I have heard from more than one source that while biochar is excellent for the tropics, it isn't so good around here.
I can think of one obvious downside: the amount of work it takes to make biochar. It would be way easier to put wood right into the soil.
And pollution: it seems like a lot of pollution to make biochar.
In the tropics, there is very little soil. The organic matter is stored in all of the currently growing trees and shrubs. But in the cooler climates, topsoil builds. In some areas, organic matter can built to be dozens of feet thick: peat bogs come to mind.
Maybe somebody that is a fan of biochar can add some clarity here?
Or maybe some folks have some info that might support these thoughts?
The pollution is a real concern. And it is more work than mulching in place. But if it does half of what the proponents claim, and it is still in the soil and active after a decade or two, it might be worth it.
I really like its potential for seemingly changing soil texture, not just soil structure, with locally-produced materials.
These two combined mean I think it might be a good soil amendment in heavy clay soils, gradually transforming them to a state where drainage is good enough for a no-till system.
A very woody crop, like pigeon peas, might take so much chipping effort that biochar would allow residues to be added faster or more easily, in some cases. There are also cases where contagion might prompt people to burn ag wastes anyway, and partial pyrolysis can save some value.
Separately, I like the idea of charcoal on fields better than black plastic. I think the right vegetable binder could turn biochar into a thin coating that stays in place and helps early crops to warm up better.
Thinking about it creatively, I could see a reasonably low-labor and low-pollution way to make biochar in place, given some earth moving equipment: Fill a trench with with solids, cover almost all of that length with thin steel sheets, and seal any gaps with soil. Light a fire at one end, and put a portable chimney with a secondary air intake over that end. As the flame front moves through the trench, it will exhaust incoming oxygen, protecting the charcoal nearer to the chimney. Careful control of the air intake at the end farthest from the chimney would be good, especially as the process finished, but it wouldn't be too bad to cut the process off with a few feet of un-burned fuel remaning. It would sterilize the soil underneath it, of course, but trenching down to subsoil would help that a lot, and the initial fire wouldn't necessarily be as hot as the afterburner in the chimney. The result doesn't need to be dug in, afaik, but should probably be dosed with N somehow, which does add work.
Last, it would be interesting to see small farm equipment built to run on the pyrolysis gas and produce biochar as a by-product. Maybe something stationary like an irrigation pump would be the best thing to start with.
But I wonder about the ROI. You put in wood, time and contraptions. And it seems that the process has some pollution. And while the end result is some sequestered carbon, there is also some that is put into the air.
You mention getting heat, but I haven't seen one of these designed to bring heat indoors - it always seems rather outdoors.
As mentioned earlier: perhaps this is something that will be really great, but it's sorta hard to tell right now.
The challenge in maintaining it is the environment is incredibly active here. One thing you notice really quick is that your dogs poop disappears in a day, or less. This of course is a good thing, what is hard is keeping up with enough organic material put into your garden.
If you get into flood plains, which is where most people talk about thin soils, yes, they are thin, and very pour in nutrients.
We in Costa Rica have no less than 13 micro-climates, makes for interesting general statements for sure. We go from beaches which high temperature can hit 90 F to Chirripio which can have frost because it is 13,000 feet!
You actually get hotter up there than we do here, and of course, a lot colder.
paul wheaton wrote:
while the end result is some sequestered carbon, there is also some that is put into the air.
This is one of the places where complications end up being favorable.
It's important to note that not all of the heat released by making charcoal comes from burning, and of that, not all is from burning carbon. Part of the energy released while making carbon comes from forming H-O bonds in the water vapor produced, and also C-O bonds in the carbon dioxide produced. But some of the energy also comes from forming C-C bonds. Even pyrolysis processes that do not take in any oxygen, end up releasing energy.
Secondly, the charcoal itself is only about half of the carbon that ends up being secquestered. Charcoal ends up absorbing a significant amount of glomalin and other organic substances in its role in the soil ecosystem, and protecting them from decay.
I refer specifically to the willamette valley, sw washington and the puget trough, though I suspect many sites farther inland would display the following observable traits.
a) the best soils of our region are mollisols, results of the missoula breach washing prairie soils through the gorge and into the willamette valley and sw washington. much of the rest of the soils in this area are andisols, rich volcanic mineral soils.
b) we get lots of rain, 40+ inches, so we accumulate biomass pretty much anywhere that isnt repeated disturbed or entombed, even in places where it gets really cold, like 20 degrees farnheit (jk/...
c) anywhere else there isnt biomass is either 7500+ elevation- and thats glacierland here, except that they're melting...or its prairies, which were managed with fire.
and thats the tie to biochar.
prairies in the PNW are typically glacial scour which left rock piles and gravel laying on hardpan or bedrock.
they occur from sea level up, since the glaciers extended north from t9o (tenino, washington- just south of Olympia) - and by north I mean to germany, via santa claus's castle.
so the prairies are where the topsoil was so depleted that forest succession was radially challenged when the first people arrived. and the glaciers were scrubbing the stones, and the mammoth were eating grasses and forbes, and people were eating mammoths, and ... then it got warmer, and then it got warmer, and in like 5000 years the glaciers went away and forests started growing EVERYWHERE. except where the stone was laid bare as bare and wide enough to damn the invading forest!
but in time, even these places saw the enemy encroach, and the people looked about in wonder and and observed:
hey, if we burn this the deer will come and the oak trees on the forest margins will produce more and the sunflower and camas roots will be plentiful...so they managed the prairie with fire.
FFWD 6k years.
the prairies are still prairies. they are more alkaline than forest soils, and many forest species cannot easily 'schooner' or get a niche in the prairie community. likewise, the forbes and grass dont go to the forest much. ussually, even 100+ years after the burning ended, with about 6k years of grass and forbes ashes built up in them, the prairies soil is poor.
so will adding more carbon via charcoal (aka biochar) help?
perhaps. but heres the rub. to add more biomass, burned or unburned, you have to move it from somewhere. you wont find it in the prairies here, especially above glacial extents. In the willamette, where prairies have terribly rich soils, adding biochar still means bringing in biomass from "somewere else" , or having a onsite dedicated generator (ie, coppices, hedgerows, etc).
in any case, you have scenarios play out like this
goal: improve soil
method: remove biomass from functional and rich soils, move it, burn it,, apply it.
results: questionable, 6k year of charcoal hasn't amended this enough to grow tomatoes yet; it takes million of years for rich prairies to form. adding biomass to grow gardens in this soil is likely more labor intensive than building them where good soils exist. the guilds that grow in this environment are productive and were the mainstay of the salish and willamette cultures for 6k years. Their population was a few million before colonization, and these 'marginal' prairies played a large role in that populations stability.
method: burn it in place and grow on it
result: works great over the long run if population trends are stable and the niches produce is understood. in fact, changing the niche (a titanically proportioned notion) will change the plants and animals which inhabit the soils that builns d up in this system. So you loose a vital part of seasonal hunting and primary agricultural significance of this biotone. So the effect of a specific moment in the retreat of the glaciers was mimicked by the introduction of fire management, and the seral progression directed by climate change was forestalled culturally for 6k years. now the prairiesa re filling with schooner trees (trees that would have been killed in thefrequent, low intensity burn of the managed prairies) or houses- but thats a differnt discussion, mostly...
so the biochar method produces ist likely to produce enough benefit for the investment in this region, I suspect... at least not while im paying attention to the environment. and then we get into the chemistry- that in many cases due to soil mineral content and biochemistry, that biochar may influence increased alkalinity in our climate/soil matrix.... and even that the entire marketing scale of biochar as a solution for depleted soils is a too-large open-ended system, not a small scale energy looping system...
this is but the teaser. google it a bit from here, and enjoy:
From: Ethan G
Date: February 20, 2009 12:22:23 AM EST
Subject: [food_justice] a 2nd look at biochar: fact or fiction?
I want to apologize for my recent haste in promoting "biochar" as a climate solution on this list. I admit I was so blinded by my respect for scientist James Lovelock -- and impressed by his endorsement of biochar as "the one solution" for climate change -- that I suspended my usual skepticism against technologies that appear too good to be true. Yet looking deeper, I realize that there are good reasons to be critical of biochar and opposed to its industrial production.
Fortunately, Biofuelwatch has come out with a new paper critiquing biochar. The conclusion: "Lobbying is underway for a massive scaling up of biochar production, and yet there is little to substantiate the many proclaimed benefits. It is critical that we address this issue with caution, especially given the many dire consequences associated with any technology that involves large biomass demand and manipulation of poorly understood soil ecosystems!"
I think it is very important to understand the many ways that industrial agriculture contributes to global warming ... but in the course of advocating the very legitimate & real benefits of sustainable agriculture as a climate solution (like the Rodale Institute has been doing) we also need to be able to discern when agricultural schemes like biofuels and, now, "biochar" are likely to cause more harm --and injustice -- than good.
Biochar for Climate Change Mitigation:
Fact or Fiction?
Almuth Ernsting and Rachel Smolker, February 2009
as one of my zen tachers likes to say, menacingly, :" Don't be fooled by THE MIND!"
we use the bark, bits of wood, rotted wood from our forests, etc..for the beds and mulch...and we save the car to put on the beds as well
we have a no till system in our beds and we apply everything in deep mulches on top of the ground similar to sheet composting..
we only use the char or ashes on areas where the ph will benefit..which is most everywhere as we have acid soil here..but we don't use it on the blueberries or other acid lovers..however..we do use the wood, bark and pine needles on the blueberries.
we put the char on the asparagus this year with some dairy doo..and we couldn't believe how HUGE the asparagus plants got..the stalks were heavy and thick..
we put in some new asparagus plants this year too so we'll plan on using the char and doo on them in the spring as well.
because we burn between 30 and 40 cord of firewood we get a lot of char from it that is cleaned out when we clean out the wood ashes..we separate the unburned cinders ..or char..and use them as fertilizer in our beds.
be careful not to overuse either the char or the ashes..and also you don't really want to overuse the bark or sawdust or wood chips or rotted wood either without mixing in some other garden waste material..i try to use a lot of weeds in with ours..after we pull the weeds..layering them..and i also shred cardboard and paper and mix that in with the other wood type products..
This is by far one of the best follow up videos I found about Biochar ... awesome stuff!
MAKING BIOCHAR: with Peter Hirst of New England Biochar
That is some really excellent stuff on how biochar isn't all upsides - as some would want us to believe.
At the end, he does express concerns - in a fully qualified and appropriate way!
Great video to argue bio-char's ill-effects; I agree with a lot of what this guy says, but I think he's missing a huge point (not that I'm an expert or anything). As Pete Hirst points out in his video that I posted just above, biochar IS supposed to be inoculated with compost in a 50-50 ratio and NOT used without.
According to Pete, biochar, if used strictly by itself, does do harm to any healthy soil and can damage the soil's microbial makeup for a significant amount of time because of its ability to soak up moisture so rapidly. If mixed with compost and given a month's time to combine properties, the biochar becomes much more effective when introduced to one's soil - not that it is necessarily increasing the soil's health as much as it is improving the soil's ability to capture and hold water and nutrients thus improving its "dexterity" or "hardiness."
How did I become such a wiz? Well get this, Hirst put a phone number up on his web site www.newenglandbiochar.org, so I gave it a call expecting a secretary or something ... nope Pete picked up and talked to me about biochar and all kinds of other stuff for nearly a half hour, couldn't get him off the phone, lol.
In our conversation, he agreed that the process of pyrolysis on an industrial level is highly energy intensive, requires the use of a lot of fossil fuel to produce large amounts of biochar, and impacts the environment more negatively than positively. He brought up the method of using 2 steel drum cans to produce the substance, and again in his video he shows a highly eco-friendly way of making it, transforming it into a useful fertilizer, and explaining its positive effects when introduced to average soil. He also said that if your soil is very healthy, and you are growing food successfully then you don't need to necessarily use it at all. But if your soil is degraded and needs major help then using it properly will help significantly.
Give him a call he'll talk your ear off about it, haha!
Paul I'm gonna do my own demo in my backyard this spring to see if there are any noticeable differences - Hirst sent me a bag of 50/50 biochar/compost to let me test his product out, which he calls "Terra Codda" or the mix. Should be interesting to say the least.
As far as saving the world with this stuff with an intense production level, I can only think of Ghandi's words:
"Be the change you want to see in the world."
One thing that the writer covered that I had never considered before was that the carbon soaks up minerals which fall in the rain and normally end up leached down the river into the nearest ocean. These minerals are then accessed as needed by fungi which attach themselves to the particles of carbon. So if all that is true, then we can be catching trace minerals from the sky which normally don't stay put long enough to serve any value. Kinda makes me think I'll try it and see...
And what is better than compost: planting polyculture trees.
And better than protesting any ickiness: planting polyculture trees.
Here is what I think is better than planting a garden: planting polyculture trees.
I can think of at least one thing that is better than buying fluorescent light bulbs: planting polyculture trees.
Something that is better than riding your bike instead of driving a car: planting polyculture trees.
So, I see a lot of people putting a lot of effort into biochar and I think its value in colder climates is debatable at best. And I see a lot of good souls putting a lot of money and effort into this space when I think that money and effort would go about a hundred times further with planting polyculture trees.
Of course, I seem to always want other people to live their lives according to my standards and I should probably stop wanting that. It's probably wrong somehow. Maybe I should just be more secretive about wanting this.
First of all, it ain't bio-char until it gets a biological inoculation. The original bio-chars used compost tea or extracts to inoculate. It's just charcoal until then, and while that can add to CEC, it can cause a lock of nutrient in anything less than stellar soil...
This is an offshoot in thinking in terra preta, and the true value might be found in looking at the original terra preta sites. Thousands of years and still fertile, in areas anthropologists assumed for years were incapable of the fertility necessary of supporting large civilizations (we are finding they are wrong on both accounts). It is still dark soil, which means it is still holding carbon in the soil...
None of the other methods mentioned so far can sequester carbon on that kind of timeline. Any reintroduction of wood into soil will result in pretty complete reintroduction of it's carbon back into the atmospheric cycle in a matter of decades, dependent on type of wood. Hugelkutur is better than not reintroducing carbon at all but it does not have the millennial longevity, the open honeycomb structure that increases surface area and therefor CEC and available housing for biology.
If we are looking to increase cation exchange capacity and humus in a depleted soil in a fashion that keeps it there despite heavy precipitation, or sandy porous conditions, or quickly depleting soils like rainforest clays, there are no better tools available that this.
That said, it is a tool in a tool box, not a solution for every issue. There are issues clearly outlined here (some of the how-to vid I see out there makes me shudder; bashed together single barrel retorts belching methane and particulates into the air like a coal plant from hell). Any solution can be done badly, and someone always will. I think Lovelock latched onto this as a way to "fertilize" questionable soil and sequester carbon in a long term fashion at the same time, and I can excuse him that enthusiasm; both are truly wonderful concepts. But no tool is suitable for every solution, even bio-char... any single-tool tool box is deficient...
helpfulgardener wrote: bashed together single barrel retorts belching methane and particulates into the air like a coal plant from hell
I've made three batches, maybe a pound each, with a coffee can. I might want about as much next year, within a factor of two or so. It makes a little smoke starting up, but not as much as a campfire. Definitely a drop in the bucket compared to the diesel rigs connecting the port to the railhead a little ways south of me. It might release some hydrocarbons as I'm sealing it up, but less than I emit after a healthy meal.
I don't make very much, certainly not enough to put a dent in what's available to me for hugelkultur. I think it might be the most appropriate method for the scale I'm working at. But I'm open to a different method if it's worthwhile.
A double barrel retort can provide a much cleaner production method (the release of methane, the real Snidely Whiplash of the greenhouse gasses and a major component of our degassing process, is circumvented in a second burn) and a larger quantity than your coffee can can ( ), and can be bashed together for not too many dollars. This is a good video showing basic construction and showing the benefits of the double barrel design note the flame at the top of the stack; there's our methane!) Both the insulation and the stack speed the process.
Here's an "official" video that shows the difference; note the escaping gas OCCASIONALLY flaming, but for the most part we are dumping methane and particulate matter (the noted "thick black smoke" right into the air (Open wood burning is a notorious GHG emitter). Also note the difference in run times; the superiority of the double barrel system is pretty clear...
You could knock together another larger can, some stove insulation, and a stack from a couple of other cans or a small sheet ot metal for peanuts, Joel, and make char in a more earth friendly and efficient manner. I reccomend it...
The design shown in the video is OK, but I don't really like it. Not much of the heat of combustion seems to go toward heating the wood, or even pre-heating the intake air.
Efficiency-wise, I'm not sure how to compare, because he doesn't weigh his finished charcoal. If all the fuel he puts in the top is burned to ash, it would seem that my method makes more charcoal from a given amount of wood.
If I happen upon some appropriate containers, I'll build something that puts more of the combustion at the bottom of the system, and pulls its air intake from around the inner retort. For the amount I use my system, the manufacture and shipping of high-temperature insulation would probably pollute more over the life of the device than making do without it.
I have come around to see your point of view. I do agree that planting trees is more naturally beneficial than the burning of biochar is. (You could still use fallen branches and twigs/brush to either burn biochar or create compost.)
I heard an incredible fact today at a one day forum with John Jeavons in New Brunswick, NJ today.
If every person planted 5 trees a year for the next 5 years and raised them all to maturity, the issue of deforestation would be solved.
Don't keep secrets; speak freely. I wish what you wish as well.
Too bad our expectations are too great.
Do you own the book Candide by Voltaire? Read the last few paragraphs of the book - It's The Permie Oath
As for home production, I think double retorts show a much cleaner burn (focusing both fires to a single point for re-burn) and faster result (half the time of single retorts means less fuel and less release overall). So if planet friendly is part of your thinking (and why ARE we doing this in the first place?) I think it makes sense to build a double...
Do you own the book Candide by Voltaire? Read the last few paragraphs of the book - It's The Permie Oath
Wouldn't anything by Voltaire be in the public domain now? So you can probably find it and quote it fully here.
A Voltaire quote I recently wrote down "God is a comedian playing to an audience too afraid to laugh."
Here is the Mother Earth News article that introduces the concept of bio-char.
I am new to this. I've been skulking around the corners for a little while. My intention was to stay quiet for longer. However, this is a topic with a great deal of urgency for me.
I'll be as brief as I can and still address some of the comments made regarding biochar and its place in the permaculture toolbox.
I will be building an Adam Retort Kiln for making biochar as soon as the ground warms up. I have at least 100 tons of material currently stockpiled. This is all beetle-killed pine and budworm-killed Douglas fir. On our property there is at least another 2,000 tons of biomass standing dead. The mortality rate among the ponderosa pine is at least 85% and could get worse. This is a recipe for explosive, catastrophic wildfire. While the challenge of building the world's largest hugelkultur has appeal, I would not live that long.
Conservative estimates put the acres of forest in Montana devastated by insects (climate change) at 3 million. This is also happening from the Yukon to Mexico. This winter in this bio-region has not been - to this point - nearly severe enough to kill the bugs. We did have weather here in late September- early October that took temperatures from 80+ degrees to +2 degrees in 4 days. That hurt everything, so hopefully slowed the bugs somewhat. However, I've seen plenty of the critters still alive in some of the down logs.
In short, this landscape is undergoing rapid, profound transformation. Nothing like this has happened in recorded or traditional memory.
I first learned of biochar via The Permaculture Activist a couple of years ago in an excellent article by Kelpie Wilson. Given the burgeoning problem at that time, I was searching for ways of dealing with the situation and hopefully turning the problem into the solution. What I discovered upon doing further reading excited me enough to get my colleagues involved. I am neither the brains nor beauty of this outfit. I just get dirty.
Their research far exceeded my own in both depth and quality. Rick Freeman who's a Phd consulting forester and Gloria Flora who runs a not-for-profit devoted to public land issues now spend part of their time in biochar related work.
I am not qualified or capable of writing about the soil science. But, there is plenty of it out there. Cornell U has done some good work on biochar in temperate climate soils. The Aussies are very excited about the stuff because of the positive effects when applied to drought stressed soils. Organic farmers in my area want to try char because it holds on to phosphorous so well. Those interested can check www.biochar-international.org or biochar-us.org You can find the numerous papers and presentations that have been given at the various conferences.
As Permaculture designers we need to put our own projects, methods and tools into the context and perspective of our bio-region. This bug kill may seem to be only a problem in the mountains and ridges above Missoula, Helena, etc. But, not only is it an extreme fire hazard, when the trees go the water will follow. The feedback loop will get tighter. It effects everyone one of us in this part of the world. In order for our permaculture designs and projects to stay adaptable and resilient we need to consider and value all of the tools available to us. We carry with us to every design the same ethics and principles. However, after that things get pretty site specific and generalized absolutes become dangerous.
I just can't see hugelkultur, biochar and planting trees as being in opposition to each other. They are complimentary. In April I will be planting over 200 stems - fruit trees, nut trees and shrubs into the EFG. My planting mix includes biochar and aged bits of wood. I have a hugelkultur- surrounded by trees - that contains quite a bit of char. As soon as the kiln is operational, the garden beds will get char at the same rate as the forest test plot, 10 - 12 tons per acre. Roughly a 1/2 lb. per square foot.
Using biochar to help build soil is cutting edge. So is permaculture. The edge is where the action is and where permies belong. Will biochar do well in this shale-based soil? How will the same char at the same rate compare in the granitic soils a few miles away? What about the silt laden gravels near the river? Will some crops benefit more than others? Will char made from pine have comparable benefits to that of other feedstock? Douglas fir? Will either produce more gas and oil? These and a hundred other questions. We don't know yet - but we'll find out.
In this arid climate wood does not decay fast enough to make hugelkultur a possibility on a large (acreage) non-irrigated scale. When we first started to explore this place ten years ago, brush piles and logging debris from the 1950s were still in evidence. We have some wonderful wild currants that are growing out of 60 year old slash piles on a north slope. Very little deterioration in the dead wood has occurred. Of course, with additional water all that changes.
A few quick points and I'll get out of your hair.
I intend to capture as much heat from the kiln as I can using both water and hot air directing it toward the greenhouse.
The very first thing I am going to do with the next batch of available char is spread it in the chicken cave. I did this on a very tiny scale last year with some char from a laboratory and it seemed to have a great effect. Once the chickens tilled it in the air sweetened up because the char absorbs so much.
An obvious question about the economics. Since the pulp mill in Missoula closed there is no market based option for dealing with this dead biomass. The cost of thinning, grinding the small stuff and decking the big stuff is about $600 per acre no matter what the end use is. If I want the hazard removed from the property it would cost me a $300 tipping fee per load on a local rancher's land out in the sagebrush, plus the expense of loading and hauling - probably at least another $300 per load. Being dry, it will probably weigh about 30 tons per load. The rancher will open burn the pile - a huge bonfire. Some property owners are basically forced to do this.
Which brings us to the pollution question. I expect the kiln operation to put about 70% less crap (technical term) into the air than open burning the same material and much MUCH less than wildfire. Modifications may improve this. There are kilns which are more efficient with nearly zero emissions. They are considerably more expensive, as are the large mobile kilns with comparatively huge capacity.
To answer another obvious question: I already supply five households with firewood, have milled my own lumber for the house and will continue to mill for the rest of the construction projects. I've also stacked logs for use as landscape timbers here. I still have hundreds of tons of dead trees that need attention before the fires take it all.
If anyone is interested, PETCO and other places that sell a lot of tropical fish throw their used filter charcoal in the landfill. This stuff is packed with fish manure and ready to feed the soil if rescued from the dump. They might save it for you at the store if no one has beaten you to it.
Sorry for the length of this reply. Back to work.
You turn it into char..., in which case you just took it out of the loop for a thousand years, maybe more.
You gotta like that.
Nice post Marc. Best of luck with it all; I think the Adam retort is a good choice. How will you be inoculating? I figured the chickens are handy... good bacterial culture should set up fungal woodland soils pretty well for food crops. How much can you run through the cave a year? Considered brewing a tea as an inoculant?
In the illustration, black represents steel, brown is wood (stuff in the center is starter fuel: more can be added once the draft gets going, if the operator sees the need), and grey arrows show how I expect air & gas to flow.
The section of larger-diameter pipe that touches the main load of wood should have a reasonably good seal to the bottom of the barrel, and a gap between it and the lid of the barrel large enough that pyrolysis gasses can meet incoming air and be burned, but not so large that the charcoal continues to burn after pyrolysis finishes. I didn't illustrate this, but it might make sense to put crennelations in the top of the pipe, both to shape the flow of pyrolysis gasses for a better flame, and to gain better control of the total size of the gap.
The chimney that runs up the center can be attached to the bottom of the barrel in a way that allows good airflow, and attached to the pipe around it with a grating or with stiff wires, wich would serve to hold the starter fuel and also to hold the flame from the pyrolysis gas.
An air intake cowl is attached to the barrel lid, and can be the same diameter as the pipe below it. Aside from pre-heating intake air, it holds the initial charge of starter fuel. I could imagine fitting a choke onto the air intake, but that seems like an unnecessary complication.
Flammable insulation like straw or chaff might be added among the main charge of wood if it didn't interfere with dense packing, to improve the efficiency of the early stages of the process. If high-temperature insulation were available, I think it would help the most where the air intake cowl meets the top of the lid. The outside of the barrel could be insulated, but by the time it gets very hot, all of the wood would have begun to pyrolyze. A small depression, maybe full of ashes, dug under the center of the barrel might be worth the resulting efficiency gains.
Holes in the chimney to allow a secondary burn might be a good idea, but I don't know enough to say if the intake air would be sufficient.
How are you building your Adam retort? Did you buy plans or a license for that? I would be interested in seeing how you go about building it.
One of my partners runs a non-profit that is currently distributing Adam Retort licenses/plans. Sustainable Obtainable Solutions is providing these without charge to serious people willing to take part in a study, share information, provide samples, etc. I believe they have 4 or 5 left.
The plans are pretty clear, and now that there are some being built I believe there will be more advice, collaboration and innovation available. Someone considering the project would need to have a fairly consistent supply of feedstock to make it worth their while.
Costs for materials in the US seem to run about $1,000 - $1,500, depending mostly on builders' choice of materials. You need to figure on several days of labor for several people, a skilled mason being requisite. My own costs may be double that. I am going to have two steel baskets made that can be loaded into the kiln by machine or block and tackle and a primary stack that has a water pipe and plenum built in. ( for heating a greenhouse)
As of now there seems to be a large gap between kilns available for the small woodlot/backyard scale operation (a great thing to do!) and the much larger kilns capable of handling tons of feedstock per day. Chris Adam's design fits in that space. The Adam has a simple design and is easy to operate, having been designed for use in the less affluent areas of our world. Under normal circumstances the Adam would be a good size for this property. Now however, there are many hundreds of tons of dead feedstock here. At about a thousand pounds of feedstock per load, and 30 hours run time per load you can see that I could use a larger kiln. The prices though, of the larger kilns currently available are astronomical by comparison and quite often require chipping or pelleting of the feedstock, and much larger (more energy consumptive) support machinery.
I will keep a photographic record of the construction and - I hope - some useful notes. I'll be happy to share any and all.
I claim no expertise when it comes to the Adam Retort or biochar - I'm just the guy with the trowel and chainsaw. However, you can contact Gloria at email@example.com and get the real skinny.
Regarding the innoculation of the char, I do not have a large scale solution. On the garden scale (besides adding it to poultry bedding) I will do what others have suggested, keep an outdoor pee bucket full of char and feed beds and trees with manure tea strained through char. On a slightly larger scale I will be importing some soil mixed with cow manure from a neighbors ranch - perhaps 20 cu. yards - and I'd like to try tossing in a substantial amount of char when mixing in seaweed, bone meal etc. Also, I plan a mushroom bed using a heavy dose of char.
When it comes to application on forested ground on any kind of scale I just don't know yet. I'm still trying to figure out a means of application on sloped ground that won't lose too much char to runoff. We know it retains moisture and holds phosphorous, but what else can it do if there is a way to easily and cheaply inoculate it with some good stuff on a large scale?
There I go droning on again...
Marc Flora wrote:I'm still trying to figure out a means of application on sloped ground that won't lose too much char to runoff.
I understand ryegrass is an excellent host for mycorrhiza. Maybe it, or a similar species, would be a useful way both to grab the soil of the slope, and to encourage hyphae to make their way into the biochar.
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