[Terrapreta] converting coal-fines into activated charcoal

[Gerald Van Koeverden]

Several previous messages have talked about using coal as a source of  
carbon/char for soil amendment....

Coal is much denser than charcoal, thus doesn't have the properties  
we prize in char or charcoal.

However, if coal could be 'expanded' or 'popped', then it could serve  
the same purpose.  Thus I went looking for applications that try to  
convert coal fines into a form of activated charcoal.  Afterall,  
activated charcoal is a very high end product, and thus its selling  
price could justify a process.

I found one excellent article on such a process.  It has a ton of  
information on charcoal itself too...

http://www.wipo.int/pctdb/en/wo.jsp?IA=WO2006071859&DISPLAY=DESC

Gerrit