Making charcoal.

[Dave Shepard]

Anyone make their own charcoal? I'm thinking about building a retort to cook some hardwood scraps from the firewood processor. I have a lot of dry pine slabs to get rid of, and I think it would be cool to make use of them for something useful. 

[Don P]

I checked the 500 gallon old oil tank today from burning a whack of scrap in it Saturday. I cut the end out, lay it on its side and load it with edgings and scrap, big slabs don't do well. Then stand it up, intakes down low. I light the top and let it burn down then drop the lid on top and scoop dirt onto that... really bad drop this time it didn't land flat. Then I pile and pack dirt around the base to seal all openings and let it cool down. That is the crude direct fired method rather than a retort, I'd like to see what you come up with. I'll tip it out and screen the fines and ash out, if the dirt contaminated it all I'll call it biochar, mix them well and give it to the wife for the garden.

[mike_belben]

I did it once.  Had a bunch of carpenter ants in some red oak so i lit it and got the pile ripping then buried in dirt via bobcat.  Dug it up later.  

It worked okay but wasnt anything too special to me. I cook on dry split wood fairly often. 

[doc henderson]

I do it 2 or 3 times a year.  I like to cook over a wood fire, but also lump charcoal.  I will see if I can find pics.  I have video but have never got a you tube account set up.  I use 30 gallon oil drums with the crimp on lids.  I drill a dozen 1/8th inch holes in the bung in the middle.  place that full of hardwood in the fire ring, and burn what ever on the outside.  then watch the smoke go from white (steam) to gray (volatile gasses)  and then flame, then nothing and you are done.  let it sit a few hours and cool then open.



 

 

 

 

[doc henderson]

I noticed in the pics that two people look like they are on fire,  that rarely happens    .  but shows the flame you get in the volatile gas phase....  yes the gas from the wood in the retort.   so that all that is left is 99% or so carbon.

[peakbagger]

FYI, a lot of the gas being burnt off is Carbon Monoxide, odorless and colorless. Be careful its easy to get a dose. 

[Joe Hillmann]

I make small batches quite often.  When I burn small scraps I wait until it is mostly coals then cover the fire and choke it out. 

I have a 2 wheeled tractor that has a charcoal gasafier on it.  The bigger stuff gets saved for that.  The smaller stuff gets ground and goes into the compost pile.  Charcoal is supposed to be great at holding nutrients and water in the soil.

[doc henderson]

yes this is an outside project.  the gasses are all kinds of the sap and resins in the gas phase.  I do not claim to know the chemistry or all the components of wood, but the gasses are prob. a range of methane to propane and all the other "anes".  the solid carbon remains, and do not burn without oxygen.  the boiled off components that leave as a gas, can burn when hot, exposed to flame and oxygen outside the barrel.  If you think about a carbon filter, the carbon can interact and bind to lots of other elements.  That is why it is at the core of life as we know it.  the majority of the gasses are carbon dioxide and water vapor.  carbon monoxide itself is actually flammable as it is partially or incompletely burned fuel.  carbon dioxide (CO2) is not flammable and is therefore also considered an inert gas, used in welding.  a room full of carbon dioxide will smother a fire or a human as well for that matter.  carbon monoxide (CO) binds to hemoglobin 50 time stronger (like a magnet) than oxygen so you can smother with small amounts of CO.  Non smokers have a CO level of 0 to 5%, smokers have a CO level of 5 to 10% normally.  a level of 50% in blood is considered lethal.  newer boilers and furnaces are so efficient, that a chimney leak is less likely to make anyone sick and less likely to cause poisoning and death.  the antidote for CO poisoning is O2 in high concentration to displace the CO from the Hg.  Atmospheric O2 is about 21%, and we can give 100% O2 and effectively higher with pressure (hyperbaric chamber).

[Paul_H]

This was from a few years ago but a excellent way to make charcoal. I make it for my charcoal tractor

Reply #15

https://forestryforum.com/board/index.php?topic=81327.msg1239729#msg1239729 

[scsmith42]

I've made my own for years.  My  method is a little bit different than Doc's (but I'm going to have to try his out because it may yield better results).

In my instance, I took a 55 gallon steel drum with  a removable lid and drilled 5 holes in the bottom of it. The holes are around 2" and were drilled with a standard hole saw.



 

The drum sits on three pieces of brick that space it up a couple of inches above the ground.   In-between the brick foundation it's filled in with sand around perimeter of the drum, but with a 6" or so gap in one spot to allow air to get under the drum and up into the holes.



 





 


Once the drum is filled I'll get it started, and allow it to burn down for 30 min or so.  Then I put the lid in place, but with several inches overhanging to allow it to continue to burn.  The smoke starts off as a dark color; when it turns light gray I'll put the lid on the rest of the way, weight it closed, and block off the opening in the sand at the bottom of the drum. 



 

Voila, home made charcoal!



 

[Don P]

Paul, Scott and I are doing the same thing, direct firing the wood where Doc is indirectly "cooking" the wood in an enclosed container with the heat outside of the container. The yield is higher since he isn't consuming part of the wood to make the charcoal although the total amount of wood used is probably similar. Doc's charcoal is cleaner with less ash in with the charcoal than with direct fired. Paul's afterburner helps clean up the smoke. If I did more of this I'd get another tank and use the knuckleboom to lower it in place when it is lit, I've seen a lot of that yellowish green unburned methane cloud departing early in the burn that would ignite in the afterburner.

This is a pic of the old oil tank, just a bigger barrel;


 

[Al_Smith]

I don't really make but I do on rare occasion dig down in my slash burn site and dig it out of the ashes .It's only a couple times a year, if I'm in the mood to fire up my charcoal grill and let it burn down to coals .Takes a couple of hours burning down hickory before it's ready .I think I might have a 5 gallon bucket with a lid on full of lump charcoal and another full of briquetes .
My fire ring  in the center of my back patio is a rear rim from a 1940 John Deere A with two layers of concrete fancy bricks around and a fire brick floor .It gets so much air all that comes out is powdered  ash, no charcoal .Good for roasting hot dogs but not for much else .You could  build up the coal bed but it would take a half a day and a lot of beer and a lot wood .

[doc henderson]

the indirect fire method produces a very "clean" char and you can let it go forever, and bet nearly pure carbon.  est. 99% from what I have read.  without O2, the carbon sits in the retort.  when you no longer have flames out the top or side of the lid, you are done.  you can add sticks and get artist style charcoal.  a 30 gallon barrel will be a little over half full, when done and I have #12 paper bags I put it in and that is just the right size to go into my chimney starter for charcoal.  lump charcoal burns hotter and shorter than "kingsford".  perfect for a steak hotdog or burger.  not as good for Dutch oven hour long cooks.  we have done that with coals from a camp fire.  In scouts, I was always being asked to make sure we hade charcoal, and propane to start the charcoal over a burner.  I finally said we need to use natural materials, or we might as well stay home and cook in the kitchen.  if you use fire coals with a cast iron cooker, use less as it burns hotter.

[Machinebuilder]

 lump charcoal burns hotter and shorter than "kingsford".  perfect for a steak hotdog or burger.  not as good for Dutch oven hour long cooks. 

Its been a long time since I have burned any brickets.
Close to 20 years ago I bought a Big Green Egg smoker/grill. since then I have tried many different lump charcoals.

I have found that the species of wood use to make the charcoal significantly changes how hot and long it burns.

I currently only have 2 different ones, one is Kamodo Joes Big Block lump charcoal. It burns fast and hot, very similar to Royal Oak lump charcoal.
The other is a Gordon Food Service Mesquite Lump Charcoal. it is extremely dense and slow burning. I use it for smoking a pork shoulder or brisket.

After reading this thread I'm ready to take a 55Gdrum and try making my own again.
I tried a few years ago and failed pretty badly.

[doc henderson]

Hedge makes dense charcoal, soft maple not as dense.  oak in the middle.  the briquets have binders and even ash to slow the burn so it lasts longer.  lump light faster as well.  just a learning curve.

[Dave Shepard]

So what is the difference between species? I'm guessing just density, as they all should have the same energy by weight.

[mike_belben]

 flavor.


I dont care what you cook over hickory, youre gonna taste it.  From butts to beans to stews to syrup. 

[doc henderson]

yes, a wood that is very heavy even after dry, should yield more char by weight and BTUs.  more carbon.

[Machinebuilder]

I guess the big difference is density.

I don't use charcoal by weight, I put what I think I need in the grill and go from there.

SO If I look at it by weight I am probably using similar amounts for the same length of time.

the other difference in charcoals is the size of the chunks, I've had some look like a piece of firewood and others like dust.

IMHO the ones to avoid are made out of flooring factory scraps, they burned hot and quick.

For flavor charcoal doesn't give that much, I add chunks of wood for that.

Mike, You're in TN know everything is smoked over hickory

I prefer cherry for poultry.

[mike_belben]

Its pretty sad.. since hickory is a very prevalent tree for the state.. That the handle mills have gone which was the best money you could get for hickory.. $800/mbf last load i sold maybe 2018.  

There are charcoal plants nearby but they only buy chipped semi loads far as i know.  

Up north its a desired firewood.  In tennesse hickory is often shunned as a firewood for a reputation of melting stoves and burning too hot.  

So i just set it aside for the smoker or leave it grow most of the time.  Makes a lot of mast and shade.