title: Computational and experimental investigation of needle-shaped crystal breakage.
abstract: Needle-shaped crystals are a common occurrence in many pharmaceutical and fine chemicals processes. Even if the particle size distribution (PSD) obtained in a crystallization step can be controlled by the crystal growth kinetics and hydrodynamic conditions, further fluid-solid separation steps such as filtration, filter washing, drying, and subsequent solids handling can often lead to uncontrolled changes in the PSD due to breakage. In this contribution we present a combined computational and experimental methodology for determining the breakage kernel and the daughter distribution functions of needle-shaped crystals, and for population balance modeling of their breakage. A discrete element model (DEM) of needle-shaped particle breakage was first used in order to find out the appropriate types of the breakage kernel and the daughter distribution functions. A population balance model of breakage was then formulated and used in conjunction with experimental data in order to determine the material-specific parameters appearing in the breakage functions. Quantitative agreement between simulation and experiment has been obtained.
authors.affiliation: Department of Chemical Engineering, Institute of Chemical Technology, Technická 5 166 28 Prague, Czech Republic.
authors.forename: Zdenĕk
authors.initials: Z
authors.lastname: Grof
authors.forename: Carl M
authors.initials: CM
authors.lastname: Schoellhammer
authors.forename: Pavol
authors.initials: P
authors.lastname: Rajniak
authors.forename: František
authors.initials: F
authors.lastname: Stĕpánek
mesh_terms: D003198:Computer Simulation; D003460:Crystallization; D005374:Filtration; D057446:Hydrodynamics; D008956:Models, Chemical; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000737:chemistry*
chemical_list: D004364:Pharmaceutical Preparations