Published June 3, 2016
There are lots of ways scrap tires get recycled these days, between playground surfaces, athletic tracks, equestrian mats, rubber mulch, and rubberized asphalt, it would seem like the state of tire disposal is in good shape.
But in spite of the growing number of uses and markets for discarded tires, the vast majority of scrap tires still end up as tire-derived fuel, or TDF. It keeps a high percentage of tires out of landfills, but in terms of environmental impact, it has its drawbacks.
Here’s a rundown of what you should know about TDF.
An Alternative Fuel
Tire-derived fuel was first imagined as an alternative fuel. In terms of energy efficiency, it equals petroleum while being even more efficient than coal.
But instead of being burned on its own, it’s used as an additive. It’s frequently burned with coal, since fuel composed of coal and TDF produces more energy by volume than coal alone. In that respect, TDF represents an improvement to traditional coal and fossil fuels.
Plus, it’s using a waste product that would otherwise be causing serious problems and taking up a whole lot of space in landfills.
TDF has to be burned in combustion devices that meet specific guidelines, so it’s burned in industrial settings, including power plants and paper mills. As a fuel source for energy and other industries, TDF helps provide the energy to keep homes and businesses running.
And because scrap tires cost far less than fossil fuels, TDF has economic benefits for these industries as well.
Right now, TDF is the quickest and best way we have to use a large enough volume of tires to keep up with how much tire waste is produced each year. Unfortunately, it has some significant drawbacks.
The biggest concern is pollution. We know tire fires are extremely dangerous; burning tire shreds as TDF carries many of the same risks of pollution. In particular, it poses a risk to water, with chemicals entering storm water and threatening plants and aquatic life. Pollution released into the air is also potentially dangerous for humans and other animals to breathe.
The primary concerns include the introduction of zinc oxide into the environment, especially when it makes its way into water. Zinc oxide is poisonous to fish and other aquatic animals. It can also kill plants.
In terms of atmospheric pollution, a number of tests and studies have produced extremely varied results when testing the emission levels of fuels with TDF compared to fossil fuels alone.
Where To Go From Here
Over the last several years we have seen innovations in uses for scrap tires that constitute true turn-key recycling, turning one product (waste tires) into another (rubber mulch, equestrian mats, rubberized asphalt).
The problem is volume: there are simply too many scrap tires being produced each year for these recycled products to keep up. What’s needed now is innovation to find a low-impact, high-volume way to recycle tires into more useful products.