48. What is the difference between ethanol and methanol?
They are both alcohols. Ethanol is fermented alcohol made prima- rily from corn. Methanol is made from natural gas or coal,
and is also known as "wood alcohol." Methanol is highly corrosive, more volatile than ethanol, and can be damaging to plastic
and rubber fuel system components (elastomers). Because of its abundance, methanol will probably be used as a fuel in the
future, but it is not as environmentally clean as ethanol, is not renewable, and might be an imported product.
49. What are MTBE and ETBE?
Ethyl Tertiary Butyl Ether (ETBE) and Methyl Tertiary Butyl Ether (MTBE) are both high octane, low volatility, oxygenated
fuel components made by combining alcohol with isobutylene from oil refineries. MTBE which is preferred by the major oil companies
is the largest selling oxygenate today, while ethanol is second. ETBE is currently manufac- tured by Koch Refinery in Pine
Bend, Minnesota, Marathon Oil in Robinson, Illinois, and Amoco Oil in Yorktown, Virginia. ETBE is made with an ethanol base,
and MTBE is madeXwith a methanol base.
50. Why don't we use pure ethanol, instead of a 10% blend?
Brazil is able to operate nearly half of its cars on pure ethanol, but it would be neither necessary nor practical to do
it here at this time. All of the excess corn capacity in this country would be needed to produce enough ethanol for a 10%
blend with all gasoline. In addition, most engines need some modification to run on pure ethanol. Fortunately, a 10% level
requires no engine modification, yet still makes significant immediate contributions to carbon monoxide reduction.
51. Do we need the high-octane gasolines that the major oil companies are promoting?
An octane number is only a measure of gasoline's ability to resist pre-ignition, also known as "knocking" or "pinging."
If your vehicle does not ping or "run on" after the ignition is turned off, then you are using a gasoline with a high enough
octane number. Any extra money that you pay for higher octane is wasted, as it will not contribute to increased mileage. Since
fewer gallons of high octane gasoline than low octane gasoline can be made from a barrel of crude, it is a poor national energy
strategy to waste crude oil to produce unnecessary octane.
52. Does an ethanol blend require special handling?
Only in special circumstances. The gasoline marketer should pump any accumulated water from the storage tank, and add a
final filter to the dispensing hose. Since seasonally used small engines such as chainsaws and outboard motors are susceptible
to water contamination, it is also wise to check them for the presence of water and drain the tank if necessary. These precautions
are nothing more than good housekeeping practices, but adhering to them will assure optimum performance of an ethanol blend.