Methane Conversion into C2 Hydrocarbons and Carbon Black in Dielectric-barrier and Gliding Discharges

The methane conversion into C-2 hydrocarbons, carbon black, and hydrogen was studied under plasma conditions at atmospheric pressure using dielectric barrier discharges (DBD) and gliding discharges. Ethane was the main product of the methane conversion under the filamentary DBD action in the mixtures CH4+Ar, thus it may be concluded that under the conditions of DBD microdischarges, the methane transformation can be terminated after one of the first steps of the chain reaction when ethane is produced. The methane conversion rate increased in the presence of dielectric granular packing (quartz glass and silica gel). Using the gliding discharges, two processes were examined: the methane conversion into unsaturated hydrocarbons C-2 (mainly acetylene) and into carbon black. For these processes, it was found that the methane concentration in the starting gas mixtures (CH4+H-2 and CH4+Ar) is one of the main parameters influencing the conversion rate and the unit energy consumption. The equilibrium in the CH4+H-2 mixtures at the pressures of 1 and 10 bar was examined and the temperature ranges of the solid carbon stability were determined.