The excess function formalism was used to represent the solid-fluid equilibrium of binary systems formed by carbon dioxide and heavy hydrocarbons. The model is based on the Peng-Robinson equation of state, extended to represent the PVT properties of pure components, and the Peneloux excess function formalism to represent the solid-fluid equilibrium properties of mixtures. The results show that the effect of density on the excess term should be taken into consideration in the calculations for CO2/heavy hydrocarbons systems. This effect is particularly important in the vicinity of the gas critical point.