i just finished building a hybrid wood and charcoal gasifier. it is most definitely a work in progress, although at the moment it does seem to work. here is a video of it working.
what i have is a small updraft wood gasifier unit, which feeds a simple fire charcoal unit. the small hydraulic ram you see is full of wood shavings to act as a filter before entering the engine.
like i said this is most definitely a work in progress, i’m having to use what little resources i have due to a very tight budget. the wood unit is definitely not air tight unfortunately. this setup is definitely more for a proof of concept anyway.
the inspiration for this setup came from something wayne said… “gasification is simply passing wood smoke over glowing hot charcoal”
the idea here is that i could use bigger pieces of wood in the first reactor, which should hopefully pass through the charcoal unit which will hopefully clean up that dirty smoke into engine grade gas. big pieces typically make very dirty, crappy gas, but if it can be be cleaned and have the tars cracked by passing through the charcoal reactor then it would mean far less wood processing would be required. the chunks im running in the video are anywhere up to 6" by 3" pieces of 2x6, so not huge but definitely bigger than ideal gasifier feed stock.
i chose the updraft unit simply because the reactor vessel is not air tight, and even with the engine running i could not get it to pull air downwards through the 1" hole. however, i do remember reading somewhere that updraft units do typically produce higher volumes of gas, but it is very dirty, so possibly the updraft unit may be a good choice to stick with.
the next question is whether or not this combination unit will go through less charcoal than a unit running strictly charcoal, and if it does use less, how much less? substantially? or barely at all? becasue if it doesnt use much less charcoal than a charcoal only unit, then it doesnt seem there would be much point to this.
anyhow, please share your thoughts and possible problems or improvements i could make, thanks!