In this work, the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) and the Peng-Robinson (PR) cubic equation of state are coupled with the van der Waals-Platteeuw theory in order to calculate the hydrate phase equilibria for different pure gases, including CH4, C2H6, C3H8, iC4H10, CO2, N2, Ar, O2 and H2S, as well as representative binary, ternary and quaternary mixtures of these gases. Calculations for three-phase (Hydrate - Liquid water - Vapor; HLwV) equilibria are performed. The optimization of the Kihara ε parameter, through a fit to experimental data further improves the accuracy in correlating the hydrate equilibrium pressure for both models. Overall, it is shown that PR is more accurate than PC-SAFT for the prediction of clathrate hydrate equilibrium conditions for the systems considered.
- Peng-Robinson EoS
- Three-phase equilibria (HLV) modeling
- Van der Waals-Platteeuw theory