Earth Pit Kiln

Fire in a pit – the start of an earth pit kiln. This would then be covered by layers and layers of fresh biomass that is allowed to char (“pyolyze”) but not burn to ash.

One of the simplest ways of turning biomass into charcoal is the “earth pit kiln”. It turns out that it also gives a very clean burn that allows for the production of high-quality biochar. It is less useful for making traditional charcoal. This is because most of the volatiles (gases, liquids, tars, etc. - basically, pyrolysis oil) are driven off and burned by this method and therefore lost from the energy content. In addition to char production, the heat generated in the pit kiln can be used for other products, such as pottery and other ceramics. These products may or may not be comparable in quality to those from a dedicated firing.

A similar type of pyrolysis is achieved by the more primitive Kon-Tiki Kiln.

Links

• Video: “Cone Pit Biochar in 15 minutes”
• “How to Make Biochar with Only a Match”
• “Biochar Burn Demonstration”
• BioEnergy Lists: “Earth Pit Kiln”
• (Mother Earth News) “Firing Pottery in a Pit Kiln”