MEASUREMENT AND PREDICTION OF THE BUBBLE DEW-POINT LOCUS IN THE NEAR-CRITICAL REGION AND OF THE COMPRESSED FLUID DENSITIES OF THE METHANE CARBON-DIOXIDE N-BUTANE TERNARY-SYSTEM

The bubble/dew point locus in the near-critical region, the critical p oints and the compressed fluid densities of two ternary mixtures of th e methane-carbon dioxide-n-butane system were measured in a ROP comput er-controlled, mercury-free, high-pressure PVT system. The Soave-Redli ch-Kwong (SRK) and Patel-Teja (PT) equation of state (EOS) coupled wit h different mixing rules were used to predict the experimental VLE dat a. The average absolute deviations between the predicted and experimen tal bubble/dew point pressures were less than 2.5 for all the models t ested. The PT EOS and the volume-translated SRK EOS proposed by Penelo ux and Rauzy [Peneloux, A. and Rauzy, E., 1982. A consistent correctio n for Redlich-Kwong-Soave volumes. Fluid Phase Equilibria, 8: 7-23] we re used to predict the compressed fluid densities, giving satisfactory results.