The science and business of biochar

It’s pretty obvious that there is something wrong with the soil at the far end of the Whitehorse Airport. “You can smell it,” said Katherine Stewart, raising her voice to be heard over the din of an excavator.

It’s pretty obvious that there is something wrong with the soil at the far end of the Whitehorse Airport.

“You can smell it,” said Katherine Stewart, raising her voice to be heard over the din of an excavator.

The entire area – part of a land-treatment facility owned and operated by Transport Canada – smells like diesel, but there’s likely some jet fuel in it as well, said Stewart.

“We don’t know the combinations of what’s in there, but it’s pretty good and contaminated,” she said.

As the project coordinator of the Northern Biochar for Northern Remediation project, Stewart and a team of researchers from the University of Saskatchewan and Yukon College will be looking at how to clean up sites like this.

Specifically, they’re investigating biochar, and how it can be used to help break down hydrocarbons in northern climates.

Biochar is basically just charcoal.

Although, unlike the briquettes used for cooking which contain toxic binding materials, biochar is made exclusively from organic material.

Created through pyrolysis – burning without oxygen – the result is a black chunk of carbon that contains millions of microscopic holes.

Those holes trap water and provide a habitat for microorganisms.

Yukon College has ongoing studies looking at biochar as a soil amendment for agriculture, but this latest project is looking at using biochar to help clean up fuel spills.

Initial research done by the University of Saskatchewan in Iqaluit last year found that in soils mixed with biochar, the microorganisms that break down hydrocarbons continue to work even in frozen conditions.

The reason, scientists think, is because the tiny perforations in the biochar help keep small amounts of water from freezing.

“You can actually have little films of liquid water still in the soil even though it’s frozen,” said Stewart. “That’s really important in the North, especially in Iqaluit because their soil is frozen so much of the year.”


Armed with those findings, the University of Saskatchewan partnered with Yukon College and applied for a grant from the Natural Sciences and Engineering Research Council of Canada.

The council awarded them $660,600.

It’s the first time that Yukon College, or any northern school, has received a grant from the council.

“It’s a pretty big milestone in terms of saying we’re going to start doing research in the North,” said Stewart.

For the next three years, Stewart and her research team will be studying the effects of biochar on contaminated soil they’ve taken from the land treatment facility at the airport.

Twenty-five bags will be filled with a mixture of biochar, fertilizer and soil.

They are studying three different kinds of biochar. Some of it is made from wood, some from bones and some from fishmeal.

At the same time, another set of researchers, in partnership with Nunatta Environmental, will be doing a parallel study in Iqaluit. At the University of Saskatchewan, with help from Federated Co-op., core samples taken from a contaminated site in Meadow Lake will be mixed with biochar and studied in the lab using the university’s synchrotron – a particle accelerator that can be used to examine matter on an elemental level.

All the biochar used in the Yukon portion of the project – with the exception of the one produced from fishmeal – is being produced locally, by Whitehorse-based Zakus Farms.

Owner Warren Zakus has been making biochar for more than a decade, although he used to just throw it away.

To demonstrate the dangers of syngas – the highly flammable hydrogen and carbon monoxide mixture that’s produced from pyrolysis – Zakus, then a training officer for the fire department, made a lot of it.

It was only five or six years ago that he found out that the stuff he was throwing out could be used in his garden.

He got a grant to build a biochar oven and partnered with Yukon College to investigate its use in agriculture.

“At one time I had four different projects going that all involved the college in one way,” said Zakus.

Those projects have yet to produce conclusive scientific results but he’s seen biochar make a difference in his own garden.

Unlike fertilizer, it doesn’t get used up, said Zakus. Once you apply it you don’t have to add it again.

“It just sits there like an artificial reef,” he said. “You stick it in and all the microorganisms move in because it’s there.”

The only problem for using it as an agricultural product is it’s expensive.

“You could buy some biochar, and get a little bit of a difference, or buy some manure or fertilizer and get a big difference,” said Zakus.

That makes it a tough sell to farmers, which is why he’s excited about the prospect of using it to clean up soil.

For this latest project, Zakus had to build a new biochar oven, his first one didn’t have the kind of quality control the project needed.

He already has plans to make a third, incorporating what he learned from the first two machines.

Helping spur local business is an added benefit to this project, said Stewart.
“The thing that’s really exciting about this project is that we’re building, not only capacity for doing science here at Yukon College, we’re also building capacity to develop biochar as a commercial product for the North,” she said.

“We’re examining how it works and helping … to get the right formula for northern soils.”

Contact Josh Kerr at