painel fotovoltaico, célula fotovoltaica, prata, lixiviação, tioureia
Name: LUANA SEIDEL ALBUQUERQUE
Publication date: 27/02/2024
Examining board:
Name |
Role |
|---|---|
| HUGO MARCELO VEIT | Examinador Externo |
| LUCIANA HARUE YAMANE | Presidente |
| RENATO RIBEIRO SIMAN | Examinador Interno |
Summary: Among renewable energies, solar energy is the second most used in Brazil, and the durability of a photovoltaic panel is approximately 25 years. However, it is possible for the panel to become unusable before this time due to damages. As the market expands, an increase in the production of this waste is predicted, and it is crucial to recycle photovoltaic panels. Among the panels produced so far, the crystalline silicon panel is the most used in the world and it contains glass, aluminum, metallic filaments, EVA, as well as silicon, copper, lead, silver, among other metals. The metal that stands out in the photovoltaic panel due to its added value and criticality on the Earth is silver. With the aim of reusing the silver contained in photovoltaic panels, this study aims to determine the optimal conditions and potential for its extraction from unusable cells through leaching with thiourea. For this purpose, the gravimetric composition of the crystalline silicon photovoltaic panel and the initial concentration of metals (Ag, Cu, and Pb) were determined. The Box-Behnken experimental design was used at three equidistant levels to identify the best configuration of control variables for extraction: thiourea concentrations, sulfuric acid, ferric ion, and solid-liquid ratio. The results obtained under optimal extraction conditions were 82%, with sulfuric acid at 0.1 mol/L, thiourea at 20 g/L, ferric ion at 5 g/L, and solid-liquid ratio of 125 g/L at a constant temperature of 25°C and rotation of 200 rpm. Furthermore, statistical modeling identified that the significant variables were sulfuric acid, solid-liquid ratio, ferric ion, and the interactions sulfuric acid-ferric ion and sulfuric acid-solid-liquid ratio.
