Factory can put mountains of old tyres to good use

Dubai alone has eight million discarded tyres. But the flammable and unsightly waste can be broken down and used to make irrigation lines.

Helgi Thor Jonsson, the manager of Leaky Pipe UAE, mixes rubber and plastic before it is used to create irrigation pipes.

ABU DHABI // A new factory in the capital could help rid the UAE of the mountains of discarded tyres accumulating at landfills and dumps. The official count for Dubai alone is eight million abandoned tyres. Millions more are lying around in Abu Dhabi, Sharjah and other emirates.

Tyres are highly flammable. When dumped at landfills they increase the risk of fire, already high due to the large amounts of methane gas emitted there. In addition, old tyres take hundreds of years to disintegrate. "The breakdown process of rubber is even longer than plastic," said Cameron Marland, assistant general manager at Zenath Recycling and Waste Management, one of the biggest waste management firms in the country.

Old tyres, said Mr Marland, were made of rubber, steel and cloth. Recycling a tyre involves segregating these materials first, then grinding and processing the rubber until it becomes a finely ground black powder known as "crumb". "The tyre recycling industry is a very difficult one," Mr Marland said, adding that profit margins were low. "The biggest problem is that no one here does anything with the end product."

The opening of Leaky Pipe UAE in Musaffah means that is now changing. For four months, the company has been using recycled rubber, or crumb, to produce sub-surface irrigation pipes. But so far, that material is coming from abroad. Dr Seif Nounou, the company's general manager, said the situation was not surprising because Leaky Pipe UAE was the first in the market to use tyre crumb in its manufacturing.

Discussions had been held with officials on the need to find locally produced recycled rubber, he said. In addition, the opening of the pipe manufacturer meant "there is now interest for companies to crush it down and there is a market for their products", he said. Leaky Pipe UAE currently operates a trial line with a capacity of 10,000 metres of pipes per day. The line uses about five tonnes of recycled rubber per week.

Demand for the product has grown. "We are planning to have two more lines," Dr Nounou said. The pipes are 50 to 70 per cent recycled rubber, with the rest polyethylene and other additives. The ingredients are melted and mixed so that the pipe has tiny pores in its surface capable of slowly releasing water. Dr Nounou said the "secret" to the manufacturing process was controlling the melting points for the various compounds so that they could be mixed.

The finished pipes leak between half a litre and 30 litres per hour. The pipes are buried from 10cm to 30cm below the surface and irrigate plants from below. Conventional irrigation systems spray water on plants from above the surface. "It is much more logical to have the pipes underground," Dr Nounou said. "The roots are underground and this is where the water needs to reach." Sub-surface irrigation could bring water savings of up to 50 per cent compared with surface irrigation, he said.

Since 2008, the company has carried out landscaping projects for the Environment Agency-Abu Dhabi, using products produced by its branch in Sweden. That branch had been closed with the opening of the UAE office, Dr Nounou said. "There is more use for our products here," he said. "In Europe, it is used as a complementary irrigation system. Here is a hot, dry climate and plants are 100 per cent dependent on irrigation."

Recycled rubber can also be used as an aggregate in asphalt, for shoe soles or to construct playing surfaces for sport or recreation. Last year, officials in Dubai and Abu Dhabi announced separate plans for tyre-recycling facilities, one in Dubai and two in Abu Dhabi. None of the three are yet in operation. [e-mail]