(299ab) Hydrogen Production from Natural Gas Reforming in Gliding Arc Discharge

Natural gas resources with high concentrations of carbon dioxide have been found in several areas, especially the Southeast Asia countries including Thailand. The reforming of methane with carbon dioxide should be a promising way to directly utilize the natural gas without any prior separation process, resulting in it being more economical in terms of cutting down the high cost of an additional separation unit and reducing the net emission of carbon dioxide as a greenhouse gas. The objective of the present work was to study the reforming of simulated natural gas via the nonthermal plasma process with the focus on hydrogen production. The reforming of simulated natural gas was conducted in an alternating current (AC) gliding arc reactor under ambient conditions. The feed composition of the simulated natural gas contained a CH₄/C₂H₆/C₃H₈/CO₂ molar ratio of 70/5/5/20. To investigate the effects of all gaseous hydrocarbons and CO₂ in the natural gas, the plasma reactor was operated with different feed compositions: pure CH₄, CH₄/He, CH₄/C₂H₆/He, CH₄/C₂H₆/C₃H₈/He and CH₄/C₂/H₆/C₃H₈/CO₂. In comparisons among all the studied feed systems, hydrogen yield was found to depend on the feed composition in the following order:CH₄/C₂H₆/C₃H₈/CO₂ > CH₄/C₂H₆/C₃H₈/He > CH₄/C₂H₆/He > CH₄/He. The maximum hydrogen yield, about 35%, was found in the CH₄/C₂H₆/C₃H₈/CO₂ system. In terms of energy consumption for producing hydrogen product, the system of CH₄/C₂H₆/C₃H₈/CO₂ feed mixture required the lowest input energy in the range of 3.58x10^-18-4.14x10^-18 Ws (22.35-25.82 eV) per molecule of hydrogen produced.