The wood turbojet or something more

We need to look long and hard at this video and talk about this and its potential application to improve gasification efficiency and make higher quality gas not just for transportation but small stationary power generation, but a small bio-town gas plant.

Fluid bed gasification on a small scale above atmospheric pressure.
Think about it…
Nearly eleven years ago Doug Williams and I talk about this on the gasification archive, but all that lead to nothing. So I tinkered, and I still think there is something here. Whether it be an exhaust gas turbine section from an IC engine driving a compressor section on a mobile unit or stationary. SO inefficient but it could be fixed if we can recover and reuse the lost heat .

What we want to do is draw some of the more intense heat off the Turbine section to reduce the stress on it, recover also much as we can after the turbine and then preheat the compressed air between the compressor section and fluid bed reactor.

We want as much heat and squeeze as we can muster…
We want to only regulate heat with steam if we have to ( also made with heat stripper off the turbine section for maximum use of all our heat and to make best use of the gas water shift…

So there it is the idea all out in the open now and I will not be perusing a patent on the idea. I hope no else does because I think this could be some good for the environment and economic development is parts of the world not already stuck on a fossil fuel system
All out in the open now

An exploded view of a chrysler turbine with the regenerator on top, between the compressor and turbine section. This is exactly what we need. But I can’t make this…

A simple fluid bed gasification stage.

The problems…

Heat stress and presure on the vessel.
Refractories and insulation solutions needed.
Tyers made of alloys that will not melt Inconels 600 or 625 will work.
Dust separations and the prevention of glass/slag forming on the regenerator or internal components or pipes and turbine blades.
Regeneration, a counter flow heat exchanger systems that is able to deal with dust.


I was looking at this as well, i did a post on my thread a long time ago.

I think a better solution would be to build a pulse jet with a tesla valve to handle the air fuel mix. No exotic metals needed and no worry about gas cleanliness at least to a point. Then push a turbine with it.

I have a little turbo I thought about converting for a wood gas experiment. This dude here does an excellent job explaining how to build one. He has a couple videos well worth watching. Cool to see this video I had wondered if anyone has ever ran a turbo jet direct from wood gas.


However, in my opinion solid oxide oxide fuel cells are the better option where development efforts will be better spent. Extremely high efficiency, and will be plug and play with future EV tech coming. Much smaller and compact, with nearly silent operation, way less emissions and they produce usable water.


I was looking at that 10 years ago too. In the time I met Dutch John. I thought about everything but came back to a normal IC motor. Why? Better efficiency, up to 30% where with that turbo you will have a strugle to get to a 20%. It is a dead simple construction though.
Someone here spent 10 years on it and it is commercially available. I can send you a link if you want. Contacted him a few months ago, but there was no experience with woodgas. If the gas is clean there wouldnt be a problem.


There was a project like this . there was a very hot Catalyst . A single drop of tar got through and caused a pit on turbine blade . Project was abandoned .


Step back further and look at it not as a turbine fueled by wood… that is my whole point. This is a self driving fluid bed gasifier, but its not working correctly or the exhaust out of the back end of the turbo would be a 4 foot long blue flame instead of a lot smoke and a little flame.

In a nut shell this thing makes gas without drawing on it.
Get it ???

Gasification as we know it from Imbert runs on a vacuum.
This has limits

Forget everything…
The exhaust IS FUEL GAS if its rigged to work right.
You blow this gas into a Gasometer you regulate the output of fuel not by drawing on it under vacuum like a conventional classifier, but you regulate fuel flow output by control over the waste gate.
Then you have a gasometer full of fuel that you cab draw off for power generation or heating just like a town gas plant using conventional town gas cleaning and distribution, but at a smaller scale.

The problem in the video is no regeneration of heat. If that heat could be recycled steam for a water gas shift I think it would produce more fuel from the turbine end than the compressor end us using to pressurize it. ( not this is not an over unity machine, this is a fuel conversion reactor that uses the heat from its own operation to drive the process…

I have picked away at this for 2 years but I don’t have the resources to crack it.
I know it can work…
I an trying to plant some seeds here and hope that someone smarter than me or better equipment than me can make it work.

Maybe I the fluid bed section needs to be much smaller and a continues fuel feed system with a large centrifuge to separate gas from solids is the solution. I don’t have a solution so I throwing this to the wind and see if it can be made to work.

I have deep reservations that a person or profit minded group will run with it and make money off it at the expense of people who really need a new idea to make fuel from biomass. Most of you guys are not so much interested in money as you are about making things that work. This is scalable too! An Imbert has limits to its size before you just can’t draw on it to effectively make good consistent gas. This idea of mine does not have that problem because its a fluid bed you just keep increasing the heat and pressure to overcome fluid flow losses…
Of course there are limits but I don’t know where they are.

I have obsessed over this for two years and its time for me to walk away now.
Ya I even ramble like an obsessed man trying to explain it… Not healthy HA HA.
Wife says too much time puttering not enough time living.

2 Likes Is one.

The one I was talking about is this one They work with stock carturbo s as basis. Compr and exhaust wheels are matched, not stock for ice.

I had the same obsession but let it go. No time. Easier and better efficiency with a stock ice. You have to go real big for better performance.

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I don’t think I have made myself clear so I made a crude block function drawing this morning here with my coffee.

Gets kind of blurry towards the upper right but that’s a badly drawn gasometer with three arrows that indicate potential uses for the clean cool gas for heating cooking or power generation.

Maybe the whole assembly could be shrunk down to fit int he bed of a truck I am not so sure about that.

There is more to it but this is a basic idea.
The dust load would require more specific gas cleaning ( maybe a centrifuge stage built directly into the fluid bed gasifire to keep the dust out of the heat Regen and turbine section of the turbo…

The waste gate must be tied to the gasometer to increase and decrease gas flow as required…

A lube pump needs to be powered.
the steam generator needs to be tuned to match the amount required to control the reaction…

As a fuel source I tried to build a fluid bed gasifire that used a fine mixture of bone dry partly torrified wood and biomass with recycled slip char from another down draft.
Slagging is a huge issue I can’t solve.

Control of slag and dust are huge issues with a fluid bed but the upside is the no fuel feed or bridging issues and its not bothered at all by long chips as long as you can auger it in.

At this point I give up, like a said.
Maybe the next move is to go back to a conventional cross draft Charcoal gasifier and get the kinks out of the rest of the system before I try and build another fluid bed.

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I am putting out there in the public domain one more simpler direction. Another one of my nice coffee table cocktail napkin block diagrams. With the price of small turbocharges as low as they are now this might be a more easily built mid step project.

The turbo uses a very conventional engine exhaust driven turbine, but this time the compressor wheel is only pressurizing the gasification unit. This unit is a conventional Imbert down draft. Again the goal is to increase pressure in the gasifcation unit to increase efficiency and temperatures.

The goal is more heat recycled in the regernators ( heat exchangers ) because we want to conserve energy and increase gas output ( with less nitrogen dilution ). Richer gas off biomass without tar. The goal eliminate the cooler or at least greatly the stage we need under the current suction based systems.

Maybe green wood chunks have enough moister in them to skip the steam injection of a charcoal unit to prevent a melt down…

Without the restrictions in place by drawing a gasifier under vacuum we can recycle heat and drive the system temperatures up without the problems other systems suffer with the air thinning out. Also the hearth and tuyers diameters can shrink further concentrating the heat for maximum tar cracking and water gas shift.

This is probably the simplest and fastest way to boosted gas generator work. I know this idea is way out there but think about it. We are dealing with an endothermic process to make gas out of a solid. Its all heat driven by the combustion of our primary fuel so why not try and improve the process by conserving heat and running under pressure?
Its just a logical next step…

It will eliminate the power loss under suction systems, increase fuel efficiency and I have no doubt produce low emission because we will burn purer and more energy dense producer gas



Hi Wallace, if you have the system pressurized when running the engine going down the road, at what bars will it be at? The hopper pop off lid will have to be able to handle the pressure and still be able to operate if needed. Up under the hood we also have pop off valves. I can see how this will work. I must be not seeing something here. Everything on the gasifer will have to be solid welded with no rubber fittings.
If you let off the acceleration the turbo has a pop off valve set at a curtain bars this is adjustable.

Well I guess about one, I don’t know what would be ideal.

In order to keep a fluid bed in motion I needed about 1 bar, that’s also an easy to achieve amount of boost from a regular turbo. A pop off valve would be as close to the compressor outlet as possible. So Ideally you have 14 pounds of boost and that what you would set the pop off at. The goal is to keep the boost on from idle to full power and maintain that 14 Psi. If you go back to my first drawing you see the gasometer that was there to provide a reservoir and keep the pressure at some level in the 11" of water range so a conventional gas flow demand meter cold feed a carb more normal gas carb or appliances designed to run of natural gas.

I never give much thought to driving on a system like this, I think of stationary applications. That’s why my gasifire had that rod on them to the engines to provide some vibration for better fuel flow. For a mobile application all kinds of things would have to be tried and considered, but I don’t think 1 bar of pressure creates much of a structural problem.

There are still going to have to be bursting disks or pop off valves in the gas handling system in case of an accidental internal " pop ". The same kinds of lids and seals will work just with a lot closer attention to leaks. In hind sight, leaks would be very bad for this on a vehicle with all that plumbing running around, in and under the car. Like I said my interest is a lot more in stationary applications and power generation.

Think about how much power your loosing on the end of things pulling on a gasifire at full power? if you could just maintain things at atmospheric pressure and like I said make better gas you might not have to put your foot to the floor in the first place. The worries about the turbo over spooling and causing a pressure surge when you back off are much less than if you were using the turbo to draw on a gasifire.

Just sitting here thinking…
Even if you have to draw on the gasifire at lower power levels once you start to make boost and increase pressure you are effectively making the system behave like the hearth size is increasing and the twyers are getting larger. In effect the turn down ration has been increases by using boost to gasify under pressure.


I remember when Nye first built NT/6. It was shown on a DYI-gas turbine yahoo group I was on - sheesh - 21 or so years ago.
The fuel was cordwood. To fill with a fuel charge, the lid of the pressure vessel used as a combustion chamber is unbolted and the wood packed in. A fire lit on top of the fuel charge and then the lid put back in place and bolted down. Compressed air is used to spin the turbocharger which blows down upon the fuel embers - causing them to burn - thus heating the charge air causing it to expand - and exiting through the turbo - driving the exhaust side of the turbo.
The process is self sustaining until the fuel is consumed to the point where it no longer produces sufficient heat for air expansion to drive the turbine. He had thought that possibly the turbo could be coupled to an electric generator to provide electric power in the jungle using minimally processed biomass fuel. I don’t think he ever actually made a self contained unit out of it. As demonstrated - the turbo requires an electric motor driven external oil pump to supply oil for the turbocharger’s hydrodynamic bearings.
The horribly high operating rpm of the turbocharger makes obtaining shaft power from the turbocharger difficult.
A second problem is the high velocity of the air supply blows ash and fine ember out through the exhaust of the combustor and through the turbine. This material is damaging to the turbine. Filtering would have to be done carefully as any cooling of the combustor’s exhaust would reduce the already poor fuel economy.
I had a concept of a traction drive I thought could be utilized to get a shaft drive from such a turbine
but life got in the way and I never worked with it.

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Yes, that one kept me busy for some time too. But you can relax, the thermodynamics of a small turbo are bad compared to a IC engine. You have to go really big like a powerplant to gain something. Apart from the problem to rev down to usable revs. I love the simplicity of it. There is a company here just around the corner that took up on this and sell gensets based on the idea. They use stock car turbo’s but change the matching of the weels. It took them ten years to develop and still efficiency is under 20%.

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