Integrating optimization and LCA models in the steelmaking process: insights from the ALCHIMIA project

Improving the sustainability of the steelmaking sector is a challenging task because steelmakers are expected to meet environmental targets and strict quality requirements that depend on the final application of the product. Recycling steel in electric arc furnaces (EAFs) is a well-established circular practice that helps reducing the environmental impact of steelmaking. However, an optimal combination of different scrap types and additions, along with minimum electricity and gas consumption during the melting phase, is necessary to ensure high quality and environmental performance of final products. The process input mix can be improved by exploiting optimization tools and Life Cycle Assessment (LCA) to minimize a multi-objective function including environmental impacts, constrained by technical requirements of steel and process operating conditions. The paper presents a methodology to transform “traditional” LCA into an “optimized LCA approach”, focusing on how Life Cycle Inventories and Life Cycle Impact Assessment can be associated to optimization variables or inputs, depending on steelmakers’ ability to affect EAF-based steelmaking operational parameters. The discussion highlights opportunities and limitations of integrating LCA and optimization methodologies within the framework of a real-world case study carried out in the European project ALCHIMIA.