Jumping in to Terra Preta

[Hap]

Just posting the obligatory "hello" so I can share my experiences in the Terra Preta forum. I noticed in a "charcoal" thread that a few folks were a little misguided in what they wanted to achieve. So here I am. All registered and ready to share. Since the main thread has been closed and the follow-up link gives me the "secret of life" error page I guess I need to go track it down.

 

However, Howdy to all and thanks for the interesting site. I look forward to sharing.

 

H

[Essay]

Welcome Hap,

We can always use new blood in the TP (pun intended)....

:phones:

 

So feel free to ask about the misguided understandings, or whatever....

...and what link is dead? Lemme know, and maybe something can be fixed.

 

Have fun reading, ranting, or raving... or even revising....

 

Cheers!

~SA

[Michaelangelica]

Hi welcome

this is a big site If you get lost or confused send me a PM

Welcome B)

[Hap]

Thanks for the 2 replies back. I did find the Terra Preta thread I needed. the link at the end of "the mother of threads that started it all" was a dead link but there is a terra preta group. I had a fairly large post in progress when my browser crashed B)

 

After that I pretty much just packed it in for the night. I'm back now so I'll find my way back and get that post going.

 

We own land in Texas and started out with very small batches using baking pans filled with various materials and used a BBQ grill (with cheap high-temperature insulation) for testing and reaching the needed 450C (842F).

 

After that, we changed gears a bit and ramped things up using a combination of homemade solar furnaces (fresnel lenses), wood gases created from the process, and on occasion methane from digesters and ambient solar heating to dry material with over 25% moisture.

 

It's not a fast process, but the time you spend at 450C is critical to the process. Some folks seem to think that terra preta is "charcoal" ... it may look like charcoal but it is actually a lot more complex. The temperature and time will dictate how much internal surface area you have in your char, and how much of the nutrients you retain from the original biomass. Longer charing times and higher temps generally give you more surface area but less nutrients, shorter times means more nutrients but a lot less surface area.

 

Well, I'm off to do my post in the Terra Preta group. Of, the magic numbers are 450C (842F) for 51 minutes with a moisture content of less than 25% in the material. You also need to char it in an airless environment (as much as possible). Anything that turns to ash is basically worthless. Higher moisture content makes it harder to maintain consistent results. The other key aspect of making it is a diversity of materials and the inherent nutrients and minerals in each individual material.

 

Good luck to all! I look forward to our future discussions!

 

H