Water vapor plasma torch for synthesis gas production from organic waste

Plasma technologies have many fields of application, especially for treatment of materials and waste conversion. Water vapor plasma has special properties of high enthalpy and high activity flow. It can be a promising technology for gaseous, liquid and solid waste treatment and production of synthetic hydrogen-rich gas [1,2]. Atmospheric pressure water vapor plasma technology has been realized at Lithuanian Energy Institute, Plasma Processing Laboratory as an alternative to other reforming methods producing synthetic gas. An experimental linear, sectional, direct current arc plasma torch 55-70 kW of power with copper anode was developed and manufactured. The main plasma forming gas is overheated water vapor, produced by 5 bar of pressure steam generator. The operational characteristics of stable work of water vapor plasma torch were established. The flow was heated up to 2000-3000 K of temperature, the fuel conversion process from liquid organic waste, such as toluene and glycerol in plasma-chemical reactor was realized. Hydrogen and carbon monoxide gases (H₂+CO) were produced as main products, additionally small amounts of CO₂ and C_xH_y were obtained. The investigations confirmed that the conversion of toluene and glycerol into synthesis gas by means of atmospheric pressure water vapor plasma torch was successful. Liquid waste conversion rate exceed 100%. The main products of thermal plasma treatment are H₂ (max. 56.9%) and CO (max. 20.7 %) with relatively high concentrations of CO₂ (up to 12.6%). The results will be useful projecting new plasma equipment, designed for the decomposition of biomass and organic waste.