Utilization of Renewable Carbon in Electric Arc Furnace-Based Steel Production: Comparative Evaluation of Properties of Conventional and Non-Conventional Carbon-Bearing Sources

Abstract

Conventional (anthracite, calcined petroleum coke, and coke) and non-conventional (biochar, and biocokes (3 wt.% torrefied wood, and 3 wt.% petroleum coke + 3 wt.% charcoal)) carbon-bearing sources have been studied for their use in electric arc furnace (EAF)-based steel production. Commonly, for the use of carbon sources in EAFs, one of the important properties is the content of fixed carbon, the release of volatiles as well as the elemental composition of inorganics. The properties of six carbon sources were analyzed by determining the proximate analysis, X-ray fluorescence analysis (XRF), coke reactivity index (CRI), and strength after reaction with CO2 (CSR), Brunauer–Emmett–Teller (BET) specific surface area and Barrett–Joyner–Halenda (BJH) pore size and volume analysis, ash chemical analysis, optical and scanning microscopy, Raman spectroscopy and X-ray diffraction (XRD) analysis. The results indicate biocoke as a promising option to replace conventional carbon-bearing sources. In the sample set, the fixed carbon, volatiles, and ash content of the biocokes were similar despite the total difference in additives. Additionally, the use of additives did not significantly affect the biocoke reactivity indices, but slightly decreased the strength after the reaction with CO2. Carbon-bearing sources have been characterized in terms of their structural properties. XRD analysis revealed that the amount of disordered carbon increased in the order: coke < calcined petroleum coke ~ biocoke (3 wt.% torrefied wood) < biocoke (3 wt.% petroleum coke + 3 wt.% charcoal) < biochar. The results obtained on the physical, chemical, and structural properties of carbon sources are the basis for further research on the behavior of slag foaming.

Potential and Environmental Benefits of Biochar Utilization for Coal/Coke Substitution in the Steel Industry

“…A comparative study on conventional and non-conventional carbon sources (biochar and biocoke) for EAF applications determined biochar as the material with a lower fixed carbon value, with lower ash content and higher reactivity than biocoke [43]. Similar characteristics emerged in other studies [19,31,35,38].…”

Ranking of Injection Biochar for Slag Foaming Applications in Steelmaking

“…Despite biochar presenting great potential to reduce CO 2 emissions from the process, research focused on the use of biochar to replace fossil fuels in EAF steelmaking has been limited. Kieush et al [12] compared the physical, chemical, and structural properties of fossil carbon and biochar. It was determined that biochar had limited use due to its low fixed carbon value.…”

Evaluation of Slag Foaming Behavior Using Renewable Carbon Sources in Electric Arc Furnace-Based Steel Production

“…Aiming to reduce dependence on fossil fuels and decrease the contribution to greenhouse gas (GHG) emissions in EAF steelmaking, various authors have evaluated the slag foaming phenomenon and the impact on foaming behavior when using non-conventional carbon sources. Generally, studies focus on biochar use [25][26][27] and a mixture of biochar and coke [28]. Further, there are studies on waste plastics and rubber applications [29][30][31].…”