In this work, we investigate the gas–solid heat and mass transfer in catalytically activated periodic open cellular structures, which are considered a promising solution for intensification of catalytic processes limited by external transport, aiming at the derivation of suitable correlations. Computational fluid dynamics is employed to investigate the Tetrakaidekahedral and Diamond lattice structures. The influence of the morphological features and flow conditions on the external transport properties is assessed. The strut diameter is an adequate characteristic length for the formulation of heat and mass transfer correlations; accordingly, a power-law dependence of the Sherwood number to the Reynolds number between 0.33 and 0.67 was found according to the flow regimes in the range 1–128 of the Reynolds number. An additional −1.5-order dependence on the porosity is found. The formulated correlations are in good agreement with the simulation results and allow for the accurate evaluation of the external transfer coefficients for POCS.

This review presents the numerical algorithms and speed-up strategies developed to couple continuum macroscopic simulations and detailed microkinetic models in the context of multiscale approaches to chemical reactions engineering. CFD simulations and hierarchical approaches are discussed both for fixed and fluidized systems. The foundations of the methodologies are reviewed together with specific examples to show the applicability of the methods. These concepts play a pivotal role to enable the first-principles multiscale approach to systems of technological relevance.

Periodic Open Cellular Structures are envisioned as potential enhanced catalyst substrates for heat and mass transferlimited processes. To enable their rational design, in this study, we propose a combined numerical and experimental approach to assess the pressure drop in the tetrakaidekahedral and diamond lattices since generalized correlations are not present in the literature. Deviations are observed between the model predictions available in the literature, which are possibly due to the different methods of investigation, that is, numerical on ideal geometries and experimental on reproductions. To reconcile the two approaches and prevent discrepancies, careful attention is paid here to the quality of 3D-printed replicas for experimental investigation to obtain results representative of ideal lattices. Computational Fluid Dynamics simulations and experiments are then employed together to cross-validate the results and then to perform a parametric analysis of the effect of the morphological properties on the pressure drop. The effect of the cell size and the porosity are discussed, enabling the derivation of engineering correlations for the prediction of the pressure drop across the lattices within the range of 1 < Re ds < 300. Finally, the performances of lattice materials are compared with those of conventional structured supports by evaluating the trade-off between the fluid−solid mass transfer rate and the pressure drop, which is crucial for several catalytic processes. Results show that the diamond lattice outperforms other cellular materials and can outperform ceramic honeycomb monoliths at low Reynolds numbers.

No abstract