Hazardous waste treatment and recovery of valuable products with a thermal pulsed-plasma technology

Material decomposition is an essential process in chemical industries. A new, efficient and environmentally friendly technique that can be used in a closed-loop process for the treatment and recovery of materials is described. The idea is to decompose a material using a high-energy pulsed-plasma jet. The plasma specific features enable an efficient radiative heat transfer to the treated material bed. Therefore, enhanced energy transfer to selected chemical bonds is achieved. The process can be defined as a highly efficient photolysis. Proof-of-concept tests were carried out on 1,2-Dichloroethane (DCE) fed in batches of a few grams each. A total decomposition of the DCE was achieved with less than 60% of the energy consumption required in a conventional treatment. In the current project, a modular transportable laboratory has been constructed. It comprises a 30 kW pulsed power supply featuring an all-solid state power switching system, confined plasma injector, reactor and gas handling and monitoring systems. The expected treatment capacity is 10 kg/h of fluid waste with expected lifetime of the plasma injector of 105 pulses. Simulations and experimental characterization of major components are presented. It is expected that the proposed method will be the Best Available Technology (BAT-as defined by the European Union regulations) for many fluid wastes.