MOLECULAR SIMULATION OF THE VAPOR-LIQUID EQUILIBRIUM OF N2-NC5 MIXTURE BY MONTE CARLO SIMULATIONS

Abstract

ABSTRACT This study used Monte Carlo simulations in the Gibbs ensemble to describe the liquid-vapor phase equilibrium of nitrogen-n-pentane system for three isotherms. The study analyzed a wide range of pressures ranging up to 25 MPa. The system was modeled using the intermolecular potential Galassi-Tildesley for nitrogen and SKS for n-pentane. Results were compared against experimental data. Far from the critical point region, analyzed models reproduce favorably shape of the curve of phase equilibrium and in the vicinity of the critical point, results tend to move away from the experimental behavior. Critical points were determined (pressure, density and composition) for the three isotherms using an extrapolation method based on scaling laws, with satisfactory results. Calculated coexistence curves are adequate even if the models analyzed do not contain optimized binary interaction parameters .

Keywords

• Gibbs ensemble Monte Carlo
• vapor-líquid equilibrium
• critical point
• isotherms