Awards 2022

A second life for wind turbine blades: recycling the cores

UNIFEWith wind power expanding by leaps and bounds, all those turbine blades eventually need to be recycled, including the rigid PVC foam inside. The University of Ferrara, working with Swedish-based foam core manufacturer Diab, developed a way to re-use them.

That kind of foam is difficult to recycle “because the PVC is in a polyurea/isocyanurate network,” says Monica Bertoldo, Associate Professor at the university’s Department of Chemical, Pharmaceutical and Agricultural Sciences.

Working with Diab, we developed a new process based on depolymerisation by glycolysis of the cross-linked portion of the foam, enabling the recovery by filtration of 90% pure PVC,” Monica says. “It has thermal properties comparable to virgin PVC.”

What about the non-PVC part of the foam after glycolysis? “It was successfully used as a chain extender to produce thermoplastic polyurethane (TPU) with full reuse of all the original foam components,” Monica says. “This allows savings of 10 % of the isocyanate needed for TPU synthesis.”

There’s more work ahead, since the depolymerisation process was developed at laboratory scale. “With additional funding, further research is needed to scale it up,” says Monica. “We need to formulate the recovered PVC to use as a second material and to use the depolymerized fraction for TPU production on an industrial scale.