Future potential for biomass use in blast furnace ironmaking

Iron- and steelmaking is an energy intensive industrial sector using mainly coal as the heat source and reduction agent. The industry gives rise to about 7 % of the anthropogenic CO₂ emissions in the world. In the absence of economically feasible and efficient methods of capturing and storing such enormous quantities of CO₂, means for suppressing the emissions must be explored. The work reported in this paper studies the potential of injecting biomass to partially replace fossil reductants in the blast furnace process. The ironmaking blast furnace process is described mathematically by a thermodynamic simulation model, including realistic operational constraints. The model has been applied extensively to evaluate the use of biomass (e.g., wood chips) as auxiliary reductant, creating a simplified linear model on the basis of the results. The model is used to throw light on the feasibility of biomass injection under future price scenarios. Even though the coke replacement ratio of biomass is low, in the order of 25 %, it is demonstrated that the use of biomass as reductant can be a feasible alternative under future price scenarios of coke and emissions.