In 2017, there were 80 million vehicles sold around the world. With four tires each, that's 320 million tires in just one year. What happens to all those tires when the vehicle is retired or when the tires are replaced? How is the Earth not completely drowning in used tires?
We're about to explore the ins and outs of tire disposal and recycling. We'll cover how tires are typically disposed of and explore some emerging alternatives that are gaining prevalence.
Tires Are Rejected at Landfills
Most landfills adamantly reject tires when they come in. Tires are 75% empty space, which means that empty space can be filled with methane. Once filled, they are prone to float or catch on fire, neither of which is good for a landfill environment.
Tires also never biodegrade, so they are in landfills permanently. Despite this flaw, some landfills are starting to accept shredded tires. In fact, many landfills are using shredded tires to cover or cap landfill sites since they trap methane quite effectively.
Having a specific landfill just for tires is one method that's been tried. The issue with this idea is that if a fire occurs, which is common, it can burn for months and give off a large amount of pollution. Tire piles are also often homes for vermin and mosquitoes, both of which can carry diseases.
So, Where Do Used Tires Go?
Tires may not be welcome at landfills, but they have to go somewhere. The primary methods for disposing of tires are as follows.
Cement manufacturing. Tires can be used as an alternative fuel source when manufacturing cement, which is the key ingredient in widely used concrete. Whole tires are thrown into cement kilns, and the extremely high temperature causes smokeless combustion of the tire. They are sometimes also shredded and fed into the other chambers used in the cement-making process.
>Products derived from tires. Several alternatives to cement-based combustion have been developed to provide more economic stimulation than simply combusting the tires. One of the primary alternatives is using shredded or whole tires as backfill for walls and bridges or helping build septic system drain fields. They are also being used to control erosion and guide runoff rainwater.
Pavement. Tires, along with other types of rubber, can be ground up and used in paving projects and some projects that use molds. They are used in many applications as a concrete alternative when appropriate.
Repurposing. While not a direct method of tire recycling, repurposing tires is something that's gaining prevalence in many communities. A tire swing is a simple example of repurposing a tire or using them in workout equipment. Sometimes rows of stacked tires are used as barriers in auto races to help soften the impact upon collision.
All Tires Need New Homes
While cement manufacturing's smokeless combustion is an excellent way to dispose of tires, recycling them is far superior. Hopefully, entrepreneurs and innovators will keep exploring ways to use this continually-available material.