Scheibenbogen, KarlKarlScheibenbogenMaly, MarcMarcMalyBernemann, VincentVincentBernemannFitschen, JürgenJürgenFitschenLeupold, MarcoMarcoLeupoldSchlüter, MichaelMichaelSchlüter2025-03-262025-03-262025https://hdl.handle.net/11420/54948In recent years, the biopharmaceutical industry has had to become more flexible and increase upstream yields, driving the uptake of process intensification strategies such as perfusion. This requires production equipment to support high cell density cell cultures requesting an oxygen uptake rate of 20 mmol O2 L-1 h-1 and above. Testing equipment capabilities typically involves characterization approaches such as determining oxygen mass transfer, energy input, and mixing performance. A broad measurement database and an appropriate mass transfer model CFD can be applied to better predict culture impact. However, cell activity sometimes deviates from expectations, and empirical validation of the used model is often lacking. In this research, a transparent version of the Biostat STR® 200, made of acrylic glass, was erected at the Institute of Multiphase Flows at Hamburg University of Technology to gain deeper insights into the two-phase flow pattern. The gas distribution and mixing behavior were investigated using high-resolution pictures and videos. In these assessments, two different stirrer combinations have been investigated for varied aeration rates and stirrer frequencies. With regards to oxygen mass transfer rate, the acrylic reactor replica behaves similarly to the industrial single-use bioreactor system, with deviations lying within the predefined ranges determined by the Sartorius Biostat STR product characterization approach. The volumetric mass transfer coefficient kLa is also comparable for both reactors. Consequently, it can be assumed that the visual recordings from the transparent model reflect dynamics from industrialized single-use cultivation chambers. Furthermore, high-resolution imaging of the acrylic replica of the Biostat STR® 200 enabled the systematic characterization of the mixing and mass transfer performance, helping us to understand the influence of stirrer speeds and gassing rates in combination with different sparger and impeller types as well as their interaction.enhttps://creativecommons.org/licenses/by-nc-nd/4.0/Gas-Liquid FlowMass TransferMixingSingle-Use BioreactorBubble SizeMixing TimeTechnology::660: Chemistry; Chemical Engineering::660.6: BiotechnologyLearning Objecthttps://doi.org/10.15480/882.1495710.15480/882.1495710.1002/bit.2552910.1002/9783527683369.ch9http://www.dechema.de/dechema_media/Recommendations for process engineering characterization of single-use bioreactors and mixing systems by using experimental methods (2nd Edition)_2020-ISBN: 978-3-89746-227-4.pdfCourse Material