How to: Charcoal Retort method

[Algenco]

Ok, here's how I do it.

I use 55g and 16g barrells, but it can be scaled down to whatever you have/want

 

The 55g is the burn barrell, I use a hole saw to cut 1 1/2" holes about an inch or two apart around the bottom edge (you can see it in the last pic)

First drill a 1/4" hole in the bottom of the 16g this will be the vent hole to allow steam to escape, without it the process will take much longer

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0315.jpg

 

Next drill 3/8" holes just below the top, I put 8 holes, these will be the afterburner

remove all burrs from the holes on the inside, rinse to insure all metal particles are removed

 

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0319.jpg

 

load the retort

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0323.jpg

 

Close , make certain the retaining ring is tight

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0324.jpg

 

Place upside down in the burn barrell, now the top is on the bottom and the 3/8" holes will allow the gases to ecape and aid in the cook, load your wood, big stuff on the bottom, small on top

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0326.jpg

 

Light it from the top, this will burn slower and keep the temps a bit lower

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0327.jpg

 

once the twigs on top are burning good put the lid on the 55g, I installed a peice of heavy wall 6" stove pipe

The top will also help keep temps lower and slow the burn

http://i468.photobucket.com/albums/rr47/Algenco/Retort/SANY0330_1.jpg

 

If the wood your making charcoal with is well seasoned you should here it begin to roar as the burn reaches the bottom and shouldn't need any additional wood to complete the process

at this point you can remove the top and check on things, if it's done they'll be very little smoke/flame coming from the vent

If so it's done, remove the retort and cover the holes, let it cool.

If the holes aren't sealed off your charcoal wil burn up

Edited October 23, 2012 by Algenco

[usapyro]

Ohhhh... Nice trick putting the little hole in the top so you can tell when it's done.

 

In my first run with my barrel I think I heated my charcoal FAR too hot... I tossed the stuff into a side container. There is no charring or ash... It just got too hot for black powder use I think. Probably drove off most all of the volatiles.

 

I have a different strategy I am going to try. I am just going to drill a small hole in the retort for a quarter inch steel tube which I will stick into the retort through one of the 55g barrels vents. It will be left in for the entire burn. That will make it real easy to tell when it's done, and not require covering any holes up... I can just toss a little water on the burning coals and stop the burn dead. The other vents will be on the top of the upside down barrel and won't be getting any air to them.

 

I wonder if copper or brass tube would work... Might get too hot for them!

Edited October 23, 2012 by usapyro

[Algenco]

the little hole is very important, it allows steam to escape, without it it will take at least twice as long to cook.

After you've made a few batchs you'll be able to tell when it done by listening.

When the charcoal is cooking properly the burning gas escaping from the larger holes (now around the bottom) will make a roaring sound, when the sound stops it's usually done

[usapyro]

Steam goes upward while the gas filled with volatiles heads toward the bottom vents? That is very interesting... I would have assumed the gasses coming out of vents on the top or bottom would be about the same. Somehow in a very hot environment the moisture must somehow form a gradient and be driven away from the hotter areas of the barrel if what you say is true.

[Algenco]

gas will also go out the top but without the hole steam will be trapped, when the gases get going they'll come out every hole.

 

you want the vast majority to exit near the bottom where they'll burn off heating the retort, when it get going good it's self sustaining/regulating, as the cook near the end gas production decreases, preventing overcooking, that is if you don't have too many coals.

 

It's something you'll learn with experience, when my charcoal is done there is about an 2-3" of coals left in the barrell

 

One thing I left out, I place 3 bricks in the 55g to keep the retort off the bottom, this allow heat to get under it and keeps it up out of the coals at the end

 

I make 150-200lb of charcoal per year

[bob]

how big of chunks off wood do you use in your retort? cause in the picture they look very big but I"ve been told that they should be less then a inch by a inch and how ever long you want them

bob

[Algenco]

how big of chunks off wood do you use in your retort? cause in the picture they look very big but I"ve been told that they should be less then a inch by a inch and how ever long you want them

bob

 

I tend to load larger pieces last which will be on the bottom when the retort is in the burn barrell, the lower third of the retort will be subject to a lot more heat from the coals, it's something I've learn from experience.

those pieces are about 2" x3"

 

size isn't too important with well cured light woods, consistency is, but I found that small pieces on the bottom overcooked.

An ideal cook in my opinion will have some pieces in the center of the retort that aren't completly charred, I like it when I find a few with brown centers, I know it's going to by fast charcoal

[usapyro]

I also have a similar tactic. I place the thicker pieces of wood around the outside and the thinner toward the middle. It's hard to get all the pieces the same thickness.

 

I cooked up some C. Buckthorn charcoal with wet wood... Never again! Takes way too long... Plus, I have a suspicion that wet wood cooks more unevenly...

Edited October 24, 2012 by usapyro

[pyrojig]

Thanks Algenco for the pics and in-site on the charcoal process . It is nice to learn the little but very important details. I can appreciate this. I have been at making charcoal for many years as well, and I still am learning neat things from "OLD" guys like you . . Us young bucks have some learn'n to do. Edited October 24, 2012 by pyrojig

[RealmMaster]

This is probably the best tutorial I have ever seen!!!! and i really feel the admins should stick this topic!!!!

Gene has went above and beyond to show this process.... I think others will agree that he has presented a topic... has outlined it.. Has fully described it in such a matter that it shall help others... I propose a volt that this topic becomes a stickie or a available tutorial...

 

 

Like if you agree!!!!!

 

BTW Thank you

Algenco

 

 

FOR A FANTASTIC TUTORIAL

[Algenco]

I load the retort with thicker splits on the outside, thinner in the center and finish with thicker chunks.

By the time the charcoal gets cooking good the wood in the 55g is done to a 6" bed of coals, the gas does the rest

When it comes out all the pieces have that nice oily sheen.

I cook Paulownia 95% of the time, this method has worked best for me.

 

All wood has had the bark removed, all knots removed, dries fast

[usapyro]

Btw, I figured out one of the main reasons why cooking charcoal at lower temperature and being careful not to overcook results in a better charcoal. Different cooking temperatures result in different temperatures of inflammation.

 

"Sir Edward Thorpe

A Dictionary of Chemistry

In 5 Volumes. Vol. II

Longmans, Green, and Co. London

1916

 

Temperature of charring -- Temperature of inflammation

260o—280o -- 340o —360o

290o —350o -- 360o—370o

432o -- about 400o

1000o—1500o -- 600o—800o"

[leedrill]

hey algenco

very nice tute thanks heaps

just one question what is your method for blocking the holes {what do you use and how do you do it }

id really appreciate a simple easy method for i have made a copy of the retort above

oh and one more question how do you seal the retort lid or does it need to be air tight or just close to

i tried packing the lid bead with fibreglass and put a air nozzle from my compressor in the steam vent hole on the bottom of the retort before drilling the afterburner holes and is not very sealed could you tell me how sealed yours is and what i can get away with

kind regards

lee

[PyroJakey]

gotta give this a try thanks!

[ollie1016]

I was having to wait about 2-3 hours for a 1 gallon paint can to cook all the way tbrough. Then I thought, ill dry the wood in my oven at home! I left my wood ( willow & pine) in my oven for one week. The charcoal then cooked in about 30 minutes! I would recommend drying your wood before cooking it.

[bob]

Bump.

A week ago I finally got around to drilling the holes in my sixty liter (sixteen gallon) retort.

A day or two after I got my retort ready I cooked two batches of poplar charcoal. An hour after starting the fire the gases stopped coming from the hole in the top so I took the retort out of the barrel and pluged the holes, when it had cooled off I took the lid off and found that each batch filled the retort about two thirds full of charcoal, and 1.9 kilograms in each batch; this all seems normal to me.

Than yesterday I made a batch of spruce charcoal in the same retort, within four minutes gases were coming out of the top hole, and in just forty five minutes the gases stopped coming out, so I thought it was kind of quick but what ever, however when I took the lid off of the retort I found that it was almost right full of charcoal! And about 2.7 kilograms of charcoal.

So has anybody here experienced their wood not shrinking when it was cooked into charcoal?

bob

[Bobosan]

Unless it is extremely dry wood to start with, I have always seen a shrinkage. The sticks retain close to original shape, just shrink and warp as moisture is cooked off.

Never done a before and after weight comparison.

 

 

[LambentPyro]

How do you tell if Charcoal is overcooked?

[BrainDamage]

you are making alot of charcoal at one time do you sell it

[Bobosan]

@Lambent - I consider it overcooked if the sticks fall apart when taken from retort. They should stay similar to original shape. When dropped on a hard surface, they sound like china glass and do not break up, yet they are cooked throughout when physically broken apart. If TLUD is used on the large sticks, they overcook. TLUD best for shavings and chunks no larger than 12-19mm dia/sqr.

 

@Brain - Algenco, the OP, makes large batches and sells them occasionally. Might PM him to see if he has any. I find It's more practical and convenient to prepare and cook several batches during a charcoal production frenzy.

Edited January 27, 2014 by Bobosan

[VikingPyrotechnics]

I like spruce in the retort. It does not lose as much weight as other species.

It is available very cheaply at any hardware store. It makes relatively good BP and very nice streamer stars.

one charcoal for everything

[leedrill]

spruce is very abundant in aus too i might have to cook some up a lot of it is treated but they sell untreated stuff too

[bob]

I use spruce charcoal for stars only since I found that poplar (particularly white poplar) to be noticeably faster than spruce in black powder.

@BrainDamage, I am currently not selling charcoal, however if you want some send me a pm and we might be able to work something out.

bob

[MrB]

gas will also go out the top but without the hole steam will be trapped, when the gases get going they'll come out every hole.

The volatiles should be lighter then the steam. With the heat being the same, the only difference should be that the volatiles have to push out all the steam before it starts feeding it's own fire. I guess feeding the fire the steam, which is what you'd be doing without the top hole, could count for a lower temperature for the early part of the burn, but if that doubles the processing time... sounds like there is a lot of water to process. One of these days i'll have to test that.

 

One thing I left out, I place 3 bricks in the 55g to keep the retort off the bottom, this allow heat to get under it and keeps it up out of the coals at the end

I'm doing something similar, on a much smaller scale. Only thing is, i don't make any holes in the retort, and place it directly on the bottom. My retort is fairly massive, so it doesn't warp or reshape from the heat, but i've been placing a bit of an I-beam on top of it just to weight it down. Light the darn thing, and when the wood starts feeding the fire it's volatiles it tends to be self-sustaining. To kill the fire early, i can put a lid on the furnace, and pretty much choke it, but i prefer to let it burn out. I tend to get a few bits of coal in the center of the retort that aren't black, but brown. Snaps like coal, mills like coal, and so on. I've said i should save up enough to make a small batch of BP from those bits alone, i'm thinking there is more volatiles left in that stuff, and i want to find out if it's good, or bad.

Anyway, not having any holes, but the whole bottom of the barrel open against the bottom of the furnace, means i don't even try to close of the retort. The ashes, and the weight on top of the retort gets to create what seal it can, and so far, it's been working out ok. Of course, my only comparison is the "bucket with a single hole in the lid, placed in the BBQ" and this is a much easier method, giving me more coal, and requiring less (yes, i see the irony) coal to make the coal...

B!

[AntarcticFX]

So according to a poster prior to me; Your charcoal isn't overcooked and is just right if it drops to the floor making an almost glass like sound upon impact without breaking? How would I be able to test this with Balsa? The charcoal pieces I have finished are so light they nearly flip in the air when I drop them, so there is no sound from impact, and no breaking. It breaks into a fine dust when I apply a little bit of pressure on a piece of it while it's between my thumb / index finger and rub it.

 

Edit: I know this topic is old, but I'd hate to have created a new one when I can just ask in one that is already up pertaining to the subject.

Edited March 17, 2019 by AntarcticFX