Recycling method for disassembled parts of photovoltaic module

Abstract

The invention discloses a recovery method of a photovoltaic module disassembly part, which is characterized in that the disassembly part formed by a battery part, a glue film and a back plate generated in the photovoltaic module recovery process is subjected to cracking separation, and the cracking separation process comprises feeding, anaerobic thermal cracking, pyrolysis gas post-treatment and solid residue post-treatment. Compared with the prior art, the method has the advantages that cracking separation is carried out in an oxygen-free mode, and obtained small-molecule gas and condensed liquid serve as a pyrolyzing furnace to assist in heating combustible gas and fuel, so that heat balance of the system is maintained; 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 anaerobic thermal cracking reaction is 200-300 DEG C lower than the aerobic cracking temperature, so that energy is 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 disassembled components of a photovoltaic module. Background Art

[0002] With the deterioration of the global environment and the increasing energy crisis, carbon peak and carbon neutrality have become a global consensus. Photovoltaic power generation has become one of the important ways for countries to achieve climate goals, and installed capacity has grown rapidly. In 2021, the world's new photovoltaic installed capacity reached 183GW, an increase of more than 30% year-on-year. It is expected that by 2030, this figure will increase to 334GW. As the country with the most mature development of the photovoltaic industry, my country's cumulative installed capacity of photovoltaic power generation has exceeded 200GW. It is estimated that by 2030, my country's annual new installed capacity will reach 105-128GW.

[0003] However, the large-scale application of photovoltaic power generation inevitably leads to the recycling of discarded photovoltaic modules. According to the International Energy Agency, by 2030, the global recycling of photovoltaic modules will reach about 8 million tons, and China will have about 1.5 million tons of photovoltaic modules to be recycled. The recycling problem of photovoltaic modules 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] Chinese patent applications 202311492664.X, 202311492658.4, 202311486234.7, and 202311486232.8 disclose methods for recycling photovoltaic modules, which achieve material recovery through on-site disassembly, separation of glass panels, thermal cracking of wrapping layers, and sorting processes. This application provides a method for processing disassembled components of optical modules, including the following steps:

[0006] Providing a disassembled component consisting of a battery portion and an organic coating layer;

[0007] anaerobic thermal cracking of the disassembled components;

[0008] obtaining a gas composition; and

[0009] A solid component was obtained.

[0010] Another object of the present invention is that in the step of performing anaerobic thermal cracking on the disassembled parts, the disassembled parts are provided in a continuous manner.

[0011] Another object of the present invention is that the gas components and solid components are obtained in a continuous manner.

[0012] Another object of the present invention is that the temperature range of the anaerobic pyrolysis is between 300 °C and 450 °C.

[0013] Another object of the present invention is that the anaerobic pyrolysis step includes four gradient temperature segments, namely a drying segment, a degradation segment, a gasification segment, and a pyrolysis segment. The temperature range of the drying segment is between 80 °C and 100 °C, the temperature range of the degradation segment is between 130 °C and 250 °C, the temperature range of the gasification segment is between 260 °C and 350 °C, and the temperature range of the pyrolysis segment is between 300 °C and 430 °C.

[0014] Another object of the present invention is that the anaerobic pyrolysis is indirectly heated.

[0015] Another object of the present invention is that in the step of anaerobic pyrolysis of the disassembly part, nitrogen is also introduced and a negative pressure is maintained, and the vacuum degree is maintained in the range of 0 Pa to 500 Pa.

[0016] Another object of the present invention is that before the step of anaerobic pyrolysis of the disassembly part, the disassembly part is also cut, and the maximum side length after cutting the disassembly part is less than 5 cm.

[0017] Another object of the present invention is to cool the gas components to obtain a liquid component or to spray and wash to obtain small molecule gases.

[0018] Another object of the present invention is to also cool the solid components.

[0019] Another object of the present invention is to also sort the solid components, and the sorting is carried out by a single method such as vibration, air separation, or electromagnetic field, or a mixed method.

[0020] Another object of the present invention is that the disassembly part further includes a backplane.

[0021] Another object of the present invention is that the battery part includes one, part, or all of a silicon chip, grid lines, solder tapes, and bus bars. Brief Description of the Drawings

[0022] Figure 1 It is a flow chart of the method for recycling the disassembly part of the photovoltaic module of the present invention. Detailed Description of the Invention

[0023] The following further describes the present invention in detail in conjunction with the attached Figure 1 and specific embodiments.

[0024] First, the junction box and frame of the scrapped photovoltaic module are removed, and the glass is removed to obtain the photovoltaic module disassembled parts, which are mainly composed of the battery part, the organic coating layer and a small amount of glass residue. Of course, in a certain embodiment, the disassembled parts can also be composed of the battery part, the organic coating layer, a small amount of glass residue and the back plate.

[0025] The battery part can be composed of a part, some or all of the silicon chip, grid line, welding belt, bus bar, including crystalline / amorphous silicon, silver, copper, aluminum, tin and other elements. The backplane is generally composed of fluorine-containing polymer coating, polymer substrate, adhesive layer, including carbon, hydrogen, oxygen, fluorine and other elements. The organic coating layer 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. Therefore, the organic coating layer in the disassembled part can include one or all of the film and sealant.

[0026] In some embodiments, in order to achieve continuous anaerobic pyrolysis, a thermal cracking furnace is used to perform the anaerobic pyrolysis step. Before performing anaerobic pyrolysis, the disassembled components of the photovoltaic modules need to be crushed to facilitate weighing and metering. At the same time, the production capacity can be adjusted in accordance with the space of the thermal cracking furnace. At the same time, small-sized particles are conducive to heat transfer and improve pyrolysis efficiency. Preferably, the maximum side length of the photovoltaic module disassembled components after cutting is less than 5 cm. The crushed disassembled component particles are transported into the thermal cracking furnace through a conveyor belt, and the conveyor belt maintains a uniform speed of transportation. The disassembled component particles pass through four temperature stages during the process of passing through the thermal cracking furnace: drying section, degradation section, gasification section and pyrolysis section. The residue after anaerobic pyrolysis is output from the pyrolysis furnace by the conveyor belt.

[0027] In some embodiments, the temperature of the disassembled component particles in the drying section is maintained in the range of 80°C to 100°C, at which time, the moisture in the disassembled component particles begins to evaporate; as the disassembled component particles continue to advance, the disassembled component particles enter the degradation section with a temperature range of 130-250°C, at which stage, polymers in the organic coating layer and the backplane, such as films and / or sealants, begin to melt into liquid, and small molecule organic additives in the polymer coating and the polymer begin to degrade; the disassembled component particles enter the gasification section with a temperature range of 260-350°C, and the melted polymer coating and polymer reach the decomposition temperature and gradually degrade and gasify; the disassembled component particles enter the pyrolysis section with a temperature range of 300-430°C, the disassembled component particles accelerate pyrolysis, and the organic matter that cannot be gasified completes the carbonization process.

[0028] In some embodiments, the thermal cracking furnace uses an indirectly heated rotary pyrolysis furnace, the temperature can be between 300°C and 450°C, and a temperature gradient is used to control the entire process, and the temperature is set according to the characteristics of the material pyrolysis process.

[0029] In some embodiments, the anaerobic pyrolysis process requires that the pyrolysis furnace be kept free of oxygen, and nitrogen is passed into the pyrolysis furnace and negative pressure is maintained to ensure that no oxygen or air enters the pyrolysis furnace during the anaerobic pyrolysis process, and the vacuum degree in the pyrolysis furnace is maintained between 0 Pa and 500 Pa. At the same time, due to the design of the pyrolysis furnace, the present invention can continuously feed the disassembled part formed by the battery part, the organic coating layer, and the back plate that may include the cloth.

[0030] In some embodiments, the gas components generated after anaerobic pyrolysis are post-processed and cooled by a heat exchanger, preferably a water-cooled tubular heat exchanger. Condensed liquid is generated during the cooling of the gas components, and the condensed liquid is collected and used as fuel in the anaerobic pyrolysis process.

[0031] In some embodiments of the anaerobic pyrolysis process, the gas components that cannot be liquefied after the pyrolysis gas is cooled are spray-cleaned to remove small molecular acids or salt substances soluble in water, such as hydrofluoric acid, and the gas is preferably subjected to alkaline washing after the spray-cleaning step to further remove residual hydrofluoric acid. The purified pyrolysis gas can be used as a combustible gas used in the anaerobic pyrolysis process.

[0032] In some implementation schemes of the oxygen-free pyrolysis process, solid components will be formed, and the post-processing of the solid components includes cooling and sorting processes. The solid components are preferably cooled to about 60°C for discharge. The discharged solid components are sorted, and large-sized metal strips and silicon wafers are first sorted out according to the material size, and then carbon black, silicon, and metal powders are separated by vibration, wind selection, electromagnetic field, etc. according to the different material densities. At the same time, due to the design of the pyrolysis system, the overall discharge can be continuous and uninterrupted when the gas component and the solid component are discharged.

[0033] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A method for processing disassembled parts of photovoltaic modules, It is characterized in that The following steps are involved: Providing a disassembled component consisting of a battery portion and an organic coating layer; anaerobic thermal cracking of the disassembled components; obtaining a gas composition; and A solid component was obtained.

2. The method for processing disassembled components of a photovoltaic module according to claim 1, It is characterized in that In the step of performing anaerobic thermal cracking on the disassembled parts, the disassembled parts are provided in a continuous manner.

3. The method for processing disassembled parts of a photovoltaic module according to claim 1, in, The gas component and the solid component are obtained in a continuous manner.

4. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that The temperature range of the oxygen-free thermal cracking is between 300°C and 450°C.

5. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that The anaerobic thermal cracking step includes four gradient temperature sections, namely a drying section, a degradation section, a gasification section and a pyrolysis section. The temperature range of the drying section is 80°C to 100°C, the temperature range of the degradation section is 130°C to 250°C, the temperature range of the gasification section is 260°C to 350°C, and the temperature range of the pyrolysis section is 300°C to 430°C.

6. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that The oxygen-free thermal cracking is carried out by indirect heating.

7. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that The step of anaerobic thermal cracking of the disassembly part also includes introducing nitrogen and maintaining negative pressure, and the vacuum degree is maintained in the range of 0Pa to 500Pa.

8. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that Before performing the step of anaerobic thermal cracking of the disassembling part, the disassembling part is also included in the step of cutting, and the maximum side length of the disassembling part after cutting is less than 5 centimeters.

9. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that The gas components are cooled to obtain a liquid group or spray-cleaned to obtain small molecule gases.

10. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that Also included is cooling the solid component.

11. The method for processing disassembled parts of a photovoltaic module according to claim 2, It is characterized in that It also includes sorting the solid components, wherein the sorting is performed by a single method of vibration, wind sorting or electromagnetic field, or a mixed method.

12. The method for processing disassembled parts of a photovoltaic module according to claim 1 or 2, It is characterized in that The disassembled parts also include a back panel.

13. The method for processing disassembled parts of a photovoltaic module according to claim 1 or 2, It is characterized in that The battery unit includes one, part or all of a silicon chip, a gate line, a welding strip, and a bus bar.

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