(181ag) High-Pressure Vapor-Liquid Equilibria for the Carbon Dioxide – Heptane – Dodecane

Experimental vapor-liquid equilibrium (VLE) measurements are reported for the ternary system carbon dioxide – heptane – dodecane at temperatures of (313, 343 and 373) K. The operating principle of the apparatus where VLE measurements were carried out is based on the static-analytic method; its main advantage is the on-line sampling via a ROLSI sampler-injector, a titanium alloy equilibrium cell and a gas chromatograph. Equilibrium ratios indicate a good internal consistency of the obtained data with an uncertainty less than 0.008 MPa, 0.02 K and 1% for the mole fraction composition in both phases. Separation factors obtained from experimental xi, yi mole fractions, indicate that heptane is feasible to be separated over dodecane at the three different temperatures. VLE was predicted using the Peng-Robinson Equation of State with the classical and Wong-Sandler mixing rules. Binary interaction parameters were obtained by correlating the VLE of the concerning binary systems reported in the literature.