The UNIFAC Consortium
The UNIFAC Consortium is revising and extending the group contribution methods Modified UNIFAC (Dortmund), Original UNIFAC, Predictive Soave-Redlich-Kwong (PSRK), and, new in 2017, Volume-translated Peng-Robinson (VTPR).
The UNIFAC Consortium is a department of DDBST GmbH and not an independent organization; its staff is DDBST's staff and all contracts of the consortium sponsors are concluded with DDBST.
The consortium maintains its own web pages.
The work was focussed mainly on the further development of the modified UNIFAC (Dortmund) method and the consortium managed to double the number of available parameters and to improve the quality and reliability of the method to a really remarkable extent.
The current (consortium delivery 2017) interaction parameter matrix for modified UNIFAC (Dortmund) contains 6716 (6506 for 2016) parameters for 1790 (1730 for 2016) group pairs.
For comparison: The published parameter matrix for modified UNIFAC (Dortmund) contained 2670 parameters for 659 group pairs:
Jakob A., Grensemann H., Lohmann J., Gmehling J., "Further Development of Modified UNIFAC (Dortmund): Revision and Extension 5", Ind.Eng.Chem.Res., 45(23), 7924-7933, 2006
All the UNIFAC Consortium's work in a single diagram gives the following triangle:
The following animated diagram shows the yearly growth of interaction parameters from 1997 to 2017:
The next diagram contains the same information but the information about the revised and added parameter is color-encoded:
All the changes (new and revised parameter) for original UNIFAC are shown in the following diagram:
All the changes (new and revised parameter) for PSRK are shown in the following diagram:
All the changes (new and revised parameter) for VTPR are shown in the following diagram:
The group contribution equation of state model VTPR has been added as fourth supported model in the UNIFAC Consortium this year (2017). It is the successor of PSRK in many regards but will not replace PSRK, at least not yet. The developers of VTPR have tackled quite some weaknesses of PSRK and the UNIFAC Consortium is now busily building up the parameter base and the group assignments. The combination of an improved model and the creation of new interaction parameters plus an optimized group assignment scheme based on the current Dortmund Data Bank promises very precise, widely applicable, and reliable predictions.