Americans knew how to build wood burning gasification units to power gasoline farm equipment and cars back in WW2. Its not that hard if you can weld. The tech works and its proven.
http://www.gengas.nu/byggbes/contents.shtml
they were also doing that in WWII Europe esp. France
and Germany.
Called a gazogene or some such..these systems generated
methane, which was then burned in an internal combustion engine.
This process would I presume distill a liquid fuel that
could be used directly with a carb or FI fuel supply system.
Just take care that it doesn’t eat rubber or nylon seals.