REFRESH Work Package 2 – Development and customisation of recycling processes is designing several processes for treating end-of-use wind turbine blades. CIRCE is responsible for developing two alternative energy-efficient thermochemical routes for the valorisation of wind blade waste based on microwave-assisted pyrolysis (MW-PYR) and microwave-assisted solvolysis (MW-SOL).

The aim is to recover glass and carbon fibre from fibre-reinforced composite parts, preserving most of their initial mechanical properties, as well as valorise the resins (epoxy- or polyester-based) into valuable molecules either to be used as fuels or as building blocks for the production of recycled resins or second generation chemicals.

Microwave-assisted heating mechanism.

The innovation behind this development consists in taking advantage of the different physico-chemical and dielectric properties of the composite materials to provide a selective microwave-assisted heating of the target materials. This leads to faster, volumetric and more energy-efficient degradation of resins under milder operating conditions with respect to conventionally heated composites valorisation processes. The main advantages are a better control of the heating pattern and, thus, on the pyrolysis/solvolysis oil product distribution.

CIRCE is using its technology to valorise shredded, sorted and dried blade parts supplied by MTB Manufacturing, and is assessing MW-PYR and MW-SOL performance and product characteristics. CIRCE is suppling glass and carbon fibre to end-users TECNALIA and ACCIONA for further integration into 3D-printing applications and materials reinforcement initiatives.

CIRCE’s technology recovers fibres and oils from shredded wind turbine blades.