An experimental and detailed kinetic modeling of the thermal oxidation stability of n-decane as a jet fuel surrogate component

Thermal oxidation stability of liquid jet fuels remains a significant scientific challenge in the development of modern aviation. This study aims at experimentally and numerically investigating the autoxidation of n-decane, which is used as a component of jet fuel surrogates in the literature. Induction periods (IP) of n-decane were measured in a PetroOxy device under 7 bar of oxygen and cell temperatures varying from 403 to 418 K. IPs give a quantitative measure of the oxidation stability of a fuel. In addition to IPs measurements, the total hydroperoxides content at the end of the IP test was quantified using two iodometric titration methods: colorimetry and potentiometry. In order to simulate the oxidation of the homogeneous liquid phase as a batch reactor, we developed a physical model based on the so-called gamma-phi thermodynamic approach to calculate the compositions of liquid- and gas-phases at the set temperatures and pressures. Based on a state-of-the-art method to capture solvent effects, a detailed kinetic model for the n-decane autoxidation was developed. The simulations are consistent with experimental data from this study (IP and hydroperoxides concentration profiles) and from the literature. The proposed model is validated to simulate the thermal oxidation stability of liquid n-decane, for conversions up to 15 %. Kinetic analyzes highlight the central role played by hydroperoxides decomposition and the self-termination of peroxy decyl (ROO.) radicals in the autoxidation of n-decane.

Automated summary

The thermal oxidation stability of liquid jet fuels is a major challenge for the aviation industry. This study focuses on the autoxidation of n-decane, a component of jet fuel surrogates, investigating it through both experimental and numerical approaches. The results reveal the quantitative measures of oxidation stability, such as induction periods and hydroperoxides content. A physical model and a kinetic model are developed to simulate the oxidation process and validate the model through experimental data.