Continuous thermodynamics approach for hydrogen solubility prediction

Abstract

Abstract Accurate characterization of heavy petroleum fractions remains challenging in hydroprocessing reactor modeling, where reliable hydrogen-solubility estimates in complex hydrocarbon mixtures are essential. Continuous thermodynamics has been successfully applied to represent crude oils and petroleum fractions in vapour–liquid equilibrium calculations through continuous composition distributions. Building on this framework, we propose a continuous-thermodynamics-based characterization methodology for vacuum gas oils and integrate it with the Augmented Grayson–Streed (AGS) approach to predict hydrogen solubility. Over temperature and pressure ranges of 459–653 K and 1.0–12.5 MPa, respectively, the proposed strategy reduces the global average absolute deviation with respect to experimental data from 22.5% to 11%. Beyond improving accuracy, the framework provides a systematic route to define a minimal set of pseudocomponents, reducing arbitrariness in heavy-fraction characterization while relying only on routinely measured laboratory data.