That is one of the most interesting papers I have (partially) read on them.
This is interesting.
"Another potentially interesting use of producer gas is
to generate electric power using fuel cells. A fuel cell
is an electrochemical device that converts chemical
energy into electricity directly without moving parts.
Fuel cell development is very active at present, and
some fuel cells may soon be available for use with
producer gas."
Have you seen the FEMA plans?
http://www.woodgas.net/files/FEMA_emergency_gassifer.pdfIt does seem as though this is pretty basic, and the designs have been improved considerably since then. It's said about the web that they were a bit prone to exploding, or poisoning peeps with carbon monoxide.