Joint Press Release by the University of Bremen and the Association of German Engineers (VDI)
Production Engineering student Alexander Zimmermann from the University of Bremen produced such an impressive master’s thesis on Fischer-Tropsch synthesis (FTS) that he has now been awarded the Bremen Engineering Prize 2022 by the Bremen chapter of the Association of German Engineers (VDI). “As part of his master’s thesis, the winner of this year’s engineering award made impressive efforts to improve this process,” was the rationale for choosing this year’s prizewinner of the prestigious award. “The current energy crisis and the lack of raw materials make the Fischer-Tropsch synthesis more interesting than ever.”
The Fischer-Tropsch synthesis was discovered in Germany and quickly developed to technical maturity from 1920 onward. In the 21st century, the process is experiencing a renaissance, as liquid fuels will also have to be produced from alternative raw materials such as natural gas, coal, or biomass.
Tube bundle reactors and bubble column reactors have so far prevailed for the technical execution of the highly exothermic reaction. Since both reactor technologies have drawbacks, new reactor concepts are being investigated. Fixed-bed reactors with a discharge of highly porous pellets have the potential to significantly intensify the process of the AGV, but a limitation of material transport usually prevents it from actually being exploited. During the reaction, the reaction products also accumulate in the pores, so that the material flow is greatly slowed down.
New Basis for the Process Provided
In his master’s thesis on “Material transport of product mixtures of FTS analysis using NMR,” Alexander Zimmermann provided important new foundations for this method.
The aim of this work was to understand the relationship between the pore structure and the material transport behavior of the reaction products and thus to enable the selection of the optimum structure of the pellets used for the most throughput reactor operation possible. Alexander Zimmermann examined special pellets that support fast material transport and an improved reaction process through hierarchically branched pore structures.
As part of his master’s thesis, he undertook numerous experiments using Nuclear Magnetic Resonance (NMR) – similar to medical imaging MRI – in order to evaluate the material transport in the pellets used for catalysis. The special feature was to characterize the behavior of a mixture of the reaction products in the pores of the pellets used. This showed that the special hierarchical pore structure has a particularly beneficial effect on the material transport of such mixtures.
Cost-Effectiveness Can Be Significantly Increased
From this new perspective, it was possible to identify new potential advantages of this pore structure for FTS material transport. This will significantly increase the cost-effectiveness of this process. The industrial application of these new findings can significantly improve the intensity and quantity of the chemical raw materials obtained in this way. “The work of Alexander Zimmermann makes it clear that we can still exploit considerable development potential by improving the climate,” concludes the VDI.
The work was supervised by Professor Jorg Thöming (Faculty of Production Engineering), who also suggested his student for the prize. “I was impressed by Alexander Zimmermann’s master’s thesis and how deeply he penetrated the demanding physical theory required in order to solve this very challenging task in a short space of time. His work was so advanced that he was able to develop an ingenious experimental plan for measurements using pulse gradients. These types of measurements were new to us in the field.”
Zimmermann’s clear and well-thought-out analysis of the measurement data shows the extent to which he understood the new theory for him. “He was then able to use his results in an exemplary manner to solve the process-related problem. It consisted of finding out how the pores in catalysts must be structured in order to also allow a two-phase material transport in the best possible way. His results bring the goal of more cost-effective synthetic fuels within reach,” says Jorg Thöming.
FOR EDITORIAL OFFICES: You are cordially invited to the award ceremony for the Bremen Engineering Prize 2022 on November 24 (6 p.m.) at Ecomat Bremen (Ecoteria Room, Cornelius-Edzard-Str. 15, 28199 Bremen). Alexander Zimmermann will be available for discussions both at this event and in the run-up to the award ceremony (by phone or online).
Spokesperson at the VDI – The Association of German Engineers
Tel.: +49 7000 100-1038
Cell: +49 172 424-7155