Massive Biochar

I know this is going to be controversial. I'm looking forward to hopefully productive comments.

We have a major industry around here (and all across the pine-growing south) with what amounts to slash and burn agriculture. Pine plantations get tax credits, and the scale is massive. I love the idea of waste stream enterprises. I've been talking to people around here about a possible value-added process. I haven't found any evidence this has been tried which boggles my mind.

The current procedure for producing pulpwood or pine timber is that a clear-cut is accomplished. Trees are delimbed, and the trunks are loaded into trucks and taken to either a timbermill or pulpmill. The tops and slash are consolidated and burned to prepare for replanting. Often, they are transported to another location before burning due to restrictions in many counties. There is an urgency to the process because the credits are not available until the new crop of pine is planted, and pine can't compete with the typical cutover species after a few years. Shamefully typically the rows between the new trees are sprayed with glyphosate until the trees get pretty big. It's not an elegant industry, and I am not here to try to change it.

What I am thinking about doing is helping one of the companies that does the clearing set up some pretty big pit burns to try to get char from the waste products. There is nowhere near enough char to even pilot large scale remediation.

1) I know this will not be perfect char. This would be for remediation, produced cheaply, based loosely on this kind of design.
- If possible it would be used in place, and not transported at all once produced,maybe spread or incorporated.
- This would be paid for by the people who own the timber producing property in that case. It would require that we can show a return on investment over slash and burn. It would be a two year process, which is hard to sell.
- It might be worthwhile for people looking to get out of the timber industry and into other forms of production, there is little money in pine plantation right now.
-It would require inputs from off the property being cleared to make the char into biochar. I'm thinking poultry/CAFO waste and wood chips, both of which probably can be delivered for free to a site. This is to put it mildly not an organic product. It's waste stream bioremediation which is a passion of mine.

2) This is a poor conversion. I know. Maybe 30% yield based on other large pit production methods. The heat and biogas are flared.
- the current process wastes 100% of the energy, this would at least use a pretty good amount to carbonize slash.

3) This would require diesel fuel and heavy equipment. Based on my estimate for the amount of time running the machines and transporting them (most of the time they are already on site) it would still be hugely carbon sequestering. Hugely.

To give an idea of the scale, we are talking about a pilot making 100 yards of char. I'm not getting any compensation out of this.

I would be interested if any of the gurus have heard of such a pilot, if there is anyone I can learn from (I have spent hours on the internet).

I like your thinking. I live in Colorado where they take their biochar seriously. The only place I know of is Eagle Valley Green energy or some such and they have a whole plant in Gypsum Colorado that creates electricity for Holy Cross energy from the beetle kill trees that are being removed to prevent massive forest fires. Supposedly they gather from within a hundred miles only. In Western Oklahoma I have cedar trees that I need to get rid of cuz they are a huge fire hazard and invasive on the prairies. I'm interestedly following this thread.

I have posted previously about my experiments with trench production of biochar. It is very effective. The basic strategy is you keep loading more and more fuelwood on the trench as the layers beneath burn down to char. The flames above protect the already created char from burning away to nothing.  All you would need is a digger on site, and water for quenching. You might like to look at the kontiki cone kiln designs; there are plenty of youtube videos of the principle in acton.

Is the intention to keep the biochar on site, or is it for the landowner to then move offsite to use in agricultural fields etc? I'm not sure that it would do much good in the woodland itself, as woodland soils tend to already have high organic carbon contents.

Don't under estimate the time taken to load and monitor a large burn trench. It took me multiple burns to deal with brush from 1/5th of an acre of brush thinning.

Michael Cox wrote:I have posted previously about my experiments with trench production of biochar. It is very effective. The basic strategy is you keep loading more and more fuelwood on the trench as the layers beneath burn down to char. The flames above protect the already created char from burning away to nothing.  All you would need is a digger on site, and water for quenching. You might like to look at the kontiki cone kiln designs; there are plenty of youtube videos of the principle in acton.

Is the intention to keep the biochar on site, or is it for the landowner to then move offsite to use in agricultural fields etc? I'm not sure that it would do much good in the woodland itself, as woodland soils tend to already have high organic carbon contents.

Don't under estimate the time taken to load and monitor a large burn trench. It took me multiple burns to deal with brush from 1/5th of an acre of brush thinning.

Our pine plantation soils are incredibly poor unfortunately, very acidic aluminum ultisols. This is a temperate climate with plentiful rainfall, which leaches over time once there are no roots in it. My property was logged after it gave out as a tobacco farm some hundred years ago.

I am interested in something more like the pit burn in Guyana (I believe) that starts the fire after loading is complete. My experience with a one yard burn was that it wasn't safe to get anywhere near the coal bed, the radiant heat was unbelievably intense. The guy I am discussing this with will I am certain not want a loader exposed to the temps we were seeing (approaching 500F or 260C).

The idea is use the loader to dig a trench as wide as the bucket, with the dirt placed on one side. Load the pit from the other side, packing down as much as possible. Put in a chimney on one side and air intake on the other, likely steel culvert. Put the cap of dirt back on. The side with the air intake combusts more to ash, and there may be incomplete pyrolysis on the exhaust side. Such is life. I would love to see if we could do a sequential burn, where we start the with the chimney on the right as intake, and the next one over as exhaust, then open up the next one to get a draft and close down the original intake. Keep going down as long of a pit as you want. This would take some sort of temperature probe to know when to move to the next section.

We are dealing with a typical minimum clearing operation of 20 acres. They won't even talk to you for less. Kon tiki and TLUD are great. They absolutely don't scale. Hope that answers the questions.

forgot the picture!

Hopefully some input, we were discussing this project yesterday, and there are two ways of doing a big amount of char.

One is a glorified pit burn, with a linear open-air pit loaded with wood. This pit would optimally be pretty wide and pretty deep, to maximize the area that is hot but without oxygen. A second load of the wood would be prepared in a long line next to the pit (but far enough away to keep from catching). Once the inital fire is quite hot, the second load of wood would be pushed into the pit, compressing the burning material and hopefully stopping combustion in the original wood. This could even be done three times or more to maximize the volume of each burn and have the least waste. The advantage to this is more material at a time. The quench is tricky- this would involve using the dozer to push the soil in what had been the ramps onto the fire. This risks the sides of the pit caving in and makes me nervous as hell. Wetting the cap is no big deal, and the clay soil here is optimal, I have capped my test burns very easily. Once it is capped we obviously need to make sure it is well marked until it is completely out, that isn't different from a burn capped initially.

The second idea is more like char production in most of the third world, with a pit dug, laid with wood, overlaid with soil and then burned from one side to the other. My test left me very unimpressed with the final product, lots of ash in the side where the air comes in, lots of uncharred bits on the other edges, like maybe 30% for my small test burn.

Anyhow, we are going to do a larger burn based off option #1 next month. Probably just a 10'x 10'x 6' (deep) burn, which should net about 6 yards of char. We have lined up thermal imaging to check the temperature (another advantage of the open pit) and will figure out more on the quench.

TJ,

I see very little controversy is charing what would otherwise be burned.  Even if you only get a fraction of the total input, this is still much better than turning all the “waste” into smoke.  And if this activated carbon product enhances soil fertility and therefore accelerates the growth of more vegetation, then so much the better.

I think it is a great plan,

Eric

Would it not be better to chip all the limbs and tops and use that to much the areas being replanted? especially if trucking away to a burn/char site is required?
Save $$ by not using Glyphosate? + mulch the new plantings + keep the nutrients on-site?

or teach them about Hugelculture... cut swales and trenches and bury the slash, then plant the new trees in the hugels.
Maybe you could test a hugelculture as a demonstration, in a small area, to see if it would be feasible/cost effective.

Anything they'll go for has to be less expensive, make more money, or be faster, or easier than the current method.

There could be another angle, like you mention poultry manure/CAFO waste, that could be another revenue stream when combined with  the tree plantation cleanup.
Like composting manure/carcasses/offal with the chipped slash wood on the plantation? Two separate problems that could be each other's solution?

Kenneth Elwell wrote:Would it not be better to chip all the limbs and tops and use that to much the areas being replanted? especially if trucking away to a burn/char site is required?
Save $$ by not using Glyphosate? + mulch the new plantings + keep the nutrients on-site?

or teach them about Hugelculture... cut swales and trenches and bury the slash, then plant the new trees in the hugels.
Maybe you could test a hugelculture as a demonstration, in a small area, to see if it would be feasible/cost effective.

Anything they'll go for has to be less expensive, make more money, or be faster, or easier than the current method.

There could be another angle, like you mention poultry manure/CAFO waste, that could be another revenue stream when combined with  the tree plantation cleanup.
Like composting manure/carcasses/offal with the chipped slash wood on the plantation? Two separate problems that could be each other's solution?

I don't know why they do what they do with the tree plantations, and I have no exposure to people who own them (often holding companies). the people I am exposed to are purely paid to clear the brush for replanting and they don't run chippers. They just burn huge piles, if it was cost-effective they would probably chip and haul so I suspect it isn't. It would be a more uniform char and I would be into that, and require less time at temperature and less crushing at the end. My understanding is that most of the plantations have to use government-approved methods to get the tax breaks that drive the whole thing. There are a lot of built in things I can't change.

I'm trying to start there. I'm just not a purple breather by nature. There are a million better things they could do. I'm not in a position of influence. So I'm doing something rather than talking about doing something better. I have 400 meters of hugelkultur, and lots of people see them. I'd be happy to help. But that is not the discussion...

I'm still working out where the market lies. CAFO waste may not be allowed, especially if farms are organic. I think char may be exempted by itself. I'm waiting to hear from some people. First step in any business is determining the market and working toward that. I am not a skilled businessman, but most of these people I am dealing with are really starting with very limited understanding of anything more complex than a bid based on the eyeball test. My aim is to walk before we run, do a test to determine if we can make it, run metrics on what the cost was in time, fuel, depreciation, etc. Then figure out a market (I have some feelers out), and work toward that. We could always bag and sell it at big box, but I really want a short supply chain. If the tree farmers want to pay to get it converted, we could generate a price for that obviously.  

I made a picture- open pit concept, bermed on the edges with ramps for thermal protection and then as caps. Three piles in sequence.

Very interesting. Doing something suboptimal beats the hell out of talking in circles any day

Best case it works great and as time passes the process is optimized as the charcoal becomes a substantial portion of revenue...

Very interested in your results, I hope to make charcoal on a medium scale here; there are scores of acres of overly dense young regrowth of suboptimal trees that I will be clearing/thinning as time permits, and I don't want to hugel *all* of that..

I was under the impression hugel culture was not as effective in the tropics...

Awesome, Tj. I have been thinking about this, as a friend of mine on a small acreage regularly has to deal with his slash.

I was thinking about the trench idea just as you suggested, but with a slight structural modification.

What if the pit was dug out with a slightly narrower bottom, such that cross-pieces could be used to span the pit near the bottom and suspend the most of the burn pile above that dead, oxygen-free airspace? Then slash could be pushed into the pit with a loader or whatever, covered and lit, and then the charcoal would fall into the voidspace below, extinguished by the lack of oxygen. It would be desirable to mound the burn pile as much as the covering soil would allow, and I would probably add a sacrificial layer of cardboard atop the burn pile, but under the soil covering, to trap heat and help channel the exhaust towards the chimney.

This approach will probably self-quench, for the most part, too, I think.

Good to hear about this kind of remediation. Honestly, if part of the finishing process includes even just composting, and exposure to ambient fungi, it will start any necessary biochemical decomposition. If that were boosted by oxygenated compost extract and oyster mushroom slurry, I think this would be an excellent way to accelerate soil building through bioremediation.

And if, for reasons of slowing the potential spread of any remaining contamination to the rate the fungi can beat, this slash char compost or mulch is kept to functional non-edible perennials, like nitrogen-fixing bacteria hosts that drop leaf mulch, the fertility is passed on through that filter to edibles.

-CK

Guy Zindel wrote:I was under the impression hugel culture was not as effective in the tropics...

Welcome Guy.

I think that one of the reasons hugelkultur isn't as effective in the tropics sometimes is the rate of decomposition. That's why biochar, or terra preta in it's original form, is such a big deal. The char houses the beneficial soil life and nutrients and minerals that would otherwise offgas as more volatile organics decompose, and it retains its structure because the char can't break down any more.

And great as it would be in some cases for slash to be made into hugelkultur, in other cases, it might not be the right solution. Ideally, I would make hugelkultur where it was warranted, but even then I would include large quantities of biochar.

-CK

I would probably add a sacrificial layer of cardboard atop the burn pile,

Chris,
I am loving it. Another waste stream. Most cardboard is not actually recycled, but landfilled. I'm thinking of how we could get in on the top of the pile, my experience is that there are major updrafts. Might have to be several sheets thick. This is what I was hoping for on this, another few heads on possible modifications, because we are going to be trying to improve for several iterations before standardizing. Super!!

What if the pit was dug out with a slightly narrower bottom

The issue here is volume and ease of building the pit. We are hoping to get to a point where the pit can be made even numbers width of the front loader bucket. That is (we think) the least amount of time building the pit for the volume of char. The kontiki shape would be very hard to build over the angle of the dozer's pitch, if that makes sense, because removing the overburden and building the ramp/cap is the major time consumer other than prepping the wood. The volume of the triangle would be half the volume of the corresponding rectangle, but good question, and that's the reason. The other time consumer is removing the cap and char at the end, and a loader is probably the best tool for that. My preference is the deepest pit practical without weakening the walls too much, because the more top surface area, the harder to get a quench.

All good questions, and maybe I should have gone through some reasoning before.

I was thinking that stable walls would slope outwards anyways. So what if the floor of the trench was the width of the bucket, with a trench at the bottom the width of the excavator scoop? Logs or branches of appropriate length would form the structure above the scoop trench, and the pit is loaded with the front-end loader.

I also wonder if the water quench is necessary. If the cardboard layer atop the wood pile makes the pit air-tight save for the intake and the chimney, wouldn't you quench it simply by collapsing the intake at the right time? Also, wouldn't the pile collapsing under its weight and that of the soil atop the cardboard effectively smother it?

-CK

Logs or branches of appropriate length would form the structure above the scoop trench,  

Chris, we have moved from the closed pit to an open pit burn. This means we can load 3x the volume of the pit (or more) to end up with the entire pit volume full-ish of char at the end. This just means loading while it is burning, which the equipment operator apparently (!) is used to doing anyhow. He is not concerned about the stability of the soil where we are working, he said he builds pits and knows how close he can get without caving it in, even with a straight wall. I believe him, he builds pools and foundations and all manner of stuff. I am really trying to do this as a means (stacked functions yadda yadda) of development in one of the poorer counties in the state, which means you step out as much as possible and let the people you are purporting to help learn as much of the process as possible. And actually I am learning a great deal about soil structure here and the geology of the area because this dude digs it up all the time. Much of the planning is actually happening on his end at this point. I'm still providing some market assessment info and some technical input from my test burns, but hopefully I am completely out and he can run with this (with his extended family and neighbors) and I can use the data to set someone else up the same way. If we can get the price down, and do some test planting for economic data, and some soil testing for those who are interested in it (which hopefully would justify the premium) then maybe this market is millions of tons of carbon. And this is carbon, not CO2, this would be the equivalent of almost 4x the CO2!

Marco,I totally agree. I have been involved with some screwed up "sustainability" projects that were so unsustainable it made me shamed they roped me in. This has to stand economically to be viable and expand on its own merits. This is just a pilot (to get data on the material, the time and money involved, and the process used to make it). Then if and only if we can get reasonable numbers, we upscale and work on the market. I have a back of the envelope calculation that I think we are break even at about $50 a yard, but that remains to be seen, based solely on equipment costs/depreciation and paying the operators $25/hr. I can use the entire first burn myself, but I may install a garden bed for the equipment guy, hes trying to get healthy. We could get the best data from his property because I'm starting out from a much better place than he is soil-wise.

Possible markets for large amounts would be
-horse farms- horses are terrible for soil, and the char would be really helpful. And there are some very expensive ones near here.
-local landscaping supply- they sell the topsoil stripped from subdivisions, wood chips, bark and related by the yard and move a lot o product
-Upscale developments- people getting wise about the sod over clay routine, might pay a couple grand for droughtproof soil, and skip the sprinklers
-specialty farmers with high-value crops

I'm always looking for ideas if you can think of them. There is no way someone doing pine plantation (maybe $60/acre per year value) would pay for decent char. Row crops probably not.

https://youtu.be/YrZfOx_uSHY

Uses starting at the 30 minute mark.

Glad to hear operator is comfortable loading an open pit that sounds like a cost saver
It sounds like the big difference in operations is you are going FROM
light it and walk away while it burns to ash
TO
Fill the pit with char and quench

AND
You now have to truck material  OFFSITE after burning

All of which I'm sure you know but that leads me to:

So there are two things I think could be beneficial here

Include a gentle ramp when you build the pit so you can unload with a front end loader as this seems to be multi industry standard for rapid movement of material, either that or 3 walls of earth that are designed to be driven on for loading the burn,  and the "4th" side notnjaving a wall so the loader can quickly load and unload the bay.
but pit with slope sounds like simpler implementation if water table isn't a large concern

2 if you can't luck out and build this in a swamp with a simple headgate to allow rapid flooding and dousing(with nutrient rich water btw) than implement some sort of large tank system with 2 inch drainage lines so you can rapidly douse the char

Once burned and doused the good news you can probably fit 4 or more truckloads worth of raw product into 1 truck of finished product


Also, maybe you can look to produce liquid smoke for pest control as the peofi5able product and sell the char at razor thin margins to entice plantations or developer's to buy
How much more can a developer  sell a plot for if they can claim an additional 20 - 40% production  for the purchaser?

hopefully useful ideas that help:)