What is Biochar
What Is Biochar
Remove carbon dioxide from the atmosphere by sequestering it in charcoal
carbon | biomassIn our article on
carbon capture and storage we looked at how carbon dioxide emissions from power stations can be reduced if we capture the gas and store it under the ground. Unfortunately this process is very expensive.
Trees do an excellent job of removing
carbon dioxide from the atmosphere, but when they are burned or rot down at the end of their lives, the gas is released straight back into the atmosphere - the
carbon cycle.
Charcoal = Biochar
If wood is partially burned in an oxygen-poor environment it turns into
charcoal - virtually pure carbon, and chemically very
stable. Unburnt charcoal is therefore a
carbon sink potentially holding carbon for hundreds or thousands of years and reducing the overall concentration of carbon dioxide in the atmosphere.
When charcoal is made for this purpose it is called
biochar. A side-benefit of biochar is that it can be dug into soils to
increase agricultural yields and to improve soil fertility (as explained below). Making charcoal is a very cheap and simple process whereas removing carbon from power station emissions is expensive and complicated. By making
biochar in poor tropical regions, it offers local farmers a chance to earn a living, and for local agricultural land to be improved.
Terra Preta
Terra preta is portuguese for
dark soil. In the Amazon basin in Brazil there are regions where the soil is very dark thanks to carbon (charcoal) concentrations two to three times higher than found elsewhere. These soils are famed for their
high fertility.
Currently the reason for the increased
fertility of the
terra preta is not fully understood, but it is believed that the porous sponge-like structure of charcoal (i.e. the thousands of tiny holes throughout each piece of charcoal as pictured above under a microscope) gives a huge surface area onto which
nutrients can adhere, and beneficial
micro-organisms can cling thereby improving the quality of the soil over time - i.e. the charcoal acts as a
catalyst for soil improvement.
Biochar can also be laced with elements such as potassium to increase the rate of soil improvement when it is dug into the ground.
Making Biochar on an Industrial Scale
NEW Click here to view our new article
Microwaves for Industrial Scale Biochar which introduces
Carbonscape, a company which has launched a commercial biochar producing
microwave oven which can
fix one tonne of carbon dioxide per day at a cost of around $65.
Article Last Modified: 16:30, 17th Mar 2009Comment on this Article
If you have any comments on this article, please email them to
neil@reuk.co.uk.
Recommended Related Articles
People who read this article also enjoyed the following articles:
Microwaves for Industrial Scale BiocharRead how giant microwave ovens could be used to make biochar and lock away carbon
Article Last Modified: 16:30, 17th Mar 2009carbon | news
|
|
|
