He was actually referring to all the energy lost in the char making process. You burn off tars which would get cracked in a woodgas system, then you have the loss in fines from the grinding process, etc. And for small engines the woodgas, doesn’t really scale down that well. For distance refueling, hauling around the extra weight and bulk of the wood may not make sense either.
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Yeah I love how everyone forgets chipping machines energy input and the waste that is produced, thrown away and then all the energy involved to dry it. Then we forget losses in the gasification process itself to combat the water.
Where are we getting this energy to run this equipment for free? We need to build systems that make that energy instead.
If you fully factor in all energy input for either in the big picture, (Gross feed stock pre any processing in to net energy out) They are really about the same, choose your poison.
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It could be a long debate 
I like char, but that is namely because I am getting rid of brush piles, and the ash and fines aren’t wasted. They just aren’t used for fuel.
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Yeah dont forget I was anti charcoal for a long time and would not even consider it. Nope wood gasification is better!! Your just burning all you r fuel away!! Then one day I tried it. As we know now Ive seen the light.
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You just have to design your lifestyle so that you have a use for all the processes. I don’t worry too much about heat loss from making charcoal right now, but when I get back to reworking my greenhouse there will be very little loss, at least for as much fuel as it takes to power a generator. I have a heater that has a coil inside and the burn chamber is surrounded by a water jacket. As I run the heater it will make charcoal and heat the water in a 600 gallon water tank inside the GH. The heated water in the tank moderates and maintains temps in the GH. The only loss will be in the flue which will run horizontal heating air until it exits the structure. The charcoal is being made from a continuous feed and not batch. When I grind the char to fuel size the fines become bio-char and are used to produce food. Minimal losses in the whole process.
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Yup that is why I like the fire ring appoch, build a fire sit around the fire with freinds and fellowshiping have a good time all the while adding more wood. Dana calls it a Bob Fire. By the time the evening end the fire ring is full of hot charcoal. Shovel into the water and the Fire is out.
Next day you have a big wheel barrel full of charcoal. Screen the charcoal while it is damp no dust store it in piles with tarp over it. Drys naturally. I like to use it when it is still a little damp 10% moisture content.
I would like to design the fire ring with a open chute that the hot charcoal could slide down into water and the steam would vent out the bottom hatch where the charcoal would be removed.
And then be piled up. I did this with my retort but it is not much fun sitting around it with freinds watching it burn the wood into charcoal. Lol.
Bob
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Bob you could always make a raised fire pit and use a big grate made out of rebar. Coals fall to the bottom into any water to snuff it out. Rake the grate every once in a while for the stubborn coals. My patio brazier basically acts like that but for ashes since the grate is finer sized.
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I was just reading this over and thinking about the efficiency and heating value of the gas.
" The energy content only drops 10%, the weight of the biomass can be 60-70% of the original mass, although the energy density can increase by up to 30%. "
And it overcomes some of the storage issues with moister.
But to build a kiln to produce it and the fine controls to produce consistent quality might be difficult.
Maybe a Continues feed roaster of some sort that feeds the raw wood at a preset rate through a system with a 550 F in a low oxygen environment for a certain amount of time before being dropped in a cooling hopper.
Down draft gasifier does this very well. All you need to do is optimize the grate so that is more passive so it drops the charcoal as it is produced. Use the gas produced for something it is very eficient. If you go to my Youtube and check out my kiln it easily can yield 50% by volume. But it is difficult to reclaim the energy. So I am going to build a simple down draft gasifier that will hopefully produce a mixture of charcoal and torrefied wood. I know now that my unit will devour raw wood so this fuel is no problem. Then we simply reclaim the gas produced clean it up in a gasometer and use in gas appliances and gas heat. I will mod a fire place insert so that it is vented.
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i agree matt, and each sourse has its pro and cons/ i deffinitly want too build a small engine charcoal burner, too see how charco works. IS the power loss the same with charcoal including water drip.?
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I was thinking a machine ( Kiln ) optomized for producing " bio-coal " might have a yield that is 90%. Not in yeild by weight or volume but in the preservation of energy.
Raw wood gasification is the gold standard because of its efficiency.
Charcoal production produces a refined superior fuel but at the cost of 50% of the biomass’s energy being turned to smoke.
Doug Williams planted a lot of ideas in my head in conversation off list before his passing.
To this day I still think about fluid bed classification, bio reactors that operate above atmospheric pressure and green coal as fuel for high performance mobile applications.
I don’t recall the wood in question we talked about once, but there was something that grew in Australia that he said burned like Anthracite coal.
Once seasoned it need water injection to keep the hearth from melting down.
It was the perfect fuel but not enough of it grew to be a real advantage.
The perfect fuel, the perfect gasfier…
Look at this I just was browsing the net…
A pellatized, torrified wood product with uniform properties of moister size density and energy content.
it just screams for a gasifier specifically designed to burn it.
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How do you make the perfect solid fuel and from what feed stock.
With all the talk in the media about Bio-ethanol from cellulose I think we have missed a big point.
We could easily process agricultural waste and other organic streams of stuff and run it through hell’s bio reactor to first ferment and get gasses off.
Green natural gas on an industrial level…
Next we could tap the residue as both feed stocks and binding agents in a pellatizer plant that uses the off gasses from heavy pyrolization of this material to fire the processes.
Everything would have to be done on an industrial scale to make the green coal.
But you could use it for so many thing.
We could burn in coal fired plants, use it as a home heating product, sell bags of it as motor fuel.
I wonder if it could even be part of a soil enrichment carbon capture process.
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High amounts of char slipping by the grate is good in a wood gasifer and is beneficial for making charcoal that can be used again if that is what you want. For mobile use this is not desirable because of the maintenance side of it and having to load the hopper every few miles.
But if you had the place and height on the vehicle like a big truck you could mak it work with a taller hopper and more storage place in the ash/char clean out area. Or this would work for the gasifer with a much smaller restriction opening running a Genset but making a smaller amount at a time. 6kv Genset engine vs. 7.2 L engine gas feed on a truck.
If you can be doing something like driving , generating electric, heating/cooking,heating/water it is even more beneficial then just letting all the btu’ s go up into the outside air. You do not want to be blamed for Global warming. Lol. Oh yes a open fire pit is under the heating and enjoying watching the fire dancing around. Very interesting and entertaining.
Bob
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Ya I know I built a Pioneer HA HA…
At no point did I say I wanted to build a gasifier for making char.
I proposed the idea of a machine for making Torrified wood or Bio-coal ( not to be confused with Charcoal these are not the same things ).
I love a nice night by the fire pit.
I do some of my best thinking whilst watching the flames.
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one of the issues is even after you get ‘green coal’ a coal plants operating thermal efficiency is only 40%. Our government is going after thermal coal rather then specialized uses like coking coal. If coal is a limited resource, then why waste it to literally boil water to run someones lights?
It really isn’t cost effective for some of the same reasons that cellulistic ethanol isn’t cost effective. You would have to haul massive amounts of material to a plant to be processed. Then you have to store it at the plant and hope none of the material spontaneously combusts while waiting to be processed, which happens if the material is too wet and the bacteria can grow. Then there just isn’t enough. You are also removing carbon and nutrients for the soil which means you have to add those back somehow.
to top it off, the efficiency of a plant to convert light to energy is actually fairly low like 3-4%. Solar panels are around 20% efficient, with the 3-4 junction non-concentrator cells maxing at 39%. So if all you want is energy, then it is more land use efficient to use solar by 5x. plus they can convert all year. It does not mean you can’t use plants or even coal for certain applications, but those are specialized applications and not 90% of the US coal use which boils water. (I assume the 90% number is fairly consistent globally)
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Okay I was not sure where to put this because it deals with a few topics we have been discussing.
Last night I did the fire pit charcoal making after the evening was done I pored water on the pit of charcoal and went to bed. This morning I got with a wild I idea. Oh yes it happens to me too.
Why not just shovel the top layer of the charcoal and put it into 5 gallon buckets no running through my screen barrel trommel.
Because of my gold prospecting and panning skills I let the water do the separation of light materials from the heavier materials. This same action applies with charcoal and the fine ash materials. I took only a flat head shovel and lightly scrap of the top layer of charcoal and placed it in the wheel barrel.
Only one brand was left when I put the water to the fire.
Into the 5 gallons buckets.
All that was left was fine charcoal and ash that I can still screen and get more charcoal, I’ll do that later. I have a almost garbage can full of this stuff.
So now what you might be saying . I start up the Dakota Truck. And put that moist charcoal in the hopper with my cherry wood chunks.
Warmed up the gasifer real good and went for a drive.
Only used one bucket of this charcoal.
I found out what Kristijan has been saying all along. 80 mph. Would have been no problem. My gas was running extra rich. Normally with my auto mixer it runs at the lean side and I will have open my by pass gas valve to run a more rich gas mixer. If I bearly open the by pass gas valve it would go to the rich side of the gage. And boy would the truck pick up speed on the flat road.
I am posivtive now like Matt, Kristijan has been saying about the hydrogen increases in the fuel mix.
One of the beauties of The WK Gasifier is with wet charcoal you can run it.
Now how fast did I burn through a half hopper load of charcoal and wood mix about 2 wood to 1 charcoal ratio? Pretty fast 14 miles and I had to shut my gasifer down. Hopper spiked up fast to 400 plus °f in seconds , I thought it was bridging, more of a hole to the nozzles on inspection.
I am thinking these charcoal chunks are insulating and keeping the H2O traped into the thousands and thousands of of voids inside the charcoal. With wood it cooks out differently. Anyway it was a noticeable difference in performance of the truck.
Next experiment maybe straight moist charcoal in Hopper? We will see. One thing about charcoal that is moist it is still lighter then wood chunks.
Oh yes I did drain my condensation tanks no water out the back tank and 1/4 of a cup out of the Tar/ water tank. Very interesting. I am going to try the same experiment on the Double Flute Gasifier. I will start it up with dry charcoal then add the moist charcoal in hopper.
Moisture content was 44% on the pieces of charcoal that I checked.
This is a lot higher then what Kristijan recommend. Another beauty of the WK gasifer system it can handle the water.
Bob
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It is astounding how little condensation you guys pickup, my last 20-30 bags of softwood fur and pine at 10-12%mc I am still catching 4-5 gallons a day between hopper, rear tank, hay filter and slingshots. I thought with the moist charcoal it would have been even more?
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No because the charcoal is the catalyst for the water shift conversion and is local when oxidized.
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My cherry wood was 5% mc and it was stored outside in a feed bag covered with plastic tap, under a shelter. We have very dry winters here. Lots of pow pow snow the ski and ride on at Mission Ridge Ski Resort.
Bob
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Bingo!!!
If you simply heat pure carbon in the presence of water the carbon will strip off the Oxygen to for CO and free the hydrogen.
Under isolated conditions you need double the heat to do that.
Wood has water locked in it we can not see.
Bone dry wood still has water locked up in the starches and cellulose, lignin ect.
Heating the wood to pyrolize these things and liberate them from the wood is a load on the gasifier.
Breaking down the wood is an Endothermic reaction in itself.
The next water gas reaction is also Endothermic.
By skipping the middle step we can make richer gas because when have more energy in the system to spare in the reduction zone for additional reactions.
This is one of the reasons I sound like a broken record always rambling on about higher temperatures, more insulation, heat ex changers and of course pressure.
Bob:
I wash my charcoal too.
Mostly to reduce dust and rid it of impurities.
The I store it in paper bags in my shop attic where the heat drives off moister…
Activated Carbon LOVES water.
Going to add something we never talk about.
CO reversion…
At higher temperatures CO is not stable molicule.
It wants to become CO2 that is inert
Some of the ultra fine carbon dust that gets past our filtration systems is from CO that reverted to CO2 because it found the right conditions to decompose and recombine.
I can’t prove this, but I believe one of the reasons hot high load gas is leaner is because of this, post reaction the whole system is hot and this is why we want to rapidly cool the gas.
Temperature is important, too hot is bad too cold is bad and staying too hot after exiting the gasifier gives the CO more time to revert.
I think but can not prove the more efficient water gas shift is making cleaner gas at a cooler temperature than wood alone and in part this will keep the whole post reaction section a little cooler than it would be to make clean tar free gas on wood alone.
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