Alcohol is a viable fuel for vehicles. Ford Model T's were run on it during
the depression; some drag racers use it, Indy race cars use it, and cars in
some overseas countries run on alcohol fuel. In Canada, the auto
manufacturers are just starting to design cars that can run on either
gasoline or E85 (a mixture or 85% ethyl alcohol and 15% gasoline). It is
relatively easy to modify a vehicle to run on alcohol, although fuel
injected vehicles will need a little help from a computer programmer, so why
are there no alcohol fuel stations?
The answer is cost! Even though alcohol is manufactured from a renewable
resource, and it is fairly simple to manufacture (just ask a moonshiner!),
the cost of producing a litre of alcohol is more than the cost of producing
a litre of gasoline. As the cost of gasoline rises, producing alcohol for
fuel will become economically practical.
There are other disadvantages of using alcohol. The heat content of a litre
of alcohol is less than gasoline so more alcohol must be used to achieve the
same power levels. The penalty is decreased fuel economy and lower driving
range without installing bigger fuel tanks. Another disadvantage of alcohol
as a fuel is its lower volatility. During hot weather driving, the fuel
vaporises easily and vapour lock (fuel boiling in the lines) can occur. This
can make the engine run rough or even prevent it from running. Sealed and
pressurised fuel systems on fuel injected vehicles would tend to prevent the
fuel from boiling, so this may not be a big concern for modern designs.
There are a couple advantages of alcohol as a fuel. It mixes easily with
water and prevents ice formation in cold weather. There is no need to add
gas line de-icer. It also has a higher octane rating than gasoline, which
allows engine compression ratios to be increased and ignition timing to be
advanced for better performance.
Currently, there is only one major fuel company in Canada supplying fuel
with alcohol in it. Mohawk sells both regular and premium fuel with a blend
of alcohol and gasoline. Advertisements for the fuel claim that up to 40%
fewer emissions can be obtained by using this fuel. This can be true, but it
depends on the age of the vehicle you are driving.
Alcohol is an oxygenate. This means that the alcohol in the fuel breaks down
as it is being burned to produce extra oxygen. The extra oxygen combines
with the fuel to produce more complete combustion, more power, and lower
emissions. However, this process only works well when there is an excess of
fuel already entering the engine. Many carburettor-equipped vehicles would
produce fewer emissions by using fuel with alcohol in it, but if your engine
was already running with a lean fuel mixture, adding alcohol to the fuel can
cause a hesitation or stumble.
Fuel injected vehicles use an oxygen sensor to fine-tune the fuel delivery.
If fuel with alcohol is used, the oxygen sensor measures the extra oxygen
and signals the computer to supply more fuel. The engine should not operate
any different or produce fewer emissions in this situation.
Many consumers refer to gasoline and alcohol fuel blends as "Gasohol".
Gasohol got a bad name in the United States during the fuel shortage crisis
of the early 1970's. Some fuel companies were using too much alcohol, or the
wrong type of alcohol! This problem has not existed in Canada and has been
corrected south of the border.
Two types of alcohol are available for blending with gasoline: ethyl alcohol
(grain alcohol) and methyl alcohol (wood alcohol). Ethyl alcohol can be used
by itself as a fuel but when it is marketed as a mix with gasoline it is
limited to 10% by volume. This is acceptable by most automobile
manufacturers. If in doubt, check your owner's manual.
Methyl alcohol on the other hand is very corrosive. Most manufacturers do
not recommend the use of it. Those that allow it specify a maximum of 3 to
5% and that anti-corrosion additive must be part of the fuel as well.
Fortunately, methyl alcohol is not used with fuel in most of North America.
It is just too corrosive.
General Motors did evaluate a fleet of test vehicles in Alberta on M85 fuel
(85% methyl alcohol and 15% gasoline) a few years ago. Stainless steel was
used for fuel tanks, fuel lines, gauge sending units, and other special
parts of the fuel system. This was necessary to resist the corrosive nature
of the fuel. The vehicles ran well, but fuel injector problems were frequent
because the fuel would attack the conventional gasoline injectors. The test
fleet is no longer in service.
Alcohol has the potential to replace gasoline in the future or at least
extend our gasoline supply. The successes in development of other alternate
energy sources may limit the use of alcohol as a fuel, but there has been
some work in using alcohol in conjunction with fuel cells to produce power
for tomorrow's vehicles. Alcohol has been used as a fuel for centuries.
Maybe it will be the fuel of the future too.
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