New charcoal kiln, aka "the Kursk"

Hi guys,

Mercedes is hungry for black gold and my greenhouse stove and the oildrum kiln are unable to feed it so l decided its time to boost charcoal production.

Meet my new kiln, named “the Kursk”.

This was a 2000l heating oil tank. I cut two lids out of it, welded in the heating chimneys, insulated and burryed in the ground at the edge of a hill, for easy emptying

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Wood is filled at the top, sealed, and fire built underneeth. Steam is vented of and when the wood is heated enough to release flamable gas, steam vent is closed and the gas goes in the bottom burning area, ignited and the exhaust vented trugh 4 chimneys runing trugh the wood bed.

I first filled some damp wood in and it just steamed and steame for hours and hours so l gave up at 2 in the night and put out the fire. The next day l lit again and the gas was flamable soon. When the Kursk was realy self heating, it started a chain reaction scareing the crap out of me. Allmost half a cord wood was piroliseing in there, no way back now!

I am batleing with Youtube to upload a video, see you soon!

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Wow, that looks great. The Kursk will definitely produce enough charcoal for you. The dirt sure makes a good insulator I like it. When you have time a little drawing of how you built it would be nice.
Edit: Does it empty out the bottom, where you build the fire under it?
Bob

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Ok here it is.

The reason l flared a good portion of gas trugh the steam vent is the bottom/chimneys became dangerously hot . In fact, so hot, just looking at the firepit for more thain a second was impossibly hot, with the clay walls/ground glowing red hot. Anyway, it was all over in about 2 hoors.

Now, this morning, the kiln was still hot but l opened it and looked inside.

I was sceptical at first, being used to 55gal batches and now makeing a 500gal batch, but upon opening a stone fe in the kiln produceing that butyfull highquality char “cling” sound. Indeed the charcoal is amazeing.

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Bob,

Sure hope so!

Yes it can be shoveled out from the bottom in a slide l have yet to make, that will lead to the grinder beneeth.

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Okay that was and BIG hot fire going there. Scary is right!
When cooled the char goes In to the grinder. And then a screen below it and into a hopper. Is there a road at the bottom of the bank so you can bring the charcoal up to the car? That would be cool to use the bank of the hill and the slope.
Bob

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Haha, Kristijan you never do anything in a normal way :smile: Well, I guess that’s part of why most of us are here - we don’t want to be normal. I know I don’t.

I’m amazed how fast this kiln is. I don’t know much about professional charcoal making but I know they were struggeling for a week with that old “kolmila” method.

I bet your MB will be thrilled. How far do you think one batch will take you?

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Wow Yes you had a “scary” hot flame coming off the Kursk (?). As always a shame you couldn’t put that to some use-- like heat the barn. The cows would be so happy it might double their production. Another great build by Kristijan. ( is Kursk a design or just a word that has some meaning related to this charcoal system?)TomC ( isn’t the ground frozen there?)

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Yes Bob there is a road right under. I plan to add a sifter to the grinder, do it all in one. And a big silo fot engine grade char, make my own filling station.

JO, guilty as charged. Normal behavour is for… hmm. Normal people :smile:

Well theoreticly the kiln shuld produce about 150kg in a charge. Minus the dust and all, a burn shuld be enough for about 1000km or a month.

One burn of what ever woody material a month is actualy less work thain prepareing/drying chunks for a wood gasifier.

Per instance, its hard to see on the top picture, but the wood used in this burn is about 3-5" dia logs. On the pic they look like twigs but those are some thick lumps of charcoal in the kiln!
Those are fast to prepare, and, when enough time is on hand for steaming prior to charing, require litle air drying.

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Tom, thank you for reminding, l forgot to reveal the meaning of the name.

Kursk was a famous Soviet submarine. When you look at this kiln from the road underneeth it looks juist like a submarine top that just surfaced :smile:

No worryes Tom! Better efficiancy of the gas is planed! Cows are in warm stables, no need for heat there, but l am planing to condense the exes gases flareing in the video. This way l much neaded gain wood tar for wood inpregnation and maybee eaven paveing some gravel paths l have, and wood vinegar for the plants. The rest of burnable gas will be burned for self kilning.

Ha, we have a incredibly warm winter here

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Hi Kristijan

With what did you isolate the oven?

I envy your climate :roll_eyes: dig the hot land at this season is hard to imagine here

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3 cm rorcwool. Nothing fancy.

Yes its a gift and a curse. This warm damp weather makes my winter chores dificult. Too muddy to log with the tractor, to damp air to dry the meat products, so the pigs are still waiting in the stables.

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Just wondering. When do you freaking sleep??
What is your next project to make the rest of us look bad?
Great progress

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Kristijan
You develop concretely tools of resilience for all of us, you are very inspiring (a car that rolls with the wood, a station of charcoal, a greenhouse of food autonomy, food self - sufficiency …). I really regret that we did not meet last winter. My children who have your age would certainly have earned to meet you .
If you decide one day to cross the Atlantic I can without problem welcome you.

Thierry

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Was that a video of the SpaceK rocket blasting off?

Nice ! :grinning:

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Ha, actualy l sleep a lot. Averidge 9 hours a day.
Not my intention at all to make anyone look bad, its just this site gave so much to me, l feel l must give something back. Thats for all the reports l make :smile:

Thierry, l regret we were unable to meet too. I plan to make it to Argos sometime in the future, but if you do decide to visit Europe again, you are welcome to visit and stay as long as you wish.

Jeff, pitty the camera cant show the intense heat under there. I had absolutley no idea such heat can be generated just from pirolisis gas! I was actualy afraid the Kursk wuld collaps becouse the supporting legs were glowing red hot.

Emptied the kiln today. What a feeling, never saw so much char at one place in my life :smile:


There were 3 partly chared logs at the gate, everything else was premium ringing charcoal.



filled the big bag allmost full with grinded engine grade char. Allmost a month worth of fuel fotr the car.

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yeah… the like button is getting glowing hot…

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Bob asked for a skiz

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Thanks, Kristijan,
That clears it up a bit. Might want to turn that front steam vent up and away from you! Very impressed with the result, Charcoal looks great. Did the retort survive the heat?

I wonder if this could be used for a cutting torch fuel… I bet the tar would plug up the torch and O2 would still be needed.

Could fill up a gas bag, but, in time the bag might stick together.

Thanks for the skiz.

I like the cab on your tractor. :heart_eyes:

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It actually makes perfect sense, you have perfectly contained the heat from a large quantity of wood, then release the energy in a very short timespan. The energy is at least twice, maybe 3 times enough to charcoal the wood. Some systems will use the excess heat to dry and heat other batches.

I would like to trap the retort gas for use in a miniature town gas system…

I am concerned about the lifespan of the retort if it is subject to runaway heating, but I am sure you have this in mind, and are getting practical results.

Here’s a link documenting the runaway heating.

https://www.biochar.info/biochar.CarbonZero-Experimental-Biochar-Kiln.cfml

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