Environment & Sustainability
Making light work of
Aluminium is playing a key role in combatting electric cars’ weight problem, which makes recycling the material all the more important. James Bakewell looks at the challenges and opportunities
The automotive industry's appetite for lightweight, strong aluminium shows few signs of being sated. A recent report from analyst firm DuckerFrontier (commissioned by trade body European Aluminium) estimates that, on average, a car produced in Europe in 2019 contained nearly 180kg of aluminium – a 20% increase on 2016.
As the automotive industry rapidly electrifies, it seems that this trend is set to continue. DuckerFrontier notes that in order to compensate for the weight of the heavy battery and thereby increase their range, electric and plug-in hybrid vehicles tend to feature significantly more aluminium than their conventionally powered counterparts. The study forecasts that almost 200kg of the metal will be used per vehicle by 2025.
In addition to its weight saving potential, aluminium is highly recyclable. Indeed, the Aluminium Association reports that approximately 75% of the aluminium ever produced in the EU and the USA is still in use today. Further, the production of aluminium from recycled materials consumes only 5% of the energy needed to produce primary aluminium with the same properties, significantly reducing the cost and environmental impact of using the material.
This attribute is of vital importance to carmakers from business, regulatory and public relations perspectives. Aluminium is significantly more expensive than steel and recycling brings this cost down. EU directives, meanwhile, stipulate that by weight, 85% of end-of-life vehicles must be reused or recycled, with a total material recovery rate of 95%.
It’s not just governments that are forcing the industry to reduce the environmental impact of its operations, either. Pressure is growing from consumers and charities as well. A recent report from Greenpeace accused the industry of "driving the climate crisis" and cites figures from Volkswagen, which estimates that, on average, 6.5t of carbon dioxide equivalent (CO2) is emitted during the production of one of its cars – 15% of the emissions it will create over its lifetime.
Closing the loop
These factors have driven many carmakers to develop so-called “closed-loop” systems for the recycling and re-use of their aluminium production scrap. Jaguar Land Rover (JLR) has made significant progress in this area. Through the REALCAR project, the carmaker has started working with aluminium supplier Novelis, Zyomax, Norton Aluminium, Stadco, Brunel University and Innoval Technology. Together, the partners have developed a high-strength aluminium alloy (RC5754) that could be produced using scrap material sourced from the OEM’s press shops. This alloy, which contains up to 50%-by-weight scrap, was first used in the body structure of the Jaguar XE, launched in 2015.
In the first year of production, the carmaker claimed to have recycled 50,000 tonnes of aluminium scrap through the programme, preventing 500,000 tonnes of greenhouse gas emissions. Between September 2013 and March 2020, it used around 360,000 tonnes of closed-loop scrap to manufacture aluminium parts for all of its vehicles.
Numerous carmakers are now implementing similar programmes to the one rolled out by JLR. In the last twelve months alone, Audi announced that it has introduced a closed-loop system at its plant in Győr, Hungary, which consumes approximately 38,000 tonnes of aluminium each year. BMW, meanwhile, revealed that it had invested some €6.5m ($7.7m) in order to recycle waste sheet materials generated at its press shop in Dingolfing, Germany. The manufacturer estimates that by recycling this waste, it can reduce its CO2 emissions by around 120,000 tonnes a year. Finally, in 2019, Novelis revealed that it had set-up a closed-loop recycling system with Volvo Cars. It says that this system reduces the size of the CO2 footprint associated with the aluminium sheet delivered to the carmaker by 78%.
Facing the reality of recycling end-of-life vehicles
While closed-loop processes for the recycling of aluminium production scrap are now reasonably well established, the development of commercially viable processes for the recycling of aluminium from end-of-life vehicles represents a different, and significant, challenge. Put simply, it is difficult and expensive to separate various alloys from one another once a car has been shredded into pieces. Through the REALITY project, JLR is now working with Axion Recycling, Innovate UK, Novelis, Norton Aluminium, Brunel University London, WMG University of Warwick and Innoval Technology to develop a process that solves this problem.
The process has been tested on pre-production Jaguar I-Pace prototypes that first had their batteries safely removed. Scrap from the vehicles was sorted using sensor technology supplied by Axion Recycling. Once separated, the aluminium scrap could be melted and mixed with recycled aluminium from other sources to form a new prototype alloy. Now, the carmaker has analysed the recycling and manufacturing processes developed through the project and claims that, when compared with those used for the production of the automotive-grade alloys it currently uses, they have the potential to reduce the amount of CO2 generated by up to 26%.
The project lead for REALITY at JLR, Gaëlle Guillaume, says that ultimately, as vehicles become increasingly automated, connected, electric and shared, JLR will be able to plan for the retirement of large fleets, which will enable it to engineer such closed-loop recycling processes into tight production schedules, as the vehicles can be recovered and shredded en masse.
Indeed, the electrification of the automotive industry is presenting new opportunities for the recycling of aluminium. A typical battery pack for an EV, for instance, may contain 70-100kg of the lightweight metal. Looking to capitalise, aluminium supplier Hydro and Swedish battery manufacturer Northvolt have this year formed a joint venture – Hydro Volt – for the recycling of battery materials and aluminium from EVs.
Through Hydro Volt, the companies plan to build a pilot recycling plant in Norway with the capacity to process more than 8,000 tonnes of batteries per year. This plant is set to go live in 2021 and will be followed by the construction of a full-scale plant at Northvolt’s Ett facility in Sweden in 2022.
The executive vice president for energy and corporate development at Hydro, Arvid Moss, concludes: “We are excited about the opportunities this represents. Hydro Volt can handle aluminium from end-of-life batteries as part of our total metal value chain, contribute to the circular economy and at the same time lessen the climate footprint from the metal we supply.”