Abstract: Based on the experimental results, this paper puts forward a thermodynamic model for prediction of was precipitation in gas condensate mixtures. The model regards the process of wax precipitation as that of multi-solid phase precipitations. The precipitated wax composed of a number of solid phases, and each phase is made up of a pseudo-component, without any mixture among the solid phases. Accordingly, this paper proposes a vapor-liquid-multi-solid material balance equation. Integrated with the empirical equation for calculation of solution heat in condensate system and the multi-solid flash numerical algorithm, this model can be applied to quantitative simulation and estimation of the wax precipitation amount, obtaining vapor-liquid parameters by using equation of state. The estimation results show that the wax precipitation amount and related temperature given by the model are in good agreement with the experimental data for the condensate hydrocarbon mixtures.

Key words: wax, thermodynamic equilibrium, model, condensate