Waste wind power blade recovery process

Abstract

The invention discloses a waste wind power blade recycling process. The waste wind power blade recycling process comprises the following steps that S1, a waste wind power blade is cut into blocks; wherein manufacturing materials of the waste wind power blade comprise carbon fibers and epoxy resin; s2, the block is put into a swelling solution to be subjected to swelling treatment; wherein the swelling liquid comprises a swelling agent and a solvent, the swelling agent is an inorganic metal chloride, the solvent is composed of acetone and water, in the solvent, the mass percentage of acetone is 10-40%, the mass percentage of water is 60-90%, and in the swelling liquid, the molar concentration of the swelling agent is 0.004-0.1 M; s3, cracking the block subjected to swelling treatment to obtain a cracking product containing the inorganic filler and the carbon fiber material; and S4, recycling the carbon fiber material in the cracking product. The recycling process has the advantages of being efficient, environmentally friendly, low in cost and the like, and is suitable for large-scale resource recycling of the wind power blades.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy technology, and in particular to a waste wind turbine blade recycling process. Background Art

[0002] With the increasing global demand for renewable energy, the wind power industry has developed rapidly. However, wind turbine blades, as an important component of wind power generation equipment, are usually made of difficult-to-degrade composite materials. These materials put tremendous pressure on the environment after being discarded. In the existing technology, the recycling and treatment of wind turbine blades mainly adopt mechanical recycling, high-temperature pyrolysis and other methods, but there are the following problems: (1) Low recycling value: the existing technology is difficult to efficiently recycle carbon fiber materials, resulting in waste of resources; (2) High processing cost: high-temperature pyrolysis and other processes have high energy consumption, which increases the processing cost; (3) High risk of environmental pollution: the existing technology will produce a large amount of harmful gases during the processing process, causing secondary pollution to the environment. Therefore, there is an urgent need to develop an efficient and environmentally friendly wind turbine blade recycling and processing process to solve the above problems.

[0003] It should be noted that the information disclosed in the above background technology section is only used to understand the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for recycling discarded wind turbine blades.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A waste wind turbine blade recycling process includes the following steps:

[0007] S1. Cutting discarded wind turbine blades into blocks; wherein the discarded wind turbine blades are made of materials including carbon fiber and epoxy resin;

[0008] S2. placing the block into a swelling solution for swelling treatment; wherein the swelling solution comprises a swelling agent and a solvent, the swelling agent is an inorganic metal chloride, the solvent comprises acetone and water, the mass percentage of acetone in the solvent is 10-40%, the mass percentage of water is 60-90%, and the molar concentration of the swelling agent in the swelling solution is 0.004-0.1M;

[0009] S3, cracking the block after the swelling treatment to obtain a cracking product containing inorganic filler and carbon fiber material;

[0010] S4. Recovering the carbon fiber material in the pyrolysis product.

[0011] Preferably, in step S1, the discarded wind turbine blades are cleaned and cut using a high-pressure water cleaning module and mechanical cutting equipment to remove surface dirt and attachments, and the cut blocks are separated from the surface dirt using a vibration screening system.

[0012] Preferably, in step S2, the inorganic metal chloride is one of zinc chloride, magnesium chloride, and aluminum chloride, wherein: when the inorganic metal chloride is zinc chloride, the molar concentration of zinc chloride is 0.03-0.1M; when the inorganic metal chloride is magnesium chloride, the molar concentration of magnesium chloride is 0.04-0.06M; when the inorganic metal chloride is aluminum chloride, the molar concentration of aluminum chloride is 0.004-0.006M.

[0013] Preferably, in step S2, the block is placed in a swelling liquid and subjected to swelling treatment in a swelling reactor. The process parameters of the swelling treatment are: controlling the volume ratio of the mass of the block to the swelling liquid to be 45-55 g / L, heating the swelling liquid to 260-300° C. within 25-35 minutes for swelling for 1-2 hours, and then cooling the swelling reactor to room temperature using air convection for 1-2 hours.

[0014] Preferably, the swelling liquid is heated by using a hot tail gas source from a thermal power plant through a spiral heat exchange tube.

[0015] Preferably, in step S3, the cracking is carried out in a fixed bed gasifier, and the cracking temperature is maintained at a predetermined temperature within the range of 360-400°C ±5°C for 1-2 hours.

[0016] Preferably, in step S4, the tail gas generated by cracking is purified and then discharged.

[0017] Preferably, in step S4, the inorganic filler and the carbon fiber material in the pyrolysis product are separated by a vibrating screen machine, the inorganic filler is treated as waste, and the carbon fiber material is recycled and reused.

[0018] Preferably, the fixed-bed gasifier is equipped with a multi-stage temperature sensor and an airflow regulating valve. The multi-stage temperature sensors are arranged in the upper, middle and lower zones of the furnace body of the fixed-bed gasifier, and are used to monitor the temperature in the furnace in real time and provide feedback to the airflow regulating valve. The airflow regulating valve is connected to the flue gas duct of the thermal power plant, and is used to adjust the air intake of the tail gas from the flue gas duct of the thermal power plant into the fixed-bed gasifier according to temperature feedback to control the cracking temperature.

[0019] Preferably, in step S4, the tail gas generated by cracking is purified by an exhaust gas circulation system, and the exhaust gas circulation system includes a dust collector, a second airflow regulating valve and a flue gas purification interface. The dust collector is connected to the outlet of the fixed bed gasification furnace to purify the tail gas generated by cracking, and the outlet of the dust collector is connected to the flue gas purification interface through the second airflow regulating valve. The airflow rate of the purified tail gas is adjusted by the second airflow regulating valve and then returned to the emission system of the thermal power plant through the flue gas purification interface for discharge.

[0020] The present invention has the following beneficial effects: the present invention fully realizes the effective combination of chemical degradation and thermal degradation through the innovative swelling and low-temperature cracking technology, realizes the efficient decomposition and resource recovery of discarded wind turbine blades, reduces processing costs, reduces environmental pollution, and contributes to the sustainable development of the wind power industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the waste wind turbine blade recycling process according to Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present invention in detail. It should be emphasized that the following description is merely illustrative and is not intended to limit the scope and application of the present invention. The embodiments and features in the embodiments of this application may be combined with each other unless there is a conflict. In this document, room temperature refers to 25-35°C.

[0023] The specific embodiment of the present invention provides a waste wind turbine blade recycling process, including the following steps:

[0024] S1. Cutting discarded wind turbine blades into blocks; wherein the discarded wind turbine blades are made of materials including carbon fiber and epoxy resin;

[0025] S2. placing the block into a swelling solution for swelling treatment; wherein the swelling solution comprises a swelling agent and a solvent, the swelling agent is an inorganic metal chloride, the solvent comprises acetone and water, the mass percentage of acetone in the solvent is 10-40%, the mass percentage of water is 60-90%, and the molar concentration of the swelling agent in the swelling solution is 0.004-0.1M;

[0026] S3, cracking the block after the swelling treatment to obtain a cracking product containing inorganic filler and carbon fiber material;

[0027] S4. Recovering the carbon fiber material in the pyrolysis product.

[0028] In the above technical solution, the inorganic metal chloride forms a stable complex with the carbonyl group of acetone, reducing the concentration of free metal ions and enhancing solubility. At the same time, the solvent composed of acetone and water has a low viscosity, which facilitates stirring and mass transfer. The above-mentioned specific swelling liquid is a swelling degradation catalyst for discarded wind turbine blades, which helps the epoxy resin to achieve depolymerization at a lower reaction temperature.

[0029] In some embodiments, in step S1, the discarded wind turbine blades are cleaned and cut using a high-pressure water cleaning module and mechanical cutting equipment to remove surface dirt and attachments, and the cut blocks and surface dirt are separated using a vibration screening system.

[0030] In some embodiments, in step S2, the inorganic metal chloride is one of zinc chloride, magnesium chloride, and aluminum chloride, wherein: when the inorganic metal chloride is zinc chloride, the molar concentration of zinc chloride is 0.03-0.1M; when the inorganic metal chloride is magnesium chloride, the molar concentration of magnesium chloride is 0.04-0.06M; when the inorganic metal chloride is aluminum chloride, the molar concentration of aluminum chloride is 0.004-0.006M.

[0031] In some embodiments, in step S2, the block is placed in a swelling liquid and subjected to swelling treatment in a swelling reactor. The process parameters of the swelling treatment are: controlling the volume ratio of the mass of the block to the swelling liquid to be 45-55 g / L, heating the swelling liquid to 260-300° C. within 25-35 minutes for swelling for 1-2 hours, and then cooling the swelling reactor to room temperature using air convection for 1-2 hours.

[0032] In some embodiments, the swelling liquid is heated by using a hot tail gas source from a thermal power plant through a spiral heat exchange tube.

[0033] In some embodiments, in step S3, the cracking is performed in a fixed bed gasifier, with the cracking temperature maintained at a predetermined temperature within the range of 360-400°C ±5°C for 1-2 hours.

[0034] In some embodiments, in step S4, the tail gas generated by cracking is purified and then discharged.

[0035] In some embodiments, in step S4, the inorganic filler and the carbon fiber material in the pyrolysis product are separated by a vibrating screen, the inorganic filler is treated as waste, and the carbon fiber material is recycled and reused.

[0036] In some embodiments, the fixed bed gasifier is equipped with a multi-stage temperature sensor and an airflow regulating valve. The multi-stage temperature sensor is arranged in the upper, middle and lower zones of the furnace body of the fixed bed gasifier, and is used to monitor the temperature in the furnace in real time and provide feedback to the airflow regulating valve. The airflow regulating valve is connected to the flue gas duct of the thermal power plant, and is used to adjust the intake volume of the exhaust gas from the flue gas duct of the thermal power plant into the fixed bed gasifier according to temperature feedback to control the cracking temperature.

[0037] In some embodiments, in step S4, the tail gas generated by cracking is purified by an exhaust gas circulation system, and the exhaust gas circulation system includes a dust collector, a second airflow regulating valve and a flue gas purification interface. The dust collector is connected to the outlet of the fixed bed gasification furnace to purify the tail gas generated by cracking, and the outlet of the dust collector is connected to the flue gas purification interface through the second airflow regulating valve. The airflow rate of the purified tail gas is adjusted by the second airflow regulating valve and then returned to the emission system of the thermal power plant through the flue gas purification interface for discharge.

[0038] Specific embodiments of the present invention are further described below.

[0039] Example 1

[0040] A waste wind turbine blade recycling process, wherein the waste wind turbine blades are made of carbon fiber and epoxy resin, includes the following steps:

[0041] 1. Preprocessing steps

[0042] This pretreatment step uses high-pressure water cleaning and vibration screening to accurately remove impurities. Specifically, a high-pressure water cleaning module and mechanical cutting equipment are used to clean and cut the blades to remove surface dirt and attachments. The cut blocks and surface dirt are separated by a vibration screening system. The water pressure in the high-pressure water cleaning module is set to 50-100MPa, and the mechanical cutting equipment uses a tungsten steel blade with a cutting accuracy of ±1mm. The discarded wind turbine blades are cut into 10×10×10±1mm pieces. 3 the vibrating screening system is driven by a variable frequency motor (the screen aperture 0.5-2mm (1mm in this case), the vibration frequency 30-50Hz, the separation efficiency ≥95%), and the cut blocks are separated from the surface dirt.

[0043] 2. Swelling step

[0044] The swelling step uses an acetone-water solution of zinc chloride, magnesium chloride, aluminum chloride, etc. in a specific ratio, and combines exhaust heat recovery technology and a solid-liquid ratio control device to improve efficiency. Specifically, the block obtained after the pretreatment step is placed in a steam-heated reactor filled with a swelling liquid (the steam-heated reactor serves as a swelling reactor) for swelling treatment; wherein the swelling liquid includes a swelling agent and a solvent, the swelling agent is zinc chloride, and the solvent is composed of acetone and water, in which the mass percentage of acetone is 20%, the mass percentage of water is 80%, and the molar concentration of the swelling agent is 0.01M; in this swelling step, the steam-heated reactor includes a steam heating system, an exhaust heat recovery pipe, and a solid-liquid ratio control device, the exhaust heat recovery pipe is connected to the hot exhaust gas source of the thermal power plant, and the steam heating system is a spiral heat exchange pipe, that is, 300-350°C exhaust gas is introduced from the flue gas duct of the thermal power plant through the exhaust heat recovery pipe, and the swelling liquid is heated by the spiral heat exchange pipe, reducing energy consumption by 30%. To prevent the blocks from contacting the inner walls of the steam-heated reactor and causing degradation and loss, the solid-to-liquid ratio control device, linked to the reactor's feed port via a liquid level sensor, maintains a mass-to-volume ratio of 50 g / L for the solid (block) to liquid (swelling liquid) in the steam-heated reactor. The heating phase is set to 30 minutes, with the temperature raised to 300°C for 1 hour of swelling, followed by 1-2 hours of cooling the reactor to room temperature using air convection.

[0045] 3. Cracking step

[0046] The cracking is carried out in a fixed-bed gasifier with multi-stage temperature control, achieving low-temperature cracking (360-400°C) and ensuring that the strength retention ratio of the recycled fiber is ≥90%. Specifically, the block after the swelling treatment is cracked in a fixed-bed gasifier for 1 hour. The fixed-bed gasifier is equipped with multi-stage temperature sensors and airflow regulating valves. The multi-stage temperature sensors are arranged in the upper, middle and lower zones of the furnace body of the fixed-bed gasifier for real-time monitoring of the temperature in the furnace and feedback to the airflow regulating valve. The airflow regulating valve is connected to the flue gas pipe of the thermal power plant and is used to adjust the air intake according to temperature feedback (adjust the amount of tail gas from the flue gas pipe of the thermal power plant entering the fixed-bed gasifier to control the cracking temperature) to maintain a cracking temperature of 400°C. After cracking, a cracking product containing inorganic fillers and carbon fiber materials is obtained.

[0047] 4. Tail gas treatment and material recovery steps

[0048] In this step, the tail gas is reused and discharged after being treated, which can reduce energy consumption and environmental pollution. Specifically, the tail gas treatment and material recovery steps include a tail gas circulation system and a vibrating screen. The tail gas circulation system includes a dust collector, a second air flow regulating valve and a flue gas purification interface. The dust collector is connected to the outlet of the above-mentioned fixed bed gasification furnace to purify the tail gas generated by cracking. The outlet of the dust collector is connected to the flue gas purification interface through the second air flow regulating valve. The air flow rate of the purified tail gas (mainly including carbon dioxide, water vapor and nitrogen) is adjusted by the second air flow regulating valve and then returned to the emission system of the thermal power plant through the flue gas purification interface for discharge. The vibrating screen is used to separate the inorganic filler and carbon fiber material in the cracking product, and the inorganic filler is treated as waste, and the carbon fiber material is recycled and reused. For example, the carbon fiber material is purified and reprocessed and recycled into a recycled composite material. The recycled composite material can be used to produce new wind turbine blades or other composite products.

[0049] In Example 1, the waste heat from the flue gas duct of a thermal power plant is used to provide heat for the swelling and cracking of discarded wind turbine blades, thereby reducing technical operating costs and energy consumption. At the same time, the gas after the reaction can be purified again to meet emission standards or recycled.

[0050] Example 2-12

[0051] The following table lists the differences between Examples 2-12 and Example 1, and the other differences are the same as Example 1. The differences are shown in Table 1 below:

[0052] Table 1:

[0053]

[0054]

[0055] The recycling effect in Examples 1-12 is represented by the resin cracking rate of the epoxy resin and the strength retention ratio of the recycled carbon fiber material (i.e., the strength retention ratio of the recycled fiber). The resin cracking rate is calculated as shown in the following formula (1), and the strength retention ratio of the recycled fiber is calculated as shown in the following formula (2):

[0056] (1)η=(1-W f2 / W f1 )×100%

[0057] Wherein, η represents the resin cracking rate of epoxy resin, %; W f1 W represents the initial mass percentage of epoxy resin in the composite material of discarded wind turbine blades, %; f2 It represents the mass percentage of epoxy resin in the cracking product, %.

[0058] (2) x = R1 / R0 × 100%

[0059] Wherein, x represents the strength retention ratio of the recycled fiber, %; R0 represents the tensile strength of the original carbon fiber (this value is known when the wind blade leaves the factory. The carbon fiber in the discarded wind blade in this example uses TC35R brand (48K) carbon fiber with a strength of 4.0 GPa produced by Formosa Plastics Corporation in Taiwan, China), GPa; R1 represents the tensile strength of the recycled fiber, GPa.

[0060] Among them, W f1 and W f2 The measurement was made by semi-quantitative analysis using infrared spectroscopy (FTIR). The measurement principle is to estimate the content of epoxy resin by comparing the characteristic peak intensity (COC bond of epoxy resin 1240 cm-1) with the standard curve, which includes the following measurement steps: (1) Standard sample preparation: mixing epoxy resin with a known ratio with carbon fiber material to make a standard sample; (2) Spectrum acquisition: using FTIR to measure the characteristic peak area of the standard sample and the cracking product; (3) Establishing a standard curve: plotting a curve based on peak area-resin content; (4) Analysis: substituting the peak area of the material to be measured (such as the composite material of discarded fan blades, cracking products) into the curve to calculate the epoxy resin content in the material. The mass percentage of epoxy resin in the composite material of discarded fan blades measured in the embodiment is W f1 is 35%, the mass percentage of epoxy resin in the cracking product is W f2 As shown in Table 2 below.

[0061] The tensile strength of recycled fiber refers to the maximum stress that the fiber can withstand before breaking. The calculation formula is: σ = A / Fmax, σ is the tensile strength (MPa); Fmax is the maximum tensile force at break (N); A is the fiber cross section (mm 2), obtained by diameter measurement or linear density calculation. The test steps of R1 are as follows: (1) Sample preparation: (1.1) Fiber extraction: The recovered carbon fiber material is ultrasonically cleaned to remove residual contaminants on the surface, and then dried for use; (1.2) Fiber fixing: A single fiber is glued to a standard paper frame (25 mm spacing) using low-viscosity glue (such as epoxy glue to prevent the glue from penetrating into the test section) to ensure that the fiber is straight and without bending; (2) Diameter measurement: Using a laser diameter gauge, measure three times at different positions on the fiber and take the average value; (3) Clamping and centering: Fix the standard paper frame on the test machine fixture, cut off both sides of the standard paper frame, and only retain the fiber test section to ensure that the fiber is strictly aligned with the tensile direction to avoid eccentric loading; (4) Tensile test. Parameter setting: Tensile rate: 1–5 mm / min (strain rate 1% / s). Initial gauge length (Gauge Length) is 25 mm (ASTM standard). Data acquisition: Real-time recording of the tension-displacement curve until the fiber breaks. The tensile strength R1 of the recycled fibers measured in the examples is shown in Table 2 below.

[0062] The resin cracking rates and the recovered fiber strength retention ratios of Examples 1-12 are shown in Table 2 below.

[0063] Table 2:

[0064]

[0065] From the above, it can be seen that in the embodiment of the present invention, the acetone aqueous solution of metal chloride catalyzes the swelling of the discarded wind turbine blades and then realizes the cracking of C=N bonds in the epoxy resin at low temperature. Acetone aqueous solutions of zinc chloride, magnesium chloride, aluminum chloride, etc. show high catalytic properties (as shown in the resin cracking rate in Table 2). When the swelling temperature is 300°C, the swelling time is 1h, the cracking temperature is 400°C, and the cracking time is 1h, as the molar concentration of ZnCl2 increases, the resin cracking rate rapidly increases to 97% and enters a plateau period of more than 83%. When the swelling temperature and cracking temperature are lowered, it is necessary to extend the time to increase the resin cracking rate. The embodiment of the present invention compared ZnCl2 and AlCl3 and found that the required concentration of the swelling agent AlCl3 is the lowest, which is only 10% of ZnCl2 and MgCl2 at the same resin cracking rate and recycled material fiber strength retention ratio. This is because Al 3+ The ions carry a stronger charge, so they can interact more strongly with the lone pairs of electrons on heteroatoms within the molecular structure, and more strongly with the C=N bond. Furthermore, because the low-temperature pyrolysis process used minimizes damage to the fiber strength of the carbon fiber material, the strength retention of the recycled fiber is over 90%.

[0066] The recycling process of the present invention has the advantages of high efficiency, environmental protection, and low cost, and is suitable for large-scale resource recovery of wind turbine blades, thereby realizing the circular utilization of resources. Specifically, the implementation of the present invention has the following significant beneficial effects:

[0067] (1) Reduced energy consumption: The swelling reactor with integrated tail gas waste heat recovery reduces energy consumption by 30%. The fixed-bed gasifier with multi-stage temperature control precisely maintains low-temperature cracking conditions. Lowering the thermal degradation temperature is beneficial to the stability of the material structure and makes large-scale processing possible.

[0068] (2) Process innovation: High-pressure water cleaning and vibration screening work together to accurately remove impurities, improving pretreatment efficiency by 50%; low-concentration and efficient utilization of swelling agents such as AlCl3 (0.005M can achieve a 94% cracking rate), while the specially prepared swelling fluid produces few by-products during the swelling process, which has little impact on the environment.

[0069] (3) Economic and environmentally friendly: Using treated exhaust gas from thermal power plants as a heat source reduces processing costs and improves resource recovery, which will bring significant economic benefits to the wind power industry and promote its sustainable development. The exhaust gas circulation system achieves near-zero pollutant emissions; the carbon fiber strength retention ratio is ≥90%, which can be directly used for recycled composite materials, which is very beneficial for the recycling of wind turbine blades.

[0070] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the scope of protection of the patent application.

Claims

1. A waste wind turbine blade recycling process, characterized in that: The steps include: S1. Cutting discarded wind turbine blades into blocks; wherein the discarded wind turbine blades are made of materials including carbon fiber and epoxy resin; S2. placing the block into a swelling solution for swelling treatment; wherein the swelling solution comprises a swelling agent and a solvent, the swelling agent is an inorganic metal chloride, the solvent comprises acetone and water, the mass percentage of acetone in the solvent is 10-40%, the mass percentage of water is 60-90%, and the molar concentration of the swelling agent in the swelling solution is 0.004-0.1M; S3, cracking the block after the swelling treatment to obtain a cracking product containing inorganic filler and carbon fiber material; S4. Recovering the carbon fiber material in the pyrolysis product.

2. The waste wind turbine blade recycling process according to claim 1, characterized in that: In step S1, the discarded wind turbine blades are cleaned and cut using a high-pressure water cleaning module and mechanical cutting equipment to remove surface dirt and attachments, and the cut blocks and surface dirt are separated using a vibration screening system.

3. The waste wind turbine blade recycling process according to claim 1, characterized in that: In step S2, the inorganic metal chloride is one of zinc chloride, magnesium chloride, and aluminum chloride, wherein: When the inorganic metal chloride is zinc chloride, the molar concentration of zinc chloride is 0.03-0.1M; When the inorganic metal chloride is magnesium chloride, the molar concentration of magnesium chloride is 0.04-0.06M; When the inorganic metal chloride is aluminum chloride, the molar concentration of aluminum chloride is 0.004-0.006M.

4. The waste wind turbine blade recycling process according to claim 1, characterized in that: In step S2, the block is placed in a swelling liquid and subjected to swelling treatment in a swelling reactor. The process parameters of the swelling treatment are as follows: controlling the volume ratio of the mass of the block to the swelling liquid to be 45-55 g / L, heating the swelling liquid to 260-300° C. within 25-35 minutes for swelling for 1-2 hours, and then cooling the swelling reactor to room temperature using air convection for 1-2 hours.

5. The waste wind turbine blade recycling process according to claim 4, characterized in that: The hot tail gas source of the thermal power plant is used to heat the swelling liquid through the spiral heat exchange tube.

6. The waste wind turbine blade recycling process according to claim 1, characterized in that: In step S3, the cracking is carried out in a fixed bed gasifier, with the cracking temperature maintained at a predetermined temperature within the range of 360-400°C ±5°C for 1-2 hours.

7. The waste wind turbine blade recycling process according to claim 6, characterized in that: In step S4, the tail gas generated by the cracking is purified and then discharged.

8. The waste wind turbine blade recycling process according to claim 1, characterized in that: In step S4, the inorganic filler and the carbon fiber material in the pyrolysis product are separated by a vibrating screen machine, the inorganic filler is treated as waste, and the carbon fiber material is recycled and reused.

9. The waste wind turbine blade recycling process according to claim 6, characterized in that: The fixed-bed gasifier is equipped with multi-stage temperature sensors and an airflow regulating valve. The multi-stage temperature sensors are arranged in the upper, middle and lower zones of the furnace body of the fixed-bed gasifier and are used to monitor the temperature in the furnace in real time and provide feedback to the airflow regulating valve. The airflow regulating valve is connected to the flue gas pipeline of the thermal power plant and is used to adjust the intake volume of the tail gas from the flue gas pipeline of the thermal power plant into the fixed-bed gasifier according to temperature feedback to control the cracking temperature.

10. The waste wind turbine blade recycling process according to claim 7, characterized in that: In step S4, the tail gas generated by cracking is purified by an exhaust gas circulation system, and the exhaust gas circulation system includes a dust collector, a second airflow regulating valve and a flue gas purification interface. The dust collector is connected to the outlet of the fixed bed gasification furnace to purify the tail gas generated by cracking. The outlet of the dust collector is connected to the flue gas purification interface through the second airflow regulating valve. The airflow rate of the purified tail gas is adjusted by the second airflow regulating valve and then returned to the emission system of the thermal power plant through the flue gas purification interface for discharge.

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