Generation of Practical-Scale Honeycomb Plasma Discharge in Monolith Reactor System for Environmental Applications: Ethylene Removal Aimed Enhancement of Agricultural Storage Capability

Honeycomb plasma discharge has been successfully generated in a simple configurated sandwich-type plasma reactor with a commercial-scale monolith. The plasma generation between two perforated electrodes with a large gap does not occur. However, uniform honeycomb discharge is ignited and sustained when the monolith is sandwiched between perforated electrodes. The air plasma in the honeycomb monolith hugely depended on the humidity of the feed gas, which is crucial for the discharge creation on the commercial scale monolith. The plasma discharge grew stronger with increased voltage and gas flow rate [1] , [2] , while temperature had adverse effects [3] . The reactor system has been applied to remove NOx [4] and volatile organic compounds (VOCs). This work focuses on removing ethylene (C 2 H 4 ), responsible for the maturity, over-ripening, decoloring, and decaying of fruits and vegetables (FVs), in a high relative humidity environment, which is an essential aspect for the elongation of FVs post-harvest life. Ethylene removal was carried out by a thermally activated catalyst and plasma catalytic oxidation continuous/cyclic process with an average energy consumption of 300 J/L and 105/36 J/L, respectively; the cyclic process being superior to other processes [5] . The novel cyclic process in a honeycomb structured reactor system is advanced-oxidation technology that operates in ambient and low-pressure drop conditions, offers low energy consumption, negligible hazardous by-products, NO x & O 3 , and provides a simple mechanically stable reactor system.