[Terrapreta] charcoal making

[Larry Williams]

Sean-------Thanks for your recent comments for they peak my interest  
in producing a product that closely follows the Terra Preta results.

I had not considered weighting the wood before the burning. I see the  
benefit of doing so when compared to the finish product, charcoal.  
Given the varying degrees of moisture in the wood due to the drying  
process and storage conditions, It seems that having a figure for the  
water weight is important in determining the efficiency of our  
technique. Does this mean that a moisture meter is important? Or just  
weighting the wood prior to the burn?

In this current burn, still in progress and with close to 1/3 of the  
burn uncovered to examine the burning process and the charcoal, some  
of the best looking charcoal is the green alder poles uses to prevent  
or slow the roof of the firing chamber (clamp?) from collapsing thus  
creating an O2 access to the burn. These poles were of different  
sizes ranging from 3-6" at the butt end and close to 6' long. They  
were not meant to be a portion of the product. Alas, I can't refuse  
this unintended addition.

Although, it does, in my mind, raise some questions about reusing  
excess heat above the clamp to increase the percentage of charcoal  
and about the quality of the green wood charcoal verses the dried  
wood charcoal. Are the off-gasses that can be potentially captured  
different?

When to the questions end? Maybe when food abundance is achieved and  
the Pacific NW cools down a little.

Again, at this time, my interests is in how to make the charcoal  
attractive to the soil critters. I am just trying to establish a  
chain of events that was discovered about 8,000 years ago-------Larry





On Apr 1, 2007, at 8:53 PM, Richard Haard wrote:

>
> 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

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