Beyond recycled steel: a multi-faceted approach towards sustainable tires

Sustainability in the tire industry is not without challenges, especially when it comes to defining what ‘sustainable’ truly means.

As global awareness of climate change and its effects grows, sustainability has become a key driver for economic activities in various industries around the world. The tire industry is no exception, with many companies setting ambitious sustainability goals and creating roadmaps towards meeting them. Especially in the global West, regulation and national climate ambitions have driven tire manufacturers to accelerate their transition plans. However, sustainability in the tire industry is not without challenges, especially when it comes to defining what ‘sustainable’ truly means.

In recent years, many tire companies have announced their commitment to produce their tires in a sustainable way. However, the definition of what “sustainable” means, varies across companies. One area of consensus is that recycled material is considered part of that sustainable category. By counting the weight of all recyclable or otherwise sustainable materials, and by comparing that to the total weight of the tire, a straightforward sustainability metric can be calculated.

Steel as number one priority for recycling

Of all the raw materials used to produce a tire, steel is the one most suitable for recycling. Steel has been recycled for many decades now, by collecting discarded steel objects to remelt them into new products. Special technologies were developed to melt scrap metal objects and turn them into new raw material feedstock. One well known example is the Electric Arc Furnace (EAF) used to produce steel and other metals.

Since steel reinforcements account for 5-15% of a tire's weight and the scrap content in steel production can be significantly increased, it is obvious that boosting the recycled content of steel is a quick and effective way to raise the percentage of sustainable materials in a tire.

That is exactly why tire companies have turned to their steel reinforcement suppliers to receive – preferably third party certified – declarations of recycled content in the steel. And soon after, requests followed to increase the recycled content far beyond the present levels.

As one of the leading players in the industry, Bekaert witnesses this evolution from the front row. At the Tire Technology Expo in March 2024 for example, customers showed strong interest in Bekaert’s recycled steel certification as the first industry standard for tire reinforcement, and Goodyear displayed a tire comprised of 90% sustainable materials, including the use of Bekaert tire cord with high recycled content (HRC).

The complexity of environmental benefits

At first glance, boosting recycled content in tires seems to have obvious benefits for the environment:

- For every increase in recycled content, there is a proportionate decrease in raw materials to be extracted from the Earth

- The energy intensity of remelting steel scrap to make new steel, is lower than what is needed to produce steel from iron ores, resulting in less carbon emissions

- Every piece of scrap that is recycled, reduces the amount of waste that needs to be treated

However, these apparent advantages must be put into perspective:

- The global demand for steel exceeds the amount of available scrap by far; and this is predicted to remain the case in the future.[1]

- The supply of scrap is not determined by demand, but by the amount that can be salvaged. Steel products used in construction[2], equipment, installations, infrastructure and vehicles, will remain in service for years, if not decades, before they become available for recycling again. There are no surplus stockpiles of steel scrap available.[3]

Increasing the recycled content of a product mainly reallocates scrap between product categories, rather than significantly reducing overall resource extraction. From the above, it must be concluded that the recycled steel in tires should not be the only sustainability indicator. Does recycled steel reduce emissions? Yes. Does recycled steel help the tire industry reach sustainability goals? Yes. But it should not stop there. We believe there are additional pathways leading to sustainable tires.

One pathway is to look beyond recycled and renewable content in the definition of “sustainable” materials. While recycled content reduces the scope 3 upstream emissions in steel tire reinforcement, the bulk of tire emissions is generated during its use phase[4].

Next-generation reinforcement solutions like Mega Tensile could offer sustainability benefits that are complimentary to those of HRC in terms of emissions. Mega Tensile (without HRC) for example, is a complimentary product to HRC, as it allows CO₂ footprint improvements via a different pathway. (Mega Tensile means thinner layers in the tires, leading material savings and less rolling resistance, and therefore less CO2 emissions)

Today, production of these innovative materials does not (yet) allow for HRC. Nonetheless, these solutions should not be dismissed purely for the absence of HRC. Since 100% recycled steel production across all steed applications is not feasible, both solutions may have a valuable role to play. This is why Bekaert continues to push industry boundaries with the ambition to unlock maximum contribution to sustainability.

Another pathway is to explore other options to produce low-CO₂ steel. Low-CO₂ steel can be produced through Smart Carbon Usage, which replaces coal in furnaces with alternate sources and incorporates carbon capture and usage (CCU) or storage (CCS) technologies, potentially making the process carbon-negative. Another approach is Carbon Direct Avoidance (CDA), using renewable energy for electric arc furnaces and Direct Reduced Iron (DRI) to minimize CO₂ emissions, especially by using hydrogen as a reducing agent, which emits water instead of CO₂.

A third pathway to reduce greenhouse gas emissions in the tire industry is by adopting circular business models that extend beyond merely using recycled materials. This approach encompasses enhancing tire durability, promoting re-use through re-treading, and extracting valuable materials from end-of-life tires for new applications. By focusing on these strategies and implementing comprehensive circularity practices, the tire industry can significantly minimize environmental impact and move towards more sustainable production and consumption.

The same pathways apply to other materials used in tire manufacturing, emphasizing the need to reduce emissions in primary material production and adopt circular approaches beyond recycled material usage. Life Cycle Assessment (LCA) offers the essential transparency to evaluate and prioritize these different pathways, and at the heart of it, collaboration across the industry is key to achieving these sustainable practices.

Conclusion

To reach sustainability in the tire industry, there is no ‘one solution that fits all.’ Using recycled steel in tires offers tangible environmental benefits, helps reach sustainability goals and reduces carbon emissions. To achieve true sustainability, the tire industry must explore additional pathways. Combining several approaches can collectively drive the tire industry towards a more sustainable future.

At Bekaert, we work closely together with suppliers, we follow the latest evolutions, and we look forward to expanding our collaborations with industry partners and stakeholders to drive innovation that meets society’s challenges. Let us create a better tomorrow, together.

[1] By 2025, there will be a scrap availability of 0.5 billion metric tons of steel per year, versus 2.2 billion tons of steel demand (23%). The forecast for 2025: ~ 1 billion tons of scrap steel available versus 2.8 billion tons of steel demand (36%). Source: Bloomberg .

[2] In 2022, the building and infrastructure segment utilized 52 percent of the steel produced worldwide. In the same year, the automotive industry accounted for 12 percent of the global steel use, whereas electrical equipment made up three percent of total steel demand. Source: Statista .

[3] Today, around 90% of steel products are recovered at the end of their life and recycled to produce new steel. In theory, all new steel could be made using recycled steel, as its properties remain intact during the recycling process. However, this isn't feasible currently due to a shortage of scrap. Globally, the current production of steel is three times higher than the supplies of scrap available. Source: ING Research .

[4] Use phase accounts for ~87% of a tire’s cradle to grave emissions, while the production stage is responsible for 12%. The tire debris and other end-of-life processes (without considering the benefits of ELT recovery) contribute to 0.69%. Source: Ferrao et. al .