Lean Green Burning Machine

Flathead National Forest touts forest-management benefits of new mobile biochar production burner

By Micah Drew
A biochar creation demonstration using a CharBoss mobile biochar air curtain burner in Coram on Feb. 16, 2023. Micah Drew | Flathead Beacon

In a clearing on the Flathead National Forest outside Coram, a low bass-like grumble rippled the winter air. Gathered around a giant green machine and a large metal barrel, both emanating heat, were dozens of people representing sectors of the forest industry. 

It was a gathering that could easily be mistaken for an illicit party, complete with bonfires, if not for the excess of government trucks parked nearby, and Forest Service patches adhered to Carhartt jackets and hats. 

The gathering was prompted by the sedan-sized bright green machine that was continually loaded with branches and small tree trunks. From the bottom, a small conveyor belt pushed blackened lumps into a water-filled tray before the charred remains were raked out into a pile for examination. 

The CharBoss is a mobile air-curtain incinerator that burns biomass, such as slash piles left over after forest-thinning efforts, using a low-oxygen environment to produce a form of charcoal called biochar, a process known as pyrolysis. 

While traditional burning produces a large amount of particulate matter such as smoke and ash and releases carbon into the atmosphere, pyrolysis generates minimal smoke and renders the biomass as a high-carbon biochar with a variety of applications that appeal to private landowners and forest management agencies alike.  

A biochar creation demonstration using a CharBoss mobile biochar air curtain burner in Coram on Feb. 16, 2023. Micah Drew | Flathead Beacon

“There’s a whole lot of things we can do with biochar,” said Deborah Page-Dumroese, a Forest Service soil scientist who studies biochar use at the Rocky Mountain Research Station in Moscow, Idaho, and who was on hand for the CharBoss demonstration. “The nice thing is we’re putting a high-carbon product into the soil to sequester carbon, which can help us with a range of issues we’re having from climate change to water retention to soil health.”

According to Page-Dumroese, studies show that spreading biochar on agricultural fields have shown to effectively increase crop production by up to 42%, while the porous structure of biochar can improve water retention in soil by up to 20%. In addition, biochar-infused sites often show increases in native vegetation growth, as well as in pollinator plants and insects due to the enhanced soil health. In contrast, the current practice of burning slash piles can sterilize the soil for upwards of 50 years, according to Page-Dumroese.

“There are burn scars on the Flathead Forest that have been around for decades, with all organic matter gone,” she said. “While we’re still going to burn slash piles in forestry, biochar burners like this one give us an opportunity to do forest operations differently and think about climate smart forestry.”

Utilizing biochar is a centuries-old forestry practice but has become more common in recent years as companies and land management agencies work to scale up production methods.

The CharBoss brought to the Flathead National Forest is one of two unique burners built by Air Burners, Inc, in partnership with the U.S. Forest Service. Part of the demonstration is a chance to run the CharBoss for several weeks and collect data on emissions, the net carbon cost of running the generator, and on the biomass burn rate. 

Page-Dumroese said her goal is for the Forest Service to have a similar mobile incinerator on hand in each forest or forest unit, adding another tool to a district manager’s toolkit. 

“Will one or two machines make much of a difference? Maybe not, but we can start people thinking about doing forestry in a different way,” she said. 

A biochar creation demonstration using a CharBoss mobile biochar air curtain burner in Coram on Feb. 16, 2023. Micah Drew | Flathead Beacon

Spotted Bear District Ranger Scott Snelson has integrated biochar into his forest-management practice for decades and is excited about the prospect of a larger mobile burner, especially if it means biochar evolving as an industry standard. Compared to the low-tech kilns Snelson’s used in the past, the CharBoss can process 15 times as much biomass. 

“I’m ready to put this machine through its paces,” Snelson said. “We normally can’t burn in the winter because of the emissions, which makes this a bit of a game changer. It’s a really big deal to be able to capture carbon and enhance the soil and that’s my motivation for bringing this here.”

Over the summer, Snelson plans to bring a Montana Conservation Corps crew onto the forest for firebreak and roadside burning, with kilns available to create biochar.

“We can have young folks learning about how they can provide a different carbon future for themselves, while aiding the forest,” he said. “That’s pretty exciting on its own.”

Biochar incinerators aren’t cheap — each CharBoss costs roughly $150,000 — but there are federal funds earmarked for further research and development. 

U.S. Sen. Jon Tester cosponsored a bill during the last congressional session that would establish a national biochar research network. The bill would have appropriated $250 million over five years for 20 research sites to study biochar in a range of settings to evaluate the technology’s benefits for soil health, crop production, carbon sequestration potential, climate mitigation and resource conservation. 

While that bill never passed through committee, in the Bipartisan Infrastructure Bill that Tester helped negotiate, an allocation of $200 million was included to remove flammable vegetation to produce biochar and other innovative wood products on federal lands.

“I want to get our hands on some of that funding,” Snelson said. “Whatever we can do to accelerate this practice toward industry standard is great. I think it’s easy to get excited about this kind of forestry work, and it’s a great chance to share that with the other industry folks.”

A biochar creation demonstration using a CharBoss mobile biochar air curtain burner in Coram on Feb. 16, 2023. Micah Drew | Flathead Beacon