Venice-based 9-tech has developed a thermomechanical process to recycle waste PV panels, with early results showing an 87% recovery efficiency from materials such as silicon, copper and silver.
The Italian startup 9-tech is developing a thermomechanical recycling process for discarded PV panels. Initial results show a recovery efficiency of 87% for materials such as silicon, copper and silver, at competitive energy consumption.
The recovered materials are said to have a purity level high enough for reuse in other applications. The process involves manual disassembly to remove the aluminum frame and junction box, followed by cutting the panels for removal of the encapsulant in a continuous oven designed to minimize energy loss, using a heat exchanger to provide the heat required before treatment.
“The process consists of an initial manual disassembly phase, during which the aluminum frame and junction box, mainly made of plastic and copper, are dismantled,” 9-tech CEO Pietrogiovanni Cerchier said. pv magazine. “The panels are then cut into 33cm strips to reduce their size and make them suitable for the next phase. The panel strips undergo heat treatment to obtain complete combustion of the EVA encapsulant.”
After this phase, copper strips, silicon cells and glass are mechanically separated. Rollers first remove the copper wires and the material is sieved to remove fine particles. A vibrating sieve then separates the PV cells from the glass.
The process also includes a smoke control system with a bag filter and activated carbon. Silicon is recovered as small pieces of foil of less than 20 cm² and a washing treatment has been tested to remove silver and aluminum.
The company optimizes processes for scale-up, completes life cycle assessments and explores ways to reuse recovered materials, especially silicon, across different value chains.
The pilot plant achieved a recovery efficiency of 87%. From 898 kg of PV panels, 581 kg of glass, 146 kg of aluminum, 14 kg of junction boxes, 26 kg of PV cells, 6 kg of copper tape, 0.45 kg of silver and 9 kg of dust were recovered.
“The analysis showed that the purity of the recovered materials was sufficiently high to be suitable for other applications,” Cerchier explains. “The recovered glass, aluminum and copper have demonstrated compliance with the specifications for end-of-waste status, in accordance with point 1.2 of Annex I to Council Regulation (EU) No 1179/2012 of 10 December 2012.”
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