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%0 Thesis %A Biselli, Andreas %T Modellbasierte Untersuchung der chromatographischen Abtrennung von Itaconsäure aus Fermentationslösungen unter Verwendung hydrophober Adsorbentien %V 12 %I Rheinisch-Westfälische Technische Hochschule Aachen %V Dissertation %C Aachen %M RWTH-2024-12240 %B Aachener Verfahrenstechnik - Fluidverfahrenstechnik - Dissertationen %P 1 Online-Ressource : Illustrationen %D 2024 %Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University 2025 %Z Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024 %X This thesis investigates the potential of highly hydrophobic polymeric adsorbents for separation problems in industrial biotechnology. As an exemplary separation problem, the separation of itaconic acid (IA) as a dicarboxylic acid from complex, aqueous fermentation solutions via a strongly hydrophobic, non-functionalized, polymeric adsorbent was considered. The aim of the work was to obtain a profound understanding of the process with respect to the phenomena dominating the separation process by a methodical approach consisting of experimental and simulative investigations. The adsorption capacity of dicarboxylic acids on hydrophobic adsorbents is determined by the acid species present. Therefore, the pH-dependent distributions of the three acid species of IA were first determined. Here, approaches based on the assumption of ideal solutions were contrasted with approaches based on activity models to account for non-ideal dissociation behavior. Based on the knowledge of pH-dependent species distribution, pH-dependent adsorption isotherms of IA in aqueous solution on the strongly hydrophobic polymeric adsorbent Chromalite™ PCG1200C were determined in the pH range from 2 to 8. It was shown that in particular the fully protonated species of IA exhibited an adsorption tendency to the hydrophobic adsorbent surface. In subsequent pH-dependent pulse experiments with pure IA, dynamic phenomena in the separation column were investigated with the aid of in-line Raman spectroscopy. In-line Raman spectroscopy enabled the temporal measurement of the concentrations of the IA species at the column outlet. It was shown that as a function of pH, a separation of the three IA species occurs in the chromatographic separation process. These eluted as three nearly separated peaks. The results show that the separation process is characterized by the superposition of local, species-dependent adsorption and desorption reactions and resulting dissociation reactions. A mechanistic simulation model was developed on the basis of the experimental investigations. In addition to the relevant mass transfer effects of convection and diffusion, the model represented the local dissociation reactions in the liquid phase previously identified as relevant, as well as individual adsorption reactions for the different IA species. The simulation model was successfully validated against experimental data. The elution times as well as the main characteristics of the elution profiles of the three IA species were successfully simulated by the model. In a final simulative analysis of the separation technique based on the exemplary in situ separation of IA from a fermentation process, the potential of the separation technique was demonstrated. %F PUB:(DE-HGF)11 ; PUB:(DE-HGF)3 %9 Dissertation / PhD ThesisBook %R 10.18154/RWTH-2024-12240 %U https://publications.rwth-aachen.de/record/999650