Packed-POCS with skin: A novel concept for the intensification of non-adiabatic catalytic processes demonstrated in the case of the Fischer-Tropsch synthesis

Abstract

Reaction heat removal/supply is a key issue in the development of intensified compact reactors for non-adiabatic catalytic processes. In this work, using the exothermal Fischer-Tropsch synthesis as a critical case, we show the possibility to boost the heat transfer performances of a packed-POCS (Periodic Open Cellular Structure) reactor by adding an outer metallic thermally connected skin to the conductive cellular internals. To this aim, the performances of a highly active Co/Pt/Al2O3 catalyst, packed in the form of 300 μm particles into the metallic structure 3D-printed in AlSi7Mg0.6, are assessed at industrially relevant operating conditions and compared with those of the same catalyst particles packed into the same POCS printed without the skin. Outstanding performances (CO conversion in excess of 80 %) are reached with flat axial and radial temperature profiles along the catalytic bed, in line with the excellent temperature control enabled by the conductive POCS. The presence of the skin strongly decreases the overall external temperature difference thanks to the enhanced thermal contact between the reactor wall and the ordered cellular structure, which governs the wall heat transfer. Accordingly, thanks to the presence of the skin, the temperature profile inside the reactor can be controlled much more effectively, thus enabling new operating windows that are not commonly accessible.