Thermal plasma technology can be used in the production of hydrogen and hydrogen-rich gases from a variety of fuels. This paper describes experiments and calculations of high-temperature conversion of methane using homogeneous and heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Plasma reformers can be operated with a broad range of fuels, are very compact and are very light (because of high power density), have fast response time (fraction of a second), can be manufactured with minimal cost (they use simple metallic or carbon electrodes and simple power supplies), and have high conversion efficiencies. Hydrogen-rich gas (50−75% H2, with 25−50% CO for steam reforming) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2−3...