Numerical simulations oflovastatin crystallization in aT-shaped 2D mixer

Abstract: The rise of battery driven technology and the strive towards circular economy calls for the indefinite recycling of metals used in batteries. To be able to study and optimize the processes used in recycling, mathematical models are required. One way of recycling metals is to leach them into an acid, this solution is then mixed with an anti-solvent to induce cryztallization of the metal. The resulting crystals can then be retrieved and further processed. This type of process is also used in the pharmaceutical industry to crystallize medicines. A mathematical model and a solver has been developed at KAIST (Korean Advanced Institute of Science and Technology) called multiphase particle-in-cell coupled with population balance equation (MP-PIC-PBE) that can model anti-solvent crystallization in pharmaceuticals. This paper provides a thorough description on the governing mathematical equations as well as the numerical framework used to solve them. A study of the discretization of the internal coordinates is performed to determine the appropriate discretization. Further the associated CFD-solver implemented in OpenFOAM is applied to simulate the mixing of a solution of lovastatin in methanol being mixed with pure water as an anti-solvent. The geometry is a 2 dimensional T-shaped mixer. For the simulation results presented here, the Reynolds number based on the injected solution is kept constant at 4000 while four different solution temperatures are considered. Finally, the paper concludes with a discussion of the model and solver, and some recommendations for future work are provided.