RESUMO

Depollution process by DBD reactor has been developed in air with toluene, a mono-aromatic molecule that simulates volatile aromatic pollutants (VOCs). The objective of the study is to understand the role of active oxygenate species produced by streamers in oxidation and polymerisation mechanisms of aromatic and polyaromatic compounds. A multi-point-to-plane plasma reactor is used. Discharge is produced by an AC 45 kHz HV generator and is electrically characterized by a 0.5 GHz numerical oscilloscope. An O₂ (10%vol), H₂O (1,8%vol), 700 or 300 ppmv toluene in N₂ mixture is treated at atmospheric pressure and 100°C. A qualitative and quantitative chemical analysis of gas effluent and suspended particles is realized by Gas Chromatography coupled with a Mass Spectrometer in order to understand the pulsed discharge chemical reactivity. Alkanes, alkenes, oxidized molecules such as acetone and benzaldehyde, R-NOx (C₂H₅NO₂, CH₃ONO₂) and heavy molecules such as octadecane-2-methyl, methylolpinene or anthracene have been identified. Labeled molecules, ¹⁸O₂ and (C₆H₆)-CD₃, are added in order to identify chemical pathways, especially toluene destruction. The active species coming from air oxygen lead to oxidation reactions with carbon chain cleavage whereas oxidants coming from H₂O lead rather to addition reactions.