Ethanol: Don't Knock It

"Gasoline is growing scarcer, and therefore dearer, all the time... Automobiles cannot use gasoline for all time, of that I am sure, and alcohol seems to be the best substitute that has yet appeared." (US House and Senate hearings on the "Free Alcohol" bill, 1906)

This statement could easily have been made today. High quality oil was becoming scarce by the 1920s and lower grade oil was being brought onto the market, resulting in engine knock in automobiles. As a result there was a great deal of research into the usability of low quality oil in automobile engines.

Eventually GM selected tetra-ethyl lead (TEL) as an anti-knock gasoline additive. This solution, known today as "leaded gasoline," was the most profitable alternative and therefore GM would lead the public to believe that it was the only alternative. Other viable additives were available, including ethyl alcohol which was not patentable. Certainly there was pressure on GM research to come up with a patentable solution.

Studies of Ethyl alcohol (Ethanol) as a fuel for internal combustion engines began in 1906 where it was found that significantly higher engine compression ratios could be achieved with alcohol at lower B.T.U. At that time it was determined that the fuel economy was virtually equal for alcohol and gasoline. The U.S. Geological Service (USGS) concluded that alcohol was "a more ideal fuel than gasoline" with better efficiency, though at a higher cost. Alcohol had many advantages over gasoline such as no smoke or disagreeable odors.

Furthermore, TEL proved to be dangerous. In the 1924 / 1925 time frame, several workers died and many others were exposed to lead poisoning at two separate TEL manufacturing facilities. Thomas Midgley Jr.[1] from GM subsequently told the government that no alternatives existed.

"So far as science knows at the present time, tetraethyl lead is the only material available which can bring about these [antiknock] results, which are of vital importance to the continued economic use by the general public of all automotive equipment, and unless a grave and inescapable hazard exists in the manufacture of tetraethyl lead, its abandonment cannot be justified." - Thomas Midgley Jr. 1925.

At this particular time, farmers were hurting as a result of prohibition and needed new markets for grain products. It was certainly plausible for the farm industry to produce enough ethanol to replace TEL as the anti-knock additive of choice.

However, The Public Health Service, after investigating the accidents, allowed leaded gasoline to remain on the market. It is safe to say that in this instance the PHS did not do its job and TEL-enhanced gasoline continued to dominate. Finally, in 1986, the United States banned TEL, not because of health concerns, but because of TEL's adverse effect on catalytic converters. Meanwhile, other countries such as the UK curtailed the use of alkyl leads due to the adverse health effects of lead emissions, especially on children.

Today the United States is a world leader in ethanol production and makes over 7 billion gallons of ethanol-blended gasoline per year. This represents approximately 12% of fuel sales including E85 (85% ethanol 15% gasoline) and E10 (10% ethanol 90% gasoline).

Although many people complain about ethanol-blended gasoline, they often lose sight of the reasons for its use. Not only is it better for the environment, it will also enable car owners to enjoy the use of gasoline for many years to come for two primary reasons: (1) it reduces petroleum consumption; (2) it enables the gasoline producers to use lower grade oil.

[1] Thomas Midgley Jr. was the chief fuel researcher at General Motors. He developed both the tetra-ethyl lead (TEL) additive to gasoline and chlorofluorocarbons (CFCs). One historian declared that Midgley "had more impact on the atmosphere than any other single organism in Earth history."

Steve Auger is the author of Blog On Smog

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