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Wood gas vehicles: firewood in the fuel tank (lowtechmagazine.com)
144 points by aphextron 9 months ago | hide | past | web | favorite | 67 comments

There was a talk from the Royal Institution just uploaded yesterday (talk was in June), The Apocalypse and How to Avoid It[0], where Lewis Dartnell (author The Knowledge[1]) describes a gasifier stove you can make from a couple bean cans, and also brought up this gasifier engine technology and how it was used in London during the Blitz. This article has a ton of useful information that makes for a great followup.

Also at the talk were Vinay Gupta (Ethereum), Rosalind Eggo, and Hugh Lewis discussing different avenues to potential Apocalypse and their likelihood, etc.

[0] https://www.youtube.com/watch?v=FPxBhqonZEQ

[1] https://www.amazon.com/Knowledge-Rebuild-Civilization-Afterm...

As famously seen in dads army when they converted Jones the butchers lorry.

I saw some of these in use while visiting DPR Korea. We weren't up close, but the government tour guide confirmed that they were wood-burning trucks. Sadly I was not allowed to photograph the trucks. Like the article mentions, deforestation is an issue they can cause, something Korea suffers from greatly.

>Like the article mentions, deforestation is an issue they can cause, something Korea suffers from greatly.

To be fair, that is something that almost every single developing nation in the history of human kind has suffered from greatly.

When resources were scarce during WW II in Germany there were various kinds of wood gas vehicles. Here is a video of a 1942 tractor:


From what I heard, it was the same in France, with various vehicles converted to use wood gas too.

Important downside explained half way through: "if we were to convert every vehicle, or even just a significant number, to wood gas, all the trees in the world would be gone and we would die of hunger because all agricultural land would be sacrificed for energy crops."

Energy crops (subsidized by the government) has already replaced agricultural land for Ethanol fuel production, up to 1% of cultivated land worldwide being use for it.

In the last years of WW2 I think Japan chopped down the last of its trees to make a bit of aviation fuel.

Wait, what? There's absolutely no evidence that "Japan chopped down the last of its trees". Why would you say such a thing? You enjoy lying on the internet?

I saw it in the documentary series “The world at war”. I think the episode about Kamikaze fighters. Japan had virtually no oil supplies. Here’s an article about it. http://thenexthurrah.typepad.com/the_next_hurrah/2006/05/the...

Ok they don’t chop down all of their trees. Of course they still have trees.

Why am I laughing so hard at this?

I'm pretty sure there are pre-WW2 trees in Japan.

It appears that about 12.5% of Japan's land area is old-growth forest. [1] However, I believe it is also true that there was a fair amount of deforestation in the WWII period, and that today, the majority of the forest is modified or plantations.

[1] https://rainforests.mongabay.com/deforestation/archive/Japan...

Politicians in Sweden after WW2 had interesting mindset. They really tried to prepare the country for various worst-case scenarios. Researching wooden gas for cars was one thing.

Another is how they investigated if they should make own nuclear weapons. They decided not to after getting assurances from industry that they can make an atomic bomb within months if needed.

I wonder what other possibilities or backup technologies they considered?

  coal monoxide is a slow burning gas
I've never seen anyone refer to CO as "coal monoxide" before.

It looks like the author's first language may be Dutch, where carbon monoxide is "koolmonoxid" and "kool" can mean both "coal" and "carbon" (although there are more specific words for coal such as "steenkool" = "stone carbon").

Same in most Germanic/Scandinavian languages I believe. Carbon and Coal are synonymous.

Coal as in coal power, coal barbecue, and the element carbon use the same word. That’s not a coincidence.

Apart from some exotic forms like diamonds, trees or rabbits (less pure), coal is how we normally encounter carbon.

In German "Kohle" means coal, and "Kohlenstoff" is carbon. It's not the same word.

(But carbon monoxide is "Kohlenmonoxid")

But "Kohlenstoffmonoxid" is the actual correct term. https://de.wikipedia.org/wiki/Kohlenstoffmonoxid

"Kullos" = "coal fumes" is a term for carbon monoxide in Norwegian.

>Apart from some exotic forms like diamonds, trees or rabbits (less pure), coal is how we normally encounter carbon.

Also graphite. But yeah, coal is basically the purest form of carbon in common bulk usage.

The same in Polish, which is a Slavic language - Carbon Monoxide is "Tlenek Węgla" - and "Węgiel" literally means coal.

Same in Czech. "Kyslicnik uhlicity", and "uhli" means coal (plural).

In Russian, Carbon is "Uglerod", whereas coal is "Ugle". CO, when not referred to by its colloquial name, would be "Uglekislorod" - literally, Coal-oxide.

I’m not saying this is common knowledge, but it’s not a new idea: https://archive.org/details/FEMAEmergencyGassifer , https://www.nrel.gov/docs/legosti/old/3022.pdf . Then again, the fact that the article focuses on WWII cars says it’s not a new idea.

Could we make it better though? a lot of heat must be lost gassifying the wood? Perhaps we could use that for thermometric power generation too.

Possibly. But harvesting that heat directly to 'motion' would probably not be feasible. Storing that on batteries may be better, as they can be slowly trickle charged, but provide a lot of power when there is demand.

I think it's definitely common knowledge to Europeans who would have direct cultural awareness of this due to the impact of WWII, however this is mindblowing to a North American.

Mother Earth News had an article about this: https://www.motherearthnews.com/green-transportation/green-v...

Urea/diesel hybrids would be fun, since every modern engine has to use urea for SCR anyway.

This will make for an excellent premise for a post-apocalyptic story, where eventually the organic biomass starts being over consumed. Basically "Soylent Green" but with cars.

Nice thing about wood power is that as long as you have a sustainable source of wood, you're 100% solar-powered and carbon neutral. That is to say, it's a source of energy that is (can be) non-fossil, nor derived from any fossil sources, and which recycles it's own CO2 emissions.

There are very few other alternatives that can claim the same. Perhaps Hydro? Solar panels don't offset their construction CO2 costs, and in fact almost can't even pay back their own construction energy costs if you factor in batteries plus materials, mining, and shipping.

>Nice thing about wood power is that as long as you have a sustainable source of wood, you're 100% solar-powered and carbon neutral. That is to say, it's a source of energy that is (can be) non-fossil, nor derived from any fossil sources, and which recycles it's own CO2 emissions.

As long as you're happy pouring carcinogens into the air, sure. Also, compared to oil or coal there's not much energy in wood, so it doesn't scale very well.

There's a lot of energy in wood compared to coal. Wood has around 2/3 of the energy of coal by mass. What do you think coal is made from?

Charcoal is made by burning wood in a low oxygen environment, driving off water and organics, while carbonizing lignin, cellulose, etc. Coal is a petrochemical mass formed underground from organic matter over long timescales.

Isn't most of the mass of wood water?

Fresh wood contains ~50% water (up to 70% for certain species), 'dry' wood lies around 15% water. Depending on the type of gasifier you can feed it anything between fresh from the tree to kiln-dried wood. Starting a gasifier requires dry wood or charcoal but once it is going it will do a lot of the drying itself. The reduction process in the lower part of the hearth - where the gas production goes on, reducing CO2 to CO - can also reduce H2O to H2. The end product of a wetter wood will be gas with a higher H2 content next to the CO which forms the main combustible component in wood gas. Yes, wood gas is mainly carbon monoxide and as such highly poisonous, you do not want to start a gasifier in an enclosed environment nor open an unvented gasfier in such.

Dried wood suitable for burning is around 20% water at most, else it won't burn with much heat. It can go down to around 6% IIRC for kiln-dried wood suitable for construction.

Boiling water costs a helluva lot of energy. Do these engines recover that energy?

How would they work if they didn't?

At low efficiency.

You can get power out of wood/cellulose without combustion byproducts.

If you turn the wood to charcoal and only burn the syngas, it's even carbon negative. Charcoal is stable for hundreds or thousands of years when buried. It also improves the soil.

I think this is/was a theory on what caused the little ice age — people making charcoal.

You're wrong about solar panels - they have an EROEI (Energy Return On Energy Invested) of between 4 and 15 times, depending on how you calculate it.

You’re definitely right about EROEI, but I interpreted the parent as saying that solar panels literally don’t recapture the CO2 required to make them, which is true (if not entirely meaningful).

Solar doesn’t reduce atmospheric CO2, it just offsets other production of CO2.

It’s a CO2 emitter actually, since aluminum, glass and silicon all require high heat to make, and we presently do that with natural gas. It may offset its own production emissions by replacing dirtier methods of power but if we switch to all-solar they will be emitting CO2.

I have never seen a discussion about the real sustainability of biomass but I would be curious to know something. OK, the CO2 it emits gets recycled and in a stable biomass-burning world cycle, more CO2 will be emitted but also more trees will grow so it should balance out.

Would that not, however, durably increase the baseline CO2 levels? Sure it is sustainable but do we want to sustain a 500 ppm level? Where would it bring us if the whole world switched from oil to wood?

There is not enough wood to switch over from fossil fuels anyway. We burn incredible amounts of coal and oil.

Gasifiers can run off of many types of biomass. Corn husks and other agricultural waste is a big source besides wood.

Still release a lot of syngas, which, if it was on world wide scale wouldn't be good.

The whole point of gasification is the production of syngas. You don't vent syngas to the atmosphere for the same reason you don't pour gas on the ground. Burning syngas doesn't have to emit carbon monoxide, a catalytic converter like on almost every car out there would work just the same to clean up the emissions.

I find myself pondering the efficiency of removing the gasifier from the vehicle and instead handling it similar to LNG is today.

Would a steam engine make more sense? Then you could run it on anything.

In order to be efficient and powerful, a steam engine needs high-pressure steam, which can only be safely contained by thick, heavy boilers and pipes. This makes miniaturization of steam engines for cars difficult. Gasification of wood allows you to keep the benefits of the internal combustion engine.

I think the bigger issue is adapt vs rebuild.

The Doble steam cars are at least on the cusp of practical.

(they are very high maintenance compared to modern cars)

Thanks; I had never heard of the Doble Steam cars until now. I found this video of Jay Leno driving one.


An ICE car of the same era is also high maintenance as are say cars from the 60's

Modern boilers are coils of thin copper tube that heat up quite fast.

You can run a gasifier out of almost any biomass, coffee grounds, wood, leaves, corn husks. Then with minor modification you can run most cars on the resulting syngas.

I knew an elderly chemist/inventor who told of how he once converted his wife's car to run on cocoa bean husks. He said you wouldn't know the difference except for the slight smell of chocolate as you drove around town.

I want one of those "Mr Fusion" devices from Back to the Future for my car (and my house too, now I think about it).

I wonder if you could power a turbine with wood.

Yes, you can. A few people have built wood powered jet stoves, using car turbos:


No power takeoff from the turbine in this case, of course, but the principle is sound.

Oh wow. I had been thinking about such a device for a couple of years now, great to see one in action.

The main problem is refueling, because the combustion chamber has a higher pressure. With a liquid fuel, you just spray it in at pressure, but with wood that isn't possible.

... refueling: I'm rather certain that there are wood pellet stoves and furnaces with automatic feeding.

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