How Biochar Is Produced
Biochar production is an ancient technology with a very modern twist. Ancient users of biochar-like substances such as terra preta made them by setting large piles of wood products on fire. Then they smothered the flames once the fire got hot and allowed charcoal to form in the resulting reduced-oxygen environment.
This process remains one of the most common ways non-industrial charcoal is made today. However, modern day biochar can be produced in a wide variety of production units ranging from very simple pit fires to very complex bio-refineries.
The more complex the unit, the more control one has over the amount of biochar produced relative to other byproducts like synfuels and heat.
All biochar production units have one thing in common: the breakdown of carbon containing material by heat in an oxygen-reduced atmosphere. This process is called pyrolysis.
As the material is broken down, by begin heated during pyrolysis, it releases gases containing hydrogen. These gases can be combusted to continue driving the reaction forward. So making biochar does not consume energy.
Figure 1 shows a simplified diagram of how biomass is turned into biochar.
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Figure 1: Biomass is heated in a reduced oxygen environment to produce biochar, synfuels (gas & oil) and heat. Gaphic Source: Biochar, climate change and soil: A review to guide future research (CSIRO) |
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Figures 2 and 3 show medium sized biochar pyrolysis units currently being used on farms.
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Figure 2: This poultry manure pyrolysis unit produces heat and biochar
Photo Source: http://www.biochar-international.org/technology/production |
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Figure 3: This BEST Energies pyrolysis unit produces biochar
and generates electricity from the resulting syn-gas.
Phoro Source: http://www.biochar-international.org/technology/production |
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Interest in home-based biochar units is very high, and many people are experimenting with do-it-yourself units. While these units can be effective in producing biochar, they are frequently inefficient in trapping and using the resulting synfuels.
And some of the DYI oil drum units appear to be polluting. For this reason, we urge you to start your use of biochar with commercially available biochar. Please click this link for the most reputable sources of commercial biochar.
We'll also keep you abreast on the same page of the latest developments in commercially available backyard biochar pyrolysis units and on non-polluting DYI units as they become available.
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