Environmentally sustainable methodology for the extraction of ethyene vinyl acetate (EVA) residue from EoL PV panel dismantled by hot knife

EVA is the encapsulation material holding the c-Si PV module components together. In order to upscale the cover glass, it is necessary to remove the EVA film effectively. With hot knife technique, glass is separated without breaking, but a layer of EVA remains on the surface. Chemical extraction techniques to separate EVA use common toxic organic chemicals such as Toluene, with long separation process time. Thus, inefficient separation of EVA from the panel with residues remaining on the surface, which will oxidize and change the glass furnace atmosphere, have highlighted the need to develop new methods. We demonstrated an efficient and environmentally friendly extraction method for the extraction of the thick layer of EVA-adhered intact glass after dismantled from module by the hot knife applied manually. The effectiveness of this method was investigated by comparing it with a common solvent Toluene extraction through advanced characterizing techniques. Also, the results showed that the EVA extraction time has reached extremely short time of 4 h without using any thermal process that would emit toxic vapors. We can conclude that with the developed method, cleaned glass can be safely re-used as feedstock for solar glass production, which requires strict chemical specifications.