Tyres & Rubber
2019 marked a turning point for the tyre and rubber recycling industry. Having been under great threat for the past few years, it looked last summer like the European Commission was about to announce the end of tyre granulate infill, currently the major outlet for end- of-life tyre (ELT) recyclers. Contrary to expectations, however, EU’s executive spokesperson Natasha Bertaud confirmed last July that “no such proposal is under preparation from the Commission”, thus refuting media reports that the Commission was planning to ban artificial turfs. A similar decision was announced shortly afterwards by the US Environmental Protection Agency.
Nevertheless, the last two or three years have seen an explosion in negative publicity within Europe and America surrounding the use of ELT-derived rubber granulate, leading to a considerable drop in demand for such material. States and municipalities in the USA and Europe have continued to propose bans or other sanctions on the incorporation of crumb rubber in playgrounds and sports pitches despite over 100 separate studies reaching the conclusion that its use in these applications carries no proven risk to humans or to the environment.
Therefore, it is more essential than ever before that other applications for ELTs are considered, developed or expanded.
In the past two years, national and European waste policies have begun to shift away from the linear model of “take, make, use and dispose” to a more circular approach whereby the value of resources is maintained for as long as possible. A mandatory minimum recycled content of over 25% has been adopted for certain plastics, giving an unprecedented boost within Europe to the markets for recycled plastics. It is clear that Europe’s market for recycled rubber will never improve unless regulators make a decisive move and impose minimum recycled contents for new products.
Ten years ago, professional bottlers would have said it was not only impossible but also dangerous to incorporate recycled PET in beverage bottles. Now, with the help of the legislator, major water and soda bottlers incorporate 25%, 50% and, in some cases, 100% rPET in their manufacturing processes. Without the help of the legislator, it is too hard to shake preconceived ideas, conventional wisdom and powerful industrial lobbies.
Fifteen years ago, rubber regeneration was limited to often- polluting and high-energy-consuming thermochemical processes. In the past decade, breakthroughs have been made – especially in China – with non-polluting processes that have doubled the mechanical properties of the regenerated compounds; we are getting closer and closer to real devulcanization and, with current technologies, it is possible to incorporate around 10% regenerated rubber in a new tyre without really affecting its properties. The proportion can be as high as 70% for technical parts in a closed-loop system.
Rubber is definitely more complicated to regenerate than plastics or metals – but without the help of the legislator, tyre and rubber recycling will remain the “poor relation” of the recycling industry.
In Europe and the USA, tyre scrap is generally treated as a low-value- added material which is turned into either energy or used as a filler for turf infill, mixed with asphalt or used to make cheap furniture, etc. Less than 1% in Europe is regenerated into reclaimed rubber. In China, by contrast, more than 95% of ELTs are turned into high-value-added reclaimed rubber; the rate is similar in India and demand for reclaimed rubber is greater than supply, thus forcing many major players to import European tyre scrap which is generally considered of higher quality than local material.
In a world where exports of all types of scrap are being restricted, it is important to start giving consideration to adding value to rubber scrap in its country of origin and exporting it only after reprocessing. This is already the trend for plastics and metals, and it should be followed by rubber too.
Europe has one of the best feedstocks in the world for making regenerated rubber; the European Parliament should step in – just as it did for plastics – in order to change mindsets and force European rubber industries to incorporate a minimum recycled content in their production so long as the properties of their end products are not greatly affected.
We believe mandatory recycled contents of 5-10% for tyres and 10- 20% for technical rubber parts are definitely workable.
“Without the help of the legislator, tyre and rubber recycling will remain the ‘poor relation’ of the recycling industry.”
Max Craipeau
IMPORTANT FACTS
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%.
MATERIAL RECOVERY
For both tyres and non-tyre rubber scrap, the material recovery technologies are usually the same.
Sorting: As with all other waste streams, it is important to segregate scrap according to type and to process separately to ensure the highest quality output.
Retreading: During the sorting process, tyres which still have quality casings are sent to retreaders where they are given a second life (and sometimes more) by replacing the worn tread with a new one.
Shredding: Tyres whose casings are damaged are usually sent to a shredder for size-reduction. ELT shredders are usually smaller than those used to process end-of-life vehicles but, nevertheless, they have to be extremely robust to handle such durable materials. By downsizing tyres and other rubber scraps, many recycling opportunities are opened up.
Metal separation: Rubber scrap, especially ELTs, are commonly embedded with metal and require ferrous or non-ferrous separation using magnets and/or eddy-current technologies.
Granulation: Granulators are widely used in the rubber recycling industry to further reduce the dimensions of the shredded tyres after metal separation and to produce quality rubber granules.
Pulverization: For more technical uses, rubber granules can be pulverized at ambient or cryogenic temperatures in order to produce micronized rubber powder.
APPLICATIONS
For ELTs following the material recovery route, applications are endless but rarely follow the circular economy model. This is contrary to what is happening in other waste streams such as plastics and metals.
Applications depend mostly on dimensions:
Tyres also contain significant amounts of steel wiring which can be fully recovered and used as raw material by the steelmaking sector.
ELTs following the energy recovery route are basically used as alternative fuel.
