[Terrapreta] Strong warning against "simple" charcoal kilns

[Duane Pendergast]

Lorenzo

 

It would be quite a trick to devise "pyrolizer units that maximally exploit
the energy content in the biomass and that minimize greenhouse gases".
Maximizing energy use would require converting the carbon content to CO2. I
guess you are suggesting finding some optimum balance between energy use and
greenhouse gas production if such can be defined.

 

I agree the vision of millions - or billions - of primitive charcoal kiln
does not seem to reconcile easily with environmental regulations for all
kinds of atmospheric pollutants. I suspect even modest use of them her in
Canada or the US would soon attract undesired attention from regulators.
Relegating them to undeveloped countries they would be out of sight and out
of mind doesn't work either. However, some use of them to economically
produce char for experimentation seems reasonable. 

 

Is it possible to devise a process which derives the energy needed for the
process just from the hydrogen content of the biomass while converting all
of the carbon content to char?  Would it be reasonable to use some external
energy source, such as electricity, for the pyrolysis process so evolved
hydrogen could be used for other purposes such as transportation fuel? Could
char production be maximized by some such process? 

 

 

Duane

 

 

-----Original Message-----
From: terrapreta-bounces at bioenergylists.org
[mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Biopact
Sent: April 27, 2008 8:29 AM
To: terrapreta at bioenergylists.org
Subject: [Terrapreta] Strong warning against "simple" charcoal kilns

 

It has been repeated here a few times. We should be careful not to ruin the
potential of Terra Preta by coupling it to inefficient, GHG emitting
charcoal devices.

 

Many of these simple devices are 10 to 20% efficient at best. Biochar's only
way to make a difference is by using highly efficient pyrolyser units that
maximally exploit the energy content in the biomass and that minimize GHG
emissions. Syngas, heat, pyrolysis oil - all these he byproducts must be
explicitly used to offset fossil fuels. 

 

So I urge all of us to limit references to "simple" charcoal kilns, and then
only in the context of biochar trials that look at the effects of char in
soils. For the rest, I think we should continuously stress that one of the
most urgent needs is the development of highly efficient pyrolysis units.

 

Else, we could be ruining the entire Terra Preta venture. Remember, there
are many people reading these texts, and they may spread amongst
journalists. If they get the impression that we are a bunch of people who
just pyrolyse our way through this concept, then the initial potency of the
very concept may get lost. 

 

Cheers, 

Lorenzo

-------------- next part --------------
An HTML attachment was scrubbed...
URL: /attachments/20080427/a46487ee/attachment-0001.html