Hello everyone. I fully understand that downdraft wood gasifiers are a superior design to updraft gasifiers for numerous reasons, specifically their tar production.
However, I am very interested in using “wet” wood as a fuel.
That being said, I would like to use an updraft gasifier and clean the gas afterwards. To this end, I am thinking of sending the gas (After it travels upwards through the fuel) through a cyclone, then through a nickel foam catalyst which would be contained in a semi-annular tube around the oxidation and or combustion zones. From there I would do some additional polishing of the gas.
Is this a sound idea? I get that updraft gas is extremely dirty. I just want to gasify wet wood. I want to break branches off trees, shred them, and gasify them.
Depends what you want to use the gas for. Heating for water or space heating might work but unless you enjoy tearing down engines and unsticking valves I would stick with downdraft and dry wood for engines.
May have been others I don’t know about but since I’ve been on the site only Joni from the Ukraine was able to pick up fuel from the side of the road. I always found that fascinating but I don’t think it was wood full of sap.
I don’t think raw wood updraft is possible - wet or dry fuel. It would clog up everything pretty fast - piping included. Flaring straight from a hopper is ok for a little while, but that’s about it.
Even with dry fuel and downdraft we struggle keeping temps up to turn enough steam to hydrogen. I guess you could run wet fuel in a downdraft gasifier with enough condensation ability in the hopper, but it would affect gas quality and efficiency.