Chapter 13
Morphological Modelling and Simulation
of Crystallization Processes
Simon Schiele, Tijana Kovaˇ cevi´ c, and Heiko Briesen
Abstract The shape of crystals is an important property that has a great impact on
their physical behavior. Examples are flowability, dissolution, and growth kinetics.
Still, crystals are often described by a single size parameter. One reason is, that
today shape information is still hard to measure. Additionally, only few modeling
techniques exist that are able to describe the shape of crystals. In this chapter, these
issues are addressed by accurately describing crystals with mathematical models,
making the full morphological structure of crystals and their agglomerates accessible by stereoscopic and three-dimensional (3D) imaging techniques and using these
methods to model crystallization while considering the complex shape of the crystals. In addition, artificial neural networks (ANN) are used to classify whether projections of crystals show single crystals or agglomerates. As a final step, a case study
of a model of a mixed suspension mixed product removal (MSMPR) crystallizer
and a hydrocyclone are integrated into the software platform Dyssol and used to
dynamically simulate a crystallization process with recycling stream.
1 Introduction
Crystallization is an important process step in many pharmaceutical, chemical and
food processes. It is used to purify and formulate solid products. After crystallization
the products are initially suspended in the crystallization mother liquor. Subsequent
process steps then deal with the separation of the valuable solids from the rest of
the suspension. Such processes are typically centrifugation, filtration, and/or drying. All of the mentioned downstream processes and crystallization itself are highly
dependent on the morphology of the particles. The morphology also affects physical
properties such as dissolution rates that are particularly interesting for pharmaceutical
substances.
S. Schiele · T. Kovaˇ cevi´ c · H. Briesen (B)
Chair for Process Systems Engineering, Technische Universität München, 85350 Freising,
Munich, Germany
e-mail: heiko.briesen@tum.de
© Springer Nature Switzerland AG 2020
S. Heinrich (ed.), Dynamic Flowsheet Simulation of Solids Processes,
https://doi.org/10.1007/978-3-030-45168-4_13
435
Morphological Modelling and Simulation
of Crystallization Processes
Simon Schiele, Tijana Kovaˇ cevi´ c, and Heiko Briesen
Abstract The shape of crystals is an important property that has a great impact on
their physical behavior. Examples are flowability, dissolution, and growth kinetics.
Still, crystals are often described by a single size parameter. One reason is, that
today shape information is still hard to measure. Additionally, only few modeling
techniques exist that are able to describe the shape of crystals. In this chapter, these
issues are addressed by accurately describing crystals with mathematical models,
making the full morphological structure of crystals and their agglomerates accessible by stereoscopic and three-dimensional (3D) imaging techniques and using these
methods to model crystallization while considering the complex shape of the crystals. In addition, artificial neural networks (ANN) are used to classify whether projections of crystals show single crystals or agglomerates. As a final step, a case study
of a model of a mixed suspension mixed product removal (MSMPR) crystallizer
and a hydrocyclone are integrated into the software platform Dyssol and used to
dynamically simulate a crystallization process with recycling stream.
1 Introduction
Crystallization is an important process step in many pharmaceutical, chemical and
food processes. It is used to purify and formulate solid products. After crystallization
the products are initially suspended in the crystallization mother liquor. Subsequent
process steps then deal with the separation of the valuable solids from the rest of
the suspension. Such processes are typically centrifugation, filtration, and/or drying. All of the mentioned downstream processes and crystallization itself are highly
dependent on the morphology of the particles. The morphology also affects physical
properties such as dissolution rates that are particularly interesting for pharmaceutical
substances.
S. Schiele · T. Kovaˇ cevi´ c · H. Briesen (B)
Chair for Process Systems Engineering, Technische Universität München, 85350 Freising,
Munich, Germany
e-mail: heiko.briesen@tum.de
© Springer Nature Switzerland AG 2020
S. Heinrich (ed.), Dynamic Flowsheet Simulation of Solids Processes,
https://doi.org/10.1007/978-3-030-45168-4_13
435