The iron and steelmaking sector is one of the largest industrial sources of greenhouse gas (GHG) emissions, generating about 7% of the global CO₂ emissions. On average, one ton of steel results in the release of 1.8 tons of CO₂ are emitted. Since 2000, global steel production has more than doubled, reaching 1.88 billion tons in 2023. Steel production is expected to reach 2.5 billion tons by 2050, with a corresponding increase in GHG emissions. The majority of these emissions stem from the blast furnace (BF) – basic oxygen furnace (BOF) steelmaking process, which relies heavily on fossil coal and accounts for about 70% of global steel production. As part of the European Union commitment to the Paris Agreement, the European Green Deal aims to reduce GHG emissions by 55% by 2030 compared to 1990 levels and achieve net-zero emissions by 2050.

            In the steel industry, one effective way to decrease CO₂ emissions is to reduce the use of fossil coal. In this aspect, the LIFE Smart project was created to replace a part of the coal used in steel manufacturing by non-conventional greener reductants, such as waste wood and non-recyclable waste plastics. This approach can contribute in several ways to a more sustainable production process in comparison to traditional coke-making processes: First, it reduces carbon emissions by lowering the demand for fossil coal, thereby cutting both indirect emissions from coal mining, transport, and processing, and direct emissions due to the biogenic carbon content in waste materials. Second, incorporating non-recyclable waste plastics into the steelmaking process recovers both energy and reductive value, offering a more sustainable alternative to incineration or landfill disposal, which have significant environmental drawbacks like soil pollution, groundwater contamination, and methane emissions. Finally, this approach provides economic benefits to steel manufacturers by reducing coal costs and lowering the need for CO₂ emission allowances. However, as these technologies are in the deployment phase, with a technology readiness level (TRL) of 7-8, it is crucial to thoroughly assess their technical and economic viability using real industrial data.

            In this context, our research aims to evaluate the economic and technical impacts of two specific changes in the steelmaking process: first, substituting 2 wt% of coking coal with non-recyclable waste plastics in the production of metallurgical coke, and second, replacing 40-50 wt% of the pulverized coal used in blast furnaces with a torrefied mixture of waste wood and non-recyclable plastics. These modifications are currently being tested and implemented at the ArcelorMittal Gent plant in Belgium as part of the LIFE Smart project. This innovative and cleaner steel production method has the potential to be adopted by other European plants, significantly contributing to the overall effort to reduce emissions.