A COMPUTER PROGRAM FOR THE CORRELATION OF BINARY VAPOR-LIQUID EQUILIBRIA DATA Jacob H. Lashover Tulane University, New Orleans, Louisiana January 2, 2015 Abstract: This FORTRAN program was used to correlate the binary vapor-liquid equilibria (VLE) systems which were used to build the representations of the multicomponent systems for calculations in Monte Carlo Marching. The Redlich-Kister (R-K) activity coefficient model was chosen for this work although other models such as Wilson, Margules, van Laar, etc. could also be used when non-electrolytic systems at low to moderate pressures are considered. The Taylor series was used as a linearization and convergence technique to solve the simultaneous, non-linear equations which are encountered when binary VLE data are fitted using a least-squares criterion. Pressure-liquid composition, vapor composition-liquid composition, and temperature-liquid composition data, optionally weighted with the Gilmont method, were correlated using the 3 rd order R-K equations to relate activity coefficients to liquid composition. Computer output consists essentially of equilibrium composition curves and the B and C constant for each binary pair which are used as inputs to calculate VLE for multicomponent systems. Future work will show the replacement of this program with one using Monte Carlo Marching and programmed in QB64. Derivatives of the R-K equations will not be required thus facilitating the addition of the Wilson, van Laar, Margules and other activity coefficient models. The original work was first published at the