Biochar: Too good to be true?

Agricultural residents and converted biochar

Would you like to curb or even reverse global warming? Help feed the world? Generate renewable energy?

Biochar is the answer, say its most fervent advocates.

If only life were so simple.

Biochar, alas, isn’t ready yet to be a meaningful solution to the climate crisis, or a way to enhance agricultural productivity at scale. But it’s an intriguing substance that has been around for thousands of years, and the production of biochar may prove to be one of the  technologies that governments and business deploy to deal with the threat of climate change. As, potentially, a carbon negative technology, it’s worth a look.

Biochar, for those of you who haven’t heard of it, is a charcoal-like substance that is created today by pyrolysis of biomass. In layman’s terms, biochar is made by taking organic material, like agricultural waste, heating it to very high temperatures, and allowing it to decompose in the absence of oxygen.

Jonah Levine

To learn about biochar, I met recently in Boulder, Colorado, with Jonah Levine, who is a co-owner of his own small biochar business and, until recently, was an executive with a startup called Biochar Engineering.   Jonah, who is 30 and lives near Boulder, got involved with biochar when a friend asked him to organize a conference on the technology in 2009 at the University of Colorado. A passionate environmentalist, he had previously worked as a wildlife biologist and as an engineer advising utilities on how to incorporate renewable energy into the grid.

Now he’s bullish on biochar.

“I feel like like I’m watching the beginning of an industry,” Jonah says. “Within a  decade, I feel this will be a functional business space.”

He told me that the history of biochar can be traced back to Brazil, where dark soils in the Amazon region are known as “Terra Preta.” No one can be certain about their origin, but some scientists believe they were created as long as 4,500 years ago, and that they helped support a complex, farm-based civilization in the Amazon, despite the region’s poor soil.

Johannes Lehmann, a leading biochar researcher at Cornell University, writes:

Terra preta research inspired the development of a revolutionary technology that can have tremendous impact on rural livelihoods as well as carbon sequestration. It builds on the application of stable organic matter in the form of bio-char (biomass-derived black carbon or charcoal) in conjunction with nutrient additions. This bio-char is very stable, provides and retains nutrients for millenia, as seen in Terra Preta.

As Jonah explained it to me, organic matter—crop waste, wood chips or even sewage—can be turned into biochar by heating the materials to between 300 and 900 degrees C. This generates a synthetic gas that can be converted into liquid fuels, used for  heating or generating electricity, as well as the biochar, which is then worked into soil to improve farm productivity. (The yield of products from pyrolysis varies with the temperature; lower temperatures produce more char, higher temperatures make more syngas.) Proponents claim that the biochar then sequesters carbon in the soil for hundreds to thousands of years—carbon that would otherwise be released into the air if the organic matter were burned or allowed to decompose.

Consider, for example, the vast swaths of pine trees being killed by mountain pine beetles in the Rocky Mountains. Some, I’m told, are being shipped to Europe to be burned as fuel in coal plants. Others are allowed to decompose, emitting CO2. If, instead, the dead trees were turned into biochar through pyrolysis, and the char was then used in agriculture, substantial amounts of CO2 emissions could be avoided even as renewable energy was created.

The business model for biochar is simple: Buy cheap organic waste, process it and then sell energy and biochar to create two streams of revenue. “If you have $150,000 and 90 days, I can sell you a piece of equipment that will make 50 to 100 pounds of char an hour,” Jonah told me. He says the process will also release about 2 million BTU per hour of producer gas.  “We need all the revenue streams we can get, including soil product value, energy value, carbon value, waste mitigation value and more,” he adds. The process, he assures me, requires far less energy than it generates, but the technology for making char isn’t well-developed yet.

James Lovelock, the British scientist who created the Gaia hypothesis, and prominent climate scientist James Hansen are biochar advocates. More than 500 academic papers have been written about biochar, Jonah told me, many of them focusing on its impact on agricultural yields. Research is going on all over the world, including at the USDA’s Agricultural Research Service and at an experimental farm in North Carolina. Here’s a global discussion list with lots of information on biochar research; another good source of information is the International Biochar Initiative, a Washington, D.C.-based nonprofit.

Various companies in Europe, Australia and the U.S. either sell biochar or biochar production units; all are small scale. One of the most intriguing is a startup based in Camarillo, California, called Cool Planet Biofuels that is developing “negative carbon fuels” with biochar as a byproduct. The company website says:

Imagine driving high performance cars and large family safe SUV’s while actually reversing global warming, and without using any foreign oil….the more Negative Carbon “N100″ fuel you use, the more carbon you permanently remove from the atmosphere.

It sounds too good to be true, but investors in Cool Planet Biofuels include Google Ventures, General Electric, NRG Energy and ConocoPhillips.

If they think biochar is worth their attention, it’s probably time for those of us concerned about the climate crisis to take it seriously, too.

[Biochar photo credit: Jonah Levine]


  1. says

    I cook daily on a twig-powered biochar-making stove. The ‘waste’ product goes into the compost bin then the veg bed. The veg seems to love it.

    Interesting to think how millions of households worldwide could do this, with fossil dependence, soil fertility, food production and indoor air quality all improving. With care it could reclaim barren land and reverse deforestation.

  2. Lewis E. Ward says

    So biochar is charcoal, based on the description. Making charcoal generates heat which was traditional a waste product. I’ll have to read more about this process-I’ve been hearing about the benefits to soils and the environment. James what’s the name of the twig stove you use? I also assume you can make one yourself.

    • says

      Yes charcoal is biochar when added to soil. Haven’t launched the name for my design yet but yes the key thing is that people can make it for themselves from used tins. This makes it cheap and also adaptable to people’s needs.

  3. Tiffany says

    Thanks for exposing the potential benefits of Biochar Marc. It wasn’t even on my radar until I read it today. I think the success of Biochar will come down to where those organic materials are sourced. Yes, Biochar is amazing and very sustainable when using discarded recycled materials. But beware of it becoming too ‘hot’ that any organic matter (such as healthy trees) are used as the materials to produce Biochar. Then, will the ends justify the means?

  4. says

    The Establishment of Soil Carbon as the Universal Measure of Sustainability.
    The Paleoclimate Record shows agricultural-geo-engineering is responsible for 2/3rds of our excess greenhouse gases. The unintended consequence, the flowering of our civilization. Our science has now fully realized the consequences of additional fossil emissions and has developed a more encompassing wisdom.

    Wise land management, afforestation and the thermal conversion of biomass can build back our soil carbon. Pyrolysis, Gasification and Hydro-Thermal Carbonization are known biofuel technologies,
    What is new are the concomitant benefits of biochars for Soil Carbon Sequestration; building soil biodiversity & nitrogen efficiency,
    for in situ remediation of toxic agents, as a feed supplement cutting the carbon foot print of livestock.
    Modern systems are closed-loop with no significant emissions. The general life cycle analysis is: every 1 ton of biomass yields 1/3 ton Biochar equal to 1 ton CO2e, plus biofuels equal to 1MWh exported electricity, so each energy cycle is 1/3 carbon negative.

    The Bio-refinery Technology to Harvest Carbon;
    The photosynthetic “capture” collectors are up and running all around us, the “storage” sink is in operation just under our feet, Thermal conversion reactors are the only infrastructure we need to build out.
    Carbon, as the center of life, has high value to recapitalize our soils. Yielding nutrient dense foods and Biofuels, Paying Premiums of pollution abatement and toxic remediation and the growing Dividends created by the increasing biomass of a thriving soil community.
    Since we have filled the air, filling the seas to full, soil is the only beneficial place left.
    Carbon to the Soil, the only ubiquitous and economic place to put it.
    Thank you for your efforts.

  5. says

    I’ve heard good things about biochar for several years now. I’d like for people to talk more about how to produce it at scale. Looks like some big players are looking into the scale question, which is good.

  6. says

    Nice comments — glad to see people making char at home — look for work on the “I-Can” by Jock Gill for DIY home tin stuff. Look at “All Power Labs” for energy related DIY equipment. And of course check out what “Biochar Solutions Inc” is doing for larger (but still distributed) biochar technology- Wood products and Green house partners may like what Biochar Solutions is doing.

    Biochar can be done on many scales for lots of interests from energy to carbon to farming or gardening—- lots of interesting stuff.

    Jonah Levine

  7. says

    Thanks for this nice look at biochar and its potential, Marc (having just come across it). There are several studies taking place in the Chicago area examining whether biochar could be useful in urban soils, particularly if it might benefit street trees, which struggle with a host of difficult growing conditions.

    (A note about the photo caption above, should that be “Agricultural residue and converted biochar”?)

  8. Bill says

    Check out Gary Gilmore’s charcoal gasifier. It generates producer gas, which fuels an engine, by gasifying charcoal. It could easily fuel a generator, which would charge a home battery bank. It’s inexpensive to build, clean burning, and can be done at the home user level.
    No reason the waste heat generated couldn’t be used to make another batch of biochar while it runs the generator, and maybe heat hot water for the home, all at the same time.

    Imagine what could be done on an industrial level if We-The-People insisted on it.

    Also, research is going on to establish the feasibility of converting human waste to biochar. Talk about a consistent, dependable feedstock! That biochar would work just fine as a soil amendment, killing 2 birds at once; waste elimination and agricultural needs. Best part is a portion of the biochar produced could be used as the energy source to produce more. All from a waste product of society most think of as a worthless material to be discarded. This could go a long way toward food security (building of farming land) in developing nations, as well, since humans eliminate waste from their bodies no matter where they live, not to mention how quickly sanitation would improve if human waste became a commodity. And, biochar can be an important component of water filtration, which is also a problem in developing nations.

    This technology needs to become known by more people until it becomes common knowledge. Once enough people know about biochar and what it can do to help our environmental situation, folks will insist it be used to reverse the damage done to this planet.

  9. Brian Barackman says

    I just became aware of Biochar and I was wondering what happens to the carbons? Do the Microbacteria consume carbon? Does it get put into are crops? At a certain threshold does it get released back into the atmosphere? Has there been studies conducted of terra pretta to see wether it is immiting carbon? Another concern I have is if the whole planet gets into biochar and off fossil fuels could this drop the global temps and send us into an ice age in 50 years? Thanks Marc I’m in boulder and just put in a bid to reclamate a site in summit county using biochar if you could forward my contact info to Jonah levine that would be great I would love to talk with him. thanks again


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>