Comparative assessment of mechanical–thermal recycling processes for crystalline silicon photovoltaic modules

Salazar R.B.J.; Condori Canaza I.Y.; Anconeyra Maque G.V.; Delgado Sarmiento P.K.; Flores Calla S.S.; Cheje Machaca D.M.; Espinosa D.C.R.; Tenório J.A.S. · Solar Energy Materials and Solar Cells (2026) · DOI: 10.1016/j.solmat.2026.114607

Resumen

The increasing deployment of crystalline silicon (c-Si) photovoltaic modules highlights the need for recycling strategies capable of recovering valuable materials while improving process selectivity. This study compares two mechanical–thermal recycling routes: (i) conventional full thermal delamination and (ii) selective thermal treatment following particle-size classification. The performance of both routes was evaluated in terms of polymer removal, glass recovery, material liberation, and metal distribution. Thermal treatment under an oxidizing atmosphere (500 °C, 1 h) achieved polymer degradation efficiencies above 95%. However, the selective route reduced the polymer fraction fed to thermal treatment from 11.2 wt% to 7.3 wt% through preliminary sieving, removing approximately 35% of the polymeric material before thermal processing. Particle-size classification revealed that more than 90% of the metallic components were concentrated in fractions smaller than 2 mm, while silver was preferentially enriched in the finest fraction (<0.08 mm), reaching concentrations of up to 0.24 wt%. The selective route achieved a glass recovery of 98.6%, compared with approximately 90% in the conventional process, while maintaining SiO2 purities above 95%. In addition, selective thermal treatment improved phase liberation while reducing contamination by carbonaceous residues generated during polymer degradation. These results demonstrate that early particle-size classification enhances process selectivity and material recovery by reducing the amount of material requiring thermal treatment. This approach provides a scalable mechanical–thermal recycling strategy for end-of-life crystalline silicon photovoltaic modules.

Instituciones: Universidad Nacional de San Agustín de Arequipa; Universidad Católica de Santa María