Medellin, Colombia — Around the world, discarded tires are piling up in backyards, gullies and landfills. They take decades to decompose unless they are burned, which releases toxic gases.
It’s a global problem, but a possible solution is taking shape in a warehouse outside of Medellín. That’s where Diego Castaño and small team of colleagues at a company called Procellantas are developing a method to recycle tires using microwaves.
He cooked up the idea six years ago when he owned a business selling tires. Searching for a way to recycle used tires, he found his only option was to send them to a landfill. So Castaño, a chemical engineer, started running tests in household microwaves and found that small pieces of tire material could be melted down.
Since winning a grant from the Inter-American Development Bank two years ago, Castaño has developed the technology further and has designed an entire microwave system with parts he’s had custom-made abroad.
In the coming weeks, he and his colleagues will test their first protoype. This is how it works: after a tire is placed into the microwave, jets of nitrogen gas stream into the oven at 600 degrees Celsius. As the tire melts down, it is reduced to its original materials – liquid and combustible gases, active carbon, carbon black and steel. Castaño says the idea is that all materials, except for steel, are returned to their original state, making them competitive in the marketplace.
“We are optimizing our process not only so that it has low environment impact, but so that the products are competitive and profitable,” said Castaño. “Because we won’t win much by having a very good system that has to be subsidized by the government.”
If Procellantas’ prototype works, Castaño will likely have tires rolling in from many parts of Colombia. A 2010 law requires tire vendors, importers and distributors to develop a used-tire management plan and to recycle 20% of used tires by 2012.
Eventually, Castaño hopes he can export the technology to other Latin American countries, and make a serious dent in landfills.