The separation of liquid-liquid dispersions is essential in various industrial processes, including liquid-liquid extraction and reactions in the biotechnology, pharmaceutical, hydrometallurgical, chemical, and recycling industries. This separation can be achieved using a gravity settler designed by an experiment- and model-based approach. This approach examines phase separation behavior in a batch-settling cell and then parameterizes the corresponding models. Sedimentation, droplet deformation, and coalescence phenomena significantly influence phase separation behavior, all of which are affected by the polydispersity of the liquid-liquid system. This work focuses on the experimental and model-based analysis of dispersion and phase separation phenomena in batch-settling experiments, considering polydispersity. Moreover, this work aims to provide an accessible and reliable modeling approach for describing phase separation in a batch-settling cell, incorporating polydispersity in sedimentation, dense-packed zone formation, droplet deformation, and coalescence. The first part of this work focuses on the design of a batch-settling cell and the automation of the experimental procedure. Moreover, automated droplet size distribution and phase separation evaluation methods are developed. The automation aims to enhance reproducibility, objectivity, reliability, and safety while reducing time and labor effort. The verification by experimental data shows that the automated procedure and evaluation methods provide reliable data with high reproducibility, significantly reducing time and labor effort. The second part of this work systematically investigates the droplet size distribution during dispersion in the batch-settling cell, which is an essential initial step in phase separation. The investigation is performed within a range of operating conditions and material system properties relevant to technical applications. Moreover, a model for the droplet size distribution is developed based on the experimental results. The experimental results show dependencies of droplet size distribution on operating conditions and material system properties. The developed model shows validity across a wide range of operating conditions and material system properties. The third part of this work focuses on investigating phase separation behavior. First, batch-settling experiments are conducted to generate data for model verification. Next, adopted and developed models are introduced describing sedimentation, droplet deformation, and coalescence phenomena. Their performance is then assessed separately through a sensitivity analysis to evaluate their reliability. Finally, the overall developed modeling approach is validated using the batch-settling experiments conducted in this work. The sensitivity analysis demonstrates the simulation performance of the individual models, identifying suitable simulation parameters. The validation of the modeling approach shows high agreement with experimental data.
Stepan Sibirtsev (Wed,) studied this question.