Does green aluminium really exist?

Implementation of fields of action for green aluminium

For aluminium production to comply with the EU Taxonomy’s requirements for green products, it is important to consider both the input side and the process side.

The input side:

As described in a past issue of AluReport [8], the aluminium market is growing at a rate of approx. 3-4 % per year, with this trend showing no signs of slowing. Due to high durability of aluminium products and the growth rate at the moment, relatively little aluminium scrap comes back for recycling. This means that primary metal is still used to cover more than two-thirds of the demand for aluminium products. Thus it is only possible to cover around one-third of demand through recycling [9].This makes it all the more important to recycle the material as efficiently as possible. In addition to efficient processes, this also means making the best possible use of collected scrap. Aluminium products are made from many different alloys with different alloying elements that determine their properties. Combining these various alloys creates a mixture that does not correspond to any individual alloy family. With this in mind, producing a high-quality alloy exclusively using mixed scrap recovered from waste presents a considerable technical challenge. The options are therefore to produce an alloy that meets more lenient requirements (downgrading), increase the purity of the scrap by adding primary aluminium, or carefully sort the scrap mixture and precisely configure the microstructure of the output metal. When it comes to increasing the proportion of recycled material and manufacturing larger volumes, coordinating with customers is paramount. Without changing the tolerances for existing alloys, the volume of usable scrap will not even cover a third of demand in most cases.

The process side:

AMAG production facilities were designed and are operated to meet or even surpass the current state-of-the-art technology, comply with all legal requirements, and minimize their environmental impacts as far as possible. Minimizing environmental impacts includes making sure the company uses materials, auxiliary and operating materials, water and energy as efficiently as possible. It is also vital that we continuously optimize our production processes and invest in state-of-the-art machinery. AMAG therefore takes a comprehensive view of all environment impacts and efforts to minimize them. This includes measuring emissions released into the air, ground and water. These figures are subject to strict, regular monitoring. For example, AMAG continuously monitors the composition of exhaust gas from the smelting furnace by examining dust particle levels and organic carbon compounds. The measurement devices are subject to minimum availability periods that must be fully documented. Device availability figures and measurement results are documented in annual reports and transmitted to the authorities.Similar statutory requirements apply for emissions into the ground and water. Cooling water for the production is circulated. Thanks to improvements, AMAG has kept its water consumption and industrial water abstraction levels constant over the years while increasing its production capacities. Furthermore are reused excavated material and rubble from construction sites within the company. AMAG also works hard to implement the sixth aspect of the EU Taxonomy: biodiversity.These efforts include managing the company’s forest (180 ha), focusing on native woods with high tolerance of climate stresses, with support from the University of Natural Resources and Life Sciences (BOKU) in Vienna. In addition, the company’s initiative to breed Varroa-resistant bees in partnership with "Bienenzuchtgruppe Oberösterreich-Salzburg" has already achieved initial successes.

Even greener aluminium?

There are calls from lawmakers and customers (the latter often spurred on by the former) to make aluminium even greener, further reducing its negative impacts on the environment. While AMAG is happy to comply with this request, it is important to ensure this is a shared endeavor. In November 2023, AMAG started its first large-scale test to smelt aluminium on an industrial scale using hydrogen as the only fuel source. Preparations for the test have been underway for over a year. The official approval process will have to be expedited before conversion of the company’s smelting activities.Public authorities will also have to guarantee provision of the necessary infrastructure and swiftly prepare connections for green electricity and pipelines for green hydrogen. It is also crucial for these resources to be supplied in sufficient volumes and at competitive prices. Companies should work with their customers to establish long-term, closed-loop relationships so that scrap can be recycled into new products with no loss of quality, with established alloy tolerances revised to facilitate increased use of mixed scrap. AMAG’s leading expertise in aluminium recycling will become even more important for the production of green aluminum. Continuing to produce high volumes of aluminium will require AMAG to coordinate closely with its customers.Producing secondary aluminium only requires 5 % to 10 % of the energy used in primary aluminium production and thereby represents the most significant contribution to creating a climate-neutral product and a climate-neutral industrial site. However, if we are to fully exploit this potential, we will also have to achieve corresponding innovations in relation to alloys, with wider tolerance ranges for alloying elements to increase the scrap utilization rate, or novel alloy concepts such as AMAG CrossAlloys®.