A Physically Based Parametrization Methodology for Hydrogen Using the PC-SAFT EoS To Predict Vapor–Liquid Equilibria of Hydrogen–Hydrocarbon Mixtures

Accurate prediction of hydrogen–hydrocarbon vapor–liquid equilibrium (VLE) is important for hydrogen technologies. Conventional PC-SAFT hydrogen parametrization relies on cryogenic saturation data, limiting its relevance to engineering conditions. Moreover, hydrogen parameter sets with comparable pure-fluid accuracy can yield different mixture predictions. This work proposes a physically based methodology that fixes hydrogen dispersion energy using independent intermolecular-potential information and regresses the remaining parameters to supercritical hydrogen density data. A temperature-dependent binary interaction parameter derived from hydrogen + n-heptane VLE is applied without system-specific refitting to mixtures with n-alkanes, 1-alkenes, cycloalkanes, and aromatics. The methodology achieves an overall average bubble-point pressure deviation of approximately 4.2%, with variations among hydrocarbon families, and improves cross-system applicability compared with two literature hydrogen parameter sets. Predictions are generally comparable to UMR-PRU and PPR78 results, with improved agreement for selected systems and conditions.