Towards circular solutions: assessing environmental impact in aircraft cabin interiors through life cycle assessment

This study investigates the environmental impacts of aircraft cabin interiors, particularly focusing on plastics and composites, using Life Cycle Assessment (LCA) aligned with ISO 14040:2006 standards. It explores the full life cycle from raw material extraction to end-of-life, including recycling scenarios and integrating renewable energy sources. Utilising primary data from retired Airbus A320 and A321 aircraft, supplemented by extensive secondary data from recognised databases, the study examines carbon dioxide (CO₂) emissions, toxicity to freshwater ecosystems, and ozone depletion potential of various materials, notably carbon fibre-reinforced plastic (CFRP) and polyurethane (PU). CFRP is identified as a significant contributor to acidification and CO₂ emissions, due to its chemical-intensive production processes. Specifically, CFRP’s volume is only three times that of GFRP, yet its acidification emissions are 41 times higher. Furthermore, CFRP production is highly fossil-fuel-intensive, requiring nearly 997.4 MJ/kg, making it significantly more energy-consuming than aluminium or steel. In total, CFRP accounts for more than 45% of total CO₂ emissions, making it the largest contributor to climate change. Meanwhile, PU contributes 19% of total CO₂ emissions, releasing 5,760 kg CO₂ eq. PU is also noted for its greater toxicity to freshwater ecosystems, attributed to its petrochemical synthesis from isocyanates and polyols, which release toxic by-products harmful to aquatic environments even at low concentrations. Additionally, PU has a high ozone depletion potential due to its halogenated flame retardants, which can volatilise during manufacturing and ascend to the stratosphere, exacerbating ozone layer degradation.

The Circular Footprint Formula (CFF) were considered to evaluate the environmental benefits of recycling at different levels, suggesting that higher recycling rates can considerably reduce environmental burdens. Two recycling approaches were considered: full circularity (QSout = 1), where recycled materials are fully reused in aircraft production, and semi-circularity (QSout = 0.5), where recycled materials are repurposed in non-aviation industries. Findings reveal that using 40% or more recycled content significantly reduces CO₂ emissions, while landfilling emissions remain nearly identical to using only 20% recycled content, suggesting that low recycling rates may not be environmentally beneficial. Despite data limitations, the results indicate that increasing recycling rates beyond 20% is necessary for meaningful reductions in environmental impact.

The study also considers the effects of using renewable energy in aircraft cabin interior manufacturing. Findings show that a 1.6% increase in renewable energy during the manufacturing process of interior parts can reduce CO₂ emissions to just a quarter of current levels, underscoring the importance of transitioning to low-carbon energy sources in aerospace manufacturing. Overall, the study highlights the importance of enhancing the sustainability of aircraft cabin interiors through improved material choices, extended part longevity, and advanced recycling techniques. Through these findings, this project aims to advocate for a shift towards a circular economy within the aerospace sector to mitigate the substantial environmental impacts currently associated with the industry.