CLOSING THE LOOP ON AUTOMOTIVE ALUMINUM SCRAP TO MINIMIZE CARBON EMISSIONS

(extracted from Alumobility's white paper of the same name, available here.)

Closed-loop recycling is a potent solution to lower CO2 in automotive aluminum sheet

The world needs more aluminum. Thanks to its light weight and infinite recyclability, aluminum is a key driver of our transition to a circular economy, and the second-most used metal by mass in the automotive sector. Its numerous attributes that contribute to vehicle efficiency, performance, safety, and sustainability mean that it will play an increasingly important role in the auto industry, especially with the shift to electric vehicles. It is expected that from now until 2050, the market for aluminum will expand by over 50%.[1]

To meet this growing demand while mitigating climate change will require both primary and recycled aluminum. Smelting operations are working to decarbonize the power supply when producing primary metal. Nonetheless, this decarbonization will take time, whereas low-carbon aluminum from recycling is available immediately. To minimize global warming, it is crucial to maximize recycling without delay.

Aluminum can be recycled indefinitely at a low melting point, so recycling uses ~5% of the energy it takes to produce primary aluminum, reducing carbon emissions by as much as 95%.[2] Aluminum produced via the recycling process results in greenhouse gas emissions of 0.5 metric tons for each metric ton of metal, compared with a range of four to 20 metric tons for primary aluminum production.[3] In short, recycled aluminum is the low-hanging fruit for decarbonizing automotive manufacturing now.

CLOSED-LOOP RECYCLING IS KEY

However, not all recycling is the same—true circularity requires a closed-loop model.

Aluminum is rarely used in its pure form; normally it is alloyed with other elements to attain the desired properties. Wrought alloys used for rolled sheet or extruded profiles contain smaller quantities of alloying elements than casting alloys. While wrought alloys can be recycled into casting alloys, the process is generally too inefficient to make sense the other way around. 

Recycling within the same alloy family is key to achieving circularity. For example, if wrought aluminum scrap from a car door manufacturing process is sorted, sent back to a rolling mill, and recycled in a closed-loop process, it can be manufactured as brand-new material for car doors. On the other hand, if different alloy families are mixed together, the resulting metal is difficult to reuse for its original purpose, often requiring the addition of large quantities of primary aluminum. In the worst case, it can no longer be used to manufacture a wrought material (e.g., to produce a door), but will serve as a casting alloy or in another value stream. This is a serious missed opportunity for circularity, with a loss in CO2 savings.

Automotive press shops are able to effectively use as much as 60% of the aluminum they receive from sheet suppliers, with a scrap rate of around 40% or more. This scrap sheet metal provides a huge opportunity to increase sustainability in the supply chain. And yet, in the automotive sector, much aluminum scrap recycling is open-loop, with the material turned into cast aluminum. Today, global demand for recycled cast aluminum meets supply, notably for internal combustion engines. But as our markets transition to electric vehicles, with their smaller motors, the demand will shift to wrought metal.

JOINT ACTION TO REDUCE CO2

Alumobility supports joint action throughout the value chain to maximize the collection and sorting of aluminum scrap, and to increase recycling rates and efficiency.[4] OEMs and stamping suppliers can work together with producers of aluminum alloys, by:

• improving scrap collection and sorting to limit the mixing of alloys,

• and closing the loop by sending scrap back to the rolling mills rather than turning it into casting alloys or selling it to scrap dealers.

Introducing as much recycled aluminum sheet as possible is fundamental to decreasing the industry’s emissions and meeting decarbonization targets. At the same time, it responds to growing consumer demands for the automotive industry to engage in more sustainable practices and accelerate our journey to a low-carbon future.  

END-OF-LIFE IS ALSO REBIRTH

While recycling aluminum scrap offers an immediate solution to reducing emissions today, recycling end-of-life metal is an opportunity for tomorrow. Aluminum material in products, such as cars, that reach their end of life represents a major source of scrap that can be reintroduced into the circular economy. Currently, very little end-of-life material is sent back to the rolling aluminum industry for recycling and reuse. OEMs can support a more circular business model by designing vehicles for recycling and disassembly. Designing components in a single alloy family makes them easier to sort. Improvements in dismantling flows help ensure that end-of-life material is sent back to rolling mills. The best way to take advantage of this future opportunity is by starting to tackle it right away.

[1] https://www.european-aluminium.eu/vision-2050/

[2] https://www.aluminum.org/sites/default/files/2022-01/2022_Semi-Fab_LCA_Report.pdf

[3] Source: Coal based production and global average: Life cycle inventory data and environmental metrics for the primary aluminium industry, World Aluminium, 2015. Addendum, August 2018. Other: Environmental Profile Report 2018, European Aluminium

[4] This paper reflects Alumobility’s position. It does not involve any coordination of the individual recycling strategies of its members.

Download the complete white paper here.

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