Abstract

The improvement in the decomposition of volatile organic compounds (VOCs) was investigated by combining discharge plasma with photocatalyst (TiO₂). The reactor consists of a coaxial cylindrical electrode system and dielectric barrier discharge is used for the processing. In order to combine discharge plasma with photocatalyst, an electrode with photocatalyst was developed as an inner electrode instead of the conventional metal electrode. Time dependence of toluene decomposition was compared for the reactors with and without photocatalyst. As a result, in dilute toluene (20-25 ppm) at an energy consumption of 18 J/l, time averaged toluene decomposition rates by the conventional type reactor, the photocatalyst-plasma reactor with TiO₂ pellets, the photocatalyst-plasma reactor with TiO₂ coating electrode were 31% at 5.8 g/kWh energy efficiency, 45% at 6.9 g/kWh, and 59% at 8.9 g/kWh, respectively. It was found that the combination of the plasma and TiO₂ was effective for improving toluene decomposition at lower applied voltages and the lower energy consumption.