Life Cycle Assessment for the electric steelmaking route in the ALCHIMIA project

F. Rossi*1,2, M. Niero1,2, V. Colla3,1, A. Zaccara3, S. Dettori3,1, L. Laid3, F. Iraldo2,1 1Sant’Anna School of Advanced Studies, Sustainability and Climate Interdisciplinary Center, via Santa Cecilia 24, Pisa, Italy 2Sant’Anna School of Advanced Studies, Institute of Management, Sustainability Management Lab, Piazza Martiri della Libertà 24, Pisa, Italy 3Sant’Anna School of Advanced Studies, TeCIP Institute Via G. Moruzzi 1, Pisa 56124 Italy Life Cycle Assessment for the electric steelmaking route in the ALCHIMIA project The ALCHIMIA Project The mission of the ALCHIMIA project is to provide sustainable and competitive metalworking industries in the EU with a platform to support the transition to high-quality, competitive, efficient, and green production processes with the guarantee of high-quality products in the steel-making industry Role of Life Cycle Assessment (LCA) Baseline calculation: benchmarking the environmental performances of the steelmaking processes (Electric Arc Furnaces, EAFs) located in 3 factories owned by CELSA Group, and of one cast iron production process placed in Fonderia di Torbole (FdT) Process optimization: including environmental impact factors of the process in a multi-objective optimization model designed for one of the factories owned by CELSA Group Comparison: comparing the environmental impacts of the process preand postoptimization Methodology 1. Goal and Scope definition: Calculating the main environmental hotspots of the steel produced in CELSA facilities. The results will represent a baseline for the optimization model. 2. Life Cycle Inventory (LCI): The LCI consists of the collection and quantification of materials and energy consumption, the production of waste, wastewater, and emissions involved in the production of steel in CELSA factories. 3. Life Cycle Impact Assessment (LCIA): 7 environmental impact categories are considered to describe the eco-profile of steel products. 4. Life Cycle Interpretation: Results have been calculated and initial recommendations can be provided. The recycling modelling approach The “substitution” recycling modelling approach adopted in ALCHIMA assigns environmental impacts to scrap based on the embodied substances it contains (e.g., iron, copper, manganese). This method also accounts for environmental credits resulting from the recycling of output waste. Transports are also included. This approach was selected because it enables the optimizer to account for the chemical composition of scraps when minimizing environmental impacts. Life Cycle Assessment –CELSA Plants •Functional Unit: producing 1 kilogram of steel, net production •Background Database: Ecoinvent 3.9.1 •LCI: based on primary data collected by CELSA •Impact Assessment method: EF3.1, recommended by the European Commission Life Cycle Inventory flows The following environmental impact categories are considered as the most relevant in the metals sector (Santero and Henry, 2016): Climate Change: this indicator measures of the effects of greenhouse gas emissions to Climate Change [kgCO2 eq] Acidification : this indicator measures the effects of acidic substances on the environment, particularly on soil and water, which can disrupt ecosystems and harm living organisms [mol H+ eq] Eutrophication (marine, freshwater, terrestrial): this indicator measures the level of nutrients released into water bodies through human activities, leading to excessive algae growth, oxygen depletion, and ecological imbalances [kg N eq, kg P eq, mol N eq] Photochemical ozone formation: this indicator measures the emissions of pollutants, such as nitrogen oxides which contribute to the formation of ground-level ozone and smog, impacting human health and the environment [kg NMVOC eq] Ozone depletion: Evaluates the release of substances, such as chlorofluorocarbons (CFCs), that deplete the ozone layer in the stratosphere, allowing harmful ultraviolet radiation to reach the Earth's surface [kg CFC11 eq] Santero, N., & Hendry, J. (2016). Harmonization of LCA methodologies for the metal and mining industry, Int. J. Life Cycle Assess.. Hotspot analysis of the process stages in Celsa factory 1 Ladle Hotspot analysis of the process stages in Celsa factory 2 Ladle