Optimal Resource Allocation in Integrated Steelmaking with Biomass as Auxiliary Reductant in the Blast Furnace

Abstract

An integrated steel plant with two blast furnaces with the option to use biomass to partially substitute fossil reductants was simulated. A thermodynamic blast furnace model was used, combined with simpler models of the other unit processes (sintermaking, cokemaking, basic oxygen furnace, hot stoves and power plant) and a nonlinear model of the biomass conversion with respect to the processing temperature. Given an aim steel production rate for the plant, the economics of the plant was optimized by minimizing the specific costs of liquid steel, considering costs of raw materials, energy and CO2 emissions. Limited supply of sinter and coke was optimally allocated to the two blast furnaces and the effects of restrictions in the biomass, oxygen and oil supply on the operating states were studied. An analysis was also undertaken to study how the production rate of the plant would affect the optimal state. The results demonstrate that a non-uniform distribution of the resources can be economically justified, in particular for cases where the blast furnaces operate under different constraints.

Charcoal injection in blast furnaces (Bio-PCI): CO2 reduction potential and economic prospects

“…A third kind of framework is been used by Saxen et al [29], Helle et al [30], and Wikulund et al [31,32] in the assessment of the economic potential of biomass utilization in a steel plant. Originally this method has been used for the analysis of the economic prospects of technological innovations in steelmaking (see Pettersson and Saxen) [33].…”

“…The costs absent in the model are: capital charges, hand labour, ferroalloys, refractories and raw material transportation to the plant. Secondly, in the previous works [29][30][31][32], the biomass pyrolysis is performed in the steelwork, while in practice charcoal manufactures are separate entities of production. Finally, the finding of previous authors appeared to be based on arbitrary selected raw materials prices, with no relation to actual raw materials cost.…”

The effect of feedstock origin and temperature on the structure and reactivity of char from pyrolysis at 1300–2800 °C

“…In recent years, many studies investigated production and/or co-production of carbonaceous solids by pyrolysis treatment of wide variety of renewable feedstocks [3,5,[7][8][9][10][11]. In comparison with the metallurgical coke traditionally used in ferroalloy production, carbon produced from renewable feedstocks contains less fixed carbon and a greater percentage of volatile components and may need to be graphitized prior to use as a reductant [11].…”

Influence of biomass on metallurgical coke quality

“…Integrated steel works generate a large amount of CO 2 due to their use of fossil fuels either as a reductant or as a fuel. It has been estimated that its contribution to total anthropogenic CO 2 emissions is about 6.5 % [1][2][3][4]. It has been proposed that fossil fuel be replaced by reductants which are more environmentally friendly.…”