Non-Thermal Plasma Process for Dilute Trichloroethylene Decomposition with the Help of Manganese-Dioxide Supported Catalyst

Abstract

The atmospheric pressure non-thermal plasma is very active and can decompose various toxic gaseous materials. The authors are engaged in decomposing various VOCs (volatile organic compounds) by using the high pressure non-thermal plasma. In order to improve the decomposition energy efficiency of the plasma reactor, new manganese-dioxide supported alumina spheres of 3 mm in diameter were fabricated as the new catalyst which can decompose the ozone very well even at the room temperature. The non-thermal plasma processed air with/without dilute VOCs contains much ozone which is easily decomposed by that new catalyst. At that ozone decomposition process in the catalyst, trichloroethylene (TCE) is also oxidized very well. That TCE decomposition mechanism is a little bit different with the TCE decomposition by the non-thermal plasma directly. If the specific energy density (SED: input discharge energy, Joule, per 1 litter gas) is only 11 J/L, the TCE decomposition efficiency is more than 99 % in authors experiment. However, the improvement of the carbon balance (more than 99 % carbon of TCE is oxidized to carbon oxide) needs very large SED of 90 J/L at present. Some trials to improve the TCE decomposition efficiency were also examined.