A cost-effective alternative to radiocarbon analysis to assess the renewable carbon fraction in jet fuel samples

One of the major challenges in decarbonizing transportation is the gradual replacement of fossil-based aviation kerosene, specifically JET A1, with a sustainable alternative such as ASTM D7566-listed synthetic hydrocarbons. All approved sustainable aviation fuels (SAFs) have a specified maximum blending limit with fossil JET A1. Because SAFs and JET A1 have a similar hydrocarbon nature, the only currently available method for determining their content in blends with fossil kerosene is radiocarbon ( 14 C) analysis, which is costly and time-consuming. In this work, 48 kerosene samples, including JET A1 and four SAF types, HEFA (Hydroprocessed Esters and Fatty Acids), CHJ (Catalytic Hydrothermolysis Jet), SIP (Synthetic Iso-Paraffins), and AtJ (Alcohol-to-Jet), were comprehensively characterized using simulated distillation, GC × GC–MS/FID, and ATR-FTIR. Those analyses highlighted the differences between fossil-based JET A1 and SAFs. An alternative analytical approach to 14 C analysis was developed for HEFA content prediction, combining for the first time ATR-FTIR with a PLS (Partial Least Squares) chemometric model. This rapid method, which requires only one drop of sample, achieved RMSEP (Root Mean Square Error of Prediction) values below 1% ( V /V). The accuracy matched that of 14 C methods, providing impressive time and cost savings.