Hello everyone, I’ve been playing around with with gasification for years but have always tried to come up with a simpler process to produce clean burning fuel. Throughout my years of messing around with this hobby I have come to the conclusion that only a small hot Mass is needed to create a continuous steady flow of clean burning gas. I guess you have to really understand what’s going on with the process. Some people think that you’re getting gas from the wood or from the charcoal but that’s not the case. You’re burning wood to create charcoal, a glowing mass of carbon. All incoming air if directed through this mass of glowing carbon is converted to hydrogen and carbon monoxide. Carbon dioxide in the air that you breathe, when pass through going hot carbon is converted to carbon monoxide because the oxygen atom stripped away because the glowing carbon is very hungry. Also moisture in the air which is water, is converted to hydrogen because the glowing mass of carbon strips away the oxygen molecule. If your gasifier is working properly there should be no moisture in the system. All moisture should be converted to hydrogen. So it’s all about surface area not mass, very hot surface area to be exact but not so thick that air has trouble passing through. I have been experimenting with a much simpler design that seems to be working really well. All tars are cracked and burnt into ash The output is very clean other than ash. I have not started the ash filtration system yet but that would be the only hurdle. Tar is not a problem. I have been able to produce a constant uninterrupted very blue flame for over an hour on just 20 cubic inches of wood pellets. After running the system for several hours there are no traces of moisture or tar build up anywhere. It doesn’t even smell like burnt wood.
I’m testing out a positive pressure system that produces gas at a constant rate. I think the trick is to produce more gas than what the engine needs and have a pressure release torch to burn up excess. This way you do not have to depend on the engine to create the amount of necessary airflow and since the reduction zone is so small there is very little excess heat. The reduction zone is about two and a half inch diameter and only about 1/2 to 3/4 in thick and the more air you push through it the better quality of the gas is.
Welcome Darren! Are you able to share a more complete description of your design?
Yes I can share. I’ll have to make some video. The only video I have right now is at night while it’s burning.
Hi Darren , thanks for the Video cant wait to see a little more when its running during the day time ,always exciting and interesting to see how other’s make and improve on running designs ., where about’s are you from ?
Dave
I live in West Virginia just south of Huntington
Just based on past experience with gasifiers I feel that the current prototype produces enough gas to run a 5500 watt generator. The gas is very clean as you can see in the video. I can produce that much gas for 1 hour without any interruptions using 1.6 lb of wood pellets
Yes what you wrote is true. However the main sorce of CO2 and water is the pyrolising wood just above the burn zone.
The burner idea thugh is a bit overkill… generators generaly suffer wery litle problems with fluctuating gas draw. Problem are vehicles. You need 100% power at green light but at the next red thats only a few % at idle. Burning the gas is not a safe or economical option and neither is venting our unburnt gas (CO).
In order to keep your gas clean without any tars you must keep the burn very hot. If your engine does not draw enough air then the charcoal will not get hot enough to burn up the tar. As far as economics go you could vent any excess gas and burn it with a generator. Like I said I’m only burning 1.6 lb of pellets per hour and that’s at full production with the blower. There is a temperature range where it does make clean gas and tuning it for a engine to keep it sustained would not be that hard.
A 40 lb bag of pellets would be good for 27 hours
My goal is to run a generator at this point. Running it with very clean fuel so that it is not damaging the engine. Venting a little bit of excess gas and burning it should not be a problem while running a generator.
Yes you are spot on. Most of the CO2 comes from just above the burn zone due to pyrolysis.
I dont want to be seen as a smartass but once you hook up the generator that fuel consumption will be closer to 1.6lb without the comma… if you want any serious power out of it. In my experiances a rough wood consumption estimate is obtained by taking the weight of petrol the engine consumes x2 to get the weight of wood. So for a 5500w gen at full power thats around 12 pounds.
Im not doubting the efficiancy of your sistem, its just math. A pound of wood produces a certain amount of gas and an engine consumes a certain amount of l/s.
You may be correct. It’s going to be fun to find out 
Thats for sure! It always is with woodgas!
I failed to mention that with greater gas demand that you have now there is no worry of ever geting the gasifier runing to cool making tar so l wuldnt worry to much
Hi Darren, welcome to DOW…
Many words in your post, lots of conclusions you made…
Give it some time, do a lot of different tests, you might be surprised needing to adjust some opinion having now.
There are many tricks, so many tips, so many tests to perform…
learning doesn’t end…
Your system now, as in the video, (can’t wait to see some more detail in daylight ) run’s on a slow flow (relative) just within a sweet zone, not overpulling the gasflow…
gasification (wood) is a combination from exotherm and endotherm reactions, well balanced…
Depending each individual system / parameters, the balance will need different adjustments…
Using the wise words from SU, woodgasification is pulling smoke thru a pile of glowing charcoal…
So true…
Being a “gasifier” myself ( … a person that gasify’s any type of liquids/ solids into a gaseous form ) for over 50 years now… I am still learning / measuring / amazed every day…
Mistakes and misconceptions are my daily bread …
This might be not the best way to have a balanced / efficient gasifier, as gasification into clean gas prefers a reduction of air/oxygen/nitrogen mixture. Suction vacuum, does that best. Positive pressure adds , but does not benefits, oxygen/nitrogen flow and same effect as overpulling.
Once some oxygen molecules pass the reduction zone, the hydrogen will burn after the reduction zone, creating moist in your gas ( even some carbon burnt , turning into Co2 and heat… )
So many things can be observed, experience to be gathered, by simply doing it…
Many laws of Physics do apply, you can’t change those…
This you might study a bit more, old book are available in the DOW library…
Running a 5500 watts will require quite a bit more than 20 cubic inch of woodpellets/hr
More likely 3 Lbs per 1000/watts/hr
The burner idea: instead of flaring of , why not flame that into your gasifier air intake with a high as possible flame temperature possible, giving much more efficiency and performance ? just my tested 2 cents.
Anyway, welcome to DOW and looking forward to your builds.
Koen from Thailand…
“The burner idea: instead of flaring of , why not flame that into your gasifier air intake with a high as possible flame temperature possible, giving much more efficiency and performance ? just my tested 2 cents.”
Some food for thod. Need to do some calculations (nitrogen reentry)
Hello Darren and welcome to the DOW.
Several years back I was up in your neck of the woods and went across the new river gorge bridge . While on the bridge looking down never before felt so small 
We spent a little time in the park .
Yeah. That was Grandview Park. And it does have a very grand view of the gorge
The burn chamber has positive pressure with a restricted output. This is just a test version to determine the burn chamber tube diameter. It is a updraft system that burns from the top down. That’s my simple explanation although there are other things I’m doing inside the chamber. It seems to be making really clean gas. I won’t be able to actually test it on a small engine until I get the filtration and cooling complete. It won’t be perfect but it will give me valuable information.
These did let me smile and same time are having me confused…
Any schematic available ? Care to elaborate ? How ?