[Terrapreta] Fwd: ammonia and charcoal

[Gerald Van Koeverden]

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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