Fuel from the Fields: Charcoal from agricultural waste
Practical Action
• Place a large stick (figure 7) in the centre of the
drum and pack the bagasse, stalks or other material
around it until the drum is full.
• If you are using corn cobs, or other material that is
more difficult to light, create 4-5 layers of corn cobs,
separated by husks or dried grasses. This allows the
whole drum to get hot, and produce high quality
charcoal.
• Carefully remove the stick, leaving a hole that goes to
the bottom of the drum.
• Take a small amount of material and poke it into
each of the holes in the bottom of the drum, leaving
about 20 cm sticking out. (figure 8) This creates a
wick, allowing you to easily ignite the material at the
bottom of the drum.
Figure 8: Make ‘wicks’ in the
bottom of the oil drum. Photo
credit: Fuel from the Fields.
Lighting the fire
• Before lighting the fire, place the drum on top of three stones or bricks, so that air can flow in
through the holes in the bottom. (figure 9). Place the drum on the stones carefully, so that it
will be easy to remove the stones while the raw material is burning, to seal the drum.
• Light the wicks at the bottom before you light the loading hole on the top. One good way to
light the top is to light a long piece of the biomass on one end and then drop it in the central
hole, made by the stick. Sometimes the fire catches fast enough that you do not need to light
the top.
Once the biomass is fully on fire, it will make a large, billowing plume of white smoke (figure 10).
Figure 9: Raise the drum on three flat
stones, and light the wicks at the
bottom. Photo credit: Fuel from the
Figure 10: The first, light
plume of smoke. Photo
credit: Fuel from the Fields.
Take care to stand upwind from all the smoke, to avoid inhaling it.
After about 10 minutes, the smoke starts to get a bit darker, thicker and yellower. As the drum gets
hotter, volatile carbon gases begin to be formed. These can be ignited to make the fire burn more
cleanly, giving off carbon dioxide (figure 11).
• Light a match and throw it into the top of the drum. If it is too soon, the smoke will not ignite.
If the timing is right (volatile carbon gases are evaporating) the smoke will catch on fire and
the fire will burn much more cleanly.
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