A novel Static Mixer for photochemical reactions

Abstract

Photochemical reactions have become a widely studied topic in the past decade, as they are employed in a wide range of processes and are recognized to be a fundamental tool in the field of sustainable chemistry. Moreover, in recent years there is an increasing interest in turning discontinuous photochemical processes into continuous ones, since continuous processes can ensure better results in terms of productivity and selectivity. In this work, a novel static mixer useful to reach a plug-flow behaviour inside a square-based reactor, while not obstructing the photon flux coming from the light sources, was designed. Through RANS based CFD simulations, the residence time distribution of molecules inside the reactor was evaluated. Moreover, the effect of both absorption and scattering phenomena, which play a major role in photochemical reactions, was assessed. Finally, a case study was considered and the photochemical degradation of 2-hydroxybenzoic acid (2-HBA) was simulated. The conversion obtained in the reactor equipped with SMs was compared to an empty reactor, finding that the degradation efficiency is doubled.