The use of charcoal isn't discussed in most eco oriented
magazines for some reason. I think it is viewed as too much
work and not ecological. Some energy is lost when going from
wood to charcoal and the process does require a lot of
wood handling.
This begs the question; why do some cultures spend so much
time making charcoal?
The answer i've found indicates that at some sites we might
want to reconsider use of charcoal. Some advantages of charcoal
are:
1. It is concentrated energy that can be stored in a smaller
space than wood.
2. It is easier to transport.
3. It produces less smoke and gas when burned.
4. It can be combined with clay and ashes to create
slow burning fuels.
5. Twigs and tree trimmings make excellent charcoal and
often this fits better than harvesting trees for
firewood.
The big advantages are the clean burning (less pollution in
the house) and the use of twigs which might not have other
uses.
Making charcoal is not very difficult. The goal is to bake all
the moisture out and leave just the carbon. In some areas this
is accomplished by packing the wood into stacks and beginning
a controlled burn. A better way is to construct a kiln of
dirt or some other material and fill with twigs. At the bottom of
this stack leave a channel filled with newspaper. Burn the paper
and once the bottom wood begins to burn, shut all air out except
for a hole at the top. When the smoke stops coming then
either the fire went out or the water has all been burned off.
It soon becomes easy do this with little intervention. The
indicators are the smoke, whether the fire goes out, and the
color of the charcoal. It is done when shiny.
The burning of charcoal is interesting and people burn it
all around the house. Some burn it on the table and cook as
they eat. It can be in a small pit under the table and warm
those who sit at the table. It can be made into balls that
burn all night in bedrooms.
The only application i've had experience with is watching an old
farmer use it for some permeative metal work. I assume he
used charcoal because it got hotter than wood. If this is
true then pottery kilns and glass workers might also be able
to use charcoal.
To make charcoal balls, crush the charcoal and mix with clay/soil
and ashes with a little water. Let dry and use as a long burning
fuel.
