title: Free Energy-Based Coarse-Grained Force Field for Binary Mixtures of Hydrocarbons, Nitrogen, Oxygen, and Carbon Dioxide.
abstract: The free energy based Lennard-Jones 12-6 (FE-12-6) coarse-grained (CG) force field developed for alkanes1 has been extended to model small molecules of light hydrocarbons (methane, ethane, propane, butane, and isobutane), nitrogen, oxygen, and carbon dioxide. The adjustable parameters of the FE-12-6 potential are determined by fitting against experimental vapor-liquid equilibrium (VLE) curves and heat of vaporization (HOV) data for pure substance liquids. Simulations using the optimized FE-12-6 parameters correctly reproduced experimental measures of the VLE, HOV, density, vapor pressure, compressibility, critical point, and surface tension for pure substances over a wide range of thermodynamic states. The force field parameters optimized for pure substances were tested on methane/butane, nitrogen/decane, and carbon dioxide/decane binary mixtures to predict their vapor-liquid equilibrium phase diagrams. It is found that for nonpolar molecules represented by different sized beads, a common scaling factor (0.08) that reduces the strength of the interaction potential between unlike beads, generated using Lorentz-Berthelot (LB) combination rules, is required to predict vapor-liquid phase equilibria accurately.
authors.affiliation: School of Chemistry and Chemical Engineering and Key Laboratory of Scientific and Engineering Computing of Ministry of Education, Shanghai Jiao Tong University , Shanghai 200240, China.
authors.forename: Fenglei
authors.initials: F
authors.lastname: Cao
authors.affiliation: School of Chemistry and Chemical Engineering and Key Laboratory of Scientific and Engineering Computing of Ministry of Education, Shanghai Jiao Tong University , Shanghai 200240, China.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Deetz
authors.affiliation: School of Chemistry and Chemical Engineering and Key Laboratory of Scientific and Engineering Computing of Ministry of Education, Shanghai Jiao Tong University , Shanghai 200240, China.|State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University , Changchun 130012, China.
authors.forename: Huai
authors.identifier: 0000-0002-0783-8194
authors.initials: H
authors.lastname: Sun
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry*; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014835:Volatilization
chemical_list: D006838:Hydrocarbons; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen