A Charcoal Experiment
History
Charcoal is basically wood that has been "cooked" to remove water and other volatile components that hinder the combustion of it carbon molecules. The result of the charcoaling process is a light, black, porous material that burns hotter than dry wood.
Human civilization has used charcoal as a fuel since around 4000 BC, and in the middle ages it was an important industrial fuel, since it burns hot enough to melt bronze, iron, and glass. Charcoal burning was a common profession in the middle ages; the practioners were known as colliers.
The basic process of making charcoal involves heating wood hot enough to drive out the volatile chemicals without actually letting the wood burn. Limiting the supply of oxygen keeps the wood from burning to ash. The most primitive method of making charcoal is to start a strong fire in a pit in the ground and then cover it earth before the wood is consumed. In the middle ages, colliers constructed more sophisticated charcoal kilns by building stacks of wood twelve feet high and up to forty feet across, covering them, and then dumping burning coals through a "chimney" in the middle. The burn in such a pile might last a week or longer.
References
- Charcoal Making: A Brief History from http://www.workingwoodlands.info (No longer available)
- A Brief History of Charcoal from http://www.cornwallwildlifetrust.org.uk (No longer available)
- Fuel For The Fires: Charcoal Making in the Nineteenth Century
- Charcoal Making