Pyrolysis of aircraft cabin materials for chemical recycling

Increased usage of high-performance composite materials results in the necessity of novel routes of recycling for these materials. This article focuses on the application of pyrolysis for the recovery of potentially reusable carbon-based molecules from artificially aged aircraft components. Two different fractions of Ultem 1000-based components and one Nomex-based sample were pyrolysed, and the resulting chars, oils and gases were comprehensively characterised. Owing to the great heat resistance of the materials tested, the majority of the products obtained were chars and pyrolysis gases, and the proportion of condensable oils was very low. The condensates showed a highly complex composition, indicating their limited suitability for direct material recovery via pyrolysis oil utilisation under the investigated conditions. At the same time, the results provide insight into the decomposition behaviour of thermally stable polymers and highlight key constraints for the thermochemical treatment of such waste streams, including low condensable product yields, high product heterogeneity and the occurrence of halogen-containing species. Overall, this study identifies important limitations of direct pyrolytic recycling for these aircraft cabin materials and provides a basis for discussing alternative recovery strategies, process adaptations and design considerations for improved circularity.