Steam Plasma Flows Generated in Gerdien Arc: Environment for Energy Gas Production from Organics and for Surface Coatings

Abstract

Electric arc stabilized by a vortex of water (Gerdien arc) is used in a special type of plasma torch for generation of thermal plasma jet with extreme plasma parameters. Extremely high plasma enthalpy and plasma temperature and very low plasma density result in very high efficiency of utilization of plasma enthalpy for heating of material injected into plasma. Plasma torches with Gerdien arc are used in industrial scale for plasma spraying, other plasma chemistry applications like waste treatment or gasification of biomass for syngas production are being investigated. In these applications, special properties of steam plasma produced in this type of arc are beneficial. Experiments with steam plasma gasification of carbon containing materials were made in plasma reactor with Gerdien arc plasma torch. Gasification of polyethylene, plastic waste, wooden pellets and saw dust were studied for arc power 100 - 140 kW. Syngas with high content of hydrogen and carbon monoxide and very low content of carbon dioxide was produced. Very low content of complex hydrocarbons and tar was detected. In optimal conditions the calorific value of produced syngas was substantially higher than electric energy spent for plasma generation. Possibility of usage of the process is discussed for energy storage during excess of electricity available from power plants with fluctuating output.