[Terrapreta] charcoal making

[Richard Haard]

On Apr 1, 2007, at 5:49 PM, Sean K. Barry wrote:

> Hi Richard,
>
> You do live in an area of some beauty.  How long after you started  
> the kindling under the split logs was it when you bury the burning  
> pile?

No kindling, just split cordwood that has been drying for 2 years.  
Larry was late coming out and I started the fire with those paraffin  
impregnated fireplace logs. By the time he arrived 15 minutes later  
it was blazing in 2 places and we worked for about an hour finishing  
the stack with another 1/2 cord of half dry alder, etc and holding  
the fire back with a open garden hose. I think stacking on the  
pallets helped feed the fire with lots of air.

Larry thinks it almost got away from us as the tractor was late  
arriving and the neighbor who came by with some wet hay for us was  
recruited to help with his mini loader bucket.

Larry by the way should be posting here soon as he has been having  
difficulty with signing in. He should have more to say on this.


> Did you leave any small air intake vents/ output stacks at the  
> bottom or stacks out the top?

The first day we had  2 vents in the lower front about 6 inches  
across and the  single vent on the upper end. The deck of the fire  
bed did slope uphill. On the upper end we had buried a standing  
pallet and we allowed a single vent to stay open. There was much  
discussion during the day as i was worried the fire did not have  
enough air and is the reason we opened the lower end at end of day.  
It was really hot and when we covered up for the night we only left a  
vent at the top

This morning I checked and the cardboard and wet hay was still intact  
on the middle and the temp 6 inches into this layer with my 6" probe  
was 160-166 F. Roughly the same as when we left. The upper vent was  
cycling this morning between steam and white smoke. We had planned  
originally to open the pile today but after much neighborhood  
discussions we decided to leave till next weekend. If it seems to be  
cooling we will open the lower vent again and Larry will blow in some  
air with his lawn blower.

Our local friends told us stories about a burn pile with buried hot  
coals that lasted all winter and another told us about forest fire  
burns at  that stayed hot all winter at loading dock piles under many  
feet of snow.

I am very interested that this technique did not make excessive  
smoke, which is a big plus in my neighborhood. We should look at a  
version of this burn where we scrub the outlet gasses to make wood  
vinegar. Any ideas?

I am impressed with the Indonesian flat kiln Tom put the pdf into  
files section. It would fit well with my willow coppice work

> Who is the John you refer to?

John is John Flottvik, our neighbor just across the border in Canada  
who manufactures a pyrolyser and has been keeping me well supplied  
with charcoal powder during the 2-3  years of my farm experiments. I  
think his current company name is JF Waste Bioenergy. He reads this  
list.


> Are you the two pictured?

Yup That's us. I had emailed Tom during our burn and told him he  
could call in to kibbitz, which he did and we had a great  
conversation. Later he commented to us we should have been in costume  
so i suppose next time we should wear our SCA (Society for Creative  
Anachonism) outfits.

> Did you measure or estimate the weight of the wood you put into the  
> pit?

Three pretty full loads in my (old) Nissan pickup about 1 and 1/2 cords.

> Will you measure the weight of the resulting charcoal?  Will you be  
> doing a proximate analysis of the charcoal?

Probably not, since we quench in water and my experiments will be set  
up by volume. I am looking for about 80 gallons of charcoal pieces  
for this treatment set. We also hope to save an equal amount until  
next year by composting in forest litter in the active root zone of a  
mixed conifer/hardwood forest. Larry will also be taking the small  
bits and dust for his garden.

Proximate analysis will be done and  also all treatments and  
additives will be subjected to:  pH, Buffer pH, Extractable  
Nutrients, Extractable Heavy Metals (e.g. Lead), Cation Exchange  
Capacity, and Percent Base Saturation.

And of course OM. Pretty much standard farmer stuff.

As we had covered the burn pit with wet hay and farm soil the char we  
harvested yesterday was contaminated with these materials but as this  
is going to be mixed in with the same soil i am only going to  
separate the big pieces of soil and hay and not worry about washing  
the charcoal. Larry is thinking about burning the hay pieces with his  
propane weed burner but I think I want to preserve those volatiles.  
What do you think?

>
> Good luck with your "Terra Preta" making adventure.  I hope you  
> have some interesting results with the pot tests also.
>
re "Terra Preta" Larry and I have had much discussion on this and we  
have decided to separate the use of this term from charcoal in  
agricultural soils.

Me too, this is a big effort and I want to get it set up right. An  
advisor with more experience than I with pot experiments (and  
charcoal!) commented to cut back on treatment sets and increase the  
number of replications. I am in the last step of deciding this now  
and will be focusing primarily on depleted farm soil that has just  
finished a 2 year rotation and focus closely on our current  
fertilizer and OM amendment protocols. Even irrigation is a worry and  
I have decided to place the pots in our field and give them the same  
irrigation sets as our seedbeds.

Best

Rich Haard, Bellingham, Washington
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/terrapreta_bioenergylists.org/attachments/20070401/24ebaa05/attachment-0001.html