What am I thinking?

You don't need fuel cells.  Just use Stirling Engines.  Didn't I come to that conclusion already?  A Stirling Engine will allow external burning, which will in turn eliminate carbon monoxide, which is a poison.  It will produce water vapor and carbon dioxide.  These can be recycled in an enclosed area.

But nobody, except perhaps Dan Rojas, makes Stirling Engines for sale.  Well, if it is to be Dan Rojas, then it will be Dan Rojas of Greenpowerscience.

But wait.  I remember a company called Infinia, which made solar dishes of about 3kw.  Not really interested in that, but would like to have access to their Stirling Engines.  It appears that Infinia was bought out and goes by the name of Qnergy.  As usual it seems, they don't have a product right now, but promises one in 2015.

It seems that Stirling is the way to go for me for what I'm trying to do.  Fuel cells may be out the window.

Update ( about two weeks later )

Qenergy has developed a Stirling engine that will run on wood pellets.  I'm thinking that my idea of making pellets out of wood and algae may work in this engine.  The Stirling engine will bypass the need to make a gasifier with all of its complications.