The 3R (recycling, recovery, and reuse) of fiber reinforced thermoset composites: paving the way for a circular economy

Abstract

The rising popularity of fiber-reinforced polymer (FRP) composites in the aerospace, automotive, and energy industries leads to waste management difficulties. This review critically considers 3R (recycling, recovery, and reuse) options for thermoset-based FRP composites, contrasting traditional (landfilling and incineration) and developing (solvolysis, microwave-assisted recycling, and catalytic) approaches. As the thermal recycling method leads to industrial recycling, it has a detrimental effect on the fibers’ characteristics and demands high energy input. Advanced solvolysis techniques, such as Fenton-based degradation, enable effective resin decomposition under mild conditions while retaining approximately 90% of the fiber strength. This review article emphasizes the practical applications of recycled carbon fibers (rCFs) in the automotive and aerospace industries, highlighting their economic as well as environmental benefits. Lifecycle assessments show that solvolysis is the most sustainable option, reducing greenhouse gas emissions by ∼30–50% compared to landfilling. The challenges of scalability, cost, and policy alignment are highlighted, along with future possibilities in hybrid recycling and advanced applications. This study proposes an outline for conveying FRP waste to a circular economy while balancing technical feasibility and industrial sustainability.