Innovative hydrothermal technique in efficient disengagement of waste solar panels

Abstract

The delamination of layers of waste solar panels remains a major challenge due to the lack of effective solutions for removing the adhesive between layers. In this study, a novel efficient method for disengagement of glass from the rest of the module is introduced, in which only water is used under high pressure (<3 MPa) and relatively low temperatures (230-250 °C) in a hydrothermal reactor, allowing for facile separation of the glass from the interlayer. The other layers of the module can also easily be peeled apart in subsequent processes. The separated glass is free of metals and polymers that can be utilized directly for further applications. The benefits of this method include no use of chemicals, preservation of the recovered materials' quality (i.e., interlayers, Si sheet, and glass), relatively low-temperature operation, no hazardous gas generation, and reduced energy consumption. A pilot scale design of the method has been proposed for processing a full panel, demonstrating its industrial viability.

Keywords: Delamination; Disengagement; End-of-life solar panels; Hydrothermal; PV waste upcycling.