Volume of Charcoal to Gasoline equivalent?

Is there a rule of thumb for x amount of charcoal equals 1 gallon of gasoline?

AbeC you can find precise numbers in different DOW library sources.
22.85 pound of gasifier wood equals 1 gallon U.S of gasoline.
As I recall wood charcoal is rated at ~16 pounds per gallon gasoline.

But . . .
But . . . these are open air clean burn BTU energy numbers.
Many variables.
What era of gasoline blended to what octane? For what use purpose? 85,000 (E-85) to 121,000 (WWII German synthesized aviation) BTU’s per gallon depending on formulation, and with/without forced added oxygenates. This factor alone throws off easy numbers.

How are these fuels to be used?
In internal piston combustion engines?
Heat producing burners? Gasoline camping stove and lanterns as an example. I’ve had both.

Best just use 30 pounds wood per gasoline replacement for engines.
And I figure 20 pounds wood charcoal for the same.

Gasoline cut off use, and then no more consumption.
Woods and charcoal keep heat converting on for a time bleeding down temperature. That is real energy produced/fuel consumed and not engine running that has to be accounted for.

Ideal woods and charcoal are at less than 10% moisture. Ha! In the real world you work with 15-20% fuels moisture. Energy conversion loss there versus no-water gasoline.
Different gasifier builds, for wood and charcoal, heat energy loss bleed out at different rates. This will also up your actual consumed /use wood fuels and charcoal versus gasoline in say an electrical generator.

Steve unruh


Abe, my charcoal usage in the Toyota has shown 9 to 10 pounds of well-burned, dry charcoal to be equal to 1 gallon of gasoline. Sorry, I missed the word “volume.” My lower quality charcoal is about 1 pound per gallon volume and goes up to probably a max of 1.5 pounds for a gallon volume.


Sounds about right from my experiances too.

In other words, 1liter equals 1km. Thats how l calculate range and hopper volume. You guys do the conversion, l have enaugh thinking for today. All thats on my night is B&B (beer then bed :smile:)


Although this topic is “Volume of Charcoal to gasoline equivalent?”, the responses in pounds may be useful since charcoals can vary in density.

I’m envious of the simplicity of Kristijan’s European "1 liter equals 1km. I get about 3 miles to a gallon of charcoal in my 20 MPG vehicle.

Here is another “rule of thumb” that can be kind of a mind bender: Wood has 50% more energy per given volume than charcoal and charcoal has 50% more energy per given weight than wood. The charcoal weight advantage and the additional weight of a wood gasifier is why charcoal is the fuel of choice for low-powered vehicles.


And now off grid too. haha. The stove tech is working out well and if combined with solar there is no better way to do this. Get heat from the stove, it makes charcoal, then charcoal makes power with little to no effort. It will be a lot nicer when I get the auger clean out installed.


Haha sure makes things easy when design hopper size :smile:
But there is more! It happens so that 1kg charcoal is allso equal to 1l petrol! Got to love metric :wink:
True on what Bruce sayd on weight and volume vs energy density. If only we culd compress charcoal to pellets efficiently and on a home basis. Hopper wuld compete with a fuel tank in volume!


Well Im not doing it exactly that way. But using the stove for heat and then having it spit out charpellets in process is working!! It actually does not seem to effect the run times. If fact the stove runs cleaner and hotter with the grate active. I think this stove maybe operating more efficiently as it is converter the primary combustion produced Co2 to CO more effectively than ordinary stoves while also cracking the hydrocarbon chains down better. So I dont even miss the expelled fuel in process.

And indeed these compressed charpellets are far heavier by volume than processed lump charcoal. Im not going back to direct wood gasification I dont think. I can offer this full system including this stove tech with a gasifier for less cost than a direct wood gasifier with all the filtering. The advanced controls I developed will work even better on charcoal making it more efficient to boot. :slight_smile:


Oeps, put my pellet installation for sale. Got a potential buyer today… what now , sell or try?

Can’ t say it enough. Wonderfull forum. Learned a lot last year.

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The answer is obvious for me. Try, if it doesent work, sell :smile:

Althugh there is a bit of a catch here. The way l look at it, those charcoal pellets need a binder. They used wood tar in the day (carbonite) but l guess many things culd be used, from starch to tar to waste plastics maybee? And thus, those pellets shuld only be burnt in a downdraft gasifier. Not that thats a problem to make, but it is more work thain a simple updraft charcoal gasifier.


Matt, what did you use for a binder?

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Im not, this is just using off the shelf raw wood pellets like any other stove. The stove combust them like normal except Im using my basic pellet gasifier reactor technology with an active grate just like the engine gasifiers use. The stove then spits out the char pellets for harvesting for charcoal gasification. This justifies buying them for me, as I get both heat and power from them and no fuel processing involve for engine power gasification other than screening out dust and white ash.

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Yes. Maybe. Wood needs a lot of power to get compressed. Maybe charcoal not, since it is so light.

Tar/ condense is produced by the woodstove now. Around two gallons a batch. If I really want to sell, people will want to try before they buy. Hmmm, lets see if I can get it up and running next weekend.

Aaah l see… l have done wood pellet charcoal. Not financialy acceptible but man thats some superfuel for a gasifier

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labor is labor, wood processing at home is not free. The pellets you buy at the store is a bargain. If you enjoy that type of work that is cool. But Ive done it my whole life and my back is shot. I cant do it anymore and I dont enjoy any wood processing one bit. Cutting and splitting wood 12 hours a day for 10 years was enough for me. Ill gladly pay for pellet fuel. Its cleaner easier to store and now I get twice the use out of them. :slight_smile:


Dont get me wrong, l used pellets too. Raw, in my cars. Still only half the price of petrol here, compared.

Firewood prepp, it depends. In my small old non insulated house l burned about 2 cords in a year since we are here, that includes fireing up the stove just to make meals. I can prepare a cord a day without breaking a sweat with nothing but a chainsaw and a axe so thats 2 days of work a year. Thats just clearing the bush and undergrowth wich needs to be done anyway. Kinda no brainer to me. But motor fuel, thats a different story!

I have found it much easyer to throw wood in a kiln and make charcoa then shovel in a mill/sieve device and make tar free engine fuel for a whole month in just a few hours rather thain chunk, dry, package… raw wood wich is still just that. Raw. Tar possibility.

What you worked on is even better. Harvesting motor fuel from a wood stove. What else an you wish for??? Tryed that my self with my greenhouse heater but it wasnt feasable. To litle wood was burnt. But for a house?..


Not sure If or When this will ever exist Or If you can purchase it for any price .

General Product Description: Torrefied wood briquettes for replacement of coal in
power plants and as an industrial solid fuel.
Appearance: Various shapes, including but not limited to, dark brown
cylindrical briquettes (40 to 90 mm in diameter) and
pellets (6 to 10 mm in diameter).
Appearance: dark brown, log-shaped briquettes
Odor: odorless
Molecular weight: 12 g/mol (Carbon)
Physical state: various solid shapes, including briquette (40 to 90 mm) and
pellets (6 to 10 mm in diameter)
BULK DENSITY (briquettes/pellets): 36 to 40 lbs/ft3

Yup Ive learned it took a long time for me. I looked at charcaol gasification at face value and thought it was a waste looked like too much work. Then I started to really analyse all the processing energy involved in running the equipment, time in further processing and started to realize that charcoal is actually easier and isnt as much as waste in the process. Your just using the energy to create the fuels differently and whats so hard about sitting in a lawn chair watching something burn anyways? Right? haha. I like that much better then sweaty labor.

Here is also something to factor considering fuels for heat. Here 2000 lbs of pellets have gone down in pricing to around $220.00 pr ton. A cord of wood varies here but is generally around $200. pr cord or 4000 lbs. But here is the kicker a modern pellet stove is generally three times more efficient than some of the best cord wood stoves available. So in the case of purchasing the fuels. Pellets are actually more cost effective despite cost pr weight as you use less fuel for the same heat value plus those stoves run much cleaner.

I have reached out to a US stove manufacturer for help with the stove to take a further get it tested UL approved and all that mess. So hopefully they will respond.

I have a 8inch flat plate mill with a 22hp engine and we tried making charcoal pellets , we used rice flour as a binder and as long as you can coat most the charcoal it works , but we struggled to get a uniformed mix at the time and i think we blocked the die up a couple of times as well .

Hardwood / pine pellets here in Australia go for around $20 plus for a 15kg bag thats why we bought a mill thought we could make a killing , last month we found someone importing in pellets for $10 we bought half a tonn of fantastic hardwood pellets for our pellet stoves so much easier than making our own . all we need now is a set up like Matts and i think we would be fixed up on all sides .


I have a lot of wood waste on my farm, and we char it to reduce the volume and use it in the garden and orchards.

I have a Kawasaki Mule side by side that I use daily for farm chores. I want to make a charcoal gasifier to run it, so I was just curious how big of a hopper I should plan for.

I use 1-2 gallons of gasoline a week with it. It’s parked in a shelter all the time, stays dry, so it would be nice if I didn’t have to fill the hopper every day, once a week or so would be perfect.