Recycling of Discarded Photovoltaic Modules Using Mechanical and Thermal Methods

Abstract

Photovoltaic installations have experienced very significant growth worldwide since the early 2000s, driven by growing industry
and government interest in mitigating climate change, decarbonization, and increasing energy demand. The most prevalent worry
with photovoltaic (PV) panels is that their age is limited and they will eventually need to be decommissioned. With the expansion
of PV production capacity worldwide, a large amount of PV panel waste will be generated in the future. Since PV panels contain
heavy metals such as lead, cadmium and tin, this can have a significant impact on the environment. In addition, they also contain
valuable metals (e.g. silver, gallium, indium and germanium) and standard materials (e.g. aluminum, glass) that represent a valuable
opportunity when recovered. Developing a sustainable, environmentally friendly recycling process and maximizing the recovery of
components from PV panels at the end of their life is expected to solve the PV waste problem. In this work, three alternative methods
for recycling silicon-based (mono/polycrystalline) PV panels were investigated based on a combination of mechanical and thermal
processes. The three alternative methods are a hammer crusher followed by thermal treatment and square sieve, a shredder crusher
followed by thermal treatment and square sieve, and thermal treatment followed by a slotted sieve. X-ray diffraction (XRD) and X-ray
fluorescence (XRF) were performed to evaluate the properties of the obtained products. The results showed that thermal treatment
followed by slotted sieve is the most effective method for direct glass recovery for all types of photovoltaic modules studied.