Computational fluid dynamics analysis of biochar combustion in a simulated ironmaking electric arc furnace

The most urgent concern confronting the steel industry in the twenty-first century is climate change. The Electric Arc Furnace (EAF) is the second most common process in steelmaking, accounting for 29% of the total global production of crude steel in 2018. More than 40% of energy in current EAFs originates from chemical sources of fossil fuels: natural gas and coal. Reducing greenhouse gas emissions (GHG) in the steelmaking process necessitates the development of breakthrough technologies and operational strategies. The use of biochar from torrefaction, slow pyrolysis and hydrothermal carbonisation (HTC) of biomass as a substitute for fossil coal in EAF was investigated in this research. A three-dimensional computational fluid dynamics (CFD) model for combustion and electrode radiation inside an EAF was developed by assuming particle surface and gas-phase reactions to predict injected biochar particle combustion. The effect of the combustion reaction on the temperature distribution inside the EAF and the influence of intermediate gas release was analysed. Results showed that the use of biochars instead of fossil coal in the EAF steelmaking process did not involve significant negative differences. CFD can be a useful and reliable support for guiding adequate EAF process and injection design in a more ecofriendly scenario.

Automated summary

The most urgent concern for the steel industry is climate change. This study investigated the use of biochar as a substitute for fossil coal in the EAF steelmaking process and developed a CFD model to analyze the combustion reaction.