Neither am l. And its a good thing. In my experiances highly educated people dont have time to do much usefull work or even discussion 
Bingo! Air is the key. The main reason for soot is incomplete combustion of tars in a gasifier. Just as it is in a stove! Creosote is a completely different thing thugh…
Now that comment caught my attention.
What is creosote?
Is it cooked condensate, tar?
I sometimes get black ice sickles hanging from the hopper lid.
Exactly. In a chimney, imagine a stove that does not operate optimaly. Wood simmers inside and the thick smoke full of tar drags its self trugh the cold chimney. Tar condenses out. Then, the stove starts burning hotter. The tar dryes, puffs up and forms the creosote we know. Its composed of baked tar so a huge fire hazard!
In a gasifier, its the same. Full hopper, the tary gases condense on the lid and drip down. Then, when the wood level lowers, the heat bakes the tar in to that kinda black popcorn we all know
This problem is what caused me much thinking when l designed my stove. I do want to be able to get a full blast when cooking, but l also want to smother the heat down in an instant, not to let too much heat in the room. And have a reserve of smoldering wood to catch on fire as soon as possible when l need to cook again, with litle kids that culd be an hour after lunch its this situations that produce lots of tar and creosote and can ruin a brick chimney, or make it dangerous to fire. So, this is the second reason why l have a second steel flue in the brick chimney. The tarry gases can escape trugh there. Once in a while l start a real hot fire and the heat will sweep the flue for me, throwing peaces of creosote 3 feet high over the flue!
https://www.foa.org/docrep/x5328e/x5328e00.htm
I am trying to get FOA Forestry Paper 41 “Simple Technologies for Charcoal Making” to load.
Search this one up. Read specifically Chapter 12 “Byproducts” for great explanations of tars, creosotes and Stockholm tars.
In there you will read that up 17% yield of Methane CH4 is possible.
And their best case final weight of unreducible tar matches what Wayne Keith is now final cooking down producing. 0.03% of the wood weight put into the system as I recall.
Bluntly a wood stove, wood furnace can and should be operated to burn up virtually all tars and soot’s, and never creosote up the chimney stack.
Back to the dis-belief that I and others routinely do this. And do this for years and years.
That I must be a lier. A boaster. A hollow man.
A wood gasifier I have had to come to accept is a gooey stinking Tar-Baby up in the upper hopper.
Different wood-hog beasts, for different results.
S.U.
Hi Mr. Steve, thanks for the link, lots of interesting reading. If I summarize the part that interests me at the moment, after drying, the wood is heated to 270 ° C, thermal decomposition begins here and energy is released without adding air and gas is formed.
"Wood gas is usable only as a fuel and usually consists of 17% methane; 2% hydrogen; 23% carbon monoxide; 38% carbon dioxide; 2% oxygen and 18% nitrogen. The calorific value of the gas is about 10.8 MJulov per m³ (290 BTU / cu.ft.), Which is about one third of the value of natural gas "
If this is true, methane is formed during pyrolysis in the upper part of the gasifier, and the question now is how to proceed so as not to lose it in the reduction, to break down only water vapor, CO2 and tar there. It must not come into contact with oxygen at high temperatures, which would mean burning,. ,
Hello Tone,
This is the only publication that I’ve read giving these ratios of CH4 versus H2.
I long considered it to be a miss-print exchange.
Then Joni mentioned he was developing/operating and getting much higher than typical yields of H2?, CH4? He has accessed much unpublished to us Soviets’ gasification research. I read much. Sometimes I will misremember.
But I’ve seen many 21st century woodgas producers getting Lab tested 4-6% CH4.
I do not know where in-system CH4 is formed. Above the air nozzles? Below the air nozzles?
Operating environment conditions?
S.U.
My thinking is methane gets produced in big low turbolence gasifiers more. Pyrolisis gas passes trugh the bed of glowing charcoal where it gets cracked. This IS true cracking, a catalytic reaction. Ash is on the surface of the charcoal probably plays a key role as a catalyst. But, since the air jets dont penetrate in the center of the glowzone, the methane can not oxidise in to CO and H2, yet is still sufficiantly clean and well cracked due to longer low-temp contact time with the big bed of glowing carbon.
Side product of the cracking reaction is soot. This may be one reason why a WK makes a lot of soot, compared to say a lmbert. At least thats what l am observing… But then again, JOs Volvo disprooves this theory…
Anyways, methane is a tricky thing to go after… Yes, its caloric, and not hard to make in a gasifier. But, there is a slim line between where the tar is all converted to methane and where it is not… We all know what follows in that case
So the sizing of the striction opening is the key, so at idle no tar can get by, but at highway speeds there is still enough restriction opening to make useable power for your vehicle. With the benefit of making CH4.
Bob
If we want any noticable amount of methane we can preety much forget about idle in such a gasifier…
Here I filmed my boiler, which works on wood chips or logs, it was never necessary to remove the creosote coating in the firebox, as it deviates from the wall, and in the chimney it is practically absent, only fine ash. Based on the observation, it was necessary to balance the ratio between the gasification air and the combustion air and to keep it stable at different operating powers.
I’m surprised you get any creosote in your fire box Tone. The U shaped duct run on my stove is like what you showed when you removed the plate. Just fine white ash. Any creosote I get is in my flue and that’s only because I have to do a dead cold start every morning so there is some unburned smoke going up the flue. I normally just brush it out and vacuum out the cleanouts once during the winter. My flue is 30 ft long and the temp where is comes out of the top of the stove in never more than 300F so at those temps anything in the smoke will tend to condense on the flue walls.
I agree 100% with your statement Kristijan.
Only a narrow range of conditions will produce a maximum of CH4.
Vehicle powering forces too wide of usage. And will drive the system outside of this narrow range of best CH4 conditions.
Even on small scale electrical generation the user demands will force out of best CH4 range.
A true story here:
The wife turning on two of four electric cooking stove burners to make family breakfast.
Meanwhile; oldest daughter after taking a long-hot electric water heated shower; then goes into electric high wattage hair drying blowing. Meanwhile; cold blooded Granny in her room cranks up her wall plug-in red-glow eclectic heater to warm her feet and legs.
And ALL doing this at the same time!
Ha! This is a true story from one of the big single cylinder Cut-Grid diesel guys. First he wondered why his news channel TV was voltage browning out. Then why his diesel engine was RPM loaded down: drooping voltage; not making 60 cycles; and blowing black exhaust smoke!
So he was the one to take cooking, water heating OFF electricity and onto propane.
And Granny’s electrical heat usage?? He did not say. I was afraid to ask.
Tom and Tone you remind me that heats harvesting with water off of wood combustion is a whole, another game to learn to play.
My rules of Ford Motor Company-like FAST rpm (heats-made)/high flows; from cold, system heating up cannot be depended on.
AS I was writing this I had from cold early morning; set-up and fired up my woodstove. First 2-3 pounds in 9 piece’s of fine split wood. Three layers crisscrossed. On top of a bed of crumpled news print. (bottom lite)Top covered with pieces of consumer pasteboard packaging boxes. (first hat-holding hot smoke - then self liting and smoke burning; T-LUD’ing) With ALL four stove airs wide open. Let it full roar burn down to newly made hot charcoal. 2-4 minutes. Then 5 pounds in three sticks wood on top and cut back to just 50% primary and self-drawing secondary air. 10 minutes once those fully surface flared burnt off to char; then cut back to just 20% primary air and char-glow HOT cruising hour after hour.
Your water masses as DanN.H. recently said can never be let go cold, cold or on downdraft/cross-draft systems; kills your draft flow.
Or: requires and hours re-heating time to stable conditions.
Tone nice up draft yours’s shows with the fly ash flecks in your video.
Regards
Steve Unruh
If I were building my system again I would drop two of the full size oxygen tanks about a foot down into my fire box and use the flames to heat the tanks. I’d probably still thermosyphon them with the pipe grids as well.
I think it would turn out to be an interesting option for travel and household if it was converted for spark ignition, since the fuel pumps of such engines have a lot of electronics, and the Audi ignition distributor, from a five-cylinder gasoline engine, would be very appropriate.
Hi Joni , I respect you and your work in the gasification world , you have a very well elaborated design of the gasifier , in your papers you talk about the direct C to CO transfer , how do you explain this ? What are the conditions? What do you think about the formation of methane in a gasifier? I have quoted somewhere in the literature above that charcoal is formed when cooking, as much as 17%, at temperatures below 450°C, what do you think?
Hi Tone
I don’t know a thing or two about charcoal and its preparation, since I didn’t make or use it at all. Regarding the direct transfer of fuel carbon to CO, everything is very complicated there, but in simple words this can be explained by the fact that at high rates of air supply and the general passage of gas through the active layer, the carbon oxidation reactions do not proceed completely, there is simply not enough time for this and "unburned CO "is simply taken out of the reaction zone … It is interesting that the gas from such a gas generator has a higher content of combustible components, in contrast to the classical ones with the reduction of CO2
Hvala Joni za vašo pomoč in vaš čas.
I was given a chemist book from l belive 1943 from my great uncle, it also breafly explains this. In it it says carbon burns with air to form CO2, but only under around 1000c. After that temperature, the reaction skips a step and instead produces CO. The molecules have so much kinetic energy that oxigen only has time to bond to carbon once.
Since you also do blacksmithing, you saw that for sure. When you get the coals hot enaugh, even with a lot of oxigen you see flames of CO gas burning, shooting out trugh the hot coals.
I also can confirm this in a gasifier. On my Mercedes l had a tiny gasifier that ran on wery water poor fuel mix, read charcoal/wood mix with a big excess of carbon. The volume of active carbon was maybee 2l, yet the car had no problem driving at 130kmh. Reason is it ran super hot! Unlike the clasical wood gasifier, where we have a oxidation and a reduction zone, this only had one zone, a reduction zone. As air got in contact with superheated carbon in imidiatly produced gas.
Do l advise doing that? No. To run a gasifier that hot means ash melts in to glass. A absolute pain to clean out!
