Agradecimentos: The authors would like to thank the financial support provided by CNPq (National Council for Scientific and Technological Development, Process 404760/2016-3) and FAPESP (São Paulo Research Foundation, Process 2014/07757-2, Process 2016/20842-4). This study was financed in part by the Coordination for the Improvement of Higher Education Personnel – Brasil (CAPES) – Finance Code 001 Ver menos

Abstract: The present paper introduces a full methodology for design, optimization and rapid prototyping of a new micromixer inspired on plate column tray, capable of operating under a wide range of flow throughputs with high efficiency for fluid mixing. The described methodology approaches the design through CAD modeling, Design of Experiments (DoE) and statistical methods along with numerical results from CFD for geometry optimization and scale-up and additive manufacturing of the device. The effects of channel width and characteristic length scales of the static elements on the fluid mixing performance was evaluated by a (DoE). The DoE was performed by numerical runs and evaluated the oil-ethanol mixing at Re = 0.1. The statistical analysis was used to achieve an optimal and scaled-up device. The optimal configuration of the microdevice was then evaluated by numerical and experimental studies. Numerical simulations for the oil-ethanol and water–ethanol systems were performed for the Reynolds number range of 0.001 – 100. The microdevice provided high mixing indexes (M > 0.97) with relatively low pressure drops. Also, the optimal design was numerically evaluated as a reactor in continuous biodiesel synthesis. The superior oil conversion (87.59%) was obtained for the residence time of 60 s. Finally, the optimal configuration was scaled-up to a reactor volume of 2.36 mL and a prototype was manufactured by 3D printing and used in the experimental synthesis of (Z)-5-(4-hydroxybenzylidene)thiazolidine-2,4-dione (HBT). The reactant conversion obtained from the 3D printed device was equivalent to the performance of a commercial capillary microreactor, but with higher throughput Ver menos