Decarbonising the iron and steel sector for a 2 °C target using inherent waste streams

The iron and steel industry is emissions intensive. Here the authors explore its decarbonisation potential based on recovering energy and recycling materials from waste streams in 2020-2050. 28.5% of CO2 emissions under sectoral 2 degrees C target requirements can be reduced in a high-potential pathway. The decarbonisation of the iron and steel industry, contributing approximately 8% of current global anthropogenic CO2 emissions, is challenged by the persistently growing global steel demand and limitations of techno-economically feasible options for low-carbon steelmaking. Here we explore the inherent potential of recovering energy and re-using materials from waste streams, high-temperature slag, and re-investing the revenues for carbon capture and storage. In a pathway based on energy recovery and resource recycling of glassy blast furnace slag and crystalline steel slag, we show that a reduction of 28.5 +/- 5.7% CO2 emissions to the sectoral 2 degrees C target requirements in the iron and steel industry could be realized in 2050 under strong decarbonization policy consistent with low warming targets. The technological schemes applied to engineer this high-potential pathway could generate a revenue of US$35 +/- 16 and US$40 +/- 18 billion globally in 2035 and 2050, respectively. If this revenue is used for carbon capture and storage implementation, equivalent CO2 emission to the 2 degrees C sectoral target requirements is expected to be reduced before 2050, without any external investments.

Automated summary

This article explores the decarbonization potential of the iron and steel industry by recovering energy and recycling materials from waste streams. It suggests that a reduction of 28.5% in CO2 emissions can be achieved through this approach, and proposes using the generated revenue for carbon capture and storage implementation.