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?
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
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).
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 ?
I’m just going to give you my take on it. Over the years I’ve had many projects. I did a lot of research on homemade batteries and made quite a few homemade batteries. Also I did a lot of research on thermal acoustic engines and managed to design some rather large engines that have good performance for their type. And I always messed around with making wood gas cook stoves and just wood burning stoves. I began to realize that what makes a battery more efficient can be applied to a wood gas generator and even more so when I learned about thermal acoustic engines plays a big role in making a wood gasifier more efficient. I’m not saying that I’m correct but this is just my take. As with any battery in order to prove efficiency you need to increase surface area. And air electrode will give you a good example of what small passages through a construct will do. The amount of contact increases dramatically. So I figure that the typical downdraft gas fire is not that efficient because the combustion zone has a lot of mass and is compacted therefore not allowing air to flow through easily. Also the pyrolysis zone is backed up and it’s also too large for the combustion zone to process. I don’t even know if I’m using the correct terms here as far as the gasifier goes. I’m calling The mass of glowing carbon the combustion zone. It’s so large and hot that a lot of the residual heat rises and makes for a large mass of pyrolysis zone. If you base it on the air electrode it’s not about the mass it’s about how much glowing carbon surface area you have, and when it’s compacted air passing through tries to go around it because it’s just too thick and compacted. So with this design the glowing carbon is nice and fluffy and has micro passages all through it. Also it’s not very thick but very hot. Pyrolysis takes place just below this glowing carbon and the transition is rapid. The glowing carbon is full of micro passages which can be interpreted as the stack on a thermal acoustic engine. On a thermal acoustic engine you transition from cool air to hot air very rapidly and when this happens air velocity is increased. So the hot glowing carbon is the stack with all of its micro passages The cool air passing through is instantly superheated and converted to flammable gases. But it’s also accelerated just like the thermal acoustic engine. You’d be surprised how much more surface area there is coming in contact with the air because of those passages. Also excess heat is carried away and does not creep into the wood pellets very far causing a backlog of pyrolysis. It’s my opinion if you’re gas has a lot of moisture then the proportions are off. There should be no moisture passing through that wall of glowing carbon and if there is, proportions need to be adjusted.
Like I said this is just my take on the topic and I’m not saying that it’s correct. I’ve been retired for about 6 months now and I have always enjoyed trying to figure out how things work and tried to come up with new approaches. I have other interests also I have designed and built many firearms and currently I am patent pending on an original new gun design. And yes I cannot apply any gun designs to this wood gas generator. 
Your concept sounds interesting but hard to visualize. Will be interesting to see how it performs in the real world. Thats a way more complex act, with engine draw fluctuation, stroke pulsation, ash buildup…
About the thermoacoustic thing… it interests me for a while. I saw how much a single cyl engine pulsates and am thinking to use this effect to “supercharge” the output, like a resonant 2cyl exhaust.
Darren,
Many words chosen, many words used, many truths, but also many wrong assumptions.
Indeed the glowing charcoal is important, temperature related, but even more important is to understand Mas Flow correlation and Physical proportions / properties / behavior from each mass involved…
Understand what does make the carbon glow AND what does the carbon cool down, bringing that into a balance, then observe your result.
For example ( the easy one ) 1 Kg Carbon + 1 Kg Oxygen = 2 Kg Carbon monoxide in a perfect world…
However, there is not a perfect world… If you can not turn all thermal energy into a perfect balance then you can end up with a mixture containing a certain % of carbon dioxide.
Second example: 1 Kg of steam at 1,250 C mixed with 1 Kg of Carbon = 2 Kg mix Carbon Monoxide/Hydrogen mixture… ( leave it up to you guy’s to calculate the ratio 
)
Third example: i have an electric heated reactor, 1 Kg of Glowing Carbon inside at 1,290 C, The electric oven keeps the Glowing carbon at stable temperature.
Then i pass 1 Kg of Nitrogen thru the reactor, what do i get out at the other side ?
Answer : 1 Kg Hot nitrogen gas…
It all depends the physical behavior from each mass involved…
So many things we can test / do…
@KristijanL Imagine if you can preheat water to steam at 1300 C with the excess gas from your gasifier, then inject that into a smart position in your gasifier…
@Derwood anything can be tried, not everything can be done… but the laws of physics still do apply…
Finding ways to measure objectively and in a scientifically setting ( repeatability ) will give you a clearer view in how much efficiency can be reached , words however don’t do the trick.
We are all very anxious to learn from each other, to find the “holy Grail” , however and again, to be shown what has been done, achievements showcased in your builds…
What i can do in lab scaled versions, has little substance if it can not be used in real life situations.
It does however gives support to those who are looking into feasible improvements for their builds.
Looking forward to see the results from your work in progress.
Warm greetings from Thailand.