Carbon Footprint of Alloyed Crude Steel in Germany: Focusing the Influence of Different Alloying Recipes

Abstract The aim of this study is the determination of the carbon footprint of alloyed crude steel according to ISO 14067, considering all different alloying recipes as sold by a German integrated steel mill. All relevant foreground data have been collected directly from a steel mill based on the declared unit of 1000 kg of alloyed crude steel. Particular attention was paid to the influence of 560 different steel grades on the total carbon footprint of steel within the sensitivity analysis. The total global warming impact (GWI) of producing 1000 kg of alloyed crude steel amounts to 2050 kg carbon dioxide equivalents (CO 2 eq.). On average, 90 kg CO 2 eq. are attributed to the alloying elements. However, depending on the alloying recipe, the contribution of the alloying elements to the steel's total GWI can range from 20 to over 500 kg CO 2 eq. of additional greenhouse gas (GHG) emissions. The study's findings provide a detailed assessment of a variety of different steel grades by highlighting potentials for reducing GHG emissions associated with current iron and steel production. Therefore, a novel insight into the GHG emissions of steel is provided by quantifying the impact of steel quality on the GHG emissions for the entire product portfolio of a steel mill in Germany. Graphical Abstract