We were very happy to report in Homemade Motor Fuel Through Wood Gasification that our experiments concerning the application of wood scraps for vehicle motor fuel showed promise. But little did we realize, at that time, just how well the unlikely type of solid energy would work in a liquid world.
In short, for a total cost of approximately $125 – as well as a fair quantity of cutting and welding – we’ve put together an effective alternative fuel power system. Besides our wood gas truck move in the future as reliably and smoothly just like any conventionally powered automobile, it can so at zero fuel cost!
(Click here and here for downloadable versions from the construction illustrations.)
A Straightforward Process
Here’s how the system works: Wood scraps (we use chunks that are greater than sawdust or shavings, but smaller than a 6 period of 2 X 4) are contained in a modified boiling water tank, and rest on a cone-shaped, cast-refractory hearth. The recycled vessel is airtight except for a spring-loaded and sealed fill lid, a capped lighting aperture, and an inlet port (the very last is simply a two-inch brass swing check valve, which allows the draw developed by the engine to pull controlled amounts of air into the firebox).
Incoming atmosphere is directed through a series of holes drilled into one shoulder of the discarded wheel rim (which happens to be girdled with a circular band of strap metal and fastened to the bottom of the tank), and supports combustion in the vicinity of the hearth. As the fuel in that area burns, it consumes the oxygen within the air – creating carbon dioxide and water vapor – and forms a bed of glowing charcoal, which collects over a grate suspended from chains several inches below the hearth assembly. (Simultaneously, a heat-induced decomposition zone is produced right on top of the combustion region, driving gases from, and carbonizing, the wood just before its incineration.)
The mixture of CO2 and moisture – in addition to some creosote-is then drawn through a choker (positioned in between the hearth as well as the charcoal grate) and forced into the embers at the lower part of the tank before leaving the gasifier. The choke serves as an aura restricter which blends the various vapors and directs them through the glowing coals, where they’re reduced to the combustible gases deadly carbon monoxide, hydrogen, and – in small amounts – methane. The final product also includes a good deal of nitrogen, in addition to some unconverted CO 2 and traces of ash and tar.
The carbon dioxide and nitrogen are inert, and the like non-fuels pose no threat to the powerplant. However, the tar and ash needs to be removed from the gas or they may produce deposits, possibly resulting in engine damage. So, to clean the fuel, the smoke is first routed through a liquid-cooled densifier (a multitubed heat exchanger flanked by a water jacket and plumbed in to a junk automobile air conditioning condenser that’s mounted in front of the existing radiator), which precipitates moisture and residue from the gas. It passes to a tubular filter that’s  filled with strands of commercial air cooling filament, woven transport padding, or a similar material that won’t disintegrate, rust, or burn, and  equipped with perforated flame traps at its entrance and its exit.