Towards the Configuration of a Photoelectrocatalytic Reactor: Part 2-Selecting Photoreactor Flow Configuration and Operating Variables by a Numerical Approach

This work aims to select a photoreactor flow configuration and operational conditions that maximize the Photocatalytic Space-time Yield in a photoelectrocatalytic reactor to degrade Reactive Red 239 textile dye. A numerical study by Computational Fluid Dynamics (CFD) was carried out to model the phenomena of momentum and species transport and surface reaction kinetics. The photoreactor flow configuration was selected between axial (AF) and tangential (TF) inlet and outlet flow, and it was found that the TF configuration generated a higher Space-time Yield (STY) than the AF geometry in both laminar and turbulent regimes due to the formation of a helical movement of the fluid, which generates velocity in the circumferential and axial directions. In contrast, the AF geometry generates a purely axial flow. In addition, to maximize the Photocatalytic Space-time Yield (PSTY), it is necessary to use solar radiation as an external radiation source when the flow is turbulent. In conclusion, the PSTY can be maximized up to a value of 45 g/day-kW at an inlet velocity of 0.2 m/s (inlet Reynolds of 2830), solar radiation for external illumination, and internal illumination by UV-LEDs of 14 W/m(2), using a photoreactor based on tangent inlet and outlet flow.

Automated summary

This study aims to maximize the Photocatalytic Space-time Yield (PSTY) in a photoelectrocatalytic reactor by selecting a suitable photoreactor flow configuration and operational conditions. Numerical simulation using Computational Fluid Dynamics (CFD) was conducted to model the transport phenomena and reaction kinetics. The results show that the tangential flow configuration generates a higher PSTY compared to the axial flow configuration in both laminar and turbulent regimes. In addition, the use of solar radiation as an external illumination source is necessary to maximize the PSTY.