[Terrapreta] Capturing the smoke with charcoal

[Larry Williams]

Rich and I were considering a fan, a squirrel cage style, to draw (so  
that a tower is not required) the hot gasses from the burn to a  
charcoal filter stack. With a little water spray to prevent charcoal  
ignition, would the charcoal absorb a significant portion of the  
smoke? Would the water spray cooling the gasses cause condensation of  
the "bio-oils" (pyroligneous oil,  acetic acid,  poly-aromatic  
hydrocarbons,  etc.  These are more generally called "bio-oils",   
"volatile matter",  "wood tars",  or simply tars---SKB note) to occur  
before absorption by the charcoal? Is there a way of using the inert  
gases to prevent combustion of the charcoal and not use water?

Let rephrase this thought: Can we make a better product of charcoal  
with these out-gasses? Specifically, what is the value of the  
components of the smoke and can we capture the CO2 and methane in a  
charcoal filter?

Sean, as you know, I do not have a scientific background. At the same  
time, I like to understand process, usually that is a linear event.  
As I formulate these questions and reread your last post of April 16,  
2007 11:52:53 PM PDT, I feel that I am answering some of my questions  
so it is difficult to stop at a question because I think I have a  
partial understanding of that question. Thanks for the problem. I  
thoroughly enjoy this.

Thanks to all-------Larry



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On Apr 17, 2007, at 12:12 AM, Greenjack wrote:

> I was inspired by my conversation with Larry. Here is an oven built  
> out of brick (I have been getting it Free on craigslist) It has a  
> slanted shoot in the back to feed prunings, blackberry bushes, and  
> forest debris. It has compressed air, and water to keep the stack  
> from catching fire. 3 30 gallon drums are welded together to form a  
> stack.  The bottom of the stack has a grate welded to it and the  
> stack is filled with lump charcoal.  The smoke from the fire will  
> add the funk back into the charcoal, and we will have cheaply  
> scrubed the air for the EPA. We are now reducing emissions on our  
> process. Add a pyrometer to the stack, and on the fire itself, the  
> operator can control the process.  Pj
> <PICT0478.JPG>