Beschrijving
Porous media are widely used materials in process engineering, e.g. as filters or catalyst supports. Among their key characteristics, the high specific surface area is commonly exploited in order to significantly increase the contact area between fluid and solid. Especially in the field of heterogeneous catalysis, this high contact area is of critical importance to the final performance of a reactor. Additionally, the spatial distribution of the commonly used catalytically active precious metals within the support structure is a key factor for a successful economic operation of the target process. However, industrial production of such heterogeneous catalysts often involves impregnation, drying and subsequent calcination, where the deposition location is highly dependent on the hydrodynamics within the porous media.Especially drying has a major impact on the final distribution of the waterborne active species. There, capillary-force induced hydrodynamics introduce a significant redistribution of liquid within the pore system. Additionally, in the case of relatively high precipitate volumes, the introduced change in pore size geometry leads to an intricate interplay between capillary and viscous forces. Therefore, an in-depth understanding of the redistribution process, as well as its behavior within a continuously changing geometry due to industrially relevant deposit loads is required to provide optimized porous structures.
To better understand this phenomena we have developed a particle scale model based on Darcy-type of flow, taking into account the relevant heat and mass transfer mechanisms. Additionally, we introduced a capillary model that enables the computation of the hydrodynamic properties of the porous media from arbitrary pore size distributions. Within this presentation, we highlight a precipitation model coupled to the computation of the hydrodynamic properties and its impact on post-drying distribution of the precipitate.
| Periode | 7 jul. 2023 |
|---|---|
| Evenementstitel | Netherlands Process Technology Symposium 2023 |
| Evenementstype | Congres |
| Conferentienummer | 18 |
| Locatie | Enschede, NederlandToon op kaart |