Dissolution of ethylene vinyl acetate in crystalline silicon PV modules using ultrasonic irradiation and organic solvent

Using probe-type ultrasonic irradiation, the dissolution of ethylene vinyl acetate (EVA) in photovoltaic (PV) modules was investigated in various organic solvents, including O-dichlorobenzene (O-DCB), trichloroethylene (TCE), benzene, and toluene. The experiments were carried out at different solvent concentrations, temperatures, ultrasonic powers, and irradiation times. In the presence of 450 W of ultrasonic radiation, EVA in PV modules was completely dissolved in 3 M toluene at 70 °C; however, the PV cell was damaged due to the swelling of EVA. At an irradiation power of 900 W, the dissolution ratio was greater than that obtained at a power of 450 W, and the effects of ultrasonic power were confirmed at 70 °C. In TCE and benzene, a decrease in the dissolution of EVA was observed as the temperature increased from 55 to 70 °C due to the occurrence of pyrolysis and pyrolytic reactions, which were attributed to the low boiling point and ultrasonic degradation of the solvent, respectively. Except when O-DCB was used, cracks were observed in the PV cell, and the complete dissolution of EVA was attained. Thus, O-DCB is the most effective solvent for recovering PV cells via ultrasonic irradiation.