Alternative fuel compositions, blends of the alternative fuel compositions and
gasoline, and methods for their preparation and use are disclosed. The alternative fuel compositions ideally include
ethanol,
isopropyl alcohol, and one or more of sec-
butanol and t-
butanol, and ideally include no more than 3%
methanol, and no more than 15% C5 or higher alcohols. The fuel compositions can be prepared using Fischer-Tropsch synthesis to convert
syngas to a product
stream comprising C2-4 olefins, and hydrolyzing these olefins. The process facilitates isolation of C2-4 alkanes, because the
boiling point difference of these alkanes is significantly lower than that of the C2-4 alcohols. Ideally, the compositions provide more energy per
unit volume than E85, even without the addition of
gasoline, although the compositions can be blended with
gasoline in any desired ratio. The resulting alternative fuel can be derived, at least in part, from renewable resources, in that the
syngas can be derived from renewable resources, and a significant portion of the molecule is derived from the water used to hydrolyze the olefins. The alternative fuel compositions, and blends thereof with gasoline, can help reduce U.S. dependence on foreign
crude oil.