FuelLib: Jet Fuel Library

NREL's FuelLib is an open-source, Python-based jet fuel library that estimates the thermodynamic and transport properties of hydrocarbon fuels.

Leveraging the group contribution method, FuelLib predicts fuel properties over a wide temperature range based on the molecular structure and weight percentages of individual compounds or compound families in the fuel.

FuelLib represents multicomponent fuels by assigning reference compounds to each hydrocarbon family—n-alkane, iso-alkane, cyclo-alkane, and aromatic—and carbon number. Fundamental properties, such as boiling point and critical temperature, are calculated at standard conditions for each compound and are then used in component-wise correlations and mixing rules to predict thermophysical properties at both the component and mixture levels.

Application in Aviation Fuel Research

Aircraft engines must deliver high power and energy density under harsh conditions while also meeting stringent requirements for system robustness, safety, and reliability. To achieve this, they rely on fuels that meet strict property requirements; this is especially true for synthetic aviation turbine fuels (SATFs), which are not made from petroleum. The properties of SATFs affect liquid fuel atomization and vaporization, which in turn impact flame stabilization and pollutant formation from aviation gas turbine combustors.

Accurate property prediction is essential for assessing the viability of new SATF pathways through combustor simulations, especially since the fuels are complex mixtures for which measurements under relevant conditions may not be practical.

NREL's FuelLib enables property estimation without detailed molecular composition data, making it particularly useful for complex fuel mixtures where detailed experimental characterization of fuel composition is unavailable. The tool supports accurate property estimation for new SATF pathways based on compositional measurements using the group contribution method.

Development Team

The development team includes Shashank Yellepantula, David Montgomery, and Bruce Perry.

Publications

Developing Open-Source Tools for Increasing the Efficiency of Synthetic Aviation Turbine Fuel Certification Process, NREL Technical Report (2025)

Contacts