Recovery and analysis of polymeric layers from waste solar modules by chemical route

Abstract

Economical process for recovery/recycling of materials from waste modules is important for the overall sustainable development of PV sector. In the present investigation, the polymeric layers, Ethylene Vinyl Acetate (EVA), back-sheet, and other materials were recovered using single organic solvent toluene. The recovered EVA and back-sheet were characterized by various techniques such as Raman spectroscopy, Fourier transform spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), Thermogravimetric analysis (TGA), and Differential scanning calorimetry (DSC) to check their properties. The Raman and FTIR spectroscopy revealed that the recovered EVA and back-sheet have similar peaks as that of reference materials, implying no significant changes in composition occurred during the recovery process. The recovered EVA and back-sheet have a semi-crystalline structure similar to their respective reference materials as confirmed by XRD spectra. The TGA measurements confirm that the thermal stability temperature of recovered EVA (285 °C) and back-sheet (380 °C) are comparable to their respective reference materials. The recovered polymeric layers may be reused in solar panels or in the polymer industry. Also, ∼ 97 % of toluene was recovered and the same was purified by distillation process and observed that distilled toluene has equivalent UV–visible absorption bands to fresh toluene. With the recovery of solvent, polymeric layers, and other materials, the proposed method will be economically viable for the sustainable management of waste solar modules.