The interfacial properties of water/oil mixtures is a topic of significant interest for the oil and gas and chemical industry [1-3]. However, the reported experimental data at high temperatures and pressures are scarce. Our study focuses on simulating the interfacial tension of binary mixtures of water with toluene and n-dodecane, and the ternary water/toluene/n-dodecane) at elevated temperatures ranging from 383.15 to 443.15 K. Molecular Dynamics simulations with atomistic molecular models, developed primarily for biomolecular systems were employed. Our attempts focused on incorporating and benchmarking the performance of these well-established atomistic force fields in systems of interest to the chemical/petrochemical industry. In the simulations performed, the effects of the water model and the scaling of interatomic interactions by introducing a binary interaction parameter were assessed for the accurate reproduction of experimental data [4]. The combination of the TIP4P/2005, SPC/E and TIP3P water models with the GAFF and LIPID14 force fields for toluene and n-dodecane respectively, coupled with appropriate binary interaction parameters for the interaction of carbon with oxygen atoms were found to yield accurate results in the case of binary mixtures. For the water/toluene/n-dodecane mixture, all force field combinations tested resulted in overestimated IFT values for the whole range of state points examined. Our simulations show that these widely used force fields, originating from the world of biomolecular simulations, are suitable candidates in the study of binary water/oil mixtures.
[1] N.K. Rastogi, K.S.M.S. Raghavarao, V.M. Balasubramaniam, K. Niranjan, D. Knorr, Crit. Rev. Food Sci. Nutr., 47 (2007) 69-112.
[2] J.S. Eow, M. Ghadiri, Chem. Eng. J., 85 (2002) 357-368.
[3] K.S. Pedersen, P.L. Christensen, Phase behavior of petroleum reservoir fluids, CRC/Taylor & Francis, Boca Raton, 2007.
[4] Industrial Fluid Properties Simulation Collective, http://fluidproperties.org, accessed March 14, 2017.
