My preferred method for making charcoal is to use 5 gallon paint pails with the lids. I put the wood in them and lower them into my 55 gallon burn barrel. Problem is that those steel pails are getting mighty rare. Does anyone know what industries or business still use them (instead of the plastic pails)? Or, do you have any ideas for another kind of container? I don't what to do the whole thing of creating a charcoal retort like the fancy youtube guy make. I'm not the handy and don't have the time or ambition. I just want some steel 5 gallon buckets with lids.

I resorted to purchasing metal buckets from here:   https://www.amazon.com/Vestil-PAIL-STL-RI-Handle-gallon-Capacity/dp/B0052P2GIC/   Mostly because I am chemical-phobic.

As far as a free source?   Look for companies that reclaim computer components.   DMSO is used to dissolve the plastic components.   However, most steel 5-gallon buckets are recycled, in that they are returned re-used for more DMSO.   Something like the way old Coke bottles were recycled.   So you might have to pay the deposit to take one.

How about a big stainless steel stock pot?
Harbor Freight has a set of 4 ,about 20 bucks.

William Bronson wrote: How about a big stainless steel stock pot?
Harbor Freight has a set of 4 ,about 20 bucks.

This is right up my alley. I actually had a stock pot but it turned out to be aluminum and it did not survive the 55 gallon trash barrel inferno. Do you know if these stainless pot will stand up to the heat for very long? How would you go about clamping the lids on. I used vice grips and the heat ruined the springs in the handles. I also used little c-clamps but I will need to find where to buy more of them. I only have 2.

I bought a set of those stock pots for a different purpose that does not involve any heat. They are really thin material. I have heard of people complaining about these and similar thin pots warping under use on top of a stove, so I would guess that the new 5 gallon 'paint' can would probably serve you better. It would probably hold up better and has a larger holding capacity. They do work great for my purpose as part of a water filter system. It looks like they are on sale even cheaper than when I bought them. It might be worth a try given how cheap it is, but you might want to open up the box in the store and see for yourself before buying them if you go this route.

To hold the lid on ,you could use weight. Another way would be to run pipe clamps through slots in the lid and on the lip of the pot.
Another idea is threaded rod from the bottom of the pot to through the lid,nuts and washers at both ends.

One more thing, a large metal ammo can.
Replace the rubber gasket with stove gasket.

http://www.armysurplusworld.com/product.asp?ProductID=60927


A metal tool box might work the same.

If you are making biochar, I highly recommend the pit method - much more bang for your buck and the only high tech bit is a spade/shovel for digging the hole and then collecting your biochar once it has cooled. You do need a good way of quenching the fire once you are finished loading - either (a lot of) water or possibly a sheet of roofing iron or similar to cut off the air (some sand/earth around the edges to seal it)

Steven the SkillCult guy has a good video on this method https://www.youtube.com/watch?v=I1jAo7qd_Q8

If you want higher quality charcoal, I'd recommend filling the 55 gallon barrel fitting the lid, and then ensure there are a few holes punched in one side. The holed side faces down in (again) a fire pit - and when it gets hot enough the escaping gases will add fuel to the fire. Once that process stops your charcoal is done.

Find a company that does driveway sealing in your area. They still use steel 5 gal. buckets. cleaning them can be a bit messy but you would likely get the buckets for free. Just a Thought

If your looking to reuse these containers it might be better to go with some cooking equipment. I’ve used a “can cooker” while camping with some friends. They cost more, but I imagine they would last much longer, though it is only a 4 gallon, it already has a vent. https://www.amazon.com/gp/aw/d/B0036QZ7I0/ref=mp_s_a_1_5?ie=UTF8&qid=1521923071&sr=8-5&pi=AC_SX236_SY340_QL65&dpPl=1&dpID=41V0DtiObVL&ref=plSrch

Dar Helwig wrote:

William Bronson wrote: How about a big stainless steel stock pot?
Harbor Freight has a set of 4 ,about 20 bucks.

Do you know if these stainless pot will stand up to the heat for very long?

No, they won't hold up to the heat.  I used one in my wood stove and got about 20 burns out of it before the bottom started burning though.  The rivets on the handles also melted off.  On the positive side, I just set the lid on it and the gasses escaped out from under it without letting the flame get into the charcoal.  So it worked great but didn't last.  Now I use a steam table restaurant pan with a lid.  So far so good.

Maybe this is a dumb question, but why do we need to make charcoal? Isn't charcoal making one of the telltale signs of an economic and ecological downward spiral? Could we make it in a way that utilizes the heat, carbon and other gases put off in the production process?

I make charcoal to use as charcoal (grilling and smoking), blacksmithing and biochar.  I make it in my wood stove in the fall/spring when I don't need huge fires to heat the house.   As the wood gas escapes the steam pan (or originally small SS stock pot) they burn and give their heat to the house.  So I think it's a pretty good way to get multiple yields at the same time.

Outside retorts or the pit method are better at making large quantities but then you do lose the heat.

Ben Zumeta wrote:Maybe this is a dumb question, but why do we need to make charcoal? Isn't charcoal making one of the telltale signs of an economic and ecological downward spiral? Could we make it in a way that utilizes the heat, carbon and other gases put off in the production process?

I've seen some using a retort in their wood stove, swapping in fresh loads as they heat their house along the way. I was thinking if I had a RMH and then another form of burning for say hot water, I would try to include a way to create charcoal as I'm heating the water.

Ben Zumeta wrote:Could we make it in a way that utilizes the heat, carbon and other gases put off in the production process?

That's the holy grail and someday soon enough we'll figure it out. Hopefully like electricity, cars and computers when they first came out: very expensive and only for the very rich but today enjoyed by so many. Soon bio-char enthusiasts will develop better retorts, tluds, etc that utilize all products and by-products of pyrolysis. These new units will be robust, affordable, easy to use, safe, and readily available to everyone who requires heat and wants to make charcoal.

And if you're concerned about all those emissions - research on CO2 as a power source already began a decade ago:
https://phys.org/news/2017-02-battery-recharged-carbon-dioxide.html
https://www.sciencealert.com/this-battery-runs-on-nothing-but-dissolved-co2-and-air
https://www.engadget.com/2017/02/10/co2-flow-cell-battery
It will take longer than perfect charcoal but humanity will figure that out too.

I just watched the videos recommended above, by SkillCult.

His method--which is EXACTLY a bonfire on the ground, but you turn it over and extinguish it with water when it gets down to coal--is certainly tantalizing. I'm sure it's not a perfect burn, there must be unburned parts in the center of the larger pieces of wood, and entirely burned parts in the smaller pieces of wood. But seeing him knock out what is otherwise a very labor-intensive job of many hours or days in just a matter of minutes with precisely zero equipment really does make you wonder why so many others swear by the complicated methods.

Sorry, so to bring back the relevant point. Your question was what container to use: the guy mentioned in the video uses planet earth.

Can't say if his methods make the proper thing, but if they do, it's hella faster and in greater scale than anything you can put in a can. I'm certainly going to try it: I've got ten acres to cover.

I'm doing the same thing as Mike. Steam pans, which so far seem pretty durable, but this is the first season I've used them. I used to take tin cans and crimp the rim of one to fit inside another, fill them both up and jam them together to make a canister. They never lasted more than about half a dozen burns before disintegrating.

When I put two full pans into the fire, the heat they produce as they offgas is comparable to a decent size chunk of split firewood, so I count the heat in my living space as a yield.

Each time these threads come up I keep coming back to what I see as the fundamental problem with most of these "char in a can" type methods. They are limited by the amount of wood you can put in a can, and require external fuel to do the charring. If you want a decent quantity of char, or have a large quantity of woody material that you need to dispose of, then the time and labour investment needed to use one of these systems is huge.

The cone kilns - see video below - take care of the "human" aspect of this problem in what I consider to be an excellent way.

They can make a huge volume of char in one go

You can keep adding more material to the top - which is similar to how I tend to garden in practice anyway, throwing branches and stuff on as I cut them

It takes pieces of much more variable sizes, lengths and thicknesses with minimal processing - if a piece is too long then when it has burned through you can chuck the ends back in again.

The design minimises smoke pollution by ensuring a nice clean burn

It is portable - you can literally roll it to where the work is taking place.

I went to a local fabricator today with my plans for a Kon-Tiki kiln. I want to be able to do large-ish batches, with sizable chunks like leftovers and slash from forestry harvests. I especially like the smokeless aspect, mostly since I've done a couple of burns in a half barrel to observe the flame behaviour. But in doing it this way I know I'm going to forgo the heat yield for the most part. Yeah, I can grill some steaks during the burn, and one of these days someone will come up with a heat exchanger that doesn't rob too much from the pyrolysis. The only way to really maximise yields is with a more industrial process, such as a continuous-feed retort which runs a cogeneration turbine or collects syngas to power another contraption.

Meanwhile, I'll keep doing slow and small with the steam pans. I've already filled two potato sacks since we had a cold snap last month and lots of fires already. It's a great way to just deal with things like nut shells, corn cobs, floor sweepings, sawdust and little offcuts and bark bits that accumulate. The bigger pieces will get saved up for the Kon-Tiki.

Do you have the ability to create a charcoal mound?  You'd need a little bit of clay in your soil.  https://www.youtube.com/watch?v=SjK2XlNE39Q

I love the kon-tiki kiln. Not for me, but I love it, and in a situation where I had mountains of slash or whatever to turn into biochar, and no need to heat myself, I would use one.

My long-term idea for making biochar involves the chosen profession of my much better half. She is a glassblower and engraver. The glassblowing part involves a specially designed furnace with a resting temperature of around 2000 degrees fahrenheit, and it goes up to about 2200 degrees when "cooking" the raw materials into glass. This is a process that is powered by natural gas or propane, except in the case of electric furnaces, which exist, but would require a ridiculous amount of cheap electricity to be viable.

Whatever the power source, I want to use a 55 gallon drum retort that uses the exhaust stream from the furnace to pyrolise wood and biomass into biochar. I don't know whether it will be sufficient to pass the exhaust stream around the sealed, filled drum, or if I will pass a chimney of sorts through the centre of mass, but I think this idea has merit.

Looking at the kon-tiki kiln, I was wondering what would happen if I built such a thing with the exhaust from the furnace entering the cone from the bottom into a filled cone. The pyrolisis would be largely without oxygen, as there would be that column of heat rising from the mouth of the cone, but as oxygen-free hot gasses would be supplied from the bottom, I don't know that any outside air would enter the cone, as in the video.

Granted, as it stands, that setup would offgas the woodgas to the atmosphere, so it isn't yet a complete design, just an observation.

I think one of the first furnace exhaust-based retort systems I try will be the drum setup, and my goal will be to determine if the woodgas coming out of the barrel is clean enough or can be cleaned enough to be cycled back to the furnace as fuel without compromising the quality of the glass.

I have to say, though, that the single most impressive part of the video was the water scene. I would have liked to see fine mesh and paper filters on the water outflow for the first bit of water passing through the char, but I wouldn't be concerned at all with tiny bits of that charcoal making their way into my soil.

-CK

I think I would rather have a trough style char kiln than a Kon Tiki .
Longer pieces could fit, for less prep cutting.
It could be better for ease of fabrication as well.
But I dislike the waste of the heat, etc. I don't have huge amounts of slash to diminish, so making room isn't a yield for me.
The time put in burning is important, so how cn we get more out of it?

Here is one way:





The second  of three videos, I would describe it as charcoal made inside a black oven, with wood smoke products captured as a bonus.


Here is another version:



I would want want to use the heat for baking/drying/space heating.

This video details the temperature at which the gasses coming off the char stops being steam and the  starts being fuel.
They use this fuel to pyrolysis  the fuel stock in the next retort and so on.

Hornito Biochar Kiln

If you happen to be able to view the video, that is. There is apparently some dispute over copy write.

Back on topic, a chamber can be cast from refractory cement. that will perfectly suit the inside of your wood stove.

My favorite so far is to make it in a 55 gallon drum with a removable lid.  Start the fire at the bottom, throw on more wood when the previous layer starts to turn white, put the lid on whenever i get done and put some heavy bricks on top to keep the lid sealed down. Lid also keeps the rain out if you're tryna keep it dry.

 Abe, that has a lot to recommend it.

Dar Helwig wrote:My preferred method for making charcoal is to use 5 gallon paint pails with the lids. I put the wood in them and lower them into my 55 gallon burn barrel. Problem is that those steel pails are getting mighty rare. Does anyone know what industries or business still use them (instead of the plastic pails)? Or, do you have any ideas for another kind of container? I don't what to do the whole thing of creating a charcoal retort like the fancy youtube guy make. I'm not the handy and don't have the time or ambition. I just want some steel 5 gallon buckets with lids.

What about a used water heater tank, those are made of steel.   Some people have made them from bricks and pottery:

https://www.youtube.com/watch?v=NrTaISI9fm4

Abe Coley wrote:My favorite so far is to make it in a 55 gallon drum with a removable lid.  Start the fire at the bottom, throw on more wood when the previous layer starts to turn white, put the lid on whenever i get done and put some heavy bricks on top to keep the lid sealed down. Lid also keeps the rain out if you're tryna keep it dry.

I used to use exactly that method. I found it tended  to be very smokey with the fuel we were using, because the air circulation was poor. I tried all sorts of things to mix it up, including adding air vents at the bottom etc... Th emost successful burns I had with a drum were in a drum with holes at the bottom for an air supply. Load it right to the top with dry fuel, then light the very top. The fire burns downwards through the fuel so the gasses pass through the hottest part of the fire and get burned cleanly (ish). I also found all drum based systems too small and time consuming for the quantities of brash we end up needing to clear.

My latest method involves the good old 55 gal metal drum with lid and ring. I drilled 7- 1/4" holes in the lid, filled the drum and fastened the lid on.
Set the drum on 3 8" tall concrete blocks and built a fire under the drum, next time I will raise the drum another block so I can get to the fire easier.
This turns the drum into almost a TULD, but no stack, don't stand around the drum the whole time, the fumes coming off the wood inside can be rather nasty.
I did use one year dry wood for this test run, the charcoal came out very nice  with just a little ash, I'm sure I could have set the fumes alight to stop some of their nastiness, but I was doing other stuff while the burn was going.

I think more holes might be better at getting those fumes out of the way as the wood cooks.
next burn will have 14 of the 1/4 inch holes in the lid, the ring does what it is supposed to do, keep the lid on tight.
The one problem is that you burn 12 - 16 sticks of wood for the process.
The best part, it acts like an oven and you get almost a full yield.

The thing I like most about this method is that it is simple to put together and it didn't explode, light off spontaneously, and the char was nice and "tinky".

Redhawk, did you use small pieces of wood or small logs inside the drum?  
Also would putting sand in the bottom of the barrel make the barrel last longer?

I use wood straight from the tree cutting, bark on, diameters usually range from 1/2 inch up to 5-6 inches.
I have a drying rack area where I stack all the wood I cut, my sticks are usually 3-3.5 feet long, then depending on what I'm going to use them for, they get cut to proper length at the time of use.
I cut trees for wood usually in spring and again in the fall, nothing gets used until it has aged at least a year, except for mushroom logs, those are cut and used immediately and they have their own ricking area.

I've never tried sand in the bottom of a barrel, but I would imagine that would help one last longer.