Last fall, on a 1,000-acre family farm in Texas, a tractor drove through a cornfield pulling a shipping-container-sized machine behind it. In front, a mechanical harvester picked up cornstalks and other agricultural waste left behind after a recent harvest, chopping it into small pieces. Then the plant material went into the machine in the back, where it was heated to as high as 1,472 degrees Fahrenheit—and turned into biochar, a charcoal-like material that can help fight climate change.
Applied Carbon, the startup that developed the equipment, announced today that it raised a $21.5 million Series A round of funding to deploy a fleet of its biochar machines in states including Oklahoma, Arkansas, and Louisiana.
When crop waste sits in a field and decomposes, it releases greenhouse gases. But if the plants are turned into biochar, the carbon that the plants absorbed as they grew gets locked into place. The biochar can be added to fields to improve soil health and increase crop yields.
“When we turn biomass into biochar, we thermally convert the carbon from a fast-decomposing form into a stable, mineral form of carbon,” says Jason Aramburu, cofounder and CEO of Applied Carbon. “This mineral carbon takes much longer to break down in the soil—anywhere from hundreds to potentially millions of years depending on the quality of your process. At scale, we can sequester billions of tons of CO2 annually in the form of biochar.”
Biochar has a long history: In parts of the Amazon Basin, it has been added to soil to make it more fertile for more than 2,000 years. But the traditional way of making it—burning piles of wood that are covered so they have limited oxygen—releases a lot of CO2. Applied Carbon’s machine, a “pyrolyzer,” dries and heats up biomass inside a closed, low-oxygen chamber, creating both biochar and gas used to run the process. The conversion takes about two minutes.
Right now, most biochar is made from wood waste at energy plants near the coasts. “This method of producing biochar is problematic because it’s very expensive—wood has many other commercial uses,” says Aramburu. “It also requires moving tons and tons of material over hundreds or thousands of miles to farms in the heartland.” Because it’s hard to move, biochar is typically only used on high-value crops like organic vegetables or wine grapes.
There also isn’t enough wood waste to make a big dent in the climate challenge, he says. The company realized that using agricultural waste, like cornstalks or wheat straw, could be a better source. But that biomass couldn’t easily be run through existing machines. “We quite literally had to reinvent the pyrolyzer in order to efficiently convert these materials,” he says. Collecting it from fields to take to a central location was also challenging, so the team designed a mobile machine that could go to the field instead. The biochar that’s created can be used by the same farm.
For farmers, it means better performance: Studies show that biochar can increase crop yields by 16%. It also increases microbial activity in the soil, meaning it’s healthier. Farmers can use less fertilizer and less water.
Over the past two seasons, Applied Carbon has run trials with farmers growing corn, cotton, and peanuts in Texas, Arkansas, and Mississippi, testing how its approach compared to identical non-treated acres on the same farm. Crop yield, soil chemistry, and water retention improved as expected, Aramburu says. Farmers pay a fee per acre based on the projected yield increase and what they might otherwise spend to till their agricultural waste. (The company isn’t yet sharing the cost.) In some cases, state and federal funding is available. The startup also sells carbon credits for its carbon removal service.
If biochar were used on row crops globally, Aramburu says, studies suggest that it could potentially remove up to two billion metric tons of CO2 each year. “I believe this may be an underestimate, since it doesn’t take into account a production system like ours, that can harvest and unlock new sources of feedstock which were traditionally inaccessible or unprofitable,” he says.