Make Your Own BioChar and Terra Preta

Intro: Make Your Own BioChar and Terra Preta

A simple way to make BioChar in a 55 gallon drum. Hoping to promote simple, scalable, environmentally sound methods for making biochar for improving the soil on small farms and in backyard gardens. And improving the air as well.

When you bury the carbon you are sequestering it out of the atmosphere for hundreds of years. A pound of carbon buried this way takes quite a bit of CO2 gas out of what's overhead.

http://en.wikipedia.org/wiki/Biochar
http://en.wikipedia.org/wiki/terrapreta

This is a collaborative on Instructables.com; you are invited to upload your tweaks, photos, facts, refinements.

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STEP 1: Overview

Cartoon of the process. I would like to sketch some more designs and have people test them.

STEP 2: Prep & Materials

Materials:
55 Gallon Drum, with Lid
Drum sealing ring
Dry Biomass - usually wood & wood chips, or dung
water
compost

Tools
Hoe, rake, shovel
Dust mask, ear protection, eye protection
Heavy gloves, boots
Hose & nozzle
Metal cutting circ saw or hammer & chisel

STEP 3: Make the Charcoal

Seal up the lid and roll the drum onto the fire. You want the vent holes pointing down into the fire so that methane gases get flared off before they escape into the atmosphere, causing atmos damage.
The drum has to sit on the fire for several hours. First steam comes out for 2 to 4 hours, as the water boils off. Then, volatile gases (VOC's) such as methane and hydrogen start blazing out of the slots like blowtorches, for 1 to 2 hours. When the gases have all flared off, there will be little or no smoke. The carbon will start to burn, sucking oxygen into the barrel. That's when you want to stop the process by rolling the drum off the fire and covering the slots with sand to starve the oxygen. Water helps too, since you're happy with wet charcoal.

STEP 4: Remove From Fire and Cool

Watch out for hot ground, hot sand!

STEP 5: Making Biochar Into Terra Preta

Crush the charcoal with your grape smashers (boots). Add fungal wood chips, household compost, (especially milk, fish, and bones) leafy compost, chicken gickem, urine, grey water, worm tea, fish tank water, you name it! Try to get the charcoal juiced up with calcium, nitrogen, bacteria and fungus before you put it into your garden. Enjoy it for hundreds of years! The ancients added pottery shards, which may absorb toxins, but I like to use my hands in the soil, so I don't add that. Do add crushed clamshells and eggshells.

You just sequestered some carbon!

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Find out everything - International Biochar Initiative, http://www.biochar-international.org/
Hat Tip to Gunther Folke & his retort method: http://www.holon.se/folke
Join the Biochar group here at https://www.instructables.com/group/BioChar/
Check out http://www.DIYbioChar.org to participate and vote in design competitions (going live March 2009)
Take political action!

Comments

[JohnBonitz]

 This is very helpful!  Thanks for making this Instructable.  

However, please note that THIS method of charcoal production is NOT climate-friendly.  Any combustion process that releases un-burned gases will actually exacerbate the greenhouse-effect.  The simple pyrolysis/gasification effect created in this steel drum will release gases called "volatile organic compounds" or VOCs, including methane.  This looks like smoke or fumes, and may be gray or yellowish in color.  

Methane is a gas that is 20 to 25 times more potent than CO2 in trapping heat in the atmosphere.  In other words, the effect of the gases you create while making biochar could exceed the carbon-capture benefit of biochar in soils. 

To fix this, you have two options: 
1) make certain that any gases you create (i.e., "smoke" or "fumes") are burned or flared, thus reducing the VOCs to CO and CO2 (less potent GHGs than methane).
2) even better, engineer a system to make use of these gases for thermal energy.  Waste-not-want-not!

Cheers!

[e2737094]

Better hope there is global warming and not global cooling.

[KatyBearCookieCompany]

Sugar plum, honey bunch, we are entering a grand solar minimum and a mini-ice age. We have 90% crop failures in the USA and pretty much worldwide. The USDA, bless their little souls, are doing their best to sweep the problem under the rug because they can't find their heinies with both hands.
Red China has come out and said their scientists have come out and said northern China has had crop failures due to cold 7-8 years in a row. They said the ice age may last 250 years.
I sincerely hope they are wrong. At any rate, every human on earth needs to start growing their own food and teaching others how to do so.
As a biologist/biochemist I agree about toxic compound creation with you, but we do not have global warming. We have a natural earth cycle that is warm period followed by instability followed by ice age.
Geologic records show it was hotter when the dinosaurs were around and humans didn't exist.

[89marys]

all you said is right, the mini ice age will start in 2100 . and human just accelerate the natural earth cycle.

[jen100098]

More potent still is water vapor, which comprises the majority of greenhouse gas.

[kludge000]

seachar.org

[kludge000]

This is one of the least efficient method of making charcoal and does not even guarantee that you will have any bio-char when you finish. FYI Bio-char is characterized by the presents of cations on the carbon molecules and is created between the temp. of 700C and 800C in the presence of some water. I agree with you about the climate friendliness of this method. It could be if his production process offered more control and if the biomass was destined to rot or be burned anyway. Look for this on facebook it is a good working group for bio-char production in a responsible way.

[Arthur Young]

I always have pieces of charred wood when I clean out my wood heaters. Can I grind these into powder and use them as biochar? Do they have the same fertilize value?.

[jen100098]

If I were in your position I would use some kind of screen from a trash pile of fencing material to catch the big chunks and sift out the rest. Then I'd thoroughly mix the biochar with whatever soil I'm trying to enhance in a gardening area after digging it out. Then I could bury the wooden chunks that aren't really burnt up where I plan to have the garden and push the new biochar enhanced soil over it. Over decades, you may see a slumping of the ground due to decaying of the wood. In that case you can pile on more dirt from the surrounding area. After all, the wood would be displacing the local dirt, so its 6 of 1 and 1/2 dozen of the other. The other option would be to take it out and use it as fire starter for the next time, since partially burned wood makes the best kindling.

[jen100098]

Interesting idea, burning fibrous material and releasing carbon into the atmosphere to use the heat to charcoalize other fibrous material, releasing CO and CO2 through venting, to then bury the charcoal, to trap carbon in the ground.

[KatyBearCookieCompany]

Dear Sir,
I am a research dietitian/biologist/biochemist and Texas master gardener. I have been doing organic gardening since 1972, organic companion planting since 1973, and organic farming/ranching with my hubby since 1992.
I am using an Android type phone. Your sketches, text and photos cannot be enlarged on this website. In other words, I can't see a darn thing.
You need a website that is cell phone friendly.

[terrapreta123]

Very helpful diagrams and photographs, thank you so much

[Pojasmail]

Thanks for sharing this. Is it possible to make the holes on the bottom of the barrel and burn it upright with the holes at the bottom? thanks.

[sasham]

Correct wikipedia link is: http://en.wikipedia.org/wiki/Terra_preta

[kludge000]

seachar.org

[kludge000]

Thank you for your link. I found it to be both accurate and encouraging. FYI the article on wiki about bio-char is not correct on a couple of important points namely it's def. of bio-char. Here a link to a good working group on Facebook.

I first meet the founders at an international symposium on bio-char in Richland, Washington. Later I attended their workshop in Seattle, Washington, where I learned to make T-LUD stoves that had been optimized for bio-char production.

[al4white]

If you are burning a fire to make the biochar its releasing CO2. Does the amount of biochar you make offset this release? Would be good to figure out a simple way of capturing the syngas and re-using it to make biochar.

[blazingpencilsdotcom]

Thanks fyc. The carbon that is collected as charcoal is highly recalcitrant - it doesn't evaporate to the atmosphere for many years, as it otherwise would if the wood was decomposing. So there is a net capture of CO2. The syngases are directed downward into the external fire and burned to help generate heat, so they are being used to make biochar. The efficiency of the system could be improved by building an external housing that would conserve heat from the external fire and direct it around the barrel, perhaps towards a cooking platform or water jacket, and up a high chimney, perhaps with an afterburner. I hope you can improve the design and participate in biochar online forums.

[blazingpencilsdotcom]

Update - I added llama poop and compost to the charcoal, let it stew for a couple of weeks an worked it into my soil last fall. This year my gardens seem really happy, my friends say my stuff is bigger and greener than theirs. That's as scientific as I got right now. It's a lot of work, & it's not super friendly to the atmosphere in this lo-tech method, so I'm not recommending it for everybody.

[JohnBonitz]

This is very helpful!  Thanks for making this Instructable. 

However, please note that THIS method of charcoal production is NOT climate-friendly.  Any combustion process that releases un-burned gases will actually exacerbate the greenhouse-effect.  The simple pyrolysis/gasification effect created in this steel drum will release gases called "volatile organic compounds" or VOCs, including methane.  This looks like smoke or fumes, and may be gray or yellowish in color. 

Methane is a gas that is 20 to 25 times more potent than CO2 in trapping heat in the atmosphere.  In other words, the effect of the gases you create while making biochar could exceed the carbon-capture benefit of biochar in soils.

To fix this, you have two options:
1) make certain that any gases you create (i.e., "smoke" or "fumes") are burned or flared, thus reducing the VOCs to CO and CO2 (less potent GHGs than methane).
2) even better, engineer a system to make use of these gases for thermal energy.  Waste-not-want-not!

Cheers!