Analysis of the effective thermal conductivity of isotropic and anisotropic Periodic Open Cellular Structures for the intensification of catalytic processes

Conductive metallic Periodic Open Cellular Structures (POCS) are considered a promising solution for the intensification of heat-transfer limited catalytic processes thanks to their enhanced thermal conductivity. Herein, the heat conduction in the solid matrix has been investigated through 3D numerical simulations. The porosity together with the intrinsic conductivity of the material have a major effect on the effective thermal conductivity, while a negligible influence of the cell shape and size is found. A correlation previously derived for the description of open cell foams shows an excellent agreement with the results of POCS structures. POCS are produced by additive manufacturing, e.g. 3D printing, providing degrees of freedom in the geometry design. Anisotropic cubic cell structures have been investigated for the first time to explore the possibility to promote or decrease preferentially the heat conduction in the radial or the axial direction. At constant solid fraction and cell size, these structures can improve the effective thermal conductivity of the solid matrix up to 40 % and 100 % for structures thickened in two or one direction respectively. This concept paves the way to the design of metamaterials with tailored properties, granting additional degrees of freedom for the intensification of heat-transfer limited catalytic processes.