Pyrolysis recovery method of waste photovoltaic module

Abstract

The invention provides a pyrolysis recovery method of a waste photovoltaic module, and relates to the technical field of photovoltaic panel recovery, the method comprises the following steps: pre-disassembling to obtain an aluminum frame, a junction box and a multilayer board; the multilayer board is conveyed to a pyrolysis tunnel furnace, and pyrolysis gas and a pyrolysis multilayer board are obtained; wherein the temperature in the furnace is 200-380 DEG C; classifying the pyrolyzed multilayer boards to obtain complete pyrolyzed boards and fragmented pyrolyzed boards; disassembling the complete pyrolysis plate to obtain first EVA pyrolysis residues, a complete glass plate, a complete battery silicon wafer and a complete back plate; the fragmented pyrolysis plate is cut, and pyrolysis particles are obtained; sorting the pyrolysis particles to obtain second EVA pyrolysis residues, glass particles, battery silicon wafer particles and backboard particles; the first EVA pyrolysis residues and the second EVA pyrolysis residues are mixed, and mixed pyrolysis residues are obtained; conveying the mixed pyrolysis residues to a pyrolysis tunnel furnace to obtain an olefin mixture and third pyrolysis residues; wherein the temperature in the furnace is 500-600 DEG C;

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic panel recycling, and in particular to a pyrolysis recycling method for waste photovoltaic components. Background Art

[0002] In recent years, photovoltaic power generation technology has developed rapidly. The life of photovoltaic modules is about 25 years, and it is expected that there will be a wave of photovoltaic module scrapping. Wasted photovoltaic modules contain valuable components such as glass, silicon wafers, silver, and copper, and their recycling has certain economic value.

[0003] At present, high-temperature pyrolysis is usually used to destroy the adhesive (EVA) between the glass plate and the silicon wafer to achieve the separation of the glass plate and the silicon wafer. Since the photovoltaic module not only contains photovoltaic glass, battery silicon wafers and EVA film, but also contains a backplane; among which the backplane is mainly a multi-layer structure with fluoroplastic as the outer protective layer. When the photovoltaic module is in a high-temperature pyrolysis environment for a long time, a large amount of fluoride will be generated, which not only pollutes the environment, but also affects the secondary utilization of recyclables. Summary of the invention

[0004] The purpose of the present invention is to provide a method for pyrolysis recovery of waste photovoltaic modules, and the technical problem to be solved is how to reduce the generation of fluoride and improve the utilization value of the recovered materials.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for pyrolysis recovery of waste photovoltaic modules, comprising the following steps:

[0007] S100, pre-disassembling the above-mentioned discarded photovoltaic components to obtain aluminum frames, junction boxes and multilayer boards;

[0008] S200, transporting the multilayer board to a pyrolysis tunnel furnace to obtain pyrolysis gas and pyrolysis multilayer board; wherein the temperature in the pyrolysis tunnel furnace is controlled at 200-380°C;

[0009] S300, classifying the pyrolysis multilayer boards to obtain complete pyrolysis boards and broken pyrolysis boards;

[0010] S400, disassembling the complete pyrolysis plate to obtain a first EVA pyrolysis residue, a complete glass plate, a complete battery silicon wafer and a complete backplane;

[0011] S500, cutting the fragmented pyrolysis plate to obtain pyrolysis particles;

[0012] The pyrolysis particles are sorted to obtain second EVA pyrolysis residue, glass particles, battery silicon wafer particles and backplane particles;

[0013] S600, mixing the first EVA pyrolysis residue and the second EVA pyrolysis residue to obtain a mixed pyrolysis residue; conveying the mixed pyrolysis residue to a pyrolysis tunnel furnace to obtain an olefin mixture and a third pyrolysis residue; wherein the temperature in the pyrolysis tunnel furnace is controlled at 500-600°C.

[0014] Two pyrolysis steps (S200 and S600) with different temperature ranges are adopted. First, preliminary pyrolysis is carried out at a relatively low temperature (200-380°C) to effectively remove EVA (ethylene-vinyl acetate copolymer), so that the bonding force between the multilayer board structures is weakened, and the backboard is prevented from being exposed to a high temperature environment for a long time, thereby reducing the possibility of fluoropolymer decomposition into fluoride; after low-temperature pyrolysis, the complete backboard or backboard particles are separated from other materials by physical disassembly (S400) or cutting (S500), ensuring that the backboard containing fluoropolymer will not enter the higher temperature secondary pyrolysis stage (S600), further reducing the risk of fluoride generation; the first EVA pyrolysis residue and the second EVA pyrolysis residue are mixed and then sent to a pyrolysis tunnel furnace at a higher temperature (500-600°C) for treatment, decomposing into an olefin mixture to achieve olefin recovery (olefin is an important substance in the chemical and energy industries). Traditional high-temperature pyrolysis recovery technology usually directly reuses pyrolysis gas as energy, resulting in a great waste of the value of recycled materials. Because most of the fluorine-containing backing material has been removed at this time, even if pyrolysis is carried out at a higher temperature, the emission of fluorides will not be significantly increased.

[0015] Furthermore, the specific steps of sorting the pyrolysis particles in the above S500 include:

[0016] S510, screening the pyrolysis particles by a screening device to obtain a second EVA pyrolysis residue and first particles to be separated;

[0017] S520, separating the first particles to be separated by a liquid medium to obtain backplane particles and second particles to be separated;

[0018] S530, separating the second particles to be separated by airflow to obtain glass particles and battery silicon wafer particles.

[0019] The second EVA pyrolysis residue is separated from other materials in advance to prevent the second EVA pyrolysis residue from affecting the secondary pyrolysis after being soaked in water. It also prevents the second EVA pyrolysis residue from carrying backplane particles after being soaked in water, thereby reducing the fluoride produced during the secondary pyrolysis. The liquid medium separation technology can be used to effectively separate the backplane particles from other materials according to the density differences of different materials, ensuring that the fluorine-containing backplane material is collected separately, avoiding the backplane particles from entering the high-temperature treatment link, thereby reducing the emission of fluorides. The airflow separation can separate the glass particles and the battery silicon wafer particles according to their shapes and weights, thereby ensuring the recycling of the two materials.

[0020] Furthermore, the temperature distribution in the pyrolysis tunnel furnace in the above S200 is: first rising and then falling along the multilayer board conveying path.

[0021] When entering the pyrolysis tunnel furnace, the multilayer board first encounters a gradually rising temperature zone. This process allows the material to have a gentle preheating stage, which helps to avoid internal stress or physical damage to the material caused by sudden temperature changes. As the multilayer board goes deeper into the furnace, the temperature reaches a peak (no more than 380°C), at which time EVA and other organic binders are in the best pyrolysis conditions and can be effectively decomposed into gas and solid residues without excessive decomposition to produce unnecessary by-products or harmful substances. After the main pyrolysis reaction is completed in the higher temperature section, the temperature begins to drop, which not only protects the fluoropolymer in the backsheet from long-term high temperature and reduces the risk of fluoride formation, but also helps to preserve the integrity of the backsheet for subsequent separation and processing. By controlling the temperature of the cooling zone, it is ensured that the pyrolyzed material has cooled to a relatively safe temperature before leaving the furnace, reducing the energy consumption required for external cooling. The gradually decreasing temperature helps to maintain the structural integrity of the pyrolyzed material, especially for fragile components such as glass panels and battery silicon wafers, to prevent them from breaking or being damaged due to sudden cooling. The material integrity makes subsequent physical sorting (such as screening, liquid medium separation and air flow separation) easier to carry out, improving the recovery rate and purity of various materials.

[0022] Furthermore, the temperature distribution in the pyrolysis tunnel furnace in the above S600 is as follows: it gradually increases along the multilayer board conveying path.

[0023] The gradually increasing temperature distribution along the conveying path allows the EVA pyrolysis residue to have a gradual temperature increase process before entering the higher temperature area, which helps to even out the temperature inside the material, reduce the thermal stress caused by excessive temperature gradient, and avoid material rupture or structural damage; because the temperature rises gradually, the low-temperature area at the front end can absorb the heat from the high-temperature area at the rear end, achieve a certain degree of heat recycling, and reduce overall energy consumption; in addition, it is also possible to consider using the generated pyrolysis gas to heat the material at the front end to further improve the energy efficiency of the system.

[0024] Furthermore, the time for the multilayer board to pass through the pyrolysis tunnel furnace is 15 to 70 minutes.

[0025] The time range of 15 to 70 minutes is sufficient for the multilayer board to undergo sufficient pyrolysis reaction in different temperature ranges. In the S200 stage (200-380°C), it can ensure that EVA and other organic binders have enough time to decompose into gas and solid residues without incomplete pyrolysis due to too short a residence time. In the S600 stage (500-600°C), a residence time of 15 to 70 minutes allows the mixed EVA pyrolysis residue to undergo a gradual heating process from low temperature to high temperature, which helps to achieve uniform temperature distribution, promote more complete decomposition reactions, and reduce material stress caused by sudden temperature changes.

[0026] Furthermore, the battery silicon wafer particles are immersed in an alkaline solution to remove the aluminum electrode;

[0027] The battery silicon wafer particles from which the aluminum electrode and the silver electrode have been removed are immersed in an acid solution to remove the silver electrode and the anti-reflection layer.

[0028] Furthermore, the alkaline solution is sodium hydroxide solution or potassium hydroxide solution; the acidic solution is any one of nitric acid, hydrochloric acid, phosphoric acid and hydrofluoric acid solution.

[0029] The above-mentioned aluminum electrode will react with alkali in an alkaline environment to form a soluble aluminum salt, which can be effectively removed. Commonly used alkaline solutions include sodium hydroxide (NaOH) or potassium hydroxide (KOH), which can selectively dissolve aluminum without significantly affecting the silicon wafer itself. After removing the aluminum electrode, the battery silicon wafer particles are immersed in an acidic solution to remove the silver electrode and the anti-reflective coating on the surface. Commonly used acidic solutions may include nitric acid (HNO3), hydrochloric acid (HCl), etc., which can effectively dissolve silver and destroy the anti-reflective layer. After the above-mentioned chemical treatment, the metal electrodes and other non-silicon components on the surface of the battery silicon wafer particles are effectively removed, which greatly improves the purity of the silicon wafer, so that the recycled silicon wafer can be more directly applied to new photovoltaic products or other semiconductor manufacturing fields.

[0030] Furthermore, the pyrolysis gas is condensed to obtain a mixed gas and an acetic acid solution; wherein the mixed gas includes carbon dioxide and argon.

[0031] Condensing pyrolysis gas not only helps to separate and recover valuable chemicals, but also reduces greenhouse gases and other harmful substances emitted into the atmosphere. The pyrolysis gas produced during the pyrolysis process contains a variety of volatile organic compounds (VOCs), water vapor, and some non-condensable gases such as carbon dioxide (CO2) and argon (Ar). The pyrolysis gas is cooled to an appropriate temperature through a condensing device to condense the volatile organic matter and water therein. Valuable chemicals (such as acetic acid, which is an important substance in the chemical and energy industries) can be recovered through effective treatment of the pyrolysis gas.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] Two pyrolysis steps (S200 and S600) with different temperature ranges are adopted. First, preliminary pyrolysis is carried out at a relatively low temperature (200-380°C) to effectively remove EVA (ethylene-vinyl acetate copolymer), so that the bonding force between the multilayer board structures is weakened, and the backboard is prevented from being exposed to a high temperature environment for a long time, thereby reducing the possibility of fluoropolymer decomposition into fluoride; after low-temperature pyrolysis, the complete backboard or backboard particles are separated from other materials by physical disassembly (S400) or cutting (S500), ensuring that the backboard containing fluoropolymer will not enter the higher temperature secondary pyrolysis stage (S600), further reducing the risk of fluoride generation; the first EVA pyrolysis residue and the second EVA pyrolysis residue are mixed and then sent to a pyrolysis tunnel furnace at a higher temperature (500-600°C) for treatment, decomposing into an olefin mixture to achieve olefin recovery (olefin is an important substance in the chemical and energy industries). Traditional high-temperature pyrolysis recovery technology usually directly reuses pyrolysis gas as energy, resulting in a great waste of the value of recycled materials. Because most of the fluorine-containing backing material has been removed at this time, even if pyrolysis is carried out at a higher temperature, the emission of fluorides will not be significantly increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0035] Figure 1 Main flow chart. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0037] First embodiment:

[0038] Combination Figure 1 A method for pyrolysis recovery of waste photovoltaic modules comprises the following steps:

[0039] S100, pre-disassembling the above-mentioned discarded photovoltaic components to obtain aluminum frames, junction boxes and multilayer boards;

[0040] S200, transporting the multilayer board to a pyrolysis tunnel furnace to obtain pyrolysis gas and pyrolysis multilayer board; wherein the temperature in the pyrolysis tunnel furnace is controlled at 200-380°C;

[0041] S300, classifying the pyrolysis multilayer board to obtain a complete pyrolysis board and a broken pyrolysis board; the classification method can use existing image recognition technology to identify cracks on the pyrolysis multilayer board, and if there are cracks, it is defined as a broken pyrolysis board, and if there are no cracks, it is defined as a complete pyrolysis board;

[0042] S400, disassembling the complete pyrolysis plate to obtain a first EVA pyrolysis residue, a complete glass plate, a complete battery silicon wafer and a complete back plate; the complete glass plate, the complete battery silicon wafer and the complete back plate can be directly recycled;

[0043] S500, cutting the fragmented pyrolysis plate to obtain pyrolysis particles;

[0044] The pyrolysis particles are sorted to obtain second EVA pyrolysis residue, glass particles, battery silicon wafer particles and backplane particles;

[0045] S600, mixing the first EVA pyrolysis residue and the second EVA pyrolysis residue to obtain a mixed pyrolysis residue; conveying the mixed pyrolysis residue to a pyrolysis tunnel furnace to obtain an olefin mixture and a third pyrolysis residue; wherein the temperature in the pyrolysis tunnel furnace is controlled at 500-600°C.

[0046] During the recycling process of photovoltaic modules, fluorides are mainly generated from fluoropolymers in the backsheet material. These fluorides are not only harmful to the environment, but also may reduce the efficiency of the recycling process and the quality of the recycled products.

[0047] The above method adopts two pyrolysis steps (S200 and S600) in different temperature ranges. First, preliminary pyrolysis is carried out at a relatively low temperature (200-380°C) to effectively remove EVA (ethylene-vinyl acetate copolymer), so that the bonding force between the multilayer board structures is weakened, and the backboard is prevented from being exposed to a high temperature environment for a long time, thereby reducing the possibility of fluoropolymer decomposition into fluoride; after low-temperature pyrolysis, the complete backboard or backboard particles are separated from other materials by physical disassembly (S400) or cutting (S500), ensuring that the backboard containing fluoropolymer will not enter a higher temperature secondary pyrolysis stage (S600), further reducing the risk of fluoride generation; the first EVA pyrolysis residue and the second EVA pyrolysis residue are mixed and then sent to a pyrolysis tunnel furnace at a higher temperature (500-600°C) for treatment, decomposing into an olefin mixture to achieve olefin recovery (olefin is an important substance in the chemical and energy industries). Traditional high-temperature pyrolysis recovery technology usually directly reuses pyrolysis gas as energy, resulting in a great waste of the value of recycled materials. Because most of the fluorine-containing backing material has been removed at this time, even if pyrolysis is carried out at a higher temperature, the emission of fluorides will not be significantly increased.

[0048] Second embodiment:

[0049] Based on the first embodiment, the specific steps of sorting the pyrolysis particles in S500 include:

[0050] S510, screening the pyrolysis particles by a screening device to obtain a second EVA pyrolysis residue and first particles to be separated, wherein the second EVA pyrolysis residue is in powder form;

[0051] S520. Separate the first particles to be separated by a liquid medium to obtain backplane particles and second particles to be separated. The liquid medium may be a salt solution, and its density is changed by adjusting the concentration of the salt solution to better match the density difference between different materials. The lighter backplane particles float on the water surface, and the heavier glass and metal particles sink to the bottom.

[0052] S530, separating the second particles to be separated by airflow to obtain glass particles and battery silicon wafer particles; wherein the second particles to be separated are cut into approximately the same size.

[0053] The second EVA pyrolysis residue is separated from other materials in advance to prevent the second EVA pyrolysis residue from affecting the secondary pyrolysis after being soaked in water. It also prevents the second EVA pyrolysis residue from carrying backplane particles after being soaked in water, thereby reducing the fluoride produced during the secondary pyrolysis. The liquid medium separation technology can be used to effectively separate the backplane particles from other materials according to the density differences of different materials, ensuring that the fluorine-containing backplane material is collected separately, avoiding the backplane particles from entering the high-temperature treatment link, thereby reducing the emission of fluorides. The airflow separation can separate the glass particles and the battery silicon wafer particles according to their shapes and weights, thereby ensuring the recycling of the two materials.

[0054] Third embodiment:

[0055] Based on any of the above embodiments, the temperature distribution in the pyrolysis tunnel furnace in the above S200 is: first rising and then falling along the multilayer board conveying path.

[0056] When entering the pyrolysis tunnel furnace, the multilayer board first encounters a gradually rising temperature zone. This process allows the material to have a gentle preheating stage, which helps to avoid internal stress or physical damage to the material caused by sudden temperature changes. As the multilayer board goes deeper into the furnace, the temperature reaches a peak (no more than 380°C), at which time EVA and other organic binders are in the best pyrolysis conditions and can be effectively decomposed into gas and solid residues without excessive decomposition to produce unnecessary by-products or harmful substances. After the main pyrolysis reaction is completed in the higher temperature section, the temperature begins to drop, which not only protects the fluoropolymer in the backsheet from long-term high temperature and reduces the risk of fluoride formation, but also helps to preserve the integrity of the backsheet for subsequent separation and processing. By controlling the temperature of the cooling zone, it is ensured that the pyrolyzed material has cooled to a relatively safe temperature before leaving the furnace, reducing the energy consumption required for external cooling. The gradually decreasing temperature helps to maintain the structural integrity of the pyrolyzed material, especially for fragile components such as glass panels and battery silicon wafers, to prevent them from breaking or being damaged due to sudden cooling. The material integrity makes subsequent physical sorting (such as screening, liquid medium separation and air flow separation) easier to carry out, improving the recovery rate and purity of various materials.

[0057] In summary, the temperature distribution strategy of rising first and then falling along the multilayer board conveying path can minimize the generation of harmful substances such as fluoride while ensuring effective pyrolysis, and improve energy utilization efficiency as well as the quality and reuse rate of recycled materials. It embodies the principles of environmental friendliness and resource conservation, and is of great significance for promoting the efficient recycling of waste photovoltaic modules.

[0058] Fourth embodiment:

[0059] Based on any of the above embodiments, the temperature distribution in the pyrolysis tunnel furnace in the above S600 is: gradually increasing along the multilayer board conveying path.

[0060] The gradually increasing temperature distribution along the conveying path allows the EVA pyrolysis residue to have a gradual temperature increase process before entering the higher temperature area, which helps to uniform the temperature inside the material, reduce the thermal stress caused by excessive temperature gradient, and avoid material rupture or structural damage; because the temperature is gradually increased, the low-temperature area at the front end can absorb the heat from the high-temperature area at the rear end, achieve a certain degree of heat recycling, and reduce overall energy consumption; the stable and controllable heating process helps to produce relatively pure gaseous products, such as olefin mixtures, which can be used as chemical raw materials or fuels and have high economic value.

[0061] In addition, the generated pyrolysis gas can be used to heat the materials at the front end to further improve the energy efficiency of the system.

[0062] Fifth embodiment:

[0063] Based on any of the above embodiments, the time for the multilayer board to pass through the pyrolysis tunnel furnace is 15 to 70 minutes.

[0064] The time range of 15 to 70 minutes is sufficient for the multilayer board to undergo sufficient pyrolysis reaction in different temperature ranges. In the S200 stage (200-380°C), it can ensure that EVA and other organic binders have enough time to decompose into gas and solid residues without incomplete pyrolysis due to too short a residence time. In the S600 stage (500-600°C), a residence time of 15 to 70 minutes allows the mixed EVA pyrolysis residue to undergo a gradual heating process from low temperature to high temperature, which helps to achieve uniform temperature distribution, promote more complete decomposition reactions, and reduce material stress caused by sudden temperature changes.

[0065] Sixth embodiment:

[0066] Based on any of the above embodiments, the battery silicon wafer particles are immersed in an alkaline solution to remove the aluminum electrode;

[0067] The battery silicon wafer particles from which the aluminum electrode and the silver electrode have been removed are immersed in an acid solution to remove the silver electrode and the anti-reflection layer.

[0068] In a specific embodiment, the alkaline solution is sodium hydroxide solution or potassium hydroxide solution; the acidic solution is any one of nitric acid, hydrochloric acid, phosphoric acid and hydrofluoric acid solution.

[0069] The above-mentioned aluminum electrode will react with alkali in an alkaline environment to form a soluble aluminum salt, which can be effectively removed. Commonly used alkaline solutions include sodium hydroxide (NaOH) or potassium hydroxide (KOH), which can selectively dissolve aluminum without significantly affecting the silicon wafer itself. After removing the aluminum electrode, the battery silicon wafer particles are immersed in an acidic solution to remove the silver electrode and the anti-reflective coating on the surface. Commonly used acidic solutions may include nitric acid (HNO3), hydrochloric acid (HCl), etc., which can effectively dissolve silver and destroy the anti-reflective layer. After the above-mentioned chemical treatment, the metal electrodes and other non-silicon components on the surface of the battery silicon wafer particles are effectively removed, which greatly improves the purity of the silicon wafer, so that the recycled silicon wafer can be more directly applied to new photovoltaic products or other semiconductor manufacturing fields.

[0070] Seventh embodiment:

[0071] Based on any of the above embodiments, the pyrolysis gas is condensed to obtain a mixed gas and an acetic acid solution; wherein the mixed gas includes carbon dioxide and argon.

[0072] Condensing the pyrolysis gas not only helps to separate and recover valuable chemicals, but also reduces greenhouse gases and other harmful substances emitted into the atmosphere. The pyrolysis gas produced during the pyrolysis process contains a variety of volatile organic compounds, water vapor, and some non-condensable gases such as carbon dioxide (CO2) and argon (Ar). The pyrolysis gas is cooled to an appropriate temperature through a condensing device to condense the volatile organic compounds and water therein. Valuable chemicals (such as acetic acid, which is an important substance in the chemical and energy industries) can be recovered through effective treatment of the pyrolysis gas.

[0073] The above-mentioned mixed gas is mainly composed of carbon dioxide and argon. Carbon dioxide can be considered to use carbon capture and storage technology to reduce its impact on climate change; argon has a wide range of industrial applications, such as welding, metal processing and other fields. Therefore, separating and recovering argon from the mixed gas has certain economic value; the acetic acid solution formed by condensing the pyrolysis gas can be further purified to obtain high-purity acetic acid, which is an important chemical raw material that can be used to produce a variety of products such as cellulose acetate and plastic plasticizers.

[0074] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for pyrolysis recovery of waste photovoltaic modules, characterized in that: The following steps are involved: S100, pre-disassembling the discarded photovoltaic modules to obtain aluminum frames, junction boxes and multilayer panels; S200, transporting the multilayer board to a pyrolysis tunnel furnace to obtain pyrolysis gas and pyrolysis multilayer board; wherein the temperature inside the pyrolysis tunnel furnace is controlled at 200-380°C; S300, classifying the pyrolysis multilayer boards to obtain complete pyrolysis boards and fragmented pyrolysis boards; S400, disassembling the complete pyrolysis plate to obtain a first EVA pyrolysis residue, a complete glass plate, a complete battery silicon wafer and a complete back plate; S500, cutting the fragmented pyrolysis plate to obtain pyrolysis particles; The pyrolysis particles are sorted to obtain second EVA pyrolysis residue, glass particles, battery silicon wafer particles and backplane particles; S600, mixing the first EVA pyrolysis residue and the second EVA pyrolysis residue to obtain a mixed pyrolysis residue; conveying the mixed pyrolysis residue to a pyrolysis tunnel furnace to obtain an olefin mixture and a third pyrolysis residue; wherein the temperature in the pyrolysis tunnel furnace is controlled at 500-600°C.

2. The pyrolysis recovery method according to claim 1, characterized in that: The specific steps of sorting the pyrolysis particles in S500 include: S510, screening the pyrolysis particles by a screening device to obtain a second EVA pyrolysis residue and first particles to be separated; S520, separating the first particles to be separated by a liquid medium to obtain backplane particles and second particles to be separated; S530, separating the second particles to be separated by airflow to obtain glass particles and battery silicon wafer particles.

3. The pyrolysis recovery method according to claim 1, characterized in that: The temperature distribution in the pyrolysis tunnel furnace in S200 is as follows: it first rises and then falls along the multilayer board conveying path.

4. The pyrolysis recovery method according to claim 1, characterized in that: The temperature distribution in the pyrolysis tunnel furnace in S600 is as follows: the temperature gradually increases along the multilayer board conveying path.

5. The pyrolysis recovery method according to claim 1, characterized in that: The time for the multilayer board to pass through the pyrolysis tunnel furnace is 15 to 70 minutes.

6. The pyrolysis recovery method according to claim 2, characterized in that: Immersing the battery silicon wafer particles in an alkaline solution to remove the aluminum electrode; The battery silicon wafer particles from which the aluminum electrode and the silver electrode have been removed are immersed in an acidic solution to remove the silver electrode and the anti-reflection layer.

7. The pyrolysis recovery method according to claim 6, characterized in that: The alkaline solution is sodium hydroxide solution or potassium hydroxide solution; the acidic solution is any one of nitric acid, hydrochloric acid, phosphoric acid and hydrofluoric acid solution.

8. The pyrolysis recovery method according to claim 1, characterized in that: The pyrolysis gas is condensed to obtain a mixed gas and an acetic acid solution; wherein the mixed gas includes carbon dioxide and argon.

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