Incorporating composition into life cycle assessment of steel grades

Steel is a vital material in modern industries due to its versatility and remarkable properties. In a world that is increasingly concerned about the environment, it is necessary to incorporate good practices that help reduce the environmental impact of our economies. An important aspect is evaluating the environmental impact of materials throughout their life cycle. However, calculating this impact using generic databases can be challenging, as they may lack the necessary specificity. To obtain more accurate environmental impact calculations, it is essential to consider the composition of the materials. Each steel grade, for example, can vary in the content of alloying elements, which influences its environmental impact. Therefore, particularising calculations based on compositions is essential for making informed and sustainable material selection decisions. This article presents a calculation methodology to establish a Life Cycle Inventory of steel, emphasising the specific composition and using datasets of steel production in a Basic Oxygen Furnace (BOF) developed by ecoinvent as reference. The methodology presented seeks to allow the systematic calculation of the environmental impact of any steel considering its composition, contribute to the incorporation of environmental criteria in the selection of materials, and quantify the content of critical raw materials according to the latest report published by the European Union. Likewise, a case study is included, in which the composition's influence on the environmental impact of 10 steel grades widely used in induction cooktops has been analysed. • Alloy compositions highly influence the environmental impact of steel grades. • Methodology for environmental impact assessment since the chemical composition of steel. • Impact variations of up to +348%, depending on the steel grade, have been found. • A more accurate environmental impact contributes to sustainable material selection.