Development of a systematic evaluation of process alternatives for separation of bio-based diamines

  • Entwicklung einer systematischen Methodik zur Bewertung von Prozessalternativen für die Abtrennung von biobasierten Diaminen

Bednarz, Andreas; Pfennig, Andreas (Thesis advisor); Jupke, Andreas (Thesis advisor); Spiess, Antje C. (Thesis advisor)

1. - Aachen : Apprimus Verlag (2019)
Book, Dissertation / PhD Thesis

In: Ergebnisse aus der Verfahrenstechnik
Page(s)/Article-Nr.: 182

Dissertation, RWTH Aachen University, 2018


Biotechnological processes have become more and more popular for a wide range of productsin recent years, but are frequently constrained by substrate and product inhibition. This process limitation can be alleviated by process intensification, in particular by in-situ separation of the inhibiting products via extraction. This study applies reactive extraction of the polyamide monomer hexane-1,6-diamine from a cell-containing aqueous biotechnological production medium. For this purpose, a cascaded option tree method was developed and applied to determine the most promising solvents and reactive extractants for the separation of the selected diamine. After a preliminary identification of suitable solvent classes, equilibrium experiments were conducted to determine partition coefficients and separation efficiencies. In these experiments D2EHPA and isostearic acid were identified as promising reactive extractants and kerosene as well as oleylalcohol were identified as suitable solvents. As a next step, the coalescence behavior was investigated in a standardized settling cell. D2EHPA diluted in oleyl alcohol was selected as promising option for realization in an extraction column. First, the simulation of the extraction column, based on single-drop experiments measurements, was successfully validated in pilot-scale experiments. Second, the extraction column was used as bioreactor with integrated aeration and product extraction, applying a four-phase system, investigating the effect on drop distributions and holdup of the dispersed phases. Interestingly, aeration increased the holdup and decreased the drop size of the organic extractive phase, thereby potentially improving the separation efficiency of reactive extraction. Therefore, the feasibility of the in-situ reactive extraction of hexane-1,6-diamine from a cell containing biotechnological production media in an extraction column operating with four phases was proven.