Currently here in the USofA nearly 20% of our continental large country is suffering grid-down effects of seasonal hurricane Helene.
So the IDEAL for me has always been a home-power electricity woodgas system able to step in using storms and disasters brought to the ground woods as fuels. These will be a mix of sap green woods; once building materials dry woods now very, very soaked wet.
The same as war condition like now in the Ukraine.
Others: their goal is to annually supplement for the predictable cold winter low PV solar times.
And some developing for complete No-Outside-Grid annual self-made electrical power.
Woodgasification (good engine grade fuel gas making) can be, and has been discribed in many ways.
Here is mine.
Think of the combustion triad of: Time (in residence exposures); versus Temperatures (the actual energy conversion); versus Turbulences (the mixing).
One factor over-emphasized then the other two must be reduced.
One factor minimized; or ignored; then the other two must be dramatically increased to balance out the triad needs.
Of course other factors drive the system developed needs and gasification style you will need to develop.
Your annual prevailing climate!!!
The trees species that like your climate and areas soils.
Your own personal energy you can daily/weekly/annually put into operating and fueling a DIY home energy system.
A couple of important tips have been pointed out already. Minimizing the hopper volume capacity will change your ability to handle wet and tars/soots making conifer woods.
Even using very pre-dried woods you will system choke with large many hours run hoppers.
Now to get that very dried and warmed just-in-time fuel wood because you are stationary you need to use every possible system rejected waste heat in engine cooling and air flow; engine exhaust; and even generator head heat to actively dry and heat the fuel wood bits just-before batch loading into the 2-4 hour run hopper.
Most . . even most here refuse to think in these terms. Boxing themselves into only one, maybe two step perfecting idealizing. Instead of full systems energyās integrating.
Vehicle developing then the relatively light weight and compaction needs drive the developing.
Stationary is different.
To me charcoaling is still just pre-use fuel making and storing. No diffnert then pre-stocking propane, gasoline, diesel, sun dried wood in a weather sheltering shed . . .
you bought time until used up exhausted.
And you do need true dense hardwoods to make storable, handleable, wood fuel charcoal.
A nearly worthless pursuit in conifer woods lands. Conifer stem wood charcoals are fragile and will crumble when handled into soots powder. The tree having soils taken up far less minerals and silica. Ha! True hards woods then the gasification trial is ashes and clinkers.
Iām with you on that one. Thatās my thinking too, but a wood gasifier needs certain dimentions to be able to keep enough heat in - a small surface area to vomume ratio - why the polar bears are chubby with small ears
As Steve pointed out, there are several other ways to help keep the heat up - really dry fuel for example. Superheating uneccessary steam in your charbed is extreemly energy consuming. So, a wood gasfier for a small 0.6l engine is not impossible, but harder.
Also, it depends what you intend to use your engine for. If youāre running your engine close to full power for a generator to charge batteries for example. The gasifier could then be built similar to what you may expect for a 2 liter woodgas vehicle, which has to run close to idle now and then.
The reason is tar and moisture. No matter how dry your fuel is the chunks will sweat - get wet, sticky and gluey above nozzle level. Below nozzle level itās hot and dry and the char will flow like peanuts.
Charcoal is actually easier. You dont have to chunk it up and you are not limitted to what will fit in a chunker or chipper. If you have a good retort you dont burn very much fuel. You just need enough to get the retort into gasifcation mode and it will self sustain its own process heat. Anything you lose is then put back via water injection. More water = less charcoal you need to feed the unit.
I can have a weeks worth of fuel made in one day with very little work to making charcoal. Wood fuel I cant even make enough for one day in the dead of summer. Cold months forget it.
Ive done both and I use to think just like this. I spent 8 years banging my head against the wall and spent nearly a million dollars on development without a success. Then finally I tried making charcoal and started developing charcoal systems. Within one month I dropped wood fuel and all that development. That was a hard pill to swallow that was 8 years of my life that I lived and breathed this every single day of that 8 years and just like that I threw it away. Why? Becuase it dont work. It might be ok for those that can deal with tar and fix engines. But for a consumer product it can not produce one drop of tar ever. If it does you dont have a consumer product and should not be selling it to the consumer.
Wood fuel on small engines will prove to be more problems than it is worth. When you actually try to make charcoal you will see its not so hard or dificult and then when you see how stable and reliable charcoal gasifiers and self sustain you will drop that wood gasifier aliong with all the problems that go with it. Murphyās Law " If it can happen; It will " You are going to make tar at some point if you havent you aint ran it enough yet.
I wish I would have started there from the beginning.
Not to mention CHP is by far easier with charocal. You can use that process for heat and hot water and then fuel product for generator fuel power generation. If you want to be inovative persue charcioal.
Now this here is getting into the convincing territory Soo, what are the key differences between a wood and charcoal gasifier. I assume you cannot just throw charcoal into an imbert and call it a charcoal gasifierā¦ I mean what makes it run cleaner, is it just the fuel quality and moisture level? Or are there any major differences in how the reactors are designed. As you can tell i know nothing about charcoal.
So the burning itself happens at around the air intake, and by the time material reaches the restriction it is not wood anymore, but just a burnt up carbon n ash mixture? And this is why it doesnt clog anymore once it reaches the restriction. Am I understanding this correctly
They are completely different technologies. With charcoal all the tar is expelled in the charcoaling process so its basically elminated. The reactor is just a big can and with pipe sticking inside. < yeah I know its so stupid simple your brain is trying to make it way more complicated than it is; while you are reading this right? No its just a big can with a pipe sticking inside, no restrictions, no complex jets, no complex grate system, no complex hopper management, no crazy filtering and gas cooling, no tar, no fidling around restarting your generator every five minutes. Just an open flow gasifier that cracks water into H2 and CO that will run sulf sustaining and reliable without valve and engine destroying tar. Once tar gets inside your engine; it never comes back out.
A charcoal gasifier does not just run on charcoal. They are also " water gas generators " Water is also a fuel input just like the charcoal. You creat a simple water drip tube to feed this pipe with a flow control. Water feeds in > it evaporates ( evaporation process cools nozzle) > resulting steam is then reacted with the carbon ( charcoal ) Carbon reacts with Oxygen and it tears it away from the hydrogen to form CO. The water molecule is now cracked and the H2 is left free.
That does sound simple! Is the pipe for gad out or air in? I presume its one or another. So the water is good and helps split the carbon and frees the H2, thats awesome.
How dry does the charcoal need to be in order for this to work good. Another issue with wood Iām having is that it is hard to dry and takes a while. Iāve heard that its even harder to dry coal.
What ballpark size is the can about? Lets say for 5-20 hp engines?
The nozzle is your air jet. You just need one jet and it needs to be cooled. That is the primary reason for the water injection. The water splitting is a byproduct.
Once the wood is reduced to charcoal in your retort and has cooled it is ready to run. Everything is driven out there is no water in the charcoal after the retort so there is no need to dry it. We are litterally injecting clean water into the gasifier to replace some of what has been driven out via retort but without the destructive tarry molecule chains.
Look up the simple fire here on the forum. That is where everyone should start out with charcoal. You will learn everything you need to know starting there and can build something that works fast and on the cheap. Then follow along with some of us that are developing further. But first lets start with the basics and start with the SimpleFire.
Nice, seems like it lives up to itās name!
It looks like one could get it together in a couple afternoons. I will finish my big ass attempt at a wood gasifier first though, as Iām only days away from completion.
Weāll see what it does, and probably confirm the issues stated with the design before trying the simple fire in a couple weeks time. Iām a subborn idiot, so Iāll probably be trying to change everything i did wrong with this design atleast twice before accepting defeat. So it miight just take a few weeks before i get to it.
Is it possible to make the fuel hopper larger on the SimpleFire? I know I should start with the proof of concept, but still feel like half an hour is a bit too short, especially since you have to shut off the engine to refuel. Does increasing the fuel supply have the same negative impacts as it does on the wood side of things?
LOL you are in good company. Like I was saying I spent a long time avoiding charcoal 8 years. Im not one that does this on the weekends or delves into a build once a month. I do this every single day of my life 24/7 365 days a year. Its how I put food on the table.
Note to all members, when new members want to run small engines. We need to put the breaks on wood fuel builds. Get these guys starting out with the SimpleFire first. Get them learning and grasping the technologies on this first. This way they are not wasting thier time and money and like all of us trying to re invent these things that they have never built. Trying to solve problems they forsee but are not really there for example.
Once you have built a charcoal gasifier or simplefire you will then get some experience and will learn the processes as you go. This is the foundation you must learn first. Then you build from this foundation and can revisit building a wood fueled system later if you desire. Chances are you are going to find charcoal is not as hard as you thought and is actually more viable for daily fuel production.
Thatās right. I would say wood is turned fully into charcoal already - at or slightly below - nozzle level. The glowing charbed below then converts steam and CO2 into burnable gasses. It also acts as a safety net to burn any trace amounts of tary vapour. Thatās why the restriction is needed - to keep the velocity and heat up.
Wether you choose wood or char for your fuel itās all about trail and error. Even a thousand words couldnāt teach a person how ride a bicycle. Itās the same with gasification. But, as soon as you get the hang of it, itās relatively easy.
During WW2 over a million vehicles were converted to woodgas in Europe. Almost 10% of them in Sweden. Most people used charcoal to start with, but things evolved more and more towards wood gasifiers. Raw wood was considered more available, cleaner and easier to handle.
Still, people were happy when the war was over and liquid fuel was available again. Only a few kept driving on wood. A wild guess is it was our type of people - those who maybe built there own gasifiers and had a bit more understanding of the process and therefore experienced a smoother ride - compared to avarage people with store bought gasifiers.
Makes sense. If Iām lucky i might just get this thing working good enough for my current needs. Like I said earlier, not looking for everyday operation (yet ), just something that I can tinker around with and get a few hours of generator runtime.
Also I am an mechanical engineer and know my way around engines. So I will gladly clean tar from the valvetrain and combustion chamber once or twice a month in compensation for my sloppy gasifier build. I decided today that I will drop a 60mm restriction into the the thing right from the start, so this should hopefully reduce the tar amount by a bit.
Weāll see how the first testflare goes in a couple days. I will keep you updated.
Gladly? I doubt it
You shouldnāt need to. What happens if youāve made tary gas is the intake valves can stick to their seats when the engine cools down. First sign is the throttle will not move as freely as it should. If ever in doubt, try turn the engine some by hand before you start to crank up. If itās stuck - heat is the key. On a car, plugging in the block heater is usually enough to loosen it up.
Lets just hope it doesnāt happen. Iāve been driving about 10 000 km a year on wood for the past eight years. Iāve been cleaning the throttlebodies quite often but never experienced a stuck valve.
Just one more thing - I guess you already know, but - remember to prefill with plenty of white ash around the restriction and the rest of the firetube with charcoal, sized between peas and pop-corn, all the way well above the nozzles. Never ever start a brand new gasifier on wood only.
Daniel,
I donāt think Iāve seen anyone mention FEMA in this thread, but the last illustration you posted resembles a FEMA gasifier to meāknown as a tar producerāproceed with caution!
Daniel,
If you do decide to try the SimpleFire, I invite you to check out my thread: Toyota Corolla Charcoal Vehicle Gasifier Project. You might scroll to the end and print out a copy of the most recent brochure.
Car engines and larger engines in general can tollerate some tar as the valve train is much more tollerant. Thicker rocker arms, stiffer springs, presurized oil systems, larger diameter push rods etc. Todays modern single cylinder engines are nearly impossible to wood gas. They cant tollerate very much tar if any at all espicially with a splash type oil system. Plus they are not built sloppy like the old days.
Oh, trust me I know wayy to much about this hahaā¦ What i didnāt tell you is thatI have put quite a few hours on a generator with my crappy prototype i made a couple years ago( documented earlier in this thread).Iāve ran the generator a good while on that hunk of junk, and to make things worse, on big chunks of straight pinewood against all suggestions. It did tar it up of course, to the point of the intake valve sticking within two hours of runtime, or first cooldown. I cleaned it multiple times back then and just put it back together for another run. This was part of my regular maintenance LOL.
Must say im amazed at how much crap would collect in the valvetrain of that thing before it even missed a beat
What im trying to say is that im not afraid to let a little tar through every now and thenā¦
), just something that I can tinker around with and get a few hours of generator runtime.