Aspen Physical Property System - Physical Property Models

For an anionic component, we have
Molecular components
2 Thermodynamic Property Models 123
(29)
(30)
Applying Eq. 1, the normalization for molecular components can be done as
follows:
where �m lc,I is the activity coefficient of the molecular segment m contained in
component I,
Ionic components with symmetric reference state
(31)
(32)
Applying Eq. 10, the local composition contribution to the symmetric activity
coefficients for ionic components in multi-electrolyte systems can be
normalized as follows:
where I applies to all molecular components in the solution and Ix 0 is the ionic
strength at the symmetric reference state. In the case that electrolytes are
made up of only the conceptual 1-1 electrolyte segment and none of the
molecular segments, this reference state is equivalent to the molten state of
the conceptual 1-1 electrolyte.
(33)
(34)
(35)
Ionic components with infinite dilution aqueous solution
reference state
Applying Eq. 12, the unsymmetric activity coefficients for ionic components in
aqueous solutions can be normalized as follows:
(36)
(37)