[Terrapreta] Fwd: ammonia and charcoal

[Edward Someus]

Gerrit/Brian 
 
 RE Charcoal is a strong hydrophobic  
YES, when the char is not properly produced for biotech applications and
containing tar residuals you get this phenomens. The hydrophobic effect is
the property that non-polar molecules tend to form intermolecular aggregates
in an aqueous medium and analogous intramolecular interactions. This is why
the fresh char first adsorbs water than release it. Repeated thermal
treatments may change some this character, but in the industrial application
reality, there is no economy to thermally treat char again. 
 
 

Sincerely yours: Edward Someus (environmental engineer)
Terra Humana Clean Tech Ltd. (ISO 9001/ISO 14001)
3R Environmental Technologies Ltd. 
ADDRESS: H-1222 Budapest, Szechenyi 59, Hungary
TEL handy:  +(36-20) 201 7557
TEL / FAX:   +(36-1) 424 0224
TEL SKYPE phone via computer:  Edward Someus
3R TERRACARBON:   http://www.terrenum.net 
3R CLEANCOAL ENERGY: http://www.nvirocleantech.com 
 
-------Original Message-------
 
From: Gerald Van Koeverden
Date: 2008.02.09. 15:51:45
To: Terra Preta
Subject: [Terrapreta] Fwd: ammonia and charcoal
 
Fresh biochar exhibits strong hydrophobic properties.  But biochar that has
been sitting around in the open exposed to rain is totally opposite.  When I
dry this biochar out, and then re-expose to moisture, it soaks up water like
blotting paper.   


This change in physical property must be a reflection of chemical changes -
at least on the surface of the pores.  Has anybody seen a study of how
charcoal/biochar changes chemically over time, comparing the changes in
wetted versus dry-stored.


This could be important, eg in using it as an ammonia absorber in making
compost.  Charcoal that has been soaked first in water, might have a very
different ability to act as a nutrient "sponge."


Gerrit




Begin forwarded message:


From: Gerald Van Koeverden <vnkvrdn at yahoo.ca>
Date: February 7, 2008 10:41:00 PM EST (CA)
To: terrapreta Preta <terrapreta at bioenergylists.org>
Subject: Fwd: ammonia and charcoal


The nature and strength of the electrical charges inside the charcoal
particle, might also be important for anchoring microorganisms in it as a
microhabitat.  For example, bacteria tend to have a negative electrical
charge.



Begin forwarded message:


From: Gerald Van Koeverden <vnkvrdn at yahoo.ca>
Date: February 7, 2008 5:04:55 PM EST (CA)
To: terrapreta Preta <terrapreta at bioenergylists.org>
Subject: Fwd: ammonia and charcoal


to follow up on ammonia absorption in charcoal... 


it's interesting to note that there is no direct relationship between
charcoal porosity and ammonia absorption.  In fact, the absorption of low
temperature-made (400 degrees) bamboo charcoal treated with a dilute
sulfuric acid is twice that of activated charocal which has a pore surface
area eight hundred times greater. 


http://jhs.pharm.or.jp/data/52(5)/52_585.pdf



Gerrit


Begin forwarded message:


From: Gerald Van Koeverden <vnkvrdn at yahoo.ca>
Date: February 7, 2008 3:51:02 PM EST (CA)
To: terrapreta Preta <terrapreta at bioenergylists.org>
Subject: ammonia and charcoal


Could chemical interactions between ammonia and charcoal be the initial key
for how charcoal is gradually transformed into that found in terra preta?


"Australian researchers have discovered a cheap and simple way to make
sheets of carbon just one atom thick.
Their finding has implications for a range of developments from solar cells
to bionic ears.
The sheets, known as graphene, normally stack together to make the kind of
graphite used in pencils.
But when separated, graphene sheets have extraordinary electronic, thermal
and mechanical characteristics, says Gordon Wallace from the University of
Wollongong in New South Whales, Australia.
"People have known that if you can separate sheets of graphene from graphite
you can get some pretty interesting properties," he explained.
Most researchers thought creating these sheets in a cost-effective way was
an insurmountable challenge, due to their strong tendency to clump together.
But in the journal Nature Nanotechnology this week, Wallace's team shows
stopping the sheets from aggregating is actually a fairly simple matter.
The Australian team did not use chemical stabilizers to keep the sheet apart
 Instead, they used water with some ammonia added to increase its pH value,
making it more alkaline.
"It's actually a really simple discovery but with fairly significant
implications," Wallace said.
"It's a matter of understanding that simple chemistries can be applied to
graphite sheets."
Increasing the pH of the water raises the electrostatic charge on the
graphene sheets, he explained, making sure they repel one another instead of
clumping together.
This low cost approach raises the possibility that scientists could produce
large amounts of stable graphene that could be used in a range of settings.
"The very unusual electronic properties of graphene sheets means they could
be used in solar cells or new battery technology," he said. "Because of the
biological affinity of carbon, they might also be useful as electrodes for a
range of medical bionic devices such as cochlear implants."




http://dsc.discovery.com/news/2008/01/29/nanotech-carbon.html


Ammonia and water - being the main ingredients in urine - could easily have
been added to charcoal by native Amazonians.


It is apparent that ammonia changes the chemical nature of carbon molecules.
 To effect charcoal, it would need transform only the innner pore surface
area of the charcoal particle to dramatically change its CEC, without
affecting its overall physical structure.


This afternoon, I added a saturated solution of ammonium nitrate to biochar
to compare with a control of pure water mix.  Once I let it sit for several
days, I'll dry out the samples and then see if I can see any difference in
how they re-mix with water.  


Unfortunately, I don't have any lab equipment to then test to see if the CEC
has changed.  I'm trying to think of simple tests I could do to find out
what, if any, properties have changed, for example:


a)  putting a large drop of water adjacent to the pile of char to see how
quickly the char sucks it up as a test to see whether its hydrophobic
properties have changed.


b)  using the two samples as a filter for various aqueous solutions to see
if there is any difference in what they filter out of them...






 
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