Oxidative stability and molecular degradation of aviation fuels characterized by Raman spectroscopy

The increase in the production of Sustainable Aviation Fuels (SAFs) is essential to promote the decarbonisation of the aviation sector by 2050. In this study, Raman spectroscopy was used as a tool to investigate structural changes in samples of JET A-1, Farnesane, and a 10 % Farnesane blend with JET A-1(designated FarnJET10), exposed to an oxidative atmosphere for 3, 24, and 48 h. The results show that JET A-1 exhibits higher oxidative stability, while Farnesane is prone to degradation, with a rapid decrease in vibrational band intensity across all regions of the spectrum. The FarnJET10 blend exhibited intermediate oxidative behaviour, but the findings indicate that the presence of Farnesane compromises the stability of JET A-1. Principal Component Analysis (PCA) was applied to distinguish the stability and chemical behaviour of the fuel samples. The first two principal components explained 98.91 % of the total spectral variation, with PC1 and PC2 accounting for 85.44 % and 13.47 %, respectively. The PCA scores demonstrated a clear separation between the pure fuels and the blend, highlighting the distinct oxidative responses and structural changes induced by exposure to an oxidising atmosphere. These findings highlight the oxidative vulnerability of the SAF/fossil fuel blend and its effects on fuel stability, which may compromise performance during storage and operational use in aviation systems.