To build a more sustainable future, we need to improve what we make, how it is made, how we use it, and how it is reused or recycled in the future. That’s is why ArcelorMittal uses life cycle assessment (LCA) to benchmark our production processes and measure how our products and solutions are becoming more efficient and sustainable.

LCA critical to understanding full impact of mobility

LCA is a very powerful tool for the transportation sector. If you look at the entire lifecycle of a vehicle, steel is already the most sustainable material to make efficient and affordable cars. That’s partly thanks to the fact that steel already has much lower CO₂ emissions in primary production than competing materials. In the use phase, the most advanced steels perform even better than other materials, particularly when it comes to passenger safety.

And in the end-of-life phase, steel outperforms any other material due to the ease with which it can be recovered and recycled. That’s why steel is the most recycled material in the world. “Unlike materials such as aluminium and plastics, steel is very easy to extract from waste streams with a magnet,” says Julio L. Rivera, automotive LCA specialist for ArcelorMittal Global R&D. “End-of-life aluminium accumulates many alloying elements which cannot be easily removed from the metal once it is re-melted in the recycling process. This problem is much less of an issue for steel. With steel, the alloying elements present in the recycling stage are much easier to remove with industrial purifying techniques.”

Encouraging innovation at all stages

Adopting an LCA approach to assess the environmental advantages of different materials highlights these benefits. LCA considers the entire life cycle of the product or service, from cradle to grave. It also considers a wide range of environmental impacts, from the local to the global level. And it encourages innovation in all parts of the vehicle and all phases of its life – from raw material selection to end-of-life recycling. By incorporating lifecycle thinking in the innovation process, we can reduce carbon emissions and take a big step on the journey to create a sustainable future.

ArcelorMittal has been a pioneer in using LCA to assess the true environmental impact of our products since the early 2000s. Our first formal LCA project took place in 2006 when we carried out a study to assess the impact of our automotive products. That approach continues today. LCA is an integral part of every S-in motion^® study ArcelorMittal carries out.

“The results of these LCA studies inform our clients about the environmental performance of steel,” says Julio L. Rivera. “When compared with cradle-to-grave LCAs for other materials, it enables OEMs to select the most environmentally friendly solution for their application.”

Despite LCA being an ISO standard, and widely used by industry, there is no link between LCA and current regulatory policy. Instead, the main automotive emissions considered are tailpipe emissions. As a result, the lighter car ‘wins’ because the use phase is the only part of the vehicle’s life which is considered.

However, when the full life cycle of the vehicle is taken into account, the story is very different. Lightweight materials, though lighter, require more energy to produce per kilogram.

To provide a neutral basis for material selection, LCA should be used. This is why ArcelorMittal favours regulations which are LCA-based.

In late 2018, the European Parliament recognised the importance of life cycle thinking when assessing emissions beyond 2020. That will require carmakers to report the lifecycle emissions of new cars from 2025. This change has been welcomed by ArcelorMittal and other steelmakers as it levels the playing field for all materials. ArcelorMittal hopes that these measures will be emulated by regulators across the world.

LCA even more important for electric vehicles

Using LCA to assess the true impact of mobility is critically important when it comes to battery electric vehicles (BEVs). Existing legislation in many parts of the world focuses on ‘tailpipe emissions’ during the use phase of the vehicle’s life. But with electric vehicles (EVs), there are no tailpipe emissions. However, the technology and fuel used to generate the electricity an EV uses can have a dramatic impact on emissions in the use phase. These indirect emissions are ignored by current regulations.

“How the electricity used by BEVs is produced is another factor that must be considered,” notes Julio L. Rivera. “With an internal combustion engine (ICE) vehicle, the amount of fuel it will use over its life can be estimated and remains fairly constant during the years it is used. The environmental impact of that fuel can also be considered constant over the vehicle’s life. But with EVs, OEMs need to factor in the impact of electricity production methods now, and in 10 to 20 years. Today, the electricity used by the vehicle may have a similar environmental impact as ICE fuels. However, the impact may be lower in the use phase as more renewable sources of energy are added to the grid mix. This is expected to significantly lower the total accumulated carbon dioxide emissions of the vehicle over its lifespan.”

While the total life cycle emissions of BEVs are expected to decrease compared to ICE vehicles, the metal production and end-of-life impacts will become more relevant. This is a one of the drivers behind ArcelorMittal’s efforts to develop low-carbon steelmaking technologies.

Existing LCA studies have focussed on internal combustion engine (ICE) vehicles which have been adapted to include batteries and an electric powertrain. During 2019, ArcelorMittal will release its first S-in motion^® study into a BEV designed from scratch. In this study, the material choices are optimised to meet the expected performance of the BEV with respect to battery protection, passenger safety, and including the vehicle’s production and end-of-life phases.

The results of the S-in motion^® BEV study demonstrate why steel is expected to remain the dominant auto body metal as the electrified vehicle market grows. This is because innovations in battery technology will allow OEMs to achieve their lightweighting and driving range goals more cost-effectively with steel. Lightweighting with materials such as aluminium will become a less attractive option.

Low-carbon mobility with steel

The environmental footprint of steel is relatively low compared to other materials, but cars require a lot of steel. Typically, 60 to 70 percent of a vehicle is made of steel. For that reason, automakers are pressing steelmakers such as ArcelorMittal to decarbonize the steelmaking process. This is also required if the industry wants to meet climate change goals such as the Paris Agreement.

That’s why we are undertaking extensive research and pilot programs within our operations with the goal of reaching carbon neutrality by 2050. In May 2019, we published our first Climate Action Report where we describe our progress to date. The Report also provides an overview of potential ‘breakthrough’ technological solutions to decarbonize steel. We are finalising our strategic roadmap and will provide an interim target for 2030 in 2020.

With low-carbon steelmaking and mobility solutions which utilise clean energy sources, it’s possible to envision a future where mobility becomes a carbon-neutral industry. Something that was hardly imaginable just twenty years ago when ArcelorMittal started its LCA journey!