Upload
jacob-h-jack-lashover
View
46
Download
1
Embed Size (px)
DESCRIPTION
This program was used to correlate the binary vapor-liquid equilibrium (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, are correlated using the 3rd 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. All of the distillation columns for Union Carbide’s Sevin© process were designed using VLE correlations from this program. Pressure-liquid composition data was obtained from the equilibrium pressure of cylinders, in a constant temperature bath, into which the components were injected by weight to avoid exposure to personnel.
Citation preview
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 3rd 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
November, 1962 meeting of the American Chemical Society in
Gatlinburg, Tennessee where Dr. Edward Teller presented some of his
work in the same group of papers. The author was privileged to be
selected to participate in a panel discussion which included Dr. Teller.
All of the distillation columns for Union Carbide’s Sevin©
process were designed using VLE correlations from this program.
Pressure-liquid composition data were obtained from the equilibrium
pressures of cylinders, in a constant temperature bath, into which the
components were injected by weight to avoid exposure to personnel.
Keywords: Vapor-liquid equilibrium, Taylor series, convergence,
simultaneous non-linear equations, multicomponent systems