Life cycle assessment of glass fibre recovery from waste composites using pressolysis

Abstract

The increasing demand for sustainable solutions in composite recycling has driven the development of novel methodologies to minimise environmental impact. This study evaluates the life cycle assessment (LCA) of the pressolysis process for recycling glass fibres from waste composites, particularly from wind turbine blades. The pressolysis process called DEECOM®, initially developed for polymer filter cleaning, utilises repeated cycles of compression and decompression to separate fibres from polymer matrices.

Three scenarios are assessed: a batch process, an improved semi-continuous process with heat recovery, and a scaled-up semi-continuous process, targeting different schemes of scale-up. Results indicate that scaling up the pressolysis process significantly reduces environmental impact, with Global Warming Potential (GWP) dropping from 95 kg CO₂ eq/kg recovered fibre in the baseline laboratory scale batch process to 2 kg CO₂ eq/kg recovered fibre in the scaled-up scenario where component capacities are increased. This represents an approximate 98% reduction per kg fibre recovered in the scaled-up scenario compared to the baseline, with the most substantial improvement achieved by increasing equipment capacity rather than the number of runs or components. The environmental impact per kilogram of recovered fibre in the best scaled-up scenario studied (2.07 kg CO₂ eq/kg) approaches that of virgin glass fibre production and landfilling (1.72 kg CO₂ eq/kg), pyrolysis (1.52 kg CO₂ eq/kg) and solvolysis (1.92 kg CO₂ eq/kg), highlighting pressolysis as a promising recycling solution.

This study demonstrates the viability of pressolysis in facilitating a circular economy by reducing reliance on landfilling and virgin raw materials, contributing to a more sustainable composite material lifecycle.