[Terrapreta] Terra Preta & Pigs

[danny day]

Christoph may answer this himself as I am forwarding the post.  I have
been making char and activated charcoal commercially since 1994 and
from many different biomass sources; such as walnut, peanut shells,
pine chips, pine bark, pine needles,  coconut, cherry pits, peach pits
(watch out for cyanide formation) pelletized cotton gin trash (pretty
good water filter carbon), pistachio shells (do you know how many you
have to eat to get a good sample, cotton stalks (good carbon) corn
cobs, hay, papermill trash, pecan shells (we ordered a sample...a
loaded tractor trailer showed up), palm husks, every kind of wood
grown in the southeast, and on and on.  The plant ran 24-7 and so did
the lab producing and testing samples since it was also quality
control.  There is a mountain of data and lots of little interesting
applications, however...

Every biomass will give you different isotherm (adsorption curve).
The same biomass but grown in a different soil will produce a
different char.  Minerals act as a catalyst and drive reaction rates
so nicely planned experiments of the same biomass grown in different
soils can give puzzling results. I had to shell two truck loads of
peanuts grown in diffferent soils to identify the range of adsorption
capacity possible. However, you can get dependable results with
appropriate testing,  charecterization and feedstock control.  Lose
feedstock control and you can have really different types of carbon.
Feedback loops on thermal processes (depending on precision sought and
size)  can have you whipsawed out of target conditions for half a day
with a bigger sizes (my unit was a 1ton/hr).    Lots of replications,
stored duplicate,or triplicate samples and testing will give you
assurance that the material you tested will give the same answer if
one of the backup samples were re-tested.  However, that does not
guarantee the quality of a large shipment. Laboratory testing using a
known and certified standard for callibration is needed to compare
results between laboratories.  That is why certified standards of
charcoal designed for a specific measurable charecteristics will cost
hundred dollars or more for a one kg container using one or more
specific tests.  Charcoal has components both physical and chemical
that impact adsorption, like surface charge, formation of graphitic
platelets and their orientation, pores size, pore shape, pore size
distribution, particle size, particle hardness, the gradient
distribution and molecular weight of volatile compounds formed inside
a particle and the list goes on.......   It has a memeory of how it
was formed, responding differently if heated fast or slow.  To get a
carbon with different minerals, different percentages of cellulose,
hemicellulose and lignin to come out predictably like a different
biomass requires its own formula, which we trust with collective help
we can make available freely as they are derived.

One of the most well known activated carbon companies that dealt in
biomass carbons had a large inventory of different product types of
activated carbon.  They made many of them under identical conditions
but with different surface area, pore size distribution, and iodine
numbers. Whallah! They were given a different product name.
Brilliant!  While the adsorption performance of a specific compound
may allow a charcoal to be named for its performance and not require
each test be conducted, we are working in a complex ecosystem with
rapidly changing biological components that may only exist for a short
time.  Until we get a collective handle on these variables, the secret
will still be in the art of terra preta, learned through trial and
error.  If we had a few decades to ferret out all the answers we could
afford to let everyone learn what works for the specific soil, but
obviously we don't.

We are finishing a DOE hydrogen project April 25th and would like to
have funding in place to deliver a standardized char for testing.
http://www.youtube.com/watch?v=SnmanHS7dXE

Our unit was designed for accuracy in producing both a gas stream for
hydrogen production and a tightly controlled (temperature and
pressure) continous pyrolysis environment. We look forward to making
char available soon.

I trust you all are well and if you have questions, please feel free
to send me an email as well as post on the board.  If I don't respond
to the email, please send it again.  I am trying to get as many
answered as I can, but sometimes they can fall between the cracks.

Danny Day
EPRIDA


On 2/24/07, Richard Haard <richrd at nas.com> wrote:
> Excellent post Sean. I fully agree with your proposal and do hope there can
> be a collective effort to do good experimental studies.
>
> As a side note I did ask Christoph Steiner at the 2004 Georgia conference
> where he got his charcoal. He told me he gathered it locally. The impression
> I had is he picked it up at various sites where surface burning left
> charcoal.
>
>
> On Feb 24, 2007, at 4:10 PM, Sean K. Barry wrote:
> Christov Steiner is the only person who's research I have seen who is one
> who has actually attempted to "make" Terra Preta.  He did it in Brazil.  He
> added charcoal and NPK fertilizer to soil and grew plants in it next to
> control groups.  A.k.a. he used real science.  How he made the charcoal, at
> what temperature, from what materials he made it, in what concentrations he
> mixed it into the soil, is not entirely known.
>
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>