Discrete Thermodynamics

Biobased components are posing a challenge to thermodynamic description because of their many functional groups in each molecule resulting from the high oxygen content of biomass. For fossil-based chemicals on the other hand, each functional group has to be introduced by a dedicated reaction step resulting in typically one or at most two functional groups per molecule. The currently available thermodynamic models thus allow describing preferably molecules of low functionality. Especially the situation, in which several functional groups between two neighboring molecules are simultaneously interacting, strong non-idealities are to be expected. To account for these, the full three-dimensional nature of the molecular interactions needs to be taken into account.

The three dimensional thermodynamics realized in the MOQUAC will be combined with the approach of discrete thermodynamics in cooperation with Ass. Prof. Dr. Thomas Wallek at TU Graz. Discrete thermodynamics allows accounting for the dedicated environment of a molecule. This approach has been applied to lattice systems in the past, comparing it successfully to the results of Monte-Carlo molecular simulations. This is currently joined with the ideas of MOQUAC previously derived.

Publications

• T. Wallek, M. Pfleger, A. Pfennig, 2016: Discrete Modeling of Lattice Systems: The Concept of Shannon Entropy Applied to Strongly Interacting Systems. 
• R. Bronneberg, A. Pfennig, 2013: MOQUAC, a new expression for the excess Gibbs energy based on molecular orientations. 
• R. Bronneberg, A. Pfennig, 2011: Improvement of the UNIQUAC combinatorial-entropy term by adjusting the standard segment. 
• G.H. Ehlker, A. Pfennig, 2002: Development of GEQUAC as a new group contribution method for strongly non-ideal mixtures.

Contact(s) : Andreas Pfennig