I thought that the name of the game was to produce a fuel that can be used in an internal reciprocating combustion engine.
More precisely, the internal reciprocating combustion engines
already owned by millions of people, without modification of those engines. -Blast, trying to imagine what a methane-powered jet plane would look like.
p.s. I'm also imagining huge "factory" complexes with thousands of cows caged up in rows, a tube feeding them switchgrass at one end and a methane collection unit attached to the other end. *shudder*