Efficiency of biomass use for blast furnace injection

Abstract

Numerous studies and available experience proved the feasibility and benefits of the biomass usage in various metallurgical applications, particularly, by its injection into the blast furnace (BF). This contribution focuses on three aspects, which could increase the economic efficiency of this technology. The first one is related to the thermal treatment of biomass. Woody biomass were pyrolysed using a laboratory pyrolysis plant under different conditions resulting in various amounts and properties of solid, liquid and gaseous constituents. Co-injection of the produced charcoal and biogas into the BF was proposed. Mathematical modelling using the experimental data of mentioned biomass product characteristics was undertaken to examine the effect of this technology on the BF operation results. The second aspect is related to the optimisation of grain size and size distribution of injected solid biomass products. Tests using a laboratory injection rig allowed for recommendation of the coarser grinding of charcoal than that for fossil coal applied for the BF injection. This could lead to the additional energy and cost saving. The third aspect concerns the improvement of the BF control. It is proposed a new BASE1 method for the BF thermal state control by adaption of the pyrolysis parameters while injecting pyrolysed biomass and coupling the blast furnace with a pyrolysis reactor.