Plasma catalytic reforming of methane

Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This article describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius), and a high degree of dissociation and a substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (40% H-2, 17% CO2 and 33% N-2, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2-3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg Hz with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content (similar to 1.5%) with power densities of similar to 30 kW (HZ HHV)/1 of reactor, or similar to 10 m(3)/h Hz per liter of reactor. Power density should further increase with increased power and improved design. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.