Plasma-catalytic ethylene removal by a ZSM-5 washcoat honeycomb monolith impregnated with palladium

The effective removal of dilute ethylene in a novel honeycomb plasma reactor was investigated using a honeycomb catalyst (Pd/ZSM-5/monolith) sandwiched between two-perforated electrodes operating at ambient temperature. Herein, the dependence of catalyst performance on the binder fraction, catalyst preparation method, and catalyst loading was examined. Ethylene removal was carried out by a process comprising cycles of 30-min adsorption conjugated with 15-min plasma-catalytic oxidation. Interestingly, the performance of the cyclic process was superior to continuous plasma-catalytic oxidation and thermally activated catalyst in terms of energy conservation, i.e., ~36 compared to ~105 and ~300 J/L, respectively. Hence, the novel cyclic process can be considered advanced-oxidation technology that features room-temperature oxidation, offers low energy consumption, negligible hazardous by-products emissions such as NO_x and O₃. Moreover, the process operated under described conditions: low-pressure drop, ambient atmosphere, a mechanically stable system, and a simple reactor configuration, suggesting the practical applicability of this plasma process.