A Glimspe into the Tyre Derived Fuel Industry

WHERE YOUR TYRES GO WHEN YOU HAVE NEW ONES PUT ON YOUR CAR

Most people seem to be unaware of where their used tyres end up once they have them changed over. I believe that a lot of people would be surprised they learnt that a great percentage in tyres are actually burnt for fuel/energy purposes. This blog is a brief description on some of the uses for second hand tyres and a look into this industry as an effective way to dispose or recycle millions of used tyres. This industry also has many experts with ongoing concerns about some of the recycling processes and inconsistent burning techniques with various methods and equipment used.   

When writing this blog on Tyre Derived Fuel or TDF, I didn’t realise that there is two sides to the story. On one side is the industry using this resource of burning tyres either whole or shredded for fuel and processing tyres into oil and colour for plastics.
The other side is an environmental issue of dangerous toxic chemicals being released into the atmosphere when Tyre Derived Fuel isn't burnt properly or burnt by insufficient furnaces. Testing results for emissions over the last decade has been inconsistant with tyres burnt being mixed with coal with different types of furnaces being used burning TDF at various temperatures.

When you put your car new tyres most people presume that the used tyres that stay at the service will be recycled into road base or other secondary uses. U.S Scrap Tire News Website state that more than 52 percent of the 300 million scrap tyres are consumed as Tyre Derived Fuel. On the web-site appropriately named Scrap Tire News, it claims that in 2009 the U.S Environmental Protection Agency (EPA) described TDF as a high Btu-value fuel with lower emissions than comparable traditional fuels such as coal.

The Buying  Process

When tyres are replaced the consumer usually charged at a cost of usually about two dollars a tyre as a disposal fee and left with the dealer. The tyres are then picked up by a second hand tyre business at the cost of the new tyre dealer for a price negotiated between the two parties. This is usually a service fee payed by the new tyre dealership at around $1 dollar or so. Second hand tyre dealers compete for the discarded tyres and the dealership will offload to the lowest bidders for the tyres to be taken away.

The Storage and Manufacturing Process

A percentage of tyres are taken back to industrial areas or large storage sheds for resale for secondary uses in domestic markets. Products made from the recycle of tyres can be road base material or to make more tyres. It has been claimed however that most of the second hand tyres will be used for tyre derived fuel in overseas industries. The tyre derived fuel or as industry call it TDF is exported to markets throughout Asia to fuel power stations and cement kilns. Whole or shredded tyres when burnt at high temperatures are a substitute for coal or other burnable fuels and TDF Industry reports this to be a cleaner source of energy than burning coal. In cement manufacturing TDF industries claim that there is no smoke, odour or visible emissions from the burning of the tyres as the ash is incorporated into the final product. TDF industry also reports that the steel portion of the tyres also becomes a component of the cement product replacing some or all of the iron required by the cement manufacturing process. Paper mill industries also benefit from the use of TDF with a higher heat value than the wood waste fuel usually used. This high heat content, low price compared to other fuels and low moisture content make this fuel attractive to the pulp and paper mills industry.

A Chinese company claims a breakdown in reused tyre products after pyrolysis treatment as 45%-55% fuel oil, a product called carbon black at 30-35%, steel wire at 10-15% and flammable gas at 8-10%. The information in this figure below is taken from http://huayinenergy.com

Final Products	Application
Fuel oil (45%-55%)	Used as heating material to be sold to different industrial practices such as cement, steel, ceramic, glass, boiler and electric power.
Carbon Black (30%-35%)	Made into pellet or briquettes as heating material. Reuse for tyre making. Colour master batch for plastic industries
Steel Wire (10%-15%)	Sold to steel manufacturing.
Flammable gas (8%-10%)	Substitute for coal/wood/oil/natural gas to be fuel by furnace heat reactor.

Scrap Tire News (USA) say that  E.P.A order of preference in the management of scrap tyres is

1.  Reduce                                           2. Reuse.                          3. Recycle.              4. Waste to energy 
5. Disposal in an appropriate facility

Cause for Contraversy

Energy Justice Network (website) provide a strong case against the use of tyre derived fuel. They have claimed that E.P.A testing is inconsistent due to different burning temperatures and various industry practices and equipment used. They put forward a strong case on their website backed by credible academic experts on air control quality, most stating that inconsistent burning practices, burning at various temperatures and break down of temperature control systems can make TDF dangerous and toxic. Some testing of practices of burning tyres for energy have high amounts of nasty toxic chemicals such as dioxins and furans that are emitted from the incineration of chlorine-based substances in tyres. Also non-chlorinated hydrocarbon pollutants are butadiene and styrene are also produced.

Heavy metals are also present in tyres with up to 20 different metals in tyres that Energy Justice Network claims aren’t destroyed in the burning process, since they are elements. Energy Justice Network also claim that a tested Colorado cement kiln burning TDF with coal in 2002 had an 8% increase in Mercury when TDF was used.

OTHER PROBLEMS

Stock piles of waste tyres have been reported in local Brisbane and Sydney newspapers are causing problems as a source of mosquito breeding and fire risks (toxic blazing) when left outside in unlawful waste facilities. The Sydney Morning Herald in 2014 reports that the equivalent of about 48 million tyres are discarded in Australia annually, with many of them ending up in landfills, dumped or exported. EPA regulations have been tightened up over the last few years so illegal stockpiling is reduced to a minimum. A second hand tyre recycling business when operating without a license and without a council development application can receive fines up around $85,000.

Bushfires came within a couple of kms of a massive tyre dump near Stawell in western Victoria. Photo: GDT

More controversy occurs when tyres are not recycled in Australia and are sent to China or other countries for burning energy/fuel requirements. Tony Moore from Sydney Morning Herald in 2010 reports that an industry leader had spoken out on the problem back then and stated “That a loophole in government regulations, which listed tyres as regulated waste rather than a hazardous waste had allowed the tyres to be mass exported.” “One of the problems at the moment is that the tyres are being baled and sent to China for dubious reasons.” (burning tyres to fuel kilns or power stations). The main problem here is that local tyre recyclers may struggle to source enough rubber to meet demand for secondary sources like adhesive manufacture for the bitumen in roads when the mass export of tyres to China reduce this resource. When businesses secure lucrative business export deals and can source enough stock it can be an easier and more profitable method for them to cash in on the Chinese demand for this fuel. It was reported that 11 million tyres were exported to China and Vietnam from Australia in 2009.
As tyres are discarded at a mass disposal rate globally it seems methods of disposal and industry practice are being mostly unquestioned or confronted with the industries burning practices.  The main concern for governments at this stage is to take action against the storage of large amounts of tyres in outdoor areas because of fire risks and mosquito breeding. It seems that what can be seen and appear obvious is what will be attended to and that burning tyres whether safely or not will just go on.