The Thermodynamics of Fluid-Phase Benzene via Molecular Simulation

Accurate values for thermodynamic properties throughout the fluid phase are a requirement for the design of separation processes. To date, very few pure substances have been completely characterized because of time and monetary constraints. Low cost computing power now permits complete determination of the thermodynamic properties of pure substances via molecular simulation. Molecular simulation is computational statistical mechanics. Benzene is an important industrial chemical and pharmaceutical precursor. It is the prototypical, symmetric, hexagonal molecule and is an ideal candidate for molecular simulation. The molecular models of three researchers in the field are submitted for Monte Carlo simulation in the virtual laboratories at All claim that their models best represent real benzene. The MC code used for experimentation measures 12 thermodynamic properties with associated errors, and derivatives of the residual Helmholtz energy with respect to density and temperature to order 4. The thermodynamic properties are used to generate a multiparameter fundamental equation of state that represents the model throughout the fluid phase. Thermodynamic properties from the three models are compared to the values from the Goodwin equation of state for benzene. A single model is chosen as the best representative of real benzen