Non-thermal plasma by positive corona glow discharge using nano-structured Cu/CuO coated electrodes for benzene removal from air flow; removal enhancement and energy efficiency improvement

Abstract

• Benzene removal was about 67% with retention time of 5 s by Cu coating. • Cu coating showed uniform glow discharge along the discharge electrode. • The energy efficiency is increased by Cu-coating. • Glow column discharge was seen in CuO nanoparticle coating. • Benzene mineralization reached over 96% by Cu-coating. Benzene removal was investigated in the positive discharge non-thermal plasma. The wire-tube configuration was used for comparison of the discharge specifications and removal of benzene in three treatment conditions including not-coated stainless steel electrodes (D = 1 mm), Nano-hill Cu-coated stainless steel electrodes, and CuO nanoparticles coated stainless steel electrodes. A thermo-chemical electroless plating process was used for preparation of the electrodes. Comprehensive structural differences were seen between the electrodes and consequently different electrical discharge and pollution removal were observed. The results showed that the Cu was made much uniform coating and caused an obvious uniform discharge along the discharge electrode and the most removal efficiency of benzene was resulted with Cu-coated one up to 66.8 ± 2.8%, wherein the SCO 2 and the energy efficiency ( EE ) were 96.9 ± 0.1% and 1.85 ± 0.06 g/kWh, respectively. Given the results, 27.6% of energy efficiency improvement was obtained by Cu-coated reactor comparing the stainless steel. Also, it showed higher ozone destruction rate as the reaction constant [ k (L/J)] was obtained 2.9 × 10 −3 , 1.2 × 10 −3 and 1.6 × 10 −3 , respectively for Cu, CuO, and not-coated reactor.