Aspen Physical Property System - Physical Property Models

General Pure Component Solid Heat
Capacity
The Aspen Physical Property System has several submodels for calculating
solid heat capacity. It uses parameter THRSWT/5 to determine which
submodel is used. See Pure Component Temperature-Dependent Properties
for details.
If THRSWT/5 is This equation is used And this parameter is
used
0 Aspen solid heat capacity CPSPO1
polynomial
100 or 102 DIPPR CPSDIP
200-211 Barin CPSXP1, CPSXP2, …,
CPSXP7
401 IK-CAPE heat capacity
polynomial
503 NIST ThermoML
polynomial
2 Thermodynamic Property Models 223
CPSPO
CPSTMLPO
The enthalpy, entropy, and Gibbs energy of solids are also calculated from
these equations:
Aspen Solid Heat Capacity Polynomial
The Aspen equation is:
Linear extrapolation occurs for Cp,i *,s versus T outside of bounds.
Parameter
Name
Applicable
Components
Symbol MDS Default Units
CPSPO1/1 Solids, Salts C 1i x — †
CPSPO1/2, ..., 6 Solids, Salts C 2i, ..., C 6i x 0 †
CPSPO1/7 Solids, Salts C 7i x 0 †
CPSPO1/8 Solids, Salts C 8i x 1000 †
† The units are TEMPERATURE and HEAT-CAPACITY for all elements. If any of
C4i through C6i are non-zero, absolute temperature units are assumed for
elements C1i through C6i. Otherwise, user input temperature units are
assumed for all elements. The temperature limits are always interpreted in
user input units.
Barin
See Barin Equations for Gibbs Energy, Enthalpy, Entropy, and Heat Capacity
for details about this submodel.
DIPPR
There are two DIPPR equations that may generally be used.
The more common one, DIPPR equation 100, is: