Project nominated for Excellence in Low-carbon steel production Steelie Award 2022
In February 2021, Tenaris set a medium-term target to reduce the carbon emissions intensity of its operations by 30% by the year 2030, compared to a 2018 baseline, considering Scopes 1, 2 and 3 emissions.
Tenaris aims to achieve this target by using a higher proportion of recycled steel scrap in the metallic mix and by making investments to increase energy efficiency and renewable energy while also looking to implement hydrogen and carbon capture storage and use.
This medium-term target forms part of a broader objective of decarbonising operations and reaching carbon neutrality.
Over the past year, Tenaris has made good progress towards its mid-term objective, reducing 14% of CO2 emissions vs baseline by focusing on energy efficiency and reducing the proportion of pig iron charged into the electric furnaces.
This was mainly implemented in its largest steel and pipe-producing mill based in Veracruz, Mexico, TenarisTamsa, where a reduction of 20% in CO2 emissions during 2021 vs the 2018 base year was achieved.
The company’s EAF web-based model is fed with thermodynamic data (i.e. enthalpy of reactions, the specific heat of steel and fluxes, etc.) and other operational parameters of each furnace (size, arc voltage, etc.) to calculate the metallic yield, electrical energy and oxygen demand, electrode consumption, and expected CO2 emissions.
This model is integrated with a data-driven simulation tool called the scrap recipe optimisation simulator, which based on statistical information collected from previous heats, identifies the best combination of scrap types to achieve a low content of residuals elements (Cu, Ni, Sn, Sb) in the final product while minimising the cost of the metallic charge.
These aspects are of paramount importance for the local conditions of TenarisTamsa, as clean scrap with low levels of residual elements (like Cu) is scarce.
As a result of the implementation of these predictive tools, TenarisTamsa reduced pig iron charged during 2020 and 2021 by 50%, resulting in a 20% reduction of CO2 emissions in the steel process, and with only a 3% increase in electricity and a minimal impact on process yield without compromising steel quality and process costs.
The model includes the cost of all raw materials and consumables, together with the internal price defined by Tenaris for CO2 emissions (80 USD/tonne), allowing them to internalise the cost of associated emissions on the production of steel.