Master Thesis – Characterization and optimization of a 3D printed continuous crystallizer for pharmaceutical applications


Crystallization is one of the most important unit operations in the production of active pharmaceutical ingredients (APIs) in a solid form. It defines product properties like purity, crystalline structure, crystal size and the crystal size distribution, which is especially important for further downstream operations like filtration and formulation of pharmaceuticals. Because of lower production volumes in the pharmaceutical industry compared to industrial inorganic salt production, the development of continuous processes for the production of certain APIs was not profitable in the pharmaceutical industry in the last decades.

Nevertheless, companies are now investing into the development of continuous processes for synthesis and also crystallization, since a constant quality can be ensured and no service time in between production batches is necessary. Therefore, crystallizers and crystallization processes for continuous applications have to be developed.

The aim of this master thesis is to design and characterize a continuous crystallizer by exploiting recent advances that have been accomplished in the field of additive manufacturing (3D-printing). Based on the working principle of an OSLO-type crystallizer, this technique will facilitate realizing a modular setup. Thereby, rapid replacement of parts of the reactor is feasible, allowing to analyze their influence on the overall behavior. This strategy aims to provide previously unattainable insights into the behavior of continuous crystallizers. The main challenge of the thesis will be the characterization of the current crystallizer using simple model systems. In a possible second step, alternative designs should be evaluated and produced, using additive manufacturing, to optimize the overall performance of the crystallizer.

Figure 1: Current Design of the OSLO type crystallizer.


  • Literature study on crystallization / especially continuous crystallization
  • Simple crystallization experiments and evaluation of the results (Particle size distribution, concentration measurements [HPLC, optical methods], Residence time distribution measurements)
  • CAD drawing and 3D printing


  • Background in chemical engineering, chemistry or related studies
  • Interest in the above mentioned fields
  • Basic lab work experience
  • NO PRIOR KNOWLEDGE in CAD or 3D printing required
  • Good work ethic

What we offer:

  • Integration in a research project supported by an industrial partner
  • Support from the CoSy Pro Team
  • Paid Thesis
  • Experience in an upcoming field of greatest importance
  • Start: As soon as possible.


Dipl.-Ing. Nys Nico, BSc - Tel.: +4331687330438

Assoc. Prof. Dipl.-Ing. Dr.techn. Heidrun Gruber-Wölfler

Paid Master’s Thesis – Molecular Dynamics Simulations of Transport in Polymers

Polymers are used in the electrical industry to insulate devices. Especially in corrosive atmospheres the investigation of the degradation of these polymers and the protected devices is of vital importance to increase their longevity. One main influence is the diffusion of corrosive substances through the protective layer of a device. In recent years as computational power became cheaper, using molecular dynamics simulations to quantify transport properties of polymers became more commonly used.

In this thesis molecular dynamics (MD) simulations should be used to quantify the transport processes of different penetrator molecules in polymers. Investigations regarding the polymer’s chain-length, the degree of cross-linking, as well as the charge of the penetrator molecules under different environmental conditions should be conducted.


  • Running and analyzing molecular dynamics simulations of polymers
  • Investigation of physical properties of polymers


  • Solid background in chemical engineering
  • Knowledge of Matlab or Python
  • Enthusiasm to work with theories, software, and computer algorithms
  • Interest and enthusiasm for performing simulation on supercomputers

Work on the thesis is paid (6 months), and we offer office space, computers, simulation software and expertise, as well as integration to a highly-relevant research project

Dr. Stefan Radl (; 0680 12 22 168)
Dipl.-Ing. Philipp Mayr, BSc. (

Paid Master Thesis or Student Job - Developing a Novel Drug Delivery System for Special Patients


The Institute of Process and Particle Engineering is a world leader in the development of pharmaceutical products and processes.

In this context, we are offering a paid master thesis where the student is employed at an external company.

The goal of the master thesis is to create the basis for product development, focusing on a novel drug delivery system where the medicine is contained in a flavored gel, either as solution, emulsion or suspension. Drug delivery occurs via breaking a seal of a snap-package and sucking out the flavored gel. Target patient populations includes:

  • Geriatric patients (frail & old patients)
  • Pediatric patients (kids)
  • Emergency applications


  • Literature study on competitor products and patent situation
  • List of the 20-30 most important medicines for the three target populations and corresponding biopharmaceutical classification
  • Research on formulation strategies (solutions, emulsions, suspension) with sufficient stability
  • Selection of 3 model APIs (different categories) and formulation of the gels
  • Stability testing under stress conditions


  • Background in pharmaceutical sciences, pharmaceutical engineering or medicines
  • Student in pharmacy, pharmaceutical engineering, chemical engineering or related

What we offer:

  • Integration in an internationally leading team
  • Opportunity to be part of a commercialization project
  • Paid thesis

Start: Spring 2021

Contact: Univ.-Prof. Dr. Johannes Khinast,

Paid Master Thesis or student job: Comparing Bioreactors with different scales and/or geometries


The Institute of Process and Particle Engineering is a world leader in the development of simulation tools for industrial-scale bioprocessing units, funded by the Spin-Off Fellowship Program of the FFG. For example, our current code can model processes in large-scale bioreactors, up to 200m3 .
We are therefore offering a student job with the possibility to do a master thesis with the goal of creating a comparison algorithm for bioreactors. The objective is to find the influencing factors that determine the productivity difference between reactors. This should be done by comparing reactors of different scales and for reactors at the same scale but different geometry and should aid scale up or process transfer processes in the industry.


  • Literature study on available influencing factors or comparison concepts for the production in bioreactors using cells or microorganisms
  • Propose an algorithm for the comparison of reactors
  • Do scale ups or process transfer virtually


  • Background in biotechnology, biochemistry, molecular microbiology or similar
  • Being familiar with industrial production in bioreactors

What we offer:

  • Integration in an internationally leading team
  • Opportunity to be part of a commercialization project
  • Paid thesis

Start: Fall 2020

Dr. Christian Witz
0316 873 30416

Continuous Cooling Crystallization


For this construction thesis we are looking for a student to design a water bath made of stainless steel for continuous cooling crystallization in a tubular reactor (plug flow crystallizer).

Using such a tubular crystallizer the continuous cooling crystallization process should be carried out in two water baths of different temperature. Each water bath has separate glass inserts which enable the visual observation of the crystallization process within the tubes via a high speed camera. To achieve high resolution images a backlight source e.g. a LED panel in addition to the camera is necessary. Due to the reflection of the water inside the bath the distance between the backlight and the camera should be as short as possible. To keep the tube cycles uniformly immersed and to guide them special tube mountings are also required.


  • To design a water bath of stainless steel with glass inserts for the image-based observation of a continuous cooling crystallization within a transparent tubular crystallizer.
  • To make a selection of necessary materials and equipment and process the orders
  • Image-based monitoring and observation of crystal segments via high speed camera and backlight
  • Doing some final experiments to demonstrate the applicability of the two water baths for visual investigations.


  • Background in chemical / pharmaceutical engineering or chemistry
  • Basic experience in working with CAD drawing desirable
  • Basic experience in lab work

What we offer

  • Integration in an internationally leading team


Dipl.-Ing. Alexander Meister, BSc
Inffeldgasse 13 / III, 8010 Graz

Michaela Cibulka

Institut für Prozess- und Partikeltechnik
Inffeldgasse 13
8010 Graz

+43 316 873 - 30403
+43 316 873 - 1030403
nach Vereinbarung