After many twists and turns over the last few years, and following the latest round of consultations and discussions, the European Chemicals Agency (ECHA) has decided to recommend a ban on the use of crumb rubber infill in artificial sports surfaces. This is a massive market for the recycling sector: in Europe, for example, 62% of end-of-life tyres (ELTs) are destined for material recovery, with 527,000 tons processed to make infill for use in sports pitches.
Countless scientific studies over many years have concluded that crumb rubber infill presents no risks to health. However, ECHA’s Committee for Risk Assessment argued that information on the effectiveness of risk management measures was incomplete and that a ban would be more effective in preventing releases to the environment in the long term. During the BIR Tyres & Rubber Committee webinar in June last year, guest speaker Fazilet Cinaralp of the European Tyre and Rubber Manufacturers’ Association (ETRMA) warned that the repercussions of such a ban could well prove “catastrophic” for the crumb rubber sector and for tyre recycling in general.
The ban would be scheduled to take effect after a transition period of six years, leaving very little time for producers to find new outlets for their crumb rubber. At present, there are no material recycling alternatives for the potentially huge surplus of ELT-derived rubber infill materials, with energy recovery the only possible outlet that could attempt to absorb such large volumes. Indeed, the recommendation from ECHA is likely to provide a boost to tyre-derived fuel and pyrolysis operations, with the major oversupply of material almost certainly leading to a substantial increase in gate fees.
Against this backdrop, and with seemingly perfect timing, our Committee’s webinar in October 2020 brought first-hand confirmation that the world’s largest tyre manufacturer – Michelin – was spearheading the breakthrough BlackCycle project aimed at recycling almost 50% of Europe’s ELTs into new tyres within five or six years. Research Programme Manager Michaël Cogne explained that the initiative was pooling the talents of seven industrial partners, five research and technological organizations, and an innovation cluster, with their specialisms spanning tyre collection, granulation, pyrolysis, transformation of pyrolytic oil into more valuable materials, carbon black manufacture, life-cycle analysis, environmental assessment along the value chain, data management and communications.
The magnitude of the BlackCycle initiative and its potential as a game-changer for the used tyre market cannot be overstated. Among all industrial sectors, it is the only project of this scale designed to complete the virtuous circle when recycling end-of-life products. If BlackCycle is successful in meeting its objectives, crumb rubber manufacturers will have a substantial and reliable alternative outlet for their product; in all likelihood, they would become suppliers of feedstock either to Michelin or to similar projects which other tyre manufacturers may have in the pipeline.
Industry-led innovation is not the only route to creating a more sustainable tyre sector; policy-makers and politicians can also play a major role, such as through the introduction of mandatory recycled content quotas in new rubber compounds so long as these do not entail a significant impact on product properties.
A review of developments in 2020 would be incomplete without mention of the profound impact of the COVID pandemic. With fewer cars and trucks on the road throughout the crisis, this naturally led to a decline in the number of ELTs generated and to a decrease in the volumes recycled last year. Other key effects included an undersupply of some grades, such as rubber powder, while exportation of low-value-added ELT-derived materials became less attractive owing to unprecedented freight increases.
And of course, many COVID-related challenges have carried over into 2021.
The most important use of rubber is in vehicle tyres; over 70% of all the world’s rubber ends up wrapped around the wheels of cars, bicycles and trucks. Other applications are industrial rubber goods used in, for example, construction, aircraft, footwear and gloves.
With over a billion cars and commercial vehicles already in use worldwide, end-of-life tyres (ELTs) are among the largest sources of waste today. Tyres made of approximately 80% rubber compound, steel and textiles are built to last, which in turn makes them a very challenging product to recycle.
Historically, the difficulty in recycling has led to uncontrolled or illegal scrap tyre disposal, but with the formation of national ELT management companies such as Aliapur and Signus, and also the development of new end markets for tyre-derived materials, ELTs are increasingly diverted from landfills as the tyre recycling industry continues to grow.
In 2018, over 3 million tonnes of ELTs were recovered in Europe, representing a treatment rate above 96%. Taken together, Europe, the USA and Japan have an average recovery rate of 90%.
There are several ways in which tyres can be reused or recycled. There are important differences in laws and regulations worldwide aimed at encouraging or discouraging different methods.
The two main recycling routes are material recovery and energy recovery, and their share of ELT treatment varies from country to country. For example, the split between material recycling and energy recovery in Europe is around 50/50 whereas energy recovery accounts for a higher proportion in the USA.
For both tyres and non-tyre rubber scrap, the material recovery technologies are usually the same.
In Europe, almost half of the tyres collected are used to replace coal in coal-fired power stations and in cement furnaces. Other industries, such as steel manufacturers, also use scrap tyres as a fuel in place of fossil fuels. When these industries choose ELTs over coal, they can limit their CO2 emissions by up to 30%. Compared to coal, ELTs are on average 80% cheaper while having 110% of its heat value.
Halfway between material and energy recovery lies tyre pyrolysis, a technique that heats whole or shredded tyres in a reactor vessel containing an oxygen-free atmosphere in order to extract fuel and other components.
Shredded tyres/rubber (+/- up to 200 mm)
In civil engineering works, shredded tyres can be used as a filler to stabilize weak soil and also as insulation for roads, bridge abutments, etc.
Granulated tyres/rubber (+/- up to 20 mm)
One of the major outlets for ELTs and other rubber scrap is in granule form for artificial turf and playgrounds.
Pulverized tyres/rubber (+/- up to 2 mm)
Coarser rubber powder is used in asphalt applications to improve road performance, reduce noise levels and lower maintenance costs.
Finer rubber powder (micronized) can be incorporated at low levels as a filler in virgin rubber compounds and can be further processed into reclaimed/regenerated rubber, which is currently the only way to use ELTs and other rubber scrap in line with the circular economy model.
In 2018, over 3 million tonnes of ELTs were recovered in Europe, representing a treatment rate above 96%.
Taken together, Europe, the USA and Japan have an average ELT recovery rate of 90%.
ELTs used as fuel are on average 80% cheaper than coal while having 110% of its heat value.