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Besides being unsightly and taking up valuable land space, tyre dumps and stockpiles present many environmental concerns. When waste tyres are buried they have a tendency to “wiggle” their way to the surface over time causing problems for landfill sites. When tyres are stockpiled above ground they form mountainous piles that are at high risk of catching fire. When fires do break out – usually caused by lightening strikes – they can be extremely difficult to extinguish, sometimes burning for several months. Stockpile fires cause pollutants being released into the environment. Oil as a result of the burning tyres enters the groundwater and nearby rivers and thick black clouds of smoke full of toxic gases are released into the atmosphere. Even when fires don’t break out, tyre stockpiles are breeding grounds for pests such as mosquitoes and rodents.
Worldwide, an estimated 1.2 billion waste tyres are generated each and every year. Only a fraction of these tyres are currently recycled with the majority being incinerated, dumped or stockpiled.
The United States generates over 240 million waste tyres every year and the number of tyres in the country’s stockpiles is estimated to be more than 500 million, some experts estimating as much as 3 billion.
Australia generates around 18 million every year with roughly 20 million stockpiled.
Japan generates about 100 million every year with approximately the same amount currently stored in stockpiles.
In 2002, it was estimated that 250 million tyres were disposed in Europe and an estimated 3 billion were stockpiled.
To say the least, waste tyres pose a very significant environmental problem.
The Molectra® process has the capability to handle all sizes of waste tyres ranging from small passenger car and motorcycle tyres up to heavy truck, tractor and even earthmoving vehicle tyres.
The Molectra® process does not generate any leftover waste or residue since the entire tyre is recycled at every step of the process. Every component that is inside the tyre is extracted cleanly into a marketable end-product.
Since the Molectra® process is operated mostly under negative pressure and vacuum, pollution has been almost completely eliminated. There are absolutely no emissions from the system and dust, odour and noise are greatly minimised. Compared to many other recycling methods, the Molectra® process is extremely clean and pollution-free.
The primary materials extracted from the tyres are:
- Crumb Rubber
- Carbon
- Hydrocarbon (Oil)
- Steel
- Plastic Fibres
All of these by-products are used to manufacture further value-added products that have higher market value and demand. Click here for a full list of value-added products.  In an average tyre weighing 10 kilograms there is on average 1.2 kilograms of steel, 1.2 kilograms of plastic fibres and 7.6 kilograms of rubber. The Molectra ® process is remarkably flexible with its ability to switch between production streams to satisfy market demands. The clean rubber can be sold to the crumb rubber market or it can be put through the vacuum microwave unit to extract the carbon and oil (approximately 1:1 ratio). Alternatively a combination of all three products (rubber, carbon, oil) can be made – the more carbon and oil produced, the less rubber goes to the crumb rubber market. Unlike other tyre recycling methods, the Molectra ® process:
- recycles 100% of the tyre material;
- generates zero waste, no pollution and no residue;
- is very energy efficient;
- has low operating costs;
- has a flexible product output stream;
- produces both crumb rubber as well as carbon and oil;
- has significantly less wear & tear on the machinery;
- generates products that are clean, pure and high quality;
- creates a myriad of value-added products
No. Since the Molectra® process focuses on producing value-added products from the vulcanised rubber from tyres, there is no need to separate the rubber into natural and synthetic components.
Yes, it is possible to build a Molectra® resource recovery plant with less than 3-tonnes per hour capacity, although the payback period would be extended which is why we recommend a minimum of 3-tonnes per hour capacity.
Yes. Conventional heating methods have been tested with the pyrolysis and incineration recycling methods. Although these methods manage to extract some oil and/or energy from the tyres, the heating methods prove to be very expensive and energy intensive. Microwave energy has been proven to be the most efficient heating method.
With the Molectra® process, the three primary components of the tyre (rubber, steel and fibre) are completely separated from each other. The resulting crumb rubber is clean and suitable for many value-adding options. Subsequently, the carbon and hydrocarbons extracted from the rubber feedstock are free from any contaminants found in other processes (like pyrolysis) making them much more valuable commodities.
The products generated by the Molectra® process have been scientifically tested by several independent laboratories with excellent results. A short summary of these results is outlined below:
- Molectra® rubber crumbs absorb microwave well with an impressive rate of temperature rise unlike raw tyre crumbs;
- The rubber crumbs do not have any metallic or thread contaminants;
- 53% of the rubber feedstock is recovered as carbon which is 97.3% pure;
- 47% of the rubber feedstock is recovered as oil and has a calorific value (CV) of 42.5MJ per kg, which is about the same as diesel oil;
- The microwave process requires less than one-fifth of the energy from oil recovered;
- The oil was found to be composed of over 250 individual compounds, with a high degree of unsaturation;
- Steam activation of the carbons produced significant porosity and surface area. The surface area, methyl blue and iodine number were all in the range of commercially available activated carbons. The friable nature of the carbons would make them suitable for powder applications.
During the manufacturing process of new tyres, virgin rubber is blended with carbon black, oils, sulphur and zinc oxides, etc and then heated to form a very strong and resilient material. This is called “vulcanised” rubber. It makes the modern tyre almost indestructible which is one of the reasons why many companies have had difficulty to effectively recycle tyres.
The Molectra® process produces marketable products that are economically competitive with those already on the market. The research team at Molectra® has developed numerous value-added products that have specific markets. These markets cover the construction, mining, agricultural, gardening, sporting, equestrian, home-renovation and automotive industries.
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