Retrieving Thermodynamic Properties

[nrgeng]

Recently I used the Flowsheet Calculator (Property Type) to obtain the enthalpy for carbon monoxide at 25 C and 1 atm. The value displayed as -0.0087962109 kJ/mol. The expected value was -110.5 kJ/mol from the literature.

The Flowsheet Calculator (Constant Type) displays enthalpy of formation as -110.530 kJ/mol for the Peng Robinson Model Set.

When Property enthalpyF is displayed, the value is -110.5388, which is Property Type enthalpy, -0.00879, plus Constant Type EnthalpyOfFormation, -110.530. This is understandable.

My question is what is the Property gibbsEnergy? I have a guess.

From COCO Help Entry
Gibbs free energy
"If TEA's internal calculation routines for enthalpy and entropy are used, the Gibbs energy will not include the formation terms (heat of formation and entropy of formation)."

Gibbs Energy (Forum 18Mar 16).png (10.08 KiB) Viewed 7347 times

Is this correct? Thanks for any information on this.

[jasper]

Formation terms are not included in TEA's Gibbs energy, it is H - T * S.

If you want Gibbs energy with formation terms, please follow the route EnthalpyF - T * EntropyF.