514 ft^3 charcoal generator

I would first like to start off by stating that this is my first post on this forum, I have read most of the content provided by the library and looked through quite a few threads over the months that I knew this forum existed, but I would like to reinstate that most jargon, abstract key terms and nuisances are lost to me and my require a few minutes to find out what it may mean. Please be patient with me as this is my first time posting anything on a forum.

Currently the aim is to create a large scale charcoal producer, and maybe harvest the wood gas for energy production via a generator. The project will be located outside of a small woodworking shop, so an ample supply of dried scrap wood and wood chips and sawdust is available

My hope is for this thread to allow me to get some pointers from experienced individuals as to:
• How they would go about this project
• Point out any difficulties I may face along the way
• Find any flaws in my thinking or unrealistic goals
• Comment on how productive my designs may be.
• Show how to further optimize designs
• Etc

I will list out some of the resources I have at my disposal, for the benefit of anyone wondering

  • Steel container roughly 10’8” tall with 7’10” diameter ~ 514 cubic feet
  • Large tractor
  • Stick/MIG welder
  • Skills in
  •     CAD
  •     Degree in Engineering
  •     Micro-controller programming (for automation)
  •     Schematics reading (adequate at best mind you)
  • Local laser cutting workshop (for custom pieces)
  • A couple skilled workmen (for extra help)
  • Many common tools
  • Arduino Uno and Raspberry Pi processors

Some shortcomings that may come up and stall/end production
• Little to no relevant work experience
• Other responsibilities that may ebb and flow in importance

Some ideas that I have are as follows:
• Try separating synth gas into its core components to allow for better combustion/energy release but this seems to be out of my scope of abilities as I am aware
• To have airborne tars, carbon dioxide and water vapors exiting the reactor reduced, I could add a section of piping that is filled with heated charcoal for the products of the reactor to travel though, with said section of piping being fed with a constant supply of charcoal by some means

This may take some time to gather momentum but I look forward to collaborating with you all and hope that life will allow this idea to come to fruition.


Welcome to the DOW AlexanderR.
For your current direction you will find very interesting KristijanL’s largish Kurst-named Charcoal making systems.
As practice try searing for this using the magnifying glass search tool up in the top blue band bar.
That doesn’t work then go to the paper stacked tool and look in the Charcoal Gasifier topics section.
Steve Unruh


Welcome Alex. What you build depends quite a bit on what you plan to power with it. You would be better off building a simple fire and fueling something like a lawn mower engine as SteveU suggested to someone in a different thread. You will learn about the gas itself, air/fuel and getting plumbed into the engine, experimenting with water drip, ect. It’s good to go to elementary school before going to university. Have no concerns about what you post. no one is going to pick it apart.


Hello Alex, and welcome.
You have a supply of dry wood so I recommend a tlud (Top Lit Up Draft). I recommend starting small.
I started by making a camping stove. Next a three coffee can unit for producing charcoal for my barbecue, just because my neighbor gave me a bunch of apple wood. Last a 50 gallon unit to make charcoal for my 3KW gen set.
Maybe the best thing I made was an afterburner that allows me to make very little smoke.


I plan on having the wood gas being taken to a generator to help with the cost of running the wood shop, now this is a completely different can of worms, but I feel confident that the workmen that will help me are capable of integrating this as they have done such before.

The question now becomes a matter of how it will be refilled, my current idea is that it will be a simple batch process, as I can’t think of how to make it a continuous process, maybe the container can act as a reservoir for the system but I am not too familiar with wood gas generator at this point.


Pyrolysis gas coming from a charcoal kiln has a lot of impurities in it. @Matt is working on a Gasometer system to store the gas while making charcoal, but the gas will be used for utilities not an engine. You won’t have as much engine ready gas as you think it will, you would need a very large gasometer to safely store it as well to run a generator for any length of time.

I would save the gas for a hot water heater, furnace, and cook stove among other things NG would be used for, and use the charcoal as your fuel stock to power the shop.

You could cut out the middleman and make a regular wood gasifier that has a large catch container for the charcoal that it slips from the automated grate shaking. Run the Genset off of that gasifier, and any byproduct charcoal is a bonus for other engines.

Matt has also advised, at least with inverter generators, it’s best to dedicate them to charging a battery bank, and the battery bank is the real power source for standard inverters sending AC to a building.


That can be done using an air lock.

However, you don’t have experience. How can a person even get experience? Ans: by starting with the very simplest case possible. I would look at Gary Gilmore’s Simple Fire, and build one. Then maybe move to something like @KristijanL’s MBZ e230. Then perhaps a raw wood reactor.

Beware, there is something that happens to us engineer types. I call it analysis paralysis. Don’t fall into the trap of trying to really understand everything before you do anything in the shop. Just copy something someone else did and get a gut level feel for what is going on. Then go back and read.



Solid wisdom. If someone asked me to explain what exactly my truck does to make fuel I cant explain it. But I sure can build it and operate it


You will never get any thing done in building in gasification with only arm chair talking and analizing everything until it is fully understood. Better the build and learn at the same time. Oops, I made a mistake building well you just learned. Now fix it and move on.
If I am afraid to make a mistake, I need to get over it. Or I try to think things way to far out, a lot of the times. Oh guilty on that one. I am still working on that one. Drawing things out does help me a lot. I can see my mistakes on paper before I begin to build it.


I did do a rough sketch of what I had in mind let me go see if I can find it later tomorrow


Hello Alexander. Wellcome.

As others hinted, the way you set your plans is frankly unrealistic for a beginer. You think in a good direction but you got one cruicial thing wrong. The gas produced from a charcoal making kiln is NOT woodgas in the jargon, but is called pyrolisis gas. Major difference. While a wood gasifier will make gas that is free of tar from the begining, the pyrolisis gas is full of tar. This tar is virtualy imposible to fully get out as it stays in a kind of gaseous form and will only fall out of gas in a extremely turbolent enviroment. Guess where that is… on the engines valves…

Second problem is the charcoal kiln produces gas uneavenly. My charcoal kiln is about 2.5m3 so not a small one its gas producing is about as folows.
For the first 4 hours no gas is produced, just steam.
4 - 7h, gas starts to contain flamable contents but is still mainly steam.
7-10h, gas gets rich enaugh to burn but only if injected in a glowing hot fireplace of the kiln. It will not sustain a flare in the open air.

At about a 12h mark, the kiln gets in to what l call supernova state. A runaway reaction, pyrolisis kicks in and as it is a exothermic reaction, the wood breaking down makes a positive feedback loop. This part will make a absolute TONE of gas, we talk close to maybe 1m3/s. But, it will only last a couple of hours. After that, gas production drops to near zero and continues to be like that for a couple of hours.

So, if the gas isnt stored, you realisticly have maybe 3 hours max of good gas production… not worth the efford. In adition, each batch has a totaly different time stamp so you cant realy predict when those 3 hours will be.

Your best bet wuld be build a gasifier for your generator.


ok I will go work on something smaller then


I hope you haven’t been completely discouraged from doing this project. I’m in a similar position. I recently bought a plasma table, but the power supply needs 3 phase, which I don’t get out here in the sticks. So I will need to get a 50kw (or bigger) generator to run it.

Thankfully I live in sawmill country. There’s one right across the street and 6 or 7 of them within a couple of miles. They produce a lot of 1" thick edgings. Mountains of them, that they just burn. More than I could ever use.

I’d like to build some kind of large scale charcoal kiln as well. My idea is to produce charcoal for use in gasifiers, for biochar and bag and sell any excess as lump charcoal for grilling. Rather than use the off gasses from charcoal making to run an engine, I want to use those gasses to dry incoming wood. It’s still green when it comes from the mills.

Alternately I could also use the gasses to heat a retort to get a higher quality gas. But this is a project for further down the road.