Environmental Engineering Reference
In-Depth Information
Other Fuels
Other fuels have been discussed as possible substitutes
for gasoline or electricity from the power grid. The
main candidates are ethanol, natural gas, and hydrogen.
Ethanol made from corn is what the US program man-
dates now, though more advanced ways of making ethanol
are in the research phase. Ethanol is discussed in detail in
Chapter
on biofuels. Here I only say that corn ethanol
takes about as much energy to make as is in the gasoline it
displaces, results in the emission of nearly as much green-
house gas as gasoline, is more expensive than gasoline for
the same energy content, and has driven up the price of
food. Corn ethanol is a subsidy for agribusiness, not a
route to greenhouse gas reduction. There are promising
new biofuels under development, but none have yet
reached the stage of commercial-scale production.
Natural gas can be used directly in an ICE. Honda
makes a compressed natural gas version of its Civic model
(Civic CNG) which costs about
$
and is rated by
the California Air Resources Board as an
“
advanced tech-
nology partial zero emission vehicle.
In residences, nat-
ural gas is widely used for heating and cooking. Five years
ago it was possible to purchase a compressor that would
hook to a home natural gas line to
”
t
know if they are still available. Back then those who had a
CNG car simply hooked them up to the natural gas line at
night and drove them out in the morning. There are
refueling stations where you can get the tank recharged.
The CNG is popular in places where natural gas is cheap.
Since natural gas produces lower greenhouse gas emis-
sions than does the amount of gasoline with the same
fill a CNG tank. I don
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