Modelling density and excess volume of hydrocarbon + water mixtures near the critical region

Abstract

Approaching the critical region of hydrocarbon + water mixtures will lead to an unusual increment in miscibility. In this research, CPA EoS is satisfactorily applied to predict the properties of three hydrocarbon + water mixtures at near/supercritical temperatures. First, CPA EoS is applied to evaluate the density of pure water and hydrocarbons in a range of pressure at various temperatures. To make a comparison on CPA models, both SRK and PR are accounted in the physical term of the model. In the case of pure hydrocarbons, the effect of volume shift correction (VS) on modeling results is also investigated. Afterwards, CPA EoS is used to predict the density of mixtures and relative volume change of mixing for hydrocarbon rich phase of mixtures at various temperatures. The results revealed that CPA EoS would be a reliable choice to predict complex behavior of hydrocarbon + water mixtures in a wide range of pressures and temperatures.