Hi,
roughly speaking the project of Francois is very similar to a Mako S gasifier, except that he has a refractory hearth zone and a heat exchanger with water drip.
I really like his sketch. He uses the hot gas for preheating primary air and creating steam. There is no boiler with a “pond” of water, but a drip. So as Kristijan said more a mixture of air and water drips.
I personally would try to replace the water drip with a kind of carburetor to create a fine water mist. Freezing during the run could be prevented with air already heated before the carburetor. At least in mild winter, probably not in Canada or Scandinavia.
I see the same problems as Krisitjan with ethanol .
Til