Life cycle assessment of decommissioned silicon photovoltaic module recycling using different technological configurations in China.

ABSTRACT

The intricate encapsulation structure and material composition of photovoltaic modules necessitate full materials recycling involving multiple stages and different technological configurations, thereby increasing environmental burden of recycling process. Consequently, environmental impact assessments are imperative. However, previous studies primarily focused on a single technology or compared different technologies within a specific recycling stage, overlooking various technological configurations and thus engendering incomprehensive assessment. Hence, we employ a comparative life-cycle assessment to evaluate the environmental performance of six recycling alternatives with different technological configurations for silicon photovoltaic waste in China, which encompasses five recycling stages and glass/silicon remanufacturing processes. Results shows thermal delamination reduces the normalized environmental impact by 8.73% and 4.62% compared with mechanical and chemical delamination, respectively; electrolysis for metals extraction carries 35.72%-36.35% higher environmental benefits than precipitation. Additionally, introducing silicon/glass remanufacturing provides an additional 6.27%-11.55% environmental benefits. Therefore, integrating disassembly, thermal delamination, leaching & etching, electrolysis, and remanufacturing exhibits the best environmental performance, with -4796 kg CO2-eq/tonne carbon emission and -46400 MJ/tonne energy demand. Environmental hotspots analysis identifies key contributors to environmental impact and benefits. Further sensitivity analysis highlights the importance of enhancing silver and copper recovery efficiency. Finally, targeted strategies are proposed for green recycling routes of photovoltaic waste.