Viability of a gaseous propane powered engine?

[Enthalpy]

The dioxide emissions favour the use of propane because if you don't use it, it gets torched at the production well.

 

The efficient use of propane needs an adequate engine.

[DanTrentfield]

The dioxide emissions favour the use of propane because if you don't use it, it gets torched at the production well.

 

The efficient use of propane needs an adequate engine.

Problem is the adequate engine. I thought this would be a great idea at the start and that it would turn out to be worthwhile, but all it has done has sated my own ravenous curiosity on the subject of alternative fuels.