Toyota Running On Producer Gas
Bruce Jackson, Abu Graib, Iraq, September 2005
" I will make a prediction. I believe that I can make a truck run down the road on producer gas cheaper and with less hassle then with Biodiesel. I predict others in my position will be able to do the same as well." BPJ Sept 19, 2005
2000 cc Toyota With Gasifier On Back Video Sep 2005: It's running On Producer Gas! (7MB)
Video Sep 10: It's Running Strong (5 MB)
Email from the Shop:
Sep 10 What A Beautful Day
Doug, Tom, list,
Hi, and the best to all of you.
Today was the best run ever. I got the Toyota running so well that I even drove it. I loaded the engine down just off idle by trying to drive away from a standing start in THIRD GEAR. The old bird didn't stall either.
I was impressed with the power available and the throttle response. This was the first time I really saw some serious potential for using this as a stationary generator engine cogen outfit.
Imagine a 100lb propane cylinder (do the metric folks measure their propane by kilograms?) with the cone shaped end cut off and a 55 gallon drum bolted on top.
I tried to follow the pioneer class drawing you provided. (thanks, without it I would not have gotten
anywhere) I converted the measurements over to inches.
I discovered that I could not find a smaller throat than the 5.5 inch pipe that I used.
I welded pieces of 5/8" rod radially around a large nut. I used all thread coming up through the bottom of the propane tank and screwed it into the large nut.
This is my grate.
The throat is welded to a round plate that is welded into the propane tank.
The only things that are out of spec are the throat, propane tank, and the 55 gallon drum. I know this sounds like the whole machine but not really. The oxidation lobe should be high enough off the throat.
There should be enough lip on the throat so as to allow char to build up around it and insulate it.
So there is no slope from the hopper (55gallon drum) into the oxidation zone which is the upper portion of the propane tank.
Tuyeres are some pieces of pipe that I found. Size? I dunno. I found that if I placed four together they were nearly the size of the diameter of the carburetor throat. So I figured air into the gas producer should be equal to the gas going into the engine. Just a really junkyard kind of rough guess.
I used metal flex exhaust pipe out of the propane tank and into the filter barrel. I bolted a used airfilter from a big diesel onto the filter barrel lid. The gas is introduced into the bottom of the filter barrel below a grate. Above the grate is a pile of sawdust and above the dust is the diesel air filter. The gas goes out the filter barrel where it hits a tee. Here the gas picks up its air and from there a 10ft piece of plastic flex pipe (sump pump
hose) into the engine.
I hope you are not too disappointed that I didn't follow your plans to the letter. I just couldn't do it. We simply don't have enough junk around here to build it exactly to spec. The sad thing is that the army can't get good stuff to actually build their real projects with.
Todays run was the best ever and the longest. I shut the engine off because the engine got hot. I have no radiator cap so it boils over and we just pour in more water but finally we (me and the inevitable audience) got bored and shut it off. Imagine making producer gas until you got tired of it.
Alright, I now believe that the throat might not be to spec but it isn't the determining factor in the failure of this gasifier. I am convinced that the fuel is channeling. Prior to the run this morning, I removed the hopper lid and carefully packed the throat with fuel, and then the oxidation zone then the hopper.
And yes, once lite, the gasifier produced a good stream of gas at switch over (the sweet spot). I also used all four tuyeres this time. Before I blocked two off, in a attempt to increase the air velocity into the oxidation zone.
I shut down the engine and blocked the tuyeres, and intake air. I went for lunch and came back for an afternoon session. I found that the producer tuyeres would glow white hot but the engine just stalled at switch over. Clearly, I was producing some good quality carbon dioxide. The point is, I tried to refire with out rearranging the fuel in the hopper again. Channeling, or what ever. Its a fuel thing.
Now if you've read this far you understand that I have a one track mind and nothing better to do than look at the prison walls. I am actually interested in this but there are things from chemistry class that I had trouble with, which is why I switched over and got my degree in Mechanical Engineering.
I have been thinking about a remark you made earlier about the gas being only 40% combustible. I really suck at chemical equations. Is it 40% because 20% of the intake air is 02 and when you combine the 02 with carbon it makes 2 C0s per 02?
I apologize for that I haven't bothered to review the chemistry involved. But the thought struck me last night to ask you why couldn't we introduce steam into some portion of the incandesent carbon to make water gas? Like the real old coal fired producers I read about from 1905. There is no way to get rid of the nitrogen? Make NH3, something, anything, to increase the fuel value at the intake manifold.
That brings me to engine options. Stock engines like the 8.2 liter Cadillac engine would be great on producer gas. You guys say that this fuel could be used in high compression engines without detonation so that would be good for a cheap Chevy 350 bumped up to 13:1. What really got me thinking crazy is dualfueling a 6.2liter diesel. Add a butterfly valve for a throttle. It could start and run at an idle on diesel, then when the producer is firing additional power could be drawn from the producer gas. The real magic thing would be to have a sucker fan start the producer and then start the diesel with both producer gas and diesel. In the states, I live in a place that is north of 50% of the Canadian population. A place where its often too cold to start diesels.
Finally, why are all the tuyere designs showing the tuyeres pointing straight into the oxidation chamber.
It occured to me that this is similar to my charcoal furnace. The tuyere for that goes in tangentially. It causes a violent swirl in the furnace. Wouldn't that vortex be helpful in adding mechanical motion to the fuel in a producer, to keep it from channeling?
Alright sorry if it seems like a ramble. Good days are like that.
Sep 9 2005
I have finally gotten a coherent idea of how this gasifier that I built, works. Sadly, now that I have it built, I now know how it should have been built.
The producer only works when the throat is so hot that the outside surface starts smoking the paint off.
I produced gas from a cold start three times so far. I think I have the technique down. Or at least I have had the same results three times in a row. I am starting to get a feel for how to tune this animal.
I put a six inch throat in the producer while the Toyota only has a inch and a half diameter intake.
Okay not to lead the witnesses,
I start the engine on gasoline, open the air valve, open the tuyeres, then light the fire in the producer.
I run the engine on gasoline at a high rpm. I watch the tuyeres and make sure they are glowing white hot.
I continue this until the paint on the propane tank begins to smolder. The hopper is hot to the touch.
Then I shut off the gasoline. After the carburetor bowl runs out of fuel the engine will change its pitch.
When the engine runs on producer gas it sometimes surges. It will run steadliy but eventually its rpms will slow and finally chug to a halt.
I am assuming that the throat in the producer is too big. The air flow through the throat isn't enough to sustain white heat in the charcoal. So I believe it becomes a viscious circle. The low airflow causes less gas to be produced which in turn causes the engine to slow.
I am pumped.
Could I put a restricter plate in the throat?
I should take the thing apart and put a smaller throat in it with sloped sides in the hopper.
Anyhow, I am on my way now.
Sep 1, 2005
The Toyota ran quite well today for about 20 minutes with vigorous shaking and tapping to agitate the fuel. This was the best run yet. I saw some things that needed adjustment like pulling the tuyeres all the way out to the edge of the wall. Am encouraged by the commander to continue my efforts.
Yeah, my goofy little gasifier on my junky little Toyota doesn't seem like much. Later when I get back to the bush, the knowledge I gleaned from my work here will serve my family well.
Thank you Doug, and thanks to the rest of you too.
Now the good news, the new gasifier built according to your pioneer design, although flawed, actually ran the Toyota for 20 minutes.
I have the carbuerator still intalled on the Toyota.
I start it on gas then shut off the fuel line. I have the filter barrel plumbed into the airhorn. The new gasifier is plumbed into the filter barrel.
Okay, I saw through the tuyeres, that the heat in the oxidation lobes was white hot. The Toyota chugged away when it finally stopped because the radiator ran dry.
Doug, I now understand that the gasifier has got to be totally air tight. Plugging one tuyere would change the air/fuel ratio enough that the engine rpm would fluctuate. I also need to have sloped sides on the hopper feeding the throat. My gasifier is really way too big for the Toyota. No tar in the airhorn. I shut the thing down when the radiator was low, and I also wanted the filter barrel to cool off a bit as well.
My next gasifier is going to be a lot harder to make because of the sloped sides and the great difficulty in sealing every thing.
The fuel I used was Charcoal that I made with the old barrel gasifier. That thing works great for making charcoal.
Anyhow, I was pretty excited when the darn buggy ran on the producer gas. It motivates me to move forward with my research. Learning the art, so to speak.
No turbos available here. I am in a prison. We don't have grid power, a 12vdc fan isn't availble or even practical because it has to be airtight. The reason I was going hand cranked is because I want every thing as simple as possible. The goal is to be able to start the gasifier with out any external power source besides muscle.
Tuyere With Gasifier Running Cold
Tuyere With Gasifier Running Hot
I simply bolted the hopper to a flange welded on to a propane tank. It leaks. It also is nearly impossible for the fuel to fall into the oxidation zone.
I do have the tee and by manipulating the valves I learned alot about the flammibilty of the gas I produced.
Going back to being airtight, I figured I could factor in the leaking flange by placing it just above the oxidation zone. The lesson is that the leaks aren't uniform nor are they easily compensated for with changes made to the diameter of the tuyeres.
The producer throat is too big because the Toyota can't pull a large enough volume of gas through the oxidation zone and throat to really heat the producer up enough. I'm sure the tar is getting through and just collecting on the saw dust in the filter barrel.
This is absolutely facinating though. I would say that rather than being frustrated with failure, I am inspired to further my efforts.
Okay, I want to ask about throat size. Yes, I read your previous post saying that the pioneer plans would be fine for a 2000cc engine. What I wonder is how to size the gasifier throat for the through put. Or rather is the cubic feet per minute dependent on the throat size or the tuyeres? I'm reaching here because I have a headache from the garbage they were burning last night I can't think straight. This make sense?
The Toyota is too sensational for this FOB, KBR and the fire dept. are always stopping by. What I would like to do is just build a bench top model that I can pull suction with a small aircompressor head. Hence the throat size question. I would guess that the intake line of the compressor would be a good place to start for throat size. One really has to get over the idea that this isn't a wood stove that one just idles down to make flammable smoke with.
Okay, am building a Pioneer style gasifier. I have questions...
Does the throat have to be movable? It appears that it is supposed to be adjustable relative to the plate sealing off the upper oxidation area from the lower output and ash pit.
Can I just weld the throat to the plate with it's top 50mm from the plate?
I toyed around with attaching a funnel to the top of the throat to facilitate fuel movement through the gasifier. Your design doesn't have a funnel except for where the fuel bin attaches to the throat section.
You don't do this because the wood chips piling up in the corner insulate the casing from oxidation right?
I built the grate by welding six pieces of 5/8" rod to the faces of a nut and then put the nut on all thread. by spinning the outside nut on the bottom end of the all thread. This gives me the adjustment required.
Its fun thinking this through and coming up with solutions.