High-Pressure Vapor-Liquid Equilibrium Computations Using the Hayden-O'Connell Method and Wilson Model
High-Pressure Vapor-Liquid Equilibrium Computations Using the Hayden-O'Connell Method and Wilson Model
Consider a binary mixture of -butanol and -butyl acetate. This Demonstration computes vapor-liquid equilibrium data for this mixture at various pressures. We use the Wilson model for the prediction of liquid-phase activity coefficients and the Hayden–O'Connell method to compute the gas-phase fugacity coefficients.
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This binary mixture presents a peculiar behavior: indeed, the azeotrope, which is present at low pressure ( -butanol at ), disappears at high pressures (e.g. at ).
76.85%mole
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14.69psi
50psi
The Demonstration plots gas-phase fugacity coefficients for user-specified values of the pressure (expressed in psi).
A comparison with the results obtained using ASPEN (http://www.aspentech.com/) for is also shown for both the equilibrium curve and the -value for -butanol (cyan dots come from ASPEN).
P=50psi
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In order to use the Hayden–O'Connell method, which takes into account deviations from ideal gas-phase behavior at moderate and high pressures, one has to compute second-order virial coefficients , , and or ) versus temperature. The Demonstration computes and plots these latter coefficients and compares the results obtained in the present study with the data (red dots) calculated by a Fortran program kindly provided by Professor J. P. O'Connell.
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11
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22
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12
B
21