Dampfplasma

Dampfplasma, or steam plasma, denotes a plasma state formed in steam or water vapor. It is an ionized gas in which water vapor and its fragmentation products—such as hydrogen, hydroxyl, and atomic oxygen—are major chemical constituents. Depending on the generation method and operating conditions, the plasma can be near thermal equilibrium or non-thermal, with electron temperatures significantly higher than the gas temperature. This non-equilibrium character yields high chemical reactivity at relatively low bulk temperatures, producing reactive species such as OH, H, and O that drive subsequent chemical reactions.

Generation and chemistry: Steam plasmas are produced by electrical discharges in humid gas (for example, dielectric barrier discharges and arc discharges in steam or humid air), by microwave or RF plasmas in steam, or by plasma torches that introduce steam into a discharge. Water vapor affects the plasma chemistry by facilitating dissociation and radical formation; the resulting composition depends on pressure, power, steam fraction, and residence time.

Applications and challenges: Potential applications include plasma-assisted steam reforming and gasification of hydrocarbons to produce hydrogen or syngas, plasma-enhanced combustion and ignition, surface modification and sterilization, and treatment of wastewater or exhaust gases. Steam plasmas can enable fast reaction rates via reactive OH and H species, sometimes at lower bulk temperatures. Challenges include controlling the complex chemistry in the presence of condensation, electrode erosion and corrosion from high-temperature steam, and the difficulties of diagnostic measurements and predictive modeling.