/ Technology

A Good Tire Fire: Tire Pyrolysis

The body ply of a tire is the major and largest component of a tire. It is generally made by one layer of rubber, a reinforcing plastic sheet and another layer of rubber. This layering can continue as the tire needs for the strength in its intended use case with things like aircraft tires having generally a considerable number. Sometimes this is called the carcass of the tire and it is just underneath the tread, on very worn tires you can see it. It is generally regarded as very difficult to recycle and in the United States of America over 100 million pounds end up in landfill each year.

Tire Pyrolysis is essentially putting shredded tire material into a big sealed cauldron and then heating it up in the absence of oxygen. This yields useful products for recycling like the steel, carbon black and tire derived fuel.

Tire derived fuel or pyrolysis oil is an interesting type of fuel. It is considered to actually have less greenhouse emissions than comparable traditional fuels. This is due to what is essentially a double filtration process, to produce the tire the petrochemicals were refined into the correct chemical profile for tire manufacture. Then with Tire Pyrolysis the tires were melted down and the output filtered to create a useful tire derived fuel.

This tire derived fuel is then used to power cement plants. However this use is still controversial as there is some thought that dioxin emissions could be damaging to the environment and that these concentration are specifically high in burning rubber.