Two-phase equilibrium in binary and ternary systems X. Phase equilibria and compressibility of the systems carbon dioxide/propylene, carbon dioxide/ethylene and ethylene/propylene, and an account of the thermodynamic functions of the system carbon dioxide/propylene

Abstract

Abstract In the first section of the paper, P-V-T-x data for the systems carbon dioxide/propylene, carbon dioxide/ethylene and ethylene/propylene are presented and the phase-boundary data are discussed in terms of the laws of rectilinear diameters and corresponding states. In the second section, the thermodynamic properties of the carbon dioxide/propylene system are derived as accurately as possible, over a range of conditions including part of the critical region. For use in these calculations, suitable formulae are derived for evaluating the isothermal latent heats of the mixtures. It is found that the liquid mixtures obey the relation (U — U0)V = constant; a theoretical interpretation of this relationship is offered and, based on this theory, an equation is developed which is found to represent the variation of the enthalpy of the binary system carbon dioxide/propylene with volume and composition quite closely.