Steel Manufacturing EAF Dust as a Potential Adsorbent for Hydrogen Sulfide Removal

Abstract

Electric arc furnace dust (EAFD) is a high-volume steel manufacturing byproduct with currently limited value-added applications. EAFD contains metal oxides that can react with H ₂S to form stable sulfides. Hence, the valorization potential of EAFD as an adsorbent material for syngas H ₂S removal was investigated. EAFD from European steel plants was characterized and tested in dynamic H ₂S breakthrough tests and benchmarked against a commercial ZnO-based adsorbent. For this, the EAFD was first processed into adsorbents by simple milling and granulation steps. The EAFD samples exhibited sulfur capture capacities at 400 °C and an SV of 17,000 h ^–1 that correlated with the sample milling times and Zn concentrations. It was verified that only zinc participated in sulfur capture. Yet, both ZnO and the zinc in ZnFe ₂O ₄ were found to be active in sulfidation. At higher temperatures (500 and 600 °C), EAFD sample performance drastically improved and even exceeded the reference zinc oxide performance. The high-zinc (48% by mass) EAFD-B sample exhibited the highest tested performance at 500 °C, with a sulfur capture capacity of 234 mg g ^–1. The results indicate that sufficiently high-zinc-content EAFD could serve as a viable sulfur capture material.