Prediction of solid–fluid phase diagrams of light gases–heavy paraffin systems up to 200 MPa using an equation of state–G E model

Abstract

This paper presents a procedure for the simultaneous prediction of fluid–fluid and solid–fluid equilibria of light gases–heavy hydrocarbons systems under pressure. The fluid phases behaviour is described by the modified LCVM, an equation of state–G E model and the solid phase non-ideality is represented by the Wilson equation using the predictive local composition concept. This procedure was tested for several binary and ternary systems as well as multi-component systems leading to a good representation of both fluid–fluid and solid–fluid equilibria with a typical average absolute deviation of 1.5 K for the solid–fluid phase boundary of binary and ternary mixtures and of 0.5 K for multi-component systems. The AAD% in the fluid–fluid phase boundary of multi-component systems is of 3.2%.