Methods for disposing of waste solar cells

Abstract

To provide a method for efficiently treating a waste solar cell.SOLUTION: A method for treating a waste solar cell is a method for continuously treating a waste solar cell including a heating step of heating a solar cell module (C) having a resin back sheet and a sealing resin layer in a thermal decomposition furnace, and thereby melting a resin component contained in the solar cell module (C) and decomposing oxidation, wherein the heating step feeds hot air to a gap between the porous material (B) and inside a porous ceramic support (A), and a gap between the solar cell module (C) and the porous ceramic support (A) from the side of the porous material (B), in a state where the solar cell module (C) on the porous ceramic support (A) while separated from the porous ceramic support (A) and the porous ceramic support (A) is stacked on the carried porous material (B) carrying a transition metal oxide.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for treating waste solar cells. More specifically, it relates to a treatment method for efficiently removing resin components such as a backsheet and a sealing resin layer from a solar cell module, and recovering valuable materials such as conductive materials and aluminum frames derived from glass, cells, and electrodes.

Background Art

[0002] In order to realize a low-carbon society, the acceleration of CO2 reduction by utilizing renewable energy such as solar power generation is underway. While the introduction of solar power generation is progressing significantly, issues regarding the recycling of solar cell modules at the time of disposal have been pointed out.

[0003] The structure of a general solar cell module consists of three layers: a surface of tempered glass, a sealing resin layer inside, and a backsheet on the back. Wires (interconnectors) that connect the cells are wired in the sealing resin layer. The sealing resin is required to have transparency, flexibility, adhesiveness, tensile strength, and weather resistance, etc., and ethylene vinyl acetate copolymer (hereinafter abbreviated as "EVA") is generally used, and it plays a role of adhering the tempered glass, cells, and backsheet by heating and pressurizing. A technique for recycling a solar cell module has been proposed, in which the solar cell module is heated in an electric furnace or the like in an oxidizing atmosphere to thermally decompose EVA to remove the sealing material and separate the cell part and the glass substrate.

[0004] The present applicant has also proposed a method for recovering valuable materials from a solar cell module, in which the solar cell module is placed with the backsheet surface facing down on a porous molded body made of a heat-resistant material carrying a transition metal oxide as a catalyst, and the solar cell module is heated in a heating furnace in an oxidizing atmosphere with an oxygen concentration of 15% or more to melt the resin component and then burned (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. 2020 / 031661 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described in Patent Document 1, when attempting to heat the entire module on a porous molded body, there is a problem that the processing time is long because the temperature rise is gradual. On the other hand, in order to reduce processing costs, it is efficient to increase the number of modules processed per unit time, which necessitates shortening the processing time. However, if the processing speed is increased by raising the temperature inside the pyrolysis furnace, a new problem arises: it leads to an increase in processing costs such as fuel costs. [Means for solving the problem]

[0007] The inventors diligently conducted research to solve the aforementioned problems. As a result, they discovered that by providing a predetermined gap between the porous molded body and the module when heating the entire module on the porous molded body, and by sending hot air from the bottom of the porous molded body, it is possible to accelerate the temperature rise of the entire module, thereby improving the processing speed and shortening the processing time, thus completing the present invention.

[0008] In other words, the configuration of the present invention is as follows. [1] A method for continuously processing waste solar cells, comprising a heating step of heating a solar cell module (C) having a resin backsheet and a sealing resin layer in a pyrolysis furnace to melt and oxidize the resin components contained in the solar cell module (C), A method for processing waste solar cells, characterized in that, during the heating step, the solar cell module (C) is placed on a porous ceramic support (A) spaced apart from the porous ceramic support (A), and the porous ceramic support (A) is stacked on a porous material (B) on which a transition metal oxide is supported, and hot air is blown from the side of the porous material (B) into the porous material (B), the inside of the porous ceramic support (A), and the gap between the solar cell module (C) and the porous ceramic support (A).

[0009] [2] A method for processing waste solar cells according to [1], characterized in that a spacer member is installed between the porous ceramic support (A) and the solar cell module (C), or a lifting member for the solar cell module (C) is also installed on the top of the pyrolysis furnace to separate the solar cell module (C) from the porous ceramic support (A). [3] A method for processing waste solar cells according to [1] or [2], characterized in that the gap between the solar cell module (C) and the porous ceramic support (A) is in the range of 3 to 50 mm.

[0010] [4] A method for processing waste solar cells according to any one of [1] to [3], characterized in that the number of cells on the surface of the porous ceramic support (A) and the porous material (B) is in the range of 5 to 50 pixels per inch (hereinafter abbreviated as "ppi"). [5] A method for disposing of waste solar cells according to any one of items [1] to [4], wherein a mesh structure for preventing falls is installed below the solar cell module (C). [6] A method for processing waste solar cells according to any one of [1] to [5], wherein valuable materials are recovered after the heating step. [Effects of the Invention]

[0011] In this invention, heat can be efficiently transferred, thereby improving the processing speed of waste solar cells, shortening processing time, and efficiently recovering reusable valuable materials. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing one embodiment of the present invention. [Figure 2] This is a schematic diagram showing another embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating yet another embodiment of the present invention. [Figure 4] This graph shows the temperature change at the center under the backsheet of the solar cell modules in Examples 1-3 and Comparative Example 1. [Figure 5] This graph shows the temperature change at the center under the backsheet of the solar cell module in Examples 4-6. [Modes for carrying out the invention]

[0013] The present invention will be described in detail below. The present invention relates to a method for processing waste solar cells, which includes a heating step of heating a solar cell module (C) having a resin backsheet and a sealing resin layer in a pyrolysis furnace to melt and oxidize the resin components contained in the solar cell module (C), and is a method for continuously processing waste solar cells. During the heating process, the solar cell module (C) is placed on the porous ceramic support (A) at a distance from the porous ceramic support (A), and the porous ceramic support (A) is stacked on a porous material (B) on which a transition metal oxide is supported. Hot air is then blown from the porous material (B) side into the interior of the porous material (B) and the porous ceramic support (A), and into the gap between the solar cell module (C) and the porous ceramic support (A).

[0014] Fig. 1 shows an embodiment of the present invention. In Fig. 1, 1 represents a porous material (B) carrying a transition metal oxide, 2 represents a porous ceramic support (A), 3 represents a solar cell module (C), 4 represents a backsheet, 5 represents a sealing resin layer, 6 represents a cell, and 7 represents a tempered glass, which constitute the solar cell module 3. A predetermined gap d is provided between the porous ceramic support 2 and the solar cell module 3. In one aspect of the present invention, the cell 6 and the tempered glass 7 are recovered as valuable materials. Although not shown, metals and metal oxides constituting electrodes, reflective films, etc. are also recovered as valuable materials. The surface glass functions as a surface protective material.

[0015] <Solar cell module 3> Any solar cell module 3 applicable to the present invention can be used as long as it has a resin backsheet 4 that is not a double-sided glass type. Specifically, examples include single crystal silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, heterojunction solar cells, CIS solar cells, CIGS solar cells, CdTe solar cells, etc.

[0016] Although not shown in such a solar cell module 3, usually, as electrodes, for example, a light-transmissive electrode, a linear electrode, a ladder-shaped electrode, or an electrode formed by laminating a metal foil or metal ribbon serving as a bus bar on a chain-shaped electrode is used. Examples of the metal include silver, copper, or aluminum, etc. In addition, a transparent electrode mainly composed of a conductive oxide may be provided. As the conductive oxide, one or more transparent conductive films selected from the group consisting of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), aluminum gallium oxide (AGO), titanium-doped indium oxide (ITiO), indium gallium zinc oxide (IGZO), and hydrogen-doped indium oxide (In2O3) can also be used.

[0017] The solar cell module 3 is configured to seal a plurality of cells 6 with a resin layer 5 for sealing between a toughened glass 7 and a backsheet 4. As the resin for sealing, thermoplastic resins such as ethylene vinyl acetate (EVA), polyvinyl butyral resin (PVB), and polyolefin resin are used, and the cells 6 are sealed by laminating the cells 6 with a sheet made of the resin for sealing. The resin layer 5 for sealing may contain a coloring material such as a white pigment. The white pigment such as titanium oxide has a function of reflecting sunlight and increasing the incident light to the solar cell module 3. Such a white pigment may be kneaded into the resin for sealing, or a layer containing the white pigment may be laminated to form the resin layer 5 for sealing.

[0018] Further, the backsheet 4 is a sheet-like back protection material, and a base film of EVA or polyethylene terephthalate resin, or a laminated film of the base film and a weather-resistant fluorine polymer film such as polyvinyl fluoride (PVF) is used.

[0019] Furthermore, in order to protect the peripheral portion of the solar cell module 3, although not shown, an aluminum frame may be attached as a frame. Regarding the aluminum frame, since there is no need to cut the porous ceramic support 2 according to the size of the aluminum frame and the work becomes simple, the aluminum frame may be removed before thermal decomposition, or may be removed after thermal decomposition to reduce the possibility of the glass cracking during removal. In addition, a reflective film may be provided on the back surface, which is the opposite side of the sunlight incident surface of the solar cell module, if necessary, to improve the light reception efficiency of the cell. Specifically, the reflective film may be a metal film made of a metal such as aluminum or silver.

[0020] <Heating step> In the heating step in the treatment method of the present invention, the solar cell module 3 having the resin-made backsheet 4 and the resin layer 5 for sealing is heated in a thermal decomposition furnace to melt and oxidatively decompose the resin components contained in the solar cell module 3. This oxidative decomposition usually involves the combustion of the resin components.

[0021] In the heating step, the solar cell modules 3 are placed on the porous ceramic support 2 at intervals such that a predetermined gap is provided between them, and the porous ceramic support 2 is placed on the porous material 1 on which the transition metal oxide is supported. With this arrangement, the modules are moved through the furnace from the inlet to the outlet. At this time, it is preferable to position the solar cell modules 3 with the back sheet 4 facing downwards, so as to face the porous ceramic support 2, in order to recover valuable materials.

[0022] In the heating process of the present invention, hot air is blown in from the porous material 1 side. The hot air passes through the pores of the porous material 1 and the porous ceramic support 2, reaches the gap with the solar cell module 3, collides with the solar cell module 3, and diffuses into the gap d.

[0023] Furthermore, in order to improve processing efficiency, it is preferable to move multiple solar cell modules 3 continuously so that multiple solar cell modules 3 are being heated in the pyrolysis furnace. When heat-treating the workpiece consisting of the solar cell modules 3, porous ceramic support 2, and porous material 1, they may be placed in a gridded iron tray or the like to prevent them from collapsing or tipping over during movement within the furnace.

[0024] The gap d can be provided, for example, by installing a spacer member 8 between the porous ceramic support 2 and the solar cell module 3, as shown in Figure 2, or by installing a lifting member 9 for the solar cell module 3 on top of the pyrolysis furnace, as shown in Figure 3.

[0025] The spacer member 8 is not particularly limited in shape or form as long as it can provide a predetermined gap. For example, it may be lattice-shaped, spherical, or rod-shaped, and should be placed on the porous ceramic support 2 so that the solar cell module 3 does not bend. Furthermore, the lifting member 9 is not particularly limited as long as it is configured to lift the solar cell module 3 from above, and cage materials can also be used. These members are usually made of fire-resistant materials that do not deform or react when heated, and are made of inorganic materials such as stainless steel, silica, or alumina.

[0026] The gap d between the solar cell module 3 and the porous ceramic support 2 is preferably in the range of 3 to 50 mm, preferably 4 to 40 mm, and more preferably 5 to 15 mm. Within this range, it is selected according to the air permeability of the porous ceramic support 2 and the porous material 1, and the amount of hot air supplied. Unless otherwise specified, "~" indicates greater than or equal to less than or equal to. During the heating process, the resin components such as EVA and PET that make up the backsheet 4 and the sealing resin layer 5 melt and then flow out toward the porous ceramic support 2 due to the action of gravity.

[0027] Because the porous ceramic support 2 is porous, the molten resin components that flow down have a large contact area with the atmosphere inside the heating furnace, allowing them to capture components such as white pigment that are contained as solid matter. The molten resin components flow down, pass through the porous ceramic support 2, reach the porous material 1, and are oxidatively decomposed by the supported transition metal oxide, with the decomposed products burning. This configuration suppresses the generation of soot.

[0028] For the aforementioned oxidative decomposition, it is desirable that the atmosphere inside the heating furnace during the heating process be controlled to an oxygen concentration of 6 vol% or more and less than 15 vol%. This range is desirable because it allows for gentle and stable combustion and removal of the resin components.

[0029] The temperature of the pyrolysis furnace is appropriately determined according to the resins that make up the backsheet 4 and the sealing resin layer 5, but is preferably 425 to 575°C. If the temperature is 425°C or higher, it will be higher than the pyrolysis temperature of the resins used in the backsheet 4 and the sealing resin layer 5, and combustion will occur. If the temperature is 575°C or lower, rapid combustion can be suppressed, and damage to the glass of the solar cell module 3 can be prevented.

[0030] The pyrolysis furnace is not particularly limited as long as it is a pyrolysis furnace such as a gas furnace or electric furnace that can achieve the above temperature and into which the material to be processed, including the porous material 1, the porous ceramic support 2, and the solar cell module 3, can be introduced. Any known pyrolysis furnace can be used.

[0031] Methods for supplying hot air include heating an oxygen-containing gas with a gas burner or the like and supplying it from the porous material 1 side. While there are no particular limitations as long as the furnace temperature can be achieved, for example, in the case of a gas furnace, the entire furnace may be heated at the same time as the hot air is supplied.

[0032] In the method of the present invention, it is preferable to recover the valuable material remaining on the porous ceramic support 2 after the heating step. The valuable material is at least one selected from the group consisting of glass, cells, conductive materials used for electrodes, and aluminum frames.

[0033] In the method of the present invention, in order to efficiently recover the valuable material, it is also effective to install a wire mesh or the like between the solar cell module 3 and the porous ceramic support 2, so that even if the resin melts and moves to the porous ceramic support 2, the remaining valuable material can be recovered together with the wire mesh. As a result, the processed material after the resin has melted and burned can be recovered without the glass, cells, etc., falling apart.

[0034] <Porous ceramic support 2> The porous ceramic support 2 applicable to the present invention can be used without any limitations as long as it is stable at the above temperature (specifically, around 425°C to 575°C) and has a porous structure. Specific materials include stable and common ceramic materials such as alumina, zirconia, silicon nitride, silicon carbide, cordierite, ferrite, barium titanate, lead zirconate titanate, forsterite, zircon, mullite, steatite, and aluminum nitride.

[0035] There are no particular restrictions on the pore size of the porous ceramic support 2, but a size of approximately 0.1 to 5 mm is preferable as it allows for easy penetration when EVA and PET melt at around 450°C. There are no particular restrictions on the number of cells on the surface, but a size of 5 to 50 pixels per inch (hereinafter abbreviated as "ppi") is desirable. There are no restrictions on the porosity, but a size of approximately 50 to 95% is desirable. In particular, a three-dimensional skeletal structure with continuous pores can be suitably used.

[0036] There are no particular restrictions on the shape of the porous ceramic support 2, but a plate-shaped support is preferably used in order to prevent the resin used in the solar cell module 3 from falling off. Furthermore, from the viewpoint of suppressing the generation of soot caused by molten resin components leaking out of the porous ceramic support 2, the size (area) of the surface on which the backsheet 4 of the porous ceramic support 2 is mounted is preferably as large as possible within the range that fits within the aluminum frame when the aluminum frame has not been removed, and preferably larger than the bottom area of ​​the backsheet 4 when the aluminum frame has been removed from the solar cell module 3.

[0037] There are no restrictions on the thickness of the porous ceramic support 2, but a thickness of approximately 10 to 60 mm is preferred.

[0038] Suitable porous ceramic support 2 as described above includes products made of alumina, silicon carbide, and cordierite, such as ceramic foam, ceramic filters, or ceramic foam filters.

[0039] When processing waste solar cells using the method of the present invention, the solar cell module 3 is placed on the porous ceramic support 2 with its backsheet 4 facing downwards. By placing the backsheet 4 facing downwards, the resin components constituting the backsheet 4 and the sealing resin layer 5 melt due to heating and then flow out toward the porous ceramic support 2 due to the action of gravity.

[0040] Because the porous ceramic support 2 is porous, the resin that flows down has a larger contact area with the atmosphere inside the pyrolysis furnace. As a result, the efficiency of combustion through further heating is increased, and the generation of soot can be suppressed.

[0041] <Porous material 1> In the porous material 1 supported by a transition metal oxide used in the present invention, the transition metal oxide has the ability to adsorb oxygen in an oxidized state and decompose organic compounds having aromatic rings that are produced when aromatic resins are oxidatively decomposed during combustion. By using such a porous material 1, the generation of soot can be suppressed.

[0042] As the transition metal oxide, for example, oxides of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury can be used without any limitations.

[0043] Among these, oxides of first transition elements such as scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, and copper are preferred; oxides of second transition elements such as yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, and silver are preferred; and oxides of third transition elements such as lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold are preferred. More preferably, transition metal oxides such as rutile-type or anatase-type titanium(IV) oxide, chromium(III) oxide, iron(III) oxide, and copper(II) oxide can be suitably used. These may also be in the form of composite oxides.

[0044] The porous material 1 can be any material that is stable at the combustion temperature of the resin component, similar to the porous ceramic support 2, and can be any material of the same type. The shape of the porous material 1 is not particularly limited, as long as it can be used as a so-called catalyst carrier, but it is more preferable that it be a plate-shaped porous molded body similar to the porous ceramic support 2 on which the solar cell module 3 is mounted.

[0045] The method for supporting the transition metal oxide on the porous material 1 can be any known technique without any limitations. Specifically, a common method involves impregnating the porous material 1 with a solution containing the transition metal oxide using dip coating, wash coating, spray coating, or spin coating. The simplest method is to then remove the solution by heating it to above its boiling point. Alternatively, thermal spraying technology may be used to spray molten transition metal oxide onto the porous material 1.

[0046] In this invention, a porous ceramic support 2 is placed on a porous material 1 on which the transition metal oxide is supported.

[0047] Regarding the size of the porous material 1, from the viewpoint of the stability of the workpiece including the solar cell module 3, it is preferable that the loading surface of the porous material 1 is equal to or greater than the bottom area of ​​the porous ceramic support 2. The thickness of the porous material 1 is preferably about 10 to 60 mm. The number of cells on the surface of the porous material 1 is preferably in the range of 5 to 50 pixels per inch (hereinafter abbreviated as "ppi"), similar to the porous ceramic support 2. There are no restrictions on the porosity, but it is preferable that it be about 50 to 95%, similar to the porous ceramic support 2. In particular, a three-dimensional skeletal structure with continuous pores can be preferably used. [Examples]

[0048] The following describes embodiments of the recovery method of the present invention with reference to examples, but the present invention is not limited to the following embodiments, and can be modified and implemented as appropriate without departing from the spirit of the invention.

[0049] The shelf used in this invention is heat-resistant and can heat the mounted solar cell module 3, porous ceramic support 2, and porous material 1. Examples include ceramic shelf boards and stainless steel wire mesh.

[0050] [Example 1] For the solar cell module 3, we used Kyocera's polycrystalline silicon solar cell "KD270HX-BPEFMS" for evaluation. The electrodes and aluminum frame attached to the backsheet 4 were removed before the heat treatment process.

[0051] As the porous ceramic support 2, a ceramic filter (manufacturer: Nippon Rutsubo (material: silicon carbide), 10 ppi, 300 mm x 400 mm x 15 mmt) was used (this will be referred to as the porous ceramic support (A-1)).

[0052] The porous material 1 supporting the catalyst was a ceramic filter measuring 300mm x 400mm x 45mmt (manufacturer: Nippon Rutsubo, material: silicon carbide) 10ppi. Chromium(III) oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was suspended in water and stirred while the ceramic filter was immersed in the solution to perform a dip coating. The filter was then dried at 450°C to produce chromium-supported porous material (B-1). The mass of chromium-supported porous material (B-1) before coating was 2300g, and the mass after coating and drying was 2859g.

[0053] A steel tray measuring 2,100 mm x 1,210 mm x 50 mm with a grid-like base was fabricated, and the chromium-supported porous material (B-1) was placed on it. A porous ceramic support (A-1) was then placed on top of it. Furthermore, stainless steel grid-type spacers (grid spacing: 160 mm, height: 10 mm) were placed on top of the porous ceramic support (A-1) as spacer members 8 to create a predetermined spacing, and the solar cell module 3 was placed on top of the grid-type spacers with the back sheet 4 facing downwards.

[0054] A gas furnace was used as the pyrolysis furnace. This gas furnace was a tact-feed chain blow type with a furnace length of 5,400 mm, internal width of 2,300 mm, and internal height of 280 mm, employing a hot air circulation heat treatment system. A metallic burner MJPE-200K was used in the gas burner section, burning a mixture of LP gas and air to heat it. The heated mixture was then fed by an Adachi Kiko "6.0-LF limit load fan" (450 m 3 Hot air was supplied from the bottom of the pyrolysis furnace section through a slit at a pressure of 2.0 kPa and 30 kW, and forcefully blown onto the chromium-supported porous material (B-1). The oxygen concentration inside the pyrolysis furnace was controlled to be between 6 vol% and less than 15 vol%. The furnace temperature was controlled to 490°C, and the heat treatment was performed for 20 minutes. The change in furnace temperature was evaluated at the temperature in the lower center of the backsheet 4 of the solar cell module 3.

[0055] [Example 2] Instead of the stainless steel grid-type spacer used in Example 1 as spacer member 8, a stainless steel grid-type spacer with (grid spacing: 160 mm, height: 20 mm) was used, and the same heat treatment as in Example 1 was performed.

[0056] [Example 3] Instead of the stainless steel grid-type spacer used in Example 1, a stainless steel grid-type spacer with a grid spacing of 160 mm and a height of 30 mm was used, and the same heat treatment as in Example 1 was performed.

[0057] [Comparative Example 1] The same heat treatment as in Example 1 was performed, except that a stainless steel grid-type spacer was not used.

[0058] Figure 4 shows the change in furnace temperature with respect to heating time during the heat treatment in Examples 1-3 and Comparative Example 1.

[0059] In all cases, a peak in furnace temperature was observed during combustion. However, in Examples 1-3, where a predetermined gap was provided, an evaluation of the difference in peak time compared to Comparative Example 1, where no gap was provided, revealed that in all examples, the time at which the furnace temperature peaked was earlier than in Comparative Example 1. Specifically, compared to Comparative Example 1, where no gap was provided, the peak time was 126 seconds earlier in Example 1 and 104 seconds earlier in Examples 2 and 3, indicating that heating was achieved in a shorter time and processing efficiency was increased.

[0060] [Example 4] In Example 1, a ceramic filter was used as the porous ceramic support 2, manufactured by Nippon Rutsubo (material: silicon carbide), with a density of 7 ppi, measuring 300 mm x 400 mm x 15 mmt (referred to as porous ceramic support (A-2)).

[0061] As the porous material 1 supporting the catalyst, a ceramic filter (manufacturer: Nippon Rutsubo, material: silicon carbide, 7 ppi, 300 mm × 400 mm × 45 mm t) was used, and a chromium-supported porous material (B-2) was prepared using chromium(III) oxide, similar to Example 1. The mass of the chromium-supported porous material (B-2) before coating was 2300 g, and the mass after coating and drying was 2859 g.

[0062] The chromium-supported porous material (B-2) and the porous ceramic support (A-2) were installed in the same manner as in Example 1. Furthermore, a stainless steel grid-type spacer (grid spacing: 160 mm, height: 10 mm) was placed on top of the porous ceramic support (A-2) as a spacer member 8 to create a predetermined spacing, and the solar cell module 3 was installed on top of the grid-type spacer with the back sheet 4 facing downwards.

[0063] A gas furnace was used as the pyrolysis furnace. Hot air was supplied by narrowing it through a slit from the bottom of the pyrolysis furnace section used in Example 1 and vigorously blowing it onto the chromium-supported porous material (B-2). Without controlling the oxygen concentration inside the pyrolysis furnace, the temperature inside the furnace was controlled to 500°C and the heat treatment was performed for 15 minutes.

[0064] [Example 5] Instead of the stainless steel grid-type spacer used in Example 4 as spacer member 8, a stainless steel grid-type spacer with (grid spacing: 160 mm, height: 30 mm) was used, and the same heat treatment as in Example 4 was performed.

[0065] [Example 6] Instead of the stainless steel grid-type spacer used in Example 4 as spacer member 8, a stainless steel grid-type spacer with (grid spacing: 160 mm, height: 40 mm) was used, and the same heat treatment as in Example 4 was performed.

[0066] Figure 5 shows the change in temperature with respect to heating time during the heating process in Examples 4 to 6.

[0067] As a result, Example 4, in which the gap is 10 mm, 5 and 6 It was found that the time of peak maximum occurred 30 seconds earlier. The change was the same for gaps of 30 mm and 40 mm, suggesting that increasing the gap further would not make any difference.

[0068] This suggests that even with increased spacing, the amount of airflow hitting the solar cell modules remains unchanged, resulting in no difference in the thermal decomposition time. Therefore, it is highly significant to establish an optimal spacing. [Explanation of symbols]

[0069] 1: Porous material 2: Porous ceramic support 3: Solar cell modules 4: Back seat 5: Sealing resin layer 6: Cell 7: Tempered glass 8: Spacer component 9: Lifting component

Claims

1. A method for continuously processing waste solar cells, comprising a heating step of heating a solar cell module (C) having a resin backsheet and a sealing resin layer in a pyrolysis furnace to melt and oxidize the resin components contained in the solar cell module (C), A method for processing waste solar cells, characterized in that, during the heating step, the solar cell module (C) is placed on a porous ceramic support (A) at a distance from the porous ceramic support (A), the gap between the solar cell module (C) and the porous ceramic support (A) is in the range of 3 to 50 mm, and the porous ceramic support (A) is stacked on a porous material (B) on which a transition metal oxide is supported, and hot air is blown from the side of the porous material (B) into the porous material (B), the inside of the porous ceramic support (A), and the gap between the solar cell module (C) and the porous ceramic support (A).

2. A method for processing waste solar cells according to claim 1, characterized in that a spacer member is installed between the porous ceramic support (A) and the solar cell module (C), or a lifting member for the solar cell module (C) is installed on top of the pyrolysis furnace to separate the solar cell module (C) from the porous ceramic support (A).

3. A method for processing waste solar cells according to claim 1 or 2, characterized in that the number of cells on the surface of the porous ceramic support (A) and the porous material (B) is in the range of 5 to 50 pixels per inch (hereinafter abbreviated as "ppi").

4. A method for processing waste solar cells according to any one of claims 1 to 3, wherein a mesh structure for preventing falls is installed below the solar cell module (C).

5. A method for processing waste solar cells according to any one of claims 1 to 4, wherein valuable materials are recovered after the heating step.

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