(158d) Modeling of Nucleation and Transport of Particles in Pharmaceutical Multiphase Reactors

Nucleation and transport of particles in multiphase reactors are two important mechanisms that significantly influence the final product properties. Modeling these mechanisms is, however, extremely challenging and different approaches exist for the treatment of the particle phase(s). We detail on our recent advances in the modeling of reactive mixing for organic nanoparticle precipitation. The Large Eddy Simulation approach is used for this purpose facilitated with an appropriate presumed-PDF reactive mixing model [1]. A study of inert and reactive mixing (see Figure 1) in a micro reactor as well as an investigation of different nucleation kernels is provided. This is done for the first time for a precipitation process involving organic nanoparticles. Also, we directly simulated particle transport processes in pharmaceutical multiphase reactors. This has been done using the Euler-Lagrange approach based on our previous work [2]. Specifically, we used a hard-sphere collision model and an appropriate stochastic model to account for particle-particle collisions and unresolved velocity fluctuations, respectively. Having this detailed information at hand, coalescence processes were studied directly. Also, collision statistics (see Figure 2) between two heterogeneous particle populations are reported for the first time using such a sophisticated particle tracking approach. References [1] S. Radl, D. Suzzi, J.G. Khinast: Fast Reactions in Bubbly Flows: Film Model and Micro-Mixing Effects, submitted to Industrial & Engineering Chemistry Research, 2010. [2] S. Radl, R. Sungkorn, D. Suzzi, J. Derksen, J.G. Khinast: High Performance Simulation of Bubbly Flows: Pushing the Limit by Using Conventional CFD and LBGK, Multi-Scale Modelling Symposium, Melbourne (Australia), 2009.