Compositions and methods for forming
hexane, and, optionally,
gasoline and / or components of a
gasoline composition, from fermentable sugars are disclosed. The sugars are fermented using a
bacteria or
yeast that predominantly forms
butyric acid. The
butyric acid is subjected to Kolbe or photo-Kolbe
electrolysis to form
hexane. The
hexane can be subjected to catalytic, reforming and / or
isomerization steps to form higher
octane products, which are or can be included in
gasoline compositions. In one aspect, the fermentable sugars are derived from lignocellulosic materials such as wood products, switchgrass, or agricultural wastes. These materials are delignified to form
lignin,
cellulose and
hemicellulose. The
cellulose and
hemicellulose are depolymerized to form glycose and
xylose, either or both of which can be fermented by the
bacteria. The
lignin can be used to generate
heat energy and / or
electric energy for use in one or more process steps, such as the
fermentation, product isolation, Kolbe
electrolysis,
catalytic reforming and / or
isomerization steps. Alternatively, the
lignin can be converted to synthesis gas, which can then be subjected to Fischer-Tropsch synthesis, or converted to
methanol and / or
ethanol. Thus, the methods described herein can convert
biomass to a fuel composition or fuel additive, which can be used in a conventional gasoline engine, unlike traditional fuels such as
ethanol or
biodiesel.