Blast Furnace Emission Reduction Potential by Charcoal Injection

Abstract

One of the most important uses of coal is within the iron and steel sector for iron ore reduction. The iron and steel industry is under a great pressure to decrease its emission intensity to slow down the global temperature rise, and substitution of sustainably sourced charcoal for pulverized coal injected (PCI) into the blast furnace has been proposed as one of the short term emission reduction strategies. This paper evaluates whether substitution of sustainably sourced charcoal for PCI would present a net benefit, even during the worst case scenario, and hence evaluate whether the switch should be supported from an environmental perspective. The analysis was done for two boundaries, i.e. a boundary focusing only on the on-site emissions and a boundary focusing on both on-site and off-site emissions. Those boundaries could be compared to Scope 1 and 3 of the Greenhouse Gas Protocol, respectively, if the coal was the only fuel or material that the plant operates with. The results show that even in the worst case scenario, usage of sustainably sourced charcoal would never be worse – from the environmental perspective – than PCI. On average, use of charcoal can offset between 16-21% of the carbon emissions occurring due to iron and steel production within each boundary. The greatest emission savings per tonne of crude steel (tCS) could be expected within boundary B, when by-product credits from charcoal production are also considered.