Comparison of catalytic activity of aluminum oxide and silica gel for decomposition of volatile organic compounds (VOCs) in a plasmacatalytic reactor

By reducing the distance between the dielectric end-fittings of a coaxial pulsed corona reactor to values on the order of millimeters, the efficiency of volatile organic compound (VOC) decontamination of atmospheric pressure air could be increased by a factor of seven over that obtained in reactors with electrode lengths in the centimeter range. The increased efficiency is attributed to the increasing effect of surface streamers with increased electron density compared to streamers in the gas space. Packing the discharge gap of the reactor with catalytically active silica gel pellets further increased the energy efficiency of VOCs decontamination by more than 50% over that obtained in the absence of any packing. Silica gel was shown to remove VOC by adsorption until it became saturated. The adsorption provides a tool for handling surplus VOCs under fluctuating input conditions. Destruction of preadsorbed organics on silica gel was also demonstrated. Aluminum oxide pellets showed no catalytic effect on destruction of VOCs under these conditions. Index Terms--Aluminum oxide, benzene, catalysis, hexane, methane, nonthermal plasma, pulsed corona discharges, silica gel, toluene, volatile organic compounds (VOCs).