Electric arc furnace dust as an alternative low-cost oxygen carrier for chemical looping combustion

Abstract

The relative abundance and low cost of electric arc furnace dust (EAFD) make it a viable oxygen carrier for chemical looping combustion (CLC) system. Under a reducing agent, zinc ferrite (ZnFe₂O₄) phase in EAFD releases zinc vapor in a complex gas-solid reaction. In an effort to suppress the emission of zinc vapor, the reaction mechanism of ZnFe₂O₄ prepared as an oxygen carrier in a redox cycling test is primarily discussed, as well as the issue of coupling with an inert Al₂O₃ support. The study focused the investigation on redox cycling behavior and CO2 conversion in ZnFe₂O₄/Al₂O₃ and EAFD/Al₂O₃ systems using a thermogravimetric analyzer (TGA) and fixed-bed reactor (FxBR). In a lab-scaled semi-fluidized bed reactor (semi-FzBR) of EAFD/Al₂O₃ as an oxygen carrier system, a high CO gas yield approximately 0.98 after fifty redox cycles is also experimentally obtained. It can be anticipated that the use of EAFD/Al₂O₃ system as an oxygen carrier in a reversible CLC process could be economical and environmentally beneficial.

Keywords: Chemical looping combustion; Electric arc furnace dusts; Oxygen carrier.