PV back sheet recovery from c-Si modules using hot knife technique

Journal article, 2024

The primary challenge in recycling crystalline silicon (c-Si) photovoltaic (PV) modules is separating the polymeric fractions, including back sheets, from the module structure. Thermal treatment, commonly used for this purpose, adversely affects the environment by releasing harmful gases and degrading polymers. With this in mind, this study introduces a novel hot knife method to efficiently separate and recover the back sheet layer from c-Si PV modules, a primary source of toxic gases during thermal treatment. A thin and highly conductive knife was selected for the hot knife-cutting process. The heating of the knife was accomplished by connecting it to a hot air gun, which offers complete parameter control, enabling precise adjustments to maintain the knife at the required temperature. Experimental tests were conducted to determine the best conditions for separating the back sheet from solar cells. The effectiveness of this method was evaluated using FTIR, TGA, and SEM-EDS. The findings reveal that the proposed hot knife technique effectively separate the back sheet layers from c-Si PV panels without breaking their integrity. The recovered back sheet can significantly reduce environmental pollution risks by preventing polymer material depletion. As a result, the production gases that arise from the degradation of back polymers can be eliminated.