The SAFT-γ coarse graining methodology [E. A. Muller and G. Jackson, Ann. Rev. Chem. Biomol. Eng. ¨ 5, 405
(2014)] is used to develop force fields for the fluid-phase behaviour of binary and ternary mixtures comprising water,
carbon dioxide, and n-alkanes. The effective intermolecular interactions between the coarse grained (CG) segments
are directly related to macroscopic thermodynamic properties by means of the SAFT-γ equation of state for molecular
segments represented with the Mie (generalized Lennard-Jones) intermolecular potential [V. Papaioannou, T. Lafitte,
C. Avendano, C. S. Adjiman, G. Jackson, E. A. M ˜ uller, and A. Galindo, J. Chem. Phys. ¨ 140, 054107 (2014)].
The unlike attractive interactions between the components of the mixtures are represented with a single adjustable
parameter, which is shown to be transferable over a wide range of conditions. The SAFT-γ Mie CG force fields
are used in molecular-dynamics simulations to predict the challenging vapour-liquid and liquid-liquid fluid-phase
equilibria characterising these mixtures, and to study properties that are not accessible directly from the equation of
state, such as the interfacial properties. The description of the fluid-phase equilibria and interfacial properties predicted
with the SAFT-γ Mie force fields is in excellent with the corresponding experimental data, and of comparable if not
superior quality to that reported for the more sophisticated atomistic or united-atom models.