Charcoal powerd moped


Fitst let me introduce my self. Mi name is Kristijan Leitinger, I am 19 years old and I am working with woodgas for about 6 years now.
I have experimented a lot with wood gas, charcoal gas and last year for my final school practical asigment (chemist school) i build a gas to liquid sistem that turned wood gas to syntetic gasoline.

And now my current project;
I got my self a TOMOS APN6 moped. It has a 50ccm, 2 stroke air cooled engine. I know you might say not an ideal choice for woodgas but i decided for it becouse they are practicly undstroyable and they are made in our contry, Slovenia, so there is no problem for spare parts. It is allso quite easy to increase its power, in fact most 10 year olds here spend most of there afternoon tooneing and driveing those mopeds.

The moped has 4 gears but it is pisible to put a fifth geer in so i did this. I allso changed the engine-to-wheel chain ratio for more torq for steep heals.
The compresion rate was increased from 9:1 to 13:1.
The cilinder was grinded to have 60ccm now and a new, better piston inserted. It goes like hell on gasoline;)
I am currently instaling an oil injection sistem becouse it uses premix now.

I built an experimental charcoal gas generator and it was runing nicely on charcoal, but a small hill killed instantly. Then i tried a water injection sistem for the gasifier and the power increased drasticly. It worked well but it was to small, lasted only about 15 minuts.

So it was time for a new generator. I got my self a 25l sheat steel drum. The reaction chember was made out of an 15cm squere pipe, screwed in the bottom of the drum. It is a crossdraft sistem. the gas goes in a cyclone filter and thain in a copper pipe cooler.

It works great but i have a problem now. I wuld realy like to put a watter injection sistem for the gasifier but i dont know how to dose the watter. The priblem is that with a fixed drip velve you get some condens sucked in the engine when the rpm falls, resolting in further decrese of rpm and so on.

So the queation. How does one regulate how much watter to put in?

Thank you for your help!

Hi Kristijan
Some photos and video would help a lot to giving some suggestions .
But it sounds like a really great project and sounds like you are not scared to give it a Go !
Thanks Patrick

Just finished my oil injection sistem. I put a scooters oil pump on, works like a well oiled machine;)

I will try to take some photos tomorow and a video when its all done.

Greetings KristijanL.
Reading your topic title I thought “Another crazy unrealistic person”.
Reading your introductive experienced based posting; No, a very interesting realistic person.
To loaded run an IC engine on charcoal made gas commands respect.
To modify the engine specifically for this and run test means you are a DOer in Life.

The old way to moderate moisture amount into a charcoal gasifier was to use the gasifier variable heat output to steam convert the water.

Think this way. Pipe your HOT produced charcoal gas through a sealed contaner of water but not directly exposed to the water.
Then bubble up the gasifer inlet air through this container of gas heated now steaming water.
The more gas demand flow the hotter the water and the greater the steam production will be.
The more the gasifier demanded flow the greater the air bubble flow to carry in this steam to the charcoal reaction.
Old and slow system will still work once you get it set up.

A faster responce system would have to measure the produced gas flow rate and proportionally introduce, or withhold the water.
If you can measure either the air in or the gas out volumns a varible speed controlled DC motor water pressure spray system would do it with faster responce. Get very complicated.

Steve Unruh

Hi Kristijan,
You might want to check out the posts in the charcoal section for some ideas. Personally I avoided using water injection because I found too much of it was ending up unreacted in my filters and as you mentioned it is hard to meter. I use exhaust injection to moderate the reaction and return some CO2 and water vapour to the reaction. As load increases exhaust density increases so it automatically adjusts for you. As a side benefit for your situation since it is a two stroke the oil rich exhaust might add some power. Search out Gary Gilmore’s postings on the charcoal side for more on this…
Best regards, David Baillie

Hello Kristijan and welcome to the DOW ( drive on wood site )

You might want to follow what my fried Martin is doing with his bike . This is his thread below .

Thank you all for your help I realy aprichiate it!
Just test fired the sistem. Works realy great! I installed a very soffisticated water injection sistem for a test run, thats my girlfriend with a small water spray;)

Does a return exhsust sistem add any power to the engine or is it mainly for the temp control?

As promised, the pics:

Hi Kristijan,

I work now with an pre-heating coil for the intake air. The bottom i can leave open for liquid dripping out incase the temperature is still to low.
The drip can be adjusted ( on -off ) by using the vacuum of your engine and the vacuum in the gasifier.
( 2 valves, no vacuum in gasifier and high vacuum in intake manifold of the engine then no water or eventual reduced water )
The hotter you can pre-heat the water, the more you can use without having condensate to much.
60CC also needs a small nozzle in your cross-draft system, what size you are using now ?
The most helpfull tips you can get from Gary Gilmore, one important that will benefit most is the sizing and grading of the charcoal.
Small and uniform does do the trick.
I learned that from Gary and David.
Pictures looking great, waiting to see the video’s … :stuck_out_tongue:

Hi Kristijan
In your first post you mentioned you had a wood gas to synthetic gasoline project, if you have the time I would love to hear more about that project?
Thanks Patrick

I have a 15mm stainless nozzle in the reactor but it burns out quote fast. Im thinking about something cheramic…

Gas to liquid proces is a catalytic reaction, called Fischer Tropsh reaction. CO and H2, both components of wood gas, react on microscopic cristals if iron to form gasoline and water. It seems simple but it gets complicated;)

Hi Kristijan
Can is be done at home or is it a lab thing only?

Koen and others use ceramic fuse holders as their nozzles .

Thanks Patrick

Anynting can be done:) but it isnt practical or economical on a small scale. Only about 5% of wood gets converted to gasoline becouse of nitrogen delution and other factors. Factory size reactor is a complitely other thing.
Ive seen Koens videos and pics but unfortunaly fuses are made diferently here. They are to small… Must find something else…

I agree on charcoal size its very inportant!

I am thinking about injecting both steam and exhauat for a test

Hi Kristijan,

My smallest size i use is 6mm diameter and does the job quite good.

Exhaust + steam, then should be very hot before entering in the glowing charcoal… otherwise to much dilution with CO2 and H2O in the gas…

Just finneshed another test here… 50% oxygen + 50% CO2
No dilution with nitrogen …
It looks all CO2 has been converted into CO…
I have a Carbon dioxide killer … :stuck_out_tongue:

CO2/O2 has to be great but i wuldent drive 2 2m long botles of high presure gas with me;))

Will try out the fuses hope it will wirk…

Over on the yahoo charcoal group some people are using a single firebrick with a bored hole in it to act as the nozzle when the air intake is from below. It shows great promise. Worth checking out if you have not. Lots of older conversations about nozzles and injection…

Hi Kristijan
You could go find a pottery studio or a potter and custom make nozzles, get them fired and try them.
Another option is electrical insulators, or telephone pole insulators.

Thanks for the info on the FT process. So you can only make 5% of the wood in to fuel ( is that by weight or volume ?)
What other products do you get ?


@Kristijan CO2/O2 has to be great but i wuldent drive 2 2m long botles of high presure gas with me;)) He is using the bottled gasses to have a “pure” starting point to be able to measure the efficiency of the unit and get accurate measurements. It would be used for research purposes only, not for practical use.

I have some clay will try to make some nozzles my self thanls for the idea!

Its hard to say how much gasoline do you get from a Kg of wood becouse there are so many factors. Quality of gas, reaction presure, temperature and so on the fact is that it just isnt economical on a small scale. It might be practical if you wuld use pure oxigen in the gasifier so there is no nitrigen in the gas.
You get lots of products prom gaaoline to parafin and alcohol

I was thinking about puting a decondensor of some kind on the unite. Had something like that on my previus wood gas unite. A 10l plastic barrel filled with stainless… I dont know how its called in inglish… Its for dishwashing:) anyway, it worked well but culd be inproved. The water vapor condensates on the large surface area and just drips down where it can be drained out. Tar allsow condensates with water.

How much preignition shuld i put on the engine?

Hi Kristijan,

If you use charcoal, only a minimal amount of tar will occur.
Depending the temperature you work you will have more or less water-condensate.
keep the amount of charcoal high enough, but you are working cross draft ?
If you ad a tiny bit of water drip, or a % of exhaust gas , then you will not need to advance the timing.
Just keep the gas quality uniform, run it with your engine, and then check if you need to change…
Air humidity also ads to the Hydrogen content. The hydrogen will give you a higher flame speed, this will eliminate the need for timing adjustment.

Woven stainless steel scrubbing pads KirstijanL. Common steel wool scrubbing pads would rust corrode too fast. There are woven copper metal scrubbing pads also - still be too reactive. Plastic woven scrubbing pads - too temerature sensitive for hot gases impingement filtering.

Good advices KoenVL.
Thank you for teaching me the English word " dialogue" - denoting a process of common reasoning for understandings resolution. Much more agreeable than even discussion.

Steve Unruh