Practicality of wood gas electricity.

[maple flats]

ON an episode of Mountain Men on I believe the History Channel, Eustace Conway, one of the characters (and I do mean Character) made a gasifier to power his old pick-up truck. Look up Gasifiers, there is really lots of info.
In fact back in the 40's or 50's the US Ag Dept printed a booklet showing how to build one to power a farm tractor.

[Al_Smith]

Eustace comes up with all kinds of things out of the ordinary . I get amused watching his antics which usually work  .One of the best was using hydraulic pressure from a stream to run a small electrical generator using a water turbine and a small three phase motor .Years ago Mother Earth News had an article of a co-op in West Virginia doing the exact same thing using a larger motor, I think 75 HP .
These are not new ideas ,just revisted .For example at one time in the huge steel miles they used "producer gas " using giant horizontal cylinder low speed engines to turn giant generators to supply electrical power to run the mills .In those days the electrical utility companies did not  have a capabilities to do .Plus the producer gas was just a by product of burning coke in the blast furnaces that would have otherwise just have gone  up the smoke stacks any way . Free fuel in a way .

[peakbagger]

It takes a lot of elevation head and volume to generate enough power to drive a sawmill. The Eustace segments are edited heavily and its not beyond the show to take liberty with the facts to make a story. He along with the other folks on the show are paid actors and work off a script. Its likely that his income from the show would have easily paid the various debts he owes but that ruins the story. There are at least two water systems shown in the show over the years. His water line for the garden that he has to fix with the blue barrels is way to small to run a turbine unless he has a very high elevation head but the turbine that is shown in one show is not the type setup for high head. In another episode they have plugged line and its its much larger pipe, possibly 6" diameter.

With respect to wood gas engines the btu content of the mostly Carbon Monoxide gas being produced is quite low, yes it may power a truck but it will be way down on power. The wood has to be bone dry or the gas will be wet.

The steel mills still use producer gas but now they run it through gas turbines, producer gas is more volatile.  

[mike_belben]

i think you guys know that im willing to work pretty hard to make something from little if the long run works out.  every time ive looked at wood gas for even small industrial use it has come with too many complications.  the gas quality has to be very specific for long term use in a combustion engine without causing it harm or wrecking the oil with acids and stuff.   its fine for a lawnmower or some quick blast in your hemi to get youtube fame but i dont think the energy input to output ratio pencils out for reliable industrial application unless you are a big pocket sawmill willing to have the system engineered by pros who fly in and then you build whatever systems they say for consistent gas quality that may STILL be corrosive.  


i think wood fire into water into steam is vastly, vastly more sensible.  it built a lot of big nations, afterall. 

[Al_Smith]

That hydro turbine thing they use the same method to raise the pressure they once did for hydraulic mining in California .Start off with a big pipe and through a series of increasingly smaller pipes increase the velocity which in turn raises the pressure .
I forgot the specifics of that Mother Earth News article from decades ago but I believe the final pressure was 200 PSI in a 2 inch discharge .What I do remember about water pressure is it's 44 PSI per 100 foot head .To get enough elevation you might be able to do it in the mountains of North Carolina or Colorado but never in Ohio .
Regarding the Eustace series I'm certain being a so called reality TV it's highly scripted .Entertaining though I must admit .I wonder if he still has Wallace the old mule ?

[mike_belben]

Converging tube diameter will absolutely raise the velocity of fluid flow in a closed conduit but it will lower the pressure, thats bernoullie principle.. Pressure and velocity are inverse and ive messed with this a good bit in race engines, it is surprisingly true.


in a pelton water wheel generator like is commonly built, the higher velocity jet blasting the cups in an open or vented to atmospheric pressure enclosure, will apply more energy to the rotor because of the nozzle velocity increase. So youve got it right, and it does work.. just need some tweaking on the tiny detail.. Its inertia of water mass caused by velocity, impacting a cup and dissipating its stored energy into the rotor.

[peakbagger]

Ram pump technology was used a lot in hydraulic mining. Its pretty simple to build out of parts from Home Depot and work remarkably well. It takes a lot of flow with low elevation head and converts it to a higher pressure lower flow. The original cast iron versions could run for decades but most of them seem to end up in antique shops. 

[Al_Smith]

I've never lived anywhere with enough elevation to use the principles of hydraulic mining or Pelton under shot turbines I do however own a 3000 PSI pressure washer and it is a good excavator in some applications .Some times you have to think outside of the box you know..  

[Al_Smith]

This wood gas thing if it hasn't already been mentioned was used during WW2 in England to run busses etc ..I doubt they ran very well nor did the engines survive very long but they made do with what they had .
For that matter you can made a sort of crude oil from organic material under heat and pressure .Then run it through a vacuum distillation unit and get a crude form of gasoline .Of course in all that experimentation you could blow yourself, or parts of you into the next county if something goes awry .I don't think I'll delve into it myself . :D

[mike_belben]

its been a long time, but i think i remember concluding that the feed stock quality on wood gasification has to be huge and identical so that whatever ill come with it, could be adjusted for one time and managed.  so a mega mill with the same wood all the time can develop a program and eventually arrive at a stable fuel that doesnt wreck engines and engine lubricant from all the acids and CFCs or whatever junk is in the smoke.  this may require scrubbers and treatment conditioners and lots of labby sciency stuff.  more than i could tolerate.  expensive to do long term on an expensive engine without ruining it.  


so just tossing in any old willy wonka roadside junk (which is what alternative energy noobs always think.. ill just suck raw frenchfry oil from any barrel into my greasecar conversion) is not gonna last too long.  and that is the situation with waste veggie too.  refining the fuel is a long term process.  we get a lot of mega scale value out of our gas stations, even at $3 a gallon, compared to trying to make your own.  same for $60 a gallon maple syrup or $12 two by studs.  its outrageous, but try making your own some time!  there are major up front investments and labor inputs to get that first gallon, first stud, first mile. break even is pretty far into the future. 

[Paul_H]

Engines run well on wood or charcoal gas and the use of them during WWII saved thousands of lives and over a million woodgasifiers were built by companies such as Electrolux. Without fossil fuels for agriculture and transport starvation would have occurred on a massive scale.

The present day wood gasifiers are far better at producing clean gas than the Imbert style from WWII and they would make perfect sense today in an emergency situation. Presently there are many woodgas and charcoal vehicles built and driven in the US and worldwide. In remote flycamps where wood fuel is available  woodgas would make more sense than flying in barrels of fuel over long distances.

I like my gasoline but driving on woodgas is fun and handy to have if needed. I've driven a couple thousand woodgas miles on my 82 F150

Charcoal gasifiers that produce clean engine gas can be built in a day if the materials are on hand. We run a 12HP garden tractor with it and pulls quite well. Making a 1/3 of a barrel of charcoal takes little time to load but longer to grind and sort.

Here is a video showing the diversity of the wood gas vehicles from WWII

WW2 Woodgas History "We'll Meet Again" - YouTube

[mike_belben]

neat.  that makes you and puffergas for the only two ive encountered who have done it.  most are just talk and internet links. 

[Paul_H]

https://forestryforum.com/board/index.php?action=profile;u=8539  Member Ron has built a woodgas truck and a farm tractor and him and his family have hosted a few woodgas large gatherings.

https://forestryforum.com/board/index.php?topic=57556.msg906294#msg906294

[Al_Smith]

It's all related to what you want to do regarding a lot of alternatives ..You  could build a spring house instead of paying the power company for electrical power to run a refrigerator  if you wanted to ..I just would not want to walk a quarter mile  to the spring when my cold beer is in my garage 20 feet from where I'm sitting typing away with one finger .--Besides that I don't have a spring ----
Plus you could cut firewood with a bow saw ,I have one .I also have 40 or 50 chainsaws .I'll never wear out my bow saw .

[Paul_H]

Each to his own,I heard of one crazy begger that made a cylinder sleeve for chainsaw :D ;D

[Joe Hillmann]

I would say wood gas is only useful for making electric in fairly rare conditions.  I build a wood gas generator for a 5 hp engine.  It worked but cleaning the gas and the need for bone dry wood of the right size made it very difficult to use.  If the wood had a tiny bit too much moisture, or the gasafier was running too cool it would gum up the intake valve with tar and the engine would have to be taken apart after the run to clean it.

  I assume charcoal would solve that problem but then you have to make the charcoal.  If you can make charcoal and harvest the heat from making it to heat your home it would make it more worthwhile.

If you want power for a large number of hours the maintenance, and wear on the engine and gasafier will be high enough that you will soon decide you are better off using some other method to produce your electricity.  Solar is cheap.  Wind works in some locations.  Moving water has lots of power.  Battery storage is where things get expensive.  Reducing your power consumption and timing your power use at times of peak production will allow you to use a much smaller battery bank than what you need at first glance.

[Ianab]

Have to wonder if a Sterling cycle engine wouldn't be more practical as a generator?

You have a wood fire going to produce heat / hot water, and use some of the heat to power a small Sterling engine connected to an alternator / battery etc. You aren't worried so much about the efficiency as the rest of the heat is being used for other things. 

Like Joe says, if you are off grid you want to minimise your electricity usage. The essential things like lighting and electronics can be made fairly low draw. The heating / cooking / hot water are the high load things, so take them out of your electric system. 

[Al_Smith]

Each to his own,I heard of one crazy begger that made a cylinder sleeve for chainsaw :D ;D

guilty as charged  :D

[Magicman]

Scroll down to Ron57's wood burning truck:  LINK

I wish that there was a video.

[pineywoods]

i built a small wood gasifier using 2 old propane tanks. The idea was to use wood gas to run a generator for standby power. Then had one of them "aha moments" why can't we store woodgas or convert it to something that would be long-term storeable. There is a nearby chemical plant that uses natural gas (similar to wood gas) as feed stock to produce several different products some of which are flameable liquids. So ran my idea past an engineer there. Turns out the germans developed such a process during ww2 to produce diesel fuel from coal. Requires pressures above 2500 degrees at temps above 1000 psi in the presence of catalysts. Definitely not suitable as a back-yard project. 

[peakbagger]

Fischer Tropsch process.

[Al_Smith]

I'd imagine about anything in raw crude oil would be in coal, peat, wood .It's just the method of extraction as to  what you might get out of it .Good exercise in the fields  of physics and chemistry .Interesting subject for certain