Efficient removal of benzene in air at atmospheric pressure using a side-on type 172 nm Xe2 excimer lamp

The photochemical removal of benzene was studied in air at atmospheric pressure using a side-on type 172 urn Xe-2 excimer lamp with a wide irradiation area. After 1.5 min photoirradiation, C6H6 (1000 ppm) in air was completely converted to HCOOH, CO, and CO2 at a total flow rate of 1000 mlJmin. The initial decomposition rate of C6H6 was determined to be 1.18 min(-1). By using a flow system, C6H6 (200 ppm) was completely removed at a total flow rate of 250 mlJmin. The conversion of C6H6 and the energy efficiency in the removal of C6H6 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(P-3) + C6H6 reaction plays a significant role in the initial stage of the C6H6 decomposition. Important experimental parameters required for further improvement of the C6H6 removal apparatus using a 172 excimer lamp were discussed based on model calculations.