[Stoves] Stoves in China

[Crispin Pemberton-Pigott]

Dear Ron

I am relieved that you have a use for the charcoal, but in terms of working
out the energy used, I have to ask the question anyway.  If there is no
local application involving the charcoal, I am afraid that it will be tossed
underfoot and counted as 'wasted' which means 'used' as far as I can see.

We talked a few months ago about whether or not a stove can burn the
charcoal that it produces.  A 3 stove fire definitely can.  Therefore the
charcoal is not wasted in a 3 stone fire as it is with some stoves.  It
occurred to me that adding a grate to some stoves would support the burning
of charcoal that was otherwise wasted so it might be an addition that would
generate extra CO2 offsets.

There was one proposal that the stove not be allowed to deduct the charcoal
from the heat applied to the pot if it was not able to burn it later. I
wonder where that puts the terra preta question?  Does that count as 'not
consumed' in the fire?

As is obvious, if a person goes back into the forest to cut more wood, then
there is a problem.  If I have a gasifier that requires 2 kg of wood each
day, making 1 kg of charcoal is not helping the forest re-grow.

So the offering of a gasifier that will use a non-woody biomass is an
alternative arguing against the counting of residual char as a 'loss'
because it would probably not have been used for cooking anyway in many
cases.

Roger Samson points out that very large amounts of rice husk are freely
available so counting the char as 'lost' (because there is no application
for it) and therefore should be counted as used during cooking may be
unfair.

I see two paths emerging: only counting energy offered to the pot during
cooking, and the total energy equation including what happens in the forest.

It seems that using rice husk is clearly a wood substitute. The stove leaves
a low-carbon char.  At least we can now get the actual heat offered to the
pot and work out whether a stove has been improved or not, and see how it
directly compares with other stoves using wood or non-woody fuels.

Regards
Crispin

-----Original Message-----
From: Ron Larson [mailto:rongretlarson at comcast.net] 

Crispin:

Tsk tsk -  I am surprised you wondered today about chacoal having value (a 
little of your message kept below).

    Come visit the "terrapreta" sister site and you will find dozens of 
people looking for some charcoal.

[snip]