Chain fluids: Contrasts of theoretical and simulation approaches,and comparison with experimental alkane properties

摘要

In this work, we undertake a fundamental comparison of analogous lattice and continuum integralequation theories, with both held accountable to the results from Monte Carlo simulation and realexperimental data on short chain molecules. Each integral equation method is applied to determinethe system's microscopic intermolecular site-site distributions and the corresponding bulkthermodynamic properties. These properties and those from the MC simulations are then fitted tocorresponding data on n-alkanes. Thus, in side-by-side comparisons we cover a number offundamental contrasts: theory versus simulation, lattice-based theory versus continuum-basedtheory, and thermodynamic properties.of model chain molecules versus the actual experimentalproperties of hydrocarbons. The observed behavior of the modeling methods is compared in termsof both the experimentally accessible physical properties (e.g., PVT and coexistence properties) andthe more fundamental underlying quantities, such as free energies and model internal energies. Wealso discuss the various options for model parametrization and subsequent impact on the predictedphysical properties. The results from this work are used (alone, with no additional fitting) in thearticle which follows, wherein we predict the experimental properties of alkane mixtures.