A method for recycling materials of adhesive layers in solar panel

Abstract

This invention discloses a method for recycling adhesive layer material in a solar panel, comprising the following steps: Step 1: removing a metal frame of a solar panel; Step 2: heating the solar panel using a microwave heating process, heating the upper adhesive layer material and the lower adhesive layer material of the solar panel; Step 3: separating a glass sheet of the solar panel from the wafer assembly on the solar panel, and scraping off the upper adhesive layer material on the glass sheet; and Step 4: separating a backplate of the solar panel from the wafer assembly on the solar panel, and scraping off the lower adhesive layer material on the backplate.

Description

Technical Field

[0001] This invention relates to a method for recycling solar panels, and more particularly to a method for using microwave heating to produce a recycled adhesive layer material in solar panels. Prior Technology

[0002] Solar energy is an important power generation option for the global energy transition, and therefore the installed capacity of solar energy is increasing year by year. By the end of 2024, Taiwan's installed capacity of solar energy had exceeded 14GW (million kilowatts), and it is expected to achieve the target capacity of 20GW this year. In particular, photovoltaics plays an important role in Taiwan's net-zero transition plan, with a target of 40 to 80GW of solar energy capacity by 2050.

[0003] However, solar panels have a lifespan of 20 to 30 years. According to data from the Resource Recycling Administration of the Ministry of Environment, if the lifespan of solar panels is calculated at 20 years, it is estimated that the number of waste panels will exceed 100,000 metric tons per year by 2035. In addition, about 0.5% of the waste will be generated each year due to damage caused by natural disasters. Therefore, establishing a sound recycling mechanism has become an urgent task.

[0004] Solar panels mainly consist of glass sheets, a backsheet, a metal frame, silicon crystal cells, encapsulation materials, and connecting wires. Silicon crystal cells are the core component that converts light energy into electrical energy; common types include monocrystalline and polycrystalline silicon. The glass sheets protect the cells, the metal frame provides support and fixation, and the encapsulation materials seal all components together, ensuring the solar panel's durability and airtightness. The encapsulation material that holds all components together is the adhesive layer, typically made of EVA (ethylene-vinyl acetate copolymer). EVA is a difficult component to effectively dispose of during solar panel recycling.

[0005] Microwaves are electromagnetic waves with frequencies ranging from 300MHz to 300GHz. Commonly used microwave power frequencies are 915MHz, 2450MHz, and 5800MHz. They can generate heat by causing friction between molecules in polar substances. Microwave processing is an emerging solar panel recycling technology that can effectively separate the various components of a solar panel for recycling and reuse. The appropriate technology can be selected based on the shape, size, and moisture content of the material being heated. Microwave heating makes the object itself the heat source, eliminating the need for heat conduction. It heats both the inside and outside simultaneously, thus achieving a heating effect in a short time. Furthermore, during microwave heating, electromagnetic waves typically penetrate all parts of the object evenly, generating heat and significantly improving uniformity. In microwave heating, microwave energy is only absorbed by the object being heated; the air in the heating chamber and the corresponding containers do not heat up, resulting in extremely high thermal efficiency and a significantly improved production environment.

[0006] Compared to traditional heat treatment methods, microwave processing offers higher efficiency and lower energy consumption. Microwave processing utilizes the heating properties of microwaves to induce physical or chemical changes in different materials within a solar panel at varying temperatures, thereby achieving separation. In light of the aforementioned issues, it is necessary to propose a method for recovering the adhesive layer material from solar panels using a mass-production-ready architecture to address these problems. Summary of the Invention

[0007] Microwave processing utilizes the heating properties of microwaves to cause physical or chemical changes in different materials within a solar panel at varying temperatures, thereby achieving separation. The purpose of this invention is to provide a method for recycling adhesive layer materials from solar panels, offering higher efficiency and lower energy consumption.

[0008] To achieve the main objective of this invention, the present invention provides a method for recycling adhesive layer material in a solar panel, comprising: a method for recycling adhesive layer material in a solar panel, comprising the following steps: Step 1: removing a metal frame of a solar panel; Step 2: heating the solar panel using a microwave heating process, heating the upper adhesive layer material and the lower adhesive layer material of the solar panel; Step 3: using a first mechanical tool to separate a glass sheet of the solar panel from the wafer assembly on the solar panel, and scraping off the upper adhesive layer material on the glass sheet to recycle the glass sheet and the upper adhesive layer material of the solar panel; and Step 4: using a second mechanical tool to separate a backplate of the solar panel from the wafer assembly on the solar panel, and scraping off the lower adhesive layer material on the backplate to recycle the backplate and the lower adhesive layer material of the solar panel.

[0009] According to one feature of the present invention, in step two, the solar panel is placed on a conveyor belt and enters a continuous microwave heating cavity to perform the microwave heating process, so as to heat the upper adhesive layer material and the lower adhesive layer material of the solar panel.

[0010] According to one feature of the present invention, in step two, the microwave heating process heats the upper adhesive layer material and the lower adhesive layer material of the solar panel to between 180 degrees and 250 degrees.

[0011] According to one feature of the invention, in step three, the first mechanical device has at least one suction cup for holding the glass sheet of the solar panel and separating it from the wafer assembly on the solar panel.

[0012] According to one feature of the invention, in step three, the first mechanical device has at least one scraper for scraping off the upper adhesive layer material on the glass sheet after the glass sheet of the solar panel is separated from the wafer assembly on the solar panel.

[0013] According to one feature of the invention, in step four, the second mechanical device has at least one suction cup for adhering to the backplate of the solar panel and separating it from the wafer array on the solar panel.

[0014] According to one feature of the invention, in step four, the second mechanical device has at least one scraper for scraping off the lower adhesive layer material on the backplate after the backplate of the solar panel is separated from the wafer assembly on the solar panel.

[0015] According to one feature of the present invention, steps three and four are still performed in the continuous microwave heating cavity.

[0016] According to one feature of the present invention, the first mechanical device and the second mechanical device are made of non-metallic materials.

[0017] According to one feature of the present invention, the first mechanical device and the second mechanical device are made of ceramic material.

[0018] Microwaves can effectively separate the encapsulation materials from solar panels, facilitating the recycling of glass and solar cells. The advantages of this method for recycling adhesive layer materials from solar panels include: 1. Microwave processes can rapidly heat the solar panel, shortening recycling time; 2. Compared to traditional heat treatment, microwave processes require less energy, reducing recycling costs; 3. Microwave processes can effectively separate different materials within the solar panel, improving the purity of recycled materials and increasing their reuse value; 4. Microwave processes can reduce energy consumption and waste emissions, making them more environmentally friendly; and 5. In addition to glass and solar cells, microwave processes can also effectively recover valuable encapsulation materials.

[0019] Currently, solar panel recycling in Taiwan mainly relies on thermal treatment to separate the glass and solar cells for reuse. Microwave processing is an important development direction for solar panel recycling. With the maturity of the technology and the reduction of costs, microwave processing is expected to be widely used in solar panel recycling, improving recycling efficiency, reducing recycling costs, and achieving more environmentally friendly solar panel recycling. Simple Explanation of the Diagram

[0020] [Figure 1] is a schematic diagram showing a method for recycling adhesive layer material in a solar panel according to an embodiment of the present invention. Implementation

[0021] An embodiment of the present invention is illustrated with reference to Figure 1. This description is not intended to limit the embodiments of the present invention, but rather to illustrate one example. As shown in Figure 1, a schematic diagram of a method for recycling adhesive layer material in a solar panel according to an embodiment of the present invention is presented. The solar panel mainly consists of a glass sheet, a backsheet, an aluminum frame, a silicon crystal cell array, encapsulation material, and connecting wires. The glass sheet protects the cells, the aluminum frame provides support and fixation, and the encapsulation material is used to encapsulate all components together, ensuring the durability and airtightness of the solar panel. The encapsulation material that encapsulates all components together is the adhesive layer material, typically EVA (ethylene vinyl acetate copolymer).

[0022] This invention provides a method for recovering adhesive layer material in a solar panel, comprising the following steps: Step 1: removing a metal frame of a solar panel; Step 2: heating the solar panel using a microwave heating process, heating the upper adhesive layer material and the lower adhesive layer material of the solar panel; Step 3: using a first mechanical tool to separate a glass sheet of the solar panel from the wafer assembly on the solar panel, and scraping off the upper adhesive layer material on the glass sheet to recover the glass sheet and the upper adhesive layer material of the solar panel; and Step 4: using a second mechanical tool to separate a backplate of the solar panel from the wafer assembly on the solar panel, and scraping off the lower adhesive layer material on the backplate to recover the backplate and the lower adhesive layer material of the solar panel.

[0023] In step one, the removal of a metal frame from a solar panel can be achieved using automated machinery. This machinery removes the locking elements of the metal frame, allowing for easy recycling of the solar panel's metal frame. The metal frame can be made of aluminum or stainless steel.

[0024] After removing the solar panel from the metal frame, the glass sheet and the back panel need to be separated from the solar panel. The main task is to heat and seal the upper adhesive layer material and the lower adhesive layer material of the glass sheet and the back panel.

[0025] In step two, the solar panel, after its metal frame has been removed, is placed on a conveyor belt and enters a continuous microwave heating cavity for microwave heating to heat the upper and lower adhesive layers of the solar panel. Microwaves are electromagnetic waves with frequencies between 300MHz and 300GHz; commonly used microwave power frequencies are 915MHz, 2450MHz, and 5800MHz. In this invention, preferably, the microwave power frequency is 2450MHz. Due to the penetrating power of microwaves, they can easily penetrate the glass sheet and the backplate. The microwave heating process heats the upper and lower adhesive layers of the solar panel to between 180 and 250 degrees Celsius. Preferably, the upper and lower adhesive layers are heated to between 200 and 230 degrees Celsius.

[0026] In step three, a first mechanical device is used to separate a glass sheet from the wafer assembly on the solar panel and scrape off the upper adhesive layer material on the glass sheet to recover the glass sheet and the upper adhesive layer material of the solar panel. To separate the glass sheet of the solar panel, in this invention, the first mechanical device has at least one suction cup to hold the glass sheet of the solar panel and separate it from the wafer assembly on the solar panel. Then, the first mechanical device has at least one scraper to scrape off the upper adhesive layer material on the glass sheet after it has been separated from the wafer assembly on the solar panel.

[0027] Since the glass sheet and the back panel of the solar panel are attached to both sides of the solar panel, step three further includes flipping the solar panel 180 degrees up and down so that the back panel of the solar panel faces upward.

[0028] In step four, a second mechanical device is used to separate the backsheet of the solar panel from the wafer assembly on the solar panel, and to scrape off the lower adhesive layer material on the backsheet to recover the backsheet and the lower adhesive layer material of the solar panel. To separate the backsheet of the solar panel, in this invention, the second mechanical device has at least one suction cup to hold the backsheet of the solar panel and separate it from the wafer assembly on the solar panel. Then, the second mechanical device has at least one scraper to scrape off the lower adhesive layer material on the backsheet after the backsheet of the solar panel has been separated from the wafer assembly on the solar panel.

[0029] It should be noted that steps three and four of the present invention are still performed within the continuous microwave heating cavity. Therefore, the first and second mechanical devices are disposed within the continuous microwave heating cavity. To avoid interference with the microwaves caused by the first and second mechanical devices, they are made of non-metallic materials. Preferably, they are made of ceramic materials. That is, the suction cups and scrapers of the first and second mechanical devices are preferably made of ceramic materials.

[0030] Microwaves can effectively separate the encapsulation materials from solar panels, facilitating the recycling of glass and solar cells. The advantages of this method for recycling adhesive layer materials from solar panels include: 1. Microwave processes can rapidly heat the solar panel, shortening recycling time; 2. Compared to traditional heat treatment, microwave processes require less energy, reducing recycling costs; 3. Microwave processes can effectively separate different materials within the solar panel, improving the purity of recycled materials and increasing their reuse value; 4. Microwave processes can reduce energy consumption and waste emissions, making them more environmentally friendly; and 5. In addition to glass and solar cells, microwave processes can also effectively recover valuable encapsulation materials.

[0031] Currently, solar panel recycling in Taiwan primarily relies on thermal treatment to separate the glass and solar cells for reuse. Microwave processing represents a significant future direction for solar panel recycling. With technological advancements and cost reductions, microwave processing is expected to see widespread application in solar panel recycling, improving recycling efficiency, lowering costs, and achieving more environmentally friendly solar panel recycling.

[0032] The above description and explanation are merely illustrative of preferred embodiments of the present invention. Those skilled in the art may make other modifications based on the following defined scope of the patent application and the above description, but such modifications should still be within the spirit of the invention and the scope of the invention.

Claims

1. A method for recovering adhesive layer material in a solar panel, comprising the following steps: Step 1: removing a metal frame of a solar panel; Step 2: placing the solar panel on a conveyor belt and entering a continuous microwave heating cavity, heating the solar panel using a microwave heating process, heating the upper adhesive layer material and the lower adhesive layer material of the solar panel; Step 3: using a first mechanical device to separate a glass sheet of the solar panel from the wafer assembly on the solar panel, and scraping off the upper adhesive layer material on the glass sheet to recover the glass sheet and the upper adhesive layer material of the solar panel; and Step 4: using a second mechanical device to separate a backplate of the solar panel from the wafer assembly on the solar panel, and scraping off the lower adhesive layer material on the backplate to recover the backplate and the lower adhesive layer material of the solar panel; wherein, Steps three and four are still performed in the continuous microwave heating cavity. The first and second mechanical devices are made of non-metallic materials. Step three further includes rotating the solar panel 180 degrees up and down so that the back of the solar panel faces upward.

2. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein the frequency of the microwave is selected from one of 915 MHz, 2450 MHz and 5800 MHz.

3. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein in step two, the microwave heating process heats the upper adhesive layer material and the lower adhesive layer material of the solar panel to between 180 degrees and 250 degrees.

4. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein in step three, the first machine has at least one suction cup for holding the glass sheet of the solar panel and separating it from the wafer assembly on the solar panel.

5. The method for recovering adhesive layer material in a solar panel as claimed in claim 1, wherein in step three, the first machine has at least one scraper for scraping off the upper adhesive layer material on the glass sheet after the glass sheet of the solar panel is separated from the wafer assembly on the solar panel.

6. The method for recovering adhesive layer material in a solar panel as claimed in claim 1, wherein in step four, the second machine has at least one suction cup for adhering to the back sheet of the solar panel and separating it from the wafer assembly on the solar panel.

7. The method for recovering adhesive layer material in a solar panel as claimed in claim 1, wherein in step four, the second machine has at least one scraper for scraping off the lower adhesive layer material on the backplate after the backplate of the solar panel is separated from the wafer assembly on the solar panel.

8. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein the microwave heating process heats the upper adhesive layer material and the lower adhesive layer material of the solar panel to between 180 degrees and 250 degrees.

9. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein the microwave heating process heats the upper adhesive layer material and the lower adhesive layer material of the solar panel to between 200 degrees and 230 degrees.

10. The method for recycling adhesive layer material in a solar panel as claimed in claim 1, wherein the first mechanical device and the second mechanical device are made of ceramic material.

Images