Populationsbilanz-basierte und morphologische Modellierung von Kristallisationsprozessen

  • Population balance based and morphological modeling of crystallization processes

Maßmann, Tim; Jupke, Andreas (Thesis advisor); Wiechert, Wolfgang (Thesis advisor)

Aachen : RWTH Aachen University (2020, 2021)
Dissertation / PhD Thesis

Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2020

Abstract

The integration of simulation tools in the development of crystallization processes represents a great potential for reducing costs and time. Currently the use of detailed simulation tools is low, reasons are low transferability and predictiveness of commercially available tools. The goal of this work is to improve transferability and predictivity by extension of the sequential determination of parameters and the integration of crystal morphology. Based on the two example systems itaconic acid and oxalic acid the added value by integration of crystal morphology to the transferability is shown. In the first part, the simulations parameters of the chosen time-driven n-Monte Carlo approach are determined for the selected kinetic models from literature. An extension of the approach is introduced which improves the simulation parameters, the number of representative crystals and the time step size. Thereby the overall simulation time is reduced. On the basis of the specified simulation parameters, the kinetic model parameters of breakage, growth, agglomeration and nucleation are determined for itaconic acid and oxalic acid. For the determination of the kinetic parameters, experiments were carried out according to the extended sequential scheme. It shows that the crystallization of itaconic acid using the one-dimensional model of the crystalphase is well described. However, the one-dimensional simulation of oxalic acid discloses strong differences between experiment and simulation. The reason for this is the significantly more pronounced deviation of the stationary crystal shape from the one-dimensional shape. This motivates the integration of the morphology to gain higher transferability and applicability. For the integration of the morphology the implementation and the necessary accuracy in the calculation of crystal morphology is studied. The impact of the morphology on the implemented kinetic rates is shown and the integration of the morphology is realized. The morphological model is then used to simulate itaconic acid and oxalic acid. For oxalic acid the kinetic breakage parameter is adjusted. Finally, the improved results by morphological simulation of oxalic acid is shown in comparison to one-dimensional simulation and experimental data.

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