Comparative life cycle energy analysis of carbon fibre pre-processing, processing and post-processing recycling methods

The use of carbon fibre reinforced polymers (CFRP) faces high energy consumption of carbon fibre production and a lack of recycling. Increasing the use of recycled carbon fibres (rCF) to substitute virgin carbon fibres (vCF) can improve the sustainability of the carbon fibre industry. Nonetheless, the most impactful area of CF recycling on the quality of recycled CFRP (rCFRP) is unclear. In this study, a life cycle energy analysis compares the Primary Energy Demand (PED) of an rCFRP automotive roof panel with different CF recycling methods in the pre-processing, processing and post-processing stage. Results indicate that retaining CF architecture during the pre-processing stage reduces the cradle-to-gate energy demand of an rCFRP roof panel by 26.3%. Fibre realignment in the post-processing stage leads to 11.4% higher cradle-to-gate energy consumption of an rCFRP roof panel, despite improvements in the stiffness of rCFRP. This study demonstrates the significant impact of the preprocessing and post-processing stages of CF recycling on the quality and production energy demand of rCFRP. Moreover, improvement in the architecture of rCF leads to a more significant conservation of energy during rCFRP component production than preserving the tensile properties of rCF.