Photocatalytic decomposition of benzene in an air stream in a continuous TiO 2 -coated optical fiber photoreactor (OFP) was demonstrated to be effective at relatively short retention times. An increase in TiO 2 coating thickness, fiber length and retention time improved the decomposition of benzene; however, excessive TiO 2 coating thickness and optical fiber length may hamper the reaction. The UV light intensity distribution on and within the optical fiber was modeled using Snell's law and UV light energy balance. The modeled profile indicated that the UV light intensity decreased rapidly along the axial and radial directions of the optical fiber. A mathematical model combining the continuity equations and Langmuir-Hinshelwood surface kinetics was established to adequately describe the reaction behavior of benzene decomposition in the OFP with only single TiO 2 -coated fiber.

Photocatalytic decomposition of gaseous benzene at room temperature was studied with a differential-type optical fiber reactor using TiO 2 as the photocatalyst. The effects of humidity, UV light intensity and benzene concentration on the performance of the reactor for benzene decomposition were investigated. It was observed that both the apparent quantum yields of benzene decomposition and CO 2 production were superior to the traditional photoreactor, especially under limited UV light supply. In addition, deactivation of the TiO 2 catalyst heavily relied on the humidity contained in the airflow. Purging with ozone-containing air rapidly decomposed the organic residues adhering to the TiO 2 surface and regenerated the deactivated catalyst within 30 minutes.