A recent development on the Modified UNIFAC (Dortmund) model was the introduction of several new flexible main groups. The introduction of the major part of the new groups was scheduled in cooperation with our consortium members, so that the great number of components, which can only be treated with the help of the new group interaction parameters, are of major industrial interest.

Typical results are given for the following new Modified UNIFAC (Dortmund) main groups:

With the enlargment of the database sometimes it is observed, that the already existing group interaction parameters can be improved since the temperature, pressure and concentration range covered by the new data is out of the range where the parameters have been fitted before. A great part of parameters were fitted between 1985 and 1993. During this time no data bank for solid-liquid equilibria and only few h^E-data at high temperatures were available.

Typical results are given for the following revised Modified UNIFAC (Dortmund) main groups:

In the moment the focus of the ongoing work is the further development of groups containing sulphur like Thioles, Sulfides and Sullfolanes. Some typical results for different sulphur main groups can be seen in the following figures.