Efficient removal of benzene in air at atmospheric pressure using a side-on type 172 nm Xe 2 excimer lamp

The photochemical removal of benzene was studied in air at atmospheric pressure using a side-on type 172 nm Xe 2 excimer lamp with a wide irradiation area. After 1.5 min photoirradiation, C 6 H 6 (1000 ppm) in air was completely converted to HCOOH, CO, and CO 2 at a total flow rate of 1000 mL/min. The initial decomposition rate of C 6 H 6 was determined to be 1.18 min −1 . By using a flow system, C 6 H 6 (200 ppm) was completely removed at a total flow rate of 250 mL/min. The conversion of C 6 H 6 and the energy efficiency in the removal of C 6 H 6 changed in the 31−100% and 0.48−1.2 g/kWh range, respectively, depending on the flow rate, the O 2 concentration, and the chamber volume. On the basis of kinetic model simulation, dominant reaction pathways were discussed. Results show that the O( 3 P) + C 6 H 6 reaction plays a significant role in the initial stage of the C 6 H 6 decomposition. Important experimental parameters required for further improvement of the C 6 H 6 removal apparatus using a 172 excimer lamp were discussed based on model calculations.