Recovery device for improving recovery value of EVA (Ethylene Vinyl Acetate) in waste photovoltaic module
By designing a recycling device that includes pyrolysis, catalytic cracking, and combustion heating units, the problem of separating EVA film from backsheet was solved, achieving efficient EVA resource recycling, reducing energy consumption, and increasing recycling value.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XINYANG NORMAL UNIVERSITY
- Filing Date
- 2025-05-08
- Publication Date
- 2026-04-28
AI Technical Summary
In existing technologies, it is difficult to efficiently separate the EVA film from the backsheet of waste photovoltaic modules, resulting in resource waste and low recycling value, insufficient utilization of tar, high energy consumption in the pyrolysis process, and low resource recycling efficiency.
Design a recycling device including a pyrolysis unit, a catalytic cracking unit, a cooling and collection unit, and a combustion heating unit. The device uses a catalyst bed to catalytically crack the large molecular alkanes and olefins produced by the pyrolysis of EVA into short-chain alkanes and olefins, and uses a combustion furnace to provide energy, thereby reducing energy consumption and improving the value of resource utilization.
This has enabled high-value recycling of EVA, reduced energy consumption in catalytic cracking, improved resource recycling efficiency, avoided resource waste, and promoted the development of the waste photovoltaic module recycling industry.
Smart Images
Figure CN224168326U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of resource recycling technology, specifically relating to a recycling device for improving the recycling value of EVA in waste photovoltaic modules. Background Technology
[0002] Achieving green and high-value recycling of waste crystalline silicon photovoltaic modules is crucial for realizing resource recycling. The processing of the encapsulating film (EVA) and backsheet is a core issue in the recycling of waste photovoltaic modules. Several processing methods exist: one involves direct incineration in the air, which causes severe air and soil pollution; another involves crushing the modules, resulting in the EVA film and backsheet becoming mixed together, difficult to separate, and with low overall metal separation efficiency, leading to resource waste. Since the backsheet contains a large amount of fluorine, pyrolysis releases fluorine-containing gases, requiring expensive exhaust gas treatment and failing to generate high recycling value. Another method avoids crushing, first separating the backsheet and EVA film, then pyrolyzing the EVA film, solar cells, and solder ribbons together. The challenge of this method lies in the efficient separation of the backsheet and EVA.
[0003] The separated EVA-encapsulated solar cells and solder ribbons can be directly pyrolyzed. In addition, for double-glass crystalline silicon photovoltaic modules, the encapsulation material is EVA, which can also be directly pyrolyzed. Pyrolysis produces gases and tar. The pyrolysis gases contain low-carbon gases such as methane, ethane, and ethylene, while the tar usually contains large-molecule alkanes and alkenes, with a carbon content of up to 15 or more. Currently, there is a lack of effective utilization of this type of tar in industrialization or scientific research, which has not achieved high economic value in resource recycling and is not conducive to the development of the waste photovoltaic module recycling industry. Utility Model Content
[0004] To address the above issues and overcome the shortcomings of existing technologies, this invention provides a recycling device for increasing the recycling value of EVA in waste photovoltaic modules. This device can catalytically crack the large-molecule long-chain alkanes or olefins produced by EVA pyrolysis into short-chain alkanes and olefins. After cooling, these produce high-value gasoline or kerosene, thus increasing the economic value of EVA recycling. Simultaneously, by combining catalytic cracking with pyrolysis, the high-temperature tar molecules produced by pyrolysis can be directly catalytically cracked, reducing the energy consumption required for catalytic cracking. Furthermore, the gases produced by pyrolysis and catalytic cracking are cooled and then enter the combustion furnace to provide energy for the system, further enhancing the utilization value.
[0005] A recycling device for improving the recycling value of EVA in waste photovoltaic modules includes a pyrolysis unit, a catalytic cracking unit, a cooling and collection unit, and a combustion and heating unit connected in sequence. The pyrolysis unit includes a pyrolysis furnace equipped with an inlet pipe, a solid emission pipe, and a nitrogen pipe. The catalytic cracking unit is located at the top of the pyrolysis furnace and is connected to the gas outlet of the pyrolysis furnace. The catalytic cracking unit includes a reaction tower, the inlet of which is directly connected to the gas outlet of the pyrolysis furnace. The cooling and collection unit includes an oil collection tank and a condensation structure located outside the oil collection tank. The gas inlet of the oil collection tank is connected to the gas outlet of the catalytic cracking unit for condensing the cracked gas into liquid hydrocarbons. The combustion and heating unit includes a combustion furnace, the inlet of which is connected to the gas outlet of the cooling and collection unit. The top of the combustion furnace is connected to a heating pipe that provides heat to the pyrolysis furnace and the catalytic cracking furnace through the pipe.
[0006] Preferably, the reaction tower is provided with a catalyst bed, which is composed of zeolite, alumina and silica.
[0007] Preferably, the outer wall of the reaction tower is provided with a heat insulation layer, and the heat insulation layer can be connected to the combustion furnace through a heating pipe, and the combustion furnace provides heat to the reaction tower.
[0008] Preferably, the condensation structure is a spiral condenser tube arranged around the outer wall of the oil receiving tank, the spiral condenser tube is connected to an external cooling medium circulation system, and a drain pipe for discharging liquid is fixedly connected to the bottom of the side of the oil receiving tank.
[0009] Preferably, the bottom of the side of the combustion furnace is provided with a natural gas pipeline for filling the furnace with natural gas and an air pipeline to ensure air circulation.
[0010] Preferably, the solid discharge pipe and gas outlet of the pyrolysis furnace, the inlet and gas outlet of the reaction tower, the gas inlet and liquid discharge pipe of the oil receiving tank, and both ends of the heating pipeline are equipped with solenoid valves to control the flow.
[0011] The beneficial effects of the above technical solution are as follows:
[0012] This recycling device, designed to enhance the recycling value of EVA from waste photovoltaic modules, catalytically cracks the large-molecule long-chain alkanes or olefins produced by EVA pyrolysis into short-chain alkanes and olefins. After cooling, these produce high-value gasoline or kerosene, increasing the economic value of EVA recycling. Simultaneously, by combining catalytic cracking with pyrolysis, the high-temperature tar molecules produced by pyrolysis can be directly subjected to catalytic cracking, reducing the energy consumption required for catalytic cracking. Furthermore, the gases produced by pyrolysis and catalytic cracking are cooled and then fed into a combustion furnace, providing energy to sustain the system and enhancing its utilization value. This achieves high-value recycling of waste EVA, avoids resource waste, and promotes the development of the waste photovoltaic module recycling industry. Attached Figure Description
[0013] Fig. 1 This is a schematic diagram of the overall structure of this utility model;
[0014] Fig. 2 This is a schematic diagram of the disassembled state of this utility model;
[0015] Fig. 3 This is a schematic cross-sectional view of the reaction tower of this utility model.
[0016] In the diagram: 1. Pyrolysis furnace; 101. Sample inlet pipe; 102. Solid discharge pipe; 103. Nitrogen pipe; 2. Reaction tower; 3. Oil collection tank; 4. Combustion furnace; 401. Heating pipeline; 5. Catalyst bed; 6. Insulation layer; 7. Spiral condenser; 8. Drain pipe; 9. Natural gas pipeline; 10. Air pipeline; 11. Solenoid valve. Detailed Implementation
[0017] The foregoing and other technical contents, features and effects of this utility model are described in conjunction with the appendix below. Figs. 1 to 3 The embodiments are described in detail below.
[0018] This embodiment provides a recycling device for increasing the recycling value of EVA in waste photovoltaic modules, as shown in the attached diagram. Figs. 1-3 As shown, the system includes a pyrolysis unit, a catalytic cracking unit, a cooling and collection unit, and a combustion and heating unit connected in sequence. The pyrolysis unit includes a pyrolysis furnace 1 equipped with an inlet pipe 101, a solid discharge pipe 102, and a nitrogen pipe 103. Silicon wafers and solder ribbons wrapped in EVA can be added into the pyrolysis furnace 1 through the inlet pipe 101, and nitrogen can be introduced into the pyrolysis furnace 1 through the nitrogen pipe 103 to perform anaerobic pyrolysis on the EVA-wrapped silicon wafers and solder ribbons, generating tar gas (containing macromolecular hydrocarbons), low-carbon gas (methane, ethane, etc.), and solid residues (silicon powder, solder ribbons). The solid residues are discharged through the bottom solid discharge pipe 102, and the gas enters the catalytic cracking unit through the top outlet pipe.
[0019] The catalytic cracking unit is located at the top of the pyrolysis furnace 1 and connected to the gas outlet of the pyrolysis furnace. The catalytic cracking unit includes a reaction tower 2, the inlet of which is directly connected to the gas outlet of the pyrolysis furnace 1. In the chemical industry, reaction towers (or reactors) are common industrial equipment, such as fixed-bed reactors and fluidized-bed reactors in petrochemicals, used for gas-solid or gas-liquid phase catalytic reactions. This is a well-known technology and will not be elaborated on here. The reaction tower 2 is equipped with a catalyst bed 5, which is composed of zeolite, alumina, and silica. The filling height accounts for 2 / 3 of the reaction tower volume. 3. The outer wall of the reaction tower 2 is provided with a heat insulation layer 6, which can be connected to the heating pipe 401 through a pipe to introduce the heat of the combustion furnace 4 into the reaction tower 2. The heat insulation layer 6 can be made of ceramic fiber material, which wraps the outer wall of the reaction tower 2 to form a heat insulation cavity between the heat insulation layer 6 and the reaction tower 2, reducing heat loss. The reaction tower 2 can receive high-temperature tar gas (500-550℃) from the pyrolysis unit. Under the action of the catalyst, it can crack large carbon chain molecules (including large molecular alkanes and alkenes) into broken chain molecules. The cracked gas enters the cooling and collection unit through the top outlet of the reaction tower 2.
[0020] The cooling and collection unit includes an oil collection tank 3 and a condensing structure located outside the oil collection tank. The condensing structure consists of a spiral condensing pipe 7 surrounding the outer wall of the oil collection tank 3. The spiral condensing pipe 7 is connected to an external cooling medium circulation system (such as a water-cooled unit). A drain pipe 8 for discharging liquid is fixedly connected to the bottom of the side of the oil collection tank 3. After the cracked gas enters the oil collection tank 3, it is cooled by the spiral condensing pipe 7, causing the low-carbon chain hydrocarbon gas to condense into a liquid state, fall to the bottom of the tank, and be collected through the drain pipe 8. Uncondensed low-carbon gases (such as methane and ethane) are transported to the combustion and heating unit from the top outlet.
[0021] The inlet of the oil collection tank 3 is connected to the gas outlet of the catalytic cracking unit, which is used to condense the cracked gas into liquid hydrocarbons. The combustion heating unit includes a combustion furnace 4, whose inlet is connected to the gas outlet of the cooling collection unit. The top of the combustion furnace 4 is connected to a heating pipe 401 and is connected to the pyrolysis furnace 1 through the heating pipe 401. The bottom of the side of the combustion furnace 4 is provided with a natural gas pipe 9 for filling natural gas into it and an air pipe 10 to ensure air circulation. The uncondensed low-carbon gas is mixed with natural gas and burned directly in the combustion furnace 4 to produce high-temperature flue gas. The flue gas supplies heat to the pyrolysis furnace 1 and the reaction tower 2 through the heating pipe 401 to maintain the operation of the pyrolysis furnace and the reaction tower.
[0022] The remaining waste heat can be utilized for purposes such as heating the factory area, cleaning processes, or heating hot water.
[0023] The solid discharge pipe 102 and gas outlet of pyrolysis furnace 1, the inlet and gas outlet of reaction tower 2, the gas inlet and liquid discharge pipe 8 of oil collection tank 3, and both ends of heating pipeline 401 are equipped with solenoid valves 11 to control the flow. The solenoid valves 11 in each part can be controlled by an external control unit to control the opening and closing of the overall pipeline in the device, ensuring the stable operation of each process. Pyrolysis furnace 1, reaction tower 2, oil collection tank 3, combustion furnace 4 and solenoid valves 11 are all connected to the external control unit by wires, and pyrolysis furnace 1, reaction tower 2, oil collection tank 3 and combustion furnace 4 can all be fixed to the ground by mounting brackets.
[0024] In summary, the recycling device for increasing the recycling value of EVA in waste photovoltaic modules has the following operating steps:
[0025] 1. The separated EVA material (encapsulating silicon wafers and solder ribbons) is sent into the pyrolysis furnace 1 through the injection tube 101. The nitrogen supply system is started to ensure that the furnace is an oxygen-free environment, and then the injection tube 101 is sealed.
[0026] 2. The heating system raises the furnace temperature to 500-550℃. EVA pyrolysis produces tar gas and solid residue. The solid residue (silicon powder, welding ribbon) is periodically discharged through the bottom solid discharge pipe 102, and the gas enters the reaction tower 2 through the top outlet.
[0027] 3. Tar gas comes into contact with the catalyst in reaction tower 2, and the large molecular hydrocarbons are cracked into low-carbon chain hydrocarbons. The cracked gas enters the cooling and collection unit through the outlet of reaction tower 2.
[0028] 4. The cracked gas enters the oil receiving tank 3, and cooling water (such as 20°C cold water) is introduced into the spiral condenser 7 to reduce the gas temperature in the oil receiving tank 3 to 10-20°C. The liquid hydrocarbons (gasoline / kerosene components) are deposited to the bottom of the tank and collected through the drain pipe 8.
[0029] 5. Uncondensed gases (methane, ethane, etc.) are transported from the top outlet to the combustion furnace 4. The uncondensed gases are mixed with natural gas in proportion and then burned in the combustion furnace 4. The high-temperature flue gas is supplied with heat to the pyrolysis furnace 1 and the reaction tower 2 through the heating pipe 401 to maintain the system operating temperature.
[0030] The above description is only for illustrating the present utility model. It should be understood that the present utility model is not limited to the above embodiments, and various modifications that conform to the concept of the present utility model are within the protection scope of the present utility model.
Claims
1. A recycling device for increasing the recycling value of EVA in waste photovoltaic modules, characterized in that: The system includes a pyrolysis unit, a catalytic cracking unit, a cooling and collecting unit, and a combustion and heating unit connected in sequence. The pyrolysis unit includes a pyrolysis furnace (1) equipped with an inlet pipe (101), a solid discharge pipe (102), and a nitrogen pipe (103). The catalytic cracking unit is located at the top of the pyrolysis furnace (1) and is connected to the gas outlet of the pyrolysis furnace. The catalytic cracking unit includes a reaction tower (2), the inlet of which is directly connected to the gas outlet of the pyrolysis furnace (1). The cooling and collecting unit includes an oil collection tank (3) and a condensation structure located outside the oil collection tank. The inlet of the oil collection tank (3) is connected to the gas outlet of the catalytic cracking unit and is used to condense the cracked gas into liquid hydrocarbons. The combustion and heating unit includes a combustion furnace (4), the inlet of which is connected to the gas outlet of the cooling and collecting unit. The top of the combustion furnace (4) is connected to a heating pipe (401) and provides heat to the pyrolysis furnace (1) and the reaction tower (2) through the heating pipe (401).
2. The recycling device for improving the recycling value of EVA in waste photovoltaic modules according to claim 1, characterized in that: The reaction tower (2) is equipped with a catalyst bed (5) inside, which is composed of zeolite, alumina and silica.
3. A recycling device for improving the recycling value of EVA in waste photovoltaic modules according to claim 1, characterized in that: The outer wall of the reaction tower (2) is provided with a heat insulation layer (6), and the heat insulation layer (6) can be connected to the heating pipe (401) through a pipe. The heating pipe is used to heat the reaction tower (2).
4. A recycling device for improving the recycling value of EVA in waste photovoltaic modules according to claim 1, characterized in that: The condensation structure is a spiral condenser tube (7) arranged around the outer wall of the oil receiving tank (3). The spiral condenser tube (7) is connected to the external cooling medium circulation system. A drain pipe (8) for discharging liquid is fixedly connected to the bottom of the side of the oil receiving tank (3).
5. A recycling device for improving the recycling value of EVA in waste photovoltaic modules according to claim 1, characterized in that: The bottom side of the combustion furnace (4) is provided with a natural gas pipe (9) for filling natural gas into it and an air pipe (10) for ensuring air circulation.
6. A recycling device for improving the recycling value of EVA in waste photovoltaic modules according to claim 1, characterized in that: The solid discharge pipe (102) and gas outlet of the pyrolysis furnace (1), the inlet and gas outlet of the reaction tower (2), the gas inlet and liquid discharge pipe (8) of the oil collection tank (3), and both ends of the heating pipeline (401) are equipped with solenoid valves (11) to control the flow.