Tyres & Rubber
For many years, we have marvelled at the progress made around the world in collecting end-of-life tyres (ELTs) and putting them to further good use. Latest figures confirm tyre recovery rates of 92% in Japan and around 80% in the USA, but Europe continues to lead the way on 93%.
Latest data from the European Tyre and Rubber Manufacturers’ Association (ETRMA) indicate that granulation activity in the EU-28 plus Norway, Serbia, Switzerland and Turkey surged a further 9.3% in 2016 to reinforce its dominant position in Europe’s treatment of used tyres, accounting for around 75% of the ELTs destined for material recovery.
But when these figures are updated at some point in 2019, they may well tell the beginnings of a different story. A general decline in retreading activity has led to an increased flow of available casings and a subsequent saturation of the granulation marketplace. Alongside this trend, the last two or three years have brought an explosion in negative publicity within Europe and America surrounding the use of ELT-derived rubber granulate as infill for playgrounds and sports pitches – undoubtedly the major outlet for operators of granulation equipment.
Over this period in the USA, indeed, it has been estimated that demand for this form of rubber infill has slumped around 30%. States and municipalities in the USA have continued to propose bans or other sanctions on the use of crumb rubber in playgrounds and sports pitches.
As reiterated at both of our Tyres & Rubber Committee meetings in 2018, such actions by municipalities and other authorities fail to reflect latest scientific thinking: around 100 separate studies have reached the conclusion that use of crumb rubber in the aforementioned applications carries no risk to humans or to the environment.
The problem for the sector lies in the fact that, despite the prodigious weight of evidence, many of those responsible for purchasing decisions are still turning their back on granulate derived from used tyres. Experts at our meetings have suggested that buyer confidence is likely to be restored only when a highly-respected, multi-agency research team comes forward with a definitive, plain-language vindication of this versatile product.
Such studies are being undertaken and there is reason to hope 2019 may provide the authoritative certainty craved by the crumb rubber sector. For example, industry itself is working to assess exposure and potential risks to human health associated with the use of ELT recycled rubber crumb in synthetic turf fields.
Meanwhile, the European Chemicals Agency (ECHA)/EU Commission will continue to look into possible health impacts of other substances contained in granulate derived from ELTs and there could be further investigations into environmental effects. In addition, BIR has called on the ECHA to introduce a harmonised system of judgements for rubber granules. The agency’s opinion is expected by September this year at the earliest.
Throughout the coming period, the recycling industry must continue to promote the positive messages surrounding this product.
But with the granulate market thus stressed both by saturation and vilification, and with regulatory scrutiny of this sector likely to increase rather than diminish, it is essential that other applications for ELTs are considered, developed or expanded. At our meeting in London last October, Fazilet Cinaralp of the ETRMA identified asphalt rubber as the outlet with the most potential for growth given its proven benefits, including noise and other environmental advantages. And in Barcelona several months earlier, Alicia Garcia-Franco of the Spanish recycling federation FER argued that green public procurement had a potentially huge role to play in the development of outlets for ELT-derived products.
And so we begin a new year at something of a turning point for the scrap tyre sector. Huge progress has been made from the dark days of the 1990s when the volumes of ELTs going for material or energy recovery were outweighed by the quantities consigned to landfill. Now the challenge is to find a new balance within the market to ensure that sustainable end uses can be found for ELTs long into the future.
by Barend Ten Bruggencate
Recybem BV (NLD)
Chairman Tyres & Rubber Committee 2015-2018
TYRES & RUBBER COMMITTEE CHAIRMAN
Max Craipeau
Greencore Resources (CHN)
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%.
RECYCLING PROCESSES
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.
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.
ENERGY RECOVERY
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.
TYRE PYROLYSIS
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.
RECYCLING FACTS
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In 2018, over 3 million tonnes of ELTs were recovered in Europe, representing a treatment rate above 96%.
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Taken together, Europe, the USA and Japan have an average ELT recovery rate of 90%.
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ELTs used as fuel are on average 80% cheaper than coal while having 110% of its heat value.
