Green Chemistry Leaching and Electrowinning for Lead Recovery from Silicon Solar Panels

With solar module installations increasing exponentially over the past few decades, end-of-life technology is imperative for handling the predicted mass amount of solar panel waste. Of all the elements found in solar panels, lead (Pb) recovery is of upmost importance because it is a known teratogen and organ toxin. Despite this, there is very little literature discussing Pb recovery from end-of-life solar modules. The research performed in this dissertation advances Pb recovery from solar panels using the principles of green chemistry. A two-step leaching and electrowinning approach is explored. Two green acids (acetic acid (AcOH) and methanesulfonic acid (MSA)) are investigated for leaching and electrowinning. The conditions necessary for fast Pb leaching in each of these acids are determined. Once the Pb has leached into solution as Pb2+, electrowinning is used to recover metallic Pb from the system. Metallic Pb can be directly fed back into the solar economy for manufacturing of new solar panels, making the industry circular. The electrowinning process is optimized for three different arrangements. 99 % recovery from synthetic solutions is achieved for all three configurations explored. A proof-of-concept is demonstrated on real solar panel waste using each of the two acids.