Hydrodynamic behavior of a novel 3D-printed nature-inspired microreactor with a high length-to-surface ratio

Abstract

Microreaction technology has experienced almost exponential growth in the last decades due to significant practical benefits when compared with conventional reactors. However, the predominantly laminar flow impedes the required mixing in some processes. A novel design inspired by differential growth organic shapes in nature for improving mass transfer in microreactors is proposed. Firstly, this geometry allowed an area utilization of 16,1% and 27,2% higher than conventional serpentine and spiral channels, with the same hydraulic diameter, which can be useful for surface contact processes as in electrochemical reactions. Secondly, the performance of the microreactor was analyzed in terms of fluid flow and residence time distribution (RTD) for Reynolds in a range from 1-100. The continuous bending in the differential growth shape geometry leads to the formation of secondary vortices while approaching to the plug flow regime for the studied flow rates. These results were obtained by numerical analysis executed with the software COMSOL Multiphysics by solving three-dimensional Navier-Stokes equations with a convection-diffusion model for the species concentration. The validation of the RTD numerical model was conducted in a one-body 3D-printed microreactor by injecting a pulse of rhodamine B in water and measuring the response with colorimetric techniques. These organic shapes open a window to further research in microfluidics, as its parametric design can be adapted to a wide variety of reaction conditions.