Ideal Adsorbed Solution Theory
Several theories have been developed in the last decades attempting to describe multicomponent adsorption. One of these theories, based upon classical chemical thermodynamic arguments, is Ideal Adsorbed Solution Theory (IAST) , .
Our research in this field has been a fruitful and successful enterprise with the Systems and Control Theory group of our institute (Prof. Dietrich Flockerzi).
This cooperation has led to the development of a robust generalized solution concept applicable to an N component system with nondecreasing single component adsorption isotherms .
The efficient solution method has also found successful application in more complex multicomponent adsorption models .
In order to test the application of the new solution method, a complex liquid chromatography system, where the single component adsorption isotherms display inflection points, has been chosen .
Graphical representation of the computed solution in the space (IAST Orbit) and three particular solutions cutting the IAST Orbit (Closure hypersurfaces). The calculation of this solution orbit is the core of the efficient approach proposed in .
Dynamic simulation of fixed-bed adsorbers
A very attractive feature of these achievements consists in overcoming time-consuming calculations by a sound mathematical understanding of the features of the IAST model. This results in robust and reliable implementations of the adsorption equilibrium computation for the dynamic simulation of liquid chromatography multi-column arrangements, e.g., SMB.
To this purpose, we implement suitable numerical schemes to solve the partial differential equations that describe fixed-bed adsorbers. We perform the necessary local adsorption equilibrium calculations with the efficient procedures described in  and .
This is one of several on-going topics within our research scope.