Genesys wrote..

Methanol can be synthesized from carbon sources quite easily as well. The issue with methanol, besides its corrosive nature, is the relatively-severe dearth of BTUs per gallon.

The liquid BTU/gallon measure is but one of a number of possible trades to optimize. Because of its toxicity, methanol has some drawbacks. It was tried in the 80's because it was industrially available. It also tends to put formaldehyde in the exhaust.

The end-to-end energy loss must be factored in, as well as portability, toxicity and availability of engine technology.

Another alternative liquid fuel not considered on this thread is di-methyl-ether. Its nontoxic enough to used as a propellant in personal care items, yet its readily burned in diesel internal combustion engines. I dont know much about the BTU's in vs BTU's out characteristics. In diesel engines it generates minimal soot because there are no carbol-carbon bonds.

A good survey of alternative IC engine liquids as well as coping strateges can be found in Ken Deffeyes' book "Beyond oil : the view from Hubbert's peak ".