Vapor-liquid equilibrium and critical line of the CO2+Xe system. Critical behavior of CO2+Xe versus CO2+n-alkanes

An acoustic technique was applied to investigate the binary critical behavi or of the system CO2 + Xe. The critical line of this binary system exhibits a temperature minimum, suggesting the existence of azeotropic behavior. Th e compositions of the studied mixtures were chosen in order to define the m inimum temperature locus (p = 6.04 MPa, T = 282.34 K and at x(CO2) = 0.3622 ). The results were correlated with the Peng-Robinson equation of state usi ng conventional mixing and combining rules. Additionally, the same equation was used to correlate published data on CO2 with the five lower normal alk anes. The adjustable interaction energy and size parameters for CO2 + Xe ar e in line with these from CO2 + C2H6 up to CO2 + C5H12, while those for CO2 + CH4 deviate significantly.