A comprehensive study on scaling up ethylene abatement via intermittent plasma-catalytic discharge process in a novel reactor configuration comprising multiple honeycomb monoliths

• Stable plasma generation in reactor configuration comprising multiple honeycomb monoliths. • Linear relationship between discharge power and increased number of monoliths. • High ethylene adsorption capacity in an open channeled monolith catalyst at humid conditions. • Higher ethylene removal efficiency with high energy yield at low energy requirement. • Simplified overall system and operation at atmospheric conditions. Dilute ethylene (C 2 H 4 ) was removed in a novel plasma reactor comprising multiple honeycomb monoliths consisting of up to four PdO/ZSM-5/monolith catalysts. These monoliths were packed in a tubular reactor separated by mesh electrodes alternatively grounded or connected to a high voltage (HV) power source. The effect of the number of monoliths on the discharge power, adsorption, and removal of C 2 H 4 was investigated. Additionally, the influence of the energy input, C 2 H 4 inlet concentration, and gas flow rate on the C 2 H 4 abatement was examined. The adsorption capacity, C 2 H 4 conversion, and energy efficiency were observed to increase as the number of monoliths increased. The effect of the palladium (Pd) loading technique, namely ion exchange (IE), incipient wetness impregnation (IM), and combined IE-IM, IE followed by IM, on the C 2 H 4 adsorption was also studied. The combined IE-IM method presented an exceptional adsorption capacity of ∼136 µmol/g catalyst under humid conditions despite nonpolar nature of C 2 H 4 . C 2 H 4 removal was performed via both continuous and cycled storage-discharge (CSD) plasma-catalytic oxidation processes. The CSD process was conducted in two ways: with intermittent C 2 H 4 feed (CSD-IEF) and with maintained C 2 H 4 feed (CSD-MEF), both comprising intermittent plasma discharge. Intriguingly, the performance of the CSD-MEF process was superior (56 J/L, 1.61 g/kWh) to that of the CSD-IEF (119 J/L, 0.98 g/kWh), and continuous process (∼228 J/L, 0.53 g/kWh) in terms of energy efficiency as well as the overall simplicity of the system.