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Philip Small

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since Nov 30, 2011
Spokane, WA
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Recent posts by Philip Small

Origin of the term Biochar. Before there was "Biochar" there was "Agrichar". The Terra Preta community dedicated to achieving Terre Preta Nuova by reverse engineering the Amazonian Dark Earth (ADE) phenomenon coined the term "Agrichar" meaning charcoal you would want to use in an agricultural context. I miss those times, the term agrichar was easier to communicate than biochar is.

In 2006 some Australians members of the TP community saw the opportunity to make some money and commandeered the term Agrichar, trade marked it, restricted its use. The meaning of Agrichar became charcoal made by slow pyrolysis that has been enhanced in proprietary ways to perform well ag-wise. The rest of us had to come up with a new name, and biochar is the term we chose. It still upsets me! Fast forward 13 years to 2020, and the term "Agrichar" has disappeared from use.

Biochar, like the term scientist, can cover a wide range of qualities and qualifications. If my life hinges on understanding soil science, and I seek out the knowledge, and achieve soil success, am I not an accomplished soil scientist regardless of whether I paid for a degree or not? Maybe even more so? Yet some (me 15 years ago) would say, if you don't have formal qualifications you can't honestly present yourself as a soil scientist in formal contexts (teaching, public testimony, client reports) at least not without speaking to that detail. Does the term scientist become meaningless if we can't agree on one shared definition?  

It's kind of the same with biochar. I take the position that if I am using charcoal to accomplish improved soil health (or animal health, or compost health), I feel perfectly fine using the term biochar regardless of feedstock, ash content, volatiles content, resulting molecular state (torrefied/amorphous/graphene), process (hydrothermal-carbonization/pyrolysis/gasification/combustion), or post process treatment (seasoning, amending, activating, charging, washing, acidifying, rinsing, crushing). However what I use as biochar often will not meet the definition of biochar established by the International Biochar Initiative, nor will it meet the definition we use among ourselves locally a tribal understanding that without inoculation, biochar is just charcoal. And there are consumer protection issues when even highly caustic black ash, even char stinky with smokey smelling tar, even charcoal made irresponsibly, can be labeled biochar, thus the need to steer folks towards IBI certified biochar products, and towards the inoculated or composted variants favored within our permaculture community as the only biochar worth having. From my perspective, I see no hard and fast rules defining what biochar as a material is and isn't, but I respect anybody who has settled on a definition that works for them, that they are comfortable with.
3 months ago

Jay Angler wrote:... just add some to their feed as a powder and be done with it? Any other suggestions?

Certainly using the charcoal straight is the normal practice. I hear of chickens, of pigs, and in one case an ox, making a beeline to ingest freshly made biochar. And if the animals are having the kinds of feed challenges that one would go to activated carbon to solve, then it is best to use freshly made biochar. Freshly made would be better at keeping the ammonia levels down in the coop, one of the primary assaults on poultry health. But there is more to it than that, and it would be totally fun to compare which biochar prep your chickens prefer. You might find they do best when having access to several types at once.

Rather than grinding the charcoal down to feed grain size bits and mixing it into feed like AAFCO folks would do, gravel and stone size chunks of charcoal work just as well, maybe better. Certainly easier not to have to grind down a bunch of dusty charcoal. Let the chickens do that job. Charcoal is brittle, and can get pecked apart pretty quickly. The long standing practice with smallholder hogs is to give them a charred log end to gnaw on. In the ox incident, after a slash pile burn, the ox walked up after the fire was all out and the biochar had stopped steaming and that ox started munching directly on the chunks of recently water dowsed cinders.
3 months ago
I also would be interested to hear from folks feeding biochar. I know of several poultry producers adopting charcoal after this article:

Article conclusion: "Bamboo charcoal increased the growth performance and feed efficiency, while decreased noxious gas emission and faecal harmful microflora in fattening pigs. Moreover, such bamboo charcoal may protect pigs from infection and reduce stress due to decreased cortisol concentration and increased IgG concentration of serum or blood cell in fattening pigs. Bamboo charcoal is expected to improve swine production as a result of improved gastrointestinal environment of fattening pigs."

Charcoal as a feed additive is controversial because on the one hand, it has centuries of acceptance and demonstrated benefit, and on the other hand, a recent history of being used to pass off low quality moldy feed as high quality feed.

In toxicology, charcoal is regarded as a “universal antidote” to accidental poisonings. In moldy feed, the charcoal dials back the obvious signs in the animal that the feed exceeds established mycotoxin criteria. Because of this fraudulent activity, because of a concern for protecting the feed-purchasing public, in 2012, the USA Association of American Feed Control Officials (AAFCO) gave a ruling effectively banning the addition and manufacture of plant-based charcoal for feeding purposes.

"The [2012 AAFCO] ruling means that feed manufacturers can no longer legally add charcoal powder to feeds or supplements. The reasoning behind the removal of charcoal powder includes but is not limited to: fear of dioxin contamination in charcoal and the indiscriminate use of charcoal in pet food as a mycotoxin binder or for binding other contaminants."


This means that as of 2012 you can no longer get charcoal through an animal feed manufacturer.
As of 2012 you can no longer find charcoal as an ingredient in state approved feed mixes.
Users of charcoal in feed have had to work around this by finding their own sources of charcoal, and mixing their own feed. With the AAPCO prohibition, we won't be hearing much about it from the state, from industry, or from academic channels.

3 months ago

Priscilla Stilwell wrote:... fresh wood ash consists of a large amount of potassium, and that the potassium leaches out when it rains. ...

Note the term "spent lime" as used in this 2004 paper on CA Apple storage:

I believe the term "spent ash", like the term "spent lime" in the linked article, means the causticity has been neutralized, typically by a natural aging process whereby OH and O oxides of calcium and magnesium (and in the case of spent ash, potassium) convert to CO carbonates on exposure to atmospheric humidity and carbon dioxide. Another term that applies is mineral carbon fixation, in that atmospheric carbon is removed in the "spending" process. You can make soap using fresh ash (pH 12 or more) in place of lye, but you can't use spent ash (pH 9 or less) because the original fresh kilned causticity has been partly neutralized.

Spent ash stored outside is likely to lose potassium (K) to leaching prior to losing calcium and magnesium. At pH 9 potassium carbonate is soluble in water, calcium and magnesium carbonate is only slightly soluble. As ash pH decreases further with time, calcium (Ca) and magnesium (Mg) become more readily soluble. Among the other mineral nutrients, you can expect P, Fe, and Mn to resist leaching, and expect B, Cl, and S to be more like K: susceptible to leaching loss during storage.

edit: corrected term
1 year ago

Michael Cox wrote:Hi Folks,
The cone kilns which were first appearing two or three years ago looked promising....

I can see the benefit of a trench pit to handle longer pieces, encourage exploring that approach. The cone kin=ln better fits my situation. Some permie friends of mine, Best Biochar Kiln, in Stevens County, Washington, USA, make shippable cone kiln kits. I have two of the BBK kilns, typically running both simultaneously in a very urban backyard setting. With two and three story apartments on the downwind side, one has to deeply appreciate cone kilns for the ease with which they can maintain smokeless runs. A cone-kiln shaped pit in the dirt would work quite well also. A big wok, there are a number of ways to get the benefit of an open pan shaped firepit. I previously relied on enclosed barrel-in-a-barrel retorts, but the smoky start up, and the smoky hand off when transitioning from primary (outer sleeve) to secondary (inner vessel / retort) gases 20 minutes or so into the run. That meant I had to choose my days and times more carefully, needing to avoiding cold air temperatures and high humidity conditions that the cone kiln handles easily. That said the cone kiln is more sensitive to wind, I avoid 5 mph and above, whereas the barrel retorts were good up to 12 mph days. A windscreen can really help.

A cone kiln can throw sparks that an enclosed retort will retain. With climate disruption, and increasing incidence of red flag fire warning days of high temperatures, high winds, and extremely low humidity, open burn methods for making biochar deserve an added measure of caution.
2 years ago

Steve Jucick wrote:Has anyone tried to reburn a load that did not turn out as well as it should have?

Separating the incompletely burned "brands" to char in the next run is pretty easy if these are too stout to run to compost. The brands are the bits not easily cut with a shovel blade, just poke away at the pile of quenched embers with a shovel, the brands feel resistant, completely different than the char bits. Personally, I like seeing a bit of brands in my finished biochar because it indicates I didn't start into making too much ash, but also because it assures we'll have some low temperature amorphous carbon structured char, non-conductive to electricity. However, only as long as I know that there also hot bits that incandesced (I mean glowed) at a orange/yellow wavelength which indicates we'll have some high temperature turbostratic carbon structure, which has semiconductive surfaces, which I think is important to soil biology. Natural and neolithic fire events surely produce both low and high temperature biochar, I want my biochar type complex like how it forms in nature. Open flame backyard biochar is best for soil biological diversity (health) because it is not uniform throughout.
4 years ago

Gilbert Fritz wrote:Has anyone put biochar in potting mix?

5-10% by volume is a common target rate for soil mixes.
Use only 2-3% if you are making the well drained soil mix preferred by some horticultural growers.
4 years ago
A vac-shredder/bagger with a metal impeller is pretty handy. The bag helps control the dust. Toro makes a little electric vac shredder with the right impeller. Stihl has a back pack gas powered one. Bob Wells, New England Biochar, uses a stationary vac-shredder to unload his Adam retorts. Note: I found out this doesn't work at all well with wet charcoal.
4 years ago

Nick Kitchener wrote:Hmmm, I see they also sand the char back to the (fire hardened) wood.
I wonder if its the wood/charr boundary that provides the protection. Everything's about edges right?

That is a good observation. Between the charred layer and the unaltered wood is a layer of torrefied wood - super dessicated and very slightly altered. This is the fire-hardened stick stuff of our paleolithic ancestors. The torrefied layer is harder, less absorbent, and more resistant to deformation than charcoal. Sounds applicable to posts.

Real charcoal you should be able to crush and break in your hands. When we make biochar, and can't break a charred limb with a shovel edge, we call these "brands" and save them for the next fire. The cores are torrefied.
That said, I have never been able to make a satisfactory fire hardened stick point using softwood.

Casper du Preez wrote:... I cannot seem to get the charcoal "gas" to ... flame. ... should I try wood instead

No direct experience, but have worried on this bit conceptually.
Maybe the charcoal has no syngas left to give? Seems to me charcoal made to fuel a gasifier should come with more BTU's left per unit volume than more-heat-distilled charcoal made for not-fuel uses, like feedstock for activated carbon, or adding to animal feed. Can you get more-assuredly gasifier fuel charcoal??

Per often repeated internet advice:
Don't use wood gas to fuel an internal combustion engine prior to taking the precautions needed to avoid seizing up the engine due to tar.
4 years ago