UNIFAC Consortium
Encyclopedia
The UNIFAC Consortium has been founded at the Carl von Ossietzky University of Oldenburg
at the chair of industrial chemistry of Prof. Gmehling
to invite private companies to support the further development of the group contribution method
s UNIFAC
and its successor modified UNIFAC (Dortmund). Both models are used for the prediction of thermodynamic properties, especially the estimation of phase equilibria.
The UNIFAC consortium is a successful example of private sponsorship of a public university in Germany.
and synthesis of chemical processes. Many companies doing process development in the field of chemical engineering
had announced their support for a new way to subsidize the further development. This is facilitated through the support of over 40 companies, and is particularly aided by the DDBST GmbH, which supplies the complete Dortmund Data Bank
(DDB) and several software tools for free. The DDB, a factual data bank for thermodynamic
data, especially phase equilibrium data, is the main source for the work of the consortium.
The consortium has e. g. added or modified 404 interaction parameters in the original UNIFAC matrix compared to the 635 parameters from the latest publication.
The major goals are to
The model parameters are confidential and only accessible to consortium members for at least two and a half year after the first delivery. After this time the university can publish the model parameters.
Both UNIFAC models are estimating activity coefficient
s, PSRK (short for Predictive Soave-Redlich-Kwong) however is a combination of the original UNIFAC model with an equation of state
.
Carl von Ossietzky University of Oldenburg
The Carl von Ossietzky University of Oldenburg is a university in Oldenburg, Germany. It is one of the most important educational facilities in northwestern Germany and specialises in interdisciplinary studies.- History :...
at the chair of industrial chemistry of Prof. Gmehling
Jürgen Gmehling
Jürgen Gmehling is a German professor for technical and industrial chemistry at the Carl von Ossietzky University of Oldenburg.-Biography:...
to invite private companies to support the further development of the group contribution method
Group contribution method
A group contribution method is a technique to estimate and predict thermodynamic and other properties from molecular structures.- Introduction :In today's chemical processes hundreds of thousands of components are used...
s UNIFAC
UNIFAC
The UNIversal Functional Activity Coefficient method is a semi-empirical system for the prediction of non-electrolyte activity estimation in non-ideal mixtures. UNIFAC uses the functional groups present on the molecules that make up the liquid mixture to calculate activity coefficients...
and its successor modified UNIFAC (Dortmund). Both models are used for the prediction of thermodynamic properties, especially the estimation of phase equilibria.
The UNIFAC consortium is a successful example of private sponsorship of a public university in Germany.
History
The consortium was founded in 1997 when the public financing of the further development of the models became unlikely. The models UNIFAC and mod. UNIFAC (Dortmund) have already been used widely in software for the simulationProcess simulation
Process simulation is used for the design, development, analysis, and optimization of technical processes and is mainly applied to chemical plants and chemical processes, but also to power stations, and similar technical facilities.- Main principle :...
and synthesis of chemical processes. Many companies doing process development in the field of chemical engineering
Chemical engineering
Chemical engineering is the branch of engineering that deals with physical science , and life sciences with mathematics and economics, to the process of converting raw materials or chemicals into more useful or valuable forms...
had announced their support for a new way to subsidize the further development. This is facilitated through the support of over 40 companies, and is particularly aided by the DDBST GmbH, which supplies the complete Dortmund Data Bank
Dortmund Data Bank
The Dortmund Data Bank is a factual data bank for thermodynamic and thermophysical data. Its main usage is the data supply for process simulation where experimental data are the basis for the design, analysis, synthesis, and optimization of chemical processes...
(DDB) and several software tools for free. The DDB, a factual data bank for thermodynamic
Thermodynamics
Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...
data, especially phase equilibrium data, is the main source for the work of the consortium.
Objectives
The normal work of the consortium includes- the creation of new and the improvement of older model parameters
- the measurement of experimental data (partly own work, partly given to contractors)
- holding annual member meetings
The consortium has e. g. added or modified 404 interaction parameters in the original UNIFAC matrix compared to the 635 parameters from the latest publication.
The major goals are to
- improve the quality of the predictions
- extend the range of applicability of the models. This include the support for further component types with new functional groups.
- supply the parameters to process simulation and DDB software (for consortium members only)
The model parameters are confidential and only accessible to consortium members for at least two and a half year after the first delivery. After this time the university can publish the model parameters.
Supported models
The UNIFAC consortium supports the development of three different models,- original UNIFAC,
- mod. UNIFAC (Dortmund), and,
- PSRKPSRKPSRK is an estimation method for the calculation of phase equilibria of mixtures of chemical components. The original goal for the development of this method was to enable the estimation of properties of mixtures which contain supercritical components...
(since 2005).
Both UNIFAC models are estimating activity coefficient
Activity coefficient
An activity coefficient is a factor used in thermodynamics to account for deviations from ideal behaviour in a mixture of chemical substances. In an ideal mixture, the interactions between each pair of chemical species are the same and, as a result, properties of the mixtures can be expressed...
s, PSRK (short for Predictive Soave-Redlich-Kwong) however is a combination of the original UNIFAC model with an equation of state
Equation of state
In physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
.