Experimental study of hydrogen plasma reforming by intermittent spark discharges

We present an experimental analysis of an air/methane high voltage discharge at atmospheric pressure which operates in an intermittent spark regime. The aim is to study the feasibility of hydrogen reforming through plasma processing. The structure of the spark and the electrical characteristics of the discharge have been studied as a function of the air/methane mixture composition, the gas flowrate, the average current and the external circuitry resistance. Discharge spectra in visible and near ultraviolet range show the production of several radicals and excited species which provide a clue on the relevant chemical kinetics in the plasma state. Detailed mass analysis of the composition of the exhaust gas flow, shows significant production of hydrogen and high conversion efficiency of methane. The dependence on the discharge operating parameters has been investigated in order to clarify the optimal setup design for an efficient plasma reformer.