Aspen Physical Property System - Physical Property Models

the pure fused salts. Applying Eq. 127, the system enthalpy and Gibbs free
energy with the unsymmetric reference state can be expressed as:
where and are the total enthalpy and total Gibbs
free energy of the solution calculated by the unsymmetric electrolyte NRTL
model at the limit of all molecular components approach zero, that is, the
pure fused salts state, and and are the
excess enthalpy and excess Gibbs free energy of ion i at the same limit
condition.
Applying Eq. 127, the system enthalpy and Gibbs free energy with the
symmetric reference state can be expressed as:
Comparing Eqs. 130 and 131 to Eqs. 128 and 129, we can get:
2 Thermodynamic Property Models 171
(132)
(133)
(130)
(131)
Therefore, the enthalpy and Gibbs free energy of ionic components with the
symmetric reference state can be written as:
(134)
(135)
(128)
(129)