Removal of Toluene from Industrial Gas by Adsorption-Plasma Catalytic Process: Comparison of Closed Discharge and Ventilated Discharge

Degradation of adsorbed toluene over 13X zeolite, 5A molecular sieve and Al2O3 by non-thermal plasma was investigated. Different discharge modes, including closed and ventilated discharge were compared. The carbon balance and COx yield of 13X zeolite were increased by 17.6 and 19.4% by ventilated discharge, respectively, compared with closed discharge. But for 5A molecular sieve and Al2O3, the carbon balance and COx yield by closed discharge were greater than those by ventilated discharge. It meant that the closed discharge was more suitable for low-concentration of VOC and the residence time of reactants would be prolonged. Removal of high-concentration VOC by ventilated discharge was more appropriate because of more reactive oxygen species generated. Furthermore, the effect of discharge background gas was studied. Removal of adsorbed toluene over Co/13X by oxygen and air with different flow rate as background gas were compared. The removal efficiency was reduced as flow rate of background gas increased. The oxygen-discharge was more efficiency for toluene oxidation and inhibited the generation of nitrogen oxides.