Enhancement of VOCs removal using a novel double‐tube packed bed catalytic dielectric barrier discharge (DPDBD) reactor

Abstract

AbstractWe developed a novel double‐tube packed bed catalytic dielectric barrier discharge (DPDBD) reactor to degrade toluene. The DPDBD reactor contains four discharge cells with one power supply, namely, A–D. NiO/γ‐Al2O3 is packed in cell A to effectively destroy the branched chains in toluene. TiO2/γ‐Al2O3 is packed in cell B owing to its high catalytic oxidation activity to weaken the benzene rings and mineralize the generated partial aromatic compounds. Cell C is a pure DBD process without any catalyst packed to thoroughly mineralize all the generated aromatic compounds and convert CO into CO2 and NO into NO2. γ‐Al2O3 is packed in cell D to reduce the concentrations of byproducts, including O3 and NO generated by air through oxidation. The combinations of the four discharge cells are optimized by the treatment of −3000 mg m−3 of toluene at 11 kV. In comparison with a double‐tube dielectric barrier discharge (DDBD) reactor without catalyst packing and with a total discharge length of 6 cm, the selectivity of CO2 was significantly improved from 45% to 57% when the discharge lengths of A, B, C, and D are 2, 4, 4, and 2 cm, respectively. Furthermore, the concentrations of O3 and NO in the outlet can also be effectively reduced from 2.80 and 210 mg m−3 to 1.30 and 60 mg m−3, respectively. We also investigated the effects of applied voltage and styrene initial concentration.