Solar cell module resource recovery method

Abstract

To provide a method for more easily recovering resources from photovoltaic modules. [Solution] The method includes a crushing step S1 in which the photovoltaic module 100 is crushed while the photovoltaic cells 10 having a perovskite structure, the sealing material 20, the back sheet 30, and the light-transmitting sheet 40 are integrated together, and a separation step S2 in which the crushed material produced in the crushing step is rubbed together to turn the photovoltaic cells 10 in the crushed material into a powder and separate fragments of the sealing material 20, fragments of the back sheet 30, and fragments of the light-transmitting sheet 40 from one another, and in the separation step S2, the crushed material is introduced into a peptide solution and stirred.

Description

[Technical Field]

[0001] The present invention relates to a method for recovering resources from photovoltaic modules. [Background technology]

[0002] Solar cells generate electricity using the clean energy of sunlight, and are therefore considered effective in reducing the burden on the environment. The solar cell module contained in a solar cell comprises a solar cell that realizes photoelectric conversion, an encapsulant that seals the solar cell, a glass substrate that protects the front of the solar cell, and a backsheet that protects the back of the solar cell. Solar cell modules deteriorate over time due to use in harsh environments exposed to sunlight, and they become subject to deterioration in light transmittance and mechanical properties, and therefore require replacement. However, there is a need to recover valuable resources from deteriorated solar cell modules and reuse them.

[0003] Patent Document 1 discloses a method for separating a photovoltaic module into its individual materials. In this method, first, a pre-process is performed in which the back sheet is mechanically peeled off from the photovoltaic module, then a separation process is performed in which the photovoltaic module from which the back sheet has been peeled is immersed in a stripping agent solution to separate the glass substrate from the photovoltaic module, and then a process is performed in which the encapsulant and photovoltaic cells are separated and recovered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-104406 Summary of the Invention [Problem to be solved by the invention]

[0005] The method described in Patent Document 1 requires a step of mechanically peeling off only the backsheet from the photovoltaic module, which is time-consuming.

[0006] Therefore, an object of the present invention is to provide a method for more easily recovering resources from photovoltaic modules. [Means for solving the problem]

[0007] The present invention is a method for recovering resources from a photovoltaic module including photovoltaic cells having a perovskite structure, a resin sealing material for sealing the photovoltaic cells, a back sheet provided on the back surface of the photovoltaic cells with the sealing material interposed therebetween, and a light-transmitting sheet provided on the front surface of the photovoltaic cells with the sealing material interposed therebetween, the method comprising the steps of: a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a crushing step of crushing the crushed materials produced in the crushing step. Drum or cylindrical and a separation step of rubbing the pulverized material by stirring or vibrating it in a container to turn the photovoltaic cells in the pulverized material into powder and separating the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from one another, wherein in the separation step, the pulverized material is put into a peptide solution to separate the pulverized material from one another. In the peptide solution Rub together by stirring or shaking.

[0008] The present invention also provides a method for recovering resources from a photovoltaic module including photovoltaic cells having a perovskite structure, a resin sealing material sealing the photovoltaic cells, a back sheet provided on the back surface of the photovoltaic cells with the sealing material interposed therebetween, and a light-transmitting sheet provided on the front surface of the photovoltaic cells with the sealing material interposed therebetween, the method comprising the steps of: wetting the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated together with a potassium iodide solution or ethanol; crushing the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated together after the wetting step; and crushing the crushed materials produced in the crushing step. Drum or cylindricaland a separation step of grinding the pulverized material by stirring or vibrating it in a container to turn the photovoltaic cells in the pulverized material into powder and separating fragments of the sealing material, fragments of the back sheet, and fragments of the light-transmitting sheet from one another in the pulverized material.

[0009] The present invention also provides a method for recovering resources from a photovoltaic module including photovoltaic cells having a perovskite structure, a resin sealing material that seals the photovoltaic cells, a back sheet that is provided on the back surface of the photovoltaic cells with the sealing material interposed therebetween, and a light-transmitting sheet that is provided on the front surface of the photovoltaic cells with the sealing material interposed therebetween, the method comprising the steps of: a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a crushing step of crushing the crushed materials produced in the crushing step. Drum or cylindrical and a separation step of rubbing the pulverized material together by stirring or vibrating it in a container to turn the photovoltaic cells in the pulverized material into a powder and separating the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet in the pulverized material from one another, wherein in the separation step, the pulverized material is rubbed together by stirring or vibrating it in a potassium iodide solution or ethanol.

[0010] The present invention also provides a method for recovering resources from a photovoltaic module including photovoltaic cells having a perovskite structure, a resin sealing material that seals the photovoltaic cells, a back sheet that is provided on the back surface of the photovoltaic cells with the sealing material interposed therebetween, and a light-transmitting sheet that is provided on the front surface of the photovoltaic cells with the sealing material interposed therebetween, the method comprising the steps of: a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a crushing step of crushing the crushed materials produced in the crushing step. Drum or cylindricaland a separation step of grinding the photovoltaic cells in the pulverized material by stirring or vibrating them in a container to turn them into a powder, and separating the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from one another in the pulverized material, wherein in the pulverization step, the photovoltaic module is pulverized in a potassium iodide solution or ethanol.

[0011] The present invention also provides a method for recovering resources from a photovoltaic module including photovoltaic cells having a perovskite structure, a resin sealing material that seals the photovoltaic cells, a back sheet that is provided on the back surface of the photovoltaic cells with the sealing material interposed therebetween, and a light-transmitting sheet that is provided on the front surface of the photovoltaic cells with the sealing material interposed therebetween, the method comprising the steps of: a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a crushing step of crushing the crushed materials produced in the crushing step. Drum or cylindrical The method further includes a separation step in which the pulverized material is ground by stirring or vibrating in a container to turn the photovoltaic cells in the pulverized material into a powder and separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from one another; and a precipitation step in which the powdered material of the photovoltaic cells, the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet obtained in the separation step are introduced into a peptide solution and precipitated. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a method for more easily recovering resources from a photovoltaic module. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view of a photovoltaic module used in an embodiment of the present invention. [Figure 2] 1 is a diagram showing the flow of a photovoltaic module resource recovery method according to a first embodiment of the present invention. [Figure 3]FIG. 10 is a diagram showing the flow of a photovoltaic module resource recovery method according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a photovoltaic module resource recovery method according to an embodiment of the present invention will be described with reference to the drawings.

[0015] First Embodiment First, a photovoltaic module resource recovery method according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view of a photovoltaic module 100 used in the first embodiment. As shown in Figure 1, the photovoltaic module 100 includes photovoltaic cells 10 that realize photoelectric conversion, a sealant 20 that seals the photovoltaic cells 10, a back sheet 30 that protects the back surfaces of the photovoltaic cells 10, and a light-transmitting sheet 40 that protects the front surfaces of the photovoltaic cells 10.

[0016] The solar cell 10 has a perovskite structure. Specifically, the perovskite structure of the solar cell 10 contains an organic group such as methylammonium, metals such as lead, tin, and bismuth, and halogens such as iodine, bromine, and chlorine. The metal is located at the center of the crystal structure, and six halogens form an octahedron surrounding the metal. Eight organic positive ions are arranged in a hexahedron around the octahedron to complete the perovskite structure. The formula of the perovskite structure, made from methylammonium (CH3NH3), lead (Pb), and iodine (I), is CH3NH3PbI3. Here, we will explain the case where iodine is used as the halogen.

[0017] The encapsulant 20 is a resin sheet that has excellent transparency, flexibility, adhesiveness, tensile strength, and weather resistance, such as an ethylene-vinyl acetate copolymer (EVA) sheet or a polyvinyl butyral (PVB) sheet. In the photovoltaic module 100, the photovoltaic cells 10 are sandwiched between the encapsulant 20. The encapsulant 20 has adhesive properties and is bonded to the back sheet 30 and the light-transmitting sheet 40.

[0018] The back sheet 30 is a resin sheet made by laminating, for example, fluorine-based resin or polyester-based resin, and is provided on the back surface of the photovoltaic cell 10 via a sealing material 20. The back sheet 30 is required to be weather-resistant and moisture-resistant because it will be exposed to the outdoor environment.

[0019] The light-transmitting sheet 40 is made of glass and is provided on the front surface of the photovoltaic cell 10 via the sealing material 20. Like the back sheet 30, the light-transmitting sheet 40 is required to be weather-resistant and moisture-resistant because it will be exposed to the outdoor environment. The light-transmitting sheet 40 is also required to be transparent so as to transmit as much sunlight as possible. The light-transmitting sheet 40 is not limited to being made of glass, and may be made of a transparent resin.

[0020] In this embodiment, valuable resources are recovered from the photovoltaic module 100. Examples of valuable resources in the photovoltaic module 100 include halogens such as iodine (I), glass, and the like.

[0021] Fig. 2 is a diagram showing the flow of the photovoltaic module resource recovery method according to this embodiment. As shown in Fig. 2, the photovoltaic module resource recovery method includes a crushing step S1, a separation step S2, a sedimentation step S3, and a resource recovery step S4.

[0022] In the pulverization step S1, the photovoltaic cell module 100 is pulverized. For example, a crushing mill can be used for pulverization. In the pulverization step S1, the photovoltaic cell module 100 is pulverized into fine particles of about 1 mm to 10 mm, more preferably about 3 mm to 5 mm.

[0023] The crushing is performed while the photovoltaic cells 10, the encapsulant 20, the back sheet 30, and the light-transmitting sheet 40 remain integrated together. That is, in the crushing step S1, crushed material is generated in which fragments of the photovoltaic cells 10, fragments of the encapsulant 20, fragments of the back sheet 30, and fragments of the light-transmitting sheet 40 are integrated together.

[0024] When the photovoltaic module 100 includes a frame (not shown) for assembling the photovoltaic cells 10, the encapsulant 20, the back sheet 30, and the translucent sheet 40, it is preferable to remove the frame from the photovoltaic module 100 before the crushing step S1.

[0025] The frame is provided between the back sheet 30 and the light-transmitting sheet 40. The frame is provided along the peripheries of the back sheet 30 and the light-transmitting sheet 40, and is used to protect the peripheries of the back sheet 30 and the light-transmitting sheet 40 and to secure adjacent photovoltaic modules 100. The frame is a frame made of metal such as iron, stainless steel, or aluminum. From the viewpoints of light weight, thermal conductivity, etc., it is more preferable that the frame be made of aluminum.

[0026] In the separation step S2, the pulverized material produced in the pulverization step S1 is rubbed together. By rubbing the pulverized material together, the photovoltaic cells 10 in the pulverized material are turned into powder, and the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 in the pulverized material are separated from one another.

[0027] The grinding of the pulverized materials may be by stirring or vibration. The vibration method includes ultrasonic vibration, etc. The ultrasonic vibration may be one cycle or a combination of two or more cycles. The grinding of the pulverized materials may be carried out in a drum-type container, a cylindrical container, or other container.

[0028] In the precipitation step S3, the powdered material of the solar cell 10, the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 obtained in the separation step S2 are put into a solution and allowed to precipitate. The powdered material of the solar cell 10, the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 precipitate in descending order of specific gravity.

[0029] Specifically, the specific gravity of the glass used in the light-transmitting sheet 40 is approximately 2.5, the specific gravity of CH3NH3PbI3 used in the solar cell 10 is approximately 1.37, the specific gravity of the resin used in the back sheet 30 is approximately 1.1 to 2.17 (for example, the specific gravity of fluorine-based resin is approximately 2.12 to 2.17, and the specific gravity of polyester-based resin is approximately 1.1 to 1.4), and the specific gravity of the resin used in the encapsulant 20 is approximately 0.95 to 1.2 (for example, the specific gravity of EVA is approximately 0.95, and the specific gravity of PVB is approximately 1.05 to 1.2). Therefore, in the precipitation step S3, the fragments of the light-transmitting sheet 40, the powdery material of the solar cell 10, the fragments of the back sheet 30, and the fragments of the encapsulant 20 are precipitated in this order, or the fragments of the light-transmitting sheet 40, the fragments of the back sheet 30, the powdery material of the solar cell 10, and the fragments of the encapsulant 20 are precipitated in this order.

[0030] The liquid may be water or a solution. The solution may be a peptide solution, more specifically, a nattokinase solution. The peptide solution has the effect of promoting the precipitation of fine solids mixed in the solution. By using the peptide solution in the precipitation step S3, the time required for precipitation can be shortened, and the time required for resource recovery can be shortened.

[0031] The solution may be an aqueous solution of citric acid and chitosan. Citric acid is effective in condensing electrolytes. Chitosan (from crab and shrimp shells) has an insulating effect in addition to its condensing effect. Since the solar cell 10 may be electrically charged, chitosan can be added to insulate the fragments of the solar cell 10.

[0032] In the precipitation step S3, instead of putting the powdered material of the photovoltaic cells 10, the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 into a solution, the solution may be poured over the powdered material of the photovoltaic cells 10, the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40. Also, in the separation step S2, the pulverized materials may be rubbed together while being poured with a liquid.

[0033] In the resource recovery step S4, the fragments of the light-transmitting sheet 40, the powder of the photovoltaic cells 10, the fragments of the back sheet 30, and the fragments of the sealing material 20 that settled in the settling step S3 are recovered. Specifically, when the fragments of the light-transmitting sheet 40 settle in the liquid, the fragments of the light-transmitting sheet 40 (glass pellets) are recovered, when the powder of the photovoltaic cells 10 settles, the powder of the photovoltaic cells 10 is recovered, when the fragments of the back sheet 30 settle, the fragments of the back sheet 30 are recovered, and when the fragments of the sealing material 20 settle, the fragments of the sealing material 20 are recovered. The solution after the precipitate has been recovered can be reused in the precipitation step S3.

[0034] Well-known techniques can be used for resource recovery, such as gravity separation, melting point separation, or magnetic separation.

[0035] In the present embodiment described above, the crushed material is rubbed together to turn the photovoltaic cells 10 in the crushed material into powder, and the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 in the crushed material are separated from one another. This eliminates the need for a step of peeling only the back sheet 30 from the sealing material 20. This reduces the effort required and makes it easier to recover resources.

[0036] Second Embodiment Next, a photovoltaic module resource recovery method according to a second embodiment of the present invention will be described. The following mainly focuses on the differences from the first embodiment, and the same or corresponding components as those described in the first embodiment will be denoted by the same reference numerals in the drawings and will not be described again.

[0037] The photovoltaic module resource recovery method according to this embodiment is the same as that according to the first embodiment. and Similarly, it includes a crushing step S1, a separation step S2, a precipitation step S3, and a resource recovery step S4.

[0038] In the first embodiment, the separation step S2 is a dry process, but in this embodiment, the separation step S2 is a wet process. Specifically, in this embodiment, the pulverized material produced in the pulverization step S1 is put into a liquid, and the pulverized material is rubbed together in the liquid. The pulverized material may be rubbed together by stirring or vibration. Furthermore, the pulverized material may be rubbed together in a drum-type container, a cylindrical container, or another container.

[0039] The liquid may be water or a solution, such as a peptide solution, more specifically, a nattokinase solution, or a citric acid solution or a chitosan solution.

[0040] Furthermore, in the first embodiment, in the precipitation step S3, the powdered material of the photovoltaic cells 10, the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 separated in the separation step S2 are put into a liquid and allowed to precipitate. In this embodiment, the stirring or vibration in the separation step S2 is stopped, thereby allowing the powdered material of the photovoltaic cells 10, the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 to precipitate. When a peptide solution is used in the separation step S2, the time required for precipitation can be shortened, and the time required for resource recovery can also be shortened.

[0041] In the present embodiment described above, the crushed material is rubbed together in a liquid to turn the photovoltaic cells 10 in the crushed material into a powder, and the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 in the crushed material are separated from one another. This eliminates the need for a step of peeling only the back sheet 30 from the sealing material 20, and also eliminates the need for a step of putting the powdered photovoltaic cells 10, the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 into a liquid. This reduces the effort required and makes it easier to recover resources.

[0042] <Third embodiment> Next, a photovoltaic module resource recovery method according to a third embodiment of the present invention will be described. The following mainly focuses on the differences from the first and second embodiments, and the same or corresponding components as those described in the first and second embodiments will be denoted by the same reference numerals in the drawings and will not be described again.

[0043] 3 is a diagram showing the flow of the photovoltaic module resource recovery method according to this embodiment. As shown in Fig. 3, the photovoltaic module resource recovery method according to this embodiment includes a wetting step S31 before the crushing step S1.

[0044] In the wetting step S31, the photovoltaic module 100 is wetted in a potassium iodide solution or ethanol. The photovoltaic module 100 may be wetted by immersing the photovoltaic module 100 in a potassium iodide solution or ethanol, or by pouring the potassium iodide solution or ethanol onto the photovoltaic module 100. By immersing the photovoltaic module 100 in a potassium iodide solution or ethanol, or by pouring the potassium iodide solution or ethanol onto the photovoltaic module 100, the iodine contained in the perovskite structure is dissolved into the potassium iodide solution or ethanol. This makes it possible to separate and recover the iodine. The iodine can be recovered by adding hydrogen peroxide to the solution into which the iodine has dissolved.

[0045] In the wetting step S31, the photovoltaic module 100 is wetted in a potassium iodide solution or with ethanol, and then the photovoltaic module 100 is pulverized (pulverization step S1). When the photovoltaic module 100 is pulverized, the photovoltaic module may be wet or dry.

[0046] The steps from the separation step S2 onwards are almost the same as those in the first and second embodiments, and therefore a description thereof will be omitted here.

[0047] In this embodiment, by separating iodine, which is a structural substance of the perovskite structure, it is possible to easily recover other scarce resources with increased purity. Furthermore, even when a peptide solution is used in the separation step S2 or the precipitation step S3, the solar module 100 is wetted with a potassium iodide solution or ethanol before the separation step S2 or the precipitation step S3, so that the peptide solution and the potassium iodide solution or ethanol do not mix, and the purity of these solutions can be maintained.

[0048] <Fourth embodiment> Next, a photovoltaic module resource recovery method according to a fourth embodiment of the present invention will be described. The following mainly focuses on the differences from the third embodiment, and the same or corresponding components as those described in the first to third embodiments will be denoted by the same reference numerals in the drawings and will not be described again.

[0049] In the third embodiment, after a wetting step S31 in which the photovoltaic module 100 is wetted with a potassium iodide solution or ethanol, the photovoltaic module 100 is pulverized.

[0050] In this embodiment, the pulverized material produced by pulverizing the photovoltaic module 100 is placed in a potassium iodide solution or ethanol, and the pulverized material is rubbed together in the potassium iodide solution or ethanol (separation step S2). The pulverized material may be rubbed together by stirring or vibration. The pulverized material may be rubbed together in a drum-type container, a cylindrical container, or another container.

[0051] In this embodiment, stopping the stirring or vibration in the separation step S2 causes the powdered material of the photovoltaic cells 10, the fragments of the encapsulant 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 to settle. Therefore, the fragments of the light-transmitting sheet 40, the powdered material of the photovoltaic cells 10, the fragments of the back sheet 30, and the fragments of the encapsulant 20 can be collected.

[0052] Furthermore, during the stirring or vibration in the separation step S2, and after the stirring or vibration is stopped, the iodine contained in the perovskite structure dissolves in the potassium iodide solution or ethanol. This allows the iodine to be separated and recovered. The iodine is recovered by adding hydrogen peroxide to the solution into which the iodine has dissolved.

[0053] In the separation step S2, instead of putting the photovoltaic module 100 into the potassium iodide solution or ethanol, the powdered material of the photovoltaic cells 10, the fragments of the sealing material 20, the fragments of the back sheet 30, and the fragments of the light-transmitting sheet 40 may be poured into the potassium iodide solution or ethanol. Also, in the separation step S2, the pulverized materials may be rubbed together in the potassium iodide solution or while being poured with ethanol.

[0054] The steps from the precipitation step S3 onwards are almost the same as those in the first and second embodiments, and therefore a description thereof will be omitted here.

[0055] Fifth Embodiment Next, a photovoltaic module resource recovery method according to a fifth embodiment of the present invention will be described. The following mainly describes the differences from the third and fourth embodiments, and the same or corresponding components as those described in the first to fourth embodiments will be denoted by the same reference numerals in the drawings and will not be described again.

[0056] In a third embodiment, the photovoltaic module 100 is wetted with a potassium iodide solution or ethanol and then crushed. In a fourth embodiment, the photovoltaic module 100 is crushed and then the crushed material is placed in a potassium iodide solution or ethanol.

[0057] In this embodiment, the photovoltaic module 100 is placed in a potassium iodide solution or ethanol, and the photovoltaic module 100 is pulverized. That is, in the pulverization step S1, the photovoltaic module 100 is pulverized in the potassium iodide solution or ethanol. By pulverizing the photovoltaic module 100 in the potassium iodide solution or ethanol, the iodine contained in the perovskite structure is eluted into the potassium iodide solution or ethanol. Therefore, it is possible to separate and recover the iodine. The iodine is recovered by adding hydrogen peroxide to the solution into which the iodine has eluted.

[0058] In the crushing step S1, instead of putting the photovoltaic module 100 into the potassium iodide solution or ethanol, the photovoltaic module 100 may be crushed while the potassium iodide solution or ethanol is applied to the photovoltaic module 100. By recovering the potassium iodide solution or ethanol applied to the photovoltaic module 100, it becomes possible to separate and recover iodine.

[0059] The steps from the separation step S2 onwards are almost the same as those in the first and second embodiments, and therefore a description thereof will be omitted here.

[0060] Although the present embodiment has been described above, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that such modifications also fall within the technical scope of the present invention.

[0061] The third and fourth embodiments may be combined. That is, in the wetting step S31, the photovoltaic module 100 may be wetted with a potassium iodide solution or ethanol, and in the separation step S2, the pulverized materials may be rubbed together in a potassium iodide solution or ethanol. In this case, the types of solutions may be different between the wetting step S31 and the separation step S2. Specifically, in the wetting step S31, the photovoltaic module 100 may be wetted with a potassium iodide solution, and in the separation step S2, the pulverized materials may be rubbed together in ethanol. Alternatively, in the wetting step S31, the photovoltaic module 100 may be wetted with ethanol, and in the separation step S2, the pulverized materials may be rubbed together in a potassium iodide solution.

[0062] The third embodiment and the fifth embodiment may be combined. That is, in the wetting step S31, the photovoltaic module 100 may be wetted with a potassium iodide solution or ethanol, and in the crushing step S1, the photovoltaic module 100 may be crushed in a potassium iodide solution or ethanol. In this case, the types of solutions may be different between the wetting step S31 and the crushing step S1. Specifically, in the wetting step S31, the photovoltaic module 100 may be wetted with a potassium iodide solution, and in the crushing step S1, the photovoltaic module 100 may be crushed in ethanol. Alternatively, in the wetting step S31, the photovoltaic module 100 may be wetted with ethanol, and in the crushing step S1, the photovoltaic module 100 may be crushed in a potassium iodide solution.

[0063] The fourth embodiment and the fifth embodiment may be combined. That is, in the pulverization step S1, the photovoltaic module 100 may be pulverized in a potassium iodide solution or in ethanol, and in the separation step S2, the pulverized materials may be rubbed together in a potassium iodide solution or in ethanol. In this case, the types of solutions may be different between the pulverization step S1 and the separation step S2. Specifically, in the pulverization step S1, the photovoltaic module 100 may be pulverized in a potassium iodide solution, and in the separation step S2, the pulverized materials may be rubbed together in ethanol. Alternatively, in the pulverization step S1, the photovoltaic module 100 may be pulverized in ethanol, and in the separation step S2, the pulverized materials may be rubbed together in a potassium iodide solution.

[0064] Alternatively, in the separation step S2, the pulverized material may be placed in a stripper solution and rubbed against itself. The use of the stripper solution allows the stripper solution to penetrate the sealant 20, causing it to swell. As a result, the light-transmitting sheet 40 is peeled off from the sealant 20. Peeling due to penetration of the stripper solution is thought to be due to reactive diffusion, which involves repeated swelling and interfacial peeling. Specifically, the sealant 20 swells and changes in volume due to the stripper solution, while the light-transmitting sheet 40 does not swell or change in volume. This is thought to result in shear stress occurring between the sealant 20 and the light-transmitting sheet 40, leading to peeling. It is more preferable to use ultrasonic vibration in a high-temperature stripper solution bath, which can further shorten the peeling time of the sealant 20 in the high-temperature liquid. Ultrasonic vibration may be used in one cycle or in combination of two or more cycles.

[0065] A neutral release agent containing a hydrocarbon solvent can be used as the release agent solution. In the photovoltaic module 100, a material that has good optical transparency, weather resistance, moisture resistance, and adhesive properties, as well as good mechanical properties and electrical properties such as electrical insulation and voltage resistance, is used as the encapsulant 20. For example, ethylene-vinyl acetate copolymer (EVA) and polyvinyl butyral (PVB) are often used, but these resins are cross-linked and firmly fixed to protect the photovoltaic cells, making it very difficult to separate the light-transmitting sheet 40 from the encapsulant 20. However, by using a neutral release agent containing a hydrocarbon solvent, the release agent can penetrate into the encapsulant and swell the resin components, making it easy to peel the light-transmitting sheet 40 from the encapsulant 20.

[0066] The neutral release agent preferably contains primarily a hydrocarbon solvent or an acetate solvent. Examples of the hydrocarbon solvent include linear hydrocarbons having 5 or more carbon atoms, such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, and hexadecane; branched hydrocarbons having 5 or more carbon atoms, such as isopentane, isohexane, isoheptane, isooctane, isononane, isodecane, isoundecane, isododecane, isododecane, isotridecane, isotetradecane, isopentadecane, and isohexadecane; and α-olefins having 5 or more carbon atoms, such as 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. More preferred are isohexane, isopentane, isododecane, isotridecane, 1-hexene, 1-octene, 1-dodecene, and 1-tetradecene.The content of the hydrocarbon solvent in the neutral release agent is preferably 10 to 70% by weight, more preferably 20 to 70% by weight.

[0067] Examples of acetate solvents include 3-methoxy-3-methyl-1-butyl acetate, dipropylene glycol methyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, and propylene glycol diacetate. Preferred examples include 3-methoxy-3-methyl-1-butyl acetate and dipropylene glycol methyl ether acetate. The content of the acetate solvent in the neutral release agent is preferably 5 to 20 wt %, more preferably 7 to 15 wt %.

[0068] The neutral release agent preferably uses a surfactant, glycol-based solvent, or alcohol-based solvent as a solubilizing agent, and can be made into a release agent with no flash point by solubilizing the hydrocarbon solvent in water. The content of the solubilizing agent in the neutral release agent is preferably 5 to 20 wt %, more preferably 7 to 15 wt %. A penetrating agent may also be added to improve penetration. The surfactant may be any of anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants, with nonionic surfactants being preferred. The content of the surfactant in the neutral release agent is preferably 5 to 20 wt %, more preferably 7 to 15 wt %.

[0069] The glycol-based solvent is selected from aliphatic glycols and aromatic glycols. Examples of aliphatic glycols include ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, methyl diglycol, methyl triglycol, isopropyl diglycol, butyl diglycol, hexyl glycol, hexyl diglycol, 2-ethylhexyl glycol, and 2-ethylhexyl diglycol. Examples of aromatic glycols include benzyl glycol, benzyl diglycol, benzyl triglycol, phenyl glycol, and phenyl diglycol. At least one of these is contained, but two or more may be used in combination. The content of the glycol-based solvent in the neutral release agent is preferably 0.1 to 10 wt %, more preferably 1 to 5 wt %.

[0070] Examples of alcohol-based solvents include monohydric alcohol-based solvents, selected from aliphatic alcohols and aromatic alcohols. Examples of aliphatic alcohols include methyl alcohol, ethyl alcohol, isopropyl alcohol, and butyl alcohol, while examples of aromatic alcohols include benzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, and phenoxyethanol. Of these, aromatic alcohols selected from benzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, and phenoxyethanol are preferred. Benzyl alcohol and phenoxyethanol are particularly preferred. The content of the alcohol-based solvent is preferably 0.1 to 5% by weight, more preferably 1 to 5% by weight.

[0071] Examples of penetrating agents include acetylene-based surfactants, ethylene oxide-added nonionic surfactants, and alkylsulfonic acid-based anionic surfactants, with acetylene-based surfactants being preferred. At least one of these surfactants should be included, but two or more may be used in combination. The content of the penetrating agent is preferably 0.1 to 5 wt %, more preferably 0.1 to 3 wt %.

[0072] Water can be contained as a neutral release agent. The water may be tap water, distilled water, ion-exchanged water, pure water, or the like. The water constituting the neutral release agent of the present invention is used to dissolve the surfactant component, and can be added in an amount that is the remainder after adding the hydrocarbon solvent, acetate solvent, glycol solvent, alcohol solvent, surfactant, penetrant, or the like. Since the neutral release agent of the present invention contains water as a component, it can also be called a quasi-aqueous release agent.

[0073] A preferred neutral release agent contains 10 to 70% by weight of 1-dodecene or 1-tetradecene as a hydrocarbon solvent, 5 to 20% by weight of 3-methoxy-3-methyl-1-butyl acetate or dipropylene glycol methyl ether acetate as an acetate solvent, 5 to 20% by weight of 2-ethylhexyl diglycol, a nonionic surfactant, benzyl alcohol or phenoxyethanol as a solubilizing agent, 0.1 to 5% by weight of an acetylene surfactant as a penetrating agent, and the remainder is water.

[0074] Furthermore, by using a stripping agent solution in the separation step S2, the stripping agent is allowed to penetrate into the crushed material in which the fragments of the sealing material 20 and the fragments of the solar cell 10 are integrated, and the fragments of the sealing material 20 and the fragments of the solar cell 10 are peeled off, and the fragments of the sealing material 20 and the fragments of the solar cell 10 can be separated in the stripping agent solution based on the difference in their respective specific gravities.

[0075] An alkaline stripper can be preferably used as the stripper solution for removing the fragments of the sealant 20 and the fragments of the photovoltaic cells 10. More preferably, an alkaline stripper containing a propylene glycol-based solvent and / or a dialkyl glycol-based solvent can be used. The alkaline stripper can penetrate into the interface between the sealant 20 and the photovoltaic cells 10 and remove the sealant 20 from the photovoltaic cells 10. Furthermore, by stirring the stripper solution in the stripper solution, the sealant 20 floats to the upper layer in the stripper solution due to the difference in specific gravity, and the photovoltaic cells 10 containing silicon sink to the lower layer in the stripper solution.

[0076] Any alkaline stripper can be used, but it is more preferable to use a stripper made alkaline by adding an amine solvent to a propylene glycol solvent and / or a dialkyl glycol solvent. Furthermore, the alkaline stripper may contain a hydrocarbon solvent, a surfactant, and water. A water-based alkaline stripper is more preferable because it is a safe stripper for this recycling process.

[0077] Examples of propylene glycol-based solvents as alkaline stripping agents include methyl propylene glycol, methyl propylene diglycol, methyl propylene triglycol, propyl propylene glycol, propyl propylene diglycol, butyl propylene glycol, butyl propylene diglycol, butyl propylene triglycol, phenyl propylene glycol, and methyl propylene glycol acetate, and among these, methyl propylene glycol, methyl propylene diglycol, and methyl propylene triglycol are preferred.

[0078] Examples of dialkyl glycol solvents as alkaline stripping agents include dimethyl glycol, dimethyl diglycol, dimethyl triglycol, diethyl diglycol, dibutyl diglycol, and dimethyl propylene diglycol, with diethyl diglycol and dimethyl propylene diglycol being preferred.

[0079] Amine solvents as alkaline strippers include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, dipropanolamine, tripropanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-(β-aminoethyl)ethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-ethyldiethanolamine, Nn-butylethanolamine, Nn-butyldiethanolamine, N- Examples include mono- to trialkanolamines such as (β-aminoethyl)isopropanolamine and N,N-diethylisopropanolamine; alicyclic amines such as 2-ethylhexylamine, cyclohexylamine, and dimethylaminocyclohexane; aromatic amines such as aniline and toluidine; dialkylamines such as diamylamine; N-methyl-2-pyrrolidone, dimethylformamide, and N,N-dimethylacetamide; and among these, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and dipropanolamine are preferred.

[0080] An example of an alkaline stripper is one that contains 20 to 60% by weight of a propylene glycol solvent, 10 to 35% by weight of a dialkyl glycol solvent, 5 to 15% by weight of an amine solvent, 1 to 10% by weight of a hydrocarbon solvent, 0.1 to 5% by weight of an acetylene penetrant, and the balance water. Among these, an alkaline stripper containing 30% by weight of dipropylene glycol methyl ether acetate, 49% by weight of methylpropylene triglyceride, 10% by weight of monoisopropanolamine, 5% by weight of 1-tetradecene, 1% by weight of an acetylene penetrant, and the balance water can be exemplified.

[0081] The neutral release agent and alkaline release agent of the present invention may contain various additives that are incorporated into conventional release agents, such as antioxidants, ultraviolet absorbers, viscosity modifiers, thickeners, colorants such as pigments, and fragrances, as needed. [Explanation of symbols]

[0082] 100··Photovoltaic Module 10. Solar cell 20. Sealing material 30 Back seat 40...Translucent sheet

Claims

1. A method for recovering resources from a photovoltaic module including: a photovoltaic cell having a perovskite structure; a resin sealing material that seals the photovoltaic cell; a back sheet that is provided on a back surface of the photovoltaic cell with the sealing material interposed therebetween; and a light-transmitting sheet that is provided on a front surface of the photovoltaic cell with the sealing material interposed therebetween, a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together; a separating step of rubbing the pulverized material produced in the pulverizing step together in a drum-type or cylindrical container by stirring or vibrating, thereby turning the photovoltaic cells in the pulverized material into a powder, and separating fragments of the encapsulant, fragments of the back sheet, and fragments of the light-transmitting sheet from one another, In the separation step, the pulverized material is introduced into a peptide solution, and the pulverized material is rubbed together in the peptide solution by stirring or vibration. Solar cell module resource recovery method.

2. A method for recovering resources from a photovoltaic module including: a photovoltaic cell having a perovskite structure; a resin sealing material that seals the photovoltaic cell; a back sheet that is provided on a back surface of the photovoltaic cell with the sealing material interposed therebetween; and a light-transmitting sheet that is provided on a front surface of the photovoltaic cell with the sealing material interposed therebetween, a wetting step of wetting the photovoltaic module in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated with each other, with a potassium iodide solution or ethanol; a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together after the wetting step; a separating step of rubbing the pulverized material produced in the pulverizing step together in a drum-type or cylindrical container by stirring or vibrating, thereby turning the photovoltaic cells in the pulverized material into a powder, and separating fragments of the encapsulant, fragments of the back sheet, and fragments of the light-transmitting sheet from one another in the pulverized material, Solar cell module resource recovery method.

3. A method for recovering resources from a photovoltaic module including: a photovoltaic cell having a perovskite structure; a resin sealing material that seals the photovoltaic cell; a back sheet that is provided on a back surface of the photovoltaic cell with the sealing material interposed therebetween; and a light-transmitting sheet that is provided on a front surface of the photovoltaic cell with the sealing material interposed therebetween, a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together; a separating step of rubbing the pulverized material produced in the pulverizing step together in a drum-type or cylindrical container by stirring or vibrating, thereby turning the photovoltaic cells in the pulverized material into a powder, and separating fragments of the encapsulant, fragments of the back sheet, and fragments of the light-transmitting sheet from one another, In the separation step, the pulverized materials are rubbed together in a potassium iodide solution or ethanol by stirring or vibration. Solar cell module resource recovery method.

4. A method for recovering resources from a photovoltaic module including: a photovoltaic cell having a perovskite structure; a resin sealing material that seals the photovoltaic cell; a back sheet that is provided on a back surface of the photovoltaic cell with the sealing material interposed therebetween; and a light-transmitting sheet that is provided on a front surface of the photovoltaic cell with the sealing material interposed therebetween, a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together; a separating step of rubbing the pulverized material produced in the pulverizing step together in a drum-type or cylindrical container by stirring or vibrating, thereby turning the photovoltaic cells in the pulverized material into a powder, and separating fragments of the encapsulant, fragments of the back sheet, and fragments of the light-transmitting sheet from one another, In the crushing step, the photovoltaic module is crushed in a potassium iodide solution or ethanol. Solar cell module resource recovery method.

5. A method for recovering resources from a photovoltaic module including: a photovoltaic cell having a perovskite structure; a resin sealing material that seals the photovoltaic cell; a back sheet that is provided on a back surface of the photovoltaic cell with the sealing material interposed therebetween; and a light-transmitting sheet that is provided on a front surface of the photovoltaic cell with the sealing material interposed therebetween, a crushing step of crushing the photovoltaic module in a state in which the photovoltaic cells, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together; a separating step in which the pulverized material produced in the pulverizing step is rubbed together in a drum-shaped or cylindrical container by stirring or vibrating, thereby turning the photovoltaic cells in the pulverized material into a powder, and separating the fragments of the encapsulant, the fragments of the back sheet, and the fragments of the light-transmitting sheet in the pulverized material from one another; The method further comprises a precipitation step of introducing the powdered photovoltaic cell, the fragments of the encapsulant, the fragments of the back sheet, and the fragments of the light-transmitting sheet obtained in the separation step into a peptide solution and precipitating them. Solar cell module resource recovery method.

Images