Try something like the WK gasifier, just the fire tube section, with a shroud to concentrate and flare the gas instead of cleaning, cooling, and “popping” the gas in an engine.
Give it enough depth below for the slipped char to cool before removal.
Thank Joel S for the design. So simple that the only additional requirement to truly enjoy the process is a pretty gal to shovel “fuel” in the top and auger out cool char from the bottom, into a wheelbarrow ;~)
If you only see one image, I will try to upload the second image with more details in a second post. I am new user and only allowed one pic per post.