January 18, 2022

Building blocks: Biochar provides multiple benefits

MIDDLETON, Wis. — A technology that features carbon sequestration and soil and environmental benefits was highlighted in a recent North American Ag Spotlight.

Jacek Chmielewski, BioMass Solution principal, discussed carbon reduction strategies using biochar produced by pyrolysis in the Dec. 21 webinar.

BioMass Solution’s mission is to bring financially and environmentally restorative and regenerative solutions to undervalued and problematic waste.

The firm provides a full scope of carbon negative solutions — feedstock selection, location selection, co-location and energy integration, carbon credits, biochar application and sales.

Chmielewski began looking at a process called pyrolysis in 2005 in collaboration with Iowa State University.

Pyrolysis is the thermo-chemical conversion of dry organic materials into bio-oil, syngas and biochar. Biochar is being promoted for its potential to improve soil properties, fertility and carbon sequestration in soil while also producing renewable energy.

“Scientists there were involved in turning agricultural waste in the U.S. Midwest such as corn stover or other byproducts of heavy corn production region into biochar through this pyrolysis process,” Chmielewski said.

“You basically heat up the biomass. You don’t burn it. You don’t combust it, but you fix the carbon by the process of heating, and it concentrates the carbon in this final product that’s called biochar. It looks like charcoal or a very dark substance, but it really has completely different characteristics.”

The pyrolysis process basically fixes the carbon dioxide that’s in the corn stover or other plant residue and creates fixed carbon, a non-reactive carbon. Biochar can then be used in many applications, one of the mains one being as a soil amendment.

“As part of a mix of soil amendment, let’s say you’ve got composted manure or a composted byproduct of agricultural origin and you would add some biochar to that and apply it to your soil because that carbon in the biochar is so fixed and so stable it has the ability to help rebuild carbon underground in the soil,” Chmielewski said.

“It starts building like a building block. There was a recent study that showed with one biochar application in a certain type of soil the amount of organic carbon underground in six years doubled without any further additions of the biochar because there was a better architecture or communication going on underneath the soil in terms of nutrients, microorganisms and any other activity.

“The roots and other parts of the plant that would die off would then be incorporated into that whole carbon architecture under the soil and help to rebuild carbon.

“The simple way to think about that is with pyrolysis we take the carbon dioxide in the air, we de-carbonize the air and then we re-carbonize the soil. We return it back to where it should really be because we’re intensely de-carbonizing not just in North America, but worldwide. It’s a huge problem that doesn’t get any press these days unless you’re in that space. Hardly anybody talks about soil de-carbonization — of soil extinction — and at the current rate of depletion that’s really going to be the result if we don’t change our ways.”

Reduces Nutrient Loss

Biochar will hold nitrogen, phosphorous and potassium and reduce the runoff into the water.

“That’s a really exciting application and we’re looking into that. I’m part subject matter expert/contributor to a program in Wisconsin — Agriculture Carbon Energy Water program — and biochar now is in the comment section as applicable to this program,” Chmielewski said.

“This especially true for dairy production and any kind of runoffs or any kind of manure that’s associated with that production and that includes runoff issues. In a lot of cases, even if a dairy farmer wanted to increase their production and if they want to be regenerative so they put in a digester, they make renewable natural gas, they offset natural gas, they might be limited by the permit because of the actual runoff limitations.

“So, if they can capture especially phosphorous and nitrogen, return that phosphorous and nitrogen and then have that nutrient work in a much more efficient way or have a much better selectivity because it’s held within the biochar in the soil much better. That will allow that farmer to potentially increase their production. So, it has a ripple effect.”

Carbon Credits

While the biochar product benefits the soil and environment, it also provides an opportunity to enter the carbon credit market.

“Depending where you are in the world, if you are able to get a pyrolyzer on your farm and produce biochar from (field) waste you can get into the market of biochar-based carbon credits. There are a number of companies worldwide doing this. Some of the primary ones are Puro.earth of Finland and Carbon Futures of Germany and then there are other exchanges developing for that,” Chmielewski said.

“There is a really robust and underserved market, so there is a lot more demand than there’s available credits based on biochar sequestration that the producer can monetize.”

NRCS Proposal

The U.S. Department of Agriculture’s Natural Resources Conservation Service Soil Health Program proposed Soil Carbon Amendment practice 808 which would allow farmers to receive cost-share funds for using biochar and compost to increase soil carbon.

Cost-share funds would be made available through the $1.8 billion Environmental Quality Incentives Program.

The proposed program is pending final approval and is currently in the comment process.

“This would not be a direct payment for implementing this, but perhaps a lowering of the operating cost would be to start incorporating biochar as part of their normal practice and as part of their strategy for crop rotation,” Chmielewski said.

“So, with time in the vast majority of cases the farmer would see a reduced need for synthetic fertilizer use. They would also see their water balance is improved because biochar through its really high surface area and ability to hold water helps with the water balance on the farm itself. And in situations when you might get into a long spell of really hot weather it provides you an extra insurance against drought.

“Those are things that are seen right now, but they’re not really defined in a monetizable way because every farm is going to be different, every soil is going to be different and every practice is going to be different. So, it’s a much more complex thing. But there’s a whole bunch of pull-through advantages associated with this, as well.”

Tom Doran

Tom Doran

Field Editor