Characterisation of thermally induced fouling processes using microstructured devices

• Applicants: Dr.-Ing. Katharina Jasch; Dr.-Ing. Alexander Stroh
• Subject Area: Chemical and Thermal Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 539483785

The formation of undesirable deposits during the processing of sensitive material systems, so-called fouling, is still an economically significant and not fully understood problem in many chemical processing industries. Basically, fouling processes are determined by an interaction and a constant overlapping of deposition and removal processes. During the fouling initialisation phase, the influence of which can significantly reduce fouling, deposition processes predominate, while removal processes still are negligible. A decoupling of these two individual mechanisms is therefore necessary for a targeted observation of the deposition and layer growth during initial fouling. For this purpose, microstructured devices prove to be particularly advantageous, as they allow precise process control as well as targeted influencing of the temperature profiles. With knowledge of the temperature profiles and the optical observation of the beginning of deposition, the fouling process can be linked to locally measured and simulated variables. The aim of the project is therefore the experimental and model-based analysis of the initial deposition site as well as the initial fouling mechanisms agglomeration/transport/deposition in thermally induced fouling using the example of a protein-containing model material system using microstructured devices. The project is divided into two phases. The subject of the 1st phase applied for here is experimental and simulative method development including model validation based on comprehensive parameter studies to clarify individual mechanisms. In the process, the necessary experimental, instrumental and simulative prerequisites for the holistic modelling will be created, which should be used in the intended 2nd project period. Finally, the aim of the 2nd project period is the development and verification of a holistic model for the prediction of local fouling phenomena under consideration of different influencing parameters. Furthermore, both kinetics and scaling effects will be taken into account. Within the 1st project period, single and multi-channel microsystems with local temperature measurement technology as well as with synthetically generated fouling layers will be developed and comprehensively thermodynamically and fluid dynamically characterised. Based on the experimentally collected data, a numerical flow simulation will be established, with which the temperature-driven growth of a fouling layer as well as the particle deposition during the protein-based reaction fouling can be simulated. The use of microstructured devices in combination with CFD simulations makes it possible to quantify local variables as a function of various parameters during the initial fouling as well as to develop resulting mechanistic submodels for a further holistic fouling modelling.

• DFG Programme: Research Grants