Aspen Physical Property System - Physical Property Models

, where
� For polar, associating species:
, where
� For chemically bonding species:
Cross-Interactions
2 Thermodynamic Property Models 23
, with
, and
The previous equations are valid for dimerization and cross-dimerization if
these mixing rules are applied:
� = 0 unless a special solvation contribution can be justified (for example, i
and j are in the same class of compounds). Many � values are present in the
Aspen Physical Property System.
Chemical Theory
When a compound with strong association is present in a mixture,
the entire mixture is treated according to the chemical theory of dimerization.