CALCULATION OF JOULE-THOMSON INVERSION CURVES FROM A GENERAL CUBIC EQUATION OF STATE

The performance of a general cubic equation of state for Joule-Thomson inversion curve prediction is presented. A generalised inversion curve for the cubic equations of state, based on the GEOS, is proposed. The parameters m and alpha(c) of GEOS were estimated by the equal fugacity condition, using two sets of experimental data: temperature-vapour pressure-liquid density. In test calculations for Ar and CO2, the predicted VLE, the single phase densities (subcritical, critical and supercritical) as well as the Joule-Thomson inversion curve, are in good agreement with experimental data. A comparison with the predictions of the Soave-Redlich-Kwong (SRK), Peng-Robinson (PR) and Redlich-Kwong (RK) equations of state is also presented.