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Understanding open-cell foams as catalyst supports: Design trade-offs and CFD/NMR comparisonWednesday (07.10.2020) 16:00 - 16:20 Room 3 Part of:
In the course of the last decade open-cell foams (OCFs) attracted considerable research interest as catalyst supports. Their rising relevance in engineering is due to their broad benefits: They provide a high surface area while keeping the pressure drop low. Furthermore OCFs show excellent heat transfer properties as well as good radial mixing, which is crucial to prevent hot spot generation during exothermic reactions. This is the basis for a safe and economic operation of catalytic reactors.
In order to improve their properties a good understanding of design parameters’ influence on heat and mass transfer as well as pressure loss are required. In this talk we use pseudo-homogeneous modelling, computational fluid dynamics (CFD) simulations and nuclear magnetic resonance methods to scrutinize reactive gas flows in OCFs. We present pareto-optimisation for open porosity and window diameter to face the trade-off problem between high catalyst inventory, low pressure drop and high thermal conductivity. The results show that, at production scale, the commonly reported low pressure drops are only achievable at the price of reduced space-time yield.
A key challenge to resolve the highlighted trade-offs lies in the understanding of the complex flow patterns, which determine pressure drop as well as mass and heat transfer. Therefore, we compare velocity profiles of CFD simulations within an OCF with nuclear magnetic resonance results. This allows a detailed observation of flow characteristics in the structure. Validated CFD simulations are a fast and cheap tool for deducing design rules for OCFs and thus making them more competitive as catalytic supports.