Solar cell module resource recovery method

Abstract

This provides a simpler method for recovering resources from solar cell modules. [Solution] The process includes a grinding step S1 in which the solar cell module 100, comprising a perovskite structure solar cell 10, a encapsulant 20, a backsheet 30, and a light-transmitting sheet 40 integrated together, is ground up; and a separation step S2 in which the pulverized material generated in the grinding step is rubbed together to turn the solar cell 10 in the pulverized material into powder and separate the fragments of the encapsulant 20, the backsheet 30, and the light-transmitting sheet 40 from each other, wherein in the separation step S2 the pulverized material is added to a peptide solution and stirred.

Description

Technical Field

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

Background Art

[0002] Photovoltaic cells generate electricity using clean energy such as sunlight, and thus are considered effective in reducing the environmental load. A photovoltaic module included in a photovoltaic cell includes a photovoltaic cell that realizes photoelectric conversion, a sealing material that seals the photovoltaic cell, a glass substrate that protects the front surface of the photovoltaic cell, and a backsheet that protects the back surface of the photovoltaic cell. The photovoltaic module needs to be replaced due to aging deterioration, reduction of light transmittance, deterioration of mechanical properties, etc. caused by use in a harsh environment exposed to sunlight. However, it is required to recover valuable resources from the deteriorated photovoltaic module and reuse them.

[0003] Patent Document 1 discloses a method for separating a photovoltaic module into each material. In this method, first, a pre-step of mechanically peeling the backsheet from the photovoltaic module is performed, and a separation step of immersing the photovoltaic module from which the backsheet has been peeled in a stripping agent solution to separate the glass substrate from the photovoltaic module is performed. Then, a step of separating and recovering the sealing material and the photovoltaic cell is performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the method described in Patent Document 1, a step of mechanically peeling only the backsheet from the photovoltaic module is required, which is laborious.

[0006] Therefore, the present invention aims to provide a method for more easily recovering resources from solar cell modules. [Means for solving the problem]

[0007] The present invention relates to a method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, comprising: a grinding step of grinding the solar cell module in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a separation step of rubbing the pulverized material generated in the grinding step together to make the solar cell in the pulverized material into powder and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other, wherein in the separation step, the pulverized material is added to a peptide solution and stirred.

[0008] Furthermore, the present invention relates to a method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, comprising: a wetting step of moistening the solar cell module, in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated, with a potassium iodide solution or ethanol; a grinding step of grinding the solar cell module, in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated, after the wetting step; and a separation step of rubbing the pulverized material produced in the grinding step together to turn the solar cell in the pulverized material into powder and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other.

[0009] Furthermore, the present invention relates to a method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, the method comprising: a grinding step of grinding the solar cell module in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a separation step of rubbing the pulverized material generated in the grinding step together to make the solar cell in the pulverized material into powder and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other, wherein in the separation step the pulverized material is stirred in a potassium iodide solution or ethanol.

[0010] Furthermore, the present invention relates to a method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, comprising: a grinding step of grinding the solar cell module in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated; and a separation step of rubbing the pulverized material generated in the grinding step together to turn the solar cell in the pulverized material into powder and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other, wherein in the grinding step, the solar cell module is ground in a potassium iodide solution or ethanol.

[0011] Furthermore, the present invention relates to a method for recovering resources from a solar cell module comprising a solar cell having a perovskite structure, a resin sealing material for sealing the solar cell, a back sheet provided on the back of the solar cell via the sealing material, and a light-transmitting sheet provided on the front of the solar cell via the sealing material, the method further comprising: a grinding step of grinding the solar cell module in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated; a separation step of rubbing the pulverized material generated in the grinding step together to make the solar cell in the pulverized material into powder and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other; and a precipitation step of adding the powdered material of the solar cell, 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 into a peptide solution and allowing them to precipitate. [Effects of the Invention]

[0012] According to the present invention, a method for more easily recovering resources from solar cell modules can be provided. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view of a solar cell module used in an embodiment of the present invention. [Figure 2] This diagram shows the flow of a solar cell module resource recovery method according to the first embodiment of the present invention. [Figure 3] This diagram shows the flow of a solar cell module resource recovery method according to the third embodiment of the present invention. [Modes for carrying out the invention]

[0014] Hereinafter, a method for recovering resources from a solar cell module according to an embodiment of the present invention will be described with reference to the drawings.

[0015] <First Embodiment> First, a method for recovering resources from a solar cell module according to the 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 solar cell module 100 used in the first embodiment. As shown in Figure 1, the solar cell module 100 includes a solar cell cell 10 that realizes photoelectric conversion, a sealing material 20 that seals the solar cell cell 10, a back sheet 30 that protects the back of the solar cell cell 10, and a light-transmitting sheet 40 that protects the front of the solar cell cell 10.

[0016] The solar cell 10 has a perovskite structure. Specifically, the perovskite structure of the solar cell 10 contains organic groups such as methylammonium, metals such as lead, tin, and bismuth, and halogens such as iodine, bromine, and chlorine. A metal is located at the center of the crystal structure, and an octahedron is formed by six halogens surrounding this metal. Eight positive ions of organic matter are arranged on this octahedron to form a hexahedron, completing the perovskite structure. The chemical formula of a 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 with excellent transparency, flexibility, adhesion, tensile strength, and weather resistance, such as an ethylene-vinyl acetate copolymer (EVA) sheet or a polyvinyl butyral (PVB) sheet. In the solar cell module 100, the solar cell cells 10 are sandwiched between the encapsulant 20. The encapsulant 20 is adhesive and adheres to the back sheet 30 and the light-transmitting sheet 40.

[0018] The backsheet 30 is a resin sheet made by laminating, for example, a fluororesin or a polyester resin, and is provided on the back of the solar cell 10 via a sealing material 20. Since the backsheet 30 will be exposed to the outdoor environment, it is required to have weather resistance and moisture resistance.

[0019] The light-transmitting sheet 40 is made of glass and is provided on the front surface of the solar cell 10 via the sealing material 20. Similar to the backsheet 30, the light-transmitting sheet 40 is exposed to the outdoor environment, so weather resistance and moisture resistance are required. In addition, the light-transmitting sheet 40 is required to have transparency in order to transmit as much sunlight as possible. The light-transmitting sheet 40 is not limited to being made of glass and may be formed from a transparent resin.

[0020] This embodiment recovers valuable resources from the solar cell module 100. Valuable resources in the solar cell module 100 include, for example, halogens such as iodine (I), glass, and the like.

[0021] FIG. 2 is a diagram showing the flow of the solar cell module resource recovery method according to this embodiment. As shown in FIG. 2, the solar cell module resource recovery method includes a pulverization step S1, a separation step S2, a precipitation step S3, and a resource recovery step S4.

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

[0023] The pulverization is performed while the solar cell 10, the sealing material 20, the backsheet 30, and the light-transmitting sheet 40 are integrated. That is, in the pulverization step S1, a pulverized product in which fragments of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 are integrated is generated.

[0024] When the solar cell module 100 includes a frame (not shown) for assembling the solar cell 10, the sealing material 20, the backsheet 30, and the light-transmitting sheet 40, it is preferable to remove the frame from the solar cell module 100 before the pulverization step S1.

[0025] The frame is provided between the backsheet 30 and the translucent sheet 40. The frame is provided along the periphery of the backsheet 30 and the translucent sheet 40, protecting the periphery of the backsheet 30 and the translucent sheet 40, and is used to fix adjacent solar cell modules 100. The frame is a metal frame such as iron, stainless steel, or aluminum. From the viewpoint of lightness and thermal conductivity, it is more preferable for the frame to be made of aluminum.

[0026] In separation step S2, the pulverized material generated in grinding step S1 is rubbed together. As the pulverized material is rubbed together, the solar cell 10 in the pulverized material becomes powder, and the fragments of the sealing material 20, the back sheet 30, and the light-transmitting sheet 40 in the pulverized material are separated from each other.

[0027] The grinding of the materials may be done by agitation or by vibration. The vibration method includes ultrasonic vibration, etc. Ultrasonic vibration may be performed in one cycle or in combination of two or more cycles. Furthermore, the grinding of the materials may be performed in a drum-type container, a cylindrical container, or any other type of container.

[0028] In the precipitation step S3, the powdered material of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 obtained in the separation step S2 are added to the solution and allowed to precipitate. The powdered material of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 precipitate in order of decreasing 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 backsheet 30 is approximately 1.1 to 2.17 (for example, the specific gravity of fluororesin is approximately 2.12 to 2.17, and the specific gravity of polyester resin is approximately 1.1 to 1.4), and the specific gravity of the resin used in the sealing material 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 sedimentation step S3, the fragments of the light-transmitting sheet 40, the powdered material of the solar cell 10, the fragments of the back sheet 30, and the fragments of the sealing material 20 settle in that order, or in that order, the fragments of the light-transmitting sheet 40, the fragments of the back sheet 30, the powdered material of the solar cell 10, and the fragments of the sealing material 20 settle in that order.

[0030] The liquid may be water or a solution. A peptide solution, more specifically a nattokinase solution, can be used as the solution. Peptide solutions have the effect of promoting the precipitation of minute solid particles mixed in the solution. By using a peptide solution in the precipitation step S3, the time required for precipitation can be shortened, and thus the time required for resource recovery can be reduced.

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

[0032] In the precipitation step S3, instead of adding the powdered solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the translucent sheet 40 to the solution, the solution may be poured over the powdered solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the translucent sheet 40. Alternatively, in the separation step S2, the pulverized materials may be rubbed together while the liquid is poured over them.

[0033] In the resource recovery process S4, fragments of the translucent sheet 40, powdered material of the solar cell 10, fragments of the back sheet 30, and fragments of the sealing material 20 that have settled in the sedimentation process S3 are recovered. Specifically, fragments of the translucent sheet 40 (glass pellets) are recovered when they have settled in the liquid, powdered material of the solar cell 10 is recovered when it has settled, fragments of the back sheet 30 are recovered when they have settled, and fragments of the sealing material 20 are recovered when they have settled. The solution after the sedimentation is recovered can be reused in the sedimentation process S3.

[0034] Well-known technologies can be used for resource recovery. For example, a specific gravity separation method may be used, a separation method utilizing melting point may be used, or a separation method using magnetic force may be used.

[0035] In this embodiment, the crushed materials are rubbed together to pulverize the solar cell cells 10 in the crushed material, and the fragments of the sealing material 20, backsheet 30, and light-transmitting sheet 40 in the crushed material are separated from each other. Therefore, the step of peeling only the backsheet 30 from the sealing material 20 is unnecessary. Consequently, labor is reduced and resources can be easily recovered.

[0036] <Second Embodiment> Next, a method for recovering resources from a solar cell module according to a second embodiment of the present invention will be described. In the following, the differences from the first embodiment will be mainly described, and for configurations that are the same as or equivalent to those described in the first embodiment, the same reference numerals as in the first embodiment will be used in the figures and their descriptions will be omitted.

[0037] The solar cell module resource recovery method according to this embodiment includes a crushing step S1, a separation step S2, a sedimentation step S3, and a resource recovery step S4, similar to the first embodiment.

[0038] In the first embodiment, the separation step S2 is dry, but in this embodiment, the separation step S2 is wet. Specifically, in this embodiment, the pulverized material generated in the grinding step S1 is added to a liquid and rubbed together in the liquid. The rubbing of the pulverized material together may be done by stirring or by vibration. Furthermore, the rubbing of the pulverized material together may be done in a drum-type container, a cylindrical container, or any other container.

[0039] The liquid may be water or a solution. A peptide solution, more specifically a nattokinase solution, can be used as the solution. A citric acid aqueous solution and a chitosan aqueous solution may also be used as the solution.

[0040] In the first embodiment, the precipitation step S3 involves adding the powdered material of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 separated in the separation step S2 to a liquid and allowing them to settle. In this embodiment, the powdered material of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 are settled by stopping the stirring or vibration in the separation step S2. If a peptide solution is used in the separation step S2, the time required for precipitation can be shortened, and the time for resource recovery can be shortened.

[0041] In this embodiment, the pulverized materials are rubbed together in a liquid to turn the solar cell cells 10 into powder, and the fragments of the sealing material 20, backsheet 30, and translucent sheet 40 in the pulverized materials are separated from each other. As a result, the step of peeling only the backsheet 30 from the sealing material 20 is eliminated, as is the step of putting the powdered solar cell cells 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the translucent sheet 40 into the liquid. Consequently, the amount of work is reduced, and resources can be recovered more easily.

[0042] <Third Embodiment> Next, a method for recovering resources from a solar cell module according to the third embodiment of the present invention will be described. In the following, the differences from the first and second embodiments will be mainly described, and for configurations that are the same as or equivalent to those described in the first and second embodiments, the same reference numerals as in the first and second embodiments will be used in the figures, and their descriptions will be omitted.

[0043] Figure 3 is a diagram showing the flow of the solar cell module resource recovery method according to this embodiment. As shown in Figure 3, the solar cell 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 solar cell module 100 is moistened in a potassium iodide solution or with ethanol. The solar cell module 100 may be moistened by immersing it in a potassium iodide solution or ethanol, or by pouring a potassium iodide solution or ethanol over the solar cell module 100. By immersing the solar cell module 100 in a potassium iodide solution or ethanol, or by pouring a potassium iodide solution or ethanol over the solar cell module 100, the iodine contained in the perovskite structure is leached into the potassium iodide solution or ethanol. Therefore, separation and recovery of iodine becomes possible. The iodine is recovered by adding hydrogen peroxide to the solution in which the iodine has been leached.

[0045] In the wetting step S31, the solar cell module 100 is moistened with potassium iodide solution or ethanol, and then the solar cell module 100 is pulverized (pulverization step S1). At the time of pulverization of the solar cell module 100, the solar cell module may be wet or dry.

[0046] Since the steps from separation step S2 onward are almost the same as those in the first and second embodiments, their explanation will be omitted here.

[0047] In this embodiment, separating iodine, which is a heavy structural material in the perovskite structure, facilitates the recovery of other rare 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 moistened with potassium iodide solution or ethanol before the separation step S2 and 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 method for recovering resources from a solar cell module according to the fourth embodiment of the present invention will be described. In the following, the differences from the third embodiment will be mainly described, and for configurations that are the same as or equivalent to those described in the first to third embodiments, the same reference numerals as in the first to third embodiments will be used in the figures, and their descriptions will be omitted.

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

[0050] In this embodiment, the pulverized material generated by crushing the solar cell 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 rubbing of the pulverized material together may be done by stirring or by vibration. Furthermore, the rubbing of the pulverized material together may be done in a drum-type container, a cylindrical container, or any other type of container.

[0051] In this embodiment, by stopping the stirring or vibration in the separation step S2, the powdered material of the solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 settle. Therefore, the fragments of the light-transmitting sheet 40, the powdered material of the solar cell 10, fragments of the backsheet 30, and fragments of the sealing material 20 can be recovered.

[0052] Furthermore, during stirring or vibration in separation step S2, and after the stirring or vibration stops, iodine contained in the perovskite structure elutes into potassium iodide solution or ethanol. Therefore, iodine can be separated and recovered. The iodine is recovered by adding hydrogen peroxide to the solution in which the iodine has eluted.

[0053] In separation step S2, instead of immersing the solar cell module 100 in potassium iodide solution or ethanol, the powdered solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40 may be poured over the powdered solar cell 10, fragments of the sealing material 20, fragments of the backsheet 30, and fragments of the light-transmitting sheet 40. Alternatively, in separation step S2, the pulverized materials may be rubbed together while being poured over them in potassium iodide solution or ethanol.

[0054] The steps from the precipitation step S3 onward are almost the same as those in the first and second embodiments, so their explanation is omitted here.

[0055] <Fifth Embodiment> Next, a solar cell module resource recovery method according to the fifth embodiment of the present invention will be described. In the following, the differences from the third and fourth embodiments will be mainly described, and for configurations that are the same as or equivalent to those described in the first to fourth embodiments, the same reference numerals as in the first to fourth embodiments will be used in the figures and their descriptions will be omitted.

[0056] In the third embodiment, the solar cell module 100 is moistened with potassium iodide solution or ethanol and then pulverized. In the fourth embodiment, after pulverizing the solar cell module 100, the pulverized material is placed in potassium iodide solution or ethanol.

[0057] In this embodiment, the solar cell module 100 is placed in a potassium iodide solution or ethanol and then pulverized. In other words, in pulverization step S1, the solar cell module 100 is pulverized in a potassium iodide solution or ethanol. By pulverizing the solar cell module 100 in a potassium iodide solution or ethanol, the iodine contained in the perovskite structure is eluted into the potassium iodide solution or ethanol. Therefore, separation and recovery of iodine becomes possible. The iodine is recovered by adding hydrogen peroxide to the solution in which the iodine has been eluted.

[0058] In the grinding step S1, instead of immersing the solar cell module 100 in potassium iodide solution or ethanol, the solar cell module 100 may be ground while the potassium iodide solution or ethanol is applied to it. By recovering the potassium iodide solution or ethanol applied to the solar cell module 100, iodine can be separated and recovered.

[0059] Since the steps from separation step S2 onward are almost the same as those in the first and second embodiments, their explanation will be omitted here.

[0060] Although this embodiment has been described above, it goes without saying that the present invention is not limited to this embodiment. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally 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 solar cell module 100 may be moistened with potassium iodide solution or ethanol, and in the separation step S2, the pulverized materials may be rubbed together in potassium iodide solution or ethanol. In this case, the type of solution may be changed between the wetting step S31 and the separation step S2. Specifically, in the wetting step S31, the solar cell module 100 may be moistened with 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 solar cell module 100 may be moistened with ethanol, and in the separation step S2, the pulverized materials may be rubbed together in potassium iodide solution.

[0062] The third and fifth embodiments may be combined. That is, in the wetting step S31, the solar cell module 100 may be moistened with potassium iodide solution or ethanol, and in the grinding step S1, the solar cell module 100 may be ground in potassium iodide solution or ethanol. In this case, the type of solution may be changed between the wetting step S31 and the grinding step S1. Specifically, in the wetting step S31, the solar cell module 100 may be moistened with potassium iodide solution, and in the grinding step S1, the solar cell module 100 may be ground in ethanol. Alternatively, in the wetting step S31, the solar cell module 100 may be moistened with ethanol, and in the grinding step S1, the solar cell module 100 may be ground in potassium iodide solution.

[0063] The fourth and fifth embodiments may be combined. That is, in the grinding step S1, the solar cell module 100 may be ground in a potassium iodide solution or ethanol, and in the separation step S2, the ground material may be rubbed together in a potassium iodide solution or ethanol. In this case, the type of solution may be changed between the grinding step S1 and the separation step S2. Specifically, in the grinding step S1, the solar cell module 100 may be ground in a potassium iodide solution, and in the separation step S2, the ground material may be rubbed together in ethanol. Alternatively, in the grinding step S1, the solar cell module 100 may be ground in ethanol, and in the separation step S2, the ground material may be rubbed together in a potassium iodide solution.

[0064] Furthermore, in separation step S2, the pulverized material may be added to the release agent solution and rubbed together. By using the release agent solution, the release agent solution penetrates the sealant 20 and the sealant 20 swells. As a result, the translucent sheet 40 is peeled off from the sealant 20. The peeling due to the penetration of the release agent solution is thought to be due to reaction diffusion, which involves repeated swelling and interfacial peeling. Specifically, the sealant 20 swells and undergoes a volume change due to the release agent solution, while the translucent sheet 40 does not swell or undergo a volume change. Therefore, shear stress is generated between the sealant 20 and the translucent sheet 40, leading to peeling. It is more preferable to use ultrasonic vibration in combination in a high-temperature release agent solution bath, which further shortens 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] As the release agent solution, a neutral release agent containing a hydrocarbon solvent can be used. In the solar cell module 100, the encapsulant 20 is made of a material that has good light transmittance, weather resistance, moisture resistance, and adhesion, as well as good mechanical properties, electrical insulation, and dielectric strength. For example, ethylene-vinyl acetate copolymer (EVA) and polyvinyl butyral (PVB) are often used, but these resins are crosslinked and firmly fixed to protect the solar cell, 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, it is possible to penetrate into the encapsulant and swell the resin components, allowing the light-transmitting sheet 40 to be easily peeled off from the encapsulant 20.

[0066] The neutral release agent preferably contains mainly hydrocarbon solvents and acetate solvents. Examples of hydrocarbon solvents include any straight-chain hydrocarbon having 5 or more carbon atoms, such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, and hexadecane; any branched hydrocarbon having 5 or more carbon atoms, such as isopentane, isohexane, isoheptane, isooctane, isononane, isodecane, isounddecane, isododecane, isounddecane, 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-hexadecane, and 1-octadecene. More preferably, isohexane, isopentane, isododecane, isotridecane, 1-hexene, 1-octene, 1-dodecene, and 1-tetradecene. The content of hydrocarbon solvents in the neutral stripping agent is preferably 10 to 70% by weight, more preferably 20 to 70% by weight.

[0067] Examples of acetate-based 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. Preferably, 3-methoxy-3-methyl-1-butyl acetate and dipropylene glycol methyl ether acetate are examples. The content of the acetate-based solvent in the neutral release agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight.

[0068] Neutral stripping agents can be made into stripping agents with no flash point by using surfactants, glycol-based solvents, or alcohol-based solvents as solubilizers to solubilize hydrocarbon solvents in water. The content of the solubilizer in the neutral stripping agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight. Penetrating agents may also be added to improve penetration. Any of anionic surfactants, cationic surfactants, nonionic surfactants, or amphoteric surfactants can be included as surfactants, but nonionic surfactants are preferred. The content of the surfactant in the neutral stripping agent is preferably 5 to 20% by weight, more preferably 7 to 15% by weight.

[0069] Furthermore, 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 included, but two or more may be used in combination. The content of the glycol-based solvent in the neutral stripping agent is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight.

[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. Among these, it is preferable to select from benzyl alcohol, 4-methylbenzyl alcohol, 2-ethylbenzyl alcohol, and phenoxyethanol as aromatic alcohols. 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-additive type nonionic surfactants, and alkyl sulfonic acid-based anionic surfactants, with acetylene-based surfactants being preferred. At least one of these is included, but two or more may be used in combination. The content of the penetrating agent is preferably 0.1 to 5% by weight, more preferably 0.1 to 3% by weight.

[0072] The neutral stripping agent can contain water. The water can be tap water, distilled water, deionized water, or pure water. The water in the neutral stripping agent of this invention is for dissolving the surfactant components, and the remaining amount after adding hydrocarbon solvents, acetate solvents, glycol solvents, alcohol solvents, surfactants, penetrating agents, etc., can be added. Since the neutral stripping agent of this invention contains water as a component, it can also be called a semi-aqueous stripping agent.

[0073] A preferred neutral stripping agent may contain 10-70% by weight of 1-dodecene or 1-tetradecene as a hydrocarbon solvent, 5-20% by weight of 3-methoxy-3-methyl-1-butyl acetate or dipropylene glycol methyl ether acetate as an acetate solvent, 5-20% by weight of a combination of 2-ethylhexyl diglycol, a nonionic surfactant, benzyl alcohol, or phenoxyethanol as a solubilizer, and 0.1-5% by weight of an acetylene-based surfactant as a penetrating agent, with the remainder being water.

[0074] Furthermore, by using a release agent solution in the separation step S2, the release agent is permeated into the pulverized material in which fragments of the sealing material 20 and fragments of the solar cell 10 are integrated, separating the fragments of the sealing material 20 and the fragments of the solar cell 10. Based on the difference in specific gravity between them, the fragments of the sealing material 20 and the fragments of the solar cell 10 can be separated in the release agent solution.

[0075] Preferably, an alkaline release agent can be used as the release agent solution for separating the fragments of the encapsulant 20 and the fragments of the solar cell 10. More preferably, an alkaline release agent containing a propylene glycol-based solvent and / or a dialkyl glycol-based solvent can be used. The alkaline release agent penetrates the interface between the encapsulant 20 and the solar cell 10, allowing the encapsulant 20 to be separated from the solar cell 10. Furthermore, by stirring the release agent solution, the encapsulant 20 floats to the upper layer of the release agent solution due to the difference in specific gravity, while the silicon-containing solar cell 10 sinks to the lower layer of the release agent solution.

[0076] Any alkaline stripping agent can be used, but more preferably, a stripping agent made alkaline by adding an amine-based solvent to a propylene glycol-based solvent and / or a dialkyl glycol-based solvent can be used. Furthermore, the alkaline stripping agent may contain a hydrocarbon-based solvent, a surfactant, and water. Using a water-based alkaline stripping agent is preferable as it makes the stripping agent safer in this recycling process.

[0077] Examples of propylene glycol-based solvents used as alkaline stripping agents include methylpropylene glycol, methylpropylene diglycol, methylpropylene triglycol, propylpropylene glycol, propylpropylene diglycol, butylpropylene glycol, butylpropylene diglycol, butylpropylene triglycol, phenylpropylene glycol, and methylpropylene glycol acetate, among which methylpropylene glycol, methylpropylene diglycol, and methylpropylene triglycol are preferred.

[0078] Examples of dialkyl glycol-based solvents used 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-based solvents used as alkaline stripping agents include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, dipropanolamine, trippropanolamine, 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-trial canolamines 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, among which monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and dipropanolamine are preferred.

[0080] Examples of alkaline stripping agents include 20-60% by weight of a propylene glycol-based solvent, 10-35% by weight of a dialkyl glycol-based solvent, 5-15% by weight of an amine-based solvent, 1-10% by weight of a hydrocarbon-based solvent, 0.1-5% of an acetylene-based penetrant, and the remainder being water. In particular, an example of an alkaline stripping agent is provided, consisting of 30% by weight of dipropylene glycol methyl ether acetate, 49% by weight of methyl propylene glycol, 10% by weight of monoisopropanolamine, 5% by weight of 1-tetradecene, 1% of an acetylene-based penetrant, and the remainder being water.

[0081] The neutral and alkaline release agents in the present invention may, as needed, contain various additives commonly found in conventional release agents, such as antioxidants, UV absorbers, viscosity modifiers, thickeners, colorants such as pigments, and fragrances. [Explanation of Symbols]

[0082] 100 solar cell modules 10...Solar cell 20.. Sealing material 30...back seat 40...Translucent Sheet

Claims

1. A method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, A grinding step in which the solar cell, the encapsulant, the back sheet, and the light-transmitting sheet are integrated and the solar cell module is ground up, The process includes a separation step in which the pulverized material produced in the pulverization step is rubbed together to turn the solar cell in the pulverized material into powder, and separates the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other. In the separation step, the pulverized material is added to the peptide solution and stirred. Methods for recovering resources from solar cell modules.

2. A method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, A wetting step in which the solar cell module, in which the solar cell, the sealing material, the back sheet, and the light-transmitting sheet are integrated, is moistened with a potassium iodide solution or ethanol, After the wetting step, a grinding step is performed to grind the solar cell module in which the solar cell, the encapsulant, the back sheet, and the light-transmitting sheet are integrated together. The process includes a separation step in which the pulverized material produced in the pulverization step is rubbed together to turn the solar cell in the pulverized material into powder, and to separate the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other. Methods for recovering resources from solar cell modules.

3. A method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, A grinding step in which the solar cell, the encapsulant, the back sheet, and the light-transmitting sheet are integrated and the solar cell module is ground up, The process includes a separation step in which the pulverized material produced in the pulverization step is rubbed together to turn the solar cell in the pulverized material into powder, and separates the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other. In the separation step, the pulverized material is stirred in a potassium iodide solution or ethanol. Methods for recovering resources from solar cell modules.

4. A method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, A grinding step in which the solar cell, the encapsulant, the back sheet, and the light-transmitting sheet are integrated and the solar cell module is ground up, The process includes a separation step in which the pulverized material produced in the pulverization step is rubbed together to turn the solar cell in the pulverized material into powder, and separates the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet from each other. In the aforementioned crushing step, the solar cell module is crushed in a potassium iodide solution or ethanol. Methods for recovering resources from solar cell modules.

5. A method for recovering resources from a solar cell module comprising: a solar cell having a perovskite structure; a resin sealing material for sealing the solar cell; a back sheet provided on the back of the solar cell via the sealing material; and a light-transmitting sheet provided on the front of the solar cell via the sealing material, A grinding step in which the solar cell, the encapsulant, the back sheet, and the light-transmitting sheet are integrated and the solar cell module is ground up, A separation step is performed in which the pulverized material produced in the pulverization step is rubbed together to turn the solar cell in the pulverized material into powder, and the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet in the pulverized material are separated from each other. The method further comprises a precipitation step in which the powdered material of the solar cell obtained in the separation step, the fragments of the sealing material, the fragments of the back sheet, and the fragments of the light-transmitting sheet are added to a peptide solution and precipitated. Methods for recovering resources from solar cell modules.

Images