Garret Gillespie is out to revolutionize the industrial composting industry.
This week, with a U.S. patent in hand, he’s one step closer to that goal. A Canadian patent is expected to follow.
“It really is significant. To get a patent is not easy,” said Gillespie.
His invention is the Plastic Separator, a machine that takes plastics, stones and metal out of compost.
He has partnered with Cold Climate Innovation at the Yukon Research Centre to get the idea this far.
“Garret came to us with an idea,” said Stephen Mooney, director of Cold Climate Innovation. “And this is our open-door policy for any Yukoners to bring their idea forward.
“Our job is to help people like Garret with their idea and take their idea through research, innovation to commercialization.”
So far the machine prototype has gone through four incarnations.
An earlier version, the Plastovac, now lives on Vancouver Island where it is estimated to save a compost facility $250,000 a year in dumping fees associated with the disposal of compost that is contaminated with plastic.
The problem of plastic in compost is huge, said Gillespie.
“Plastic is just a ubiquitous problem, and is a side-effect of our economic system,” he said.
“There’s plastic everywhere. Plastic is contaminating just about everything we touch.”
People who want to buy compost for their garden don’t want to find bits of plastic in it.
Contamination levels can reach as high as 25 per cent, Gillespie said.
“There’s a bunch of charlatans out there marketing plastics as being biodegradable, when they’re not.”
People believe they’re using a biodegradable coffee cup, for example, so it ends up in the compost. But in reality it doesn’t break down.
“There’s a lot of greenwash going on here,” said Gillespie.
On top of that there’s just laziness - people who are not careful enough about what they put in the compost bin.
The end result is that a lot of the compost that industrial facilities produce is unusable.
At the Whitehorse facility, which Gillespie operated until recently with his company Boreal Compost Enterprises, about half the compost that comes in ends up in the landfill because it’s too contaminated, he said.
There are other machines designed to get the plastics out, but increasingly they just aren’t working well enough, said Gillespie.
“The problem is that the scope of plastic contamination seems to be growing, so they’re just not capable of coping with the degree of contamination.”
The top-of-the-line European models still often leave half the plastics behind, he said.
The latest incarnation of the Plastic Separator, on the other hand, is consistently removing 99 per cent of the contaminants.
It works using a combination of vibration and blowing air.
The compost is loaded into the top of the machine, and works its way through. The machine vibrates, which floats the plastic to the top. Air then blows the material off the top and out a chute to the side.
A conveyor on the other side pulls out rocks and pebbles, and a conveyor out the rear carries the finished compost.
The smallest model that Gillespie plans to build will process about five dump trucks worth of compost an hour. The largest may do three times as much.
Gillespie has partnered with a U.S. company that works in industrial agricultural machines to get some prototypes built.
Those will then be tested before rolling out into production. About $3-4 million will have been invested in the idea by that time, he said.
He expects that the eventual price tag will start at $250,000, and rise to half a million or more depending on the model.
But if the machine keeps as much compost out of the landfill as Gillespie expects, it will pay for itself quickly at an industrial facility.
“It’s basically an essential tool for moving towards zero waste,” he said.
Contact Jacqueline Ronson at