Vol. 11, No.2, pp.150-155 (2018)
Direct Conversion of Methane with Non-Thermal and Thermal Plasmas
Y.-H. Song, H. S. Kang, D. H. Lee, W. S. Kang, and S. Jo
Plasma Engineering Laboratory, Korea Institute of Machinery & Materials, Korea
Abstract
Direct conversion of methane with non-thermal and thermal plasma has been investigated; in the case of non-thermal plasma, two different issues were investigated; effects of beads in a DBD (Dielectric Barrier Discharge) reactor and effects of noble gases (He, Ne, Ar, and Kr) on the methane conversion, respectively. A study of DBD reactor packed with alumina beads showed that the conversion process is enhanced by the packed beads, and revealed that this favorable effect is attributed to the increased electrical fields near the points of contact between the beads. The noble gases also play a role to increase the conversion. Theoretical analysis showed that various reaction pathways are involved in this enhancement of the conversion process, such as direct dissociation of methane molecules with energetic electrons, methane activation by meta-stable state noble gases and ions. A study of high-temperature pyrolysis with a rotating arc was also conducted, which found that it can produce sufficiently high methane conversion and selectivity for C2 hydrocarbons to consider it for practical applications. This comparison of non-thermal and thermal plasma therefore provides a good insight into the plasma methane conversion process.
Keywords - Direct methane conversion, non-thermal plasma, thermal plasma, energetic electrons