Comparing Life Cycle Energy and Global Warming Potential of Carbon Fiber Composite Recycling Technologies and Waste Management Options

TLDR

Carbon‑fiber reinforced polymers are increasingly produced—over 140,000 t annually by 2020—creating waste that demands sustainable, energy‑efficient treatment. The authors applied a life‑cycle assessment using literature data, process models, and experimental work to quantify primary energy demand and global warming potential. Recycling outperforms landfill and incineration, with advanced processes achieving GWP reductions of 19–27 kg CO₂eq kg⁻¹ and PED savings of 395–520 MJ kg⁻¹, though benefits depend on how recycled fiber displaces virgin material.

Abstract

Carbon fiber reinforced polymers (CFRP) are used in increasing quantities as they have some of the best properties in terms of specific strength and stiffness of any widely available material. By 2020, annual global CFRP production is expected to be over 140,000 tonnes. However, the resulting increased quantity of CFRP waste has highlighted the need for sustainable treatment options as carbon fiber manufacture has high-energy intensity. A life cycle assessment methodology is used to evaluate primary energy demand (PED) and global warming potential (GWP) leveraging best available literature data, process models, and experimental work. Overall results indicate that recycling scenarios are generally the environmentally preferable options over landfill and incineration. However, the relative environmental benefits of advanced recycling processes (i.e., pyrolysis, fluidized bed, and chemical recycling process) depend on the method used to determine displacement of virgin carbon fiber by recycled carbon fiber. Totally, recycling processes can achieve a representative GWP from −19 to −27 kg CO2eq and PED from −395 to −520 MJ per kg CFRP, providing superior environmental performance to conventional composite waste treatment technologies.