The artists at All Power Labs took a skillset for building large kinetic sculptures for the Burning Man celebration and converted it to producing independent, low carbon power. While the rest of society may be content to wait for the oil to run out before they start thinking about alternatives, All Power Labs kicked into gear when the city cut off their electricity for building code violations ten years ago. Spark plug Jim Mason responded by jumping into gasifier development and construction, chipping up old shipping pallets and construction waste to keep the lights on and the artists working.
Chief Scientist Bear Kaufman with the GEK Power Pallet -- a 10kw generator powered by wood chips. The only emissions are the exhaust from the gas burning in the 18 hp Kubota engine.
The basic technology to gasify wood was developed during WWII by individuals who wanted to keep driving in the face of gasoline rationing, but it was always a finicky process, dependent on the time-consuming preparation of fuel into dry, one inch cubes of wood. What Jim Mason and his crew of Steampunks and Burners have done is to optimize the recovery of thermal energy -- producing a gasifier that runs on plain woodchips.
Using 21st century desktop manufacturing technologies like a computer guided plasma cutter, they perform what Mason calls "DIY power hacking." Computer modeling of combustion processes remains such a complex problem, that it is faster and easier to just cut new parts out of metal and try them in fast build and test cycles. The design advances quickly because all the information is open source, and anyone can participate and offer improvements. People can be authors of their own power systems similar to the way that desktop publishing and the Internet created the information revolution.
All Power Labs now sells what it calls the "Gasifier Experimenters Kit" or GEK. They also offer a Biochar Experimenters Kit -- biochar is a natural byproduct of gasification. On 10-10-10, about 50 GEK and BEK customers were on hand for a workshop to gain hands-on experience in construction, testing and modification of the machines. One part of the crew had stayed up until 2:30am the night before making two kinds of biochar that would be tested in a nearby community garden.
Biochar is a charcoal-based soil amendment that can dramatically increase plant growth. Biochar also sequesters carbon because plants absorb carbon dioxide from the atmosphere as they grow. If you burn a plant or let it rot or compost, all the CO2 returns to the atmosphere. But if you bake it and burn only the gas that comes out of it, you are left with charcoal that lasts for hundreds to thousands of years without breaking down, effectively sequestering carbon from the atmosphere.
Jim Fournier, CEO of Biochar Engineering Corporation, told the 10-10-10 work party that biochar is one of the only ways we have to actually remove carbon from the atmosphere and soon we are going to feel a lot of urgency to do that. Events like the floods in Pakistan, fires in Russian and the recent extreme heat in Los Angeles are just a taste of what's in store for us. Historically, our atmosphere has had less than 300ppm of CO2. We may go to 450ppm or higher before we are able to get off of coal and oil. Because it takes about 100 years for natural processes to remove CO2 from the atmosphere, we have to find ways to help nature along. Biochar is one of those ways.
Fournier said that one ppm of atmospheric CO2 is roughly equivalent to 3 gigatons (Gt) of carbon and that biochar could remove at most 2 Gt per year. So even with help from biochar, we can only remove about a half of a ppm of CO2 from our atmosphere annually. We have dug ourselves into a very deep hole. It is past time to grab shovels and start digging ourselves back out.
On the morning of 10-10-10 we delivered two barrels of biochar to the community garden. I described my own experiments with biochar and cautioned the gardeners that because fresh biochar can act like raw compost, in the first year after adding biochar to soil it is important to add plenty of nitrogen as well -- urine being my preferred source. Immediately someone produced a stack of drink cups, and we all trooped off to the bathroom to fill the cups with liquid gold in true DIY spirit.
Kelpie Wilson works as the Communications Editor for the International Biochar Initiative, a non-profit organization that supports the community of people working to implement biochar systems.
The basic technology to gasify wood was developed during WWII by individuals who wanted to keep driving in the face of gasoline rationing, but it was always a finicky process, dependent on the time-consuming preparation of fuel into dry, one inch cubes of wood. What Jim Mason and his crew of Steampunks and Burners have done is to optimize the recovery of thermal energy -- producing a gasifier that runs on plain woodchips.
Using 21st century desktop manufacturing technologies like a computer guided plasma cutter, they perform what Mason calls "DIY power hacking." Computer modeling of combustion processes remains such a complex problem, that it is faster and easier to just cut new parts out of metal and try them in fast build and test cycles. The design advances quickly because all the information is open source, and anyone can participate and offer improvements. People can be authors of their own power systems similar to the way that desktop publishing and the Internet created the information revolution.
All Power Labs now sells what it calls the "Gasifier Experimenters Kit" or GEK. They also offer a Biochar Experimenters Kit -- biochar is a natural byproduct of gasification. On 10-10-10, about 50 GEK and BEK customers were on hand for a workshop to gain hands-on experience in construction, testing and modification of the machines. One part of the crew had stayed up until 2:30am the night before making two kinds of biochar that would be tested in a nearby community garden.
Biochar is a charcoal-based soil amendment that can dramatically increase plant growth. Biochar also sequesters carbon because plants absorb carbon dioxide from the atmosphere as they grow. If you burn a plant or let it rot or compost, all the CO2 returns to the atmosphere. But if you bake it and burn only the gas that comes out of it, you are left with charcoal that lasts for hundreds to thousands of years without breaking down, effectively sequestering carbon from the atmosphere.
Jim Fournier, CEO of Biochar Engineering Corporation, told the 10-10-10 work party that biochar is one of the only ways we have to actually remove carbon from the atmosphere and soon we are going to feel a lot of urgency to do that. Events like the floods in Pakistan, fires in Russian and the recent extreme heat in Los Angeles are just a taste of what's in store for us. Historically, our atmosphere has had less than 300ppm of CO2. We may go to 450ppm or higher before we are able to get off of coal and oil. Because it takes about 100 years for natural processes to remove CO2 from the atmosphere, we have to find ways to help nature along. Biochar is one of those ways.
Fournier said that one ppm of atmospheric CO2 is roughly equivalent to 3 gigatons (Gt) of carbon and that biochar could remove at most 2 Gt per year. So even with help from biochar, we can only remove about a half of a ppm of CO2 from our atmosphere annually. We have dug ourselves into a very deep hole. It is past time to grab shovels and start digging ourselves back out.
On the morning of 10-10-10 we delivered two barrels of biochar to the community garden. I described my own experiments with biochar and cautioned the gardeners that because fresh biochar can act like raw compost, in the first year after adding biochar to soil it is important to add plenty of nitrogen as well -- urine being my preferred source. Immediately someone produced a stack of drink cups, and we all trooped off to the bathroom to fill the cups with liquid gold in true DIY spirit.
Kelpie Wilson works as the Communications Editor for the International Biochar Initiative, a non-profit organization that supports the community of people working to implement biochar systems.
Lee Reese (left) listens as Paul Wever talks about a biomass gasifier during a tour of Freedom Field at the Rock River Reclamation District for International Bioenergy Days on Wednesday, Sept. 29, 2010.
An ancient crop in the new world
A seedling grown in a potting mixture including Biochar. Cornell University scientist Johannes Lehmann thinks biochar is crucial way to reduce human carbon emissions, by burying them. Photograph: www.biochar-international.org
Win-win solutions can be hard to come by. But if Cornell University soil scientist Johannes Lehmann is right, there may be a way to lower our emission of heat-trapping greenhouse gases, save millions of people's lives, and significantly boost the productivity of the world's farms—all at the same time. And, most remarkably, his strategy is based on a deceptively simple technology invented 8,000 years ago.
Lehmann's idea starts with organic leftovers that people normally burn or leave to rot—forest brush, corn husks, nutshells, and even chicken manure. When this stuff decays or goes up in smoke, it releases vast amounts of heat-trapping carbon into the atmosphere. Lehmann's plan is to short-circuit this carbon cycle by creating a material called biochar. Making biochar involves heating this organic matter without oxygen in a process called pyrolysis. It can be carried out in a small household stove, or it can be an industrial operation. Either way, the pyrolysis doesn't produce carbon dioxide as ordinary, oxygen-fueled fire does. Instead, the carbon gets locked up in black chunks of charcoal-like matter.
Take that biochar and bury it in farm fields, and it acts like a giant carbon sponge holding in moisture and nutrients that boost crop yields. In 2003, Lehmann and his colleagues treated farm fields in Colombia with biochar and found they yielded up to 140 percent more corn per acre compared to biochar-free fields.
What's more, the buried biochar turns out to be remarkably stable, locking up carbon for hundreds or even thousands of years. Lehmann's calculations suggest that transforming the crop waste from 120 million hectares of U.S. farmland alone could sequester ten percent of the nation's annual carbon emissions. Play that out on a global scale, and you can make a serious dent in climate change.
Lehmann's fascination with biochar began in the late 1990s while he was living in Brazil, working on a project to heal the ravaged soil of the rainforest. When the forest is cut away and replaced by farms or ranches, the fragile Amazon soil erodes and eventually becomes exhausted. As Lehmann toured the Amazon, he would sometimes come across huge patches of rich, dark soil that stood out from the red clay common to the region. When he traveled by boat, he could see thick layers of the stuff sandwiched along the banks.
Lehmann was looking at one of the Amazon's great mysteries: terra preta, or black earth. He wasn't the first to encounter this amazing soil. Europeans first recorded pockets of terra preta along the waterways of Brazil in 1871. But even after more than 100 years, no one was quite sure how it had gotten there or why it worked.
Early on, some scientists speculated that terra preta was the remnants of dead lakes. Others thought it was formed by blankets of ash from volcanoes. It didn't occur to scientists for a long time that terra preta might be the signature of an ancient Amazonian society. They narrowly pictured the Amazon rainforest as a primeval wilderness before the arrival of Europeans. In recent decades, however, archaeologists have recognized that pre-Columbian Amazonia supported a prospering population of Indians who built towns and large-scale farming and fishing operations.
Thanks to the work of Lehmann and others, it now seems clear that those ancient farmers were onto something. Whether deliberately or by happy accident, the Amazonians created terra preta and used it to improve the soil. Radiocarbon dating reveals that people began laying down the stuff at least 8,000 years ago. And they kept creating more of it until Europeans arrived. For thousands of years, it steadfastly resisted erosion and remained loaded with rich, black carbon.
And this discovery led to a profound idea. Lehmann and his colleagues began to wonder whether they could create a modern-day terra preta—in the form of biochar—to solve some very twenty-first century problems.
For the past decade, Lehmann has been devoted to finding the answer. His work is spread out across multiple fronts. He oversees experimental farm fields in countries including Brazil, Colombia, and Kenya as well as greenhouse and laboratory experiments at Cornell University in Ithaca, New York. He's currently evaluating the horticultural effects of over 100 different biochar variations—ranging from chicken manure to nutshells and even discarded food waste from university cafeterias.
Lehmann thinks that large-scale biochar production in the U.S. and other industrialized countries could be an efficient way to combat global warming. In a commentary in Nature, Lehmann proposed the idea of power plants fueled with materials such as forest residues or fast-growing plants such as switch grass growing on idle land. (1) A number of companies already generate bioenergy in this way. But to date, they've treated biochar as merely a byproduct that can be burned to reduce costs. Lehmann believes that, if they were to put biochar back into the soil instead of burning it, bioenergy could be a carbon-negative industry.
To provide a sense of scale potential, Lehmann has made some preliminary calculations using U.S. land figures. Pyrolysis of forest residues from 200 hectares of timberland, pyrolysis of crop residues from 120 million hectares of farmland, and pyrolysis of fast-growing vegetation from another 30 million hectares of idle cropland could each sequester about ten percent of U.S. annual fossil-fuel emissions.
But Lehmann believes that biochar production can also work on much smaller scales in the developing world to save lives and reduce carbon emissions. In many parts of the world, people are wiping out forests to make charcoal for fuel. When they cook with charcoal, they often use poorly designed indoor stoves that fill their houses with a deadly cloud of pollutants. (Indoor air pollution kills 1.6 million people every year.) Moreover, when wood burns in an ordinary stove, it releases soot and carbon dioxide, both of which can trap heat in the atmosphere.
Biochar stoves could potentially knock out both threats with one proverbial stone. Several inventors are designing cheap, efficient models that allow people to cook without generating a lot of smoke. Instead of heating wood, these stoves use other plant material—even run-of-the-mill farm refuse. "Rather than women having to trudge into the forest and bring out a big log, they can use brush or corn husks," says Lehmann. They simply load the stove with fresh organic matter and light a conventional fire just long enough to get the material hot enough to release gases, which the stove can then burn to release even more heat.
It takes conventional wood fire only a few minutes to get pyrolysis into a self-sustaining cycle. And because a pyrolysis stove doesn't produce much smoke, it releases very little carbon dioxide or soot. Instead, the carbon ends up in leftover lumps of biochar. And when farmers bury it in their fields, that carbon stays underground—for an extraordinarily
long time.
It's the kind of win-win that captures people's imaginations. Thanks to Lehmann and his fellow biochar advocates, terra preta has been transformed from obscure patches of Amazonian dirt to the subject of some of the biggest debates in climate-policy circles. The U.S. Department of Agriculture and other funding agencies are plowing millions of dollars into biochar research. Private companies are starting up, hoping to make money in the carbon-credit market by producing biochar on an industrial scale.
Mario Molina, Nobel laureate for his discovery of the destruction of the ozone layer, and his colleagues published a paper in Proceedings of the National Academies of Sciences last fall in which they argued in favor of solutions for climate change that would be both quick and effective. (2) Biochar was high on their list. "These and other fast-action strategies may reduce the risk of abrupt climate change in the next few decades by complementing cuts in CO2 emissions," the scientists wrote.
But the Royal Society came to a notably different conclusion about biochar in their report Geoengineering the Climate. (3) They questioned how effective biochar would turn out to be for reducing carbon emissions. They also warned that the global biochar bonanza could even cause great harm. "Inappropriately applied incentives to encourage biochar might increase the cost and reduce the availability of food crops," they wrote.
Writing in The Guardian, environmentalist George Monbiot made a blunter political attack on biochar. (4) "The idea that biochar is a universal solution that can be safely deployed on a vast scale is as misguided as Mao Zedong's Great Leap Backwards," he wrote. "We clutch at straws (and other biomass) in our desperation to believe there is an easy way out."
Lehmann is not a Maoist zealot about biochar, however. He is the first to admit that biochar might not make sense in many parts of the world—and that meeting the challenges of global warming will require significant reductions in fossil-fuel use. But he's also a realist. He insists that any viable climate-change strategy must also involve actively withdrawing some carbon dioxide from the atmosphere. And if we have to stash away large amounts of carbon to create temporary relief in our emission balance—why not grow some food with it?
Literature Cited
1. Lehmann, J. 2007. A handful of carbon. Nature doi:10.1038/447143a.
2. Molina, M. et al. 2009. Tipping elements in Earth systems special feature: Reducing abrupt climate change risk using the Montreal Protocol and other regulatory actions to complement cuts in CO2 emissions. Proceedings of the National Academy of Sciences, doi:10.1073/pnas.0902568106.
3. The Royal Society. 2009. Geoengineering the climate: Science, governance and uncertainty. The Royal Society Policy document.
4. Monbiot, G. 2009. Woodchips with everything. It's the Atkins plan of the low-carbon world. The Guardian, 24 March 2009.
• Carl Zimmer is a contributing editor at Discover magazine. His latest book, The Tangled Bank: An Introduction to Evolution, was published by Roberts and Company Publishers in 2009. He also contributes articles to the New York Times, National Geographic, Time, Scientific American, Science, and Popular Science.
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