Oxidation System of Adsorbed VOCs on Adsorbent Using Nonthermal Plasma Flow

A toluene oxidation system is developed using an adsorbent and a nonthermal plasma (NTP) flow that consists of a surface discharge and a circulation flow. The liquid toluene is vaporized in the circulation line connected with a blower, the adsorbent, and the surface discharge plasma reactor in series, and the toluene gas is adsorbed by the adsorbent. Hydrophobic zeolite pellets are used as the adsorbent. After the toluene adsorption, ozone generated by the surface discharge is supplied to the adsorbent, and adsorbed toluene is oxidized on the surface of the adsorbent. Because the gas is circulated during toluene oxidation, ozone is used to oxidize toluene effectively and without waste. As a result, adsorbed toluene is efficiently converted to CO_x (CO + CO₂) using the NTP flow; 88% and 43% conversion ratios of toluene to CO_x are achieved when 1 and 6 mL of toluene are oxidized for 90 and 150 min, respectively. In addition, CO₂ selectivity of more than 89% is obtained when 1 and 6 mL of toluene are oxidized. The conversion rate of toluene to CO_x and the energy efficiency of the toluene-to-CO_x conversion increase with the amount of adsorbed toluene.