We have previously cited, as in "Methane conversion to higher hydrocarbons in the presence of carbon dioxide using dielectric-barrier discharge (DBD) plasmas; Plasma Chemistry & Plasma Processing, 2001",
and will further cite, the work of Swiss scientist Baldur Eliasson and his Chinese co-workers in the field of Carbon conversion technologies.
Herein, Eliasson, et. al., reveal, in confirmation of previous reports we've submitted, that Methane, as can be synthesized from Carbon Dioxide, via Sabatier-type reactions, or from Coal, via hydrogasification, can serve to improve the production and efficiency of some indirect Coal-to-liquid conversion processes.
Our understanding, from other references, is that the word "plasma", as it is used herein and as applied in these technologies, refers to a, relatively, "low-temperature" gas chemistry phenomenon, and does not imply the high-temperature, high-energy processing environments which might normally be associated with plasma phenomena.