A gliding arc plasmatron (GAP) is used for the production of hydrogen and acetylene via plasma-assisted methane pyrolysis. The working gas consists of argon with variable admixtures of methane. By applying camera measurements and optical emission spectroscopy the temperatures and electron density inside the GAP are measured. Two temperature regions are determined: the filamentary plasma, with 3470–5960 K, and a diffuse region characterized by black body emission of hot carbon containing dust at a temperature of 2230–2770 K. An analysis of the product gas stream shows a maximum methane conversion of 44% at a specific energy input of (Formula presented.) and selectivities towards hydrogen and acetylene between 25%–81% and 75%–89%, respectively.
Böddeker et al. (Wed,) studied this question.