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Biochar’s Potential to Help is Rich, but Hurdles Remain

To hear some of its proponents talk, the substance known as biochar — a form of charcoal made from logging and agricultural waste — has properties that verge on the magical. It not only cuts down dramatically on the carbon emissions that cause global warming; it also has the potential to create millions of jobs, and helps soil retain nutrients and water to make crops grow bigger and stronger. You almost expect to hear the words “Just $19.99 plus shipping and handling! Operators are standing by!”

The truth, as usual, is a bit less extravagant.

“Biochar not going to solve all of our problems,” said James Amonette, a soil chemist with the Department of Energy’s Pacific Northwest National Laboratory, in Richland, Wash. “But I think it’s a positive thing in terms of soil fertility, especially in the tropics. And it does have the added benefit of sequestering carbon.” 

Credit: Kim Conan

How much carbon is a matter of dispute, but in a 2010 article in Nature Communications, Amonette and several co-authors estimate it could reduce carbon emissions by as much as 10-12 percent. That’s not enough to save the planet, but a healthy start at fighting off climate change.

The way biochar achieves all of these remarkable goals is actually quite straightforward. Farming, tree-clearing and plain old daily living create uncounted tons of waste every year. Burn it and you pump carbon dioxide into the air to warm the planet. Let it rot and the same thing happens, only a bit more slowly. If you heat it in container where there’s no oxygen, however — a process known as pyrolysis — you make charcoal. 

The charcoal, or biochar, is far more stable than the original wood or rice straw or cornstalks, especially if you plow it underground; depending on what it’s made from, it can last for hundreds or even thousands of years without rotting. “That,” Amonette said, “accounts for about half of its carbon-reduction power.”

Another 25 percent, he said, comes from the energy released in the biochar-making process. If you capture and use that energy, you’re cutting down on energy you’d have to get from some other source. And the last 25 percent comes from biochar’s effect on the soil itself. “Some studies show reductions in emissions of methane and nitrogen oxide that come from untreated soil,” said Johannes Lehmann, a soil scientist at Cornell.

“There’s also some indication that soil-borne diseases are reduced, so you need less herbicide, but these have to be firmed up,” Lehmann said.

Finally, biochar’s absorbent qualities help soil retain moisture, which is especially valuable in places where drought is common. In the Amazon basin, a kind of biochar-rich soil known as terra preta — made either deliberately or accidentally by indigenous people — is still more fertile than surrounding land more than a thousand years after it was created, according to Lehman.

All of this being the case, it may seem odd that biochar isn’t a big part of the international conversation about staving off climate change. But despite its great promise, biochar isn’t quite ready for prime time. For one thing, the more waste you turn into biochar, the less you can turn into biofuels, and biofuels have a lot of proponents, too.

For another, biochar works much better as a soil improver where the soil is poor to start with. “If you add it to an acid soil, like those in the tropics,” Amonette said, “you can improve productivity two to threefold. If you add it to Iowa soil, it makes no difference at all.”

Finally, scientists still don’t have a good handle on what the best feedstocks for biochar might be. Organic waste comes in all different varieties, and some might well have less of biochar’s stellar qualities than others.

That suggests a need for a lot more experimentation, but unfortunately, Amonette said, “there isn’t exactly a gold rush of funding.” 

It’s a chicken-and-egg problem, he believes. Without the research, it isn’t obvious that biochar can live up to all of its promise (even his own seminal 2010 paper presented a mostly circumstantial case). And without a guaranteed benefit, funding agencies are loath to put too much into research.

“In this country, the U.S. Department of Agriculture is putting some money into it, but that’s about it,” Amonette said.

The greatest promise for understanding biochar comes overseas: Amonette will be spending the second half of September at an international biochar conference in Beijing. “The Chinese,” he said, “are extremely interested.”


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By prokaryotes (Berlin, Germany)
on September 18th, 2012

The Secret of El Dorado (The discovery of Biochar)

Incredible story about the discovery of biochar, from a decade ago…

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By Erich J. Knight (Mc Gaheysville, VA, 22840)
on September 18th, 2012

Big Eggs Quickly solve the chicken-and-egg problem.

I landed the opening speakers slot at the third US Biochar conference, 2012 Sonoma Biochar Conference 2012 US Biochar Conference | Building Soil - Redirecting Carbon

My talk and slides are actually listed as the closing session, with no projector at the outdoor opening ceremony. It focuses on closing the nutrient loop on the farm with char/compost and Biochar Feed rations for livestock and Aquaculture.
“Carbon Conservation for Home, Health, Energy & Climate” (bellow)

If you are tantalized by the Biochar platform for biofuels, the cutting edge Big dog, Elephant in the room, at the Sonoma Biochar conference was CoolPlanet Energy Systems. In a nutshell,  they have such control over carbon bonding in their thermal conversion process, they can squeeze out 75 gallons of bio- gasoline and 1/3 ton of Biochar from one ton of biomass.Their tag line; “The more you Drive. The Cleaner the Atmosphere”. They state their production cost at $1.25/gallon, they turn a dial and can produce $2/gallon jet fuel. I can hear you saying this is too good to be true, however Google, GE, BP and Conoco believe it is true.
CoolPlanet Biofuel’s CEO Explains his energy cycle:

This all leaves me very optimistic, for the CEO and Google share the same ethos, farm scale skid mounted reactors will be the first to production next year. This farmer friendly, scalable reactor, they plan to deploy at the village scale in the Third World and at the farmer scale here.

I believe this technology will allow the American public to have their carbon free energy lunch without paying a premium for it.


Erich J. Knight
Shenandoah Gardens

Opening Speaker for the 2012 USBI Biochar Conference;
2012 US Biochar Conference | Building Soil - Redirecting Carbon

With great implications for even higher values for Biochar soils;
Potassium centered Aerosols, as cloud nucleation catalyst, another ecological service delivered by the fungal kingdom.
The Rainmaker of all rain makers. Now we know what March conspires, to call April showers, that bring the May flowers.
How Fungi May Create the Amazon’s Clouds

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By Ronal Larson (Golden, Colorado 80401)
on September 19th, 2012

  There is a new means of making biochar that seems certain to solve several of the correctly stated past limitations on Biochar progress..  See the website www,, and especially a short video there emphasizing.a future “N=100” fuel (equal parts carbon neutrality and negativity).  Very small amount of CO2 release in producing the “drop-in gasoline” - and charcoal naturally appears as a co-product.  Jim Amonette has been conservative in listing a few of the benefits.  It also appears that less pumping is needed for irrigation water.  The added above ground biomass can go on for centuries and most analyses stop at five or ten years (and often less).  There is also greater below-ground biomass.  How much land will eventually be converted to combined energy/biochar plantations will depend on our waking up to the disaster we face if we don’t get back to 350 ppm (or less).

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By Amber Tribble (Everson, WA, 98247)
on March 27th, 2013

Wow!  I appreciate all the dialogue here, and although as stated biochar may not be ready for primetime, I think we are approaching a place where it is becoming much more recognized by environmental engineers - particularly with water remediation projects.  There is a youth movement behind it too, young green business people getting the word out and lots of research to support all of the soil and plant benefits.  Of note, we are proud to say at Biochar Supreme, we have become the first in the State of Washington to become organically certified, and it appears that has drawn in a lot more support from the tilth farmers etc.  Looking forward to seeing us burying as much carbon as possible!—Amber

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By Deena (lincoln, calif 95648)
on March 28th, 2013

would like ideas on how to build stove from metal barrells for compost burning

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