Design of structured packings using CFD-based optimization, absorption experiments and magnetic resonance imaging

• Applicants: Professor Dr. Alexander Penn; Professor Dr.-Ing. Mirko Skiborowski
• Subject Area: Chemical and Thermal Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544956881

In order to achieve the ambitious target of carbon neutrality by 2050, the chemical industry has to pursue major transformations. In addition to a gradual shift to renewable resources and energy systems, especially energy-intensive operations have to be optimized. In this context, thermal separation processes such as absorption and distillation are of crucial importance, as they not only contribute significantly to the energy demand of the chemical industry but are also of particular importance for CO2 utilization in the context of CO2 capture. Besides process intensification and energy integration measures on the process systems level, performance improvements of the individual unit operations are of utmost importance. Structured packings have become the most important internals for mass transfer and hydraulic performance improvements in absorption and distillation columns. While the design of structured packings has been actively researched for nearly six decades, additive manufacturing allows for novel, unconventional, and topologically complex packing structures and provides an efficient method for rapid prototyping. However, so far it has not had a considerable impact on the design of structured packings, since the resulting increased freedom in the design also poses a considerable challenge. This challenge may effectively be addressed by mathematical optimization methods, given that adequate problem formulations and performance models are available to efficiently compute the performance of the printed packing in a real application. In order to achieve this goal, the current project pursues the development of a systematic design approach based on mathematical optimization, that exploits the bi-functional use of computer-aided design (CAD) models for computational fluid dynamics (CFD) simulations and additive manufacturing. The latter allows for rapid prototyping of polymeric packings which will not only be investigated in hydraulic and absorption experiments, providing integral performance data but also enabling more fundamental insight into the fluid flow by means of an innovative and worldwide unique large-bore vertical Magnetic Resonance Imaging (MRI) system. The experiments will reveal the local distribution of the fluid and gas in the 3D-printed structured packings together with the local fluid velocities in all three spatial directions. The data obtained from the MRI experiments will enable a targeted improvement of the simulation models, which are providing the basis for a CFD-based optimization of individual packing designs, exploring different model formulations. Shape, topology, and parametric optimization approaches will be investigated to effectively develop innovative packing structures with significant performance improvements based on the optimization of the CAD models and validate the performance of the resulting packings experimentally using 3D printing.

• DFG Programme: Research Grants