The implementation of Sustainable Aviation Fuels (SAFs) in current and future long-haul aircraft to replace fossil-based kerosene represents the main path towards the decarbonization goal of the U.S. aviation industry by 2050. A deep and comprehensive characterization of the behavior of these new synthetic biofuels is a key to fulfill the strict regulations and standards and to ensure compatibility with existing propulsion systems in terms of performance, emissions, and safety. The present work focuses on the development of a Lagrangian-Eulerian thermodynamic framework to simulate SAF surrogates, employing the volume-translated Soave-Redlich-Kwong (VT-SRK) Equation of State (EoS) for accurate and efficient representation of thermodynamic properties. A novel computational fluid dynamics (CFD) solver, realFluidSprayFoam, was implemented within the OpenFOAM platform to account for high-pressure thermodynamics through real-fluid EoS-based departure functions and transport property corrections. This solver extends the application of real-fluid EoS to the Lagrangian phase, enabling precise modeling of multi-component liquid fuel mixtures via mixing rules. A new vapor-liquid equilibrium (VLE) based evaporation model of homogeneous droplets was developed and integrated into the solver to address the limitations of existing evaporation models, such as Raoult's law, under conditions near or beyond the critical point of SAFs. Validation was performed against microgravity experimental data for stationary heptane droplet evaporation at near- and super-critical conditions, demonstrating excellent agreement in evaporation curve slopes and droplet lifetimes. Further testing on multi-component SAF surrogates, showed strong agreement with high-fidelity Eulerian simulation data from the literature across various gas-turbine operating regimes. The preferential evaporation of volatile components and the corresponding impact on droplet lifetimes were effectively captured, highlighting the robustness and accuracy of the developed framework for high-pressure aerospace propulsion applications.@en