Panagiotopoulos-Reid mixing rule

It is interesting to note that for the systems carbon dioxide with n-butanol and with n-octane, the optimal values of the two-parameters ky and kj are quite close to each other. Use of the conventional mixing rules for these simple systems would result in almost as good agreement between experiments and predictions as for the two-parameter correlation. However, for biomaterials, the Panagiotopoulos Reid mixing rules improves the prediction of the phase behavior appreciably. 

Fig. 14.7 Partitioning behavior for the system CO2-H2O-MMA calculated with the Peng-Robinson eos and Panagiotopoulos-Reid mixing rule at different temperatures.

In summary, from an extensive comparison of the calculations with the experimentally obtained results [40], it can be concluded that the phase behavior of the ternary system MMA-H2O-CO2 can be quahtatively predicted by the Peng-Robinson equation of state in combination with the Panagiotopoulos-Reid mixing rule. In general, more experimental data are required concerning the binary systems for a better optimization of the interaction parameters. To obtain a more quantitative description of the phase behavior, especially close to the critical point, a more rigorous approach such as the SAFT-VRX model [46, 47] can be used. 

Figure 4. Three-phase equilibrium LtL2V in the system carbon dioxide-water-1-propanol at 333 K and 13.1 MPa exp., this work — Calculated with Peng-Robinson EOS using Panagiotopoulos and Reid mixing rule, left side prediction from pure component and binary data alone, right side interaction parameters fitted to ternary three-phase equilibria at temperatures between 303 and 333 K...

Figure 1 VLB data of methyl oleate in SC-CO2 at 70 C as calculated with Peng-Robinson equation of state with conventional and Panagiotopoulos and Reid mixing rules compared with experimental data.

Panagiotopoulos A.Z., Reid R.C., "A new mixing rule for cubic equations of state for highly polar, asymmetric systems", in... 

Due to restriction for space the results on modeling the high-pressure phase behaviour of the system carbon dioxide-water-1 -propanol are presented only briefly. The model used in this work was the Peng-Robinson EOS [8] with an temperature dependent attractive term due to Melhelm et al. [9], Although several mixing rules have been tested, the discussion will be restricted to the two-parameter mixing rule of Panagiotopoulos and Reid [10],... 

Panagiotopoulos, A. Z., and Reid, R. C., 1986. New mixing rules forcubic equations of state for highly polar asymmetric mixtures. ACS Symposium Series 300 American Chemical Society, Washington, D.C., pp. 571-582. 

Panagiotopoulos AZ, Reid RC. New mixing rule for cubic EOS for highly polar, asymmetric systems. ACS Symp Ser 1986 300 571-582. 

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