An innovative microfluidic reactor for testing the oxidation stability of fuels: application to a saf surrogate and comparison with the petrooxy test
Résumé
One potential solution to diminish the aviation carbon footprint is to blend Sustainable Aviation Fuel (SAF) into jet fuels. However, the thermal stability and oxidation stability of standard jetfuels may be affected by the addition of SAF 1 . In this context, we developed a Si-glass microfluidic reactor with a fluid supply made of inert polyether ether ketone (PEEK). The experimental rig PEEK-ACHU (Autoxidation µChip Heated Unit) was used to investigate the oxidation stability of a SAF surrogate and the results were compared to Induction Period (IP) measures, obtained in a standard PetroOxy device. A mixture of n-decane and iso-octane was used as the surrogate SAF 2 . The thermal oxidation stability of the mixtures was measured in the microreactor, working at conditions up to 453 K and 30 bar, with a gas-liquid segmented flow that allows the liquid oxidation to occur in homogeneous, self-agitated liquid slugs. PEEK-ACHU enables residence times as long as 3.8 hours to be reached on a 4-inch diameter Si/glass wafer, visual access to the reactor, and a well-defined kinetic study of the liquid fuel autoxidation. The total hydroperoxide (ROOH) concentration was quantified at the exit of the microreactor using a specifically designed HPLC device with a post-column reactor 3 . For comparison, the same analysis was conducted on the SAF oxidized in the PetroOxy apparatus, with the same residence time. The results of this study show that the microfluidic apparatus is able to perform reliable autoxidation measurements and allows a better understanding of the kinetics. The self-stirring ensures a homogenous phase, and the visual access of the reactor is relevant for other applications, such as spectroscopic monitoring of deposit formation.