Multicomponent Vapor-Liquid Equilibria Computation

摘要

The report is concerned with the development of a comprehensive computer program for the estimation of multicomponent vapor-liquid equilibria in two phase systems at low to moderate pressures. The system which was developed is referred to as 'the KVALUE routines.' The KVALUE routines consist of approximately 2,000 FORTRAN instructions which require 21,454 words of storage when loaded into an IBM 360/44. Included in the text discussion are the following topics: the thermodynamic criteria for equilibrium, the computation of vapor phase fugacity coefficients using both the virial and the Redlich-Kwong equations of state, the correlation of activity coefficients to liquid phase composition via the equations of Wilson, Van Laar, and Hildebrand, the calculation of standard-state fugacities from thermodynamic considerations and from the popular Chao-Seader correlation, and techniques for evaluating the necessary physical properties and parameters. Also included is a discussion of Marquardt's method and the manner in which this algorithmic process is implemented to obtain a solution to the system of nonlinear equations which must be solved when estimating multicomponent vapor-liquid equilibria. (Author)