ARTICLE
This article is about issues of the circular economy and in particular about the recycling of used vehicle tyres, which, as opposed to their collection and transport, is a technically difficult and costly process.
The used vehicle tyres belong to the non-municipal waste category. According to the National Waste Management Plan, they are industrial waste but under extended producer responsibility management.
In Greece, approximately 40,000 tonnes of used tyres are discarded annually. There are more than 3,000 disposal points in the country that also work as waste collection points for the approved Collective System for Alternative Management (CSAM) for End of Life Tyres ECOELASTIKA. These points are basically the tyre repair shops and garages of the country where the new tyres are replaced with new ones.
Since the collection of used tyres takes place at the points of waste disposal we can talk about “collection at the source”. This fact is of particular importance because, in this way, the mixture of tyre waste with other types of waste is avoided and the used tyres are delivered “clean”.
In general, the collection and transport of end of life tyres is an easy process with high collection rates compared to the number of tyres being discarded. The main reason is that scrap tyres as waste are considered negative value goods for the market. In addition to that, storing them for a long time burdens their holders due to their bulky nature as well as due to potential risk of being a source of infection or a material capable of spreading fire. While their collection is easy, their transport costs are extremely high because of to the bulky and heavy nature of the scrap.
After their collection, most of the clean and free of other waste used tyres (approximately 65%) are sent to recycling units through the CSAM ECOELASTIKA. In these units, the used tyres are shredded, naturally separated and granulated in order to produce the final products. The main product of this process is the granulated tyre which is produced in various granulometries depending on the type of its future application.
The main use of tyre crumb is for artificial turfs for sports fields, safety rubber tiles, sports flooring, anti-vibration, soundproofing and heat-insulating materials for constructions, asphalt rubber and more. All these uses of scrap tyres are considered recycling. Furthermore, mechanical treatment for end of life tyres leads also to the production of by-products such as textile fibres and steel wire. These materials, depending on their purity, are led either for recycling in foundries (steel wire) or for energy utilisation (textile fibres).
Unfortunately, the rubber regenerated through the mechanical processing of end of life tyres, can be used only in small quantities for the production of new tyres. In this field, a great effort has been made in recent years concerning the mobilisation of new technologies on the one hand and the elaboration of large research studies on the other, in order to increase the utilisation rate of the regenerated rubber for the benefit of both the companies themselves and the circular economy. Recycling of used tyres (as opposed to their collection and transport) is a technically difficult and costly process. This is due to the high durability of the tyres which have been manufactured to resist wear from road contact and at the same time to provide protection to the passengers.
In the last 20 years, the rubber crumb produced from recycled tyres and available at the European market has been multiplied as a result of the application of the extended producer responsibility system by the majority of Member States. The organised production of rubber crumb by hundreds of companies founded in these 20 years that are active in Europe and cooperate with the approved CSAM of the Member States has contributed to that situation. In this way, in EU countries (including Greece) more than 700,000 tonnes of rubber crumb are produced and available for sale, a material seeking ways to enter the production cycle of other products, such as artificial turf for sports fields, safety rubber tiles, sports flooring etc.
The market’s need for rubber crumb does not seem to absorb the large quantities produced in the EU countries and that leads to a great drop of the product's price in the last 20 years, following the supply and demand law. It is therefore necessary to continuously expand the range of applications in which the rubber crumb can be used, for the recycling process to operate smoothly and its production units to be viable in the future.
A significantly smaller percentage of the collected used tyres is delivered, under the stakeholders’ responsibility, to approved cement producers for energy recovery due to its high heating value (7,500 kcal/tn). That use is known as “co-incineration” because the material is utilised in existing energy-intensive industrial units, such as the cement industry, where a percentage of conventional fuel is substituted with alternative ones. The co-incineration of used tyres is an absolutely safe energy recovery process which does not produce any pollutants other than those emitted from the use of conventional solid fuel under controlled conditions such as those prevailing in the kilns of cement industry, with temperatures above 850°C. Co-incineration does not produce dioxins and PCBs because the chemical composition of the tyres does not contain halogens.
All the textile fibres contained in tyres are used for energy in the cement industry, produced and accumulated as by-products in the tyre recycling plants. Like tyres, textiles fibres are included in alternative fuels used widely by the cement industry inside and outside the EU.
The new “European Green Deal′′ provides a transition plan to circular economy targeting to make the EU climate neutral by 2050, while ensuring financial and technical means to achieve this goal. The extended producer responsibility as a management model for certain waste, including used vehicle tyres, is a guarantee for the increase of the recycling targets of these materials. The reason is that private producers of future waste are obligated to finance the recovery of materials that complete their life cycle, applying the “waste hierarchy” established in the relevant European legislation, according to which, reuse and recycling precede other recovery methods (such as energy recovery) and landfilling or incineration are the last options.
With the management of over 90% of all discarded tyres in Greece and with high recycling rates (over 60%), Ecoelastika contributes decisively to the goals of circular economy and thus to the limitation of the climate change phenomenon.
The fact that the products of recycled end of life tyres do not “complete” the cycle of new tyres production does not decrease the importance of the great environmental benefit deriving from their alternative management, as:
• The new products made from rubber crumb, such as safety tiles, can (to a significant extent) be recycled and used for the production of new tiles of equal quality. Furthermore, a process has begun for the artificial turf for sports fields to be recycled leading to the recovery of the basic materials from which they were made, such as plastic, rubber crumb and quartz sand.
• If all end of life tyres were burnt for energy recovery, they would release large amounts of carbon dioxide to the atmosphere, which is one of the basic greenhouse gases and contributes to climate change
• The illegal burying of end of life tyres in landfills or their uncontrolled distribution would have multiple negative effects in the environment because of the risk of fires and their extremely durable structure that basically makes them non-biodegradable.
In the last 5 years, Ecoelastika has carried out 65 actions in Greek public schools by constructing free safety rubber flooring for their school yards. The aim of the project is to inform and raise citizen awareness regarding not just the recycling of tyres but the environment, the society and the circular economy in general.
It is organised and published every year on Ecolastica Facebook page: facebook.com/ecoelastika.
Based on the given information and the relevant photographs, Ecoelastika examines all schools proposed by the participants, evaluating where safety flooring is required. From this evaluation, a number of schools that meet the criteria posted on the official account of Ecoelastika on Facebook https://www.facebook.com/ecoelastika are selected by lot.
Our goals for the coming years are the continuous research for the development of new recovery methods and the expansion of the range of final applications and products where the regenerated rubber (as result of the physical treatment of tyre waste) will be able to replace raw materials and give alternative new reliable products that would compete on an equal footing with conventional ones.
*More information on the materials that can be produced by recycled tyres can be found on our website www.ecoelastika.gr