Maroua ROUABAH is pleased to invite you to her thesis defense entitled “Experimental study and modeling of the wet pelletizing process” which will take place on Monday, April 4 at 2:00 pm in the conference room of the University Library of DOUA.
This defense will be held before the jury composed of :
SALEH, Khashayar, University Professor / TIMR – UTC, Rapporteur
SIEPMANN, Juergen, University Professor / U1008 – UDL, Rapporteur
JALLUT, Christian Professeur des Universités / LAGEPP – UCBL1, Examiner
OULLION, Mathieu, Doctor of Engineering / SOLVAY, Examiner
COGNÉ, Claudia, Senior Lecturer / LAGEPP – UCBL1, Thesis Director
BOURGEOIS, Sandrine, Senior Lecturer / LAGEPP – UCBL1, Thesis co-director
BRIANÇON, Stéphanie, University Professor / LAGEPP – UCBL1,
Translated with www.DeepL.com/Translator (free version)
Title: Experimental study and modelling of the wet granulation process
Wet granulation, which is a process commonly used in different industrial sectors (pharmaceutical, chemical, cosmetic, …), has been discussed in this thesis. This process consists of producing solid aggregates (granules) and represents an intermediate step in the manufacturing of different pharmaceutical forms (tablets, capsules…). The pharmaceutical industry requires highly controlled properties and a good reproducibility of the intermediate (granules) and final (tablets) products, so it is necessary to understand and control the process. Experimental and numerical studies were carried out in this thesis to gain a better understanding of the high shear wet granulation process. The numerical model is based on the discrete element method (DEM) that takes into account the intrinsic properties of the powder, the geometry of the process, and the operating conditions. It has the advantage of taking into account the dynamics of the particles and integrating complex phenomena between the particles such as cohesion.
First, preliminary work was carried out to calibrate the input parameters of the model. This required the adjustment of the static friction coefficient and the surface energy based on experimental measurements of the angles of repose. This calibration was validated using experimental tests (volumetry, drum mixing) and for different types of powder.
Second, the model was deployed to simulate the behaviour of the particles during the granulation process. A stepwise approach was developed to test the robustness of the model and a post-processing tool was programmed to calculate the size of the granules formed. Two scales of granulators were modelled (0.5L and 4L) and compared with experimental results. Although it was not possible to model particle sizes as fine as those found in the experiments, we concluded that the model was able to follow the growth kinetics of the granules and that the observed trends were similar.
Finally, a parametric study was carried out. It allowed to highlight the influence of the agitation speeds, the presence of the chopper and the binder addition method, both numerically and experimentally. A scaling study was also developed, concluding that the developed tool can secure the scaling-up of high shear granulators.
Wet granulation, High shear granulator, Modelling and Simulation by DEM, Numerical granule formation, Process Scale-up, Pharmaceutical process.