Experimental research on removal of toluene with non-equilibrium plasma technology

An experimental study on VOCs removal with non-equilibrium plasma generated by the combination of corona discharge and dielectric barrier discharge was carried out. Toluene was chosen as the target contamination in the experiment. In order to optimize the geometry of the non-thermal plasma reactor, the removal efficiency of toluene was compared for various inner electrode diameters (1.20 mm, 1.65 mm, 2.0 m respectively), different reactor materials (ceramic and PMMA), the presence and absence of ceramic raschig-ring packing. In addition, electricity parameters during the discharge process were measured under the experimental condition. Experimental results showed that toluene removal ratio increased significantly with increasing the voltage. With respect to toluene conversion, the smaller size electrode was slightly superior to the bigger size electrode when the voltage was low. However, the reverse was the case with further increase in voltage. Under the same experimental conditions, the removal efficiency of toluene with ceramic reactor was higher than that with PMMA reactor. Obviously, the removal of toluene was enhanced by filling some dielectric in the reactor. In the presence of ceramic raschig-ring packing, the convection was remarkably improved against in absence of padding. The discharge power during plasma processing to decompose toluene was measured using the U-Q Lissajous diagram. It was proved that the degradation of toluene with non-equilibrium plasma consumed less energy compared with other methods, and increasing discharge power was beneficial to toluene removal.