Abstract

In the last decade, a great effort has been made to achieve a transition from the current linear economy to a circular economy. This transition also affects the composites sector, which, due to the intrinsic complexity of recycling, requires the implementation of recovery and remanufacturing processes that will be technically, economically and environmentally feasible. This challenge was addressed within the FiberEUse project, in which one of the working lines was based on waste recycling from wind and aeronautical sectors. Both glass and carbon fiber were recovered by pyrolysis. Subsequently, the recycled fiber was treated and processed with thermoplastic matrices used in automotive applications. The technologies used and the results obtained throughout the value chain, from the waste to the part, are presented in this paper. Formulations with different recycled fibers, with and without sizing treatments and with different matrices, were manufactured by compounding-injection. These materials were mechanically analysed and tested with the aim of selecting three formulations. The reinforced materials were validated in three real automotive prototypes: a pedal bracket, a front-end and a cowl top support. As a result, the prototypes were manufactured, tested and validated by the automotive companies.

Abstract

This paper presents the experimental validation of a thermal treatment technology to recover added-value substances from the plastic matrix of end-of-life wind turbine blades, when these are subjected to a pyrolysis process to recover the glass fibres. The experiments have been carried out in a laboratory installation consisting of two reactors in series, in which pyrolysis and thermal treatment of pyrolysis gases and vapours take place, respectively. The application of this treatment enables a 25 wt.% reduction in the production of pyrolysis liquids, increasing the production of gases in an equivalent way and without compromising the pyrolysis conditions to be used to recover the glass fibres. The two-phase liquids are converted into single-phase aqueous ones, while the hydrogen concentration in the gases increases from 4 % to almost 50 % in volume. This high concentration of hydrogen in the gases allows them to be used as a source of hydrogen for various applications. Consequently, the technology demonstrates that the plastic matrix of wind turbine blades can be valorised in a pyrolysis based recycling process.

Abstract

With fuel economy and lightweight design becoming ever more significant due to the current materials, resources and environmental crisis, the manufacture of polymer composites for automotive industry use has experienced a steady growth in the last years and is expected to keep growing in the coming years. This means that there is a vast range of different polymer composites available in the market, with their unique properties, manufacturing processes and materials imbedded in them, each with their own set of impacts on the environment throughout their whole life cycle. The end-of-life treatment of a composite determines a substantial fraction of its footprint on the planet, and advanced treatments, namely pyrolysis can be used to obtain high value added compounds such as hydrogen and other light fuels. This study aims to address and quantify the impacts associated with the manufacturing and end of life treatments of an experimental glass fibre mat reinforced thermoplastic composite and compare them with the impacts caused by materials currently used in the automotive industry. Life Cycle assessment methodology will be used to compare the environmental impacts of this new material with traditional glass fibre composites, natural fibre reinforced composites and other materials with similar mechanical properties.