for the Revision, Extension and Further Development

of the Group Contribution Methods

UNIFAC, modified UNIFAC (Dortmund) and the

Predictive Equations of State PSRK and VTPR


The group contribution methods UNIFAC, modified UNIFAC (Dortmund) and the group contribution equations of state PSRK and VTPR are used world-wide for the synthesis and design of separation processes and a large number of further applications of industrial interest. They belong to the most important thermodynamic tools for the daily work of a chemical engineer and are therefore available in most of the commercial process simulators (e.g. Aspen Plus®, CHEMCAD™, Pro/II®, HYSIM, ProSim, Dynsim, ROMeo…).

Because there were no governmental funds available for a thorough revision, extension and further development of these methods, a company consortium was founded in 1996 at the University of Oldenburg to support the further development of these models. The aim of the consortium is the further development of the group contribution methods UNIFAC, modified UNIFAC (Dortmund), PSRK, and VTPR. Since the retirement of Prof. Dr. Jürgen Gmehling in April 2011, the UNIFAC consortium is maintained by DDBST.

The direct sponsoring by the companies even includes the possibility to influence the direction of further developments, so that the models will definitely become more and more attractive for the chemical industry.