JP2014094321A - Method of disintegrating solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate and recover constituent members of solar cell modules, including non-standard solar cell modules produced in e.g. production processes and used solar cell modules, by using an easy-to-handle organic solvent having small environmental load.SOLUTION: A method of disintegrating a solar cell module composed of a solar cell, a sealant, a back surface material and/or glass by immersing the solar cell module in a solvent containing one or more organic solvents selected from those of a chemical structure of formula (1), where R, R, Rand Rare 1-8C hydrocarbon groups, and R, Rand Rare hydrogen and/or 1-8C hydrocarbon groups.

Description

  The present invention relates to a method for dismantling a solar cell module.

  Recently, new energy technology using natural energy has attracted attention because of concern for global environmental problems. As one of them, technology using solar energy has attracted attention, and the production amount of solar cells has been rapidly increasing in recent years. As a result, there is a concern that the amount of out-of-specification solar cell modules generated in the manufacturing process and the like, and the waste of used solar cells will increase. For this reason, it is thought that the needs to collect | recover each member which comprises a solar cell module in the form which can be reused will increase increasingly from now on.

  Usually, a solar cell module is a terminal for taking out electric power by sandwiching several solar cells with a sealing material such as ethylene-vinyl acetate copolymer (EVA) and attaching it to tempered glass, covering the back with a protective film. Etc. are manufactured by attaching a frame such as aluminum at the end. For this reason, in order to separate and recycle the members used in the solar cell module, it is necessary to remove EVA as a sealing material and separate the tempered glass and the solar cells.

  As a method of removing the sealing material, (1) a method of baking and removing the ethylene-vinyl acetate copolymer using a fluidized bed (see Non-Patent Document 1, for example), and (2) immersion in nitric acid. A method of decomposing and removing the ethylene-vinyl acetate copolymer (see Patent Document 1), and (3) a method of swelling or peeling the ethylene-vinyl acetate copolymer with an organic solvent such as trichloroethylene or toluene (for example, Non-Patent Document 2). And Patent Document 2). However, the method (1) has a problem that the surface of the solar cell is scraped off in the course of treatment and the recovered solar cell cannot be reused as it is. In the method (2), since strong acid nitric acid is used, it is dangerous during handling. In addition, a large amount of nitric acid waste liquid after use becomes a problem. In the method (3), the use of a halogen-based solvent increases the environmental load. On the other hand, toluene is highly volatile and has a flash point of 40 ° C. or lower, so it is a compound that ignites even at relatively low temperatures. Even in the normal working environment, if the vapor generated from these organic solvents is confused with air, the flash It is easy to cause a fire such as explosion or explosion and difficult to handle. Furthermore, since toluene has a neuropathy effect, it is necessary to avoid its use as much as possible, for example, the management concentration according to the work environment evaluation standard is set to 20 ppm or less.

JP 2004-186547 A JP 2007-180063 A

Results report on solar power generation common substrate technology development from NEDO, Solar and Wind Technology Development Office "Research and development of recycling and reuse processing technology of solar power generation system" Japan Solar Energy Society / Japan Energy Wind Association Joint Presentation (November 1998)

  Separating and recovering the components of solar cell modules from nonstandard solar cell modules generated during the manufacturing process, used solar cell modules, etc. using organic solvents that have a low environmental impact and are easy to handle With the goal.

  In the present invention, a solar battery module composed of a solar battery cell, a sealant, a back material, and glass is shown by any of the following chemical structures

(R _1, R _3, R _{4 and} R ₆ are hydrocarbon groups having 1 to 8 carbon atoms, and R ₂ , R ₅ and R ₇ are hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. .)
This is a method for disassembling a solar cell module immersed in a solution containing at least one organic solvent selected from organic solvents.

  According to the present invention, a solar cell module component that uses an organic solvent that has a low environmental impact and is easy to handle, such as a substandard solar cell module generated during a manufacturing process or a used solar cell module. Can be separated and recovered.

  Examples of solar cell modules that can be used in the present invention include conventionally known solar cell modules. For example, the solar cell is sandwiched between sealing materials and bonded to tempered glass. In order to use a solar battery module, which is an element that generates power by receiving light, as a solar power generator, the solar battery module is preferably sandwiched between sealing materials and bonded to tempered glass so that the solar battery module is attached. Forming. As for a solar cell module, Preferably, the back material is affixed on the other side of the tempered glass of a solar cell module.

  The member of the solar cell module concerning this invention is demonstrated concretely.

The solar battery cell is preferably formed by laminating a transparent electrode film, a photoelectric conversion layer, and a back electrode film in this order on the lower surface of the translucent glass substrate. Examples of the light-transmitting substrate include a heat resistant resin such as glass and polyimide. Examples of the transparent electrode film include SnO ₂ , ZnO, and ITO. Examples of the photoelectric conversion layer include silicon-based photoelectric conversion films such as amorphous silicon and microcrystalline silicon, and compound-based photoelectric conversion films such as CdTe and CuInSe ₂ . The back electrode film is made of, for example, a ZnO transparent electrode film and a silver thin film.

  As the tempered glass, soda lime glass is generally used, and highly transmissive glass (so-called white plate glass) is used. High transmission glass is soda lime glass with a low iron content, and has high light transmittance. Moreover, the template glass which formed the embossed pattern on the surface is also used.

  The sealing material may be any material that is transparent and has adhesiveness and flexibility, and preferably an ethylene-vinyl acetate copolymer, polyvinyl butyral, and polyurethane are generally used. At this time, a crosslinked resin is preferable from the viewpoint of strength and durability. Accordingly, the raw material for the sealing material is preferably a crosslinkable thermoplastic resin, particularly a resin that undergoes a crosslinking reaction when heated. The cross-linkable thermoplastic resin is not particularly limited as long as the cross-linking reaction proceeds when heated. For example, an ethylene-vinyl acetate copolymer can be cross-linked by blending a cross-linking material. If it is, it can bridge | crosslink by making an isocyanate group and a hydroxyl group react.

  The back material is usually a resin film or a multilayer film having at least one resin layer. As the resin used, a polyester resin typified by polyethylene terephthalate and a fluorine resin typified by polyvinylidene fluoride are generally used. In the case of a multilayer film, different types of resins may be laminated, or may be laminated with a metal foil typified by an aluminum foil. In general, a method is used in which both sides of an intermediate layer made of a biaxially stretched polyethylene terephthalate film or aluminum foil are sandwiched between fluorine resin layers having excellent weather resistance.

  The immersion in the organic solvent in the present invention is preferably performed after removing the aluminum frame, terminal box, etc. connected to the module from the solar cell. These removals can be performed manually, for example.

  The organic solvent used in the present invention is at least one organic solvent selected from organic solvents represented by the following structures.

R _{1 in the} above structural formula is a hydrocarbon group having 1 to 8 carbon atoms. R ₁ is preferably a hydrocarbon group having 1 to 6 carbon atoms. More preferably, it is a hydrocarbon group having 1 to 2 carbon atoms. R ₁ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, or a hexyl group. More preferred are a methyl group and an ethyl group.

R _{2 in the} above structural formula is hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. R ₂ is preferably hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. R ₂ is more preferably hydrogen or a hydrocarbon group having 1 to 3 carbon atoms. R ₂ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. More preferably, they are hydrogen or a methyl group, an ethyl group, and a propyl group.

R _{3 in the} above structural formula is a hydrocarbon group having 1 to 8 carbon atoms. R ₃ is preferably a hydrocarbon group having 1 to 6 carbon atoms. R ₃ is more preferably a hydrocarbon group having 1 to 3 carbon atoms. R ₃ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group. More preferred are a methyl group, an ethyl group, and a propyl group.

R _{4 in the} above structural formula is a hydrocarbon group having 1 to 8 carbon atoms. R ₄ is preferably a hydrocarbon group having 1 to 6 carbon atoms. R ₄ is more preferably a hydrocarbon group having 1 to 3 carbon atoms. R ₄ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. More preferred are a methyl group, an ethyl group, and a propyl group.

R _{5 in the} above structural formula is hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. R ₅ is preferably hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. R ₅ is more preferably hydrogen. R ₅ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group. More preferred is hydrogen.

R _{6 in the} above structural formula is a hydrocarbon group having 1 to 8 carbon atoms. R ₆ is preferably a hydrocarbon group having 1 to 6 carbon atoms. R ₆ is more preferably a hydrocarbon group having 1 to 3 carbon atoms. R ₆ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. More preferred are a methyl group, an ethyl group, and a propyl group.

R _{7 in the} above structural formula is a hydrocarbon group having 1 to 8 carbon atoms. R ₇ is preferably hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. R ₇ is more preferably hydrogen. A methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group and a hexyl group are preferred. More preferred is hydrogen.

  These organic solvents include methoxybenzene, ethoxybenzene, 1-isopropyl-4-methoxybenzene, dioxane, tetrahydrofuran, cyclopentyl methyl ether and other ethers, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclohexene, and other alicyclic rings. Preferred are hydrocarbons of the formula, aromatic hydrocarbons such as ethylbenzene, propylbenzene, isopropylbenzene, 1-butylbenzene, isobutylbenzene and 1-phenylpentane. More specifically, propylbenzene, isopropylbenzene, 1-butylbenzene, isobutylbenzene, 1-phenylpentane, methoxybenzene, ethoxybenzene, 1-isopropyl-4-methoxybenzene and the like are preferable. These organic solvents may be used alone or in combination.

  These organic solvents may be used by mixing with other organic solvents, and the content ratio of the organic solvent of the above structural formula is 50 to 100 wt%. Preferably, 70 to 100 wt%. More preferably, it is 80 to 100 wt%.

  In the method for disassembling a solar cell module of the present invention, the method of immersing in an organic solvent is, for example, a nonstandard solar cell module generated during a manufacturing process or the like, a used solar cell module, etc. at room temperature or under heating. And a method of immersing in an organic solvent.

  When immersed in an organic solvent under heating, for example, the solar cell module may be immersed in a heated organic solvent, or may be heated while being immersed in an organic solvent. There is no restriction on the heating source. The temperature is not limited as long as it does not exceed the boiling point of the solvent, but is preferably from 20 ° C to 110 ° C. More preferably, it is 20 ° C to 90 ° C.

  The immersion time varies depending on the immersion temperature and the size of the solar cell module, but is generally preferably 16 hours to 48 hours. More preferably, it is 16 hours to 36 hours.

  In the method for disassembling the solar cell module of the present invention, in order to increase the disassembly efficiency of the solar cell module, for example, an inert gas such as nitrogen is blown, the solution is stirred, the solar cell module itself rotates, and vibrations are applied. Auxiliary methods such as irradiation and cutting into the sealing material may be used alone or in combination.

1. Preparation of a simulated solar cell By removing the ethylene-vinyl acetate copolymer, which is a sealing material, the components used in the solar cell module can be separated and recycled, so an ethylene-vinyl acetate copolymer sheet Was sandwiched between a glass substrate (100 mm × 100 mm) and a back sheet, and a simulated solar cell module was produced by thermocompression bonding at 150 ° C. for 15 minutes using a laminator.

Example 1
The simulated solar cell module (100 mm × 100 mm) prepared above was placed in a glass immersion tank, and methoxybenzene was added so that the entire module was immersed. The dipping bath was heated to 90 ° C. and allowed to stand at this temperature for 24 hours. When the simulated solar cell module was taken out, the sealing material was peeled off and members such as tempered glass could be recovered.

Example 2
The same operation as in Example 1 was performed using isopropylbenzene in place of methoxybenzene in Example 1. As a result, the sealing material was peeled off in the same manner as in Example 1, and members such as tempered glass could be recovered.

Comparative Example 1
The same operation as in Example 1 was performed using N-methylpyrrolidone instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 2
The same operation as in Example 1 was performed using methyl isobutyl ketone instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 3
Acetone was used instead of methoxybenzene of Example 1, and the same operation as in Example 1 was performed. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 4
The same operation as in Example 1 was performed using cyclohexanone instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 5
The same operation as in Example 1 was performed using ethyl acetate instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 6
The same operation as in Example 1 was performed using ethylene glycol monomethyl ether acetate in place of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 7
1-butoxy-2-propanol was used instead of methoxybenzene in Example 1, and the same operation as in Example 1 was performed. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 8
Hexane was used instead of methoxybenzene of Example 1, and the same operation as in Example 1 was performed. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 9
The same operation as in Example 1 was performed using dodecane instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 10
The same operation as in Example 1 was carried out using N, N-dimethylformamide instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 11
The same operation as in Example 1 was performed using dimethyl sulfoxide instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

Comparative Example 12
The same operation as in Example 1 was carried out using γ-butyrolactone instead of methoxybenzene in Example 1. As a result, the sealing material was not peeled off and members such as tempered glass could not be collected.

  As can be seen from the examples and comparative examples described above, the constituent members of the simulated solar cell module could be easily separated and recovered by using an organic solvent having a specific chemical structure. Similarly, in the case of a solar cell module composed of a solar cell, a sealant, a back material, and glass, similarly, when an organic solvent having a specific chemical structure is used, the constituent members of the solar cell module are easily separated and recovered be able to.

Claims (5)

A solar cell module in which a solar cell module composed of a solar cell, a sealant, a back material, and glass is immersed in a solution containing at least one organic solvent selected from organic solvents represented by any of the following chemical structures Dismantling method.

(R _1, R _3, R _{4 and} R ₆ are hydrocarbon groups having 1 to 8 carbon atoms, and R ₂ , R ₅ and R ₇ are hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. .) The method for disassembling a solar cell module according to claim 1, wherein R ₂ , R ₅ and R ₇ are hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. The method for disassembling a solar cell module according to claim 1 or 2, wherein R ₁ , R ₃ , R ₄ , and R ₆ are hydrocarbon groups having 1 to 6 carbon atoms. The organic solvent is at least one organic solvent selected from propylbenzene, isopropylbenzene, pentylbenzene, methoxybenzene, ethoxybenzene, butylbenzene, and 1-isopropyl-4-methoxybenzene. The disassembly method of the solar cell module as described in 2. The method for disassembling a solar cell module according to any one of claims 1 to 4, wherein the sealant is an ethylene-vinyl acetate copolymer, polyvinyl butyral, or polyurethane.