DE102013112004A1 - Recycling of photovoltaic modules and / or solar modules - Google Patents

Abstract

The description includes a method for recycling a photovoltaic module and / or solar module, wherein the photovoltaic module and / or solar module comprises silicon, comprising the steps of: dissolving the silicon in a solution having a pH above 7.5, 2 and depositing the silicon in an electrolytic bath or in a solution with a pH above 7.5, 3.

Description

FIELD OF THE INVENTION

The present invention relates to a method for recycling photovoltaic modules and / or solar modules.

BACKGROUND OF THE INVENTION

In the prior art photovoltaic modules and / or solar modules are known which can generate electrical energy from solar energy.

SUMMARY OF THE INVENTION

Photovoltaic modules and / or solar modules have a limited life. The efficiency of photovoltaic modules and / or solar modules may decrease over time. In addition, they can be damaged or it may be useful to replace them with more efficient photovoltaic modules and / or solar modules. At the end of the life of the photovoltaic modules and / or solar panels, they can be recycled to reuse their components. There are also legal requirements that require recycling and / or take back. The photovoltaic modules and / or solar modules include, for example, glass, plastics, silicone, different metals, for example aluminum, copper, tin, silver and / or gold, and silicon.

It is therefore an object to provide a method which enables a recycling of photovoltaic modules and / or solar modules.

As a first embodiment of the invention, a method for recycling a photovoltaic module and / or solar module is provided, wherein the photovoltaic module and / or solar module comprises silicon, comprising the steps of: dissolving the silicon in a solution having a pH above 7.5 and Depositing the silicon in an electrolytic bath or in a solution with a pH above 7.5.

According to the invention, the silicon of the photovoltaic modules to be recycled and / or solar modules is dissolved by a solution having a pH of more than 7.5. This removes the silicon, thus allowing the remaining components (e.g., recyclables) of the photovoltaic modules and / or solar modules to be easily mechanically separated.

Exemplary embodiments are described in the dependent claims.

According to an exemplary embodiment of the invention, a method is provided, wherein the dissolution of the silicon by heating the bath, in particular to a temperature between + 45 ° Celsius to + 90 ° Celsius, and / or by an ultrasonic source and / or by a Circulation of the solution / the bath, in particular by a circulation pump with filter unit, is supported.

If supporting measures are taken, such as heating the solution with a pH above 7.5 and / or ultrasonication of the solution, the dissolution process can be accelerated.

In a further embodiment of the invention, a method is provided, wherein the deposition by a heating of the bath and / or by a circulation of the solution / the bath, in particular by a circulation pump with filter unit, is supported.

Heating the electrolytic bath accelerates the deposition process. According to a further exemplary embodiment of the present invention, a method is provided, wherein the deposition of electrically conductive carrier materials as anode or cathode, in particular on stainless steel plates, is effected by a direct current flow through the electrolytic bath.

According to an exemplary embodiment of the invention, there is provided a method further comprising the steps of prior to dissolving the silicon: removing a comprehensive frame from the photovoltaic module and / or solar module and / or peeling off a carrier layer, the carrier layer carrying the glass, silicon and / or metal conductor of the photovoltaic module and / or solar module is provided and / or wherein the carrier layer consists of plastic or silicone.

Advantageously, framing elements of the photovoltaic modules and / or solar modules and / or plastic carriers for carrying the glass of the photovoltaic modules and / or solar modules are removed prior to immersion of the photovoltaic modules and / or solar modules in the solution. In addition, the photovoltaic modules and / or solar modules can be cut / sawn into smaller units in order to be able to obtain a better packing density within the baskets / collecting containers.

In a further embodiment of the invention, a method is provided, wherein the detachment of the carrier layer by cold, in particular by cooling to -15 ° Celsius or to a temperature between -40 ° to -50 ° Celsius and -100 ° Celsius or below.

As an idea of the invention can be considered to enable a recycling of a photovoltaic module and / or solar module in that one of the connecting substances of the photovoltaic module and / or solar module, the silicon, is dissolved. For example, by a solution with a pH above 7.5, the silicon of the photovoltaic module and / or solar module can be resolved. After the silicon has been dissolved, the parts of the photovoltaic modules and / or solar modules can be easily disassembled. After the silicon has been dissolved in a solution having a pH above 7.5, it can be recovered by an electrolytic process by deposition on an electroconductive support, preferably stainless steel sheets used as the anode and cathode. Plastics and / or silicone as a carrier material for the glass of the photovoltaic modules and / or solar modules can be removed beforehand, for example by exposure to cold.

Of course, the individual features can also be combined with each other, which can also be partially beneficial effects that go beyond the sum of the individual effects.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details and advantages of the invention will become apparent from the embodiments illustrated in the drawings. Show it

1 a flow diagram of a method according to the invention,

2 the arrangement of collecting containers in a solution with a pH above 7.5 for the dissolution of the silicon of the solar cells,

3 an electrolytic bath with a pH greater than 7.5 solution for the recovery of silicon,

4 the method according to the invention in various stages.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows a flowchart of the method according to the invention, in which as a first step 1 dismantling of the photovoltaic modules to be recycled and / or solar modules takes place. In this case, a comprehensive aluminum frame is first removed from the photovoltaic modules and / or solar modules. In addition, plastic layers, which are used as a carrier material, replaced by cold. For this purpose, the solar cell is at a temperature of -15 ° Celsius or between -40 ° to. -50 ° Celsius or cooled to -100 ° Celsius or below. In a next step 2 For example, the solar cells are immersed in a solution having a pH above 7.5, preferably a caustic soda solution containing 5% to 30% caustic. As a result, according to the invention, the silicon can be dissolved. The solution can be kept in motion by a circulation pump with filter unit (circulating) and / or filtered. For example, the solar cells can remain in the liquor for 4 to 8 hours, whereby the silicon can be dissolved almost completely (about 98-99%). For this purpose, the photovoltaic modules and / or solar modules are immersed in a bath / collecting container in the bath. After the silicon has been dissolved, the basket can be removed from the solution, wherein in the basket, the other components of the photovoltaic modules and / or solar modules are contained, namely glass, substrates and metallic interconnects. These remaining ingredients can, as the silicon has been removed, in a further step 4 be separated mechanically in a simple manner.

2 shows a bath / basin 5 in which a solution having a pH above 7.5, in particular a 5% to 30% caustic soda, is filled. In the basin 5 become containers / baskets / collection containers 10 introduced, in which the photovoltaic modules to be recycled and / or solar modules are arranged. Previously, the plastic carriers can be replaced as a carrier material of the photovoltaic modules and / or solar modules of the photovoltaic modules and / or solar modules. In addition, advantageously, extensive frames, such as aluminum, have been removed. In the solution with a pH above 7.5, the silicon is dissolved out of the photovoltaic modules and / or solar modules. To assist the dissolution process, preferably the caustic soda solution with a heat source, preferably hot plates 7 , heated. In addition, the dissolution process can be performed by an ultrasonic source 9 additionally supported. As soon as the silicon has been removed from the photovoltaic modules and / or solar modules, the collecting containers become 10 from the bathroom 5 taken. The photovoltaic modules and / or solar modules can, as the silicon has been removed, mechanically broken down into their individual parts, in particular glass and metallic interconnects. The collection containers / baskets 10 may be made of metal and / or plastic, preferably of titanium, to be chemically resistant to the solution having a pH above 7.5.

3 shows the bath 5 after the baskets 10 taken with the photovoltaic modules and / or solar modules. It may be in a further step, the electrically conductive carrier, preferably stainless steel sheets 11 as anodes or cathodes in the solution 5 be dipped and these are connected to a DC power source. This results in an electrolytic bath 5 to remove the silicon from the solution with a pH above 7.5. The silicon is in amorphous form on the electrically conductive supports, preferably the stainless steel sheets 11 , deposited and can be scraped / removed from these.

4 shows the process according to the invention with a pool / bath 5 into which a solution having a pH above 7.5 is introduced, for example a 5% to 30% sodium hydroxide solution. First of all, the silicon from the photovoltaic modules and / or solar modules in the baskets can thereby be produced 10 be solved. In a further step, electrically conductive supports, preferably stainless steel sheets 11 , as anode and cathode in the bath 5 dipped, resulting in the application of a DC voltage to the stainless steel sheets 11 a galvanic process results. After connection to the power supply, the silicon separates from the stainless steel sheets 11 from. From time to time, additional caustic soda and / or water should be added to the bath for regeneration 5 be filled to compensate for evaporation losses, in this case, the pH should be monitored, for example, with a stationary measuring station. In detail, the method according to the invention comprises the steps of: separating frames comprising the solar modules, dissolving plastic layers with cold action, dissolving the silicon by means of ultrasound, heat and a solution with a pH above 7.5, recovering the silicon with direct current, heat and a solution with a pH above 7.5 and mechanical separation of the residual recyclables such as glass, metal strips, silicone and plastics. The dissolution and / or deposition process may be through a circulation pump 8th by circulating the solution within the bath 5 be supported / accelerated. At the circulation pump 8th may be arranged a filter unit, which is provided for filtering / cleaning the solution.

It should be noted that the term "comprising" does not exclude other elements or method steps, just as the term "a" and "an" does not exclude multiple elements and steps.

The reference numerals used are for convenience of reference only and are not to be considered as limiting, the scope of the invention being indicated by the claims.

LIST OF REFERENCE NUMBERS

1

 dismantling

2

 Dissolution of silicon

3

 Depositing silicon

4

 Obtain valuable materials

5

 Bath / pool

6

 hood

7

 heating plate

8th

 Circulation pump with filter unit

9

 ultrasound source

10

 Baskets for receiving solar cells

11

 Stainless steel sheets as anode or cathode

Claims (6)

Method for recycling a photovoltaic module and / or solar module, wherein the photovoltaic module and / or solar module comprises silicon, comprising the steps of: dissolving the silicon in a solution having a pH above 7.5 ( 2 ) and depositing the silicon in an electrolytic bath ( 5 ) or in a solution with a pH above 7.5 ( 3 ). The method of claim 1, wherein the dissolution of the silicon ( 2 ) by heating the bath ( 5 ), in particular to a temperature between + 45 ° Celsius to + 90 ° Celsius, and / or by an ultrasound source ( 9 ) and / or by circulating the solution / bath ( 5 ), in particular by a circulation pump ( 8th ) with filter unit. Method according to one of claims 1 or 2, characterized in that the deposition ( 3 ) by heating the bath ( 5 ) and / or by circulating the solution / bath ( 5 ), in particular by a circulation pump ( 8th ) with filter unit. Method according to one of the preceding claims, characterized in that the deposition ( 3 ) on electrically conductive carrier materials as the anode or cathode, in particular on stainless steel sheets ( 11 ) by a DC flow through the electrolytic bath ( 5 ) he follows. Method according to one of the preceding claims, further comprising the steps before the dissolution of the silicon ( 2 ): Removing a comprehensive framework ( 1 ) of the photovoltaic module and / or solar module and / or detachment of a carrier layer ( 1 ), wherein the carrier layer for supporting the glass, silicon and / or metal conductors of the photovoltaic module and / or solar module is provided and / or wherein the carrier layer consists of plastic or silicone. A method according to claim 5, characterized in that the detachment of the carrier layer ( 1 ) by cold, in particular by cooling to -15 ° Celsius or to a temperature between -40 ° to -50 ° Celsius or to -100 ° Celsius or below.

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