Saturated-Phase Densities of (CO₂ + Methylcyclohexane) at Temperatures from 298 to 448 K and Pressures up to the Critical Pressure

Abstract

This work reports saturated-phase densities for the CO 2 + methylcyclohexane system at temperatures between 298 and 448 K and at pressures up to the critical pressure. The densities were measured with a standard uncertainty of <1.5 kg• m −3 and were fitted along isotherms with a recently developed nonlinear empirical correlation with an absolute average deviation (Δ AAD ) of about 1.5 kg•m −3 . This empirical correlation also allowed the estimation of the critical pressure and density at each temperature, and the obtained critical pressures were found to be in close agreement with previously published data. We also compare both our density data and vapor−liquid equilibrium (VLE) data from the literature with the predictions from two models: PPR-78 and SAFT-γ Mie. The results show that densities were predicted better with SAFT-γ Mie than with PPR-78, whereas PPR-78 generally performed better for VLE. This could indicate that some of the unlike parameters of SAFT-γ Mie could be further optimized.

Measurements and Modelling of Vapour–Liquid Equilibrium for (H2O + N2) and (CO2 + H2O + N2) Systems at Temperatures between 323 and 473 K and Pressures up to 20 MPa

“…The description of the saturated-liquid density and the vapour pressure of pure nitrogen obtained with the estimated parameters is shown in Figure 8. One of the features of the SAFT-γ Mie equation is the accuracy to predict second-derivative properties, such as isobaric expansivity, isothermal compressibility and heat capacity, as was demonstrated in our previous work [77][78][79]. Figure 9 shows the SAFT-γ Mie prediction for the isobaric heat capacity and single-phase density.…”