Experimental measurement and thermodynamic modeling of phase equilibria of {CO2 + tetralin + n-alkanes (with n=6, 16)} and its binary systems

Abstract

This work measured data of binary mixtures {CO2 + n-hexane}, {CO2 + tetralin}, {CO2 + n-hexadecane} at high pressure, {tetralin + n-hexadecane} system at low pressure, and the ternary systems {CO2 + n-hexane + tetralin} and {CO2 + tetralin + n-hexadecane} at high pressures. Two experimental methodologies were used: synthetic static method and analytical dynamic method. The data obtained at high pressure were used to determine the binary interaction parameters using the Peng-Robinson equation of state and classical mixing rules. Regarding the low pressure data, the binary interaction parameter for the {tetralin + n-hexadecane} system was predicted by literature correlations and adjusted to correlate our experimental data. The binary parameters were also used to predict the behavior of the ternary systems {CO2 + n-hexane + tetralin} and {CO2 + tetralin + n-hexadecane} at high pressures. The model did not predict so accurately the bubble and dew pressures for the ternary systems at high temperatures and elevated CO2 compositions using the parameters obtained from binary systems but the results were reasonable compared to experimental results.