Microwave Plasma Hydrogen Production

Effective energy sources alternative to fossil-based fuels become the main area of research for sustainable energy development. The declining reserves of fossil fuels and the thread of global warming impose that the newly developed energy source must simultaneously meet the requirements of being renewable and ecological. In this aspect hydrogen (H2) is one of the most promising renewable and environmentally clean energy sources.
Although H2 has a high combustion heat, it is envisaged to be used in the future as an energy carrier for activating the fuel cells rather than a fuel for heat production through the combustion. The applicability of hydrogen for fuel cells boosts an interest in new sources and production methods of hydrogen.

Presently, hydrogen is produced by fuel processing technologies converting different hydrocarbons into hydrogen rich stream. The main conventional techniques used to produce hydrogen from hydrocarbon fuels (steam reforming, partial oxidation, and autothermal reforming) have problems like catalyst poisoning, size and weight requirements, compactness, dynamic behaviour (sluggish response), and limitations on hydrogen production from heavy hydrocarbons.

In the plasma, the overall reforming reactions are in fact the same as in conventional reforming, but the energy and the free radicals used for the reforming reaction are provided by the plasma itself. The plasma eliminates the need for a catalyst in the systems. It plays a catalytic role because highly active species such as electrons, ions and radicals may significantly enhance the reaction rate. Plasma systems can be applied to various hydrocarbons including natural gas, gasoline, heavy oils, and bio fuels, as well as biomass. Biogas is regarded as a new ecological and renewable hydrogen source. It becomes an alternative for methane (CH4), which has so far been a common hydrogen source. Biogas is a gas formed during the breakdown of organic matter in the absence of oxygen. It can be produced from raw materials such as green waste, household waste, agricultural waste, municipal waste, sewage etc. . Biogas is a hydrogen carrier similar to fossil natural gas. Moreover, the plasma high energy density leads to compactness of the system and fast response times can be achieved due to the electrical operation of the system. Generally, non-thermal plasmas due to their non-equilibrium properties have low power requirements and capacity to induce physical and chemical reactions in gases at relatively low temperature.