Decomposition of high-density toluene in water-vapor-mixed Nitrogen/Air using dielectric barrier discharge*

Volatile organic compounds (VOCs), one of the major air pollutants, are emitted from various industrial fields. Typical measures for processing VOCs are the combustion and the adsorption method. However, both have limitations including large energy consumption or high running costs. Alternatively, decomposition by a non-thermal plasma is regarded as an effective solution for pollutants treatment, due to the abundance of energetic electrons and reactive species. Therein, dielectric barrier discharge (DBD) is suitable for decomposing pollutants in the air, due to it can generate large-flow plasma.

Since oxygen-induced active species are considered to play a major role in the decomposition process in the air, in this study, decomposition experiments using air and pure nitrogen DBD plasma, were conducted. For the experiment, a DBD device was developed with a processing area of 200 mm long, 100 mm wide and 2 mm high. As a target gas, toluene was mixed in the air, nitrogen, and water-vapor-wetted nitrogen and air, at 100 ppm and 30 L/min. As a result, air plasma regardless of whether wet or not showed a higher decomposition rate than nitrogen. This indicates that active species derived from oxygen in the air contribute significantly to the decomposition of toluene.