Produced by natural gas under similar conditions an

produced by natural gas under similar conditions
• An alternative method suggested for H
2
storage/transportation
is to convert it into solid metal hydrides, MH
2
.

Alternative Fuels
• Hydrogen gas is most efficient and clean fuel
• It produces the most energy per gram,
• Transportation and storage are difficult
• It requires a much large fuel tank than gasoline;
• May be compressed into liquid form, but poses explosion
hazard
• An alternative way is to convert it into a solid metal hydride
(MH
2
) – one that is able to release H
2
when heated.
• Most likely the hydrogen will be used to power fuel cells that
will be installed in automobiles

Alternative Fuels
• Oil shale
– Shale rocks contain complex HC called kerogen
– Huge deposits in western states, especially Colorado;
– Kerogen is not fluid like petroleum - cannot be pumped;
– Rocks containing fuel must be heated to >250
o
C to
decompose the kerogen into smaller HC molecules;
– Process produces large quantities of waste rocks – a
negative environmental impact.

Alternative Fuels
• Ethanol:
– Produced by fermentation of sugar (from sugar cane or corn)
– Pure ethanol produces about 27 kJ/g of energy
– Use as fuel supplement
– Added to gasoline as gasohol (which contains ca. 10% ethanol)
– Pure ethanol not suitable for motor fuel in USA, especially in
winter, because it does not vaporize easily in cold climate.
– Pure ethanol is widely used as motor fuel in Brazil where the
climate is warmer.

Alternative Fuels
• Methanol:
– Methanol produces about 20 kJ/g of energy
when completely combusted
– It has been used in race cars as a mixture of
85% methanol and 15% gasoline.
– California is evaluating methanol as motor
fuel
– Arizona and Colorado are considering similar
step.

New Energy?