Resource recovery from spent crystalline-silicon solar modules by using microwave pyrolysis, acid leaching and chemical etching
Journal
Process Safety and Environmental Protection
Journal Volume
194
Start Page
47
End Page
57
ISSN
0957-5820
Date Issued
2025-02
Author(s)
DOI
10.1016/j.psep.2024.12.017
Abstract
In this study, microwave pyrolysis, two-stage acid leaching, precipitation and chemical etching methods were carried out for resource recovery from spent c-Si solar modules. Compared with conventional pyrolysis, microwave pyrolysis should be a better pretreatment process, because it can provide higher aluminum recovery rate and would not alter the surface structure and composition of c-Si solar modules as conventional pyrolysis did. The recovery products, including aluminum, silver and silicon crystal, were obtained with the recovery rates of 94.90 %, 95.74 % and 83 %, and the purities of 99.63 %, 100 % and 99.98 %, respectively. Cylindrical diffusion and pseudo-second-order models best fit the experimental data of sulfuric acid and nitric acid leaching, respectively, implying that the mechanisms of aluminum and silver dissolution would be different. The return on investment of spent c-Si solar modules recycling by using the methods involved in this study would be approximately 113 %. Therefore, total resource recovery from spent c-Si solar modules can be nearly achieved by using these methods, showing great potential for commercial applications and high possibility of establishing circular economy. The operational parameters and reaction kinetics found in this study can be applied to other kinds of solar modules or electronic waste for resource recovery and environmental protection.
Subjects
Acid leaching
Chemical etching
Crystalline-silicon solar modules
Microwave pyrolysis
Reaction kinetics
Resource recovery
Publisher
Elsevier BV
Type
journal article