adsorbents, and provides strong support for the realization of green and sustainable adsorption and separation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the wide-angle XRD diffraction pattern of the ZSM molecular sieve synthesized in Example 1 of the present invention.

[0020] Figure 2 This is a transmission electron microscopy TEM image of the ZSM molecular sieve synthesized in Example 1 of the present invention.

[0021] Figure 3 The nitrogen adsorption-desorption isotherm curve and pore size distribution diagram of the ZSM molecular sieve synthesized in Example 1 of the present invention.

[0022] Figure 4 This is the wide-angle XRD diffraction pattern of the ZSM molecular sieve synthesized in Example 2 of the present invention.

[0023] Figure 5 This is a transmission electron microscopy (SEM) image of the ZSM molecular sieve synthesized in Example 2 of the present invention.

[0024] Figure 6 The nitrogen adsorption-desorption isotherm curve and pore size distribution diagram of the ZSM molecular sieve synthesized in Example 2 of the present invention. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings: The present invention provides a method for synthesizing ZSM molecular sieve by using retired fan blades, the method comprising the following steps: (1) First, the retired fan blades are pyrolyzed at a temperature range of 500-600°C in an inert atmosphere (nitrogen or argon) for 20-40 minutes to obtain glass fibers coated with residual carbon; (2) calcining the glass fiber coated with carbon residue obtained in step (1) in an oxygen-containing atmosphere (which may be air) at a temperature range of 500-600° C. for 20-40 minutes to completely remove the carbon residue on the glass fiber to obtain pure glass fiber; (3) grinding the obtained glass fiber, mixing it with alkali (one or more of sodium hydroxide, potassium hydroxide and sodium carbonate) in a mass ratio of (1-3):1, and calcining it at 550-650°C for 40-80 minutes; (4) subjecting the mixture obtained in step (3) to solid-liquid separation to obtain a precursor solution containing silicon and aluminum elements (the calcined product is ground into powder and then mixed with water, and then magnetically stirred and filtered to obtain a precursor solution rich in silicon and aluminum elements), and the prepared template aqueous solution is stirred and mixed with the precursor solution; (5) The initial gel obtained after aging the mixture obtained in step (4) for 8-24 hours is transferred to a high-pressure autoclave with a polytetrafluoroethylene reactor and subjected to a crystallization process. After solid-liquid separation, the solid product obtained after solid-liquid separation is dried and then calcined at 500-700° C. for 3-9 hours.

[0028] The retired wind turbine blades of the present invention contain components such as 20-30wt% resin, 60-70wt% glass fiber and a small amount of structural adhesive, wherein the glass fiber contains components such as silicon dioxide, aluminum oxide and calcium oxide.

[0029] After pyrolysis in step (1), the surface of the glass fiber will be covered with black carbon residue, so it is necessary to carry out calcination and oxidation to remove the carbon residue and obtain pure glass fiber (the surface color can be observed to turn white).

[0030] Step (3) extracts silicon and aluminum from the glass fiber by alkali melting to obtain a precursor solution rich in silicon and aluminum.

[0031] The template aqueous solution in step (4) is a mixture of tetrapropylammonium hydroxide or tetraethyl orthosilicate drops and tetrabutylammonium hydroxide.

[0032] Step (5) The mixed solution is allowed to stand for aging, and then the solution is subjected to a crystallization process. The solid product obtained by solid-liquid separation is placed in an oven for drying, and then placed in a muffle furnace and heated to a calcination temperature at a heating rate of 10°C / min and maintained for a period of time to remove the template, and the calcined product is ground into powder to obtain a ZSM molecular sieve.

[0033] The present invention also discloses a ZSM molecular sieve obtained by the above-mentioned preparation method. By recycling the glass fiber in the retired fan blades as a raw material, the present invention not only solves the problem of processing the discarded fan blades, but also converts them into ZSM molecular sieve materials with high added value. This conversion not only improves the utilization rate of waste resources, but also promotes the recycling of resources, which is in line with the concept of sustainable development. The production of traditional ZSM molecular sieves often relies on high-cost raw materials, such as pure silicon sources and aluminum sources. The present invention uses the glass fiber in the retired fan blades as silicon and aluminum sources, which significantly reduces the production cost and makes the production of ZSM molecular sieves more economical and feasible. By recycling and reusing the materials in the retired fan blades, the present invention reduces the pollution and burden of the discarded blades on the environment. This environmentally friendly preparation method helps to reduce resource consumption and waste emissions, and supports the goals of circular economy and green development. The ZSM molecular sieve prepared by the present invention has uniform particle size, regular morphology, and microporous and mesoporous structures. These characteristics make the ZSM molecular sieve have excellent performance in the fields of adsorption and catalysis.

[0034] The present invention also discloses the application of the ZSM molecular sieve prepared by the method of synthesizing ZSM molecular sieve using retired fan blades in the preparation of adsorbents; since the ZSM molecular sieve has microporous and mesoporous structures, it has a large specific surface area and a large pore volume, and therefore has a strong adsorption capacity. This adsorbent can efficiently adsorb and separate small molecules in gases and liquids, such as carbon dioxide, nitrogen, methane, etc., and has broad application prospects in the fields of environmental protection, chemical industry, energy, etc. The pore size and shape of the ZSM molecular sieve have certain selectivity, and its pore size can be adjusted as needed to achieve selective adsorption of specific molecules. This characteristic gives the ZSM molecular sieve a unique advantage in the separation and purification process. The prepared ZSM molecular sieve has good thermal stability and chemical stability, and can maintain the stability of its structure and performance in a wide temperature range and chemical environment. This stability enables the ZSM molecular sieve to maintain efficient adsorption performance under harsh working conditions. The ZSM molecular sieve can restore its adsorption performance through a simple regeneration treatment, such as removing substances adsorbed on the molecular sieve by heating, purging or chemical treatment. This regenerability gives ZSM molecular sieves a longer life and lower maintenance costs during use.

[0035] Example 1 A method for synthesizing ZSM molecular sieve using retired fan blades comprises the following steps: (1) Cut the retired fan blades into pieces and place them in a tubular furnace for pyrolysis at 550 °C for 30 min in a nitrogen atmosphere; (2) then calcining the glass fiber obtained in step (1) at 550° C. in an air atmosphere for 30 minutes to remove residual carbon, thereby obtaining pure glass fiber; (3) Grind the pure glass fiber, mix the glass fiber and sodium hydroxide in a mass ratio of 2:1, and calcine at 600°C for 1h; (4) The calcined product was ground into powder and mixed with water. After magnetic stirring for 6 hours, the solid-liquid separation was performed by suction filtration to obtain a precursor solution rich in silicon and aluminum elements. A template aqueous solution (tetrapropylammonium hydroxide was used as a template) was prepared and magnetic stirring was performed for 2 hours to completely dissolve it. The precursor solution was slowly dripped into the template aqueous solution, and appropriate amounts of tetraethyl silicate and sodium aluminate were added. The mixture was stirred for 12 hours to obtain an initial gel (Si:Al:TPAOH:H2O =13:1:3.4:575). The functions of tetraethyl silicate include: regulating the sol-gel process; the silicate sol generated by the hydrolysis of tetraethyl silicate can affect the properties of the gel, and thus affect the pore structure and specific surface area of ​​the molecular sieve. Its hydrolysis rate determines the gel forming process, which in turn affects the crystallinity and structure of the final molecular sieve. Control the density and stability of the structure; the addition of tetraethyl silicate helps to improve the crystallinity of the molecular sieve, making its pore structure more orderly, while improving the thermal stability and chemical stability of the material.

[0036] The functions of sodium aluminate include: regulating the pH value of the synthesis system; the hydroxide ions (OH⁻) in the sodium aluminate solution will affect the pH value of the solution, thereby affecting the formation of gel and the crystallization of the molecular sieve. Changes in pH value can affect the reaction rate of Al³⁺ and SiO2 during the synthesis process, as well as the structure of the final molecular sieve. Enhance structural stability; the reaction of the aluminum source in sodium aluminate and other reactants also helps to enhance the structural stability of the molecular sieve, especially improving the hydrolysis resistance and thermal stability during the catalytic process.

[0037] (5) The obtained initial gel was placed in a polytetrafluoroethylene-lined hydrothermal reactor and crystallized in an oven at 180°C for 72 hours. After the reaction, the solution in the reactor was filtered and washed, and the solid product was placed in an oven at 105°C for 12 hours to fully remove moisture. It was then placed in a muffle furnace and heated to 550°C at a heating rate of 10°C / min and maintained for 4 hours to remove the template and then ground into powder.

[0038] Figure 1 The wide-angle XRD diffraction pattern of the ZSM molecular sieve synthesized in Example 1 of the present invention is shown in FIG. Figure 1 It can be seen that the XRD spectrum of ZSM-5 shows that there are reflection peaks at 2θ: 7.9°, 8.7°, 22.8°, 23.5°, and 24.4° where characteristic diffraction peaks appear, indicating that they form an MFI structure, which is also one of the typical characteristics of ZSM-5 molecular sieves.

[0039] Figure 2 TEM image of the ZSM molecular sieve synthesized in Example 1 of the present invention. Figure 2 It can be seen from the transmission electron microscopy (SEM) image that the synthesized ZSM-5 molecular sieve particles are uniform in size, the molecular sieve has an elongated shape, and the particle size is about 35-40 μm.

[0040] Figure 3 The nitrogen adsorption-desorption isotherm and pore size distribution diagram of the ZSM molecular sieve synthesized in Example 1 of the present invention are shown in FIG. Figure 3 It can be seen that the isotherm belongs to a typical type I curve (Langmuir isotherm) with H4 loop hysteresis, indicating that the sample has microporous characteristics.

[0041] from Figure 1-Figure 3 It can be seen that in Example 1, a ZSM-5 type molecular sieve was prepared.

[0042] Example 2 A method for synthesizing ZSM molecular sieve using retired fan blades comprises the following steps: (1) Cut the retired fan blades into pieces and place them in a tubular furnace for pyrolysis at 550 °C for 30 min in a nitrogen atmosphere; (2) then calcining the glass fiber obtained in step (1) at 550° C. in an air atmosphere for 30 minutes to remove residual carbon, thereby obtaining pure glass fiber; (3) Grind the pure glass fiber, mix the glass fiber and sodium hydroxide in a mass ratio of 2:1, and calcine at 600°C for 1h; (4) The calcined product is ground into powder and mixed with water. After magnetic stirring for 6 hours, the solid-liquid separation is performed by suction filtration to obtain a precursor solution rich in silicon and aluminum elements. Prepare a template aqueous solution (add tetraethyl orthosilicate to tetrabutylammonium hydroxide), stir magnetically for 12 hours at 35°C to completely dissolve it, slowly drop the precursor solution into the template aqueous solution, stir magnetically for 12 hours at room temperature to obtain an initial gel (1SiO2: 0.0125 Al2O3: 0.25 TBAOH: 10 H2O); (5) The obtained initial gel was placed in a polytetrafluoroethylene-lined hydrothermal reactor and subjected to a hydrothermal reaction at 170°C for 48 hours. After the reaction, the solution in the reactor was filtered and washed, and the solid product was placed in an oven at 105°C for 12 hours to fully remove moisture. It was then placed in a muffle furnace and heated to 550°C at a heating rate of 10°C / min and maintained for 6 hours to remove the template and then ground into powder.

[0043] Figure 4 The wide-angle XRD diffraction pattern of the ZSM molecular sieve synthesized in Example 2 of the present invention is shown in FIG. Figure 4 It can be seen that the diffraction peaks of this series of zeolite samples are at 2θ:, 14.95, 23.30, 24.01 and 45.4, and the corresponding planes are (112), (221), (031) and (522), which are close to the ZSM-11 phase structure and conform to the MEL type topological structure. This is also one of the typical characteristics of ZSM-11 molecular sieves.

[0044] Figure 5 This is a transmission electron microscopy (SEM) image of the ZSM molecular sieve synthesized in Example 2 of the present invention. As can be seen from the image, the morphology of the ZSM-11 catalyst is a rod-like structure, and has coupled intercrystalline and intracrystalline mesoporous structures.

[0045] Figure 6The nitrogen adsorption-desorption isotherm and pore size distribution diagram of the ZSM molecular sieve synthesized in Example 2 of the present invention are shown. The N2 adsorption-desorption curve shows that the steep rise at low relative pressure is attributed to the filling of micropores, while the hysteresis loop indicates the presence of mesopores, which can be reasonably attributed to the intercrystalline voids generated by the agglomeration of single rod-shaped crystals.

[0046] from Figure 4-Figure 6 It can be seen that in Example 2, a ZSM-11 type molecular sieve was prepared.

[0047] Example 3 A method for synthesizing ZSM molecular sieve using retired fan blades comprises the following steps: (1) Cut the retired fan blades into pieces and place them in a tube furnace for pyrolysis at 500 °C for 40 min in an argon atmosphere; (2) then calcining the glass fiber obtained in step (1) at 500° C. in an oxygen atmosphere for 40 minutes to remove residual carbon, thereby obtaining pure glass fiber; (3) Grind the pure glass fiber, mix the glass fiber and potassium hydroxide in a mass ratio of 1:1, and calcine at 550°C for 80 minutes; (4) The calcined product is ground into powder and mixed with water. After magnetic stirring for 6 hours, the solid-liquid separation is performed by suction filtration to obtain a precursor solution rich in silicon and aluminum elements. Prepare a template aqueous solution (add tetraethyl orthosilicate to tetrabutylammonium hydroxide), stir magnetically for 12 hours at 35°C to completely dissolve it, slowly drop the precursor solution into the template aqueous solution, stir magnetically for 8 hours at room temperature to obtain an initial gel; (5) The obtained initial gel was placed in a polytetrafluoroethylene-lined hydrothermal reactor and subjected to a hydrothermal reaction at 180°C for 72 hours. After the reaction, the solution in the reactor was filtered and washed, and the solid product was placed in an oven at 105°C for 12 hours to fully remove moisture. It was then placed in a muffle furnace and heated to 500°C at a heating rate of 10°C / min and maintained for 9 hours to remove the template and then ground into powder.

[0048] Example 4 A method for synthesizing ZSM molecular sieve using retired fan blades comprises the following steps: (1) Cut the retired fan blades into pieces and place them in a tubular furnace for pyrolysis at 600 °C for 20 min in a nitrogen atmosphere; (2) then calcining the glass fiber obtained in step (1) at 600° C. in an air atmosphere for 20 min to remove residual carbon, thereby obtaining pure glass fiber; (3) Grind the pure glass fiber, mix the glass fiber and sodium carbonate in a mass ratio of 3:1, and calcine at 650°C for 40 minutes; (4) The calcined product is ground into powder and mixed with water. After magnetic stirring for 6 hours, the solid-liquid separation is performed by suction filtration to obtain a precursor solution rich in silicon and aluminum elements. Prepare a template aqueous solution (add tetraethyl orthosilicate to tetrabutylammonium hydroxide), stir magnetically for 12 hours at 35°C to completely dissolve it, slowly drop the precursor solution into the template aqueous solution, stir magnetically for 24 hours at room temperature to obtain an initial gel; (5) The obtained initial gel was placed in a polytetrafluoroethylene-lined hydrothermal reactor and subjected to a hydrothermal reaction at 170°C for 48 hours. After the reaction, the solution in the reactor was filtered and washed, and the solid product was placed in an oven at 105°C for 12 hours to fully remove moisture. It was then placed in a muffle furnace and heated to 700°C at a heating rate of 10°C / min and maintained for 3 hours to remove the template and then ground into powder.

[0049] Example 5 A method for synthesizing ZSM molecular sieve using retired fan blades comprises the following steps: (1) Cut the retired fan blades into pieces and place them in a tubular furnace for pyrolysis at 580 °C for 35 min in a nitrogen atmosphere; (2) then calcining the glass fiber obtained in step (1) at 580° C. in an air atmosphere for 35 minutes to remove residual carbon, thereby obtaining pure glass fiber; (3) Grind the pure glass fiber, mix the glass fiber, sodium hydroxide and potassium hydroxide in a mass ratio of 2:1, and calcine at 600°C for 70 minutes; (4) The calcined product is ground into powder and mixed with water. After magnetic stirring for 6 hours, the solid-liquid separation is performed by suction filtration to obtain a precursor solution rich in silicon and aluminum elements. Prepare a template aqueous solution (add tetraethyl orthosilicate to tetrabutylammonium hydroxide), stir magnetically for 12 hours at 35°C to completely dissolve it, slowly drop the precursor solution into the template aqueous solution, stir magnetically for 16 hours at room temperature to obtain an initial gel; (5) The obtained initial gel was placed in a polytetrafluoroethylene-lined hydrothermal reactor and subjected to a hydrothermal reaction at 180°C for 48 hours. After the reaction, the solution in the reactor was filtered and washed, and the solid product was placed in an oven at 105°C for 12 hours to fully remove moisture. It was then placed in a muffle furnace and heated to 600°C at a heating rate of 10°C / min and maintained for 5 hours to remove the template and then ground into powder.

[0050] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for synthesizing ZSM molecular sieve using retired fan blades, characterized in that: include: The retired fan blades are pyrolyzed and then calcined once to obtain glass fibers; After grinding and crushing, the mixture is mixed with alkali, subjected to secondary calcination, ground, mixed evenly with water, and separated into solid and liquid to obtain a precursor solution containing silicon and aluminum elements; Then it is mixed with the template aqueous solution and the initial gel is obtained after aging; The ZSM molecular sieve is obtained after solid-liquid separation, drying, calcination three times and grinding.

2. The method for synthesizing ZSM molecular sieve using retired fan blades according to claim 1, characterized in that: The pyrolysis temperature is 500-600° C.; the pyrolysis time is 20-40 minutes; and the pyrolysis atmosphere is nitrogen or argon.

3. The method for synthesizing ZSM molecular sieve using retired fan blades according to claim 1, characterized in that: The temperature of the first calcination is 500-600° C.; the time of the first calcination is 20-40 minutes; and the atmosphere of the first calcination is an oxygen-containing atmosphere or air.

4. The method for synthesizing ZSM molecular sieve using retired fan blades according to claim 1, characterized in that: The alkali is at least one of sodium hydroxide, potassium hydroxide and sodium carbonate; the mass ratio of the glass fiber to the alkali is (1-3):

1.

5. The method for synthesizing ZSM molecular sieve using retired fan blades according to claim 1, characterized in that: The temperature of the secondary calcination is 550-650° C.; the time of the secondary calcination is 40-80 min.

6. The method for synthesizing ZSM molecular sieve using retired blower blades according to claim 1, characterized in that: The aging time is 8-24 hours; the template aqueous solution is a mixture of tetrapropylammonium hydroxide or tetraethyl orthosilicate drops and tetrabutylammonium hydroxide.

7. The method for synthesizing ZSM molecular sieve using retired fan blades according to claim 1, characterized in that: The temperature of the three calcinations is 500-700° C.; the time of the three calcinations is 3-9 hours; and the heating rate is 10° C. / min.

8. The method for synthesizing ZSM molecular sieve using retired blower blades according to claim 1, characterized in that: The retired wind turbine blades contain 20-30wt% resin, 60-70wt% glass fiber and a small amount of structural adhesive; the glass fiber contains silicon dioxide, aluminum oxide and calcium oxide.

9. A ZSM molecular sieve, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the ZSM molecular sieve prepared by the method for synthesizing ZSM molecular sieve using retired wind turbine blades as claimed in any one of claims 1 to 8 in preparing an adsorbent.

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