Decomposition of ethane in atmospheric-pressure dielectric-barrier discharges: Experiments

It is well known that electric fields can influence combustion processes. When the magnitude of an external applied electric field exceeds the breakdown field of the fuel gas or fuel/oxidizer mixture, plasma effects dominate. The earlier work in the field of plasma-assisted combustion has demonstrated that dielectric-barrier-discharge (DBD)-driven nonthermal plasmas (NTPs) can increase flame speed and extend the combustion of hydrocarbon fuel gases into very lean-burn regimes. In this paper, results on the decomposition of ethane (C2H6) by DBDs at atmospheric pressure will be presented. The authors have chosen ethane for this paper because its gaseous electronics properties (electron-impact dissociation cross sections, drift velocity) are available in the literature. A subsequent paper will present results on the calculated yield of DBD-driven plasma decomposition products of ethane, as predicted by plasma-chemistry modeling. In this paper, results on experiments carried out to determine the decomposition products of ethane, as measured by gas chromatography are presented. An atmospheric-pressure DBD reactor processed a flowing gas stream of chemically pure ethane in the regime of plasma specific energy ranging from 1200 to 2400 J/std lit. The major stable decomposition products were H-2, CH4, C2H2, and C2H4. These results are important in assessing the possibility of using NTPs to enhance the combustion of hydrocarbons.