ISBN 9783843917766

978-3-8439-1776-6, Reihe Thermodynamik

Thomas Reschke
Modeling and Design of Aqueous Two-Phase Systems (Band 11)

168 Seiten, Dissertation Technische Universität Dortmund (2014), Softcover, A5

Zusammenfassung / Abstract

In the area of highly specific drugs, biopharmaceuticals (e.g. therapeutic proteins) take up a substantial proportion of sales on the world market. In the production of biopharmaceuticals, high amounts of total production costs originate from downstream processing. The extraction in aqueous two-phase systems is a promising strategy to enable a more cost effective purification of biopharmaceuticals. To facilitate the design of these extraction processes thermodynamic models can be applied to determine the concentrations of the phase formers.

In this thesis, ePC-SAFT was applied to model thermodynamic properties in aqueous two-phase systems, formed by combinations of polyethers, polysaccharides and salts. For the modeling of polyethers a copolymer approach was used accounting for three different segment types. This approach firstly enables the modeling of systems containing polyethers with a small number of modeling parameters and secondly allows for predictive modeling of various polymer compositions formed by these segments. By application of all pure-component and binary interaction parameters, aqueous two-phase systems generated by up to three phase formers were modeled. The so-obtained two phase-compositions and solution densities are in good agreement to experimental data. Within this work 33 different phase formers were used in 71 combinations leading to an ATPS, 29 of them were predicted. The modeling results were used to identify and evaluate the influencing variables, as temperature or type and composition of phase formers on the composition of aqueous two-phase systems.

Moreover ePC-SAFT was applied to determine the partitioning of amino acids, as building blocks of proteins, in different aqueous two-phase systems. The obtained results are in quantitatively good agreement to experimental data. By combination of the modeling parameters of amino acids the partitioning of dipeptides and tripeptides was predicted qualitatively correctly. The results obtained in this work contribute to facilitate the application of aqueous two-phase systems in the purification of biopharmaceuticals.