Experimental demonstration of the heat transfer — pressure drop trade-off in 3D printed baffled logpile structures

Shaping of catalytic material by 3D printing allows for greater design freedom, which can be used to optimize reactor operating windows. A promising concept in this regard is the use of structures with porous baffles, which induce a cross-flow regime that offers enhanced heat transfer at relatively low pressure drop. In this work, eighteen novel cylindrical 3D printed baffled logpile structures were designed and their heat transfer — pressure drop trade-off was quantified experimentally. It was found that the performance of these full-scale structures could be estimated from previous pseudo-2D computational fluid dynamics simulations for variations in configuration and baffle gap spacing. Moreover, the structures with 50 µm baffle gap spacing demonstrated superior heat transfer performance over a packed bed of pellets, as hypothesized. The number of baffles per unit length was introduced as a novel design variable. Remarkably, a reduction of this parameter led to comparable heat transfer performance while achieving a significant decrease in pressure drop. Finally, positioning of consecutive baffles under an angle was demonstrated to have a favorable effect. The results were correlated to facilitate reactor design considerations. Overall, this work sheds light on the process intensification potential of 3D printed baffled logpile structures as novel structured catalysts, enabled by offering enhanced heat transfer characteristics at relatively low pressure drop, both of which can be tailored to meet specific process requirements.