Biochar 101

Photo: alextiller/Flickr

Though you may not have heard of biochar, it's a good bet you'd recognize it if you saw it.

 

Biochar is just charcoal. It's created when organic matter like wood chips, rice stalks or even manure is heated up in the absence of oxygen --think of a sealed metal drum full of wood chips over a fire. It's simple, can be produced anywhere and could just end up saving the world.

 

For something as simple as charcoal, biochar -- in the right applications -- does three pretty amazing things: It takes carbon dioxide out of the atmosphere and locks it into a solid form, improves the health of soil it's plowed into, and creates clean energy.

 

When organic matter is turned into biochar, the CO2 contained within the plant is converted into solid carbon. Plowing biochar into soil sequesters the carbon for a long time -- biochar fields have been found in South America dating back thousands of years and still full of their carbon solids. Soils augmented with biochar retain nutrients better as the tiny, spongelike structure of the carbon solids sucks up and holds the fertilizer, reducing the amount needed. The same structure holds water better and has been shown to decrease the emissions of nitrous oxide and methane into the air from the soil.

 

When former slash-and-burn farmers in the rain forests of South America adopt slash-and-char techniques, they're able to stay on and farm the same plot of land year after year instead of having to move on every couple of seasons when the soil becomes depleted. Their path through the rainforest is halted, saving countless acres. The farmers are able to produce a lot more food on the healthier soil and can improve and invest in their land and infrastructure.

 

When organic matter is heated up in the absence of oxygen, it releases hot gases that can be captured and burned in power generators, or also refined into bio-oil and syngas, both which can be further refined into effective gasoline and diesel substitutes. If the gases are burned right away, the process of creating biochar — called pyrolysis — is energy-positive, returning six to nine times as much energy as necessary to run and maintain it.

 

Right now we're far from squeezing out all the benefits biochar offers. Sustenance-based slash-and-burn farmers still must switch to slash-and-char, and we need to build the infrastructure for taking in agricultural waste from farms and then distributing the resulting biochar back to their fields. One of the great things about biochar is how easy it is to make. Poor farmers can make it using simple, handmade clay kilns, while rich farmers can build elaborate biochar processing plants that also generate electricity, bio-oil and syngas.

 

Biochar is an easy sell. Everyone involved in the process wins. Poor farmers get more food for their work and are able to settle on one plot of ever-productive soil. Rich farmers and corporate agriculture save a lot of money on fertilizer and also see the same boost in production. The environment benefits because of the reduction in fertilizer runoff and the removal of CO2 from the air. Big business wins because of the profits generated from the production and distribution of biochar. Politicians get to take credit for implementing a pragmatic, job-creating solution to global warming. Workers get jobs. Governments get tax revenue.

 

The Obama administration seems to be a budding friend of biochar. Interior Secretary Ken Salazar, while still a U.S. senator from Colorado, introduced the Salazar Harvesting Energy Act of 2007 that would have provided $30 million to help farmers buy pyrolysis systems. Though his act ultimately failed to pass, Salazar is on record as being in favor of pyrolysis and the widespread adoption of biochar. In a recent interview, President Obama spoke out in favor of a plan floated by food-policy guru Michael Pollan that decouples our agricultural from a dependence on cheap fossil fuels and a monocultural corn-based focus. Our government is primed for biochar.

 

Obama has made it clear science will get its seat back at the table of power after eight years of being on the fringes, something that bodes well for the scientifically vetted biochar. An effective deployment of biochar could solve problems in energy production, global warming prevention, job creation and food security, in both price and availability.

 

For more information on biochar, check out these links:

• International Biochar Initiative

• Gardening with Biochar

• Biochar.org

• Biochar for Environmental Management: Science and Technology

 

 

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