Innovative design of a continuous flow photoelectrochemical reactor: Hydraulic design, CFD simulation and prototyping

Photochemical (PC) and photoelectrochemical (PEC) techniques have being proven fruitful for environmental remediation, including the removal of organic emerging contaminants from water and wastewater, besides to be able to work as disinfection process. However, the majority of PEC reactors still remain in lab-scale and advances in the reactors’ design and optimization is required to achieve exploitation and practical application. In order to contribute to this area of research, this study aimed to develop an innovative design of a PC/PEC system. A designed 3-D honeycomb-type photoanode resulted in reactive area 4.8 times higher when compared to cylindrical reactors. Computational fluid dynamic (CFD) simulations were performed using CFX software. Reynolds number has shown turbulent regime well defined from a flow rate of 1000 L.h−1. A polyamide prototype was manufactured by a 3D-printer and hydraulic bench-tests were performed. The model adopted for the CFD simulations was validated by comparing calculations, bench-tests and simulation results. During validation process, differences varied between 1.84% and 5.06% for the total pressure and Reynolds, respectively, in the upstream flow chamber working at 1000 L.h−1. The design presented can provide scale-up due to it high modularity and be built in metallic electrodes mostly that layered by photo-responsive oxides, besides allowing the use of non-immobilized photocatalysts or just like for electrolytic treatment. Additionally, allow use of different UV sources (i.e. UV-LED, Xenon, Mercury lamps), improved mixing and adequate flow distribution.