While we are all delighted at the prospect of a return to face-to-face BIR Conventions in 2022, our webinars over the last two years have proved invaluable in highlighting the wealth of innovation within the tyre and rubber recycling sector.
We have learned about Michelin’s BlackCycle project which has set itself the ambitious target of recycling almost 50% of Europe’s end-of-life tyres (ELTs) into new tyres just a handful of years from now, and about that growing band of businesses around the world which are successfully developing markets for various forms of non-ELT rubber scrap.
These developments have become even more important given the threat hanging over the crumb rubber infill market which, for many years, has absorbed a large proportion of the used tyres coming forward for recycling. Indeed, latest figures from the European Tyre and Rubber Manufacturers’ Association (ETRMA) covering 32 countries show that, of the 1.95 million tonnes of ELTs treated for material recovery in 2019, 1.36 million tonnes (or almost 70%) ended up in granulation processes.
Recycled rubber uptake has been boosted by the ever-growing number of brands which are looking to increase the recycled content of their new products in line with corporate environmental targets. This trend is certain to continue: for many companies in Europe and North America, environmental pressures have been trumping cost considerations for some time but, as we heard at the BIR Tyres & Rubber Committee webinar last May, the ecological imperative is now gaining traction further east too: Asmipudin Mohd Ali Jinnah of Malaysia-based Bridge Fields Resources told us that some Asian manufacturers are already willing to pay more for secondary raw materials so that they can put “recycled” on their product labelling; and fellow contributor Harsh Gandhi of major Indian tyre recycler GRP Ltd pointed to evidence of consumers allowing their suppliers more flexibility over recycled contents.
Our webinar in November last year offered a similarly positive perspective on recycled carbon black (RCB), with Germano Carreira of BB&G-Alternative Worldwide Environmental Solutions assuring us of the scope in the near future for RCB prices to exceed those of virgin carbon black in certain applications.
As in the plastics sector, therefore, we are seeing emerging potential for a permanent disconnect between recycled and primary prices, based ultimately on consumer pressure for more environmentally sensitive product manufacture. But as has been stressed by our regular webinar contributor Martin von Wolfersdorff of Wolfersdorff Consulting, success is still dependent on application performance and on how much recycled content can be incorporated into a new product without loss of key properties.
Despite the tremendous gains made over recent decades in terms of devising tyre/rubber recycling solutions and despite the positive shift in attitudes towards recycled materials, there are inevitable speed bumps along the road to continued progress. While the last couple of years have been unusual in many ways because of COVID, one constant has been the flow of retrograde legislation that has the potential to hinder the development and flourishing of recycling activities, including shipment regulations which inhibit cross-border movements of crucial secondary raw materials.
One solution for our sector could well lie in agreeing harmonized end-of-waste criteria for rubber derived from ELTs. Interested parties in several European countries have already pushed at the national level for firm criteria to identify the point at which tyre-derived rubber ceases to be waste and is categorized instead as a material. But as noted last October in a joint statement from the ETRMA and the European Recycling Industries’ Confederation, “a common starting point” for end-of-waste is essential to foster the circular economy and to increase the uptake of ELT-derived rubber in high-value end-use markets.
Meanwhile, our own Tyres & Rubber Committee, in conjunction with BIR, has sought to progress a dialogue at EU level aimed at introducing minimum recycled contents in rubber products. The possibilities must surely be worth pursuing given that I have seen with my own eyes how well this approach has worked for plastics.
Only through such innovative and unified approaches to demand-pull and control mechanisms will we create a sustainable global structure that extracts maximum benefit from recycling.
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.