Recycling method of photovoltaic module

Abstract

The invention discloses a photovoltaic module recovery method. The method comprises the following steps: dismounting a junction box and a frame of a photovoltaic module, sorting and heating components with undamaged glass cover plates, separating the glass cover plates, and carrying out crushing, anaerobic thermal cracking and product post-treatment on the dismounted components. According to the invention, the process of identifying and sorting according to the damage condition of the glass cover plate is added in the recovery process of the photovoltaic module, so that the disassembly efficiency is improved, and the existing process is simplified; carbon elements in the organic matters after thermal cracking are converted into carbon black, and the carbon black can be reused as an important raw material in the rubber industry; the cracking temperature of the athermal oxygen cracking reaction is 200-300 DEG C lower than the aerobic cracking temperature, so that energy can be saved; the anaerobic thermal cracking process improves the recovery rate and recovery purity of various elements.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and in particular to a method for recycling photovoltaic components. Background Art

[0002] Photovoltaic power generation has become one of the important ways for countries to achieve their climate goals, and installed capacity has grown rapidly.

[0003] However, the large-scale application of photovoltaic power generation inevitably leads to the recycling of discarded photovoltaic modules, which needs to be solved urgently. Summary of the invention

[0004] At present, photovoltaic module recycling technology has been initially formed at home and abroad, but high recycling costs, low efficiency, and secondary pollution to the environment are still problems that the recycling industry needs to face. The technical difficulties in solving the problems are still focused on improving the efficiency of module disassembly and the recovery rate of each component while taking into account green and environmental protection characteristics.

[0005] The present application provides a photovoltaic module recycling method, comprising the following steps:

[0006] Step 1: Remove the junction box and frame from the photovoltaic module;

[0007] Step 2: sorting out photovoltaic modules with undamaged glass cover plates;

[0008] Step 3: Heating the photovoltaic module with undamaged glass cover;

[0009] Step 4: Separate the photovoltaic module with an intact glass cover into the glass cover and disassembled components;

[0010] Step 5: Break and disassemble the parts;

[0011] Step 6: Disassembled parts after anaerobic thermal cracking and crushing;

[0012] Step 7: Post-treating the products after anaerobic pyrolysis, the products include pyrolysis gas and solid residue.

[0013] Furthermore, step 1, step 2, step 3, and step 4 are performed continuously in sequence.

[0014] Furthermore, in step 1, a visual appearance detection system is used to locate the junction box and the frame, and the visual appearance detection system includes image input, image analysis and judgment output modules.

[0015] Furthermore, in step 2, a visual appearance inspection system is used to inspect and sort the damage of the glass cover plate, and the visual appearance inspection system includes image input, image analysis and judgment output modules.

[0016] Furthermore, the heating in step 3 is tunnel circulating hot air heating, the temperature range is 120°C to 180°C, and the constant temperature time is 30 seconds to 180 seconds.

[0017] Furthermore, the heating in step 3 is tunnel circulating hot air heating, the temperature range is 150°C to 180°C, and the constant temperature time is 30 seconds to 60 seconds.

[0018] Furthermore, the separation in step 4 is mechanical separation, including one or more of shearing, cutting, peeling, friction and the like.

[0019] Furthermore, the crushing in step 5 includes one or more of stirring, shearing, grinding, and freeze-drying.

[0020] Furthermore, the oxygen-free thermal cracking in step 6 is carried out in a thermal cracking furnace, and the temperature range of the thermal cracking furnace is 300°C to 500°C.

[0021] Furthermore, step 7 includes cooling, spray cleaning, recycling or using the pyrolysis gas.

[0022] Furthermore, the condensed liquid obtained after cooling the pyrolysis gas is used as fuel.

[0023] Furthermore, the pyrolysis gas is cooled and then spray-cleaned to obtain small molecule gas, which is used as combustible gas.

[0024] Furthermore, step 7 includes cooling and sorting the solid residue, and the sorting is performed by vibration, air separation, electromagnetic field, etc.

[0025] The advancement of the present application over the prior art lies in: 1) In the process of recycling photovoltaic modules, a process of identifying and sorting according to the damage of the glass cover is added, and the modules are classified according to the results of visual appearance inspection, thereby improving the disassembly efficiency; 2) The intact modules of the glass cover are disassembled, and the intact glass cover is disassembled by heating first and then separating, and the disassembly parts after anaerobic thermal cracking and product post-processing are performed, thereby simplifying the existing process; 3) After thermal cracking, the carbon element in the organic matter is converted into carbon black, which can be reused as an important raw material for the rubber industry; the cracking temperature of the thermal oxygen-free cracking reaction is 200 to 300°C lower than the aerobic cracking temperature, which is conducive to saving energy; the anaerobic thermal cracking process improves the recovery rate and recovery purity of various elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart of the component recycling method. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation modes.

[0028] The "photovoltaic module" referred to in this application refers to a photovoltaic single-sided or double-sided glass module, which is composed of a backplane (glass cover), packaging materials, silicon battery elements, packaging materials and glass cover stacked in sequence.

[0029] The "glass cover intact component" referred to in this application refers to the photovoltaic component after the junction box and frame are removed, and the glass cover is not damaged. It consists of silicon battery elements, backplane (glass cover), packaging materials and glass cover.

[0030] The "disassembled parts" referred to in this application refer to the parts after the glass cover plate is removed from the intact components of the glass cover plate, which are composed of silicon battery elements, backplanes, and packaging materials, and contain a small amount of glass residue.

[0031] The silicon battery element is composed of silicon battery cells, grid lines, welding strips, and bus bars, and contains crystalline / amorphous silicon, silver, copper, aluminum, tin and other elements. The backplane is generally composed of a fluorine-containing polymer coating, a polymer substrate, and an adhesive layer, and contains carbon, hydrogen, oxygen, fluorine and other elements. The packaging material is composed of high molecular polymers. Commonly used high molecular polymer pairs can be EVA, POE, PVB, silicone, etc., containing carbon, hydrogen, oxygen, silicon and other elements.

[0032] Figure 1 The process of recycling photovoltaic modules of this application is shown.

[0033] The photovoltaic module recycling method of the present application comprises the following steps in order: after removing the frame and junction box of the photovoltaic module, visual appearance inspection is performed on the remaining parts of the photovoltaic module, and the glass cover plate intact components are sorted out, and the glass cover plate damaged components can be processed in other ways; the glass cover plate intact components obtained by the above sorting are heated, the main purpose of which is to soften the packaging material so that the packaging material and the glass cover plate can be better separated under the action of mechanical force; the separated glass cover plate intact components are divided into two parts: the glass cover plate and the disassembled parts, the disassembled parts are crushed to obtain fragments or particles, the crushed disassembled parts are thermally cracked, and the products are separated after the thermal cracking.

[0034] In some embodiments, the frame and junction box around the assembly can be removed manually or mechanically.

[0035] In some embodiments, a visualization system may be used to identify the junction box and the frame, and after successful identification, an automated blade or fixture may be used to remove the junction box on the back of the component.

[0036] In some embodiments, an automatic frame removal machine may be used to increase the outward expansion force of the frame of the photovoltaic module and completely remove the frame.

[0037] In some embodiments, the mechanical device for removing the junction box and the frame in the assembly includes a fixing device, a scraper and a driving device. The assembly is first fixed, and then the driving device drives the scraper to remove the junction box and the frame.

[0038] In some embodiments, an online visualization system is used to sort the intact components of the glass cover plate, and the online visualization system includes image input, image analysis and judgment output modules. The components with the junction box and frame removed are transported to the inspection table by a conveying device, and the appearance of the components is photographed in real time by a camera device, and the obtained images are analyzed by software, and the images are judged according to the damage area judgment requirements preset by the software, and the intact components and damaged components are sorted according to the judgment results.

[0039] In some embodiments, the glass cover plate intact component passes through a tunnel circulating hot air heating furnace, the temperature of the heating furnace is set at a constant temperature between 120°C and 180°C, and the glass cover plate intact component is conveyed by a conveyor belt through the tunnel circulating hot air heating furnace to complete heat exchange, and the passing time is 30 seconds to 180 seconds. Heating is conducive to the separation of the packaging material and the glass. In the case of a low heating temperature, the effect of facilitating the separation of the packaging material and the glass can be achieved by extending the heat exchange time.

[0040] In some embodiments, the separation method of the glass cover is mechanical separation, including shearing, cutting, peeling, rubbing, etc. The mechanical separation methods can be used alone or in combination, such as first peeling the packaging material and then rubbing the residual polymer on the glass cover, or first cutting the packaging material and then rubbing the residual polymer on the glass cover. The above separation can be performed at room temperature or at high temperature, such as cutting with a hot cutter or directly cutting at a constant temperature.

[0041] In some embodiments, the disassembled photovoltaic modules are transferred by a transmission and transportation device to achieve continuous operation. The transmission and transportation device can be a belt drive, a roller drive, or a chain drive.

[0042] In some embodiments, the crushing method of the disassembled parts includes stirring, shearing, grinding, and freeze drying, which can be used alone or in combination, such as grinding under low temperature conditions. After the disassembled parts are crushed, various materials are initially separated, such as tin-coated solder strips, bus bars, and granular disassembled parts.

[0043] In some embodiments, the anaerobic pyrolysis temperature is 300°C to 500°C, and an appropriate amount of pyrolysis catalyst may be added. Under low temperature conditions, the pyrolysis reaction time may be extended. During the pyrolysis process, organic matter undergoes changes such as gasification or cracking under high temperature conditions, and the gasified or cracked gas is cooled and collected. In addition to partial gasification, the organic matter is also partially carbonized and remains in the solid residue for further recovery and sorting.

[0044] In some embodiments, the solid residue can be ground again, and electrostatic separation, vibration separation, air separation, etc. can be used to obtain carbon black powder, metal powder, and silicon powder of different particle sizes.

Claims

1. A photovoltaic module recycling method, characterized in that: The following steps are involved: Step 1: Remove the junction box and frame from the photovoltaic module; Step 2: sorting out photovoltaic modules with undamaged glass cover plates; Step 3: heating the photovoltaic module without damage to the glass cover; Step 4: Separating the photovoltaic module with an intact glass cover into a glass cover and disassembled components; Step 5: crushing the disassembled parts; Step 6: anaerobic thermal cracking and crushing of the disassembled parts; Step 7: Post-treating the product after the anaerobic pyrolysis, wherein the product includes pyrolysis gas and solid residue.

2. The photovoltaic module recycling method according to claim 1, characterized in that: The step 1, the step 2, the step 3 and the step 4 are performed successively.

3. The photovoltaic module recycling method according to claim 1, characterized in that: In the step 1, a visual appearance detection system is used to locate the junction box or the frame, and the visual appearance detection system includes image input, image analysis and determination output modules.

4. The photovoltaic module recycling method according to claim 1, characterized in that: In the step 2, a visual appearance inspection system is used to inspect and sort the damage of the glass cover plate, and the visual appearance inspection system includes image input, image analysis and judgment output modules.

5. The photovoltaic module recycling method according to claim 1, characterized in that: The heating in step 3 is tunnel circulating hot air heating, the temperature range is 120° C. to 180° C., and the constant temperature time is 30 seconds to 180 seconds.

6. The photovoltaic module recycling method according to claim 1, characterized in that: The heating in step 3 is tunnel circulating hot air heating, the temperature range is 150° C. to 180° C., and the constant temperature time is 30 seconds to 60 seconds.

7. The photovoltaic module recycling method according to claim 1, characterized in that: The separation in step 4 is mechanical separation, including one or more of shearing, cutting, peeling, friction and the like.

8. The photovoltaic module recycling method according to claim 1, characterized in that: The crushing in step 5 includes one or more of stirring, shearing, grinding, and freeze drying.

9. The photovoltaic module recycling method according to claim 1, characterized in that: The oxygen-free thermal cracking in step 6 is carried out in a thermal cracking furnace, and the temperature range of the thermal cracking furnace is 300°C to 500°C.

10. The photovoltaic module recycling method according to claim 1, characterized in that: The step 7 includes cooling, spray cleaning, recycling or using the pyrolysis gas.

11. The photovoltaic module recycling method according to claim 1 or 10, characterized in that: The condensed liquid obtained by cooling the pyrolysis gas is used as fuel.

12. The photovoltaic module recycling method according to claim 1 or 10, characterized in that: After the pyrolysis gas is cooled, the spray cleaning is performed to obtain small molecule gas, and the small molecule gas is used as combustible gas.

13. The method for recycling disassembled parts of photovoltaic modules according to claim 1, characterized in that: The step 7 includes cooling and sorting the solid residue, and the sorting is performed by vibration, air separation, electromagnetic field, etc.

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