A Genuine Green Solution for Used Tyres

Pyreco Featured in Tyre Trade News

A British company will provide a ‘closed loop’ pyrolysis process as an environmental option to existing disposal methods, by turning tyres back into valuable raw materials, energy and new products. 

Pyrolysis is a proven process that is capable of changing the form of many substances.  It has been used for hundreds of years and is today regarded as one of the most effective ways of dealing with a growing number of waste materials.

The obstacles surrounding its use for recycling tyres have tended to centre on the relatively poor economics of “batch processing” and difficulties in obtaining value from the end products.  Common concerns have been the viscous nature of the oils produced and a carbon char that has been described as an unusable clinker intermingled with fine steel shards.

An almost perfect answer to Directives

However, the resolution of these problems now means that the way is open for the creation of a “virtuous cycle”, a closed-loop recycling programme that turns used tyres into material suitable for the manufacture of new tyres; the almost perfect answer to several of the new European Environmental Directives.  The link-up two years ago between the UK company PYReco and Metso Minerals, a division of the Finnish engineering giant Metso Group Oy, has led to the recent announcement of PYReco’s planned construction of Europe’s first continuous flow pyrolysis plant for the recycling of tyres, to be located in the Tees Valley.  This represents the culmination of a 10 year research and development programme by Metso’s American pyro division and will result in a fully WID compliant plant, capable of processing and recycling 60,000 tonnes per year.

 

Delivering a working pyrolysis solution

“We need to change our perceptions of pyrolysis.  For too long the technology has been regarded as one that promised much but delivered little.  Those days are behind us and PYReco’s plant will demonstrate just how effective pyrolysis will become at solving this and other waste related issues,” says PYReco’s managing director, Noel Harasyn.

In its 2004 report on Emerging solutions for recovering value from scrap tyres (Technology Options and Market Opportunities), Juniper Consultancy Services – the world’s leading analyst of waste processing technologies – identified Metso as being the company most likely to deliver a working pyrolysis solution.

 

What is pyrolysis?

Pyrolysis degrades tyres using externally applied heat.  The chamber containing the tyres is oxygen free, so that tyres decompose, giving off gas, then oil, leaving a mix of char and steel which is then separated and further refined.  All of the material entering the chamber is accounted for in the various outputs.

The main part of the pyrolysis plant is the central heat chamber, a slowly rotating cylinder or calciner which has a series of burners along the outside to provide heat needed for the process.  Because the process takes place within a sealed chamber, there are no noxious emissions.  The shredded tyres enter via an auger and are dropped into an oxygen purge before being dropped into the calciner itself.  The gas and oil are drawn off as they vaporise, leaving the char and the steel to emerge ready for further processing.

The plant is destined for Tees Valley’s South Tees Eco Park (STEP), where it will recycle approximately 60,000 tonnes of shredded tyres a year – without waste or harmful emissions – and convert them back into their constituent parts:  steel, carbon black, oil and gas.  The plant will also be able to process other rubber materials arising from motor manufacture, typically belts and hoses, windscreen surrounds, wipers, floor mats and mud flaps.

The steel and carbon black will be sold back to industry.  However, in view of the widening UK energy gap predicted by the Carbon Trust for the next five years and beyond, PYReco has decided to use the oil and gas output from Phase One of the Teesside facility to generate electricity for the home market.  When it becomes fully operational, the plant will be producing 17 MW of electricity per year, with scope for the output to increase considerably. 

The Environmental Agenda

With the European Union urgently seeking ways to reduce its carbon footprint and protect vital strategic resources, the opportunities here are clear.  Most fuels from petrol, diesel, and heavier oils including crude, run at about 85 per cent by weight.

Two hundred and fifty million discarded tyre casing, or “arisings”, per annum, projected to rise by four per cent a year (EU Statistics and Freedonia Report) represents potentially 4 million barrels of recoverable diesel fuel, plus 4.5 million boe (barrels of oil equivalent) of syngas with a BTU comparable to Propane.
The greatest saving of all, however, would come from recycling the carbon black and steel.  Carbon black manufacture requires the burning of around 1.4 tonnes of oil for each tonne of carbon black so recycling Europe’s tyres would save the needless consumption of a further 6 million barrels of oil and avoid creating around 700,000 tonnes of CO2 per year.

This “displacement effect” also applies to steel.  BioRegional Reclaimed, funded by the Business Reuse Fund through DEFRA, has produced an Ecopoint Chart for Steel which indicates that recycled steel had an environmental footprint of less than five per cent of conventionally produced new steel.

A European Solution

At a time when there a growing requirements for the motor industry to increase its use of recycled materials in accordance with the ELV Directive to 95 per cent re-use and recovery by 2015, the availability of a “closed-loop recycling system” that takes one of Europe’s most environmentally challenging waste streams and returns it in a usable form for further manufacture, has to be a major advantage.

The benefits are two-fold.  Firstly, once a tyre reaches the end of its useful life it tends to become an environmental problem.  The UK Chemical Hazards and Poisons Division Report of December 2003, and the Massachusetts University Report on Toxicity of Tyres, August 1998 highlight some of the main concerns, so environmentally compliant recycling should be the preferred option.  Secondly, the materials held in a tyre are too valuable to waste and recycling makes economic sense, as well  as meeting the EU European Agenda. 
If environmentally compliant recycling is now a real possibility then it opens the door for co-operation between all sectors of the tyre industry:  manufacturers, distributors, collectors and shredders, to establish an industry wide retrieval scheme.  The tyre industry is now ideally placed to establish an environmentally compliant scheme.  Pyrolysis offers the process that will achieve these objectives.

“Over the last 25 years I have been looking to discover ways to reduce mankind’s footprint on our planet.  It is therefore of particular personal satisfaction to be able to see such huge benefits being attached to this plant and for those who purchase its products,” says PYReco’s chairman, Anthony Carter.