By Barbara Hirsch
In the past several years, this stuff called biochar has been seen as a potential planet changing product, providing ways of simultaneously mitigating climate change, cleaning the air, generating energy and managing waste. It does sounds like a game changer, eh?
Biochar is an un-manufactured form of charcoal. It is created by very slow burning of biomass in a low oxygen environment – pyrolysis – creating a charred substance that contains about half the carbon that was in the original material. The other half is emitted in the burning process, and can be used as fuel. The story goes that if left to rot, or simply burned, the biomass would release its carbon into the atmosphere, but as biochar it sequesters a large part of its carbon, indefinitely. In fact it (terra preta) remains deep in the soil of ancient civilizations.
Some research has shown that when applied to fields, biochar boosts agricultural yields by increasing microbial activity, retaining nutrients and water. And the making of it, using agricultural waste or almost anything organic that is handy, also produces fuel as heat or syngas, to be used in place of fossil fuels. A devoted researcher describes 55 uses for the stuff here.
A microcosm of this system can be seen in a modern but simple cook stove, that could greatly improve the lives of three billion people who cook their food on open fires, often suffering health problems from the spewing smoke. With it they could use much less valuable fuel, breathe no smoke and sell the biochar they make while cooking!
Back in the U.S., Kingsford charcoal is owned by Clorox (few things are as black and white) and their charcoal production, although energy intensive, employs the heat from the charring as energy for a later part of the process. Of course the charcoal then goes on to emit its carbon, as the grills nourish and entertain us for the summer barbecue season