Reforming of methane and carbon dioxide by DC water plasma at atmospheric pressure

An experimental plasma chemical reactor, equipped with a novel water plasma torch, was used for reforming methane and carbon dioxide mixture to produce synthesis gas (syngas). Water plasma is generated by the torch at atmospheric pressure, in the absence of carrier gases, water cooling system and special steam supply system. The influence of the ratio of CO2 to CH4 and total feed gas rate on syngas production, composition and energy conversion efficiency were investigated. Compared to other plasma technologies, the higher reaction performance was obtained by the novel water plasma process. The results show that, under optimum experimental conditions, the energy conversion efficiency reaches up to maximum value of 1.87 mmol/kJ and the highest energy efficiency of 74.63% is achieved, which is higher than that of other plasma processes. Furthermore, the obtained syngas with high mole ratio of H2 to CO (close to 2) is suitable for the direct industrial application.

► A novel water plasma torch is firstly employed to convert methane and carbon dioxide to syngas at atmospheric pressure.
► Parametric studies were achieved to determine reforming characteristics in the water plasma torch reformer.
► High energy efficiency of 74.63% is achieved.
► A relatively high mole ratio of H2 to CO (about 2) in syngas is obtained.