The Principle of Corresponding States and Prediction of Gas-Liquid Separation Factors and Thermodynamic Properties: A Review

Abstract

A review is made of the development of the principle of corresponding states and the utility of the molecular shape factor method for the description of properties of pure fluids and fluid mixtures. From consideration of angle averaging of the potential energy of nonspherical molecules, shape factors were devised to relate the state of an acentric fluid with that of a reference fluid. With the development of correlations for the correspondence of states, an accurate equation of state of the reference fluid is made to apply to many fluids. The method is extended to mixtures with the introduction of van der Waals' combining rules. Extensive calculations show that the use of methane as the reference fluid yields useful results for paraffin hydrocarbons up to about C⁷, cyclic hydrocarbons of even higher molecular weight, and nonassociating polar substances. Diverse properties are examined including volumetric properties, vapor pressures, K-values, enthalpies, excess properties of mixing, and transport properties.