Charcoal Gasifier for Generator

I am working along on my V-10 project.

But it has recently come to my attention that I should also consider building a gasifier to run a generator to charge my battery bank when solar charging is insufficient.

I notice that many people build charcoal gasifiers to power smaller engines.

Is it practical to use a WK style gasifier to power a medium sized generator (say 5000 watts).

Could the same gassifier design be used, simply with a smaller restriction plate?

Or would the whole thing need to be down-sized?

Also, I am assuming that I would need some kind of hopper shaker for a stationary application.

Would there be any other design differences?

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Good morning Kyle.

I think one of the negatives of a charcoal gasifier is the expense of the fuel ( time making the char and possible wasted energy ) . In your case the v-10 will be producing char as a byproduct of the operation. Also I think a charcoal gasifier would be simpler to operate compared to the wood gasifier and should be a benefit running unattended .

Just my two cents :relaxed:


I second what Wayne said. Using your byproduct from the big gasifier would probably be ideal for a stationary unit.
I made a miniWK with a 6" firetube that I was hoping to have pulled out of the snow by now.
It works well while in motion but I need to set up a shaker when it’s stationary.
Last year in Argos, Gary Gilmore hooked his charcoal gasifier up to my set up and it ran all day.


Definitely practical to downsize the WK. Several folks here have done it with good results. You can also run the generator right off your V10 unit, once it’s all warmed up. It will work for awhile but eventually you’ll lose temperature and stop making enough gas. Running the truck some will shake things up and warm it right back up again.

I intend to experiment with reducing both the firetube diameter and the choke plate with removable inserts, to be able to run a variety of engine sizes on the same gasifier. We’ll see how well this works in practice.


Thanks for the input fellas.

To be honest, I haven’t paid much attention to the “charcoal” side of things.

But I can sure see where that might be best way to go for a small gasifier which is used irregularly (but urgently) to recharge the battery bank.

I have spent a little time looking at the charcoal threads.

I have just about talked myself into trying a Gilmore/Simple-Fire style charcoal gasifier.

I notice that Gary mentions having posted some plans in the file area, but I guess that was on the old website. Where can I find plans now?

Also, I notice Gary mentions his method of making charcoal several times, and other people refer to it, but I can’t seem to find the thread that tells me how to do it. Can someone point me in the right direction? I am just looking for a quick and simple way to make some charcoal for testing purposes at this point.

Also, since I am leaning towards a charcoal gasifier for this project, it is OK with me if Chris wants to move this thread over to the charcoal section and retitle it appropriately.

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Here are the plans, Not sure about his charcoal making, might check his channel on youtube.
Ok found video’s


Welcome to the dark side…


Thanks Andy.

Still looking for more detail on how the gasifier is built.

I have read the simple fire thread and think I have the general idea, but I am wondering if there is a more detailed build video of the current design?

EDIT: Whoops. I missed the link to the plans that you posted. I think that answers my question.


Good day for all of you. This how we make charcoal in our farm. We use this system for BIOCHAR. Hope it helps.

It´s very simple and all you have to do is lite it and leave it for the night. Next day, you have BIOCHAR witch leaves no tars in the reactor system.



I may be missing something, but it appears that in Gary’s retort setup, the outer barrel is mainly serving as a support structure, and doesn’t play an active role. Is this correct?

In other words, if the support ring for the inner barrel was sealed at the bottom, and the chimney mated directly to the inner barrel, the outer barrel would not be needed?

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The outer casing insulates probably the inner reactor.
coal wood conversion reaction should be improved , I think !

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The inner drum is the retort reactor, and, at the bottom, it has slice channels and the gases escape from the reactor by the bottom and ignite. I´ll take pictures and the upload details of my system. I´ll try to do that tomorow.


It will be interesting to see the details of Abner’s retort. It sounds like the more conventional type in which the feed-stock is in a completely enclosed container (except for vent holes, normally at the bottom, for escaping gasses) and the fire is built around the inner container.

I was surprised by Gary’s design, and also by the “continuous feed” concrete hopper design, since these are open at the top and are fired directly. I imagine that making good charcoal in these requires good timing (capping off the charcoal at the right time).

Anyway, I am going to try a design similar to Gary’s. However, I am going to have to modify it somewhat so that I can just use the materials on hand.

As I commented before, it appears to me that the outer barrel is mainly providing structural support in that design, and I intend to eliminate it.

Here is what I have in mind, unless some of you more knowledgeable people tell me it won’t work.

I intend to use a single 55 gallon drum to hold the feed-stock.

I will put small slits in the bottom of the barrel.

I will cut the bottom off another 55 gal drum, along with 4" to 6" of sidewall.

I will weld this “second bottom” to the bottom of the first barrel, airtight.

I will put a 2" hole through the sidewall of the new section of barrel, and insert a 2" pipe through it, and into the space between the “new bottom” and the “slitted bottom.” This will provide the restricted air supply. I will make the penetration through the sidewall airtight, and put a valve on the pipe so that I can close off the air.

I will fill the 55 gallon barrel nearly full with wood, then build a fire on top of the wood.

I will place a lid with a 12"-14" hole in the middle on the barrel.

I will place a chimney over the hole (probably 48" high, and rolled from a piece of sheet metal).

After the charcoal is ready, I will remove the chimney and hole-lid, replace it with an airtight lid, and close the air intake valve, making the entire assembly airtight. I will let it cool for 24 hours, then see what I’ve got.

Unless I have missed something, this will preserve the essential features of Gary’s design while dispensing with the outer barrel.


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OK Kyle, I think you are complicating your life, tomorrow I´ll take some detailed pictures of my systems and upload them. The good thing of my system is that you light it up and you go to sleep, next morning you have nice biochar for the reactor or what ever you want to use it for. At the moment we are building a giant one and I mean giant!!! ( 1x1x2 meters) for a total capacity of 2000 liters (volume). I have a simple drawing of it but next week I´ll have piictures.

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Thanks Abner.

A simple drawing or description would be fine if you don’t have pictures.

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I think the outer barrel also acts as insulation and that should be replaced somehow.

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Good point Brian.

I did think about that.

Looking at the design, I don’t see that the outer barrel would be holding much heat. But, it might be holding enough to make a difference???

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if you want to maintain that insulation kyle you could wrap the inside of the barrel with a cut down barrel skin with the ridges offset. It would give you a 1 inch offset. I’ve thought of this one, never done it…


I think it would reduce a lot of convective losses (“wind chill”) from either actual breeze, or the hot generator causing an updraft.

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I also have a double barrel design like Gary’s. My inner barrel is a 30 gallon galvanized garbage can with air holes on the bottom and its own lid. The outer barrel is a 55 gal drum which has two covers; one with a chimney and secondary air holes and the other airtight with a clamping ring. My inlet air at the bottom is like you were explaining - a 2 inch pipe with a valve. What I found that makes a huge difference is the rockwool batts that I fitted in the space between the 2 barrels. That keeps the inner barrel much hotter and cooks faster also. Before that I always seemed to have some uncooked brands but not after the insulation. When I hold a mirror at the air inlet and see glowing light in there, I shut the valve off, take the chimney off, put on the galvanized lid and then the clamping lid.
I tried it both ways before and after insulation and it makes a big difference so what I am trying to say is that you might lose too much heat with only a single barrel.
You mentioned my (cone) concrete hopper retort and that works super good for small branches and twigs bit not so good for larger pieces of wood as that also is single layer metal and loses too much of the heat it takes to cook the wood properly. I wanna try Abners method too.