Binary VLE

Use this command to validate binary vapor-liquid equilibrium (VLE) or vapor-liquid-liquid equilibrium (VLLE) data for a given pair of components. The operation generates tables and plots of equilibrium K-values and fugacity coefficients versus liquid and vapor composition at a specified temperature or pressure. Any thermodynamic VLE K-value or VLLE K-value method may be used to validate the VLE or VLLE data.

For liquid activity thermodynamic methods, the K-values, liquid activity coefficient, vapor fugacity coefficient, vapor pressures and the Poynting correction are determined. For non-liquid activity method, such as equations of state or generalized correlations, K-values and liquid and vapor fugacity coefficients are determined.

Complete technical details may be found in topics under Utilities in the PRO/II Reference Manual.

This command does not interact with the flowsheet calculations in any way.

Usage

The window is opened by selecting the Binary VLE option from the Tools menu. Alternatively, you may push the button from the Toolbar. This window is only available when at least two components and a thermodynamic method have been selected.

First, select the required components for the equilibrium calculations from the drop down lists. Then select constant pressure or temperature operation and enter the value. By default, all plots will be generated. You may limit the number of plots by deselecting the appropriate check boxes. The options are:

XY Compositions: Vapor composition vs. liquid composition and temperature or pressure vs. liquid and vapor compositions.

Liquid Activity Coefficient: Activity coefficients or liquid fugacity coefficients vs. liquid composition.

K-values: Component K-values vs. liquid composition and component K-values vs. temperature or pressure.

You may select any defined thermodynamic system for the calculations from the drop down list.

Plots are generated by pressing the Calculate button. If Excel is selected on the Plot Setup option on the Options menu, tabular data are available in the spreadsheet. Otherwise, only the plots are shown.