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Billions of vehicle tires are removed and disposed of each year, but dealing with this rugged plastic, rubber and metal waste without harming the environment has proven to be an as-yet insurmountable global challenge. Innovative tire waste recycling companies such as Pretred – based in Colorado, US – may have the answer to the global waste tire problem.
The Global Waste Tire Problem
Various studies quantify the global waste tire problem at between 1 billion and 1.8 billion used tires disposed of worldwide each year. This represents approximately 2-3% of all waste material collected. The US alone sends between 246 million and 300 million end-of-life tires to waste annually.
The problem is also growing. With a rising population worldwide – especially among emerging middle classes in poorer countries gaining more access to vehicles – there comes an increase in vehicle use. As more miles are driven, more tires are replaced and more waste tires have to be dealt with.
What are Tires Made of?
Tires are made for durability and safety. Unfortunately, this is what makes them so difficult to reuse or recycle. Reducing tire consumption – especially in light of a growing global population with more wealth – could only happen if our economy and society can drastically reduce their reliance on vehicles for transport and shipping.
To withstand the rigors of millions of abrasion cycles on roads – and keep road users safe – the modern tire has to be constructed for its rugged application with tough materials.
Tires are made from natural rubber (19% of the material), synthetic rubber comprising butadiene, styrene, and halobutyl rubber (38%), synthetic polymer fabric strengthening belts (4%), reinforcing wire made of high-carbon steel (12%), and carbon black or silica fillers (26%). Antioxidants and antiozonants are also applied to tires to help them resist degradation.
What Happens to End-of-Life Tires?
End-of-life tires (or ELTs) – which are abundant and difficult to recycle due to the need for rugged constructions and tough materials – are a significant challenge to worldwide environmental efforts.
This global waste tire problem exists in the large amounts of landfill space taken up by tires worldwide. In Colorado, for example, there is a waste tire site with 60 million tires – 550,000 tons of material – dumped on the land. In addition, at least two-thirds of the billions of tires that become used around the world each year end up dumped in legal or illegal waste sites.
Waste tires piled up like this attract disease-carrying rodents, make the land they are dumped on useless, and emit harmful chemicals into the atmosphere as they begin to decompose slowly.
Waste tire dumps often catch fire due to their size and flammability of tire materials. Some waste tire fires can burn for up to nine months as millions of tires piled up slowly burn away.
Burning tires release carcinogenic and mutagenic toxins into the atmosphere, and so they can only be relatively safely incinerated using advanced air emission control systems. Unfortunately, such systems are expensive: they are inaccessible to waste management in developing countries and often not profitable enough in larger economies.
Used tires are often found discarded in natural environments, in rivers, and in oceans. For example, some researchers estimate that 10-28% of all micro-compound waste in the sea is from used tires.
Tire Waste Recycling
Tire waste recycling is becoming an increasingly viable answer to the global waste tire problem. While only 13% of waste tires are recycled each year, public intervention and industry innovation have made recycling the primary method for waste tire management in Europe – which now recycles 39% of all waste tires.
There are more instances of used tires being recycled as chips for playgrounds, athletic and sports fields, and in construction. Novel uses in land management and the built environment have also been put in place.
Due to the tough materials in tires’ construction, recycled tire waste is also a good candidate for rugged applications – often as a replacement for concrete. Green Rail Group in Europe manufactures railway sleepers from recycled tires – and Pretred is seeking to replace concrete in various applications with its tire waste recycling products.
Pretred recycles waste tires and heavy-duty plastics – solid waste products that are hard to recycle, produce and dispose of in large numbers worldwide, and create significant environmental risks as untreated waste.
The company, founded in Colorado by nature enthusiasts who grew tired of seeing durable plastic and tire waste in local rivers, repurposes recycled tire and plastic material into roadblocks and barriers for solid and durable industrial use.
Pretred’s recycled products replace concrete typically used for this application with the associated and well-documented environmental risks that accompany concrete manufacture and use. For instance, barriers require only 2% of the CO2 emissions as equivalent concrete products for their manufacture.
Can Tire Waste Recycling Tackle the Global Waste Tire Problem?
As Pretred recycles 60,000 tires and 27,000 kg (60,000 lbs) of plastic for every 1000 barriers produced, its model may have the scaling capacity required to tackle the vast global waste tire problem.
Considering the size of the growing problem, it is clear that innovations in tire waste recycling like this are needed.
References and Further Reading
Berendsohn, Roy (2018). “Our Waste Tire Problem Is Getting Worse.” Popular Mechanics. [Online] https://www.popularmechanics.com/cars/car-technology/a22553570/waste-tires.
Boucher, Julien and Damien Friot (2017). “Primary Microplastics in the Oceans.” IUCN. [Online] https://doi.org/10.2305/IUCN.CH.2017.01.en.
Kole, Pieter Jan, Ansje J. Löhr, Frank Van Belleghem and Ad Ragas (2017). “Wear and Tear of Tyres: A Stealthy Source of Microplastics in the Environment.” International Journal of Environmental Research and Public Health. [Online] https://doi.org/10.3390/ijerph14101265.
Kordoghli, Sana, Maria Paraschiv, Radu Kuncser, Mohand Tazerout, Malina Prisecaru, Fethi Zagrouba and Ionut Georgescu (2016). “Managing the Environmental Hazards of Waste Tires.” Journal of Engineering Studies and Research. [Online] https://doi.org/10.29081/jesr.v20i4.52.
Pretred. [Online] https://www.pretred.com.
“What’s in a Tire?” USTires.org. [Online] https://www.ustires.org/whats-tire-0.