The device Hans asked about is called a “digester”. It produced methane from the breakdown of the cellulose in the wood. Plans (albeilt old) are still available from Lindsey Publications - a cool place for old technical stuff. BTW, I have no affiliation with them - I just like their stuff.
I saw one of these at the Peterson Automotive museum in Los Angeles. It’s a beautiful truck. There’s a picture in the link below:
From the Peterson website: “The same circumstances that made electric cars viable in Europe during World War II, also made vehicles that burned coal gas practical. Also called “wood gas,” the fuel was created by partially burning wood or coal to produce a gaseous substance that could be used for combustible fuel. Although the fuel gave poor performance and the gasification process created excessive air pollution, it was deemed acceptable during wartime because it allowed a large number of vehicles to remain operational with the addition of a special gasification apparatus and a few straightforward engine modifications. Bulky and unattractive, virtually all gasification systems were removed from vehicles immediately after the war and cars so equipped are now extremely rare.”
Hans is not crazy. GM, Ford and Mercedes manufactured wood gas mobiles during WWII. They operate by passing oxygen and water vapor over coals. The carbon dioxide is reduced to carbon monoxide and water vapor is reduced to hydrogen - then both gases can be burned in a standard internal combustion engine. The gas mix is about 40% combustible.
These type of engines were largely referred to as Imbert Gasifiers (named after the inventor Jacques Imbert).
Instructor - Renewable Energy (Central Ohio Technical College)
I’m disappointed - you guys went to MIT & went to a couple of teacher colleges. It’s wood gasification!
I remember hearing about these back in the gas crisis of the 70’s when we were wood gathering hippies. I looked it up and sure enough the technology goes back to the 1830’s at least. Anyway, we got side tracked and didn’t go any further with converting our woods trucks but the info is out there as the guy above said “Google It” ( I had to look it up in the 70’s you can get more information now in less time that it took me to get to the library)
I saw one of these in North Korea in the early 2000s and “googled” the following:
North Korea runs on wood-burning trucks 5
BY CHRISTOPHER MIMS
18 JUL 2011 12:36 PM
If you’ve ever wondered what we’ll do after we’ve run out of cheap oil, other than eat each other, you have only to look to the Democratic People’s Republic of Korea, a.k.a. North Korea. Ever since the shipments of crude from the USSR and China dried up, they’ve had to improvise.
So Dear Leader has once again demonstrated his Everlasting Beneficence and Ingenuity, pioneering the use of trucks that run on firewood and/or coal. Nowadays, if you see a truck, especially in a rural area, it’s probably running on “wood gas.” That’s carbon monoxide and hydrogen gas, produced by burning coal or wood in a low-oxygen environment – the resulting gas can be pumped into a diesel engine and in that form is a replacement for liquid fuels. Here are abunch of images of these wacky, steam punk-ish vehicles. And a video.
The use of wood gas to run engines was invented in 1839 and it was quite popular during the fuel shortages of WWII. Near the end, the Germans had half a million vehicles running on wood gas.
But you don’t always want to follow the lead of Nazi Germany, you know? Wood gas is pretty terrible for air quality, and it involves coal or biomass, which is pretty much always bad for the climate.