Designing an Experimental Non-Thermal Plasma Reactor for Hydrogen Plasma Smelting Reduction*

The current iron ore reduction process, smelting, takes three main elements: iron oxide (FeOx), limestone, and coke. Overall, the steel industry contributes to about 7% of all greenhouse gas emissions globally and emits hazardous by-products. Hydrogen-Plasma-Smelting-Reduction (HPSR) of FeOx is under consideration to decarbonize the steel industry through electrification. Understanding the fundamental science principles leading a plasma arc to reduce FeOx is the main objective of this BES-funded project. In an attempt to decouple the effect of the heat (~10,000 °C), radicals, excited species and ions on the reduction process, a non-thermal plasma (NTP), dielectric barrier discharge or nanosecond pulsing, coupled with external heat will be designed and investigated. The focus of this research project is the design and build of such a NTP reactor that can accommodate an FeOx pellet, add additional heat to the pellet, and obtain optical emission spectra (OES). Two heating sources are currently being investigated: infrared lamps and resistive heating using a ceramic furnace. Using modeling, we will build a heat map showing the temperature gradient of the gas can reach 300 °C in the pellet. We will construct the device and test whether the additional heat affects the plasma discharge or not. To this end, we will characterize argon (Ar), and hydrogen (Ar/H2) plasmas using OES, and electrical characterization techniques. Once the adequate reactor is identified, it will be used to understand FeOx reduction using NTPs and relate it to plasma parameters that can be extrapolated to plasma arcs.