Modelling of emulsions in stirred tank reactors

The modeling of emulsions in stirred tank reactors (STR) is presented in this work. Emul- sions are widely used in chemical processes. Understanding the drop size distribution (DSD) is important for emulsions as it affects the transport phenomena. The droplet breakup and the droplet coalescence processes are the main phenomena which change the DSD and in the current study we mainly focused on the effect of the fluid dynamics on them and subsequently on the DSD. We studied the broad range of literature regarding the different aspects of this topic which are shortly discussed in the chapters. The numerical study of single phase flow in STR gave us a general overview of fluid dynamics in this apparatus. We developed a correlation for the local Sauter mean diameter based on the local fluid dynamics parameters like local shear rate and the experiment was executed in a Taylor-Couette flow device as it has a well-defined flow pattern compared to STR. Later on we introduced a novel breakup model based on the developed correlation and it was coupled with an Eulerian-Eulerian-Lagrangian approach to compute the liquid-liquid DSD in STR. The coalescence model was included besides the breakup model separately, either implicitly or explicitly. We applied these models on several experimental cases from the literature and generally the simulated results are in a good agreement with the experimen- tal data. In addition, we numerically investigated the common scale-up rules in the STRs by using the developed models and the computed results are in accordance with the data from literature.