Method for separating multilayer systems

Abstract

A separating fluid, method and use for separating multilayer systems, especially photovoltaic modules, for the purpose of recycling, which allow the separation of multilayer systems. Especially photovoltaic modules, in comparatively simple manner in terms of the processes used, in as environmentally friendly a manner as possible, at high recycling rates. For this purpose, the separating fluid is a nanoscale dispersion or a precursor thereof.

Claims

1. A method for separating multilayer systems comprising one or several layers comprising: washing the multilayer systems with a separating fluid comprising a nanoscale dispersion to form undissolved separated components, wherein the nanoscale dispersion comprises an organic component, an aqueous component and at least one surfactant; and collecting one or more of the undissolved separated components from the multilayer systems.

2. The method according to claim 1, further comprising: filling a container with the separating fluid; and generating a relative motion between the separating fluid and the container.

3. The method according to claim 2, wherein the relative motion is generated by at least one of rotation, stirring, vibrating or conveying of the separating fluid within the container.

4. The method according to claim 1, further comprising chopping the multilayer systems prior to the washing.

5. The method according to claim 1, further comprising generating defects penetrating the one or several layers of the multilayer system.

6. The method according to claim 1, further comprising sorting of the undissolved separated components by a swim-sink method.

7. The method according to claim 1, further comprising separation of the undissolved separated components by a filter method.

8. The method of claim 1, further comprising collecting the separating fluid after washing the multilayer system and recovering the separating fluid after the washing by separating the undissolved separated components of the separating fluid.

9. The method of claim 1, wherein the surfactant is selected from the group formed of anionic surfactants, non-ionic surfactants, amphoteric surfactants, or combinations thereof.

10. The method of claim 1, wherein the separation fluid contains at least one anionic surfactant and one or more surfactants selected from the group formed of non-ionic surfactants or amphoteric surfactants.

11. The method of claim 1, wherein the nano-scale dispersion further contains a hydrotrope for stabilization of the dispersion.

12. The method of claim 11, wherein the hydrotrope comprises a short-chain polar organic molecule, an organic acid, or a salt of an organic acid.

13. The method of claim 1, wherein the nanoscale dispersion contains a short-chain alcohol.

14. The method of claim 1 wherein the aqueous component has within the nanoscale dispersion a concentration of at least 60 wt. %.

15. The method of 1, wherein the multi-layer systems are mechanically shredded before the washing is performed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description and the accompanying drawings, in which

(2) FIG. 1 is a flow diagram of a method of using a separating fluid in accordance with an embodiment of the present invention.

(3) FIG. 2 is a diagram of another aspect of a method for separating multilayer systems in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) FIG. 1 shows a flow diagram for illustration of the method for separating multilayer systems, in particular photovoltaic modules, for the purpose of recycling.

(5) Modules with EVA bond in the glass-glass composite/glass plastic, possibly with frame, are suitable input material 1 for the method. In an upstream step of the method 2, any present electronic components, such as connection sockets, are disassembled from the input material 1. The upstream step of the method 2 can take place at a manual disassembly workplace. The input material 1 can also be waste materials or other composite materials, such as but not limited to, composite materials of polymers and paper.

(6) The next step 3 includes pre-chopping of the input material 1. The pre-chopping leads to an increased area of attack of the nanoscale dispersions. The increased area results in shortened process times. In step 4, the material acquired after chopping step 3 is subjected to size sorting by screening.

(7) Equally, the input material 5 may also be a quantity of composite materials without bonding, such as semi-finished goods. The input material 5 is supplied to a hammer mill 6 and chopped in the hammer mill 6. Dust produced in the chopping step 3 or the hammer mill 6 is separated into filtered air 8 and microparticles 9 according to the extraction step 7, preferably with a HEPA filter (HEPA: high efficiency particulate air filter).

(8) As a result of the screening, the input material 1 chopped in the chopping step 3 or the alternative input material 5 chopped in the hammer mill 6 is present in three different sizes according to the execution example described here. A screening step 4 separates coarse material and particles from each other that have different separating properties in the baths 10, 11, 12.

(9) The benefit of the screening step 4 is that large particles that are easier to filter can be washed off from large materials. On the other hand, small glass splinters with even smaller particles will results in a high filter/separation effort. The ratio of 95% of particles with sizes >5 mm to 5% of particles with sizes <1 mm can also be applied.

(10) The screening step 4 is performed with a simple tumbler. After the screening step 4, dosage containers (not illustrated in FIG. 1) can be used for interim buffering and will then serve to fill the baths 10, 11, 12 for performance of the actual separation method.

(11) The baths 10, 11, 12 are filled with shards of the input material 1 or the alternative input material 5 up to a volume of about 40%. The remaining roughly 60% of the volume of each of the baths 10, 11, 12 are topped up with nanoscale dispersions according to the invention. The nanoscale dispersion can be aligned in particular specifically with the input material 1 or the alternative input material 5 to achieve best process times at the lowest costs. It is also possible to use the nanoscale dispersions that can separate different photovoltaic modules of the above kind in the same way.

(12) The nanoscale dispersions according to the invention are made up as disclosed in the introduction of the description. In particular, they are made up according to one of the following compositions where the part missing to 100% is topped up with water:

Example 1

(13) TABLE-US-00001 Contribution to % by the aqueous Component weight Substance component Anionic 17.8 Leuna alkane sulfonate 30 11.8 surfactant (sodium alkane sulfonate mixture with an average chain length C15 (C12- C18) based on n-paraffin - 34% watery solution Non-ionic 5.9 Polyethylene glycol-mono- surfactant n- dodecyl/tridecyl/tetradecyl/- pentadecylether as substance mixture of compositions with 4 to 25 ethylenoxide units Hydrotrope 3.5 Cublen R 60 [N-(2- 1.4 hydroxyethyl)-N,N-bis- methylenephosphonic acid in the form of a 60% watery solution Co-surfactant 8.9 Butanol-2 Organ. Phase 7.0 Xylen (techn.) Addition 56.90 of water Watery 70.1 Total of addition of water component and contributions to the total watery component

Example 2

(14) TABLE-US-00002 Contribution to % by the aqueous Component weight Substance component Anionic 6.0 Leuna alkane sulfonate surfactant 95 (sodium alkane sulfonate mixture with an average chain length C15 (C12-C18) based on n-Paraffin) Non-ionic 6.0 Polyethylene glycol- surfactant mono-n-dodecyl/ tetradecylether as substance mixture with 9 ethylenoxide units Hydrotrope 2.0 Dimethylaminomethane- bis-phosphonic acid Co-Surfactant 9.0 Ethylhexanol Organic phase 8.0 Mesitylen Addition 69.0 of water Aqueous 69.0 Total of addition of component total water and contributions to the watery component

(15) In the nanoscale dispersions according to example 2, NaOH may be added to increase the pH value.

Example 3

(16) TABLE-US-00003 Contribution to % by the aqueous Component weight Substance component Amphoteric 5.0 N,N-dimethyl-N- surfactant tetradecyl- ammoniopropanesulfonate Non-ionic 6.0 Polyethylene glycol- surfactant mono-n-dodecyl/ tetradecylether as substance mixture with 9 ethylenoxide units Hydrotrope 2.0 Dimethylaminomethane- bis-phosphonic acid Co-Surfactant 9.0 Ethylhexanol Organic phase 7.0 Hydrosol P 180 EA Addition 71.0 of water Watery 71.0 Total of addition of water component and contributions to the total watery component

(17) In example 3, the anionic surfactant is replaced by an amphoteric surfactant in contrast to examples 1 and 2.

Example 4

(18) TABLE-US-00004 Contribution to % by the watery Component weight Substance component Amphoteric 3.0 N,N-dimethyl-N- surfactant tetradecyl- ammoniopropanesulfonate Anionic 4.0 Leuna alkane sulfonate 95 surfactant (sodium alkane sulfonate mixture with an average chain length C15 (C12- C18), based on n-paraffin Non-ionic 6.0 Polyethylene glycol- surfactant mono-n-dodecyl/ tetradecylether as substance mixture with 9 ethylenoxide units Hydrotrope 2.0 Dimethylaminomethane- bis-phosphonic acid Co-surfactant 9.0 Butyl glycol ether Organic phase 5.0 Diesel fuel Addition 71 of water Watery 71.0 Total of addition of water component and contributions to the total watery component

(19) In example 4, an anionic surfactant as well as an amphoteric surfactant is used in addition to the non-ionic surfactant.

(20) One or several of the nanoscale dispersions listed act for a certain exposure time that depends on the properties of the input material 1 or the alternative input material 5 in the baths 10, 11, 12. The effect occurs due to comprehensive wetting in several application points where the separating fluid can enter between the composite layers to be separated, move along the interface and dissolve the bond there, for a certain time. This does not have to take place in submersion containers 11, 12, 13.

(21) After the separating process in the submersion containers 10, 11, 12, a loaded separating fluid 13 is treated in a separation step 14. The separation step 14 serves to separate the components of the input material 1 or the alternative input material 5 that are present after washing in the submersion containers 10, 11, 12, as well as the separating fluid in the form of nanoscale dispersion. This step is only illustrated as a schematic in FIG. 1.

(22) In the simplest case, a swim-sink separation in connection with suitable filtering is sufficient. The light weight particles in the loaded separating fluid with large surface-volume ratios of the removed layers may be separated from larger, heavier particles such as glass fragments with small surface-volume ratios. The separation takes place using gravity, the flow conduct and/or the surface tension. Simple filtering can also be used for the purpose of the separation. The remaining parts, i.e. mainly glass, EVA and aluminum, are separated in subsequent process steps that can also be performed in subsequent areas of the facility.

(23) For example, EVA can be separated by the swim-sink separation, glass by depositing in the same container, aluminum by the separation of the non-ferrous components. These steps can each be performed in separate areas of the facility or in the same area of the facility.

(24) As shown in FIG. 1, precious metals 15, EVA film 16 and non-ferrous separations 17 are separated from the loaded separating fluid 13. The term non-ferrous separation 17 means separations of non-ferrous components, such as glass or aluminum. In a separate separation process that is not detailed further in FIG. 1, the non-ferrous separations 17 in turn are once again separated into the recyclable materials glass 18 and the aluminum frame 19. The recyclable materials, i.e. precious metals 15, EVA film 16, non-ferrous separations 17, comprising glass 18 and aluminum frame 19, are not dissolved. Therefore, the separation in step 14 is technically simpler compared with the art. The quality of the resulting recycling materials 15, 16, 17, 18, 19 regarding reusability is not limited by the recycling processes as such.

(25) The electronic components 20 resulting from the upstream step of the method 2 during disassembly of electronic components can also be delivered for recycling.

(26) After the upstream step of the method 2, the method can thus be structured in the following three procedural groups:

(27) Phase I: Pre-chopping and sorting by size

(28) Phase II: Wash with nanoscale dispersion

(29) Phase III: Production of suitable fractions for utilization

(30) FIG. 2 schematically shows another aspect of the method for separating the multilayer systems. As shown in the schematic flow chart according to FIG. 2, multilayer material 21 to be separated is supplied to a facility 22 for separating the multilayer material. The multilayer material 21 can optionally be supplied to a preliminary stage 100 for disassembly first. In the preliminary stage 100, pieces to be treated separately, e.g. pieces not made of the multilayer material to be separated, are removed. In the preliminary stage 100, pieces of the multilayer materials 21 to be separated that must be subjected to a different treatment, e.g. than a main component of the multilayer material, due to the type of the multilayer materials, can also be separated.

(31) After passing the preliminary stage 100, the part of the multilayer material 21 that remains after disassembly is supplied to another preliminary stage 200 for production of attack points. Alternatively, the multilayer material 21 can also be directly supplied to the preliminary stage 200 for production of attack points within the facility 1000 for separating the multilayer materials.

(32) This will be suitable if disassembly of the multilayer material 21 is not required or desired. Within the preliminary stage 200 for production of attack points, defects penetrating one or several layers of the multilayer system are produced to increase the area of the attack points of the separating fluid. This can be done by scratching of the multilayer system with mechanical cutting agents, by treatment with laser jets, by blasting with sharp-edged particles, e.g., sand blasting, by bending, crushing, shredding, grinding or other common procedures known to the specialist as such.

(33) After the preliminary stage 200 for production of the attack points, the multilayer material 21 is supplied to the interim storage stage 250. In the interim storage stage 250, it is also possible to ensure supply suitable for the subsequent processing stage. In the interim storage stage 250, different supply goods can be mixed as well.

(34) From the interim storage stage 250, which contains the interim storage in suitable containers, the multilayer material 21 to be processed is supplied to a wetting stage 300. Within the wetting stage 300, the multilayer material 21 to be separated is wetted with the separating fluid. This is done in a submersion bath containing the separating fluid or in the form of a sprinkler lane.

(35) After the wetting stage 300, the multilayer material 21 to be separated goes through a separating stage 400. Within the separating stage 400, the layer material delaminated during the wetting stage 300 is separated from a substrate material as part of the multilayer material 21 and taken up by the separating fluid without being dissolved in the separating fluid.

(36) The process may be facilitated by circulation of the separating fluid according to the invention. This is indicated by the arrows between the stages 300 and 400 in FIG. 2.

(37) A separation stage 500 follows the separating stage 400. During the separation stage 500, layer fragments taken up by the separating fluid in the separating stage 400 are separated by a suitable method. This may be done by suspension in the air bubble flow according to a floating method, swim-sink separation or filtration.

(38) The Separation stage 500 is followed by a fragmenting stage 600 in which the layer fragments separated during separating stage 400 and separated from the liquid separating fluid according to the invention in the separation stage 500 are fragmented into different material fractions.

(39) After the fragmenting stage 600, the individual material fractions a, b, c are further refined in an after-treatment stage 700. Refining of the individual material fractions a, b, c may, e.g., comprise of breaking up, cleaning or physical or chemical processing.

(40) Finally, the material fractions a, b, c refined in the scope of the after-treatment stage 700 are supplied to a packaging stage 800 and packed for use separately.

LIST OF REFERENCE NUMERALS

(41) 1 Input material 2 Upstream step of the method 3 Chopping step 4 Screening 5 Alternative input material 6 Hammer mill 7 Extraction step 8 Filtered air 9 Microparticles 10 Bath 11 Bath 12 Bath 13 Loaded separating fluid 14 Separation step 15 Precious metals 16 EVA film 17 Non-ferrous separations 18 Glass 19 Aluminum frame 20 Electronic components I Phase of the method II Phase of the method III Phase of the method 21 Multilayer material 22 Facility for separating multilayer material 100 Preliminary stage for disassembly 200 Preliminary stage for production of attack edges 250 Interim storage stage 300 Wetting stage 400 Separating stage 500 Separation stage 600 Fragmenting stage 700 After-treatment stage 800 Packaging stage