Development of eco-friendly pretreatment processes for high-purity silicon recovery from end-of-life photovoltaic modules

Abstract

This study examines the efficacy of photovoltaic (PV) recycling processes and technologies for the recovery of high-purity silicon powder from waste solar modules. In order to facilitate the simplification of complex processes, such as the conventional nitric acid dissolution, solvent and ultrasonic irradiation, and solvent dissolution, a variety of mechanical separation processes have been established. These processes are designed to enhance the efficiency and effectiveness of the aforementioned processes. And a novel method for separating EVA from recycled Si powder was devised, which studied the WGS process using aqueous solutions of H₂O, HNO₃, and NaCl with different specific gravities. The WGS process using NaCl solution demonstrated superior performance, removing over 94% of the EVA, requiring less energy input and producing 73% less CO₂ emissions compared to the thermal process. These technologies facilitate the transition towards a circular economy and bolster the implementation of carbon-neutral initiatives.