Online course and simulator for engineering thermodynamics

CTP Lib thermodynamic properties server

CTP Lib is the library for calculating thermodynamic properties of the Center for Process Thermodynamics of the Ecole des Mines de Paris (Mines ParisTech).

CTP Lib is more general than TEP Lib, offering, in addition to the cubic EoS, models for representing associating fluids and / or formed of long molecules fluids , thanks to CPA and PC-SAFT equations of state.

Coupled to Thermoptim 2.5, it can calculate the properties of mixtures of real fluids, which the software cannot do itself.


We draw your attention to the fact that the use of these libraries requires a very good competence in fluid thermodynamics. It is necessary to choose a particular equation of state, and then define a whole set of parameters to characterize the pure components and mixtures thereof.

These choices must then be validated either experimentally or by comparisons with a reference software, otherwise the results provided by the model used may deviate significantly from reality.

In addition, CTP Lib includes only a limited number of equations of state and mixing rules, so it is not certain that it is adapted to model the fluid you are interested in.

This work of selection of thermodynamic model and its parameters can be tricky and is your sole responsibility.


You will find in this portal pages presenting firstly software packages for calculating fluid mixtures and secondly the thermodynamics of fluid mixtures.

We also refer you to the references below.

Ch. COQUELET, D. RICHON, Propriétés thermodynamiques, Détermination pour les fluides purs, Techniques de l'Ingénieur, BE 8 030

  Ch. COQUELET, D. RICHON, Propriétés thermodynamiques, Détermination pour les mélanges, Techniques de l'Ingénieur, BE 8 031

Install CTP Lib

Warning: The CTP Lib library is currently under development and will be officially deployed later. If you wish to participate in the tests, e-mail Renaud Gicquel.

To install CTP Lib, download the archive below and unzip it and follow these instructions:

  • replace your file with that of the archive if you do not use special external classes;

  • otherwise, load in your file the external class CTPlib.class included in the file from the archive, while respecting the internal structure of the archive;

  • place the bibCTP.jar and jdom.jar libraries in the installation directory of Thermoptim;

  • place in the mixtures directory the CTPlib.mix file and the folder CTPlib_MEL, which contain the list of systems considered and the data files that define them.

You can then start using these systems to create fluid mixtures, following the directions of section 2.6.2 "Creating an external mixture" of Volume 3 of the Thermoptim Reference Manual.

Documentation of use

You will find below a link to the documentation for using this library, including how to define the data files of external substances.

As stated in the documentation, the equation corresponding to the ideal gas Cp can be given in two forms. The spreadsheet below will convert the values of the DIPPR equation to polynomial values that can be integrated formally.

Finally, it is possible to create simplified (T, s) and (h, P) mixture charts using external class CreateMixtureCharts .


copyright R. Gicquel v2023.4

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