Thermodynamics

Henry's Law: Activity coefficient option

When you use Henry’s Law in Fluid Types that use the Non-Random Two-Liquid (NRTL) method as the selected System method, you can now include the activity coefficients in the phase equilibrium calculations for selected Henry’s solutes.

Previously, you could include the activity coefficients in the phase equilibrium calculations for Henry’s solutes only for Fluid Types that used the Electrolyte NRTL (eNRTL) method as the selected System method.

Use the Include activity coefficient in liquid fugacity for Henry’s solutes (select for solutes in Component List) checkbox in the Equilibrium Options section of the Fluid Editor to turn on or turn off the option to include the activity coefficient in the phase equilibrium calculations for each Henry’s solute in the Fluid Type. You can see this checkbox only when you also select the Use Henry’s Law (select solutes in Component List) checkbox.

When you select the Include activity coefficient in liquid fugacity for Henry’s solutes (select for solutes in Component List) checkbox, the Activity column appears in the table in the Component List section of the Fluid Editor. The Activity column includes a checkbox for each defined Henry’s solute (selected Henry checkbox) in the Fluid Type.

Use the Activity checkbox in the Component List section to determine whether the phase equilibrium calculations for the corresponding Henry’s solute include the activity coefficient.

Refer to "Equations for the NRTL method" in the AVEVA Process Simulation Thermodynamics Reference Guide for more information.

Henry's Law: Pressure correction option

When you use Henry’s Law in your Fluid Types, you can now include a pressure correction (like the Poynting correction) in the calculations for the Henry’s coefficients.

Previously, you could use the pressure correction only for Fluid Types that used the Electrolyte NRTL (eNRTL) method as the selected System method. You can now use the pressure correction with the following liquid activity coefficient (LACT) methods:

• Non-random two-liquid (NRTL)

• Universal quasi-chemical (UNIQUAC)

• UNIQUAC functional-group activity coefficient (UNIFAC)

• Wilson

  Use the Apply Henry’s Law Pressure Correction using Brelvi O’Connell Model checkbox in the Equilibrium Options section of the Fluid Editor to determine whether the Henry’s coefficient calculations include the pressure correction. You can see this checkbox only when you also select the Use Henry’s Law (select solutes in Component List) checkbox.

  Refer to the section for the corresponding method in the AVEVA Process Simulation Thermodynamics Reference Guide for more information about how the Henry’s coefficient calculations change based on the checkbox selection.

Henry's Law: Rigorous mixing option

When you use Henry’s Law in Fluid Types that use the NRTL method as the selected System method, you can now use the rigorous mixing rule to calculate the Henry’s coefficients in mixed solvent.

Previously, you could use the rigorous mixing rule only for Fluid Types that used the Electrolyte NRTL (eNRTL) method as the selected System method.

Use the Include rigorous mixing with activity coefficient and critical volumes for Henry’s Law checkbox in the Equilibrium Options section of the Fluid Editor to determine whether the Henry’s coefficient calculations use the rigorous mixing rule. You can see this checkbox only when you also select the Use Henry’s Law (select solutes in Component List) checkbox.

Refer to "Equations for the NRTL method" in the AVEVA Process Simulation Thermodynamics Reference Guide for more information.