Fuel from the Fields: Charcoal from agricultural waste
Practical Action
Figure 6: Parts of the briquette
press. Photo credit: Fuel from the
Fields.
• The cup is made from a large, hollow pipe, with sheet metal welded to the bottom. The
bottom should have a hole drilled in the centre, wider in diameter than the ejector pin.
• Cut two sheet metal discs, slightly smaller in diameter than the inside of the cup. These
form the ejector and plunger plates.
• To make the ejector, weld the ejector plate to a short length of pipe. The ejector should
be as tall as the cup. When using the briquette press, the bottom of the pin is pushed on
the surface of the hammering station, to eject the briquette. If the ejector is as tall as
the cup, the briquette is ejected completely, and the ejector pin stays in the hole at the
bottom of the cup.
• To make the plunger, weld the plunger plate to a length of pipe.
• The hammering station is made by drilling a hole into a table or block of wood. The hole
must be larger in diameter and length than the ejector pin, but smaller than the diameter
of the cup. This allows the base of the cup to rest flat on the surface of the table, with
the ejector pin dropping through the hole, while the press is in use.
Making charcoal
The process of charcoal production is as much an art as a
science. It requires experience to produce high quality
charcoal, and to get high yields of charcoal from an oil drum.
The method must also be adapted slightly for different
materials. Whilst this guide provides approximate details, the
time required at each stage is variable; there is no substitute
for experience.
When conducting a charcoal burn, it is important that the
weather is dry. It is possible to make charcoal when it is
raining, but it is much harder to light a fire. The oil drum also
cools down more quickly, so the yield is lower.
Filling the drum
When filling the drum, it is necessary to allow air to flow
through the drum so that the fire can burn hotly and evenly
and produce high quality charcoal.
Figure 7: Fill the drum with
a central chimney. Photo
credit: Fuel from the Fields.
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