Peterson Build Very Hot

Just finishing the Peterson Bible model. Our first burn, with bagged charcoal only, began to melt the blower at the far end of the system. I’m hoping that by introducing wood chunks, this will cool things down, but still, after running for only about 30 mins, things got too hot for my comfort. Anybody else have problems with overheating? I couldn’t find much specific to gasifier overheating on this site.

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You might check with this guy. He is apparently selling kits to make the Ben Peterson stationary gasifier:

Go to youtube (if you haven’t already done so), and search for this:

Wood Gasifier Builder’s Workshop - Part 9: Reactor Tank Cuts

It’s one of a whole series of videos that he has there.

Or, go to his channel (It is called “Victory Gasworks”:

Hopefully there’s a way to contact him there.

I wonder if you have any leaks in the system.
Did you get good gas during that time?


Maybe your blower is turned up too high or you failed to fill the reactor with charcoal to provide insulation over the fire? Perhaps you didn’t classify your charcoal pieces >1/4" < 3/4’". It only takes a little blower pulling a few inches of water column to produce good gas. If your reaction and reduction zones are not well covered with charcoal everything will over heat. If your charcoal chunks are too big the fire may climb too high.


Welcome to the DOW AndyM.
Be sure the bagged charcoal you are using is full wood hard chunk charcoal. This is often sold as “cowboy” charcoal.
The standard briquette BBQ charcoal is actually ground up woodchar-dusts; binders; and powderd up fossil coal. Soot making, way too ashy, and flows clogging for what you are trying to achieve in a wood gasifier.
And as Bruce Southerland has described you will need to hatchet the commercial bagged charcoal chunks down and sized sort them for proper layered loading.
As an intended raw wood fuel design Ben’s Book system is going to want to run HOT operated as a straight charcoal unit.
Charcoal intended units are set up to have thicker inert charcoal spaces holding the active HOT char zone from the edges. Only charcoal intended unit run super HOT at the air nozzles. So have fewer air nozzles (usually just one) with the nozzle end located in the center of the unit, away from the edges. Reverse of the Ben’s Book woodgas system.
A raw wood gasifier does do much internal heats moderation in the wood volatiles to fuel gas conversion steps. Raw wood used and a high percentage of the volatiles are actually H2O steam. Converting this to wood fuel gases sucks up a of of heat. Final gas below the grate reactions cooling to below a normal 800C. finished gas.

Only use preloaded wood charcoal to pre-charge a naked bare woodgas system.
Ran then later on real wood the needed wood char and insulative ash will self form to control the gases exchanging areas and build up layer insulate.
Takes running time to achieve this stability.

And what is your intended use for your produced fuel gasses?
IC Engine fueling?
Steve unruh


Oh I should add that another reason for a finished fuel gas to be too hot is that it is being after the grate burnt up in lower gas hearth area by an ouside let in air leak.
These are quite common in new builds. And old builds, once OK; but then ran hard developing a burning up gas air leak.

How to tell by the gas?
Will your finished gas flare burn.
Will your finished gas engine run.


I would get away from bagged “cowboy” charcoal as soon as possible because there are lots of volatiles (AKA tar) left in this kind of wood charcoal. I think it is because of lower processing temperatures. This kind of bagged commercial charcoal is sold by weight, not purity.


True. Commercial bagged whole wood “cowboy” charcoal is only a starter get-you-going alternative for those who do not in house wood stove able to make their own really good wood charcoal.
You know the folks in no-visible smokes allowed areas.
The majority actually.
An electrical generator woodgas feeding gasifier CAN be operated on a suburban lot not noticeable IF you get your operational shit together. With NO visible emissions your number 1 priority.
Screw all other idealisms.


I will go even further. The plan is to take the exhaust gasses trough a cold charcoal filter to take the last out. If it is saturated it can be burned again. This is the plan for my boiler/gasser to make it very clean and cold. Extra heatexchanger and filter behind the boiler. No smoke or smell allowed here. The charcoal can be used in a simple fire or as a mix in a woodgasifier. Good plan or to complicated thinking?

Saw the Ben gasifier too. Nice plans and complete. No designing for me, just cut and weld the steel. My fingers are itching, but first finish boiler/buffer project. Almost there.
Ben’s gasifier has proven to work very nice doesn’t it?