Condenser for removing water vapor from wet wood

Do you think its possible to add a condenser to remove water vapor from wet wood?
I stumbled upon this video where they had problems when using wet wood and could not ignite the syngas.

Hello Veljko,
Most raw wood gasifier designs since the late mid-1940’s do have upper wood fuel moisture condensing hoppers. These were named from then Monerators. Specific informations on the origins of this are in the DOW Library section.

On this video shown system you can see internal detailing of this in Ben Peterson’s design books, “Woodgasifers Builders Bible” in three versions, 2012-to present. This particular build up is an unauthorized illegal sold kit-copy from that book. These folks buying and assembling this do not realize they have stumbled in to a legal action lawsuit.

You can also see moisture reducing monorating hoppers in Vesa Mikkonen’s system design book, “Wood Gas For Mobile Applications” published out from the early 2000’s to present. Mine is a 2010 copy.

And these feature can also been seen in Wayne Keith’s and Chris Saenz’s book published in 2013, available here on the DOW.

In all of these it becomes very apparent that size does indeed matter a lot.
The bigger the system then the more available internal heat and space capability for wet wood heating steaming out; and then cooling condensing out and externally removing that woods excessive moisture.
View through pictures of the W.K. systems that have been built shown here on the DOW site and all done properly by the WK books recommend design have large external visible additional around the fuel bin hopper condenser cooling tubes. And those systems having TWO (an upper and lower) condensate collecting trough-gutters.

Back to the Canadian folks in this video. The wetness of the wood they were using exceeded the capability of this systems monorating system. At some point they will have to realize that heat is being shed off of their single pass cooling tubes. Once they go forward with IC engine woodgas fueled running then that engine will have available heats from the engines cylinder, cylinder head, engine oil, and engine exhaust. ALL of these can be used to just-in-time heat and circulations removed wet woods moistures BEFORE putting that wood into the gasifiers hopper. Going on to electrical generating the electrical generator assembly will have shed off blowing heat that can be used too.
Few have ever pursued using these made, need to blow away heats for wood fuel improving benefits.
Dry and warm the wood before putting into the gasifier and then the gasifier itself can be simpler and have much better performances. Connecticut man D. Nichols; New Zealand man Doug Williams; and USA Ben Peterson all have show using, various use of systems heats to before the gasifier pre-condition fuel woods in the past 20 years.

In ALL system for from a cold starting up it is best to get it all up to good working temperature to use very dry pre-charcoal loading. Then initially adding only very dry wood.
Later once all is up to good stable working temperatures; then can be transitioned over to wetter woods.

Steve Unruh


I realize I can come accross as smart-ass, know-it-all.
No. I do read a lot. Making everything read be cross verified at least by two other independent sources.
Then I try-model further to my satisfaction. Proofs-verify:

The two rows of wood on the righthand side are at most ~20% by weight air reabsorbed moisture content from covered dry storage. This used to get a thick hot bed of charcoal established in the wood stove.
The round sticks criss-crossed (cribbed) stacked up too close and tight to the wood stoves side is Octobers winds-fall green wood. It did still have leaves. It is ~44% live saps moisture heavy never been sun dried. After 3-5 day be down to 20% and ready to burn clean and well.

The Dog? It is she the reason for this morning wood stove fire in first place. Just back in from a very wet&windy raining morning walk. Toweled off. Now she is dry warming her back.

The current fire state? A new piece of the dry fuel wood in front. Two sticks of the wet green wood in back on top of the established hot wood coal bed. They had kept getting bumped and rolling off of the drying stack. They first hissed like a pair of snakes from the heated round bodies driving oozing moistures out of the sticks porous ends.


We don’t mind, Steve. As long as there’s substance and the subjects are related to what this forum is about, I find this community extreemly tolerant.

The cultural norm up here in the Nordic countries is to be modest. There’s even an unwritten law, called Jante’s law : “Don’t think you’re special, don’t stand out and don’t brag”. Fancy cars and luxery is frowned upon and so are loud people who take up too much space.
From what I understand the Ameican cultural norm is more about being strong and independent. However, as we all are aware of, this forum doesn’t represent the avarage Americans or Europeans :smile:

Personally I’m somewhat introverted, but I find freeing to be able to brag a little (with a wink) about wood and stuff, without too many rolling eyes :smile:

Steve - you go ahead share your knowlidge and experience. We appreciate it.


I have a feeling things are going to start to fall apart for him. As all those design assumptions become reality on video by users experiencing those reality’s. Found another short video of an engine run where the video is cut off before the reactor crashes and engine stalls out.


Yup it does’nt matter how good of a gasifier you have bought or built if you Do Not Know The Other 75% of how to run it. And that is a fact.


What I am planning to do this spring is get some second hand 55 gallon drums with lids. Then taking a 1 1/2 inch hole saw and cutting holes in array at the top and bottom rims. Then painting them BLACK. Put the lid on clamp it down and just let them stand. Sun heats the drum and the holes then allow a draft inside. Lid protects the fuel from rain and hopefully the result will be engine grade dried fuel.

I dont know if it will work. But I suspect it will and you may need a lot of them. It depends on your usage. If not build more of them.


I plan on doing something basically like that with an old oil tank.

I might need a pivot so I can chuck the chunks in, then shut a lid. Tip it over to dispense the wood.

Use the 2" holes already in place and maybe a solar powered fan to blow air in.


So you basically say, forget the condenser dry the wood beforehand.
Perhaps I can just put them in the oven of the wood stove while cooking


I dont want to interup your chat with steve- but the cooling tubes on the hopper and the bed of the truck cooling rack is the condencer- i just HAS to be able to be cleaned. any more cooling tubes or condencing tubes,are too much extra weight for mobel driving. The wood need be around i think 25% max moisture. with a wood moisture meter. But if you chunk a big pile of wood up ahead of time, chunked wood dried in about a few weeks from what they say here on DOW.THE small chunks dry real fast compared to big slabs of fire wood.


What they are currently talking about with barrels and an old oil tank Veljko would be condenser drying the wood before hand. They propose using sun solar to heat.

Some of this can, and is done as I pointed out within the actual gasifier upper system. Actually best ideal for traveling vehicle systems. They have travel cooling condensing air flows. What Kevin was referring to. WayneK has a video of himself hopper re-fueling with water bucket dunked fuel wood chunks. An already worked heated-up system. Him then going back out traveling and working his system.
Tone added an external upper hopper fan blowing across on his slow moving; and sometimes stationary tractor, for measured benefits.

What I have proposed for years is more open air drying in multiple mesh screened one-hopper load baskets with forced blown supplementary heated air. These hung around and over open frame engine-generators
No attempt made to condense the vaporized moisture. Just blow the absorbed maximum humidity laden air away.
The IC engine and the generator heads do make heat that must be blown away for equipments thermal control life, and safety. See. A two-fold benefit if utilized. No extra heat source. No extra blowing fan.
Go feel this combined blowing out a single port in a small enclosed portable IC air-cooled engine inverter generator unit. That is collected, concentrated energies that can be used for input wood fuels conditioning.
One of Ben Petersons in-shop systems never released used a double walled open topped big steel bin. The between wall hot produced gasses flowing through, slowing, particle dropping being active elements “swept”. The gas heat rising up steel walls in direct contact drying and warming conditioning the input wood fuel stocks.
It evolved. The released and later sold commercial unit had the whole IC engine and generators under a tip up metal box covered. That box also bin open-topped for heat conditioning future wood fuel loads. Tipped up to dump in to a wheel barrow or raked into hopper filling buckets.
I have the very first, 1st generation-attempt one here. Real. In my shop. I shown it to a few.

Enclosing condensing out becomes complicated requiring much more complexity and management to remove the made back into a liquid moistures.
Sub-zero, cold dry conditions open air dries woods too.
Some have these conditions for week and weeks, even months in the winters.
But another gets complicated/expensive with management needed to do this artificially.

Size matters.
Working conditions matters.


I’ve showed this dryer before. Uses a rocket heater to feed hot air into the barrel and vent the moisture out the stack. I have dried half a barrel worth of wood to 15 to 20 per cent in two hours. When done the lid comes off and it tips into a wheelbarrow. All my wood is already dead and fairly dry before hand. I have never used it with any kind of green wood. No way to know how long that would take. I may build another one similar but horizontal, two barrels long and made to dump like a mortar mixer. May require a fan to pull the hot air through the pipe running through the center of the barrels.


You don’t even need to do that much work. I just take the angle grinder to the bottom and add a few slits. put the lid on. Optionally, you can remove the large bung and I put a pipe nipple in it for drafting and it prevents rainwater from getting in that collects on the lid. prop it up so it isn’t on the ground. I use old patio brick pieces. I didn’t even bother to paint the barrel. it gets hot enough in the sun. It will dry stuff with leaves on it, to bone dry and the leaves are green in like 2-3 days in the summer. It gets hot enough, that when I had punky wood in it, literally there was a puddle of water running out of it in the morning from condensation. And it is in a partially shaded spot.


I am going to have to try that type of drier now that i see you are here in mid michigan- i live just 3 miles outside if vassar,michigan. sounds like good summer time drier to me indeed. And maybe my wood heating shop and trailer heater chimney through a drum or barrel like tom menchinned with rocket heater effect. sounds like a barrel of chunks dry good in two three days, if not raw green,?


Give the credit to Sean if this works. He is where I got this idea from just so you know.

I have carbide hole saws. Those things rip through those barrels in seconds not minutes. LOL


I don’t have a chunker. I use it to dry out material mainly brush (basically anything from twig to firewood sized chunks that isn’t wanted) before turning it into char. I don’t see why it wouldn’t work for chunks, but it may take a little longer because there is more mass, but that might not be true because chunks have more surface area and end grain exposed.

Drying wood is a heat + airflow game. It collects heat, and there are some convection currents from the bottom to the top. It probably gets up to 150 degrees. Our solar beeswax melter used to get up to 170-190. It might not have quite enough airflow. But it does dry stuff.


If it doesn’t you can blame me too. :rofl:

Carbide bits are far more expensive to replace then angle grinder disks. :slight_smile:


You can get em on Amazon pretty cheap now. Yeah industrial supply used to be the only option.


I should probably do a look see. I actually could use some. My holesaws are bi-metal, they cut through sheet metal on a good day. I never realized how much better carbide was until I broke the torx bit off trying to get the brake rotor off and had to drill it out when i was replacing a bearing. I dulled the titanium bit I had, and it barely even cut into it… then I got the carbide bit and it went right through it like it was butter.

But I would still use a grinder. :slight_smile: