Decomposition of Adsorbed Xylene on Adsorbents Using Nonthermal Plasma With Gas Circulation

A xylene decomposition system that combines a process of adsorption with a process of decomposition by nonthermal plasma with gas circulation is investigated for treating volatile organic compounds exhaust from indoor small-scale sources. An ac 60-Hz neon transformer and an inverter-type neon transformer are used for the generation of the nonthermal plasma. After p-xylene or a xylene mixture consisting of o-, m-, and p-xylene is adsorbed by an adsorbent, nonthermal plasma is generated with gas circulation, and adsorbed xylene is decomposed. The performance of this system is evaluated in terms of the conversion ratio of adsorbed xylene to CO and CO2 and the energy efficiency of the xylene decomposition process. The energy efficiency of the xylene decomposition process carried out using the inverter-type neon transformer is found to be better than that of the process carried out using the ac 60-Hz neon transformer. However, the stable operation of the plasma reactor is difficult, and a large amount of NOx is generated as a byproduct when the inverter-type neon transformer is used. Thus, the results obtained in this research suggest that the ac 60-Hz neon transformer is suitable for this system.