DiGiovanni, et al (2024) An Experimental Setup and Investigation on BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More Blends for Slag Foaming Applications. 13th European Electric Steelmaking Conference.

In electric arc furnace (EAF) steelmaking, injecting carbon into molten slag is essential for slag foaming, which boosts energy efficiency and protects the furnace. Traditionally, fossil fuels like petroleum coke (petcoke) are used for this process. However, with the drive for decarbonization, biochar is gaining interest as an alternative carbon source.

A recent study explored the performance of biochar and petcoke blends for slag foaming. Using a lab-scale setup, experiments simulated steelmaking conditions with different carbon ratios: 100% petcoke, 100% biochar, and blends of the two. Thermogravimetric analysis (TGA) showed that biochar is more reactive, leading to rapid initial carbon monoxide (CO) gas generation. However, biochar’s foaming effect dissipated quickly due to inconsistent gas generation, unlike petcoke, which produced steady gas output and longer-lasting slag foams.

The most promising results came from a 50/50 blend of petcoke and biochar. This combination matched the foaming duration of petcoke while exceeding its foam height, suggesting a synergistic effect. The blend harnesses biochar’s intense initial foaming and petcoke’s sustained performance. Although a 75% petcoke blend showed potential, testing was halted due to safety concerns, leaving the 50/50 mix as the optimal blend for both performance and environmental benefits.

This research highlights the potential of biochar blends to reduce fossil fuel use in steelmaking without sacrificing operational efficiency.