For most people, the term ‘vehicle emissions’ conjures up images of gridlocked cities rendered smoggy by tailpipe emissions. OEMs and suppliers alike have scrambled to bolster the visibility of their clean vehicle portfolios in recent years, in preparation for stringent new greenhouse gas (GHG) emission targets taking effect in 2021 and 2025 for Europe and the US respectively.
Few would argue that tailpipe exhaust is responsible for a sizeable portion of global carbon emissions. The European Commission, for example, estimates that cars are responsible for some 12% of total EU CO2 emissions. The EU aims to drive fleet average emissions below 95 grams per kilometre – a 40% reduction compared with the 2007 average of 158.7 grams per kilometre.
With battery prices dropping, performance improving and customer acceptance rising, it seems little can stop more electric vehicles (EVs) reaching the road to play their part in hitting these targets. But this excessive focus on the tailpipe could prove misguided. That’s according to Jonas Adolfsson, Business Development Automotive at SSAB. The advanced high strength steel (AHSS) manufacturer is a part of WorldAutoSteel (WAS), a group of 22 manufacturers that promotes the global steel industry’s capability to meet the automotive industry’s needs sustainably and responsibly. Tailpipe emissions count for only a portion of vehicle emissions overall, they argue, and CO2-per-mile-based targets were originally conceived to achieve reductions in oil consumption, not necessarily to curb GHG emissions.
We welcome the increased attention to end-of-live aspects on vehicle design, where high strength steel can not only help reduce the amount of material used in a vehicle, but can also be fully recycled
In order to tackle GHG emissions effectively, the group advocates lifecycle assessments (LCA) for vehicles. These take into account emissions from across the car’s lifetime, from raw material extraction to the product’s end of life. Using these benchmarks, they say, steel could outperform lightweight alternatives as a greener choice.
Aluminium, for example, is a popular choice among EV manufacturers, to help cope with heavy battery weights, but with penetration increasing, environmental problems already widely discussed within industry circles today will be brought to the attention of the general public.
One is the energy intensity involved in manufacturing. Using the University of California Santa Barbara Automotive Energy & GHG model, WAS argues that an EV made from 100% AHSS uses some 36,000 megajoules less energy over its lifetime than one made from 100% aluminium. The complex procedure for aluminium extraction and refining, they say, means that aluminium production uses eight times more energy per kilo than AHSS.
The mix of materials in automotive applications will increase, and steel can be easily separated from other industrial and domestic waste products by magnetic techniques, so steel will prove a good solution for a dismantler. In addition, steel recycling infrastructures are already well established throughout the world
Another is material recycling. Whilst aluminium recycling is fully possible, says Adolfson, from an LCA point of view, things might not add up. “To recycle aluminium, you have to be careful to separate different grades,” he explains. “For example, if you put a piece of 7000-alloyed aluminium in a basket for a 6000-alloyed sheet, it destroys the whole melt. Steel does not have this restriction.” In this regard, aluminium recycling is therefore a more complex task in which it is easier to make costly mistakes.
Another potential material of choice for lightweighting purposes is carbon fibre reinforced plastic (CFRP) – with costs decreasing, the high-strength, low-weight polymer may not be the preserve of the supercar segment forever. But from a sustainability and cost point of view, says Adolfsson, the future isn’t great, arguing that a lifecycle assessment (LCA) of a vehicle featuring CFRP could mean an increase in GHG emissions.
New lease on life
By contrast, says Adolfsson, AHSS is fully recyclable. As he points out, almost half of the world’s current steel production is made using recycled steel. “The mix of materials in automotive applications will increase in the near future,” he says, “and steel can be easily separated from other industrial and domestic waste products by magnetic techniques, so steel will prove a good solution for a dismantler. In addition, steel recycling infrastructures are already well established throughout the world.”
There are no considerations for OEMs when it comes to the quality or performance of recycled AHSS. Metallic bonds are restored upon solidification, and continually recover their original performance properties, even after multiple loops
For manufacturers, he says, recycled AHSS presents a win-win situation, lowering carbon footprint whilst also removing material from the car, meaning lightweighting benefits. “There are no considerations for OEMs when it comes to the quality or performance of recycled AHSS,” he says. “Metallic bonds are restored upon solidification, and continually recover their original performance properties, even after multiple loops. At the end of its useful life, a steel product can be converted back into new and better steels, often for use in more demanding applications.”
SSAB itself is already using around 20% recycled product in its automotive applications. Moving forward, the company has even greater ambitions – by 2025, it hopes that customers can save a combined 10 million tonnes in CO2 emissions through further development of the steel. Beyond that, the company itself is hoping to perfect a ‘fossil free’ steelmaking process by 2045.
The European Commission estimates that every year, some seven to eight million tonnes of waste are generated in the region by end-of-life vehicles. 2015 targets for the European End of Life Vehicle Directive called for at least 95% recovery and re-use of vehicles. This, coupled with rising material prices, have made scrap vehicles an increasingly valuable commodity.
At the end of its useful life, a steel product can be converted back into new and better steels, often for use in more demanding applications
Now tasked with extended responsibility, these developments have made the challenge for OEMs to build easily recycled vehicles all the more important, regardless of the material used. This includes the aluminium industry, which also believes it is on course for a more sustainable future. In October 2017, Novelis claimed that some 55% of materials used in the aluminium making process were recycled. The body of America’s best-selling car, the Ford F-150, has been largely built from aluminium since the launch of the 2015 model. According to Novelis, the company collected enough scrap metal over the 2017 period to produce 30,000 F-150 bodies per month.
A further 50,000 tones of scrap collected equates to 200,000 Jaguar XE body shells. In September 2017, JLR announced its REALITY project had developed new closed-loop aluminium production techniques, allowing for further use of recycled materials in cars. Aluminium recycling, the manufacturer announced, used up to 95% less energy than primary aluminium production.
In the meantime, SSAB will continue its efforts in the AHSS sector, and believes that a sharpened focus from across the materials industry can only be a good thing. “We welcome the increased attention to end-of-life aspects on vehicle design,” says Adolfsson, “where high strength steel can not only help reduce the amount of material used in a vehicle, but can also be fully recycled.” Now more than ever, says SSAB, companies need to discard linear business models and embrace a zero-waste circular model, in which resource efficiency, repairing, recycling and upgrading are emphasised. With these activities in mind, says the company, steel is the far more manageable option.
This article appeared in the Q4 2017 issue of Automotive Megatrends Magazine. Follow this link to download the full issue