Influence of operating parameters on photocatalytic oxidation treatment efficiency: contact time investigation

The photocatalytic oxidation (PCO) of toluene was performed in a dynamic loop reactor with control of key process parameters: UV-light intensity and air flow rate. The initial concentration of toluene was fixed at 800 ppb. The relative humidity was set at 50% (i.e. 13 000 ppm) to be close to real indoor air conditions. Two photocatalytic media geometries were used in a way to optimize the contact time. Flat and pleated geometry were studied. CFD simulations were performed with ANSYS-CFX® computational fluid software. Influence of the contact time was assessed and related to the geometry of the material. The local contact time was evaluated to be 9 times higher regarding the pleated geometry. This latter impacts the global PCO efficiency; it plays a role in the contact time between the effluent and the photocatalytic material.