Turkmen inventor finds new cost-saving ways to recycle rubber and plastic waste

By Gennady Galifanov, Patent attorney, Ashgabat, Turkmenistan

Recognizing the pressing need to tackle environmental pollution from industrial and household waste, Eldar Rizayev, a young Turkmen entrepreneur, has been exploring ways to convert garbage into a secondary raw material for the manufacture of economically useful products. The conversion of plastic and rubber waste materials, including worn-out tires, has been a particular focus of his work.

The technical nature of the problem

Repurposing waste into secondary raw materials for the manufacture of new products is an attractive, albeit challenging, solution. The disposal of rubber is particularly onerous. Waste rubber decomposes extremely slowly – it can take more than a 100 years for them to break down. On top of this, the disposal of rubber produces high levels of air pollution; every ton of burned rubber waste produces more than 250 kilograms of soot and more than 400 kilograms of toxic gas. The huge amount of highly flammable rubber waste in landfill sites also poses major environmental and health problems and creates a convenient habitat for rodents and insects, many of which are sources of dangerous infectious diseases.

For more than a century, attempts to regenerate used rubber products have failed, largely because they are made from thermosetting polymers, which typically do not melt when heated. As such, the ability to convert these waste materials into feedstock for the manufacture of new rubber-based products has remained elusive.

Changes in the policy landscape create incentives of recycling rubber waste

In the past, spent rubber products were usually incinerated. In line with EU Landfill Directive 1999/31/EC , in 2003 the European Union banned the incineration of waste rubber and the disposal of tires to landfill. Three years later, in 2006, the disposal of waste rubber (including shredded tires) at landfill sites was also banned. Organizations like the European Tyre and Rubber Manufacturers Association (ERTMA) have been working with policymakers to develop a supportive regulatory environment for consumers, drivers and the European tire industry.

These changes to European law prompted many countries to build processing plants to convert rubber waste into rubber crumb (from end-of-life tires), using a process that does not change the material’s chemical structure. The rubber crumb is then combined with polymer binders − hardeners, polyurethane adhesive, heterophase chemical polymer − to create various building materials and road surfaces. However, the use of these binders is expensive and significantly increases the cost of converting this waste into products for subsequent use. That is why the rate at which spent rubber products are processed is far lower than that rate at which rubber waste is accumulated. Recent data indicate that globally around 1 billion waste tires (around 17 million tons) are generated every year, with 75 percent of end-of-life tires going to the landfill.

Over the last 25 years, various incentives have been put into place to encourage the recycling of waste rubber, with positive results. For example, in 2018, countries like Norway, Serbia, Switzerland, Turkey and European Union member states have collected and treated over 90 percent of waste tires ; an increase of around 4 percent on figures for 2017.

Mixing rubber and plastic waste: a new idea to reduce costs

With the expected global rise in tire production – it is forecast to rise from 2.1 billion units in 2020 to 9 billion units in 2029, according to Garner Insights – the tire recycling market presents business and growth opportunities.

Recognizing this opportunity, as well as the need to reduce the cost of rubber recycling and the high cost of polymer binders, prompted Eldar Rizayev set about finding new ways to recycle both rubber and plastic waste and convert them into useful products. Unlike rubber waste, plastic waste consists of thermoplastic polymers, which melt when re-heated and can be re-purposed relatively easily to create diverse useful products.

Eldar Rizayev, a young Turkmen entrepreneur, has been exploring ways to tackle environmental pollution by converting plastic and rubber waste materials into a variety of useful products.

Mr. Rizayev began investigating the possibility of combining thermosetting polymers (characteristic of rubber waste, which do not melt when heated) with thermoplastic polymers (characteristic of plastic waste, which does melt when heated) to mold a variety of new products from the resulting molten mixture. He began testing his idea using polyethylene terephthalate (PET), derived from plastic bottles, and other containers we use every day. This was an easy decision, as his research demonstrated that that more than 80 percent of all solid household waste made from rubber and plastic is not recycled and represents a potentially valuable raw material to produce a variety of useful products.

The results of his experiment exceeded all expectations. When mixed with rubber crumb and heated in an extruder to 220-240°C, the crushed PET created a chemical reaction that resulted in the formation of a polymer-rubber mixture that could be used to mold a variety of hard-wearing and durable flooring materials with anti-slip properties, including tiles, thin slabs, rugs, carpets and mats for gyms and children’s playgrounds.

Unlike the standard process of combining rubber crumb with polymer binders, Mr. Rizayev’s process merges molten rubber crumb with the molten PET to create a new mixture with additional valuable properties.

To optimize the copolymerization process, the inventor tunes the technical process to the specific properties of each waste product used to create the molten mixture, which then passes through a three-section extruder to a series of molds for different outputs.

Mr. Rizayev’s solution stands out in that it produces a molten mixture with new, non-obvious and previously unknown properties. Thanks to this breakthrough, the process of converting rubber and plastic waste into useful household and construction products is more cost-effective and efficient.

Buoyed by his success, Mr. Rizayev continues to explore new ways to recycle waste rubber using other types of plastic, which are in plentiful supply, including polyethylene, polystyrene and polypropylene, and has completed various technical studies on his work. A 2018 report by the United Nations Environment Programme estimates that global plastic waste amounts to around 300 million tons every year, much of which ends up in landfill sites. Through his work, Mr. Rizayev is helping to resolve a major global recycling challenge. Where many generations of scientists and inventors have failed, he has succeeded in solving the crucial dual task of recycling rubber plastic waste. His innovative solution is an important step towards tackling the global problem of industrial and domestic waste.

Patents behind the invention

Mr. Rizayev’s work has resulted in the grant of patents from the State Service for Intellectual Property of the Ministry of Finance and Economy of Turkmenistan (Patent Nos. 608 and 628) and the Eurasian Patent Office (Eurasian Patent Nos. 028388 and 033283). He has now fully integrated these patented processes into his business operations and is producing recycled rubber and plastic products on a large scale.

Despite the coronavirus pandemic, Mr. Rizayev and his staff of 14 people have been able to produce and sell products worth over 10 million manats (approx. USD 28.6 million). The inventor continues to advance his scientific and experimental work in response to the strong demand for the waste-derived materials he produces from construction companies and sports and other organizations.

Mr. Rizayev continues to invest his time and energy in developing exciting new opportunities to repurpose the world’s waste materials.

Keen to license his technology, Mr. Rizayev is already in preliminary negotiations with various companies in the Russian Federation. Due to financial constraints, he has been able to patent these technologies only in a limited number of countries, but as his financial situation improves, he hopes to be able to protect them more extensively.

Mr. Rizayev continues to invest his time and energy in developing exciting new opportunities to repurpose the world’s waste materials. A number of new technologies are in the pipeline which combine different types of waste with new materials, such as barchan sands from Turkmenistan’s Kara desert, to cut costs and make stronger and more resilient products, including railway sleepers, baffles for sea and river berths, electrical insulators, road products, foam-backed carpets and more durable sports mats.