Tried a new method of making charcoal for biochar

I saw this on Youtube and thought I would give it a try.  I normally use a retort because I get better quality charcoal.  Let me clarify that statement.  I get better charcoal when I use my retort than I do when I use other methods.  That in no way means that someone else isn't making charcoal with another method that isn't as good as mine from my retort, or better than mine.  It simply means I can't do it as well.  That said, the retort does have one major drawback for me.  That is, I simply can't make as large a batch at one time as I would like.  In all likelihood I will still use my retort for making charcoal from wood chips or shavings.  I can't see a good way to do that in a pit or barrel.  For making large quantities at one time though, I wanted to explore other methods, and this one looked like it may work well, and without any work going into equipment.  This way simply uses a drum that is open on one end.  No air holes, no welding, nothing.  The flame cap is created simply by leaning the barrel over.  I gave it a try and I have to say, I'm pretty happy with the results.  I got very good charcoal except for a few brands from the last layer of wood I put on.  I used mostly cutoffs from dimensional lumber as I most often do.  I get them free from a truss factory near my house and from construction site waste.  The first time I tried it I got about 40 gals of charcoal, much more than I get from my retort.  It does still suffer from the same problem as other methods besides the retort, namely, it needs a lot of babysitting.  You can putter around and get a little done between layers of wood you throw on, but you have to add wood often enough that you can't do much in between.  Still and all though, I was happy with the amount of charcoal I got and the low amount of waste.  I'll certainly use this method again, if not exclusively.  I didn't take a lot of pictures, bt I did take one showing the amount of barrel lean and one of the fire going.  I had very little smoke making charcoal this way.  The only smoke at all if when I would throw another layer of wood on, and that could have been avoided by putting less on at a time.  All in all, I think this is a very worthwhile method and I would recommend it.

I noticed a similar thing while burning off a third of a 55-gallon drum I was using to make an oven. Just the barrel piece sitting flat on the ground with a teepee shaped campfire in it burned surprisingly well. It had those translucent, slow, wispy gassifier flames and had very little smoke after it got going and the sticks fell down. After it had burned to charcoal, flipping it over sealed it and extinguished the fire. I was shocked at how surprisingly well it did. Things don't always have to be complicated.

Jordan Holland wrote: Things don't always have to be complicated.

Yes, I agree 100%.

I find that the char from Semi-open Kilns (TM Douglas A. 2022 haha) can be very high grade if the Charista (also TM) constantly works and tamps the burn zone to exclude oxygen from the coals as soon as possible.

Immense volumes of char are possible -- and there's no reason why three barrels can't be worked simultaneously. The amount of scrap wood/brush that can be processed is bloody impressive.

Trace, how did you stop the burn? Did you quench it with water, or turn it over to suffocate it the way Jordon describes, or some other way?

I have a very nice trough style kiln, but this is very intriguing.
Jordan's point about tending multiple barrels is especially interesting.

For me barrels are harder to come by than water heaters are.
They have similar volumes but water heaters tend to be taller and narrower.
This would allow for longer stock.

Whenever I think about making char, I think about capturing the heat for some use.
Doing that is never free, it always requires extra inputs, like operator involvement, refined fuels(pellets, chips, etc), and/or increased complexity of the char making apparatus.
This method captures no heat , but it also minimizes the inputs, as it requires minimal attention, fuel refinement, and apparatus.

Jay Angler wrote:Trace, how did you stop the burn? Did you quench it with water, or turn it over to suffocate it the way Jordon describes, or some other way?

I quenched it this time.  I generally do not.  I normally just put a lid on and leave it until the next day. I quenched it this time because I chipped a lot of young tree branches for compost and I needed charcoal to add.  I didn't want to wait until the next day to build the pile, so I filled the barrel entirely with water and left it for a few hours.

William Bronson wrote:

Whenever I think about making char, I think about capturing the heat for some use.
Doing that is never free, it always requires extra inputs, like operator involvement, refined fuels(pellets, chips, etc), and/or increased complexity of the char making apparatus.

That is an area I haven't had time to explore much.  I don't like the idea of wasting all that heat, but as you said, I don't know a simple way to do anything with it.  I can only eat so many hotdogs :)

What is the purpose of leaning the barrel? Could it just be upright?

Hi Colin,

Welcome to Permies.

For making BBQ charcoal I use a barrel tipped over like that. When it's done I tip it up and put a tight fitting lid and a concrete block on top. I always keep the lid on it so it stays super dry, and one batch is enough for like 20 grillings on the BBQ.

Colin Sternagel wrote:What is the purpose of leaning the barrel? Could it just be upright?

I imagine it is to create a draft to allow the wood to receive just the right amount of oxygen to pyrolise.

With my 1/3 drum, I think the height to width ratio was just right to pyrolize the wood without burning up too fast or smoldering and smoking. It was sitting flat.

Colin Sternagel wrote:What is the purpose of leaning the barrel? Could it just be upright?

Yes, like Jordan said, it lets the right amount of oxygen in, and the part of the barrel that is over the fire seems to create the swirling motion of the gasses that feed the gas back into the fire and make a better flame cap. I don't know all that for certain, but I know I get less smoke and a cleaner burn than when I use my upright barrel with air holes at the bottom.

I love the innovation, Trace.  Retort doesn't create enough biochar so try this.  I have the same problem with retort.  So you think it makes less smoke than a TLUD? I am a little confused about adding wood. Do you just add it from time to time?  Do you end up adding more wood than you would to a straight up barrel?
Thanks,
John S
PDX OR

John Suavecito wrote:I love the innovation, Trace.  Retort doesn't create enough biochar so try this.  I have the same problem with retort.  So you think it makes less smoke than a TLUD? I am a little confused about adding wood. Do you just add it from time to time?  Do you end up adding more wood than you would to a straight up barrel?
Thanks,
John S
PDX OR

Hey John.  I definitely get less smoke than I do with my TLUD setup.  If you add wood slowly, you don't really get any smoke at all.  

As you said, I just add from time to time.  I wait until the wood that is in there is mostly coals and starting to ash, and then throw in another layer.  If you put enough to cover the old layer completely you may get a little smoke until it is burning good again.  I don't think I add more wood than I do in a straight up barrel.  I think the barrel being tilted creates a small metal "roof" that makes the gas swirl back down into the fire and burns it up better.  I just keep adding thin layers of wood until it's almost to the lip of the barrel and not much more will fit, and then I use a stick to push the barrel upright.  By then the wood is far enough up the barrel that you can add more and it gets enough air that it still burns well.  As it was for me, I was out of wood and time that day, so shortly after I stood the barrel up, I quenched it.

As a fellow enthusiast, if you get a chance to try this method, I'd love to hear your thoughts and comparison with TLUD.  You have much more experience using a TLUD than I do, so your results comparing the two are probably more meaningful then mine are.  I have used my retort probably 80% or more of the time for the last few years.  It can't be beaten for getting good results with no babysitting after the burn starts, but as you said, the amounts are simply too small for a person that needs any meaningful amount for a garden or such.

I have to admit I'm intrigued.  Do you normally use a chimney when you use a TLUD?  The tiliting "cover" is sort of like a chimney for reburning.

We are getting to the rainy, cold, dark season here, so I may have to wait until the spring to try this.  I don't burn biochar in the winter because it's impractical.

Most of what I have developed in biochar is from comments from you all that got me thinking and trying stuff.  I love it!

John S
PDX OR

John Suavecito wrote:I have to admit I'm intrigued.  Do you normally use a chimney when you use a TLUD?  The tiliting "cover" is sort of like a chimney for reburning.

We are getting to the rainy, cold, dark season here, so I may have to wait until the spring to try this.  I don't burn biochar in the winter because it's impractical.

Most of what I have developed in biochar is from comments from you all that got me thinking and trying stuff.  I love it!

John S
PDX OR

I have used a chimney.  I've also used another barrel that just had both ends cut out.  Both had air holes cut into them near the barrel with the wood in it.  I had better luck with using another barrel rather than a chimney made with stove pipe.

One more thing I like better about the tilted barrel method is that you can just keeping adding wood until you get the barrel completely, or very nearly completely full.  A TLUD with a chimney makes that difficult, so I never added more wood when using one.  A TLUD with no chimney allows you to add wood, but I got more smoke doing it that way.

Like you, I'm always trying and experimenting with this.  I'm just a tinkerer, and I post my results just for other people to look at and try or give input, not because I found the "best" way to do any of this.  I don't even think there is any best way.  Everyone's circumstances are so different and a lot of personal preference comes into play.

Trace Oswald wrote "
Like you, I'm always trying and experimenting with this.  I'm just a tinkerer, and I post my results just for other people to look at and try or give input, not because I found the "best" way to do any of this.  I don't even think there is any best way.  Everyone's circumstances are so different and a lot of personal preference comes into play."

I love this! Absolutely crucial for us to share ideas and figure out what works individually for us.

I have a rectangle shaped metal object to put the chimney on and off.  I always add more wood to my TLUD because I am in a specific sequence to make the right amount of char to put in the panels of plywood to run over.  Then my sequence goes to inoculation. Then I dig it in.  

I may end up trying the double opened barrel at some point.  I love these possibilities.

John S
PDX OR

Trace Oswald wrote:

William Bronson wrote:

Whenever I think about making char, I think about capturing the heat for some use.
Doing that is never free, it always requires extra inputs, like operator involvement, refined fuels(pellets, chips, etc), and/or increased complexity of the char making apparatus.

That is an area I haven't had time to explore much.  I don't like the idea of wasting all that heat, but as you said, I don't know a simple way to do anything with it.  I can only eat so many hotdogs :)

John Suavecito wrote:
I have to admit I'm intrigued.  Do you normally use a chimney when you use a TLUD?  The tiliting "cover" is sort of like a chimney for reburning.

We are getting to the rainy, cold, dark season here, so I may have to wait until the spring to try this.  I don't burn biochar in the winter because it's impractical.

Most of what I have developed in biochar is from comments from you all that got me thinking and trying stuff.  I love it!

John S
PDX OR

I have the same thoughts about the second bite at the apple, capturing the heat... It does involve a more complex apparatus, and also a shifting to an appropriate season? when there's a need for heat. I suppose a retort as part of the "solar dehydrator with RMH backup" would be useful in the late summer/early fall for preserving, or some sort of canning stove.
Another use could be a kiln for drying firewood, fueled by "brush" (from the same tree even?), or sawdust, or scrap. It could be a combination of solar kiln also fueled by a retort.

Proper matching of the fuel (supply and stoking) to make char = heat applied to "work" (cooking, drying, heating) and tending to those tasks if they require, would take some experience to fine tune. Heating, especially if used as supplemental heat for a space, or to add heat to a store like a water tank or mass, might be more tolerant of the amount and intensity of heat than cooking and less juggling.

Kenneth Elwell wrote:

I have the same thoughts about the second bite at the apple, capturing the heat...  

This is why I'm still putting up with only doing really small quantities in a warming tray in our wood-stove. I'm having a hard time justifying in my head doing a barrel-sized batch and not finding a good use for that heat. Coupled with the strict fire rules locally - we have summer drought and things would get *really* ugly if the area has a wild-fire go through.

That said, the idea of using the residual heat to dry our firewood has me thinking about how to manage that safely. I read recently that some woods benefit from a full 2 years of drying, for most efficient burning. However, in a wildfire zone, there is risk in having half dried wood sitting there, just waiting for that fire to go through!

I need to balance this side with the fact that biochar is known to help soils hold moisture, so more biochar means more resilient soil, which lowers fire risk!

Trace Oswald wrote: "One more thing I like better about the tilted barrel method is that you can just keeping adding wood until you get the barrel completely, or very nearly completely full.  A TLUD with a chimney makes that difficult, so I never added more wood when using one.  A TLUD with no chimney allows you to add wood, but I got more smoke doing it that way. "

This is the device that I use for removing the chimney and putting it back on. Pretty simple as you can see. It folds diagonally, so I can store it easily.  I made it so I could put the chimney on and take it off without help from my wife.  I find it useful to be able to more precisely figure out exactly how much wood to put in, so that I can get the right amount for my panels of plywood to crush and inoculation sequence.

Thanks for your post Trace.  Like keeping it simple. Had an idea though

As illustrated in my attached pic, what if a hole or few was made on the top end of the tilted bottom).
Would it help with the first part of the burn?

And for the 2nd part (when the barrel is stood upright again) the new hole is closed by the ground.
Wondering what y'all with more experience think. Thanks!

That's an interesting concept Trace. I've been considering excavating a trench for charring large logs. Now I'm thinking a slanted trench with some sort of metal cover over the deep end might work better. Seems like the same basic idea as your barrel but on a larger scale.

Aelios Kalypso wrote:Thanks for your post Trace.  Like keeping it simple. Had an idea though

As illustrated in my attached pic, what if a hole or few was made on the top end of the tilted bottom).
Would it help with the first part of the burn?

And for the 2nd part (when the barrel is stood upright again) the new hole is closed by the ground.
Wondering what y'all with more experience think. Thanks!

I think it's worth a try. I have an extra barrel, I'll try this when the weather is nice enough to start making charcoal again. Cool thought.

Mike Barkley wrote:That's an interesting concept Trace. I've been considering excavating a trench for charring large logs. Now I'm thinking a slanted trench with some sort of metal cover over the deep end might work better. Seems like the same basic idea as your barrel but on a larger scale.

If you try this I would love to see the results.

I love it that people are posting new ideas, possible improvements, new things to try.

I missed this thread previously!

This is a brilliantly simple design. I love it. I've used various processes that make a flame-cap: a hole in the ground, a long trench, a barrel cut down it's length. They all require works to some degree (digging holes, cutting barrels) - I really like that this doesn't need any of that. And to quench it you just need to put the lid on and seal it. The barrel itself is the quench!

This suits my needs really nicely. I need a portable system to take to the brash, potentially half a km away, and I have a small trailer on the back of the mower. I don't have water at the other end for quenching.

One thought - rather than stand it upright for quenching, have you considered tipping it upside down? Then all you need to do it shovel a small amount of dirt around the base to complete the seal. I've had lids on drums that don't fit brilliantly and  I would worry about air leaks standing right-way-up.

Gave this method a try. So far I've done two batches, and each time generated about %50 of the volume of the 55-gallon barrel, so approximately 30 gallons or so; I've got about 60 gallons total.

$30 for the barrel, I tilted at about 30 degrees up from the horizontal. My feedstock was anything from small sticks to 2-3" diameter pieces I cut into lengths with a chop saw. I liked this method for the ease of assembly (or no assembly for that matter,) quality of the char, and waterless quenching. Followed instructions on adding layers, letting them ash over a bit, then adding more. I will say that adding too much at a time dropped the temp and the barrel would smoke dark yellow dirty smoke until it got back up to temp. But when the barrel was full, just tip it up, put the lid on, and place a cinderblock on top.

My lid doesn't even fit that securely, so there may be some leakage during quenching, but I let it sit overnight or for two days to make sure it's out and I'm left with a big 'ol batch of charcoal. The larger pieces I plan on cooking with on my grill (another advantage of the waterless quenching method), but will likely spread the finer uninoculated char into the chicken run to be scratched in and inoculated by their manure, all the while reducing nitrogen off-gassing and smells from the coop.

All-in-all hugely successful for the amount of time and effort (an hour or so to chop the wood to size, and another hour or two to tend the fire.) I am planning on trying a trench method next with all the random branches I have lying around; I don't feel like taking the time to cut them into pieces, and can generate probably a good bit more than 30 gallons depending on the trench size. Will just have to a buy a long hose to be able to water quench the pit, but if I'm using it strictly for biochar and not grill coals the additional water shouldn't be an issue.

Thanks Trace!

Michael Cox wrote:I missed this thread previously!

This is a brilliantly simple design. I love it. I've used various processes that make a flame-cap: a hole in the ground, a long trench, a barrel cut down it's length. They all require works to some degree (digging holes, cutting barrels) - I really like that this doesn't need any of that. And to quench it you just need to put the lid on and seal it. The barrel itself is the quench!

This suits my needs really nicely. I need a portable system to take to the brash, potentially half a km away, and I have a small trailer on the back of the mower. I don't have water at the other end for quenching.

One thought - rather than stand it upright for quenching, have you considered tipping it upside down? Then all you need to do it shovel a small amount of dirt around the base to complete the seal. I've had lids on drums that don't fit brilliantly and  I would worry about air leaks standing right-way-up.

Hey Michael, sorry I didn't see this until now.  I think putting the lid on and tipping upside down would work fine.  As Luke said, even if your lid doesn't fit super tight, it will still extinguish the fire, but if you tipped it upside down, you have no worries of burning up all your charcoal.

Luke Cee wrote: Gave this method a try. So far I've done two batches, and each time generated about %50 of the volume of the 55-gallon barrel, so approximately 30 gallons or so; I've got about 60 gallons total.

$30 for the barrel, I tilted at about 30 degrees up from the horizontal. My feedstock was anything from small sticks to 2-3" diameter pieces I cut into lengths with a chop saw. I liked this method for the ease of assembly (or no assembly for that matter,) quality of the char, and waterless quenching. Followed instructions on adding layers, letting them ash over a bit, then adding more. I will say that adding too much at a time dropped the temp and the barrel would smoke dark yellow dirty smoke until it got back up to temp. But when the barrel was full, just tip it up, put the lid on, and place a cinderblock on top.

My lid doesn't even fit that securely, so there may be some leakage during quenching, but I let it sit overnight or for two days to make sure it's out and I'm left with a big 'ol batch of charcoal. The larger pieces I plan on cooking with on my grill (another advantage of the waterless quenching method), but will likely spread the finer uninoculated char into the chicken run to be scratched in and inoculated by their manure, all the while reducing nitrogen off-gassing and smells from the coop.

All-in-all hugely successful for the amount of time and effort (an hour or so to chop the wood to size, and another hour or two to tend the fire.) I am planning on trying a trench method next with all the random branches I have lying around; I don't feel like taking the time to cut them into pieces, and can generate probably a good bit more than 30 gallons depending on the trench size. Will just have to a buy a long hose to be able to water quench the pit, but if I'm using it strictly for biochar and not grill coals the additional water shouldn't be an issue.

Thanks Trace!

Luke, I'm glad to hear this worked for you.  It isn't the only way to make charcoal, but it's certainly the one I've come to rely on.