Hydrogen Production via Partial Oxidation Reforming of Methane with Gliding Arc Discharge Plasma

Hydrogen production from partial oxidation reforming of methane in a gliding arc discharge (GAD) reactor is investigated. The effects of input power, the oxygen-carbon molar ratio (O/C), and residence time are studied, respectively. Products such as H-2, CO, CO2, and C-2-C-4 hydrocarbons can be detected in the outlet gas. The experimental result shows that the input power of 36.4 W, the relitively low O/C of 0.705 and the 13.8 s residence time in this system will bring the highest H-2 energy yield. Compared to the decomposition of methane, partial oxidation of methane with air can maintain a stable discharge state and no carbon deposition on electrodes is observed during the reaction process. Optical emission spectroscopy (OES) is also employed to characterize this methane-air plasma. Based on the results of the experiment and OES, a possible mechanism of methane partial oxidation process was proposed, which points out that collisions of high-energy electrons and excited N-2 species (mainly N-2(A)) with other species (such as O-2, CH4) in the plasma region are two main ways for the activation of this reforming system. Hydrogen is generated principally through the H-abstraction reaction and the H-coupling reaction.